A nuclear power generation steam supply system and its usage method

Abstract

This application belongs to the field of nuclear power technology, and particularly relates to a nuclear power generation steam supply system and a method for using the same. The nuclear power generation steam supply system includes a sodium-cooled fast reactor, an intermediate heat exchanger, a secondary sodium pump, a sodium-molten salt heat exchanger, a low-temperature molten salt transfer pump, a first regulating valve, a low-temperature molten salt tank, a high-temperature molten salt tank, a second regulating valve, a high-temperature molten salt transfer pump, a molten salt-water heat exchanger, a steam circuit control valve, a power generation circuit control valve, a superheater, a main feed water pump, a steam turbine generator, a check valve, and a condenser. This application adopts a sodium-sodium-molten salt-water four-loop design to solve the problems that the existing fast reactor adopts a sodium-sodium-water three-loop design, which has not eliminated the possibility of sodium-water reaction and does not have the ability to regulate peak load and frequency modulation.

Description

Technical Field

[0001] This application belongs to the field of nuclear power technology, and particularly relates to a nuclear power generation steam supply system and its usage method. Background Art

[0002] Currently, the existing nuclear power plants do not have the capabilities of peak shaving and frequency modulation. For traditional frequency modulation and peak shaving, the output of the unit is sacrificed. Although part of the cost is compensated by the frequency modulation and peak shaving electricity price subsidies, the economic value of the wasted reactor power is objective for long-term participation in frequency modulation and peak shaving.

[0003] In addition, the fast reactor, as the main reactor type of the fourth generation of nuclear power, represents the future development direction of nuclear power. However, currently, the fast reactor adopts a sodium-sodium-water three-loop design, and the possibility of sodium-water reaction has not been eliminated. Summary of the Invention

[0004] In view of this, this application is committed to providing a nuclear power generation steam supply system and its usage method. By adopting a sodium-sodium-molten salt-water four-loop design, it aims to solve the problems that the existing fast reactor adopts a sodium-sodium-water three-loop design, the possibility of sodium-water reaction has not been eliminated, and it does not have the capabilities of peak shaving and frequency modulation.

[0005] In the first aspect of this application, a nuclear power generation steam supply system is provided. The nuclear power generation steam supply system includes a sodium-cooled fast reactor, an intermediate heat exchanger, a secondary sodium pump, a sodium-molten salt heat exchanger, a low-temperature molten salt transfer pump, a first regulating valve, a low-temperature molten salt tank, a high-temperature molten salt tank, a second regulating valve, a high-temperature molten salt transfer pump, a molten salt-water heat exchanger, a steam circuit control valve, a power generation circuit control valve, a superheater, a main feed water pump, a steam turbine generator, a check valve, and a condenser. The intermediate heat exchanger is immersed in the sodium pool of the sodium-cooled fast reactor. The secondary sodium pump is connected in series between the outlet end of the intermediate heat exchanger and the inlet end of the sodium side of the sodium-molten salt heat exchanger. The inlet end of the intermediate heat exchanger is connected to the outlet end of the sodium side of the sodium-molten salt heat exchanger. The outlet end of the molten salt fluid side of the sodium-molten salt heat exchanger is connected in series with the high-temperature molten salt tank, the second regulating valve, the high-temperature molten salt transfer pump, and the inlet end of the molten salt fluid side of the molten salt-water heat exchanger. The inlet end of the molten salt fluid side of the sodium-molten salt heat exchanger is connected in series with the low-temperature molten salt transfer pump, the first regulating valve, the low-temperature molten salt tank, and the outlet end of the molten salt fluid side of the molten salt-water heat exchanger. The outlet end of the water side of the molten salt-water heat exchanger is connected in series with the power generation circuit control valve, the superheater, the steam turbine generator, the check valve, and a steam user. One end of the steam circuit control valve is connected between the outlet end of the water side of the molten salt-water heat exchanger and the power generation circuit control valve, and the other end of the steam circuit control valve is connected to the pipeline between the check valve and the steam user. The inlet end of the water side of the molten salt-water heat exchanger is connected in series with the main feed water pump and the condenser and then connected to the pipeline between the steam turbine generator and the check valve.

