JPS6347700A - Waste-heat utilizing device for reactor coolant purifying system - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention provides a method for purifying nuclear reactor coolant that can utilize waste heat generated from equipment in the reactor coolant purification system during nuclear couplant operation. The present invention relates to a system waste heat utilization device.

(Prior Art) Generally, a nuclear couplant is provided with a reactor coolant purification system to remove fission products and corrosion products generated within the reactor during plant operation. This orientation of the purification system can reduce radiation levels generated from corrosion or fission products.

Here, a specific configuration of a conventionally used nuclear reactor coolant purification system will be explained with reference to FIG.

That is, a part of the coolant 3 taken out from the reactor pressure vessel 1 by the circulation pump 2 passes through the regenerative heat exchanger 4 and the non-regenerative heat exchanger 5, and reaches a predetermined limit temperature such as the temperature of the treated water of powdered ion exchange resin. After being further purified by a filtration and demineralization device 6, the temperature is raised by a regenerative heat exchanger 4, and then returned to the reactor pressure vessel 1 via the reactor water supply pipe 1a.

The flow rate of the coolant to be purified is normally within the range of about 1 to 2% of the reactor water supply piping, and about 4% in the case of large Q, and the flow rate is adjusted by the regulating valve 7 installed in the filtration and desalination equipment 6. be done.

The regenerative heat exchanger 4 recovers a part of the heat held by the coolant 3,
Provided to minimize thermoeconomic losses. Further, the non-regenerative heat exchanger 5 cools the cold IJ material 3 so that the temperature at which it flows into the filtration and demineralization device 6 is usually 49° C. or lower. The cooling operation is performed using cooling water supplied from the reactor auxiliary cooling system 8 via the cooling water inlet pipe 9. The flow rate of the cooling water is controlled by adjusting the opening degree of a temperature regulating valve 11 provided in the cooling water outlet pipe 10 using a temperature controller 12. The cooling water that has undergone heat exchange in the non-regenerative heat exchanger 5 and has reached a high temperature is discharged to the outside of the plant system through a cooling water outlet pipe 10.

On the other hand, a plurality of wet motor-type reactor recirculation pumps 13 are arranged in the lower part of the reactor pressure vessel 1 .
Through forced circulation, reactor output, or steam generation, is effectively controlled.

In order to prevent the electric motor from heating up during operation of the reactor recirculation pump 13, each reactor recirculation pump 13 is connected to a recirculation pump cooler 15 via a pair of cooling loop pipes 14. It is attached. The recirculation pump cooler 15 is connected to the reactor auxiliary cooling system 8, and the electric cooling water circulating through the cooling loop piping 14 and the water supplied from the reactor auxiliary cooling system 8 exchange heat. is configured to do so.

(Problems to be Solved by the Invention) However, there is a problem in that the pump capacity of the reactor recirculation pump 13 is limited by the cooling capacity of the reactor recirculation pump 13 for the electric VJ machine. That is, the temperature of the cooling water supplied from the reactor reprint cooling system 8 is relatively high at approximately 35° C., and accordingly, the temperature of the cooling water supplied from the reactor reprint cooling system 8 is relatively high, and accordingly, the cooling loop piping 14. The temperature of the cooling water flowing through the motor must also rise, which puts a limit on the cooling capacity of the motor, and the specifications of the motor have been set according to this limit. Therefore, in order to effectively perform forced circulation of the coolant, it was necessary to install a plurality of in-reactor recirculation pumps 13, which have a small calorific value.

Incidentally, in order to maintain the health of the electric motor of the reactor recirculation pump 13, it is necessary to control the temperature of the cooling water flowing into the electric tilt through the cooling loop piping 14 to about 60° C. or lower. Due to this temperature limit, high-load operation of the electric vJ was regulated. New cold n to increase cooling capacity
Providing one facility would cause equipment costs and management problems, so some kind of countermeasure was desired.

