Peak shaving system based on fused salt heat storage coupling nuclear power

Abstract

The utility model provides a peak shaving system based on fused salt heat storage coupling nuclear power. The peak shaving system comprises a nuclear reaction steam unit, a first steam turbine, a first power generator, a second steam turbine, a second power generator, a fused salt heat storage assembly and a fused salt electric heater. The nuclear reaction steam unit provides steam for the first steam turbine, the first steam turbine drives the first power generator, and when the power generation load requirement is low, the fused salt heat storage assembly absorbs heat of part of steam generated by the nuclear reaction steam unit through low-temperature fused salt, converts the heat into medium-temperature fused salt and stores the medium-temperature fused salt; the molten salt electric heater reheats the medium-temperature molten salt to obtain high-temperature molten salt; surplus electric quantity is reasonably utilized to further increase the molten salt temperature, and waste of steam and electric quantity is avoided; when the power generation load demand is high, the high-temperature fused salt exchanges heat with part of return water discharged by the first steam turbine, and steam is obtained and provided for the second steam turbine; the change of peak and valley power utilization can be met, the generating capacity of the nuclear power unit can be flexibly adjusted, and energy waste is avoided.

Description

Technical Field

[0001] The present application belongs to the technical field of new energy and energy conservation, and in particular, relates to a peak regulation system based on molten salt heat storage coupled with nuclear power. Background Art

[0002] With the increase in the scale of new energy and the continuous widening of the peak-to-valley difference in electricity consumption, the difficulty of ensuring the supply and demand balance of the power system is becoming increasingly prominent. After a large number of flexibility modifications have been made to thermal power units, the peak-shaving space of nuclear power units also needs to be considered.

[0003] As a good heat carrier, molten salt has the advantages of large heat capacity, high heat transfer efficiency, good chemical stability, low operating pressure and relatively low price. It has been widely used in solar thermal power stations, chemical production and other fields.

[0004] How to utilize the heat storage and release functions of molten salt to flexibly adjust the power generation of nuclear power units has become a concern for technicians. Utility Model Content

[0005] To solve the above technical problems, according to some embodiments, the present application provides a peak-shaving system based on molten salt heat storage coupled nuclear power, which is applicable to a nuclear power unit, wherein the nuclear power unit has a nuclear reaction steam unit, a first steam turbine and a first generator, wherein the nuclear reaction steam unit provides steam for the first steam turbine, and the first steam turbine drives the first generator, including: a second steam turbine, a second generator, a molten salt heat storage component and a molten salt electric heater;

[0006] When the power generation load demand is low, the molten salt heat storage component uses low-temperature molten salt to absorb the heat of part of the steam generated by the nuclear reaction steam unit and converts it into medium-temperature molten salt; the molten salt electric heater can be used to heat the high-temperature molten salt again to obtain high-temperature molten salt and store it;

[0007] When the power generation load demand is high, the molten salt heat storage component exchanges heat between the high-temperature molten salt and part of the return water / reflux steam discharged from the first steam turbine, converts it into high-temperature steam and provides it to the second steam turbine. The second steam turbine drives the second generator, and the rated power of the second generator is less than that of the first generator.

[0008] Furthermore, the molten salt heat storage assembly comprises a high-temperature molten salt tank, a low-temperature molten salt tank and a steam molten salt heat exchanger;

[0009] The high-temperature molten salt tank is used to store high-temperature molten salt, the low-temperature molten salt tank is used to store low-temperature molten salt, and the steam molten salt heat exchanger is used to absorb part of the heat of the steam generated by the nuclear reaction steam unit using low-temperature molten salt.

[0010] Furthermore, the molten salt heat storage assembly also has a superheater, an evaporator and a preheater;

[0011] When the power generation load demand is high, the high-temperature molten salt in the high-temperature molten salt tank releases heat through the superheater, evaporator and preheater in turn, and part of the return water of the first steam turbine absorbs the heat of the high-temperature molten salt through the preheater, evaporator and superheater in turn to obtain high-temperature steam and provide it to the second steam turbine, and the obtained low-temperature molten salt is stored in the low-temperature molten salt tank.

[0012] Furthermore, the first steam turbine and the nuclear reaction steam unit form a feed water loop, and a condenser, a condensate pump, a low-pressure heater, a deaerator, a feed water pump and a high-pressure heater are sequentially arranged downstream of the steam outlet of the first steam turbine.

