CN116959758A - Low-power circulating operation system of high-temperature gas cooled reactor - Google Patents

Abstract

The application provides a low-power circulating operation system of a high-temperature gas cooled reactor, which comprises a steam generator, a main steam main pipe, a first branch pipe, a first bypass valve, a condenser, a second branch pipe, a discharge valve, a third branch pipe, a pressure-reducing and temperature-reducing assembly and an auxiliary steam header; the steam generator is connected with the main steam main pipe; one end of the first branch pipe is connected with the main steam main pipe and forms a first connecting point, and the other end of the first branch pipe is connected with the condenser; the first bypass valve is arranged on the first branch pipe; one end of the second branch pipe is connected with the main steam main pipe and forms a second connection point, and the discharge valve is arranged on the second branch pipe; one end of the third branch pipe is connected with the second branch pipe and forms a third connection point, the other end of the third branch pipe is connected with the auxiliary steam header, and the pressure-reducing and temperature-reducing assembly is arranged on the third branch pipe. The application has the technical effects of reasonable design and greatly improves the running stability, safety and reliability of the reactor.

Description

Low-power circulating operation system of high-temperature gas cooled reactor

Technical Field

The application belongs to the technical field of high-temperature gas cooled reactors, and particularly relates to a low-power circulating operation system of a high-temperature gas cooled reactor.

Background

The high-temperature gas cooled reactor is designed into a modular steam supply system, comprises two or more nuclear steam supply systems, and enters a steam turbine to apply work after converging main steam main pipes or is discharged to a condenser through a first bypass valve of the steam turbine. Therefore, the operation of the high-temperature gas cooled reactor is extremely dependent on the normal operation of the first bypass valve and the condenser, and when the first bypass valve or the condenser fails to work, the reactor is shut down. For example, a certain thermopile plant has had a two start-stop operating event during the commissioning period. Firstly, in the overhaul process of the shutdown condensate pump, air is introduced into a cavity of the operation condensate pump due to the fact that an isolation boundary is not tight, cavitation of the operation condensate pump is caused, output is reduced, pressure and flow of the temperature-reduced water are reduced, a first bypass valve of the steam turbine is closed due to the fact that the temperature of a pipeline behind the valve reaches a protection value, then the reactor is not cooled, and the cold helium temperature rises to trigger shutdown; and the other is that the circulating water pump B is stopped due to the fact that the temperature winding wiring looseness indication increases, and the standby pump is not started due to defects, so that a condenser cold source is lost, the condenser is not available, and shutdown is forced to be carried out. Because the high temperature reactor needs continuous refueling to maintain the reactor core in a good working state, if the reactor is shut down, fuel circulation cannot be performed, and after the reactor is shut down, the reactor is started for a long period, so that the efficiency and the economy of the power plant are seriously affected.

Therefore, there is a need to design a low-power circulating operation system of a high-temperature gas cooled reactor, which can controllably discharge steam generated by the reactor under the working conditions of unavailable first bypass valve or condenser of the steam turbine or lost circulating water, so that enough time is available for reducing the power of the reactor to a lower level and recovering the cold source, and after the two-loop cold source is recovered, the system is circulated to maintain the circulating refueling under the stable operation state of the two-phase flow at the outlet of the steam generator.

Disclosure of Invention

The application aims at solving at least one of the technical problems existing in the prior art and provides a novel technical scheme of a low-power circulating operation system of a high-temperature gas cooled reactor.

According to one aspect of the present application, there is provided a low power cycle operation system of a high temperature gas cooled reactor, comprising:

the device comprises a steam generator, a main steam main pipe, a first branch pipe, a first bypass valve and a condenser, wherein the steam generator is connected with the main steam main pipe; one end of the first branch pipe is connected with the main steam main pipe and forms a first connecting point, and the other end of the first branch pipe is connected with the condenser; the first bypass valve is arranged on the first branch pipe;

the second branch pipe is connected with the main steam main pipe at one end and forms a second connection point, the second connection point is positioned at one side of the first connection point, which is close to the steam generator, and the discharge valve is arranged on the second branch pipe;

the system comprises a third branch pipe, a pressure-reducing and temperature-reducing assembly and an auxiliary steam header, wherein one end of the third branch pipe is connected with the second branch pipe to form a third connecting point, the third connecting point is positioned between the second connecting point and the discharge valve, the other end of the third branch pipe is connected with the auxiliary steam header, and the pressure-reducing and temperature-reducing assembly is arranged on the third branch pipe;

when the condenser is not available, closing the first bypass valve and opening the discharge valve, and discharging steam in the main steam main pipe through the second branch pipe; when the decompression and temperature reduction assembly is opened, part of steam is discharged to the auxiliary steam header through the third branch pipe after decompression and temperature reduction so as to heat water in the deaerator.

Optionally, the low-power circulating operation system of the high-temperature gas cooled reactor further comprises a first isolation valve, a second isolation valve and a third isolation valve;

the first isolation valve and the second isolation valve are both arranged on the second branch pipe, the first isolation valve is positioned between the discharge valve and the second connection point, and the second isolation valve is positioned on one side of the discharge valve away from the second connection point;

the third isolation valve is arranged on the third branch pipe, and the third isolation valve is positioned between the third connection point and the pressure-reducing and temperature-reducing component.