On the other hand, in the non-regenerative heat exchanger 5 of the reactor coolant purification system, the hot water that has been heated by exchanging heat with the reactor coolant 3 is discharged directly to the outside of the plant system via the cooling water outlet pipe 10. J3's retained heat a was completely discarded without any use. Therefore, in order to save the cooling water itself and to minimize the thermal economic loss of the entire plant, measures have been sought to recover and effectively utilize the aforementioned released heat as much as possible.

In view of the above points, the present invention has been developed to improve the reactor coolant purification system without impairing the functions of the thermal circulation system and cooling system of the reactor main body, and without providing a new heat source or cooling equipment. By effectively utilizing the waste heat generated in non-regenerative heat exchangers,
It is an object of the present invention to provide a waste heat utilization device for a reactor coolant purification system that can efficiently cool the electric motor of a recirculation pump in a nuclear reactor.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the waste heat utilization device for the reactor coolant purification system according to the present invention cools the reactor coolant to the reactor coolant purification system. A non-regenerative heat exchanger is provided, and the drought side, which is heated by exchanging heat with the reactor coolant in the non-regenerative heat exchanger, is connected to the regenerator of the absorption chiller, and the absorption chiller is equipped with a non-regenerative heat exchanger. The key point is that the evaporator of the refrigerator is connected to the recirculation pump cooler of the recirculation pump in the reactor.

(Function) According to the above configuration, the hot water obtained in the non-regenerative heat exchanger of the reactor coolant purification system is supplied to the regenerator of the absorption chiller as a heat source, while the cold water obtained in the evaporator of the chiller is supplied as a heat source. Since it is supplied as cooling water to the recirculation pump in the reactor, the waste heat generated in the non-regenerative heat exchanger can be effectively used, and at the same time, the regeneration efficiency in the refrigerator can be increased.

In addition, the temperature of the cold water obtained in the evaporator of the refrigerator is much lower than the water temperature of the reactor auxiliary equipment feed water that was conventionally used for cooling, so the cooling capacity of the recirculation pump cooler has been dramatically improved. do. Therefore, continuous high-load operation of the reactor recirculation pump is also possible. Furthermore, since waste heat can be effectively recovered and used, the heat balance of the entire plant is improved.

(Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a system diagram showing the configuration of a waste heat utilization device for a reactor coolant purification system according to the present invention.

A part of the coolant 3 taken out from the reactor pressure vessel 1 by the circulation pump 2 is cooled down to a predetermined temperature or lower in the regenerative heat exchanger 4 and the non-regenerative heat exchanger 5, and then transferred to the sterilization desalination device 6. After being purified there by means such as ion exchange, the temperature is raised in the regenerative heat exchanger 4, and the reactor water supply pipe 1
It is returned to the reactor pressure vessel 1 via a.

A cooling pipe 16 as a heat exchange pipe is accommodated in the non-regenerative heat exchanger 5, and one end of this cooling pipe 16 is connected to the reactor auxiliary cooling system 8 through a cooling water inlet pipe 9, and is connected to the cooling system 8 for cooling. The other end of the pipe 16 is connected to an absorption refrigerator 19 via a cooling water outlet pipe 10 and a hot water supply pipe 18 . Non-regenerative heat exchanger 5
Cooling water is supplied from the reactor auxiliary equipment cooling system 8 to the cooling pipe 16 via the cooling water inlet pipe 9, where the cooling water is heated by heat exchange and becomes hot water, which is then passed through the cooling water outlet pipe 10. guided by.

Further, the cooling water outlet pipe 10 is provided with a temperature adjustment valve 11, and the opening degree of this temperature adjustment valve 11 is controlled by a temperature control device 12 provided downstream of the non-regenerative heat exchanger 5. . By maintaining the flow rate of the cooling water appropriately, the temperature of the coolant 3 flowing into the filtration and demineralization device 6 is kept below a predetermined value.

