JP2009265083A - Temperature measuring method, temperature control system, air flow measuring device, and heating value measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature measuring method, an air flow measuring device and a heating value measuring device for a computer room using an optical fiber which can measure a temperature distribution of the computer room efficiently with sufficient accuracy. <P>SOLUTION: A first optical fiber 24a is installed so as to pass near a grill a of a free access floor 15 and near an inlet port b inside a rack 11 in which a peak temperature is a relatively low temperature. Further, a second optical fiber 24b is installed so as to pass near CPU c in which the peak temperature is a relatively high and near an exhaust port d and near a ceiling e outside the rack. Thereby, a temperature difference of adjacent measuring points becomes small, therefore excellent measuring accuracy is obtained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a temperature measurement method and a temperature control system for a computer room in which a plurality of computers are installed, an air flow measuring device, and a calorific value measuring device.

  In recent years, with the advent of the advanced information society, a large amount of data has been handled by computers (computer devices), and a large number of computers such as data centers are installed and managed in one room. ing. Under such circumstances, a large amount of heat is generated from the computer, causing malfunction or failure, and thus means for cooling the computer is required.

  FIG. 1 is a schematic diagram showing the structure of a general medium / large-scale computer room. As shown in FIG. 1, the room of the computer room is divided into an equipment installation area 10 and a free access floor 15. A plurality of racks (server racks) 11 are arranged in the device installation area 10, and each rack 11 stores a plurality of computers (blade servers, etc.). In addition, the device installation area 10 is provided with a management space necessary for management of a passage and a computer for the administrator to pass.

  The free access floor 15 is provided under the floor of the equipment installation area 10. On the free access floor 15, various cables 16 such as power cables and communication cables connected to the racks 11 are accommodated in a cable duct 17.

  Cold air is supplied from the air conditioner 19 to the free access floor 15. A ventilation opening (grill) 12 is provided under the floor of the equipment installation area 10. Cold air is supplied from the free access floor 15 to the vicinity of the intake opening of the rack 11 through the ventilation opening 12, and the computers in the rack 11 are connected. It is designed to cool.

  By the way, from the viewpoint of energy saving and prevention of global warming, reduction of electric power consumed in the data center is demanded. For this reason, even in data centers, it is required not to simply cool the computer, but to appropriately control the air conditioning equipment and the like according to the usage status of the computer.

  In order to enable long-distance temperature measurement, a set of optical fiber type distributed temperature measuring devices, computers and optical switches are used. The technology of the measurement system and an optical fiber temperature sensor for each of multiple systems of lighting equipment, and a switch (line selector) placed between these optical fiber temperature sensors and the optical fiber temperature detector. Technology to monitor the temperature, and laying multiple optical fibers along the length of the road, individually measuring the temperature distribution of the road with each optical fiber, and sending those measurement data to the monitoring station Technology for batch management is known. A technique for measuring wind speed using an optical fiber thermometer is also known.

JP 7-159244 A Japanese Patent Laid-Open No. 7-135692 JP 2001-296189 A JP 2002-267242 A JP 2008-27888 A JP-A-5-107121 JP-A-6-174561

  In order to reduce power consumption in the data center while avoiding malfunctions and failures of computers due to heat, it is necessary to measure the temperature distribution of the computer room as needed and to control the air conditioning equipment etc. as appropriate according to the measurement results. . In order to measure the temperature distribution in the computer room, it is conceivable to install a plurality of temperature sensors (such as temperature sensor ICs or thermocouples) in a free access floor or rack, for example. However, since a large number of racks are installed in the computer room, the number of temperature sensors becomes enormous, and there is a problem that the cost required for installation and maintenance management of the temperature sensors increases. Moreover, since the rate of failure increases as the number of temperature sensors increases, there is also a problem that the reliability is not sufficient.

  Therefore, it has been proposed to monitor the temperature distribution in the computer room (including the rack and the free access floor) using optical fibers. However, at present, techniques such as an optical fiber laying method suitable for measuring a temperature distribution in a computer room and how to reflect a temperature measurement result in the operation of an air conditioner or the like have not been established.

  Accordingly, an object of the present invention is to provide a computer room temperature measurement method using an optical fiber that can efficiently and accurately measure the temperature distribution of the computer room. It is another object of the present invention to provide a computer room temperature control system that appropriately controls air conditioning equipment and the like based on temperature measurement results using an optical fiber and suppresses power consumption of the computer room.

  It is another object of the present invention to provide an air volume measuring device capable of measuring the air volume of air passing through a space such as a rack with good accuracy.

  It is another object of the present invention to provide a calorific value measuring device that measures the calorific value in a space such as a rack using an optical fiber.

  According to one aspect, in the temperature measurement method for a computer room in which a plurality of racks for storing a plurality of computers or storages are installed, a plurality of first temperatures set at least one of the inside and the outside of the plurality of racks. A first optical fiber is laid so as to pass through the measurement point, and a plurality of second temperatures set at least one of the inside and the outside of the plurality of racks and having a peak temperature higher than that of the first temperature measurement point A second optical fiber is laid so as to pass through the measurement point, laser light is introduced into each of the first optical fiber and the second optical fiber, and backscattered light is detected to detect the first optical fiber and A computer room temperature measurement method for measuring a temperature distribution along the length direction of the second optical fiber is provided.

  In temperature measurement using an optical fiber, a measurement error increases when the distance between measurement points is short and the temperature difference is large. In this case, for example, it is conceivable that an optical fiber is wound around the measurement point and the distance between adjacent measurement points is substantially increased. However, in this case, there is a disadvantage that the length of the optical fiber per rack becomes long and the cost increases.

  In the above-described one aspect, the first optical fiber laid so as to pass through the relatively low temperature measurement point (first measurement point) and the relatively high temperature measurement point (second measurement point) are passed. The temperature distribution in the computer room is measured with the second optical fiber laid on the wall. By laying the optical fiber as described above, the temperature difference between adjacent measurement points is reduced, and the measurement error is also reduced.

  The first optical fiber and the second optical fiber may be individual optical fibers, and a part (outward path) of one optical fiber is used as the first optical fiber and the other part (return path) is used as the second optical fiber. It is good also as an optical fiber.

  According to another aspect, in a temperature control system for a computer room in which a plurality of racks for storing a plurality of computers or storages are installed, a control unit in which a target temperature of a measurement point set in the computer room is set; An optical fiber detector that measures the temperature of the measurement point with an optical fiber installed in the computer room; and an air-conditioning cooling facility installed in the computer room, and the control unit includes the optical fiber detector. There is provided a temperature control system for controlling the air conditioning cooling equipment so that the temperature of the measurement point measured by the above becomes the target temperature.

  In the above viewpoint, the temperature distribution in the computer room is measured by the optical fiber detector. By using the optical fiber detector, the temperature distribution in the computer room can be measured in real time. Based on the temperature distribution measurement result by the optical fiber detector, the control unit installs air conditioning cooling equipment (air conditioner, cooling fan, chilled water supply pump, grill adjustment mechanism, etc.) so that the temperature at each measurement point becomes the target value. Control. As a result, the temperature distribution in the computer room changes, but the temperature change is detected by the optical fiber detector and transmitted to the controller.

  Thus, in the above viewpoint, the temperature of the measurement point in the computer room is measured in real time by the optical fiber detector, and the air conditioning cooling equipment is controlled by the control unit based on the result. Thereby, accumulation of heat, supercooling, etc. can be avoided appropriately, and the power consumption of the computer room can be reduced.

  According to still another aspect, in a computer room temperature control system in which a plurality of racks for storing a plurality of computers are installed, a control unit in which a target temperature of a measurement point set in the computer room is set; An optical fiber detector that measures the temperature of the measurement point by an optical fiber laid in a computer room, a load balancing server that determines a computer that processes the new job according to the calculation amount of the new job, a calculation amount, and a CPU (Central Processing Unit) comprising a database storing the relationship with temperature, and having a state variable storage unit for outputting a signal corresponding to the calculation amount of the new job to the control unit using the database, and the control unit According to the target temperature, the temperature measurement result by the optical fiber detector, and the signal output from the state variable storage unit. Temperature control system for controlling the air-conditioning cooling system provided in the calculation unit room are provided.

  The temperature control system according to the above aspect includes a load distribution server that determines a computer that processes a new job, and a state variable storage unit that includes a database that stores the relationship between the calculation amount and the CPU temperature.

  When a new job is input, the load distribution server determines a computer that processes the new job and outputs information indicating the calculation amount of the new job to the state variable storage unit. The state information storage unit refers to the database and outputs a signal corresponding to the calculation amount of the new job to the control unit. Based on the target temperature, the temperature at the measurement point measured by the optical fiber detector, and the signal output from the state storage unit, the control unit is equipped with air conditioning cooling equipment (air conditioner, cooling fan, cooling water supply pump, Control the grill adjustment mechanism.