Optionally, the low-power circulating operation system of the high-temperature gas cooled reactor further comprises a desalting water tank, a deaerator, a first condensate water supplementing pump, a second condensate water supplementing pump, a recycling pipe, a first water supplementing valve and a second water supplementing valve; the desalination water tank is connected with the deaerator, a first condensate water supplementing pump and a second condensate water supplementing pump are arranged on a connecting pipeline between the desalination water tank and the deaerator, the first condensate water supplementing pump and the second condensate water supplementing pump are connected in parallel and form a fourth connecting point and a fifth connecting point, the fourth connecting point is connected with the desalination water tank, and the fifth connecting point is connected with the deaerator; the fifth connecting point is connected with the demineralized water tank through the recycling pipe, and the recycling pipe provides minimum flow protection for the first condensate water supplementing pump and the second condensate water supplementing pump;

the first water supplementing valve is arranged on a connecting pipeline between the fifth connecting point and the deaerator, and is used for supplementing condensation water to the deaerator;

the fifth connecting point is connected with the pressure-reducing and temperature-reducing assembly, the second water supplementing valve is arranged on the connecting pipeline of the fifth connecting point and the pressure-reducing and temperature-reducing assembly, and the pressure-reducing and temperature-reducing water is supplemented into the pressure-reducing and temperature-reducing assembly through the second water supplementing valve.

Optionally, the low-power circulation operation system of the high-temperature gas cooled reactor further comprises an inlet valve, an outlet valve, a second bypass valve, a fifth branch pipe, a sixth branch pipe, a steam-water separator, a first drain valve, a second drain valve and a drain cooler;

one end of the fifth branch pipe is connected with the main steam main pipe to form a sixth connection point, the other end of the fifth branch pipe is connected with the steam-water separator, and the inlet regulating valve is arranged on the fifth branch pipe; one end of the sixth branch pipe is connected with the steam-water separator, the other end of the sixth branch pipe is connected with the main steam main pipe to form a seventh connection point, and the second bypass valve is arranged on a connection pipeline between the sixth connection point and the seventh connection point; the sixth connecting point, the seventh connecting point, the second connecting point and the first connecting point are sequentially arranged on the main steam main pipe along the direction away from the steam generator; a first drain valve is arranged between the steam-water separator and the condenser;

the outlet medium of the steam generator can enter the steam-water separator through the fifth branch pipe to be subjected to steam-water separation, steam enters the main steam main pipe through the outlet valve, and water enters the condenser through the first drain valve; the outlet medium of the steam generator can be output by the main steam main pipe through the second bypass valve;

the steam-water separator is connected with the drain cooler, the second drain valve is arranged between the steam-water separator and the drain cooler, and the steam-water separator can drain water to the drain cooler through the second drain valve.

Optionally, the low-power circulation operation system of the high-temperature gas cooled reactor further comprises a circulation cooling assembly and a water supplementing loop, wherein the circulation cooling assembly is connected with the drain cooler and used for cooling drain water in the drain cooler;

the water supplementing loop is connected with the circulating cooling assembly and used for supplementing water into the circulating cooling assembly.

Optionally, the circulating cooling assembly comprises a cooling water tower, a circulating water pump, a water supply isolation valve and a return water isolation valve;

a circulating water pump and a water supply isolation valve are arranged on the water supply pipelines of the cooling water tower and the drain cooler, and the water supply isolation valve is positioned on one side of the circulating water pump, which is close to the drain cooler;

and the return water isolation valve is arranged on the return water pipelines of the cooling water tower and the drain cooler.

Optionally, the low-power circulation operation system of the high-temperature gas cooled reactor further comprises a drain tank, wherein the drain tank is connected with the drain cooler and is used for collecting drain cooled by the drain cooler.

Optionally, the high-temperature gas cooled reactor low-power circulating operation system further comprises a drainage pump and a drainage valve;

the drainage box is connected with the deaerator, the drainage pump and the drainage valve are arranged on the connecting pipeline of the drainage box and the deaerator, and the drainage valve is positioned on one side of the drainage valve close to the deaerator.

Optionally, the low-power circulating operation system of the high-temperature gas cooled reactor further comprises a water drain valve and a liquid level transmitter;

the drain valve and the liquid level transmitter are respectively connected with the drain tank, and drain water in the drain tank can be discharged through the drain valve;

the liquid level transmitter is used for controlling the liquid level in the hydrophobic tank to be a preset value through a water drain valve.

Optionally, the low-power circulation operation system of the high-temperature gas cooled reactor further comprises a pressure sensor, wherein the pressure sensor is arranged in the main steam main pipe, and the pressure sensor is positioned between the seventh connection point and the second connection point.

The application has the technical effects that:

in the embodiment of the application, when the condenser is not available, the first bypass valve is closed and the discharge valve is opened, steam in the main steam main pipe is discharged outside through the second branch pipe, so that an effective steam discharge path is ensured when the condenser is not available, the reactor is kept to be stopped, the reactor stopping frequency is reduced, an operator has enough time to reduce the reactor power according to the operation rules, and the operation stability, the safety and the reliability of the reactor are greatly improved.

