JP5482122B2 - Control method in heating system - Google Patents

Description

  The present invention relates to a control method in a heating system, and more particularly, to a method for updating an initial value when starting a heating system.

  The heat pump water heater controls the flow rate of hot water that flows through the heat pump, the incoming pipe that supplies hot water (hot water or water) to the heat pump, the outgoing pipe that delivers hot water heated by the heat pump, and the incoming and outgoing pipes. And a tank device to which hot water is supplied through a hot water supply pipe.

  The pump device has a motor for controlling the flow rate of hot water, and the rotational speed of the motor is controlled to control the flow rate of hot water. The rotational speed and the flow rate of hot water have a positive correlation. The inclination of the flow rate of hot water relative to the rotational speed depends on the pressure loss of the incoming and outgoing pipes, and the larger the pressure loss, the smaller the flow rate relative to the rotational speed. The pressure loss of the pipe here represents an amount by which the pressure of the fluid is reduced as the fluid flows in the pipe. The pressure loss increases as the length of the pipe increases, as the diameter of the pipe decreases, and as the amount of scale attached to the pipe increases.

  The pressure loss of the incoming water piping and the outgoing hot water piping differs depending on the installation environment in which the heat pump hot water supply device is installed. This is because the piping length / diameter of the incoming water piping and hot water piping and the adhesion state of the scale differ depending on the installation environment.

  At the time of starting the heat pump hot water supply device, for example, the pump device is controlled based on a predetermined rotation speed initial value. However, if the pressure loss is large with respect to the predetermined initial value of the rotational speed, the flow rate is insufficient.

  In Patent Document 1, in order to prevent a situation where the pressure loss is large and the flow rate is insufficient, a pipe length setting unit is provided in the heat pump hot water supply device, and an operator inputs the pipe length to the pipe length setting unit. If the pipe length input to the pipe length setting means exceeds the reference value, control is performed to increase the flow rate.

  Patent Documents 2 to 6 are disclosed as techniques related to the present invention.

JP 2008-259592 A JP 2007-327725 A JP 2004-301186 A Japanese Patent Laid-Open No. 2005-140439 JP 2006-266596 A JP 2003-130447 A

  However, in the technique described in Patent Document 1, since it is necessary for the worker to input the length of the pipe, the burden on the worker is caused and there is a possibility of an input error.

  Therefore, the present invention provides a control method for a heating system that can set an appropriate initial value according to pressure loss.

  A first aspect of the control method in the heating system according to the present invention includes a pump device (3) that drives the hot water to flow into the incoming water pipe and the outgoing hot water pipe connected thereto, and the incoming water pipe (h1) coupled with the control of the pump device In the heating system comprising a heating device (1) that heats the hot water flowing in through the hot water and supplies the hot water to the hot water supply pipe (h2), a predetermined amount of heat is supplied to the hot water. When the rotational speed of the pump device is controlled, the rotational speed when the rotational speed of the pump device is in a steady state is detected, and the rotational speed is greater than a reference value set based on the predetermined value Then, the initial value for the rotation speed at the next operation is increased and updated.

A second aspect of the control method in the heating system according to the present invention is the control method in the heating system according to the first aspect, wherein the rotational speed when the rotational speed of the pump device is in a steady state is when smaller than the reference value is updated to reduce the pre-Symbol Initial value.

  In a third aspect of the control method in the heating system according to the present invention, the control method in the heating system according to claim 1 or 2 is repeatedly executed every predetermined period.

  According to the first aspect of the control method in the heating system of the present invention, it can be inferred that the pressure loss of the incoming water piping and the outgoing hot water piping is large due to the rotational speed being larger than the reference value. Therefore, it can be made to operate at an initial value for an appropriate rotation speed according to the pressure loss, and even if the pressure loss is large, a shortage of flow rate can be suppressed.

  According to the second aspect of the control method in the heating system according to the present invention, it can be inferred that the pressure loss of the incoming water piping and the outgoing hot water piping is small due to the rotational speed being smaller than the reference value, and according to the pressure loss. It can be operated with an initial value for a suitable rotational speed.

  According to the 3rd aspect of the control method in the heating system concerning this invention, it can respond also to the influence by time-dependent deterioration (for example, adhesion of a scale) of a water intake piping and a hot water supply piping regularly.