  In the above aspect, since the relation between the calculation amount and the CPU temperature is stored in the database of the state variable storage unit, the control unit can execute the computer before the computer starts the job processing or at the same time as the job processing starts. It is possible to control the air conditioning cooling equipment related to the, and to suppress the temperature rise of the computer.

  In general, the higher the temperature, the greater the leakage current of the CPU (transistor), and the greater the power consumption of the computer. In the above temperature control system, the air conditioning cooling equipment is controlled so that the temperature rise of the computer is suppressed before or simultaneously with the start of processing of a new job by the computer, thereby further reducing the power consumption of the computer room. be able to.

  According to still another aspect, an optical fiber laid on each of the air inlet and the air outlet of a container having an air inlet and an air outlet and housing a heating element therein, and laser light is introduced into the optical fiber. An optical fiber detector that detects backscattered light and measures the average temperature at the intake and exhaust ports, and the difference in average temperature between the intake and exhaust ports detected by the optical fiber detector and the heating element There is provided an air volume measuring device having an arithmetic unit for calculating an amount of air flowing through the intake port and the exhaust port from a calorific value.

  The amount of air flowing through a container (such as a rack and an electronic device housing) in which a heating element is stored is the average temperature of the air flowing through the intake and exhaust ports of the container and the amount of heat generated from the heating element. Can be calculated. The amount of heat generated from the heating element can be grasped relatively accurately, for example, by measuring the power consumed by the heating element.

  On the other hand, it is conceivable that the average temperature of the air flowing through the intake port and the exhaust port of the container is obtained by arranging a number of temperature sensors such as thermocouples and calculating the average value of the detected temperatures. However, in that case, there is a problem that the number of temperature sensors increases and the cost required for installation and maintenance management increases. Therefore, in the air flow measurement method, an optical fiber is used as the temperature sensor. When an optical fiber is used as the temperature sensor, the temperature is measured with the entire optical fiber arranged in the measurement region, so that a wide range of average temperatures can be detected easily and with high accuracy. Thereby, the amount of air (air volume) flowing through the container can be obtained with high accuracy.

  Furthermore, according to another aspect, the temperature measuring optical fiber laid on each of the air inlet and the air outlet of the container having an air inlet and an air outlet and housing the heating element therein, and the air inlet of the container Alternatively, an optical fiber for measuring wind speed that is installed in an exhaust port and measures the average flow velocity of air, and a laser beam is introduced into the optical fiber for temperature measurement and the optical fiber for wind speed measurement to detect backscattered light, and the container Measuring the average temperature of the intake and exhaust ports of the container, and measuring the average flow velocity of air at the intake and exhaust ports of the container, and the average at the intake and exhaust ports detected by the photodetector There is provided a calorific value measuring device having a calculation unit for calculating a calorific value of the heating element from a difference in temperature and an average air flow velocity at the inlet or exhaust port of the container.

  A technique for measuring the flow velocity of a fluid using an optical fiber is known. The flow rate of air flowing through the intake or exhaust port of the container is measured using an optical fiber, and the average temperature at the intake and exhaust ports is measured using, for example, an optical fiber. The amount of heat generated can be determined. By using the optical fiber, it is possible to accurately measure the average flow rate of the air flowing through the intake port or the exhaust port, and as a result, the calorific value can be obtained with high accuracy.

FIG. 1 is a schematic diagram showing the structure of a general medium / large-scale computer room. FIG. 2 is a schematic diagram showing a configuration of a temperature distribution measuring apparatus using an optical fiber. FIG. 3 is a diagram showing a spectrum of backscattered light. FIG. 4 is a diagram illustrating an example of a time-series distribution of the intensity of Raman scattered light. 5 calculates the I ₁ / I ₂ ratio for each time based on the time-series distribution of the intensity of Raman scattered light in FIG. 4 and converts the horizontal axis (time) in FIG. It is a figure which shows the result of having converted signal intensity | strength) into temperature. FIG. 6 is a side view showing racks arranged in the computer room. FIG. 7 is a schematic diagram (side view) showing a first example (comparative example) of laying optical fibers. FIG. 8 is a schematic diagram (top view) showing a first example (comparative example) of laying optical fibers. FIG. 9 is a diagram showing a measured temperature distribution when an optical fiber is arranged in an environment having a temperature of 25 ° C. and heat of 80 ° C. is applied so as to form a step-type temperature distribution centering on a position 5 m from the light source. . FIG. 10 is a diagram showing the actual temperature distribution and the measured temperature distribution when the optical fiber is laid as shown in FIGS. FIG. 11 is a schematic diagram (side view) showing a second example (comparative example) of laying optical fibers. FIG. 12 is a schematic diagram (top view) showing a second example (comparative example) of laying optical fibers. FIG. 13 is a diagram showing an actual temperature distribution and a measured temperature distribution when an optical fiber is laid as shown in FIGS. FIG. 14 is a schematic diagram (side view) showing a third example (example) of laying optical fibers. FIG. 15 is a schematic diagram (top view) showing a third example (example) of laying optical fibers. FIG. 16 is a diagram showing an actual temperature distribution and a measured temperature distribution when the second optical fiber is laid as shown in FIGS. 14 and 15. FIG. 17 is a diagram showing an actual temperature distribution and a measured temperature distribution when the first optical fiber is laid as shown in FIGS. 14 and 15. FIG. 18 is a schematic diagram (side view) showing a fourth example (example) of laying optical fibers. FIG. 19 is a schematic diagram (top view) showing a fourth example (example) of laying optical fibers. FIG. 20 is a diagram showing an actual temperature distribution and a measured temperature distribution when the second optical fiber is laid as shown in FIGS. 18 and 19. FIG. 21 is a schematic diagram illustrating an example in which temperature measurement is performed using two single-channel single-ended optical fiber detectors. FIG. 22 is a schematic diagram showing an example of temperature measurement using a two-channel single-ended optical fiber detector. FIG. 23 is a schematic diagram showing an example in which temperature measurement is performed using a two-channel loop optical fiber detector. FIG. 24 is a schematic diagram showing an example of temperature measurement using a one-channel loop optical fiber detector. FIG. 25 is a schematic diagram illustrating a first configuration example of a temperature control system for a computer room according to the embodiment. FIG. 26 is a conceptual diagram showing the concept of the temperature control method in the first configuration example. FIG. 27 is a schematic diagram illustrating a second configuration example of a temperature control system for a computer room according to the embodiment. FIG. 28 is a conceptual diagram showing the concept of the temperature control method in the second configuration example. FIG. 29 is a schematic diagram showing an example of an embodiment applied to a hybrid cooling method combining water cooling and air cooling. FIG. 30 is a schematic diagram illustrating an air volume measuring device and an air volume measuring method according to the embodiment. FIG. 31 is a schematic diagram showing an installed state of the optical fiber in the embodiment of the air volume measuring method. FIG. 32 is a schematic diagram showing a laying state of the point measurement type temperature sensor (thermocouple) in the comparative example of the air volume measuring method. FIG. 33 is a diagram illustrating an example of the temperature at each measurement point measured by a point measurement type temperature sensor (thermocouple). FIG. 34 is a diagram showing the result of simulating the measured temperature distribution on the intake side measured with an optical fiber and a thermocouple. FIG. 35 is a diagram showing the result of simulating the measured temperature distribution on the exhaust side measured with an optical fiber and a thermocouple. FIG. 36 is a diagram collectively showing measurement results of average temperature, air volume, and wind speed in Examples and Comparative Examples. FIG. 37 is a schematic diagram illustrating a calorific value measuring device and a calorific value measuring method according to the embodiment.

(Temperature distribution measurement)
Next, before describing the embodiment, a preliminary matter for facilitating understanding of the embodiment will be described.

  FIG. 2 is a schematic diagram showing a configuration of a temperature distribution measuring apparatus using an optical fiber. Moreover, FIG. 3 is a figure which shows the spectrum of backscattered light.

  As shown in FIG. 2, the temperature distribution measuring apparatus includes a laser light source 21, lenses 22 a and 22 b, a beam splitter 23, an optical fiber 24, a wavelength separation unit 25, and a photodetector 26. .

  Laser light having a predetermined pulse width is output from the laser light source 21 at a constant cycle. This laser light enters the optical fiber 24 from the light source side end of the optical fiber 24 through the lens 22a, the beam splitter 23, and the lens 22b. In FIG. 2, 24 a indicates the core of the optical fiber 24, and 24 b indicates the cladding of the optical fiber 24.