Further, when the decompression and temperature reduction assembly is opened, part of steam is discharged to the auxiliary steam header through the third branch pipe after decompression and temperature reduction to heat water in the deaerator, so that part of steam is recovered to the auxiliary steam header after decompression and temperature reduction for heating and heating general steam of the deaerator, and the like, thereby reducing the load of an auxiliary electric boiler and improving the economy of a power plant.

The reactor power is reduced, after the main steam main pipe steam is converted into saturated steam from superheated steam, the steam-water separator establishes a water level, and the water is drained to the circulating cooling assembly through the second drain valve of the steam-water separator, so that the high-temperature drain water is recycled after being cooled, the working medium loss is greatly reduced, and the low-power operation economy of the power plant is improved.

Drawings

FIG. 1 is a schematic diagram of a low power cycle operation system of a high temperature gas cooled reactor according to an embodiment of the present application.

In the figure: 1. a steam generator; 2. a main steam main pipe; 3. a first branch pipe; 4. first side a road valve; 5. a condenser; 6. a second branch pipe; 7. a discharge valve; 81. a first isolation valve; 82. a second isolation valve; 83. a third isolation valve; 91. a first connection point; 92. a second connection point; 93. a third connection point; 94. a fourth connection point; 95. a fifth connection point; 96. a sixth connection point; 97. a seventh connection point; 10. an auxiliary steam header; 11. a pressure and temperature reducing assembly; 12. a third branch pipe; 13. a desalting water tank; 14. a deaerator; 15. a first condensate make-up pump; 16. a second condensate water supplementing pump; 17. a recirculation pipe; 18. a first water supplementing valve; 19. a second water supplementing valve; 20. an inlet valve; 21. an outlet valve; 22. a second bypass valve; 23. a fifth branch pipe; 24. a sixth branch pipe; 25. a steam-water separator; 26. a first drain valve; 27. a second drain valve; 28. a drain cooler; 291. a cooling water tower; 292. a circulating water pump; 293. a water supply isolation valve; 294. a backwater isolation valve; 30. a hydrophobic tank; 31. a drainage pump; 32. a drainage valve; 33. a water drain valve; 34. a liquid level transmitter; 35. a pressure sensor; 36. and a water supplementing loop.

Detailed Description

Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application unless it is specifically stated otherwise.

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements throughout or elements having like or similar functionality. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The features of the application "first", "second" and the like in the description and in the claims may be used for the explicit or implicit inclusion of one or more such features. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more. Furthermore, in the description and claims, "and/or" means at least one of the connected objects, and the character "/", generally means that the associated object is an "or" relationship.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

According to one aspect of the present application, as shown in fig. 1, there is provided a low power cycle operation system of a high temperature gas cooled reactor, comprising:

the steam generator 1 is connected with the main steam main pipe 2; one end of the first branch pipe 3 is connected with the main steam main pipe 2 and forms a first connection point 91, and the other end is connected with the condenser 5; the first bypass valve 4 is arranged on the first branch pipe 3;

a second branch pipe 6 and a discharge valve 7, wherein one end of the second branch pipe 6 is connected with the main steam mother pipe 2 and forms a second connection point 92, the second connection point 92 is positioned on one side of the first connection point 91 close to the steam generator 1, and the discharge valve 7 is arranged on the second branch pipe 6;

a third branch pipe 12, a pressure-reducing and temperature-reducing assembly 11 and an auxiliary steam header 10, wherein one end of the third branch pipe 12 is connected with the second branch pipe 6 to form a third connection point 93, the third connection point 93 is positioned between the second connection point 92 and the discharge valve 7, the other end of the third branch pipe 12 is connected with the auxiliary steam header 10, and the pressure-reducing and temperature-reducing assembly 11 is arranged on the third branch pipe 12;

when the condenser 5 is not available, the first bypass valve 4 is closed and the discharge valve 7 is opened, and the steam in the main steam main pipe 2 is discharged through the second branch pipe 6; when the pressure-reducing and temperature-reducing assembly 11 is opened, part of steam is discharged to the auxiliary steam header 10 through the third branch pipe 12 after pressure reduction and temperature reduction so as to heat water in the deaerator 14.

In the embodiment of the application, when the condenser 5 is not available, the first bypass valve 4 is closed and the discharge valve 7 is opened, steam in the main steam main pipe 2 is discharged outside through the second branch pipe 6, so that an effective steam discharge path is ensured when the condenser 5 is not available, the reactor is kept to be stopped, the reactor shutdown frequency is reduced, an operator has enough time to reduce the reactor power according to the operation regulations, and the operation of the condenser 5 is attempted to be recovered, and the stability, the safety and the reliability of the operation of the reactor are greatly improved.

Further, when the decompression and temperature reduction assembly 11 is opened, part of steam is discharged to the auxiliary steam header 10 through the third branch pipe 12 after decompression and temperature reduction to heat water in the deaerator 14, so that part of steam is recycled to the auxiliary steam header 10 after decompression and temperature reduction for heating of the deaerator 14, heating of universal steam and the like, thereby reducing the load of an auxiliary electric boiler and improving the economy of a power plant.