[0006] In a specific embodiment of the present application, the nuclear power generation and steam supply system further includes a solar thermal energy storage system. The solar thermal energy storage system is disposed outside the molten salt pipeline between the outlet end of the molten salt fluid side of the sodium-molten salt heat exchanger and the high-temperature molten salt tank. In the solar thermal energy storage mode, the sodium-cooled fast reactor is maintained at full power operation, the sodium pump and the high-temperature molten salt transfer pump operate at rated power, and the solar thermal energy storage system is used to heat the molten salt pipeline, and the low-temperature molten salt transfer pump operates at high power.

[0007] In a specific embodiment of the present application, the solar thermal energy storage system adopts a linear Fresnel concentrating system.

[0008] In a specific embodiment of the present application, the sodium-molten salt heat exchanger adopts a double-pipe design, and inert gas is used between the double pipes. The hot medium flows through the inner side of the double pipes, and the cold medium flows through the shell side of the double pipes.

[0009] In a specific embodiment of the present application, the nuclear power generation and steam supply system further includes a main transformer, a storage transformer, a super capacitor, and a nuclear-grade battery pack. The power generation outlet of the steam turbine generator is connected in series with the main transformer and the grid user in sequence. The super capacitor and the storage transformer are connected in series in sequence and are connected in parallel with the connecting pipeline between the power generation outlet of the steam turbine generator and the main transformer. The super capacitor is connected to the nuclear-grade battery pack and is used to charge and discharge the nuclear-grade battery pack regularly.

[0010] The second aspect of the present application provides a method for using a nuclear power generation and steam supply system, and the method for using the nuclear power generation and steam supply system is implemented by using a nuclear power generation and steam supply system according to the first aspect of the present application. In all modes, the sodium-cooled fast reactor operates at full power. The low-temperature molten salt transfer pump and the high-temperature molten salt transfer pump are variable-frequency pumps, and their operating conditions are set with low-power, rated-power, and high-power operating modes. The nuclear power generation and steam supply system has a power generation mode and a high-temperature industrial steam supply mode. The method for using the nuclear power generation and steam supply system includes:

[0011] When the nuclear power generation and steam supply system is in the power generation mode, the first regulating valve, the second regulating valve, and the power generation loop control valve are opened, the steam loop control valve is closed, and the low-temperature molten salt transfer pump and the high-temperature molten salt transfer pump operate at rated power. At this time, the liquid levels of the high-temperature molten salt tank and the low-temperature molten salt tank remain unchanged. The condensate is transported by the main feed water pump, undergoes heat exchange through the molten salt-water heat exchanger, then becomes saturated steam through the superheater, and finally generates electricity through the steam turbine generator. The exhaust steam of the steam turbine in the steam turbine generator can be transported to the steam user;

[0012] When the nuclear power generation steam supply system is in the high-temperature industrial steam supply mode, the first regulating valve, the second regulating valve, and the steam circuit control valve are opened, the power generation circuit control valve is closed, the low-temperature molten salt transfer pump and the high-temperature molten salt transfer pump operate at their rated power, and the liquid levels of the high-temperature molten salt tank and the low-temperature molten salt tank remain unchanged. The condensate water is transported by the main feed water pump through the molten salt-water heat exchanger for heat exchange, and the generated high-temperature industrial steam is directly transported to the steam users.

[0013] In a specific embodiment of the present application, the nuclear power generation steam supply system also has a primary frequency modulation and peak shaving mode. The method for using the nuclear power generation steam supply system further includes: when the nuclear power generation steam supply system is in the primary frequency modulation and peak shaving mode, mode one or mode two is adopted when the power is reduced. Mode three is adopted when the power is increased.

[0014] Mode one: The secondary loop sodium pump operates at full power, the low-temperature molten salt transfer pump operates at rated power, the high-temperature molten salt transfer pump operates at low power, and the main feed water pump operates at low power.

[0015] Mode two: While the power generation mode of the nuclear power generation steam supply system is turned on, the high-temperature industrial steam supply mode of the nuclear power generation steam supply system is synchronously turned on, and the amount of industrial steam supply is controlled by the opening degree of the steam circuit control valve.

[0016] Mode three: The secondary loop sodium pump operates at full power, the low-temperature molten salt transfer pump maintains rated power operation, and the high-temperature molten salt transfer pump and the main feed water pump operate at high power.