[0013] Furthermore, part of the return water of the first steam turbine used for absorbing the heat of the high-temperature molten salt is deoxygenated water that has passed through the deaerator.

[0014] Furthermore, a small water supply pump is provided on the pipeline of deoxygenated water for absorbing the heat of the high-temperature molten salt.

[0015] Furthermore, the nuclear reaction steam unit includes a nuclear reactor and a heat exchanger.

[0016] Furthermore, a steam valve is provided between the nuclear reaction steam unit and the steam inlet of the steam molten salt heat exchanger.

[0017] Further, the return steam of the second steam turbine is merged into the return steam of the first steam turbine.

[0018] Furthermore, the condensed water or steam obtained by heat exchange in the steam molten salt heat exchanger passes through a deaerator and is then incorporated into the feed water circuit of the first steam turbine.

[0019] The above technical solution of the utility model has at least the following beneficial technical effects:

[0020] When the power generation load demand is low, the molten salt electric heater can be used to heat the high-temperature molten salt again; preferably, the electricity used by the molten salt electric heater comes from the first generator, so that when the power load demand is low, a part of the heat is first stored in the molten salt, and the surplus electricity produced is reasonably used to further increase the molten salt temperature, avoiding waste of steam and electricity while storing heat in the molten salt for backup; when the nuclear reaction steam unit, the first steam turbine and the first generator are all under high load and still cannot meet the electricity demand, the heat of the high-temperature molten salt is released, and the steam obtained by heat exchange drives the second steam turbine and the second generator to generate electricity, which can meet the changes in electricity peaks and troughs, and flexibly adjust the power generation of the nuclear power unit to avoid energy waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a structural schematic diagram of a peak-shaving system based on molten salt heat storage coupled with nuclear power in one embodiment of the present application.

[0023] The accompanying drawings are marked as follows:

[0024] 1. Nuclear reactor; 2. Heat exchanger; 3. First steam turbine; 4. First generator; 5. Condenser; 6. Condensate pump; 7. Low-pressure heater; 8. Deaerator; 9. Feedwater pump; 10. High-pressure heater; 11. Steam valve; 12. Steam molten salt heat exchanger; 13. Low-temperature molten salt tank; 14. High-temperature molten salt tank; 15. Low-temperature molten salt pump; 16. High-temperature molten salt pump; 17. Molten salt electric heater; 18. Small feedwater pump; 19. Preheater; 20. Evaporator; 21. Superheater; 22. Second steam turbine; 23. Second generator; DETAILED DESCRIPTION

[0025] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. However, it will be appreciated by those skilled in the art that in the embodiments of the present application, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can also be implemented. The division of the following embodiments is for the convenience of description, and the specific implementation of the present application should not be construed as any limitation, and the various embodiments can be combined with each other and quoted from each other without contradiction.

[0026] The existing nuclear power system uses the heat generated by the nuclear reactor 1 to convert water into high-temperature and high-pressure steam, which is provided to the steam turbine to drive the generator to generate electricity. However, the heat generated by the nuclear reactor 1 and the power generation demand, as well as the power generation and power consumption cannot be matched at any time. The nuclear power system lacks a flexible way to adapt to the peak demand for electricity consumption or power generation.

[0027] To solve the above problems, some embodiments of the present application provide a peak-shaving system based on molten salt heat storage coupled nuclear power, which is applicable to a nuclear power unit, wherein the nuclear power unit has a nuclear reaction steam unit, a first steam turbine 3 and a first generator 4, and the nuclear reaction steam unit provides steam for the first steam turbine 3 to drive the first engine 4; Figure 1As shown, the peak load regulation system in this embodiment further includes a second steam turbine 22, a second generator 23, a molten salt heat storage component and a molten salt electric heater 17;

[0028] When the power generation load demand is low, the molten salt heat storage component uses low-temperature molten salt to absorb the heat of part of the steam produced by the nuclear reaction steam unit and converts it into medium-temperature molten salt; the molten salt electric heater 17 can be used to heat the high-temperature molten salt again to obtain high-temperature molten salt and store it; preferably, the electricity used by the molten salt electric heater 17 comes from the first generator 4, so that when the power load demand is low, a part of the heat is first stored in the molten salt, and the surplus electricity produced by the first generator 4 is reasonably used to further increase the molten salt temperature, thereby avoiding steam and electricity waste and storing heat in the molten salt for backup.