Optionally, the low-power cycle operation system of the high-temperature gas cooled reactor further comprises a first isolation valve 81, a second isolation valve 82 and a third isolation valve 83;

the first isolation valve 81 and the second isolation valve 82 are both arranged on the second branch pipe 6, the first isolation valve 81 is positioned between the discharge valve 7 and the second connection point 92, and the second isolation valve 82 is positioned on one side of the discharge valve 7 away from the second connection point 92;

the third isolation valve 83 is disposed in the third branch pipe 12, and the third isolation valve 83 is located between the third connection point 93 and the pressure and temperature reducing assembly 11.

In the above embodiment, the first isolation valve 81 is a front isolation valve of the discharge valve 7, the second isolation valve 82 is a rear isolation valve of the discharge valve 7, and the first isolation valve 81 and the second isolation valve 82 can better isolate the discharge valve 7, so as to facilitate maintenance, maintenance or replacement of the discharge valve 7, and have higher operation safety. The third isolation valve 83 can well isolate the pressure-reducing and temperature-reducing assembly 11, so that the pressure-reducing and temperature-reducing assembly 11 can be maintained, maintained or replaced conveniently, and the operation safety is high.

Optionally, the low-power circulating operation system of the high-temperature gas cooled reactor further comprises a desalting water tank 13, a deaerator 14, a first condensate water supplementing pump 15, a second condensate water supplementing pump 16, a recycling pipe 17, a first water supplementing valve 18 and a second water supplementing valve 19, wherein the desalting water tank 13 is a conventional island desalting water tank 13; the demineralized water tank 13 is connected with the deaerator 14, a first condensate water supplementing pump 15 and a second condensate water supplementing pump 16 are arranged on a connecting pipeline between the demineralized water tank 13 and the deaerator 14, the first condensate water supplementing pump 15 and the second condensate water supplementing pump 16 are connected in parallel and form a fourth connecting point 94 and a fifth connecting point 95, the fourth connecting point 94 is connected with the demineralized water tank 13, and the fifth connecting point 95 is connected with the deaerator 14; a fifth connection point 95 is connected to the desalinated water tank 13 via the recirculation pipe 17, the recirculation pipe 17 providing minimum flow protection for the first condensate make-up pump 15 and the second condensate make-up pump 16;

the first water supplementing valve 18 is arranged on a connecting pipeline between the fifth connecting point 95 and the deaerator 14, and the deaerator 14 is supplemented with condensed water through the first water supplementing valve 18;

the fifth connection point 95 is connected to the pressure-reducing and temperature-reducing assembly 11, and the second water-compensating valve 19 is disposed on a connection line between the fifth connection point 95 and the pressure-reducing and temperature-reducing assembly 11, and the pressure-reducing and temperature-reducing assembly 11 is supplemented with reduced temperature water through the second water-compensating valve 19.

In the above embodiment, the first condensate water supplementing pump 15 is used as a normal water supplementing pump, and the pump design flow is smaller, so as to provide the normal water supplementing and the initial water feeding of the two loops; the second condensate water supplementing pump 16 has a larger pump design flow, and is used for supplying water to the deaerator 14 when the first condensate water supplementing pump 15 is not available, and also can be used for providing the temperature reducing water for the pressure reducing and temperature reducing assembly 11.

The recirculation pipe 17 provides minimum flow protection for the first condensate water make-up pump 15 and the second condensate water make-up pump 16, and the recirculation pipe 17 is provided with a regulating valve by which the flow in the recirculation pipe 17 can be controlled well. The temperature and pressure reducing assembly can be provided with temperature reducing water by adjusting the second water supplementing valve 19, the deaerator 14 can be provided with condensed water by adjusting the first water supplementing valve 18, and the loss of an initial steam discharge medium of the deaerator 14 after the condenser 5 is not available is supplemented; the medium in the desalting water tank 13 is dosing condensed water, the water quality is the same as the condensed water in the condenser 5, and when the water quality in the desalting water tank 13 is unqualified, the water can be purified by a fine treatment system.

Therefore, the first condensate water supplementing pump 15 and the second condensate water supplementing pump 16 have two functions: firstly, providing the temperature reduction water for the pressure reduction and temperature reduction assembly 11, and avoiding the risk of losing the temperature reduction water after the condensate pump of the condenser 5 stops operating; and secondly, condensed water is provided for the deaerator 14, and working medium loss caused by steam discharge is supplemented.

In a specific embodiment, the pressure and temperature reducing assembly 11 comprises a pressure reducing valve and a temperature reducing valve, the temperature reducing valve being arranged between the pressure reducing valve and the auxiliary header 10.