[0017] In a specific embodiment of the present application, the method for using the nuclear power generation steam supply system further includes: when the power is reduced, the power generation mode of the nuclear power generation steam supply system remains unchanged, and a super capacitor and a nuclear-grade battery pack are synchronously connected to the power generation outlet of the steam turbine generator for charging; when the power is increased, the power generation mode of the nuclear power generation steam supply system remains unchanged, and a super capacitor and a nuclear-grade battery pack are synchronously connected to the power grid connection end of the power station for discharging.

[0018] The beneficial effects of the technical solution of this application are as follows: By setting structures such as sodium - molten salt heat exchangers, low - temperature molten salt tanks, and high - temperature molten salt tanks and their connection relationships in this nuclear power generation and steam supply system, this nuclear power generation and steam supply system adopts a sodium - sodium - molten salt - water four - loop design. Compared with existing fast reactors that adopt a sodium - sodium - water three - loop design (where the possibility of sodium - water reaction has not been eliminated), this nuclear power generation and steam supply system can effectively ensure the isolation of sodium from molten salt and water, avoiding reactions such as sodium - water reactions. Additionally, by controlling the power of the low - temperature molten salt transfer pump and the high - temperature molten salt transfer pump and the opening degree of the steam circuit control valve, the steam volume supplied to the steam turbine generator is adjusted, thereby controlling the power generation of the steam turbine generator, enabling this nuclear power generation and steam supply system to have good frequency modulation and peak shaving capabilities. Furthermore, by controlling the opening and closing of the first regulating valve, the second regulating valve, the steam circuit control valve, and the power generation circuit control valve, this nuclear power generation and steam supply system can simultaneously achieve multiple functions such as sodium - cooled fast reactor power generation and manufacturing industrial high - temperature steam. Brief Description of the Drawings

[0019] Figure 1 The figure shows a schematic diagram of a nuclear power generation and steam supply system provided by an embodiment of this application.

[0020] Figure 2 The figure shows a schematic diagram of a peak - shaving response curve of a nuclear power generation and steam supply system provided by an embodiment of this application for molten salt energy storage peak - shaving.

[0021] In the figure: 1, sodium - cooled fast reactor; 2, intermediate heat exchanger; 3, secondary circuit sodium pump; 4, sodium - molten salt heat exchanger; 5, low - temperature molten salt transfer pump; 6, solar thermal energy storage system; 7, first regulating valve; 8, low - temperature molten salt tank; 9, high - temperature molten salt tank; 10, second regulating valve; 11, high - temperature molten salt transfer pump; 12, molten salt - water heat exchanger; 13, steam circuit control valve; 14, power generation circuit control valve; 15, superheater; 16, main feed water pump; 17, steam turbine generator; 18, check valve; 19, steam user; 20, condenser; 21, main transformer; 22, grid user; 23, energy storage transformer; 24, super capacitor; 25, storage battery. Detailed Embodiments

[0022] Next, the technical solutions in the embodiments of this application will be clearly and completely described in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0023] At least one embodiment of this application provides a nuclear power generation and steam supply system. Refer to Figure 1, the nuclear power generation and steam supply system includes a sodium-cooled fast reactor 1, an intermediate heat exchanger 2, a secondary sodium pump 3, a sodium-salt heat exchanger 4, a low-temperature molten salt transfer pump 5, a first regulating valve 7, a low-temperature molten salt tank 8, a high-temperature molten salt tank 9, a second regulating valve 10, a high-temperature molten salt transfer pump 11, a molten salt-water heat exchanger 12, a steam circuit control valve 13, a power generation circuit control valve 14, a superheater 15, a main feed water pump 16, a steam turbine generator 17, a check valve 18, and a condenser 20. The intermediate heat exchanger 2 is immersed in the sodium pool of the sodium-cooled fast reactor 1. The secondary sodium pump 3 is connected in series between the outlet end of the intermediate heat exchanger 2 and the inlet end of the sodium side of the sodium-salt heat exchanger 4. The inlet end of the intermediate heat exchanger 2 is connected to the outlet end of the sodium side of the sodium-salt heat exchanger 4. The outlet end of the molten salt fluid side of the sodium-salt heat exchanger 4 is connected in series with the high-temperature molten salt tank 9, the second regulating valve 10, the high-temperature molten salt transfer pump 11, and the inlet end of the molten salt fluid side of the molten salt-water heat exchanger 12. The inlet end of the molten salt fluid side of the sodium-salt heat exchanger 4 is connected in series with the low-temperature molten salt transfer pump 5, the first regulating valve 7, the low-temperature molten salt tank 8, and the outlet end of the molten salt fluid side of the molten salt-water heat exchanger 12. The outlet end of the water side of the molten salt-water heat exchanger 12 is connected in sequence with the power generation circuit control valve 14, the superheater 15, the steam turbine generator 17, the check valve 18, and a steam user 19. One end of the steam circuit control valve 13 is connected between the outlet end of the water side of the molten salt-water heat exchanger 12 and the power generation circuit control valve 14, and the other end of the steam circuit control valve 13 is connected to the pipeline between the check valve 18 and the steam user 19. The inlet end of the water side of the molten salt-water heat exchanger 12 is connected in series with the main feed water pump 16 and the condenser 20 and then connected to the pipeline between the steam turbine generator 17 and the check valve 18.