It is a figure which shows the notional structure of a heating system. It is a figure which shows the relationship between a driving speed and the flow volume of hot water. It is a flowchart which shows the process of a control part. It is a flowchart which shows the process of a control part.

First embodiment.
<Configuration>
As shown in FIG. 1, this heating system includes a heating device 1, a water inlet pipe h1, and a hot water outlet pipe h2.

  The pump device 3 is provided on the water inlet pipe h1 or the hot water outlet pipe h2. The water inlet pipe h1 and the hot water outlet pipe h2 are connected to each other via the heating device 1. The pump device 3 drives the hot water to flow through the inlet pipe h1 and the outlet pipe h2 at a controllable flow rate. The pump device has an electric motor as a drive mechanism. The flow rate of the hot water is controlled by the rotational drive of the electric motor. The rotational speed of the electric motor and the flow rate of hot water have a positive correlation.

  The heating device 1 heats the low-temperature hot water that enters from the water inlet pipe h1 with the amount of heat. And the heating apparatus 1 discharges the hot hot water after a heating to the hot water piping h2. The amount of heat given to the hot water by the heating device 1 is controlled by the control unit 4.

  In the illustration of FIG. 1, a heat pump unit is shown as the heating device 1. The heating device 1 is not limited to a heat pump unit, and may be a device that heats by fire (for example, gas fire) or another device that heats by electricity.

  A heat pump unit as an example of the heating device 1 includes heat exchangers 11 and 12, a compressor 13, an expansion valve 14, a fan 15, and a refrigerant pipe 16. The heat exchangers 11, 12, the compressor 13, and the expansion valve 14 are provided on a closed loop refrigerant pipe 16.

  The compressor 13 compresses the refrigerant flowing through the refrigerant pipe 16 at a controllable compression ratio. The compression ratio at which the compressor 13 compresses the refrigerant is controlled by the control unit 4. The compressed refrigerant is sent to the heat exchanger 11 and condensed in the heat exchanger 11. That is, the heat exchanger 11 functions as a condenser. The heat exchanger 11 is connected to a water inlet pipe h1 and a hot water outlet pipe h2. The heat released by the condensation of the refrigerant is given to the hot water flowing in the heat exchanger 11 from the water inlet pipe h1 to the hot water outlet pipe h2.

  The refrigerant condensed in the heat exchanger 11 is sent to the heat exchanger 12 via the expansion valve 14. The expansion valve 14 is an electromagnetic valve that controls the flow rate of the refrigerant with a controllable opening. As the opening degree of the expansion valve 14 is increased, the flow rate of the refrigerant can be increased. The opening degree of the expansion valve 14 is controlled by the control unit 4.

  The refrigerant that has passed through the expansion valve 14 evaporates in the heat exchanger 12. That is, the heat exchanger 12 functions as an evaporator. The heat absorbed by the refrigerant as it evaporates is obtained from outside air (hereinafter also referred to as outside air).

  The refrigerant evaporated in the heat exchanger 12 is sent again to the compressor 13 and circulates through the above-described components.

  The fan 15 flows air to the heat exchanger 12 to promote heat exchange between the refrigerant and the air. The rotation speed of the fan 15 may be constant or may be variably controlled by the control unit 4.

  In such a heating apparatus 1, for example, the amount of heat given to the hot water can be increased by reducing the flow rate of the refrigerant with the expansion valve 14 or increasing the pressure of the refrigerant with the compressor 13.

  In the illustration of FIG. 1, the tank apparatus 2 is shown as an example of the supply destination of the hot water flowing through the hot water supply pipe h2. One end of the hot water supply pipe h2 opposite to the heating device 1 is connected to a suction port 21 provided at, for example, the upper portion of the tank device 2. The tank device 2 stores hot water supplied by the hot water supply pipe h2.

  Further, for example, one end of a hot water supply pipe h6 connected to the discharge port 22 provided in the upper part of the tank device 2 is connected. For example, a nozzle is attached to the other end of the hot water supply pipe h6, and hot water stored in the tank device 2 in a state where the nozzle is opened is discharged from the nozzle.