  Part of the light that has entered the optical fiber 24 is backscattered by the molecules constituting the optical fiber 24. As shown in FIG. 3, the backscattered light includes Rayleigh scattered light, Brillouin scattered light, and Raman scattered light. Rayleigh scattered light is light having the same wavelength as incident light, and Brillouin scattered light and Raman scattered light are light having wavelengths shifted from the incident wavelength.

  The Raman scattered light includes Stokes light shifted to a longer wavelength side than incident light and anti-Stokes light shifted to a shorter wavelength side than incident light. The shift amount of Stokes light and anti-Stokes light depends on the wavelength of the laser light, the material constituting the optical fiber 24, and the like, but is usually about 50 nm. Moreover, although both the intensity of Stokes light and anti-Stokes light changes with temperature, the amount of change of Stokes light with temperature is small, and the amount of change of anti-Stokes light with temperature is large. That is, it can be said that the Stokes light has a small temperature dependency, and the anti-Stokes light has a large temperature dependency.

  As shown in FIG. 2, these backscattered light returns through the optical fiber 24 and exits from the light source side end. Then, the light passes through the lens 22 b, is reflected by the beam splitter 23, and enters the wavelength separation unit 25.

  The wavelength separator 25 includes beam splitters 31a, 31b, and 31c that transmit or reflect light according to the wavelength, optical filters 33a, 33b, and 33c that transmit only light of a specific wavelength, and optical filters 33a, 33b, and 33c. And condensing lenses 34a, 34b, and 34c for condensing the light that has passed through the light receiving portions 26a, 26b, and 26c of the photodetector 26, respectively.

  The light incident on the wavelength separator 25 is separated into Rayleigh scattered light, Stokes light, and anti-Stokes light by the beam splitters 31a, 31b, 31c and the optical filters 33a, 33b, 33c, and the light receivers 26a, 26b of the photodetector 26. , 26c. As a result, signals corresponding to the intensity of Rayleigh scattered light, Stokes light, and anti-Stokes light are output from the light receiving units 26a, 26b, and 26c.

  Note that the pulse width of the backscattered light input to the photodetector 26 is related to the length of the optical fiber 24. For this reason, the interval between the laser pulses output from the laser light source 21 is set so that the backscattered light from each laser pulse does not overlap. If the power of the laser beam is too high, a stimulated Raman scattering state occurs and correct measurement cannot be performed. For this reason, it is important to control the power of the laser light source 21 so as not to be in the stimulated Raman scattering state.

As described above, since the Stokes light has a small temperature dependency and the anti-Stokes light has a large temperature dependency, the temperature at the position where the backscattering can be evaluated by the ratio between the two. The intensity ratio of Stokes light and anti-Stokes light is as follows when the optical phonon angular frequency in the optical fiber is ω _k , the incident light angular frequency is ω ₀ , the Planck constant is h, the Boltzmann constant is k, and the temperature is T: Is expressed by the following equation (1).

  That is, if the intensity ratio between Stokes light and anti-Stokes light is known, the temperature at the position where backscattering occurs can be calculated from equation (1).

  By the way, the backscattered light generated in the optical fiber 24 is attenuated while returning through the optical fiber 24. Therefore, in order to correctly evaluate the temperature at the position where backscattering occurs, it is necessary to consider the attenuation of light.

  FIG. 4 is a diagram illustrating an example of a time-series distribution of the intensity of Raman scattered light, with time on the horizontal axis and signal intensity output from the light receiving unit of the photodetector on the vertical axis. Stokes light and anti-Stokes light are detected by the photodetector for a certain period immediately after the laser pulse is incident on the optical fiber. When the temperature is uniform over the entire length of the optical fiber, the signal intensity decreases with the passage of time when the laser pulse is incident on the optical fiber. In this case, the time on the horizontal axis indicates the distance from the light source side end of the optical fiber to the position where backscattering occurs, and the decrease in signal intensity over time indicates the attenuation of light by the optical fiber.

When the temperature is not uniform over the length of the optical fiber, for example, when there are a high temperature portion and a low temperature portion along the length direction, the signal intensity of Stokes light and anti-Stokes light is not attenuated uniformly, As shown in FIG. 4, peaks and valleys appear on the curve indicating the change in signal intensity with time. In FIG. 4, the intensity of anti-Stokes light at a certain time t is I ₁ , and the intensity of Stokes light is I ₂ .

5 calculates the I ₁ / I ₂ ratio for each time based on the time-series distribution of the intensity of Raman scattered light in FIG. 4 and converts the horizontal axis (time) in FIG. It is a figure which shows the result of having converted signal intensity | strength) into temperature. As shown in FIG. 5, the temperature distribution in the length direction of the optical fiber can be measured by calculating the intensity ratio (I ₁ / I ₂ ) between the anti-Stokes light and the Stokes light.

  Note that the intensity of Raman scattered light (Stokes light and anti-Stokes light) at the position where backscattering varies with temperature, but the temperature dependence of the intensity of Rayleigh scattered light is so small that it can be ignored. Therefore, it is preferable to specify the position where backscattering occurs from the intensity of Rayleigh scattered light, and to correct the intensity of Stokes light and anti-Stokes light detected by the photodetector according to the position.

  FIG. 6 is a side view showing racks arranged in the computer room. The cold air supplied from the air conditioner to the free access floor 15 is supplied to the equipment installation area 10 through the grill (ventilation opening) 41. An intake port is provided on the back side of the rack 11, and cold air is taken into the rack 11 through the intake port. And after cooling CPU etc. of each computer (blade server etc.) accommodated in the rack 11, it is discharged | emitted outside the rack 11 through the exhaust port of the front side of the rack 11. FIG. In this embodiment, it is assumed that a plurality of computers (computers such as blade servers) are stored in the rack, but the inside of the rack in which a plurality of storages (storage devices) are stored or in the vicinity of the rack. The basic configuration is the same when measuring temperature.

  In FIG. 6, a to e indicate temperature measurement points necessary for controlling the air conditioning cooling facility. a is a temperature measurement point near the grill of the free access floor 15, b is a temperature measurement point near the intake port in the rack 11, c is a temperature measurement point near the CPU of the computer stored in the rack 11, and d is the rack 11. The temperature measurement point in the vicinity of the inner exhaust port, e is the temperature measurement point of the ceiling zone near the exhaust port outside the rack 11.

  7 and 8 are schematic views showing a first example (comparative example) of laying optical fibers. FIG. 7 shows the laid state of the optical fiber when the rack is viewed from the side, and FIG. 8 shows the laid state of the optical fiber when the rack is viewed from above. In FIG. 8, a thick solid line indicates an optical fiber disposed in the equipment installation area (including the inside of the rack) 10, and a thick broken line indicates an optical fiber disposed on the free access floor 15. Here, it is assumed that three computers are stored in the rack 11.

  As shown in FIG. 7, in the first example, the optical fiber 24 is connected to the free access floor 15 in the vicinity of the grille a in the vicinity of the air inlet in the rack 11 b in the vicinity of the top plate in the rack 11 f in the outer side of the rack 11 (front surface). E) near the ceiling e-near the exhaust outlet in the rack 11-near the CPU of each computer c-near the exhaust outlet in the rack 11-free access floor 15 in this order. 7 and 8 also show the length of the optical fiber 24 in each area. Here, if the length of the optical fiber 24 from the rack 11 to the next rack 11 is 1.4 m, the length of the optical fiber per rack is 16 m (= 1 + 2.1 + 0.8 + 1 + 1.2 + 7 + 1.5 + 1.4). )

  In FIG. 9, the horizontal axis represents the position in the length direction of the optical fiber, the vertical axis represents the temperature, the optical fiber is placed in an environment where the temperature is 25 ° C., and the temperature of 80 ° C. is about 5 m from the light source. It is a figure which shows measured temperature distribution at the time of applying heat so that it may become step type temperature distribution. Here, the length of the heating part is 40 cm, 1 m, 1.6 m, and 2.2 m, respectively. As can be seen from FIG. 9, when the length of the heating part is shorter than 2 m, the peak of the measured temperature distribution is observed lower than the actual temperature, and when the length of the heating part is 2 m or more, the peak of the measured temperature distribution is observed. And actual temperature almost match.

  Optical fiber temperature measurement using Raman scattering is a measurement method having only a low spatial frequency as shown in FIG. For this reason, the temperature distributions of adjacent measurement points overlap each other, and a large difference may occur between the actual temperature and the measured temperature. In the example shown in FIG. 7, since the interval between CPUs of each computer is narrow, an optical fiber is wound around each CPU to increase the temperature detection accuracy near each CPU.

