JP2019120444A - Cooling device - Google Patents

Abstract

To suppress a drainage volume by eliminating the need of in-house water to be consumed for cooling hot-water drain that is generated when steam is separated from high temperature drain, and to miniaturize a device.SOLUTION: A cooling device includes: a steam drum; and a chiller provided integrally with the steam drum inside the steam drum to cool hot-water drain that is generated when steam is separated from high temperature drain flowing into the steam drum.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cooling device.

  In a nuclear power plant etc., in order to drain the high temperature drain generated at the time of startup, a blow-down tank incorporating a cyclone separator etc. is installed. Usually, in the blow-down tank, in order to drain the high temperature drain, the high temperature drain introduced inside is separated into steam and a hot water drain. The blowdown tank releases steam from the exhaust pipe to the atmosphere and discharges the hot water drain to the drainage tank while cooling it, but the hot water drain is cooled to a temperature that can be further received by the drainage tank. Cooling water is injected into the drainage pipe for draining the drain and mixed.

  Patent Document 1 discloses a blow-down tank which is disposed downstream of a boiler or a turbine and includes means for preventing high temperature steam from flowing into the flow path of the drainage pipe.

JP, 2014-238239, A

  In the background art, since the temperature difference between the hot water drain and the cooling water is small, it is necessary to mix a large amount of water with the hot water drain to cool the hot water drain, and the amount of drainage discharged to the drainage tank increases significantly. In addition, there may be a shortage of local water consumed to cool the hot water drain.

  In the blow-down tank described in Patent Document 1, a drainage cooler is disposed between a drainage pipe for draining the hot water drain and a drainage tank from which the hot water drain is drained, and cold water is allowed to flow through the drainage cooler. The temperature of the hot water drain flowing in the drainage pipe is cooled. In this case, since the blow-down tank and the drainage cooler are separately provided, there is a possibility that the facility for cooling the hot water drain may become large. Moreover, in such a facility, since the drainage cooler is installed downstream of the blow-down tank, the place for installing the blow-down tank is limited.

  The present invention solves the above-mentioned problems, and an object of the present invention is to reduce the amount of in-house water consumed as cooling water to suppress the amount of drainage discharged to the drainage tank, and to provide a compact cooling device.

  In order to solve the problems described above, the cooling device according to the present invention is provided integrally with the steam drum and the steam drum inside the steam drum, and the high temperature drain flowing into the steam drum is separated by brackish water and generated. And a cooler for cooling the hot water drain.

  With this structure, since the cooler is provided inside the steam drum, the cooling structure of the hot water drain can be miniaturized.

  Preferably, the steam drum further comprises a steam separator for the high temperature drain to the flash steam and the hot water drain.

  With this structure, the hot water drain can be stored inside the steam drum. Therefore, the hot water drain can be cooled by the cooler provided inside the steam drum.

  Preferably, the steam separator is a cyclone separator in which the high temperature drain swirls along the inner wall of the steam drum.

  With this structure, existing equipment can be used for the steam drum. Therefore, since it is not necessary to prepare a new steam drum, it is versatile and advantageous from the viewpoint of cost.

  Preferably, the steam separator further comprises an inner cylinder provided inside the steam drum.

  This structure facilitates discharging the flashed vapor out of the steam drum. Therefore, the pressure inside the steam drum can be easily maintained at atmospheric pressure.

  Moreover, it is preferable to cool the said cooler in contact with the warm water drain stored in the lower part of the said steam drum.

  This structure allows the cooler to indirectly exchange heat with the hot water drain. Therefore, the hot water drain can be cooled efficiently.

  Preferably, the cooler has a height equal to or less than the depth of the hot water drain stored in the lower portion of the steam drum.

  This construction allows for the use of appropriately sized coolers. Therefore, it is advantageous from the viewpoint of cost.

  Moreover, it is preferable that the said cooler is a vertical heat exchanger.

  This construction allows the cooler to use existing equipment. Therefore, it can be applied to existing nuclear power plants.

  Moreover, it is preferable to further provide a supply pipe for supplying a medium for cooling the hot water drain to the cooler, and a discharge pipe for discharging the medium heated by the hot water drain from the cooler.

  With this structure, the liquid for cooling the hot water drain can be recovered without being mixed with the hot water drain. Therefore, it is possible to dispense with the in-house water consumed to cool the hot water drain.