  In the illustration of FIG. 1, one end of a circulation pipe h <b> 3 is connected to the discharge port 23 provided in the lower part of the tank device 2. The other end of the circulation pipe h3 is connected to the first connection port of the three-way valve B1. One end of the water inlet pipe h1 opposite to the heating device 1 is connected to the second connection port of the three-way valve B1. The third connection port of the three-way valve B1 is connected to one end of the water supply pipe h4. The three-way valve B1 can selectively connect the water inlet pipe h1 to either the circulation pipe h3 or the water supply pipe h4. In a state where the incoming water pipe h1 and the circulating pipe h3 are connected, the hot water stored in the tank device 2 is supplied to the heating device 1 via the circulating pipe h3 and the incoming water pipe h1. It returns to the tank apparatus 2 after being heated. Therefore, the hot water stored in the tank device 2 can be heated without changing the amount of stored hot water. When the incoming water pipe h1 and the water supply pipe h4 are connected, hot water from the outside (in this case, water) is supplied to the heating device 1 via the water supply pipe h4 and the incoming water pipe h1, and heated by the heating device 1. After that, it is supplied to the tank device 2. Therefore, the amount of stored hot water can be increased and supplied to the tank device 2.

  The controller 4 controls the heating device 1 and the pump device 3 as described above. Here, the control unit 4 includes a microcomputer and a storage device. The microcomputer executes each processing step (in other words, a procedure) described in the program. The storage device is composed of one or more of various storage devices such as a ROM (Read Only Memory), a RAM (Random Access Memory), a rewritable nonvolatile memory (EPROM (Erasable Programmable ROM), etc.), and a hard disk device, for example. Is possible. The storage device stores various information, data, and the like, stores a program executed by the microcomputer, and provides a work area for executing the program. It can be understood that the microcomputer functions as various means corresponding to each processing step described in the program, or can realize that various functions corresponding to each processing step are realized. The controller 4 is not limited to this, and various procedures executed by the controller 4 or various means or various functions implemented may be realized by hardware.

<How to start>
In the start-up operation that is executed first in the operation of the heating system, the control unit 4 controls the expansion valve 14 and the compressor 13 based on preset initial values.

  In the start-up operation of the heating system, the pump device 3 is controlled based on a predetermined rotation speed initial value. Specifically, the rotational speed of the pump device 3 is controlled to coincide with the initial rotational speed value. As a result, hot water flows through the inlet pipe h1 and the outlet pipe h2 at a flow rate corresponding to the initial value of the rotational speed.

  However, the flow rate differs depending on the pressure loss of the water inlet pipe h1 and the hot water outlet pipe h2. As shown in FIG. 2, in order to flow the same flow rate, the larger the pressure loss of the water inlet pipe h1 and the hot water outlet pipe h2, the larger the rotational speed is required. In FIG. 2, the relationship between the rotation speed and the flow rate of hot water when the pressure loss is relatively large is shown by a solid line, and the relationship between the rotation speed and the flow rate of hot water when the pressure loss is relatively small is shown by a broken line. Has been. In FIG. 2, the relationship between the rotational speed and the flow rate of hot water is shown linearly, but in reality, a curve can be taken according to the pump performance and the like.

  Note that when the heating system is installed at a predetermined location, the initial rotational speed value is not an appropriate value according to the pressure loss. Therefore, as described below, the control unit 4 performs a process of updating the rotation speed initial value.

<How to update the initial rotation speed at startup>
The control unit 4 controls the heating device 1 and the pump device 3 so that a predetermined amount of heat is supplied to the hot and cold water, detects the rotation speed when the rotation speed of the pump device 3 is in a steady state, and the rotation speed is set in advance. When it is larger than the set reference value, the rotation speed initial value is increased and updated. Hereinafter, a specific example will be described with reference to the flowcharts of FIGS.

  The reference value is determined by executing the flowchart of FIG. First, in step S10, the control unit 4 operates the heating device 1 and the pump device 3. Specifically, for example, when the control unit 4 receives an activation command from the outside, the control unit 4 controls the heating device 1 based on a predetermined initial value and pumps based on a predetermined rotation speed initial value. The apparatus 3 is controlled.

  Next, in step S11, the control unit 4 detects the incoming temperature Tin of hot water flowing through the incoming water pipe h1 using the temperature sensor T1 provided in the incoming water pipe h1.