[0024] It should be noted that the intermediate heat exchanger 2, the secondary sodium pump 3, and the sodium side of the sodium-salt heat exchanger 4 together constitute the secondary circuit; the molten salt fluid side of the sodium-salt heat exchanger 4, the low-temperature molten salt transfer pump 5, the first regulating valve 7, the low-temperature molten salt tank 8, the high-temperature molten salt tank 9, the second regulating valve 10, the high-temperature molten salt transfer pump 11, and the molten salt fluid side of the molten salt-water heat exchanger 12 constitute the tertiary circuit; the water side of the molten salt-water heat exchanger 12, the steam circuit control valve 13, the power generation circuit control valve 14, the superheater 15, the main feed water pump 16, the steam turbine generator 17, the check valve 18, the steam user 19, and the condenser 20 constitute the quaternary circuit.

[0025] According to the technical solution provided by the embodiments of the present application, by designing the structures such as the sodium-molten salt heat exchanger 4, the low-temperature molten salt tank 8, and the high-temperature molten salt tank 9 in the nuclear power generation and steam supply system and their connection relationships, the nuclear power generation and steam supply system adopts a four-loop design of sodium-sodium-molten salt-water. Compared with the existing fast reactor that adopts a three-loop design of sodium-sodium-water (the possibility of sodium-water reaction has not been eliminated), the nuclear power generation and steam supply system can effectively ensure the isolation of sodium from molten salt and water, avoiding reactions such as sodium-water reaction. In addition, by controlling the power of the low-temperature molten salt transfer pump 5 and the high-temperature molten salt transfer pump 11 and the opening degree of the steam circuit control valve 13, the steam flow rate to the steam turbine generator 17 is adjusted, thereby controlling the power generation power of the steam turbine generator 17, making the nuclear power generation and steam supply system have good frequency modulation and peak shaving capabilities. In addition, by controlling the opening and closing of the first regulating valve 7, the second regulating valve 10, the steam circuit control valve 13, and the power generation circuit control valve 14, the nuclear power generation and steam supply system can simultaneously achieve multiple purposes such as sodium-cooled fast reactor power generation and manufacturing industrial high-temperature steam.

[0026] In at least one embodiment of the present application, the nuclear power generation and steam supply system further includes a solar thermal energy storage system 6. The solar thermal energy storage system 6 is arranged outside the molten salt pipeline between the outlet end of the molten salt fluid side of the sodium-molten salt heat exchanger 4 and the high-temperature molten salt tank 9. In the solar thermal energy storage mode, the sodium-cooled fast reactor 1 is maintained at full power operation, the sodium pump 3 and the high-temperature molten salt transfer pump 11 operate at rated power, the solar thermal energy storage system 6 is used to heat the molten salt pipeline, and the low-temperature molten salt transfer pump 5 operates at high power. Thus, in the solar thermal energy storage mode, the liquid level of the high-temperature molten salt tank 9 rises, and the liquid level of the low-temperature molten salt tank 8 drops. By adjusting the amounts of high-temperature and low-temperature molten salt, part of the core nuclear energy and solar energy are converted into molten salt thermal energy for storage.

[0027] It should be noted that the nuclear power generation and steam supply system can adopt a single power generation mode, high-temperature industrial steam supply mode, or solar thermal energy storage mode, or a mixture of multiple modes. The embodiments of the present application do not make specific limitations on this. The solar thermal energy storage system 6 can be simply referred to as the energy storage system.

[0028] In at least one embodiment of the present application, the solar thermal energy storage system 6 adopts a linear Fresnel concentrating system. Thus, by utilizing the advantages of high-energy concentration and thermal energy conversion of the linear Fresnel concentrating system, the energy conversion efficiency is significantly improved.