Optionally, the low-power circulation operation system of the high-temperature gas cooled reactor further comprises an inlet valve 20, an outlet valve 21, a second bypass valve 22, a fifth branch pipe 23, a sixth branch pipe 24, a steam-water separator 25, a first drain valve 26, a second drain valve 27 and a drain cooler 28;

one end of the fifth branch pipe 23 is connected with the main steam mother pipe 2 to form a sixth connection point 96, the other end of the fifth branch pipe is connected with the steam-water separator 25, and the inlet regulating valve 20 is arranged on the fifth branch pipe 23; one end of the sixth branch pipe 24 is connected with the steam-water separator 25, the other end of the sixth branch pipe is connected with the main steam main pipe 2 to form a seventh connection point 97, and the second bypass valve 22 is arranged on a connection pipeline between the sixth connection point 96 and the seventh connection point 97; the sixth connection point 96, the seventh connection point 97, the second connection point 92, and the first connection point 91 are sequentially arranged on the main steam header 2 in a direction away from the steam generator 1; a first drain valve 26 is arranged between the steam-water separator 25 and the condenser 5;

the outlet medium of the steam generator 1 can enter the steam-water separator 25 through the fifth branch pipe 23 to be subjected to steam-water separation, steam enters the main steam main pipe 2 through the outlet valve 21, and water enters the condenser 5 through the first drain valve 26; the outlet medium of the steam generator 1 can also be output from the main steam header 2 via the second bypass valve 22;

the steam-water separator 25 is connected with the drain cooler 28, and the second drain valve 27 is arranged between the steam-water separator 25 and the drain cooler 28, and the steam-water separator 25 can drain water to the drain cooler 28 through the second drain valve 27.

In the above embodiment, the inlet valve 20 of the steam-water separator 25 can control the outlet pressure of the steam generator 1 to be at the target value, and the outlet medium of the steam generator 1 can be depressurized and then delivered to the steam-water separator 25. When the outlet medium of the steam generator 1 is superheated steam, the outlet regulating valve 21 of the steam-water separator 25 is closed, and the second bypass valve 22 is opened to output steam from the main steam header 2. When the outlet medium of the steam generator 1 is in a water, saturated state and two-phase flow state, the second bypass valve 22 is closed, and the outlet regulating valve 21 of the steam-water separator 25 is opened, so that steam passing through the steam-water separator 25 is output from the main steam main pipe 2, and the stable operation of the high-temperature gas cooled reactor can be better ensured.

The steam separator 25 is drained by a first drain valve 26 and a second drain valve 27. The first drain valve 26 drains to the condenser 5 when the condenser 5 is available, the first drain valve 26 is closed when the condenser 5 is not available, and the second drain valve 27 is opened, so that working media in the steam-water separator 25 are conveyed to the drain cooler 28 for cooling, heat generated by a reactor core is carried out, and the operation safety of the high-temperature gas cooled reactor is ensured.

Therefore, the steam-water separator 25 is provided with a normal drain circuit (a first drain valve 26) and a critical drain circuit (a second drain valve 27), and under normal and critical working conditions, the normal water level of the steam-water separator 25 is automatically adjusted and maintained according to the liquid level of the steam-water separator 25, so that the risk of full water of the steam-water separator 25 is prevented.

Optionally, the low-power circulating operation system of the high-temperature gas cooled reactor further comprises a circulating cooling assembly and a water supplementing loop 36, wherein the circulating cooling assembly is connected with the drain cooler 28 and is used for cooling drain water in the drain cooler 28;

the water replenishing loop 36 is connected to the recirculating cooling module for replenishing water into the recirculating cooling module.

In the above embodiments, the recirculating cooling assembly is effective to effect cooling of the water within water trap 28. The water supplementing loop 36 can timely supplement water into the circulating cooling assembly, and the cooling effect of the circulating cooling assembly is guaranteed.

Optionally, the circulating cooling assembly includes a cooling water tower 291, a circulating water pump 292, a water supply isolation valve 293 and a return water isolation valve 294;

a circulating water pump 292 and a water supply isolation valve 293 are arranged on the water supply pipelines of the cooling water tower 291 and the drain cooler 28, and the water supply isolation valve 293 is positioned on one side of the circulating water pump 292 close to the drain cooler 28;

the return water isolation valve 294 is provided on the return water line of the cooling water tower 291 and the drain cooler 28.

Specifically, the shell side of the drain cooler 28 flows through the drain from the steam-water separator 25, the tube side flows through the circulating cooling water from the circulating cooling assembly, the heat carried by the drain from the steam-water separator 25 is transferred to the circulating cooling water by heat exchange, and the circulating cooling water transfers the heat to the final hot well atmosphere by natural circulation in the cooling water tower 291.

In the above embodiment, the circulating water pump 292 drives the circulating cooling water to circulate between the drain cooler 28 and the cooling water tower 291 to provide a desired circulating cooling water head, the circulating water pump 292 is a variable frequency pump, the supply flow rate is controlled according to the target value of the outlet temperature of the drain cooler 28, and the lower the outlet temperature of the drain cooler 28 is, the larger the flow rate of the circulating water pump 292 is required. The water supply isolation valve 293 can effectively control the opening or closing of the water supply loop, and the backwater isolation valve 294 can effectively control the opening or closing of the backwater loop, so that the operation is very simple. The make-up circuit 36 uses industrial water provided by the industrial water system in the factory as make-up water for the circulating cooling water to compensate for water loss of the cooling water tower 291 during heat exchange.

Therefore, the outlet drain temperature of the drain cooler 28 can be adjusted according to the feed water temperature of the deaerator 14, and the cooled drain directly enters the deaerator 14 for circulation, so that auxiliary steam is not needed for heating, the electric boiler power in the operation mode is greatly reduced, and the operation cost is reduced.

Optionally, the low-power circulation operation system of the high-temperature gas cooled reactor further comprises a drain tank 30, wherein the drain tank 30 is connected with the drain cooler 28 and is used for collecting drain cooled by the drain cooler 28.