  FIG. 10 shows the actual temperature distribution (set value: solid line) and the measured temperature distribution (predicted value: one-dot chain line) when the optical fiber 24 is laid as shown in FIGS. Here, a temperature distribution as shown by a solid line in FIG. 10 is set as the actual temperature distribution, and the measured temperature distribution is obtained when ideal measurement is performed by performing simulation on the actual temperature distribution.

  As estimated from the response characteristics shown in FIG. 9, in the temperature measurement using the optical fiber, the portion holding the spatial frequency characteristics of the steep temperature distribution (the vicinity of the top plate f and the rack in the rack 11 shown in FIG. 10). 11 is not able to follow the change in the vicinity of the outside ceiling e), and there is a large difference (about 4 ° C.) between the actual temperature and the measured temperature. The temperature near the top f in the rack 11 is not important for monitoring the flow of air (refrigerant), so there is no problem even if there is a large error, but the temperature near the ceiling e outside the rack 11 is used for monitoring the air flow. It is important, and if the difference between the actual temperature and the measured temperature is large, the air conditioning cooling equipment cannot be controlled properly. In order to appropriately control the air-conditioning cooling equipment, the measurement points shown in FIG. 6, that is, the vicinity of the grille a of the free access floor 15, the vicinity of the intake port b in the rack 11, the vicinity c of the CPU of each computer, the exhaust in the rack 11 The difference between the actual temperature and the measured temperature in the vicinity of the mouth d and the vicinity of the ceiling e on the outside (front side) of the rack 11 is preferably less than 2 ° C.

  11 and 12 are schematic views showing a second example (comparative example) of laying optical fibers. FIG. 11 shows the laid state of the optical fiber when the rack is viewed from the side, and FIG. 12 shows the laid state of the optical fiber when the rack is viewed from above. In FIG. 12, a thick solid line indicates an optical fiber disposed in the equipment installation area (including the inside of the rack) 10, and a thick broken line indicates an optical fiber disposed on the free access floor 15. 11 and 12 also show the length of the optical fiber in each area.

  Usually, the computer has a built-in sensor for detecting the temperature of the CPU (CPU junction temperature). In this second example, the temperature of the CPU is measured by a sensor built in the computer, and the temperature near the CPU is not measured in the optical fiber. 11 and 12, when the optical fiber 24 is laid, if the length of the optical fiber 24 from the rack 11 to the next rack 11 is 1.4 m, the optical fiber per rack Is 9.4 m (= 1 + 2.1 + 0.8 + 0.5 + 1 + 0.5 + 2.1 + 1.4).

  FIG. 13 shows an actual temperature distribution (set value: solid line) and a measured temperature distribution (predicted value: one-dot chain line) when the optical fiber 24 is laid as shown in FIGS. As can be seen from FIG. 13, even when the optical fiber 24 is laid as shown in FIGS. 11 and 12, the vicinity of the top plate f in the rack 11, the vicinity of the exhaust outlet d in the rack 11, and the vicinity of the ceiling outside the rack 11. A difference of 2 ° C. or more occurs between the actual temperature at e and the measured temperature.

  14 and 15 are schematic views showing a third example (example) of laying optical fibers. FIG. 14 shows the laid state of the optical fiber when the rack is viewed from the side, and FIG. 15 shows the laid state of the optical fiber when the rack is viewed from above. In FIG. 15, a thick solid line indicates an optical fiber disposed in the equipment installation area (including the inside of the rack) 10, and a thick broken line indicates an optical fiber disposed on the free access floor 15. 14 and 15 also show the length of the optical fiber in each area.

  In the third example, the first optical fiber 24a for measuring the temperature measurement point having a relatively low peak temperature, that is, the temperature in the vicinity of the grille a of the free access floor 15 and the vicinity of the intake port b in the rack 11 Two temperature measurement points having a relatively high peak temperature, that is, the vicinity of the CPU c in the rack 11, the vicinity of the exhaust outlet d, and the second optical fiber 24 b for measuring the temperature near the ceiling e outside the rack 11. Lay optical fiber. When laid in this way, the fiber length per rack of the first optical fiber 24a is 3.6 m (= 1 + 0.9 + 0.7), and the fiber length per rack of the second optical fiber 24b is 10 m. .4 m (= 1 + 1.2 + 0.5 + 0.7), and the total fiber length of the first and second optical fibers 24a and 24b per rack is 14 m.

  FIG. 16 is a diagram showing an actual temperature distribution (set value: solid line) and a measured temperature distribution (predicted value: one-dot chain line) when the second optical fiber 24b is laid as shown in FIGS. . As can be seen from FIG. 16, in the third example, the difference between the actual temperature and the measured temperature is 2 in any of the vicinity c of the CPU in the rack 11, the vicinity d of the exhaust port, and the vicinity e of the ceiling outside the rack 11. It is less than ℃.

  FIG. 17 is a diagram showing an actual temperature distribution (set value: solid line) and a measured temperature distribution (predicted value: one-dot chain line) when the first optical fiber 24a is laid as shown in FIGS. . As can be seen from FIG. 17, in the third example, the temperature in the vicinity of the grill a of the free access floor 15 can be accurately measured, and the temperature distribution in the vicinity of the intake port b in the rack 11 is also reproduced with good accuracy. Yes.

  That is, by laying the optical fiber as in the third example, the temperature distribution in the computer room can be detected with relatively good accuracy. As described above, since the optical fiber temperature measurement has only a low spatial frequency as described above, in the first and second examples, the error becomes large when the temperature difference between the adjacent measurement points is relatively large, whereas the third error is large. This is because the temperature difference between adjacent measurement points is made small in the example.

  Further, by laying the optical fiber as in the third example, the length of the optical fiber per rack is larger than in the case of laying the optical fiber as in the first example (see FIGS. 7 and 8). Therefore, the temperature distribution of more racks can be measured using the same length of optical fiber.

  18 and 19 are schematic views showing a fourth example (example) of laying optical fibers. FIG. 18 shows an optical fiber laying state when the rack is viewed from the side, and FIG. 19 shows an optical fiber laying state when the rack is viewed from above. 18 and 19 also show the length of the optical fiber in each area.

  In the fourth example, the temperature of the vicinity of the grille a of the free access floor 15 and the vicinity of the intake port b in the rack 11 is measured by the first optical fiber 24a as in the third example. On the other hand, the second optical fiber 24b measures the temperature of the vicinity of the ceiling e outside the rack 11 and the vicinity of the exhaust port d in the rack 11, and the temperature of the CPU is measured by a sensor built in the computer.

  If the lengths of the optical fibers 24a and 24b from the rack 11 to the next rack 11 are both 0.7 m, the length of the first optical fiber 24a per rack is 3.6 m (= 1 + 1.9 + 0. 7), and the length of the second optical fiber 24b is 5.1 m (= 1 + 0.5 + 2.4 + 0.5 + 0.7). Accordingly, in the fourth example, the total length of the first and second optical fibers 24a and 24b per rack is 8.7 m.

  FIG. 20 shows an actual temperature distribution (set value: solid line) and a measured temperature distribution (predicted value: one-dot chain line) when the second optical fiber 24b is laid as shown in FIGS. . As can be seen from FIG. 20, when the second optical fiber 24b is laid as shown in FIGS. 18 and 19, the actual temperature in the vicinity of the inlet d inside the rack 11 and in the vicinity e of the ceiling outside the rack 11 Any difference from the measured temperature is less than 2 ° C.

  Note that the actual temperature distribution and the measured temperature distribution of the first optical fiber 24a are the same as in the third example (see FIG. 17), and thus the description thereof is omitted here.

  By laying the optical fiber as in the fourth example, the length of the optical fiber per rack compared to the case of laying the optical fiber as in the second example (see FIGS. 11 and 12). Therefore, the temperature distribution of more racks can be measured using the same length of optical fiber.

  Hereinafter, an example of an optical fiber detector (temperature distribution measuring device) used in the present embodiment will be described.

  FIG. 21 is a schematic diagram illustrating an example in which temperature measurement is performed using two single-channel single-ended optical fiber detectors. In this example, one of the optical fiber detectors 51a is connected to a first optical fiber 24a that passes through a low temperature portion of each rack 11 (such as a free access floor near the grill a and an inlet near the rack b). The other optical fiber detector 51b is connected to the second optical fiber 24b passing through the high temperature portion of each rack 11 (the CPU vicinity c, the exhaust outlet vicinity d, the rack outer vicinity e, etc.) in each rack 11. Connect and measure the temperature on the high temperature side.