[0029] In at least one embodiment of the present application, the sodium-molten salt heat exchanger 4 adopts a double-pipe design, and inert gas is used between the double pipes. The hot medium (such as sodium) flows inside the double pipes, and the cold medium (such as molten salt) flows on the shell side of the double pipes. Thus, the heat exchange function is ensured, and the possibility of sodium-molten salt contact is further avoided. In addition, by setting the hot medium (such as sodium) to flow inside the double pipes and the cold medium (such as molten salt) to flow on the shell side of the double pipes, reactions between sodium and molten salt, water and other media can be effectively avoided, ensuring the heat exchange efficiency while improving the inherent safety of the system.

[0030] In at least one embodiment of the present application, the nuclear power generation and steam supply system further includes a main transformer 21, an energy storage transformer 23, a super capacitor 24, and a nuclear-grade battery pack 25. The power generation outlet of the steam turbine generator 17 is connected in series with the main transformer 21 and the grid user 22 in sequence. The super capacitor 24 and the energy storage transformer 23 are connected in series in sequence and are connected in parallel with the connecting pipeline between the power generation outlet of the steam turbine generator 17 and the main transformer 21. The super capacitor 24 is connected to the nuclear-grade battery pack 25 and is used to charge and discharge the nuclear-grade battery pack 25 regularly.

[0031] In the above embodiment, by using the main transformer 21, the energy storage transformer 23, the super capacitor 24, and the nuclear-grade battery pack 25 to form a molten salt energy storage loop, the switching between sodium-cooled fast reactor power generation and the production of high-temperature industrial steam is realized to achieve unit peak shaving. It can save nearly 20 million yuan of peak shaving penalty costs for the power plant every year. At the same time, by participating in peak shaving, it can enjoy peak shaving electricity prices and generate additional economic benefits. In addition, the power generation outlet of the steam turbine generator 17 is synchronously connected to the super capacitor 24 and the nuclear-grade battery pack 25 for charging. Through the flow regulation of the molten salt energy storage loop, without adjusting the reactor power, the nuclear power generation and steam supply system can realize the functions of power generation, industrial steam production, and peak shaving. The combination of the super capacitor 24 and the nuclear-grade battery pack 25 can be used for frequency modulation and peak shaving and can also be used as an in-plant emergency power supply system. Existing nuclear power units that have been put into production do not have the ability of frequency modulation and peak shaving. By adopting the nuclear power generation and steam supply system of the above embodiment of the present application, it can simultaneously realize uses such as sodium-cooled fast reactor power generation and the production of high-temperature industrial steam (for the schematic diagram of the peak shaving response curve, see Figure 2 )

[0032] At the same time, the above embodiment realizes the full combination of the super capacitor energy storage technology and the in-plant emergency power supply of the fast reactor power station, replaces related sub-items and equipment such as emergency and reliable diesel generator sets. While meeting the energy storage and realizing the secondary frequency modulation function, it greatly reduces the investment of the power plant (for example, saves more than 1 billion yuan of investment), ensures the safety and reliability of the power supply, and greatly improves the economy and safety of the fast reactor power station. At the same time, the emergency and reliable diesel sub-items and equipment of the power plant, as well as a large amount of manpower and material costs during the operation stage, can be cancelled.

[0033] At least one embodiment of the present application further provides a usage method of the nuclear power generation and steam supply system. The usage method of the nuclear power generation and steam supply system is executed by using the nuclear power generation and steam supply system in the above embodiment. In all modes, the sodium-cooled fast reactor 1 operates at full power. The low-temperature molten salt transfer pump 5 and the high-temperature molten salt transfer pump 11 are variable-frequency pumps, and their operating conditions are set with operating modes of low power, rated power, and high power. The nuclear power generation and steam supply system has a power generation mode and a high-temperature industrial steam supply mode. The usage method of the nuclear power generation and steam supply system includes the following steps.

[0034] S100: When the nuclear power generation and steam supply system is in the power generation mode, open the first regulating valve 7, the second regulating valve 10, and the power generation loop control valve 14, close the steam loop control valve 13, and operate the low-temperature molten salt transfer pump 5 and the high-temperature molten salt transfer pump 11 at their rated power. At this time, the liquid levels of the high-temperature molten salt tank 9 and the low-temperature molten salt tank 8 remain unchanged. The condensate is transported by the main feed water pump 16, undergoes heat exchange in the molten salt-water heat exchanger 12, then becomes saturated steam after passing through the superheater 15, and finally generates electricity through the steam turbine generator 17. The exhaust steam of the steam turbine in the steam turbine generator 17 is transported to the steam user 19.