In the above embodiment, the drain water cooled by the drain cooler 28 is collected in the drain tank 30, so that the cooled drain water can be stably collected.

It should be noted that, the drain cooler 28 may be used as a backup for the condenser 5, and provides a low-power stage cooling method when the condenser 5 is not available, and establishes a cycle in the start-up stage to conduct heat of the reactor core, so as to maintain the low-power refueling operation of the reactor.

Optionally, the low-power circulating operation system of the high-temperature gas cooled reactor further comprises a drainage pump 31 and a drainage valve 32;

the drain tank 30 is connected with the deaerator 14, a drain pump 31 and a drain valve 32 are arranged on a connecting pipeline of the drain tank 30 and the deaerator 14, and the drain valve 32 is positioned on one side of the drain valve 32 close to the deaerator 14.

In the above embodiment, the drain tank 30 collects the drain water cooled by the drain cooler 28, and then drains the drain water to the deaerator 14 through the drain pump 31 to establish a circulation, wherein the drain valve 32 is used for adjusting the drain water flow rate delivered to the deaerator 14, so that the operation is convenient. The opening of the drain regulator 32 is affected by the level of the deaerator 14 to maintain the level of the deaerator 14 stable.

Therefore, after the power of the reactor is reduced, the steam-water separator 25 and the drain cooler 28 are put into the reactor, the heat of the reactor core is carried out by the drain cooler 28, and the outlet medium of the steam generator 1 is cooled and recycled, so that the discharge is reduced, the working medium loss is reduced, and the economy is improved.

Optionally, the low-power circulating operation system of the high-temperature gas cooled reactor further comprises a water drain valve 33 and a liquid level transmitter 34;

the drain valve 33 and the liquid level transmitter 34 are respectively connected with the drain tank 30, and drain water in the drain tank 30 can be discharged through the drain valve 33;

the liquid level transmitter 34 is used for controlling the liquid level in the drain tank 30 to be a preset value through the drain valve 33.

In the above embodiments, drain valve 33 and level transmitter 34 help to maintain a stable level of liquid within hydrophobic tank 30. The drain tank 30 collects the cooled drain water, the drain pump 31 conveys the drain water to the deaerator 14 to participate in the two-circuit circulation, the liquid level of the drain tank 30 is automatically maintained at a normal level by the drain valve 33 arranged at the bottom, and the drain water is discharged to the two-circuit monitoring drain pool.

Optionally, the low-power cycle operation system of the high-temperature gas cooled reactor further comprises a pressure sensor 35, wherein the pressure sensor 35 is arranged on the main steam mother pipe 2, and the pressure sensor 35 is positioned between the seventh connection point 97 and the second connection point 92.

In the above embodiment, the opening degree of the drain valve 7 is controlled based on the measurement data of the pressure sensor 35, so that the pressure of the main steam header 2 can be maintained within the set value range, and the safe and stable operation of the steam generator 1 can be ensured.

In the embodiment of the application, the low-power circulating operation system of the high-temperature gas cooled reactor ensures that when the high-temperature gas cooled reactor is unavailable in the first bypass valve 4 or the condenser 5, the steam generated by the reactor is firstly discharged in a controllable way, the reactor is maintained to be not shut down, after the power of the reactor is reduced, the two-phase flow working medium at the outlet of the steam generator 1 is separated from water in the water-steam separator 25, and then the core heat is carried out through the drain cooler 28, so that the working medium is recycled, and the low-power refueling operation without shut down is maintained.

A second branch pipe 6 for discharging air controllably is added on the main steam main pipe 2 in front of the first bypass valve 4 of the steam turbine, a discharge valve 7 for discharging critical steam controllably is arranged on the second branch pipe 6, a first isolation valve 81 is arranged on the upstream of the discharge valve 7, and the steam turbine is in an open state during normal operation. A second isolation valve 82 is arranged downstream of the discharge valve 7 and is normally closed. The second branch pipe 6 is used for opening the second isolation valve 82 when the first bypass valve 4 of the steam turbine is unavailable or the condenser 5 cannot receive steam, the discharge valve 7 automatically and controllably discharges according to the pressure of the main steam main pipe 2, so as to strive for time for operators to reduce the power of the reactor, and simultaneously recover the two-loop cold source system or load the low-power refueling operation heat of the reactor out of the circulation operation system for operation.

A third branch pipe 12 is led out between the discharge valve 7 and the first isolation valve 81, is decompressed and cooled, and is supplied to the auxiliary steam header 10 for heating, ventilation, steam supply and the like of the deaerator 14. The desuperheating water is supplied by a conventional island condensation water make-up pump. The main function of the loop is to reduce the steam discharge and recycle a part of the steam for heating the water supply.