  FIG. 22 is a schematic diagram showing an example of temperature measurement using a two-channel single-ended optical fiber detector. In this example, a switch 53 is provided between the detector 52 and the first optical fiber 24a and the second optical fiber 24b, and the switch 52 causes the detector 52, the first optical fiber 24a, and the second optical fiber 24b to be connected. Switching between the optical fiber 24b and the optical fiber 24b is performed at a constant period, and the temperature of the high temperature portion and the low temperature portion of each rack 11 is measured.

  FIG. 23 is a schematic diagram showing an example in which temperature measurement is performed using a two-channel loop optical fiber detector. In this example, the first optical fiber 24a is laid so as to pass through the low temperature portion of each rack 11 (such as the vicinity of the grill on the free access floor and the vicinity of the air inlet b in the rack), and the second optical fiber 24b is connected to each rack. The rack 11 is laid so as to pass through high-temperature parts (the vicinity of the CPU c in the rack, the vicinity d of the exhaust port, the vicinity e of the ceiling outside the rack, etc.). Further, a switch 55 is disposed between the optical fiber detector 54 and the first optical fiber 24a and the second optical fiber 24b. The switch 55 switches between the detector 54 and the first optical fiber 24a and the second optical fiber 24b at a constant period, and measures the temperature of the high temperature portion and the low temperature portion of each rack 11.

  FIG. 24 is a schematic diagram showing an example of temperature measurement using a one-channel loop optical fiber detector. In this example, the forward path of the optical fiber 24 is laid so as to pass through the low temperature part of each rack 11 (such as the vicinity of the grill on the free access floor and the vicinity of the air inlet b in the rack). The return path of the optical fiber 24 is laid so as to pass through the vicinity of the CPU c, the vicinity of the exhaust port d, the vicinity of the ceiling e outside the rack, and the like. Thereby, the temperature of the high temperature part and the low temperature part of each rack 11 is measured with one optical fiber 24. Note that both ends of the optical fiber 24 are connected to a switcher 57, and the switcher 57 is configured to switch the input and output of laser light.

(Temperature control system)
FIG. 25 is a schematic diagram illustrating a first configuration example of a temperature control system for a computer room according to the embodiment. In the equipment installation area 10 of the computer room, a plurality of server racks 11 storing a plurality of computers (blade servers, etc.) and new jobs are distributed so that the load on each computer is equalized by monitoring the load on each computer. A load distribution server rack 61 that houses the load distribution server is arranged.

  In these racks 11 and 61, for example, optical fibers are laid as in the third example (see FIGS. 14 and 15) or the fourth example (see FIGS. 18 and 19). The optical fiber detector 73 is connected to these optical fibers, introduces laser light into the optical fiber, detects backscattered light generated in the optical fiber, and calculates the temperature distribution along the length direction of the optical fiber. Measure in real time. The result of temperature measurement by the optical fiber detector 73 is transmitted to the controller 71 in real time.

  The temperature sensor 74 is a sensor that detects the temperature of the CPU (CPU junction temperature) built in each computer stored in the racks 11 and 61. The temperature detection results by these temperature sensors 74 are also transmitted to the control unit 71 in real time.

  The control unit 71 controls the air conditioner 72 based on signals (data) input from the optical fiber detector 73 and the temperature sensor 74, and controls the exhaust fan 63 provided in each server rack 11, 61. Or a grill adjusting mechanism for adjusting the opening width of the grill 41 (or a cooling fan provided in the grill 41). Hereinafter, the air conditioner 72, the exhaust fan 63, the grill adjusting mechanism, and the like are collectively referred to as an air conditioning cooling facility.

  FIG. 26 is a conceptual diagram showing the concept of the temperature control method in the system described above. The controller 71 receives the temperature measurement result by the optical fiber detector 73 and the CPU temperature measurement result by the temperature sensor 74. Further, the CPU 71 and the target temperature in the computer room rack, the vicinity of the ceiling, the free access floor, and the like are input to the control unit 71. The target temperature is a temperature that is equal to or lower than the temperature set based on the specifications of the CPU or the like, and is set so that the sum of the power consumption of the air conditioning cooling facility and the power consumption of all racks is minimized.

  The control unit 71 compares the temperature distribution in the computer room measured by the optical fiber detector 73 and the detected value of the CPU temperature by the temperature sensor 74 with the target temperature, and various air conditioning cooling facilities in the computer room, that is, air conditioners. 72, the grill adjusting mechanism and the exhaust fans 63 of the racks 11 and 61 are controlled. Thereby, the temperature distribution in the computer room changes. The change is measured in real time by the optical fiber detector 73 and transmitted (feedback) to the control unit 71. Further, the CPU temperature of the computers stored in the racks 11 and 61 changes due to the change in the temperature distribution of the computer room. This change in CPU temperature is also detected in real time by the temperature sensor 74 and transmitted (feedback) to the control unit 71.

  In this way, the control unit 71 controls the air conditioning cooling equipment (the air conditioner 72, the grill adjustment mechanism, the exhaust fan 63 of each rack 11, 61, etc.) so that the temperature of each part in the computer room becomes the target temperature. .

  In this embodiment, the temperature distribution in the computer room is measured in real time by the optical fiber detector 73 and the temperature sensor 74, and based on the result, the controller 71 controls the air conditioner 72, the grill adjustment mechanism, and the racks 11 and 61. The air-conditioning cooling equipment such as the exhaust fan 63 is controlled to prevent the accumulation of heat, and there are no places that are cooled more than necessary. As a result, it is possible to suppress power consumption required for cooling the computer room.

  FIG. 27 is a schematic diagram illustrating a second configuration example of a temperature control system for a computer room according to the embodiment. In FIG. 27, the same components as those in FIG. 25 are denoted by the same reference numerals, and detailed description thereof is omitted.

  When a new job is input to the load balancing server stored in the load balancing server rack 61, the load balancing server determines a computer to process the new job according to the calculation amount of the new job and the operating state of each computer. To do. In addition, the load distribution server transmits information indicating the calculation amount of the new job and information indicating the computer that processes the new job to the state variable storage unit 75.

  The state variable storage unit 75 includes a calculation amount of a job processed in the past, a change in CPU temperature of the computer that processed the job, and an air conditioning cooling facility control parameter for setting the CPU temperature of the computer that processed the job as a target value. Information such as the opening degree of the grill opening and the rotational speed of the exhaust fan is stored as a database.

  The state variable storage unit 75 compares the calculation amount of the new job sent from the load balancing server with the calculation amount of the previous equivalent job stored in the database, and determines the CPU temperature of the computer that processes the job. Information such as air conditioning cooling equipment control parameters for setting the target value is extracted from the database and output to the control unit 71.

  Based on the target temperature, the information input from the state variable storage unit 75, the information input from the optical fiber detector 73, and the information input from the temperature sensor 74, the control unit 71 Various air-conditioning cooling facilities, that is, the air conditioner 72, the grill adjusting mechanism, and the exhaust fans 63 of the racks 11 and 61 are controlled.

  FIG. 28 is a conceptual diagram showing the concept of the temperature control method in the system described above.

  The control unit 71 and the state variable storage unit 75 are input with the allowable temperature of the CPU and the target temperature in the rack of the computer room, near the ceiling, the free access floor, and the like. Further, the temperature distribution measured by the optical fiber detector 73 is input to the control unit 71 and the state variable storage unit 75 in real time, and the CPU temperature of each computer measured by the temperature sensor 74 is input in real time. .

  Information relating to the new job and information on the computer that processes the new job are input to the state variable storage unit 75 from the load balancing server in the load balancing server rack 61. When these pieces of information are input, the state variable storage unit 75 compares the calculation amount of the new job with the stored database information, and sets the CPU temperature of the computer that processes the new job to the target value. Necessary control parameters of the air conditioning cooling equipment are extracted from the database and output to the control unit 71.

  The control unit 71 controls the air conditioning and cooling equipment based on the control parameters input from the state variable storage unit 75, the temperature distribution measurement result by the optical fiber detector 73, and the CPU temperature measurement result of each computer by the temperature sensor 74. To do. In this case, the control unit 71 controls the exhaust fan 63 of the rack containing the computer that processes the new job, the grill adjustment mechanism in the vicinity of the rack, and the like so as to suppress the heat generation of the CPU accompanying the processing of the new job.

  In this embodiment, since the computer controls the exhaust fan, the grill adjustment mechanism, and the like of the rack in which the computer is stored before (or at the same time as) the actual processing of the new job, the CPU temperature rises. Can be suppressed. Generally, when the CPU generates heat, the leakage current increases and the power consumption increases. In the present embodiment, the CPU that is expected to generate heat is specified in advance based on information from the load balancing server, and the amount of heat generated by the CPU is predicted. Therefore, it is possible to control the air conditioning and cooling equipment so as to suppress the heat generation of the CPU. Is possible. In other words, in the present embodiment, the heat generation of the CPU of the computer that processes the new job is controlled by controlling the cooling control by so-called feedforward control, thereby avoiding the increase in power consumption accompanying the heat generation of the CPU. As a result, the power consumed in the computer room is reduced.