On the other hand, an on-off valve 17 is provided downstream of the temperature adjustment valve 11, and a hot water supply pipe 18 is branched from the primary side of the on-off valve 17, and the hot water heated by the non-regenerative heat exchanger 5 is supplied to the hot water supply pipe 18. It passes through the pipe 18 and is fed to the regenerator 19a of the absorption refrigerator 19. The regenerator 19a exchanges heat with the cooling water passing through the condenser 19c, and the heat-exchanged hot water passes through the hot water return pipe 20 and returns to the secondary side of the on-off valve 17. Further, the absorber 19b and condenser 19c of the absorption refrigerator 19 are sequentially connected through a cooling water pipe 21. The cooling water guided through the cooling water pipe 21 absorbs heat at the absorption 519b and rises in temperature, and is then guided to the condenser 19c where it radiates heat.
Condensed.

Further, the absorption refrigerator 19 is provided with an evaporator 19d capable of exchanging heat with the absorber 19b.
The water passing therethrough is cooled by the absorber 19b, and the cooled cold water is supplied to the recirculation pump cooler 15 via the cold water supply pipe 22. The supplied cold water exchanges heat with the cooling water in the cooling loop piping 14 that has cooled the electric motor of the reactor recirculation pump 13, and after the temperature rises, it is transferred to the cold water return pipe 2.
3 and returns to the evaporator 19d of the absorption refrigerator 19 again.

In the above configuration, the hot water supplied to the non-regenerative heat exchanger 5 and heated by heat exchange with the coolant 3 passes through the cooling water outlet pipe 10, which is always closed.
Flows into the hot water supply pipe 18 branching from the primary side of the valve 17,
It is supplied to the regenerator 19a of the absorption refrigerator 19 as a heating source.

The hot water releases heat in the regenerator 19a to lower its temperature, then passes through the hot water return pipe 20, flows into the secondary side of the on-off valve 17, and is finally discharged outside the plant.

On the other hand, in the absorption refrigerator 19, a refrigerating action is started in the filter generator 19d by driving a refrigerant pump and an absorption liquid pump (not shown). That is, the cold water flowing through the cold water return pipe 23 is rapidly cooled when passing through the heat transfer pipe 24, and this cold water passes through the cold water supply pipe 22 again and is cooled by the recirculation pump! A
is supplied to the container 15. In the recirculation pump cooler 15, heat is exchanged with the cooling water in the cooling loop piping 14 that has cooled the electric motor of the in-reactor recirculation pump 13, and the electric motor is maintained at a predetermined temperature or lower. Further, the cold water heated by the recirculation pump cooler 15 passes through the cold water return pipe 23 and returns to the evaporator 19d of the absorption refrigerator n19 again.

In this way, the waste heat in the non-regenerative heat exchanger of the reactor coolant purification system, which was conventionally wastefully discharged outside the plant during plant operation, can be effectively utilized and transferred to the atomic energy via the absorption chiller. The electric motor of the furnace recirculation pump can be cooled efficiently.

In the above embodiment, the temperature of the hot water at the outlet of the non-regenerative heat exchanger 5 was set to approximately 90°C, and the maximum flow rate was set to approximately 90°C. If it is set that the water is supplied to the regenerator 19a of one absorption chiller at a rate of 240 m3/H and the water is changed to a dry state of approximately 82°C, then the absorption chiller 1
The heat removal performance of No. 9 is approximately 500 refrigeration tons (USRT).

On the other hand, the cooling load of the recirculation pump cooler that cools the 'FX ljJ machine of the reactor recirculation pump 13 is up to 400.
Since it is approximately 1000 ton (USRT) of refrigeration, an absorption chiller with the above specifications can be used satisfactorily.

In the embodiment shown in Fig. 1, the cold water piping connecting the absorption chiller and the recirculation pump cooler is formed in a closed loop so that the cold water circulates between them. Volume is saved.

On the other hand, if cold water is supplied from outside sequentially and the water temperature is relatively low, which is advantageous for the heat balance in cooling operations, the cooling piping is formed as a temporary water flow system rather than a circulating closed loop piping. You can also do that. In this case, the heat transfer gradient in the recirculation pump cooler increases, thereby improving the cooling capacity.

In addition, the recirculation pump cooler operates continuously during reactor operation, and the reactor coolant purification system is also operated at the same time. Since the 1 fl cooling capacity of the motor of the circulation pump also increases or decreases in proportion, it has the advantage of being able to easily respond to changes in output.