In addition, a reactor low-power refueling operation heat carrying-out circulation operation subsystem is added. The subsystem is arranged downstream of the second drain valve 27 of the steam-water separator 25, comprising a drain cooler 28, a circulating water pump 292 and a cooling water tower 291. The circulated cooling water cools the drain water outputted from the steam-water separator 25 through the drain cooler 28, and finally discharges the reactor heat to the atmosphere through the cooling water tower 291. The recirculated cooling water cools the drain water at the outlet of the steam-water separator 25 from 260 ℃ to below 100 ℃ through the drain cooler 28, and then is recovered to the deaerator 14 for recycling. In normal conditions, the steam-water separator 25 is used for draining water to a drainage expansion vessel of the condenser 5 through the first drain valve 26; when the condenser 5 is not available, the first drain valve 26 of the steam-water separator 25 is closed, the second drain valve 27 is opened, critical drain water sequentially passes through the drain cooler 28, cooled critical drain water is conveyed to the drain tank 30 and then pumped to the deaerator 14 through the drain pump 31, and circulation is established. The medium within the charge air cooler 28 is cooled by a recirculating cooling assembly, the recirculating cooling water rejecting heat to the atmosphere in a cooling tower 291. The cooling water tower 291 is supplied with water by a factory living water system.

The operation mode of the low-power circulating operation system of the high-temperature gas cooled reactor is as follows:

the reactor is in the normal power operation phase: when the reactor is in power operation, a transient state occurs, the first bypass valve 4 or the condenser 5 is not available, and at the moment, the steam turbine is in emergency stop (if the steam turbine is in operation), the pressure of the main steam main pipe 2 is increased, the discharge valve 7 is opened for discharging air, and the pressure of the main steam main pipe 2 is maintained at a target value. The reactor operator performs an emergency power reduction operation to shut down the condensate pump (to prevent cavitation damage due to high condenser 5 inlet temperature), and the water source for the deaerator 14 is provided by a conventional island demineralized water tank 13 and a first condensate make-up pump 15 and a second condensate make-up pump 16, avoiding an interlock shut-down feed pump with a too low deaerator 14 level.

The heated air source of the deaerator 14 is supplied by steam which passes through the discharge valve 7 and the pressure-reducing and temperature-reducing assembly 11 in sequence. When the power of the reactor is reduced below 50MW and the main water supply flow is reduced to about 25kg/s, the outlet steam of the steam generator 1 enters a two-phase flow stage, the two-phase flow stage is put into the steam-water separator 25, the pressure of the steam-water separator 25 is controlled to be about 5MPa by the second drain valve 27, the drain water leads heat to the atmosphere through the drain water cooler 28 and the circulating cooling assembly, and the cooled drain water is collected in the drain water tank 30 and then is recovered to the deaerator 14 through the drain water pump 31.

In addition, the low-power circulating operation system of the high-temperature gas cooled reactor can also be used for leading out the heat of the reactor core in the starting stage of the reactor.

During the reactor start-up phase: the low-power circulation operation system of the high-temperature gas cooled reactor can be put into, and a circulation loop of the deaerator 14, the feed pump, the steam generator 1 (reactor), the steam-water separator 25, the drain cooler 28, the cooling water tower 291 and the deaerator 14 is established. Starting, the deaerator 14 is supplied by the auxiliary electric boiler to heat steam, and the water supply temperature is increased to meet the water supply temperature requirement of the steam generator 1. After the reactor is critical, as the reactor power increases, the outlet temperature of the steam generator 1 gradually increases, hot water enters the drain cooler 28 through the steam-water separator 25, and heat is transferred to the circulating cooling assembly in the drain cooler 28 to be transferred to the cooling tower for heat exchange. The cooled drain water returns to deaerator 14. As the power of the reactor increases, the pressure of the steam-water separator 25 gradually increases to 5MPa, and after increasing to 5MPa, the first isolation valve 81 is opened, and the steam is supplied to the auxiliary steam header 10 after being depressurized and cooled, so as to reduce the output of the electric boiler. And as the power of the reactor is further increased, switching to normal loop operation, and exiting the high-temperature gas cooled reactor low-power circulating operation system.

It is to be understood that the above embodiments are merely illustrative of the application of the principles of the present application, but not in limitation thereof. Various modifications and improvements may be made by those skilled in the art without departing from the spirit and substance of the application, and are also considered to be within the scope of the application.

Claims (10)

1. A high temperature gas cooled reactor low power cycle operating system comprising:

the device comprises a steam generator, a main steam main pipe, a first branch pipe, a first bypass valve and a condenser, wherein the steam generator is connected with the main steam main pipe; one end of the first branch pipe is connected with the main steam main pipe and forms a first connecting point, and the other end of the first branch pipe is connected with the condenser; the first bypass valve is arranged on the first branch pipe;

the second branch pipe is connected with the main steam main pipe at one end and forms a second connection point, the second connection point is positioned at one side of the first connection point, which is close to the steam generator, and the discharge valve is arranged on the second branch pipe;

the system comprises a third branch pipe, a pressure-reducing and temperature-reducing assembly and an auxiliary steam header, wherein one end of the third branch pipe is connected with the second branch pipe to form a third connecting point, the third connecting point is positioned between the second connecting point and the discharge valve, the other end of the third branch pipe is connected with the auxiliary steam header, and the pressure-reducing and temperature-reducing assembly is arranged on the third branch pipe;

when the condenser is not available, closing the first bypass valve and opening the discharge valve, and discharging steam in the main steam main pipe through the second branch pipe; when the decompression and temperature reduction assembly is opened, part of steam is discharged to the auxiliary steam header through the third branch pipe after decompression and temperature reduction so as to heat water in the deaerator.