  FIG. 29 is a schematic diagram showing an example in which the above-described technique is applied to a hybrid cooling method combining water cooling and air cooling. Here, three racks 11 arranged adjacent to each other are taken as one set, and a pipe 77a for supplying cooling water (cooling medium) from the chiller 76 via the free access floor 10 and cooling water supply for each set. A pump 78 and a pipe 77b for returning the cooling water after heat exchange to the chiller 76 via the free access floor 15 are provided.

  The second optical fiber 24b is laid so as to pass through the high-temperature portions of each rack 11 (the CPU vicinity c in the rack, the exhaust outlet vicinity d, the ceiling vicinity e outside the rack, etc .: see FIG. 6). On the other hand, the first optical fiber 24a is laid so as to pass through the low temperature portion of each rack 11 (the vicinity of the grille a of the free access floor 15, the vicinity of the inlet port b in the rack, etc .: see FIG. 6). However, as shown in FIG. 29, the first optical fiber 24a is wound around the pipe 77a by a predetermined length (for example, 1 to 4 m) before being introduced into the rack 11 for each group. Is wound around the pipe 77b by a predetermined length.

  The first optical fiber detector 73a is connected to the first optical fiber 24a, and the second optical fiber detector 73b is connected to the second optical fiber 24b. Based on the temperature distribution in the computer room detected by the optical fiber detectors 73a and 73b, the controller 71 controls the air conditioners 72 and the racks 11 so that the temperature of each part in the computer room becomes the target temperature. The exhaust fan 61, the cooling water supply pump 78, the grill adjusting mechanism and the like (see FIG. 25) are controlled.

  In the present embodiment, the first optical fiber 24a is wound around the pipes 77a and 77b through which the cooling water passes. The pipes 77a and 77b through which the cooling water passes have a relatively small temperature change, and the optical fiber 24a is wound by a predetermined length, so that the temperature of this portion can be accurately measured. By correcting the temperature measurement value of the other part on the basis of the temperature measurement value of this part, the temperature measurement accuracy of the other part can be further improved.

  In the present embodiment, two systems of temperature distribution measurement systems using optical fibers (the first optical fiber 24a and the first optical fiber detector 73a, and the second optical fiber 24b and the second optical fiber detector 73b) are used. Therefore, even if one temperature distribution measurement system cannot be used due to failure or maintenance, it is necessary to widen the margin, but only the other temperature distribution measurement system can measure the temperature distribution and operate the system. Is possible. Thereby, continuous operation of the system is possible.

  Furthermore, in this embodiment, since the temperature of the cooling water before being introduced into the rack 11 by the first optical fiber 24a and the temperature of the cooling water discharged from the rack 11 are known, the amount of heat exchanged in the rack 11 Can be grasped. Further, by controlling the cooling water supply amount by the cooling water supply pump 78 by the control unit 71, the temperature of each part in the computer room can be adjusted in more detail.

(Air volume measurement)
In order to properly operate the air conditioner in the computer room, it is important not only to measure the temperature of air discharged from each rack but also to know the amount of air discharged from each rack. Although it is conceivable to estimate the amount of air discharged (or the amount of air taken into the rack) from the number of rotations of the fans, usually a single rack is equipped with multiple fans. It is difficult to accurately determine the amount of air discharged.

  Thus, for example, an anemometer may be arranged at the intake or exhaust port of the rack to measure the wind speed and calculate the air volume per unit time from the wind speed and the area of the intake or exhaust port. In this case, it is necessary to avoid disturbing the flow of air flowing through the intake port or the exhaust port as much as possible.

  Thermal wind sensors, ultrasonic wind sensors, vane wheel wind sensors, etc. are commercially available as ultra-compact wind sensors, and by using these wind sensors, the flow of air that flows through the intake or exhaust port The wind speed can be measured with almost no disturbance. However, any of these wind speed sensors measures the wind speed at the place (point) where the sensor is disposed, and does not measure the average wind speed of the air flowing through the intake port or the exhaust port. Hereinafter, an ultra-compact wind speed sensor that detects the wind speed at a place (point) installed as described above is referred to as a point measurement type wind speed sensor.

  In the method of calculating the air volume discharged from the rack by measuring the air speed flowing through the intake or exhaust port, the measurement accuracy of the air volume depends on the measurement accuracy of the average wind speed of the air flowing through the intake or exhaust port. To do. Therefore, it is conceivable that a large number of point measurement type wind speed sensors are attached to the intake port or the exhaust port, and the average value of the wind speed measured by these sensors is calculated to improve the measurement accuracy of the average wind speed. In this case, however, the measurement accuracy of the average wind speed increases as the number of sensors increases, but there is a problem that the cost required for sensor installation and maintenance management increases.

  FIG. 30 is a schematic diagram showing an air volume measuring device and an air volume measuring method according to the present embodiment. In the present embodiment, optical fibers 81 a and 81 b are laid on the intake side and the exhaust side of the rack 11 in which an electronic device (computer, storage, etc.) 83 is housed, and these optical fibers 81 a and 81 b are connected to the optical fiber detector 91. To do. The optical fiber detector 91 has the same structure as the temperature distribution measuring apparatus shown in FIG. 2, and measures the average temperature of the air on the intake side and the exhaust side of the rack 11 in which the optical fibers 81a and 81b are laid in almost real time. Then, the data is output to the calculation unit 90.

  On the other hand, the power detection unit 92 detects the total power consumption of the electronic devices 83 in the rack 11 almost in real time and outputs the detected power to the calculation unit 90. The calculation unit 90 calculates the amount of air discharged from the rack 11 based on the average air temperature on the intake and exhaust sides of the rack 11 detected by the optical fiber detector 91 and the power consumption detected by the power detection unit 92 ( Detect air volume).

  When the electronic device 83 in the rack 11 is in operation, the air passing through the exhaust port of the rack 11 (hereinafter referred to as exhaust side air) is higher than the average temperature of the air passing through the intake port of the rack 11 (hereinafter referred to as intake side air). ) The average temperature is higher. The difference between the average temperature of the intake air and the average temperature of the exhaust air is related to the amount of heat generated by the electronic device 83 in the rack 11 and the amount of air passing through the rack 11.

The amount of heat generated by the electronic device 83 in the rack 11 is Q (kcal / min), the amount of air discharged from the rack 11 (air volume) is U (m ³ / min), and the average temperature and exhaust air of the intake side air If the temperature difference from the average temperature of the side air is ΔT (° C.), there is a relationship represented by the following equation (2).

Q = U × C × ΔT (2)
Here, C is a constant, and the specific volume of air is 0.24 (kcal / kg / ° C.) and the specific volume of standard air (temperature is 20 ° C., air at 1 atmosphere (760 mmHg)) is 0.83 (m ³ / kg). ), That is, 0.29 (kcal / m ³ / ° C.) can be used.

  The amount of heat Q can be obtained from the following equation (3) by measuring the total power consumption P (kW) of the electronic device 83 housed in the rack 11.

Q = P × 60 / 4.19 (3)
Therefore, the amount U of air discharged from the rack 11 can be obtained by the following equation (4).

U = P × 60 / (ΔT × 4.19 × 0.29) (4)
That is, if the difference ΔT between the average temperature of the intake-side air and the average temperature of the exhaust-side air and the total power consumption P of the electronic device 83 housed in the rack 11 are known, the amount of air discharged from the rack 11 (Air volume) can be calculated. As the power detection unit 92 that detects the total power consumption P of the electronic device 83, for example, various commercially available power meters can be used.

  As described above, in the present embodiment, the optical fibers 81 a and 81 b are laid on the intake side and the exhaust side of the rack 11, respectively, and these optical fibers 81 a and 81 b are connected to the optical fiber detector 91, thereby Measure the temperature distribution on the side and exhaust side.

  The temperature distribution measurement by the optical fiber has a low-pass characteristic, and when the temperature changes sharply as shown in FIG. 9, that is, when the actual temperature distribution includes a high frequency component, the peak of the measured temperature distribution is Lower and widen. However, the integrated value of the measured temperature distribution and the integrated value of the actual temperature distribution have a proportional relationship. If the relationship between the integrated value of the measured temperature distribution and the integrated value of the actual temperature distribution is examined in advance, the measured temperature distribution The average temperature of the intake air and the exhaust air can be calculated from the integrated value of the distribution.