[0035] S200: When the nuclear power generation and steam supply system is in the high-temperature industrial steam supply mode, open the first regulating valve 7, the second regulating valve 10, and the steam loop control valve 13, close the power generation loop control valve 14, operate the low-temperature molten salt transfer pump 5 and the high-temperature molten salt transfer pump 11 at their rated power, and the liquid levels of the high-temperature molten salt tank 9 and the low-temperature molten salt tank 8 remain unchanged. The condensate is transported by the main feed water pump 16, undergoes heat exchange in the molten salt-water heat exchanger 12, and the generated high-temperature industrial steam is directly transported to the steam user 19.

[0036] It should be noted that the low power and high power can be set according to the frequency modulation and peak shaving requirements. The low power is the pump power lower than the rated power calibrated according to the operation of the energy storage system. The rated power is the rated pump power when the energy storage system is not put into operation. The high power is the pump power higher than the rated power calibrated according to the operation of the energy storage system.

[0037] In at least one embodiment of the present application, the nuclear power generation and steam supply system also has a primary frequency modulation and peak shaving mode. The method for using the nuclear power generation and steam supply system further includes S300.

[0038] S300: When the nuclear power generation and steam supply system is in the primary frequency modulation and peak shaving mode, mode one or mode two is adopted when the power is reduced. Mode three is adopted when the power is increased.

[0039] Mode one: The secondary loop sodium pump 3 operates at full power, the low-temperature molten salt transfer pump 5 operates at rated power, the high-temperature molten salt transfer pump 11 operates at low power, and the main feed water pump 16 operates at low power.

[0040] Mode two: While starting the power generation mode of the nuclear power generation and steam supply system, synchronously start the high-temperature industrial steam supply mode of the nuclear power generation and steam supply system, and control the amount of industrial steam supply through the opening of the steam loop control valve 13.

[0041] Mode three: The secondary loop sodium pump 3 operates at full power, the low-temperature molten salt transfer pump 5 maintains rated power operation, and the high-temperature molten salt transfer pump 11 and the main feed water pump 16 operate at high power.

[0042] In the above embodiments, in Mode 1, by setting the secondary sodium pump 3 to operate at full power, the heat of the sodium-cooled fast reactor 1 can be continuously removed by the secondary sodium pump 3. By setting the high-temperature molten salt transfer pump 11 to operate at low power, the rotational speed and flow rate of the high-temperature molten salt transfer pump 11 can be reduced. By setting the main feed water pump 16 to operate at low power, the total amount of steam can be reduced, and finally the output electric power of the steam turbine generator 17 can be reduced, thereby realizing unit peak shaving. At this time, the liquid level of the high-temperature molten salt tank 9 will rise, and the liquid level of the low-temperature molten salt tank 8 will continuously decrease. By adjusting the storage amounts of the high- and low-temperature molten salts, the excess energy generated in the reactor core can be stored.

[0043] In Mode 2, by simultaneously activating the power generation mode and the high-temperature industrial steam supply mode of the nuclear power generation and steam supply system, the amount of industrial steam supply is controlled by the opening degree of the steam circuit control valve 13, thereby reducing the power generation power of the steam turbine generator 17 and realizing unit peak shaving.

[0044] In Mode 3, by setting the secondary sodium pump 3 to operate at full power, the heat of the sodium-cooled fast reactor 1 can be continuously removed by the secondary sodium pump 3. By setting the low-temperature molten salt transfer pump 5 to operate at rated power, and the high-temperature molten salt transfer pump 11 and the main feed water pump 16 to operate at high power, the rotational speed and flow rate of the high-temperature molten salt transfer pump 11 can be increased, the total amount of steam can be increased, and the output electric power of the steam turbine generator 17 can be increased, realizing unit peak shaving. At this time, the liquid level of the high-temperature molten salt tank 9 will decrease, and the liquid level of the low-temperature molten salt tank 8 will continuously rise. By adjusting the storage amounts of the high- and low-temperature molten salts, the molten salt energy storage is released, the power generation power of the steam turbine generator 17 is increased, and the grid-connected power of the power station is increased.