  Next, in step S12, the control unit 4 employs a preset hot water temperature command value Tout *. Then, the control unit 4 calculates the temperature ΔT by subtracting the incoming water temperature Tin from the tapping temperature command value Tout *. The temperature ΔT is used for the processing shown in the flowchart of FIG. The control unit 4 may add a predetermined temperature ΔT set in advance to the incoming water temperature Tin, and calculate the hot water temperature command value Tout * for the hot water outgoing temperature Tout flowing through the hot water piping h2.

  Next, at step S13, the control unit 4 detects the tapping temperature Tout by the temperature sensor T2 provided on the tapping piping h2, so that the tapping temperature Tout falls within a predetermined range centered on the tapping temperature command value Tout *. The rotational speed of the pump device 3 is controlled. Since the hot water receives the amount of heat from the heating device 1 and raises the temperature thereof by the temperature ΔT, the process in step S13 sets the rotation speed of the pump device 3 so that the control unit 4 supplies a predetermined amount of heat to the hot water. You can understand that you are controlling.

  Next, in step S14, the control unit 4 detects the rotation speed Rref when the rotation speed is in a steady state. The rotational speed Rref may be calculated from the rotational position of the electric motor included in the pump device 3 and may be calculated from the rotational position. Alternatively, the rotational speed Rref may be calculated from the value of the electric current supplied to the electric motor. The controller 4 records the rotational speed Rref on the nonvolatile recording medium that it comprises. In addition, according to the process of FIG. 3, rotation speed Rref can be grasped | ascertained as the value set based on the said predetermined calorie | heat amount supplied to hot water.

  Next, in the heating system installed in the installation environment B that is actually used, the flowchart of FIG. 4 is executed. Note that the pressure loss of the inlet pipe h1 and the outlet pipe h2 in the installation environment B is different from that in the installation environment A.

  Since the process of step S20-step S23 is the same as the process of step S10-step S13, detailed description is abbreviate | omitted. However, the heating capacity of the heat pump varies depending on the temperature of the outside air. Therefore, the heating device 1 may be controlled based on the temperature of the outside air so as to exhibit the same heating capability as the heating capability of the heating device 1 in step S10. Here, the same level of heating capacity means that the heating device 1 gives the same amount of heat to the hot water when hot water of the same flow rate is flowing through the incoming water pipe h1 and the hot water outlet pipe h2.

  According to the processing of step S20 to step S23, the temperature change of the hot water is the same temperature ΔT as in the installation environment A. Moreover, the heating device 1 exhibits the same heating ability as in the installation environment A. Therefore, the flow rate of hot water flowing through the processing of steps S10 to S13 in the installation environment A and the flow rate of hot water flowing through the processing of steps S20 to S23 in the installation environment B coincide with each other.

  Next, in step S24, the control unit 4 detects the rotational speed R when the rotational speed of the pump device 3 is in a steady state.

  Next, in step S25, the control unit 4 determines the magnitude relationship between the rotational speed R and the rotational speed Rref as a reference value. If it is determined in step S25 that the rotation speed R is greater than the rotation speed Rref, the control unit 4 increases and updates the rotation speed initial value in step S26.

  In step S25, since it is determined that the rotation speed R is higher than the rotation speed Rref, it can be inferred that the pressure loss in the installation environment B is larger than the pressure loss in the installation environment A (see also FIG. 2). Therefore, in the installation environment B, it is surmised that the flow rate at the predetermined initial value of the rotational speed does not reach the desired value, resulting in insufficient flow rate.

  According to this control method, since the rotation speed initial value is increased and updated in the process of step S26, the shortage of flow rate when the heating system is started next time can be solved.

  If it is determined in step S25 that the rotation speed R is smaller than the rotation speed Rref, the control unit 4 reduces and updates the rotation speed initial value in step S27.

  In step S25, since it is determined that the rotation speed R is smaller than the rotation speed Rref, it can be inferred that the pressure loss in the installation environment B is smaller than the pressure loss in the installation environment A. Therefore, in the installation environment B, it is presumed that the flow rate at a predetermined rotation speed initial value exceeds a desired value. If the flow rate is larger than a desired value, the period until the temperature of the hot water reaches a predetermined hot water temperature Tout becomes longer.