  Moreover, it is preferable that the said supply piping is connected with a condenser, and the said medium is the condensate supplied from the said condenser.

  By this structure, the condensate of the condensate system in a nuclear power plant etc. can be used as a cooling medium of a warm water drain. Therefore, it is possible to dispense with the in-house water consumed to cool the hot water drain.

  Moreover, it is preferable that the said discharge piping is connected with the said condenser, and the said condensed water which flowed out out of the said discharge piping is discharged | emitted by the said condenser.

  With this structure, it is possible to reuse the condensed water after cooling the hot water drain. Therefore, the amount of makeup water supplied to the condenser can be reduced to compensate for the shortage of the condensate.

  Moreover, it is preferable to have a vapor | steam collection | recovery pipe | tube for collect | recovering the vapor | steam discharged | emitted from the said steam drum in air | atmosphere, It is preferable that the said steam collection | recovery pipe | tube is connected to the said condenser.

  With this structure, steam released to the atmosphere can be recovered as condensate used to cool the hot water drain. Therefore, it is possible to further reduce the amount of makeup water supplied to the condenser to compensate for the shortage of the condensate.

  Moreover, it is preferable that the said medium is seawater.

With this structure, seawater can be used as a high temperature drain liquid refrigerant. Therefore, it is possible to dispense with the in-house water consumed to cool the hot water drain.

  According to the cooling device of the present invention, since the cooler for cooling the hot water drain generated by separating the high temperature drain by brackish water is provided inside the steam drum, the cooling facility of the hot water drain in a nuclear power plant etc. is miniaturized. be able to. Further, according to the cooling device of the present invention, since the condensed water is used as a cooling medium for cooling the hot water drain, the amount of water necessary for cooling the hot water drain can be reduced.

FIG. 1 is a schematic view showing the configuration of a cooling device according to an embodiment of the present invention. FIG. 2 is a top cross-sectional view of a steam drum provided in a cooling device according to an embodiment of the present invention. FIG. 3 is a schematic view showing an outline of a nuclear power plant in which the cooling device of the present embodiment is used. FIG. 4 is a schematic view showing an outline of a nuclear power plant in which a cooling device according to a modification of the present embodiment is used.

  Hereinafter, preferred embodiments of a cooling device according to the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited by the embodiments, and in the case where there are a plurality of embodiments, the present invention also includes those configured by combining the respective embodiments.

  FIG. 1 is a schematic view showing the configuration of a cooling device according to an embodiment of the present invention. As shown in FIG. 1, the cooling device includes a steam drum 110, a cooler 120, a supply pipe 130, a discharge pipe 140, a pipe plate 150, an inner cylinder 160, and a drain discharge pipe 170.

  The steam drum 110 has a drain introduction pipe 111, a steam discharge pipe 112, a first water chamber 113, and a second water chamber 114.

  The drain introduction pipe 111 is provided to introduce a high temperature drain from the circumferential direction of the steam drum 110. For example, in a nuclear power plant, a two-phase flow of saturated steam generated at the start of the plant and saturated water. It is a pipe for introducing the high temperature drain into the steam drum 110.

  The steam discharge pipe 112 is provided at the top of the steam drum 110, and is a pipe that generates steam inside the steam drum 110 and passes the inner cylinder 160 into the atmosphere.

  Referring to FIG. 2, the flow until the flash steam generated inside the steam drum is discharged will be described. FIG. 2 is a schematic view showing the internal structure of the steam drum 110. As shown in FIG. In addition, in FIG. 2, although high temperature drain is demonstrated as what is introduce | transduced into the inside of the steam drum 110 from two places, this invention is not limited.

  As shown in FIG. 2, the drain introducing pipe 111 introduces a high temperature drain into the inside of the steam drum 110 from the circumferential direction of the steam drum 110. The high temperature drain that has flowed into the steam drum 110 is brackish water separated into flush steam and hot water drain. The flush steam swirls along the outer periphery of the inner cylinder 160 because the drain introduction pipe 111 is provided along the circumferential direction of the steam drum 110. Then, the flash steam is introduced into the inner cylinder 160 and discharged from the steam discharge pipe 112 provided at the top of the steam drum 110. Thereby, the inside of the steam drum 110 is maintained at atmospheric pressure. The hot water drain is stored on the steam drum 110.