[0045] In at least one embodiment of the present application, the method for using the nuclear power generation and steam supply system further includes S400 and S500.

[0046] S400: When the power is reduced, keep the power generation mode of the nuclear power generation and steam supply system unchanged, and simultaneously connect a super capacitor 24 and a nuclear-grade battery pack 25 to the power generation outlet of the steam turbine generator 17 for charging.

[0047] S500: When the power is increased, keep the power generation mode of the nuclear power generation and steam supply system unchanged, and simultaneously connect a super capacitor 24 and a nuclear-grade battery pack 25 to the grid-connected end of the power station for discharging.

[0048] In this way, by executing step S400, the grid-connected power of the power station can be effectively reduced, and unit frequency modulation can be quickly realized. By executing step S500, the grid-connected power of the fast reactor power station can be increased, and secondary unit frequency modulation can be realized.

[0049] It should be noted that the combination manners of the technical features in the embodiments of the present application are not limited to the combination manners recorded in the embodiments of the present application or the combination manners recorded in the specific embodiments. All the technical features recorded in the present application can be freely combined or combined in any manner, unless contradictions occur among them.

[0050] As shown in the present application and the claims, unless the context clearly indicates an exceptional situation, words such as "a", "one kind" and / or "the" do not specifically refer to the singular, but may also include the plural. Generally speaking, the term "comprising" only indicates the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0051] The foregoing are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present application shall be included within the protection scope of the present application.

Claims

1. A nuclear power generation steam supply system, characterized in that, It includes a sodium-cooled fast reactor, an intermediate heat exchanger, a secondary sodium pump, a sodium-salt molten salt heat exchanger, a low-temperature molten salt transfer pump, a first regulating valve, a low-temperature molten salt tank, a high-temperature molten salt tank, a second regulating valve, a high-temperature molten salt transfer pump, a molten salt-water heat exchanger, a steam circuit control valve, a power generation circuit control valve, a superheater, a main feed water pump, a steam turbine generator, a check valve and a condenser. Among them, the intermediate heat exchanger is immersed in the sodium pool of the sodium-cooled fast reactor. The secondary sodium pump is connected in series between the outlet end of the intermediate heat exchanger and the inlet end of the sodium side of the sodium-salt molten salt heat exchanger. The inlet end of the intermediate heat exchanger is connected to the outlet end of the sodium side of the sodium-salt molten salt heat exchanger. The outlet end of the molten salt fluid side of the sodium-salt molten salt heat exchanger is connected in series with the high-temperature molten salt tank, the second regulating valve, the high-temperature molten salt transfer pump and the inlet end of the molten salt fluid side of the molten salt-water heat exchanger in sequence. The inlet end of the molten salt fluid side of the sodium-salt molten salt heat exchanger is connected in series with the low-temperature molten salt transfer pump, the first regulating valve, the low-temperature molten salt tank and the outlet end of the molten salt fluid side of the molten salt-water heat exchanger in sequence. The outlet end of the water side of the molten salt-water heat exchanger is connected in series with the power generation circuit control valve, the superheater, the steam turbine generator, the check valve and the steam user in sequence. One end of the steam circuit control valve is connected between the outlet end of the water side of the molten salt-water heat exchanger and the power generation circuit control valve, and the other end of the steam circuit control valve is connected to the pipeline between the check valve and the steam user. The inlet end of the water side of the molten salt-water heat exchanger is connected in series with the main feed water pump and the condenser and then connected to the pipeline between the steam turbine generator and the check valve. It further includes a solar thermal energy storage system, which is arranged on the outer side of the molten salt pipeline between the outlet end of the molten salt fluid side of the sodium-salt molten salt heat exchanger and the high-temperature molten salt tank. In the solar thermal energy storage mode, the sodium-cooled fast reactor is maintained at full power operation, the sodium pump and the high-temperature molten salt transfer pump operate at rated power, the solar thermal energy storage system is used to heat the molten salt pipeline, and the low-temperature molten salt transfer pump operates at high power.

2. The nuclear power generation steam supply system according to claim 1, characterized in that The solar thermal energy storage system adopts a linear Fresnel concentrating system.

3. A nuclear power generation steam supply system according to claim 1, characterized in that, The sodium-salt molten salt heat exchanger adopts a double-pipe design. An inert gas is used between the double pipes. The hot medium flows through the inner side of the double pipes, and the cold medium flows through the shell side of the double pipes.