[0029] When the power generation load demand is high, the molten salt heat storage component exchanges heat between the high-temperature molten salt and part of the return water / reflux steam discharged from the first steam turbine 3, converts it into high-temperature steam and provides it to the second steam turbine 22, and the second steam turbine 22 drives the second generator 23 to generate electricity, and the rated power of the second generator 23 is less than that of the first generator 4. In this way, when the nuclear reaction steam unit, the first steam turbine 3 and the first generator 4 are all under high load and still cannot meet the power demand, the steam obtained by heat exchange by releasing the heat of the high-temperature molten salt drives the second steam turbine 22. It can meet the changes in peak and valley of power generation or power consumption, flexibly adjust the power generation of the nuclear power unit and avoid energy waste.

[0030] The molten salt heat storage component has a high-temperature molten salt tank 14, a low-temperature molten salt tank 13 and a steam molten salt heat exchanger 12. The steam molten salt heat exchanger 12 is used to absorb the heat of part of the steam generated by the nuclear reaction steam unit using low-temperature molten salt; the low-temperature molten salt is stored in the low-temperature molten salt tank 13, and the low-temperature molten salt is converted into medium-temperature molten salt after heat exchange with steam. The medium-temperature molten salt is heated again by the molten salt electric heater 17 to obtain high-temperature molten salt and stored in the high-temperature molten salt tank 14; the high-temperature molten salt exchanges heat with part of the return water discharged from the first steam turbine 3, and is converted into low-temperature molten salt and flows back to the low-temperature molten salt tank 13 for storage. The low-temperature molten salt tank 13 is equipped with a low-temperature molten salt pump 15, and the high-temperature molten salt tank 14 is equipped with a high-temperature molten salt pump 16.

[0031] In some embodiments, the molten salt heat storage component also has a superheater 21, an evaporator 20 and a preheater 19, which are used to release the heat of the high-temperature molten salt and exchange heat with the return water of the first steam turbine 3. This embodiment adopts a reverse heat exchange method, that is, the high-temperature molten salt and the return water of the first steam turbine 3 pass through the superheater 21, the evaporator 20 and the preheater 19 in reverse order; the high-temperature molten salt releases heat in the superheater 21, the evaporator 20 and the preheater 19 in turn to be converted into low-temperature lava, and the return water is converted into steam in the preheater 19, the evaporator 20 and the superheater 21 in turn, and the temperature is increased in a gradient, so that the higher temperature molten salt exchanges heat with the higher temperature steam, and the lower temperature molten salt exchanges heat with the lower temperature steam or return water, thereby improving the heat exchange efficiency.

[0032] The first steam turbine 3 and the nuclear reaction steam unit form a feed water loop. The reflux steam at the steam outlet of the first steam turbine 3 itself has a relatively high pressure, and first passes through the condenser 5 to condense into condensate. The return water of the aforementioned first steam turbine is the condensate. The condensate passes through the condensate pump 6, the low-pressure heater 7, the deaerator 8, the feed water pump 9 and the high-pressure heater 10, and finally flows back to the nuclear reaction steam unit to form a cycle.

[0033] In some embodiments, the return water or reflux steam of the first steam turbine 3 may be used for heat exchange with the high-temperature molten salt. Preferably, the return water of the first steam turbine 3 is deoxygenated water obtained by passing through the deaerator 8. When the power load demand is high, a part of the deoxygenated water is heat exchanged with the high-temperature molten salt to be converted into steam and provided to the second steam turbine 22, and the remaining deoxygenated water directly flows back to the nuclear reaction steam unit to participate in the circulation. Furthermore, a small feed water pump 18 is provided on the pipeline of the deoxygenated water used to absorb the heat of the high-temperature molten salt.

[0034] In some embodiments, the nuclear reaction steam unit includes a nuclear reactor 1 and a heat exchanger 2. A steam valve 11 is provided between the steam outlet of the heat exchanger 2 and the steam inlet of the steam molten salt heat exchanger 12 to adjust the flow of the steam used for heat exchange.

[0035] Preferably, the return steam of the second steam turbine 22 is merged into the return steam of the first steam turbine 3 to participate in the circulation.