  The first water chamber 113 and the second water chamber 114 are provided in the lower part of the steam drum 110 separated by the tube sheet 150. In the first water chamber 113, a liquid for cooling the hot water drain is supplied and temporarily stored. In the second water chamber 114, a heated liquid after heat exchange with the hot water drain is introduced and temporarily stored. A partition plate 115 is provided between the first water chamber 113 and the second water chamber 114 so as not to mix the liquid stored in each other. In the upper space divided by the tube sheet 150, a warm water drain of depth D is stored.

  The cooler 120 is a cooler that can cool the temperature of the hot water drain by indirectly exchanging heat with the hot water drain. The cooler 120 is, for example, a multi-tube vertical heat exchanger, and is integrally provided with the steam drum 110 via the tube sheet 150 inside the steam drum 110. Specifically, the cooler 120 is provided on the tube sheet 150 so as to connect the first water chamber 113 and the second water chamber 114. That is, the cooler 120 has a structure in which the liquid stored in the first water chamber 113 flows into the inside of the cooler 120 and the liquid that has passed through the inside of the cooler 120 flows out into the second water chamber 114. It has become. Thus, the cooler 120 can cool the hot water drain indirectly by heat exchange with the hot water drain stored in the steam drum 110. Specifically, liquid for cooling the warm water drain (for example, 100 to 120 ° C.) to a predetermined allowable temperature (for example, around 60 ° C.) can be allowed to flow through the cooler 120. Although there is no restriction | limiting in particular in the liquid sent through the cooler 120, For example, the condensate and seawater which are supplied from the condensate system used for the nuclear power plant can be raised. The temperature of the liquid flowing through the cooler 120 to cool the hot water drain is not particularly limited as long as the temperature is lower than that of the hot water drain, and is, for example, cold water of about 30 ° C. In addition, when using seawater, it is preferable to take the corrosion countermeasure for preventing corrosion, such as rust. Further, the height T of the cooler 120 is preferably equal to or less than the depth D of the hot water drain. This is because the cooler 120 is provided to cool the hot water drain stored in the steam drum 110, and therefore, it is not necessary to raise the temperature to a position where the hot water drain does not reach. Making the cooler 120 smaller is also advantageous from the viewpoint of cost.

  The supply pipe 130 supplies a liquid for cooling the hot water drain to the cooler 120. Specifically, the supply pipe 130 is connected to the first water chamber 113, and supplies the first water chamber 113 with a liquid for cooling the hot water drain. Then, the liquid supplied to the first water chamber 113 is supplied to the cooler 120 from the first water chamber 113. The liquid supplied to the cooler 120 by the supply piping 130 is, for example, condensed water or seawater.

  The discharge pipe 140 passes the cooler 120 and discharges the liquid after cooling the hot water drain. Specifically, the discharge pipe 140 is connected to the second water chamber 114, and discharges the liquid stored in the second water chamber 114 provided inside the steam drum 110. The discharge pipe 140 is provided with a discharge regulator 141. By providing the discharge amount adjuster 141, the amount of liquid to be discharged from the steam drum 110 can be adjusted. The emission regulator 141 is, for example, opened at the start of the nuclear power plant, but is not limited thereto. The emission regulator 141 may, for example, be open during normal operation of the nuclear plant. This is because a high temperature drain is generated in a small amount even during normal operation of the nuclear power plant, and the high temperature drain flows into the steam drum 110. Although there is no particular limitation on such a discharge regulator 141, for example, an orifice, a ball valve (manual valve), and a control valve can be mentioned. The discharge pipe 140 is connected to, for example, a condenser in a condensate system of a nuclear power plant. In this case, the discharge pipe 140 discharges the liquid heated by the hot water drain discharged from the cooler 120 to the condenser.

  The drain discharge pipe 170 discharges the cooled hot water drain. Specifically, the drain discharge pipe 170 is provided on the steam drum 110, drains the hot water drain cooled by the cooler 120, and supplies it to the drain tank 180. A drain water amount adjuster 171 is provided in the drain discharge pipe 170. By providing the drain water amount adjuster 171, the amount of hot water drain stored in the steam drum 110 can be adjusted. Although there is no restriction | limiting in particular in such a drain water volume regulator 171, For example, a control valve can be raised.

  The drainage tank 180 temporarily stores the drain discharged from the steam drum 110. A drainage pipe 190 is provided in the drainage tank 180. The drainage pipe 190 sucks up the drain stored in the drainage tank 180 by the pump 191 and drains it to a drainage processing facility or the like.