4. A nuclear power generation steam supply system according to any one of claims 1 to 3, characterized in that, It further includes a main transformer, an energy storage transformer, a super capacitor and a nuclear-grade battery pack. The power generation outlet of the steam turbine generator is connected in series with the main transformer and the grid user in sequence. The super capacitor and the energy storage transformer are connected in series in sequence and are connected in parallel with the pipeline between the power generation outlet of the steam turbine generator and the main transformer. The super capacitor is connected to the nuclear-grade battery pack and is used to charge and discharge the nuclear-grade battery pack regularly.

5. A method for using a steam supply system for nuclear power generation, characterized in that, It is implemented by using a nuclear power generation and steam supply system as described in any one of claims 1 to 4. In all modes, the sodium-cooled fast reactor in the nuclear power generation and steam supply system operates at full power. The low-temperature molten salt transfer pump and the high-temperature molten salt transfer pump are variable-frequency pumps, and their operating conditions are set with low-power, rated-power and high-power operating modes. This nuclear power generation and steam supply system has a power generation mode, a high-temperature industrial steam supply mode and a solar thermal energy storage mode. Among them, the usage method of the nuclear power generation and steam supply system includes: When the nuclear power generation steam supply system is in the power generation mode, the first regulating valve, the second regulating valve and the power generation loop control valve are opened, the steam loop control valve is closed, and the low-temperature molten salt transfer pump and the high-temperature molten salt transfer pump operate at their rated powers. At this time, the liquid levels of the high-temperature molten salt tank and the low-temperature molten salt tank remain unchanged; the condensate water is transported by the main feed water pump, undergoes heat exchange through the molten salt-water heat exchanger, then becomes saturated steam through the superheater, and finally generates electricity through the steam turbine generator. The exhaust steam of the steam turbine in the steam turbine generator is transported to the steam user; When the nuclear power generation steam supply system is in the high-temperature industrial steam supply mode, the first regulating valve, the second regulating valve and the steam loop control valve are opened, the power generation loop control valve is closed, the low-temperature molten salt transfer pump and the high-temperature molten salt transfer pump operate at their rated powers, the liquid levels of the high-temperature molten salt tank and the low-temperature molten salt tank remain unchanged, the condensate water is transported by the main feed water pump, undergoes heat exchange through the molten salt-water heat exchanger, and the generated high-temperature industrial steam is directly transported to the steam user; When the nuclear power generation steam supply system is in the solar thermal energy storage mode, the sodium-cooled fast reactor is maintained at full power operation, the sodium pump and the high-temperature molten salt transfer pump operate at their rated powers, the molten salt pipeline is heated by the solar thermal energy storage system, and the low-temperature molten salt transfer pump operates at high power.

6. The usage method of a nuclear power generation steam supply system according to claim 5, characterized in that, The nuclear power generation steam supply system also has a primary frequency modulation and peak shaving mode. The usage method of the nuclear power generation steam supply system also includes: When the nuclear power generation steam supply system is in the primary frequency modulation and peak shaving mode, mode one or mode two is adopted when the power is reduced, and mode three is adopted when the power is increased. Mode one: The sodium pump in the secondary loop operates at full power, the low-temperature molten salt transfer pump operates at its rated power, the high-temperature molten salt transfer pump operates at low power, and the main feed water pump operates at low power. Mode two: While the power generation mode of the nuclear power generation steam supply system is turned on, the high-temperature industrial steam supply mode of the nuclear power generation steam supply system is synchronously turned on, and the amount of industrial steam supply is controlled by the opening degree of the steam loop control valve. Mode three: The sodium pump in the secondary loop operates at full power, the low-temperature molten salt transfer pump maintains its rated power operation, and the high-temperature molten salt transfer pump and the main feed water pump operate at high power.

7. The usage method of a nuclear power generation steam supply system according to claim 5, characterized in that, It also includes: When the power is reduced, the power generation mode of the nuclear power generation steam supply system remains unchanged, and a super capacitor and a nuclear-grade battery pack are synchronously connected to the power generation outlet of the steam turbine generator for charging; When the power is increased, the power generation mode of the nuclear power generation steam supply system remains unchanged, and a super capacitor and a nuclear-grade battery pack are synchronously connected to the power grid connection end of the power station for discharging.

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