  According to this control method, since the rotation speed initial value is reduced and updated in the process of step S27, the period until the hot water temperature reaches the tapping temperature Tout when the heating system is started next time. Can be shortened. In other words, the rise of the temperature of the hot water can be accelerated.

  Moreover, since it is not necessary for the worker to input the pipe length, the burden on the worker is reduced and no input mistake is caused.

  In step S23, the heating device 1 is controlled so as to exhibit a heating capability comparable to the heating capability of the heating device 1 in the installation environment A, but is not necessarily limited thereto. For example, the following processing may be performed. In the installation environment A, the process of FIG. 3 is executed at a plurality of outside air temperatures to obtain a plurality of rotation speeds Rref for the plurality of outside air temperatures. In step S23, the heating apparatus 1 is controlled based on the initial value. In step S25, the outside air temperature is detected, and the magnitude relationship between the rotation speed R and the rotation speed Rref for the detected outside air temperature may be determined. .

  In step S26, the initial value of the refrigerant circulation amount may be decreased and updated together with or instead of the update of the initial value of the rotation speed, or the initial value of the compressor frequency is decreased and updated. May be. Thereby, the next problem when starting a heating system after the next time can be avoided. That is, if the flow rate does not reach the desired value, the temperature of the hot water rises more than necessary. Since the hot water in the heat exchanger 11 receives heat from the refrigerant by heat transfer, if the temperature of the hot water rises more than necessary, the hot water cannot receive heat sufficient to sufficiently reduce the refrigerant pressure. Therefore, the refrigerant pressure increases more than expected.

  According to step S26, since the refrigerant circulation amount is reduced, it is possible to avoid a situation in which the refrigerant pressure increases more than expected in the heat exchanger 11. As a result, the compressor 13 is protected.

  In step S27, the initial value of the refrigerant circulation amount may be increased and updated together with or instead of the update of the initial value of the rotational speed, or the initial value of the compressor frequency is increased and updated. Also good. Thereby, the following problem can be avoided. That is, if the flow rate exceeds the desired value, the period during which the temperature of the hot water reaches the desired value becomes longer. According to step S27, since the heating capability of the heating apparatus 1 when starting the heating system after the next time increases, the rise of the temperature of the hot water can be accelerated.

  In the example of FIG. 4, the processes of steps S26 and S27 are executed depending on whether the rotational speed R is larger or smaller than the rotational speed Rref. However, when the rotational speed R is larger than the rotational speed Rref by a predetermined value or more. Step S26 may be executed and step S27 may be executed when the rotational speed R is smaller than the rotational speed Rref by a predetermined value or more.

  Moreover, the pressure loss of the water inlet pipe h1 and the hot water outlet pipe h2 deteriorates over time due to, for example, scale adhesion. Therefore, the rotation speed Rref may be updated to the rotation speed R after execution of the processes of steps S26 and S27, and the flowchart of FIG. 4 may be executed, for example, every time the heating system is activated or every six months.

  As a result, the heating system can be started with an appropriate initial value of the rotational speed reflecting the deterioration of the pressure loss due to secular change.

DESCRIPTION OF SYMBOLS 1 Heating device 3 Pump device h1 Intake piping h2 Outlet piping T1, T2 Temperature sensor

Claims (3)

A pump device (3) for driving the hot water to flow into the inlet pipe and the outlet pipe connected thereto;
In a heating system comprising: a heating device (1) that heats the hot water flowing in through a water inlet pipe (h1) in combination with the control of the pump device, and supplies the hot water to a hot water outlet pipe (h2);
Controlling the rotational speed of the pump device so that a predetermined amount of heat is supplied to the hot water,
Detecting the rotational speed when the rotational speed of the pump device is in a steady state;
A control method in a heating system, wherein when the rotational speed is larger than a reference value set based on the predetermined value, an initial value for the rotational speed at the next operation is increased and updated. Wherein when the rotational speed at which the rotational speed is in a steady state is less than the reference value, it reduces the pre Symbol Initial value updating, the control method in a heating system according to claim 1 of the pump apparatus.   The control method in the heating system according to claim 1 or 2, wherein the control method in the heating system is repeatedly executed every predetermined period.

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