Furthermore, in this embodiment, cold water generated by absorption refrigeration is used as the cooling water for the recirculation pump cooler, and this cold water has a temperature sufficiently lower than that of conventional reactor auxiliary equipment feed water. This improves the cooling capacity in the recirculation pump cooler. Therefore, the integrity of the reactor recirculation pump can be maintained, and the motor capacity of the recirculation pump can be increased to the upper limit of the refrigerating capacity of the absorption chiller. Since the circulation pump can be operated under high load and the coolant circulation rAm in the reactor core can be increased, the operating performance of the nuclear reactor can be improved.

In addition, since the circulation capacity per 11 electric reactor recirculation pumps can be increased, the number of reactor recirculation pumps that were conventionally installed in multiple units in the reactor pressure vessel can be reduced. Can be done. Further, if the electric motor capacity 61 is changed from the same, the recirculation pump cooler can be downsized, which is extremely advantageous in designing the equipment arrangement inside the reactor containment vessel, which is a narrow space.

According to this embodiment, the reactor coolant purification system does not affect the original functions of the reactor, such as the high-temperature thermal circulation system that drives the turbines, etc., and does not require a new cold source. Since the waste heat of the non-regenerative heat exchanger can be effectively used for cooling the electric motor of the reactor recirculation pump via the refrigerator, the thermal economic loss of the entire nuclear couplant can be reduced.

〔Effect of the invention〕

As explained above, according to the present invention, waste heat obtained from non-regenerative heat exchange products is converted into cold water by an absorption chiller, and the cold water is supplied as cooling water for the recirculation pump in the reactor. Waste heat is effectively recovered and used, improving the heat balance of the entire plant.

In addition, the temperature of the cold water obtained in the refrigerator evaporator is much lower than that of conventional reactor auxiliary equipment water supply, so the recirculation pump cooling 1
The cooling capacity in one device can be significantly improved. Therefore, it is possible to operate the in-reactor recirculation pump continuously under high load, downsize the pump body, and reduce the number of units installed.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing the configuration of one practical example of the present invention, and FIG.
The figure is a system diagram showing the configuration of a conventional reactor coolant purification system. 1... Reactor pressure vessel, 1a... Reactor water supply piping,
2... Circulation pump, 3... Coolant, 4... Regenerative heat exchanger, 5... Non-regenerative heat exchanger, 6... Filtration desalination device, 7... Regulating valve, 8 ...Reactor auxiliary cooling system, 9.
...Cooling water inlet piping, 10...Cooling water outlet piping, 11
...Temperature adjustment valve, 12...Temperature controller, 13...
In-reactor recirculation pump, 14...Cooling loop piping, 1
5... Recirculation pump cooler, 16... Cooling pipe, 17
... Opening/closing valve, 18... Hot water supply pipe, 19... Absorption refrigerator, 19a... Regenerator, 19b... Absorber,
19c... Condenser, 19d... Evaporator, 20...
Hot water return pipe, 21... Cooling water pipe, 22... Cold water supply pipe, 23... Cold water return pipe, 24... Heat transfer tube. Representative Patent Attorney Noriyuki Chika Yudo Hirofumi Mimata Figure 1

Claims (1)

[Scope of Claims] 1. In a waste heat utilization apparatus for a reactor coolant purification system, the reactor coolant purification system is equipped with a non-regenerative heat exchanger for cooling the reactor coolant, wherein the non-regenerative heat exchanger The hot water side, which is heated by exchanging heat with the reactor coolant, is connected to the regenerator of the absorption chiller, and the evaporator of the absorption chiller is connected to the recirculation pump cooling of the recirculation pump in the reactor. A waste heat utilization device for a nuclear reactor coolant purification system characterized by being connected to a reactor coolant purification system. 2. In the reactor coolant purification system according to claim 1, the absorption chiller and the recirculation pump cooler are connected by a cold water pipe formed in a closed loop so that the cold water mutually circulates. Waste heat utilization equipment.