  FIG. 3 is a schematic view showing an outline of a nuclear power plant 1 in which the cooling device of the present embodiment is used.

  The nuclear power plant 1 includes a cooling device 100, a condenser 10, a steam generator 20, a supply amount regulator 21, a low pressure feed water heater 22, a deaerator 23, a feed water pump 24, and high pressure feed water heating. And a moisture separation heater 26, a high pressure turbine 31, a low pressure turbine 32, and a condensate pump 41. First, the flow of generating electric power in the nuclear power plant 1 will be described with reference to FIG.

  The heated primary coolant (water, liquid) is supplied to the steam generator 20 by a coolant pump, for example, from a Pressurized Water Reactor (PWR). Then, the steam generator 20 evaporates the secondary coolant by heat-exchanging the high temperature primary coolant with the secondary coolant, and supplies the evaporated secondary coolant (steam) toward the high pressure turbine 31. Do.

  The high pressure turbine 31 is rotated by the steam supplied from the steam generator 20, and discharges the used steam toward the moisture separation heater 26.

  The moisture separation heater 26 removes moisture from the steam received from the high pressure turbine 31, heats it, and discharges it toward the low pressure turbine 32.

  The low pressure turbine 32 is rotated by the steam supplied from the moisture separation heater 26 and discharges the used steam to the condenser 10.

  As described above, in the nuclear power plant 1, power generated by the steam generated by the steam generator 20 is generated by rotating the generator (not shown) by the rotation of the high pressure turbine 31 and the low pressure turbine 32.

  Next, in the nuclear power plant 1, a flow until condensed water is generated and supplied to the steam generator 20 will be described.

  The condenser 10 condenses the steam discharged from the low pressure turbine 32 by a cooling line (not shown) provided therein, and generates condensed water. Condensed water is supplied from the condenser 10 toward the low pressure feed water heater 22.

  The low pressure feed water heater 22 heats the condensed water received from the condenser 10 in a low pressure state. The low pressure feed water heater 22 supplies the heated condensate to the deaerator 23. Further, on the inflow side of the condensed water of the low-pressure feedwater heater 22, a supply amount adjuster 21 is provided. The amount of condensed water supplied to the low pressure feed water heater 22 can be adjusted by the supply amount adjuster 21.

  The deaerator 23 heats and degasses the condensed water received from the low pressure feed water heater 22. The deaerator 23 supplies the high pressure feed water heater 25 with the deaerated condensed water.

  The high pressure feed water heater 25 heats the condensed water degassed by the deaerator 23 in a high pressure state. The high pressure feed water heater 25 supplies the heated condensate to the pressurized water reactor. Further, a water supply pump 24 is provided between the deaerator 23 and the high pressure water supply heater 25. The feed water pump 24 supplies condensed water from the deaerator 23 toward the high pressure feed water heater 25.

  As described above, in the nuclear power plant 1, the condensate generated by the condenser 10 passes through the low-pressure feedwater heater 22, the deaerator 23, the feedwater pump 24, and the high-pressure feedwater heater 25. , Reach the steam generator 20.

  In the present embodiment, the hot water drain in the steam drum 110 is cooled using the condensate generated in the condenser 10, and the condensate used for cooling is discharged to the condenser 10. In the following, a flow of discharging condensed water from the steam drum 110 and using the discharged condensed water to cool the warm water drum inside the steam drum 110 will be described.

  As shown in FIG. 3, one end of the discharge pipe 140 is connected to the second water chamber 114, and the other end is connected to the condenser 10. Therefore, the condensed water stored in the second water chamber 114 is discharged to the condenser 10. The condensed water discharged to the condenser 10 is cooled by the cooling line of the condenser 10. In addition, the discharge pipe 140 is provided with a discharge amount adjuster 141. The amount of condensed water discharged from the second water chamber 114 can be adjusted by the discharge amount adjuster 141.

  One end of the supply pipe 130 is connected to the first water chamber 113, and the other end is connected between the pipe connecting the condenser 10 and the supply amount adjuster 21. Therefore, in the present embodiment, the condensate discharged from the second water chamber 114 and cooled by the condenser 10 can be supplied to the first water chamber 113 again. Specifically, a condensate pump 41 is provided between the supply pipe 130 and the condenser 10, and the condensate pump 41 supplies condensate from the condenser 10 toward the supply pipe 130. Do. Thereby, the condensed water passes through the supply pipe 130 and is supplied to the first water chamber 113.