  In addition, in order to obtain the average temperature of the intake side air and the exhaust side air, for example, a plurality of point measurement type temperature sensors are attached to the intake port and the exhaust port of the rack, respectively, and the temperature measured by these point measurement type temperature sensors is measured. It is conceivable to calculate the average to obtain the average temperature. Here, the point measurement type temperature sensor refers to a sensor that detects the temperature of a place (point) installed like a thermocouple, for example.

  When the average temperature is detected by a point measurement type temperature sensor, if the accuracy of the average temperature is to be increased, the number of sensors increases, and the cost required for sensor installation and maintenance management increases. On the other hand, in the temperature distribution measurement using an optical fiber, it is considered that an infinite number of temperature sensors are installed along the length direction of the optical fiber in order to detect the temperature of the entire optical fiber arranged in the measurement region. it can.

  In other words, the optical fiber temperature distribution measuring apparatus can measure the average temperature with the same or higher accuracy as that measured using a number of point measurement type temperature sensors. As a result, the amount of air discharged from the rack (air volume) can be measured with good accuracy, and the operating state of the air conditioner in the computer room can be appropriately controlled based on the measurement result. Further, by dividing (dividing) the amount of air discharged from the rack by the area of the intake port or the exhaust port, the wind speed at the intake port or the exhaust port can be obtained.

  Hereinafter, the air volume measuring method (example) according to the present embodiment will be described in more detail in comparison with a comparative example.

  As an example, as shown in FIG. 31, an optical fiber 81 is laid on the intake side and the exhaust side of a rack 11 in which electronic equipment (not shown) is housed, and the temperature distribution is measured. In the example shown in FIG. 31, the optical fiber 81 is introduced into the rack 11 from the free access floor 15 and laid so as to return to the free access floor 15 through a predetermined measurement point in the rack 11. The measurement points are set so that not only the temperature distribution in the height direction of the rack 11 but also the temperature distribution in the width direction can be measured. Here, the interval between the measurement points adjacent to each other is 0.25 m. The circles in FIG. 31 indicate the positions of the measurement points, and each measurement point is numbered along the length direction of the optical fiber 81.

  That is, the measurement point in the free access floor 15 immediately before being introduced into the rack 11 is derived from No. 0, the first measurement point of the optical fiber 81 introduced into the rack 11 is derived from No. 1,. Each measurement point is numbered such that the measurement point immediately before the measurement is No. 21 and the measurement point immediately after being introduced from the rack 11 to the free access floor is No. 22. The measurement points in the rack 11 are 21 points from No. 1 to No. 21.

  Note that measurement points are set for every 0.25 m in the optical fiber 81 (optical fiber disposed in the free access floor 15) before being introduced into the rack 11 and after being led out from the rack 11. Further, it is assumed that the temperature in the free access floor 15 is maintained at 20.5 ° C.

  On the other hand, as a comparative example, as shown in FIG. 32, thermocouples (point measurement type temperature sensors) 85 are installed at measurement points on the intake side and the exhaust side of the rack 11 in which electronic devices (not shown) are housed. Measure the temperature distribution on the side and exhaust side. In FIG. 33, the example of the temperature of each measurement point measured with the thermocouple 85 is shown.

  FIG. 34 is a diagram showing the result of simulating the measured temperature distribution on the intake side measured with the optical fiber and thermocouple, with the horizontal axis representing the position in the length direction of the optical fiber and the vertical axis representing the measured temperature. . FIG. 35 is a diagram showing the result of simulating the measured temperature distribution on the exhaust side measured with the optical fiber and thermocouple, with the horizontal axis representing the position in the length direction of the optical fiber and the vertical axis representing the measured temperature. It is. 34 and 35, the position of 2.25 m of the optical fiber 81 corresponds to the measurement point No. 0, the position of 2.5 m corresponds to the measurement point No. 1, and the position of 7.5 m is measured. Corresponds to point No.21. 34 and 35, the position of the temperature distribution measurement point by the thermocouple 85 is associated with the temperature distribution measurement point by the optical fiber 81 for convenience. For example, the temperature measured by the thermocouple 85 arranged at the No. 1 measurement point in FIG. 32 is reflected in the temperatures at 2.5 m, 3.5 m, and 7.5 m.

  As shown in FIG. 34, on the intake side where the temperature difference between the measurement points is small, the temperature distribution measured by the optical fiber and the temperature distribution measured by the thermocouple substantially coincide. On the other hand, on the exhaust side where the temperature difference between the measurement points becomes large, the temperature distribution measured with the optical fiber is measured points No. 1 (2.5 m) and No. 21 (7.5 m) as shown in FIG. ) Greatly spread to the outside. How much the temperature distribution spreads with respect to the peak temperature depends on the characteristics of the optical fiber temperature measuring device (optical fiber 81 and optical fiber detector 91). Conversely, if the characteristics of the optical fiber temperature distribution measuring device are examined in advance, it is possible to know how much the temperature distribution spreads with respect to the peak temperature.

  Here, it is assumed that the temperature distribution measured by the optical fiber spreads to a position of 0.25 m on the minus side and spreads to a position of 9.75 m on the plus side as shown in FIG. That is, when calculating the integral value of the temperature distribution, the integration range is from the position of 0.25 m to the position of 9.75 m. The number of measurement points during this period is 39. When obtaining the average temperature, the measurement values of these 39 measurement points are integrated and divided (divided) by the number of measurement points in the rack 11 (ie, 21).

  As described above, it is known that the integral value of the measured temperature distribution is proportional to the integral value of the actual temperature distribution, but the proportionality constant depends on the characteristics of the optical fiber and optical fiber detector optical fiber temperature distribution measuring device. Dependent. Therefore, in order to calculate the average temperature, it is also necessary to experimentally obtain a proportionality constant in advance. Here, the value of the proportionality constant is 1.03.

When obtaining the average temperature from the temperature measured by the thermocouple 85, simply add the measured values from each thermocouple 85 arranged on the intake side (or exhaust side) of the rack 11 and divide by the number of measurement points. Good. For example, when the temperatures of the measurement points from No. 1 to No. 11 in FIG. 32 are T ₁ , T ₂ ,..., T ₁₁ , the average temperature T _ave is T _ave = (T ₁ + T ₂ +... + T ₁₁ ). / 11. In addition, when calculating the average temperature T _ave with the measured values of three measurement points (No. 2, No. 6, No. 10) on the center line of the rack 11 (indicated by a one-dot chain line in FIG. 32), T _ave = (T ₂ + T ₆ + T ₁₀ ) / 3.

On the other hand, when obtaining the average temperature T _ave from the temperature distribution measured by the optical fiber, T ₁ the temperature of 39 measurement points from the position of 0.25m to the position of 9.75m, T _2, ..., and T ₃₉ When the temperature of the free access floor (reference temperature) is Tc, the following equation (5) is obtained.

T _ave = ((T ₁ −Tc) + (T ₂ −Tc) +... + (T ₃₉ −Tc)) × (1 / 1.03) × (1/21) + Tc (5)
36 shows the average temperature obtained by the optical fiber temperature distribution measuring device, the average temperature obtained by the three thermocouples 85 arranged at the measurement points No. 2, No. 6, and No. 10, from No. 1. The average temperature calculated | required with 11 thermocouples arrange | positioned at the measurement points to No. 11 is shown.

Further, the total power consumption of the electronic device 83 housed in the rack 11 is 3.8 kW, the air volume obtained using the above-described equation (4), and the intake and exhaust air of the rack 11 calculated using the air volume. FIG. 36 shows the wind speed at the mouth. Note that the wind speed is obtained by setting the area of the intake port and the exhaust port of the rack 11 to 0.40 m ² .

  As can be seen from FIG. 36, on the intake side where the variation in temperature distribution is relatively small, the average temperature measured using an optical fiber, the average temperature measured using three thermocouples, and 11 thermocouples. This is almost the same as the average temperature measured using. However, on the exhaust side where the variation in temperature distribution is large, the average temperature measured using an optical fiber and the average temperature measured using 11 thermocouples are almost the same, but three thermocouples are used. The average temperature measured in this way is greatly different from the average temperature measured by other methods. Therefore, the air volume and the wind speed calculated using the average temperatures are almost the same between the case where the measurement is performed using the optical fiber and the case where the measurement is performed using the 11 optical fibers, and three thermocouples are used. The value when measured by this method is greatly different from the value measured by other methods.

  From the above, it was confirmed that the method using the optical fiber can measure the air volume and the wind speed with the same or higher accuracy than the method using many point measurement type temperature sensors.

  In the above-described example, the case where the amount of air discharged from the rack (air volume) and the wind speed at the intake port or the exhaust port is measured has been described. Can be used to measure quantity or wind speed.