[0036] Preferably, after heat exchange in the steam molten salt heat exchanger 12 , the condensed water or steam obtained is deoxygenated by the deaerator 8 and then incorporated into the feed water circuit of the first steam turbine 3 .

[0037] In addition, the peak-shaving system of the present application also has multiple pipelines and circuits connecting or communicating various components or members to achieve the circulation of steam, water or molten salt in the manner described in the above technical solution, and valves can be set on the pipelines.

[0038] It should be understood that the above specific embodiments of the present application are only used to illustrate or explain the principles of the present application, and do not constitute a limitation to the present application. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present application should be included in the protection scope of the present application. In addition, the claims attached to the present application are intended to cover all changes and modifications that fall within the scope and boundaries of the attached claims, or the equivalent forms of such scope and boundaries.

Claims

1. A peak load regulation system based on molten salt heat storage coupled nuclear power, applicable to a nuclear power unit, wherein the nuclear power unit comprises a nuclear reaction steam unit, a first steam turbine (3) and a first generator (4), wherein the nuclear reaction steam unit provides steam for the first steam turbine (3), and the first steam turbine (3) drives the first generator (4), characterized in that: include: A second steam turbine (22), a second generator (23), a molten salt heat storage component and a molten salt electric heater (17); When the power generation load demand is low, the molten salt heat storage component uses low-temperature molten salt to absorb the heat of part of the steam generated by the nuclear reaction steam unit and converts it into medium-temperature molten salt; the molten salt electric heater (17) can be used to heat the medium-temperature molten salt again to obtain high-temperature molten salt and store it; When the power generation load demand is high, the molten salt heat storage component exchanges heat between the high-temperature molten salt and part of the return water / return steam discharged from the first steam turbine (3), converts the heat into high-temperature steam and provides it to the second steam turbine (22). The second steam turbine (22) drives the second generator (23), and the rated power of the second generator (23) is less than that of the first generator (4).

2. The system according to claim 1, characterized in that The molten salt heat storage component comprises a high-temperature molten salt tank (14), a low-temperature molten salt tank (13) and a steam molten salt heat exchanger (12); The high-temperature molten salt tank (14) is used to store high-temperature molten salt, the low-temperature molten salt tank (13) is used to store low-temperature molten salt, and the steam molten salt heat exchanger (12) is used to absorb heat of part of the steam generated by the nuclear reaction steam unit using low-temperature molten salt.

3. The system according to claim 2, characterized in that The molten salt heat storage component also has a superheater (21), an evaporator (20) and a preheater (19); When the power generation load demand is high, the high-temperature molten salt in the high-temperature molten salt tank (14) releases heat in turn through the superheater (21), the evaporator (20) and the preheater (19), and part of the return water of the first steam turbine (3) absorbs the heat of the high-temperature molten salt in turn through the preheater (19), the evaporator (20) and the superheater (21), obtains high-temperature steam and provides it to the second steam turbine (22), and the obtained low-temperature molten salt is stored in the low-temperature molten salt tank (13).

4. The system according to claim 2, characterized in that The first steam turbine (3) and the nuclear reaction steam unit form a feed water loop, and a condenser (5), a condensate pump (6), a low-pressure heater (7), a deaerator (8), a feed water pump (9) and a high-pressure heater (10) are sequentially arranged downstream of the steam outlet of the first steam turbine (3).

5. The system according to claim 4, characterized in that Part of the return water of the first steam turbine (3) used to absorb the heat of the high-temperature molten salt is deoxygenated water that has passed through the deaerator (8).

6. The system according to claim 5, characterized in that A small water supply pump (18) is provided on the pipeline of deoxygenated water for absorbing the heat of the high-temperature molten salt.

7. The system according to claim 1, characterized in that The nuclear reaction steam unit comprises a nuclear reactor (1) and a heat exchanger (2).

8. The system according to claim 2, characterized in that A steam valve (11) is provided between the nuclear reaction steam unit and the steam inlet of the steam molten salt heat exchanger (12).

9. The system according to claim 1, characterized in that The return steam of the second steam turbine (22) is merged into the return steam of the first steam turbine (3).

10. The system according to claim 4, characterized in that The condensed water or steam exchanged with the steam molten salt heat exchanger (12) passes through the deaerator (8) and is then incorporated into the feed water circuit of the first steam turbine (3).

Images