  As described above, in the present embodiment, a cooler for cooling the hot water drain generated by the high temperature drain being separated by the brackish water is provided inside the steam drum 110. Thereby, this embodiment can make equipment for cooling a warm water drain smaller in a nuclear power plant etc. more.

  Further, in the present embodiment, condensed water is used as a liquid for cooling the hot water drain generated by the high temperature drain being separated by brackish water. Thus, the present embodiment can eliminate the need for in-house water consumed for cooling the hot water drain in a nuclear power plant or the like.

  Further, in the present embodiment, a vertical heat exchanger is used as the cooler 120. As a result, even when the present embodiment is applied to an existing nuclear power plant or the like, it can be applied without the occurrence of a large-scale construction, which is advantageous also from the viewpoint of cost.

  FIG. 4 is a schematic view showing an outline of a nuclear power plant 1A in which the cooling device of the present embodiment is used.

  In the present embodiment, the flash steam generated in the steam drum 110 is released to the atmosphere by the steam discharge pipe 112. In the modification of the present embodiment shown in FIG. 4, a steam recovery pipe 116 for recovering flash steam is provided at the top of the steam drum 110.

  The steam recovery pipe 116 recovers the flash steam generated inside the steam drum 110. The steam recovery pipe 116 supplies the recovered flash steam to the condenser 10. In addition, it is preferable that the steam recovery pipe 116 be provided with a pressure controller 117 that adjusts the pressure inside the steam drum 110. The pressure controller 117 can control the pressure inside the steam drum 110 at a constant level.

  The condenser 10 generates condensed water from the flashed steam recovered by the steam recovery pipe 116 by a cooling line provided therein.

  As described above, in the modification of this embodiment, the flash steam generated inside the steam drum 110 can also be used as the condensate. Thereby, in the nuclear power plant etc., the modification of this embodiment can reduce the amount of replenishment water replenished to the condenser 10 in order to compensate for the deficiency of condensate.

1, 1 A Nuclear Power Plant 10 Condenser 20 Steam Generator 21 Supply Regulator 22 Low Pressure Feed Heater 23 Deaerator 24 Feed Pump 25 High Pressure Feed Heater 26 Moisture Separation Heater 31 High Pressure Turbine 32 Low Pressure Turbine 41 Condensed Water Pump 100 Cooling device 110 Steam drum 111 Drain introduction piping 112 Steam discharge piping 113 First water chamber 114 Second water chamber 115 Partition plate 116 Steam recovery piping 117 Pressure controller 120 Cooler 130 Supply piping 140 Discharge piping 141 Discharge Regulator 150 Tube plate 160 Inner cylinder 170 Drain discharge piping 171 Drain water volume regulator 180 Drain tank 190 Drain piping

Claims (12)

With a steam drum,
A cooler which is integrally provided with the steam drum inside the steam drum and cools a hot water drain generated by the high temperature drain flowing into the steam drum being separated by brackish water;
Equipped with a cooling device.   The cooling device according to claim 1, wherein the steam drum further comprises a steam separator separating the high temperature drain into flush steam and hot water drain.   The cooling device according to claim 2, wherein the steam separator is a cyclone separator in which the high temperature drain swirls along an inner wall of the steam drum.   The cooling device according to claim 2, wherein the steam separator further includes an inner cylinder provided inside the steam drum.   The cooling device according to any one of claims 1 to 4, wherein the cooler cools in contact with a hot water drain stored in a lower portion of the steam drum.   The cooling device according to claim 5, wherein the cooler has a height equal to or less than a depth of a hot water drain stored in a lower portion of the steam drum.   The cooling device according to any one of claims 1 to 6, wherein the cooler is a vertical heat exchanger. Supply piping for supplying a medium for cooling the hot water drain to the cooler;
The cooling device according to any one of claims 1 to 7, further comprising: a discharge pipe for discharging the medium heated by the hot water drain from the cooler. The supply piping is connected to a condenser,
The cooling device according to claim 8, wherein the medium is condensed water supplied from the condenser. The discharge pipe is connected to the condenser,
The cooling device according to claim 9, wherein the condensed water which has flowed out from the discharge pipe is discharged to the condenser. A steam recovery pipe for discharging the steam released from the steam drum to the atmosphere;
The cooling device according to claim 9, wherein the steam recovery pipe is connected to the condenser.   The cooling device according to claim 8, wherein the medium is seawater.

Images