  In the above-described example, the optical fibers are laid in the same way on the intake side and the exhaust side. However, the laying of optical fibers may be changed between the intake side and the exhaust side. For example, since the temperature difference due to the position of the measurement point is small on the intake side, it is considered that the air flow measurement accuracy hardly deteriorates even if the laying of the optical fiber is simplified.

(Measurement method of calorific value)
FIG. 37 is a schematic diagram illustrating a calorific value measuring device and a calorific value measuring method according to the embodiment. 37, the same components as those in FIG. 30 are denoted by the same reference numerals.

  In the present embodiment, temperature measuring optical fibers 101a and 101b are laid on the intake side and the exhaust side of a rack 11 in which an electronic device (computer, storage, etc.) 83 is housed, and these optical fibers 101a and 101b are optical fiber detectors. 111 is connected. In addition, an optical fiber 102 for measuring wind speed (air flow velocity) is laid on at least one of the intake side and the exhaust side of the rack 11 (only the intake side in FIG. 37), and the optical fiber 102 for measuring wind speed is also an optical fiber detector 111. Connect to.

  The optical fiber detector 111 basically has the same structure as the temperature distribution measuring apparatus shown in FIG. 2, and supplies laser pulses to the temperature measuring optical fibers 101a and 101b. Then, the optical fiber detector 111 detects the backscattered light generated in the optical fibers 101a and 101b, calculates the average temperature on the intake side and the exhaust side of the rack 11 based on the detection result, and sends it to the calculation unit 112. Output.

  The wind speed measuring optical fiber 102 is formed of an optical fiber and a heating element (heating wire) disposed in the vicinity thereof. For example, Patent Documents 6 and 7 describe devices that detect a fluid velocity by arranging a heating element in the vicinity of an optical fiber. In the present embodiment, the wind speed measuring optical fiber 102 is one in which a heating wire is wound around a predetermined portion of the optical fiber. The wind speed measuring optical fiber 102 may be formed by a heating element formed in a pipe shape and an optical fiber inserted through the heating element.

  The optical fiber detector 111 also supplies a laser pulse to the wind speed measuring optical fiber 102 and detects the temperature in the vicinity of the heating element by backscattered light generated in the optical fiber. The optical fiber detector 111 stores in advance the relationship between the wind speed and temperature obtained through experiments and the like, and converts the temperature in the vicinity of the heating element into the wind speed and outputs it to the computing unit 112.

  The computing unit 112 is an electronic device housed in the rack 11 based on the average temperature on the intake side and exhaust side of the rack 11 obtained from the optical fiber detector 111 and the average flow velocity of air on the intake side (or exhaust side). The calorific value (total calorific value) from 83 etc. is calculated and output to a display device (not shown) or the like.

The amount of heat generated in the rack 11 is Q (kcal / min), the average wind speed on the intake side is F _in (m / min), the average wind speed on the exhaust side is F _out (m / min), and the average temperature on the intake side is T _in (° C.), the exhaust side average temperature is T _out (° C.), the intake side opening area is A _in (m ² ), and the exhaust side opening area is A _out (m ² ). The following equation (6) holds.

_{Q = C (F out · A} out) × (T out -T in) = C (F in · A in) × (T out -T in) ... (6)
However, C is a constant.

  In the present embodiment, the amount of heat generated in the rack 11 can be accurately measured in real time based on the average temperature on the intake side and exhaust side of the rack 11 and the average wind speed on the intake side or exhaust side of the rack 11. it can.

  Instead of the wind speed measuring optical fiber 102, it is conceivable to use the above-described point measurement type wind speed sensor. However, in that case, if the number of sensors is small, the measurement accuracy is low, and if the number of sensors is large, there is a problem that the cost required for sensor installation and maintenance management increases. By measuring the wind speed using an optical fiber as in this embodiment, the average wind speed on the intake side or the exhaust side of the rack 11 can be measured with high accuracy, and as a result, the measurement accuracy of the calorific value is increased.

  In the above-described example, the case where the amount of heat generated in the rack 11 in which the electronic device 83 is housed is described, but the disclosed technique occurs in a container other than the rack (a container provided with an intake port and an exhaust port). You may use for the measurement of calorie.

  DESCRIPTION OF SYMBOLS 10 ... Equipment installation area 11, 61 ... Rack, 12, 41, 62 ... Grill (vent), 15 ... Free access floor, 16 ... Cable, 17 ... Cable duct, 19, 72 ... Air conditioner, 21 ... Laser light source 22a, 22b ... lens, 23, 31a, 31b, 31c ... beam splitter, 24, 24a, 24b81, 81a, 81b ... optical fiber, 25 ... wavelength separator, 26 ... photodetector, 26a, 226b, 26c ... light reception Part, 33a, 33b, 33c ... optical filter, 34a, 34b, 34c ... condensing lens, 51a, 51b, 52, 54, 56, 73, 91 ... optical fiber detector, 53, 55, 57 ... switch, 63 ... exhaust fan, 71 ... control unit, 74 ... temperature sensor, 75 ... state variable storage unit, 85 ... thermocouple, 90 ... calculation unit, 92 ... power detection unit, 101a 101b ... Temperature measuring optical fiber, 102 ... wind velocity measuring optical fiber, 111 ... optical fiber detector, 112 ... arithmetic unit.

Claims (7)

In the temperature measurement method of a computer room in which multiple racks for storing multiple computers or storage are installed,
Laying a first optical fiber so as to pass through a plurality of first temperature measurement points set on at least one of the inside and the outside of the plurality of racks;
Laying a second optical fiber so as to pass through a plurality of second temperature measurement points that are set on at least one of the inside and the outside of the plurality of racks and have a peak temperature higher than the first temperature measurement point;
Temperature distribution along the length direction of the first optical fiber and the second optical fiber by introducing laser light into the first optical fiber and the second optical fiber, respectively, detecting backscattered light A temperature measurement method for a computer room characterized by measuring the temperature. In a computer room temperature control system in which multiple racks for storing multiple computers or storage are installed,
A control unit in which a target temperature of a measurement point set in the computer room is set;
An optical fiber detector for measuring the temperature of the measurement point by an optical fiber laid in the computer room;
Air conditioning cooling equipment installed in the computer room,
The temperature control system, wherein the control unit controls the air conditioning cooling equipment so that a temperature of the measurement point measured by the optical fiber detector becomes the target temperature. In a computer room temperature control system with multiple racks for storing multiple computers,
A control unit in which a target temperature of a measurement point set in the computer room is set;
An optical fiber detector for measuring the temperature of the measurement point by an optical fiber laid in the computer room;
A load balancing server that determines a computer that processes the new job in accordance with the calculation amount of the new job;
A database that stores a relationship between a calculation amount and a CPU (Central Processing Unit) temperature, and a state variable storage unit that outputs a signal corresponding to the calculation amount of the new job to the control unit using the database; ,
The control unit controls air-conditioning cooling equipment provided in the computer room according to the target temperature, a temperature measurement result by the optical fiber detector, and the signal output from the state variable storage unit. A temperature control system featuring.   The temperature control according to claim 3, wherein the control unit controls the air-conditioning cooling facility according to the signal before or at the same time as the computer starts processing the new job. system.   A first optical fiber laid so that the optical fiber passes through a plurality of first temperature measurement points set on at least one of the inside and the outside of the plurality of racks; and the inside of the plurality of racks And a second optical fiber laid so as to pass through a plurality of second temperature measurement points that are set to at least one of the outer sides and have a peak temperature higher than that of the first temperature measurement point. The temperature control system according to claim 3. An optical fiber laid on each of the intake and exhaust ports of a container having an intake port and an exhaust port and containing a heating element therein;
An optical fiber detector that introduces laser light into the optical fiber, detects backscattered light, and measures an average temperature at the intake and exhaust ports;
A calculation unit that calculates an amount of air flowing through the intake and exhaust ports from a difference in average temperature between the intake and exhaust ports detected by the optical fiber detector and a heat generation amount of the heating element. The air volume measuring device characterized by this. An optical fiber for temperature measurement laid on each of the intake and exhaust ports of a container having an intake port and an exhaust port and containing a heating element therein;
An optical fiber for wind speed measurement that is laid at the inlet or the outlet of the container and measures the average flow velocity of air;
Laser light is introduced into the temperature measuring optical fiber and the wind speed measuring optical fiber, and backscattered light is detected to measure the average temperature of the inlet and outlet of the container. A photodetector for measuring the average air flow velocity at the mouth;
A calculation unit that calculates a calorific value of the heating element from a difference in average temperature at the intake port and the exhaust port detected by the photodetector and an average flow velocity of air at the intake port or the exhaust port of the container. A calorific value measuring device.

Images