2. The high temperature gas cooled reactor low power cycle operation system of claim 1, further comprising a first isolation valve, a second isolation valve, and a third isolation valve;

the first isolation valve and the second isolation valve are both arranged on the second branch pipe, the first isolation valve is positioned between the discharge valve and the second connection point, and the second isolation valve is positioned on one side of the discharge valve away from the second connection point;

the third isolation valve is arranged on the third branch pipe, and the third isolation valve is positioned between the third connection point and the pressure-reducing and temperature-reducing component.

3. The low power cycle operation system of a high temperature gas cooled reactor according to claim 2, further comprising a desalination tank, a deaerator, a first condensate make-up water pump, a second condensate make-up water pump, a recirculation pipe, a first make-up water valve, and a second make-up water valve; the desalination water tank is connected with the deaerator, a first condensate water supplementing pump and a second condensate water supplementing pump are arranged on a connecting pipeline between the desalination water tank and the deaerator, the first condensate water supplementing pump and the second condensate water supplementing pump are connected in parallel and form a fourth connecting point and a fifth connecting point, the fourth connecting point is connected with the desalination water tank, and the fifth connecting point is connected with the deaerator; the fifth connecting point is connected with the demineralized water tank through the recycling pipe, and the recycling pipe provides minimum flow protection for the first condensate water supplementing pump and the second condensate water supplementing pump;

the first water supplementing valve is arranged on a connecting pipeline between the fifth connecting point and the deaerator, and is used for supplementing condensation water to the deaerator;

the fifth connecting point is connected with the pressure-reducing and temperature-reducing assembly, the second water supplementing valve is arranged on the connecting pipeline of the fifth connecting point and the pressure-reducing and temperature-reducing assembly, and the pressure-reducing and temperature-reducing water is supplemented into the pressure-reducing and temperature-reducing assembly through the second water supplementing valve.

4. The low power cycle operation system of a high temperature gas cooled reactor according to claim 3, further comprising an inlet valve, an outlet valve, a second bypass valve, a fifth branch pipe, a sixth branch pipe, a steam-water separator, a first trap, a second trap, and a trap;

one end of the fifth branch pipe is connected with the main steam main pipe to form a sixth connection point, the other end of the fifth branch pipe is connected with the steam-water separator, and the inlet regulating valve is arranged on the fifth branch pipe; one end of the sixth branch pipe is connected with the steam-water separator, the other end of the sixth branch pipe is connected with the main steam main pipe to form a seventh connection point, and the second bypass valve is arranged on a connection pipeline between the sixth connection point and the seventh connection point; the sixth connecting point, the seventh connecting point, the second connecting point and the first connecting point are sequentially arranged on the main steam main pipe along the direction away from the steam generator; a first drain valve is arranged between the steam-water separator and the condenser;

the outlet medium of the steam generator can enter the steam-water separator through the fifth branch pipe to be subjected to steam-water separation, steam enters the main steam main pipe through the outlet valve, and water enters the condenser through the first drain valve; the outlet medium of the steam generator can be output by the main steam main pipe through the second bypass valve;

the steam-water separator is connected with the drain cooler, the second drain valve is arranged between the steam-water separator and the drain cooler, and the steam-water separator can drain water to the drain cooler through the second drain valve.

5. The low power circulating operation system of high temperature gas cooled reactor according to claim 4, further comprising a circulating cooling assembly and a water supplementing loop, wherein the circulating cooling assembly is connected with the drain cooler and is used for cooling drain water in the drain cooler;

the water supplementing loop is connected with the circulating cooling assembly and used for supplementing water into the circulating cooling assembly.

6. The low power circulating operation system of high temperature gas cooled reactor according to claim 5, wherein the circulating cooling assembly comprises a cooling water tower, a circulating water pump, a water supply isolation valve and a return water isolation valve;

a circulating water pump and a water supply isolation valve are arranged on the water supply pipelines of the cooling water tower and the drain cooler, and the water supply isolation valve is positioned on one side of the circulating water pump, which is close to the drain cooler;

and the return water isolation valve is arranged on the return water pipelines of the cooling water tower and the drain cooler.

7. The low power cycle operation system of a high temperature gas cooled reactor according to claim 6, further comprising a hydrophobic tank coupled to said hydrophobic radiator for collecting hydrophobic water cooled by said hydrophobic radiator.

8. The low power cycle operation system of a high temperature gas cooled reactor according to claim 7, further comprising a drain pump and a drain valve;

the drainage box is connected with the deaerator, the drainage pump and the drainage valve are arranged on the connecting pipeline of the drainage box and the deaerator, and the drainage valve is positioned on one side of the drainage valve close to the deaerator.

9. The low power cycle operation system of a high temperature gas cooled reactor according to claim 8, further comprising a drain valve and a level transmitter;

the drain valve and the liquid level transmitter are respectively connected with the drain tank, and drain water in the drain tank can be discharged through the drain valve;

the liquid level transmitter is used for controlling the liquid level in the hydrophobic tank to be a preset value through a water drain valve.

10. The low power cycle operation system of a high temperature gas cooled reactor according to claim 9, further comprising a pressure sensor disposed in the main steam header and located between the seventh connection point and the second connection point.