A steam energy storage heating system for nuclear power units

Abstract

The present application provides a steam energy storage heating system for a nuclear power unit, including a saturated steam system, a steam accumulator system and a superheated steam system. The steam accumulator system is provided with a steam accumulator heating steam inlet, a steam accumulator water filling inlet, a steam accumulator heating steam outlet and a steam accumulator plant steam outlet. The saturated steam system supplies heat storage steam to the steam accumulator system through the steam accumulator heating steam inlet. The saturated steam system provides initial water filling to the steam accumulator system through the steam accumulator water filling inlet. The steam accumulator system provides saturated steam to the superheated steam system through the steam accumulator heating steam outlet. The steam accumulator system provides plant saturated steam to the plant steam main pipe through the steam accumulator plant steam outlet. The present application solves the problems of low heating efficiency and high cost of the existing nuclear power unit heating system by adding a steam accumulator system to the steam energy storage heating system of the nuclear power unit.

Description

Technical Field

[0001] The present application belongs to the field of nuclear power technology, and specifically relates to a steam energy storage heating system for a nuclear power unit. Background Art

[0002] When the nuclear power unit is supplying heat to users in the steam output state, the change in user load will cause the unit's power generation to change, and the reactor power will be adjusted frequently. There is a lack of heat storage and heat release devices that can change with user load to avoid large changes and adjustments in the nuclear power unit's power and nuclear power. When the user's heat load is large during the day, the power of the heating nuclear power unit decreases to meet the demand of the power grid load. On the contrary, at night, the power generation of the heating nuclear power unit is opposite to the power grid load demand. The change in nuclear power will increase the risk of nuclear fuel damage and increase the amount of radioactive waste in the unit.

[0003] Nuclear power units are generally equipped with oil-fired or electric starting boilers. Oil-fired boilers face environmental issues, electric boilers have high energy consumption and are expensive, and starting boilers are rarely used and are in standby mode for a long time, with high maintenance costs. Low-cost transformation or alternative solutions are urgently needed.

[0004] When nuclear power units are peaking, they generally reduce nuclear power and electric power to respond to grid dispatch, resulting in a reduction in the utilization hours of nuclear power units. Adjustment of nuclear power causes an increase in radioactive waste and increases the risk of nuclear fuel damage. There is a lack of corresponding energy storage measures and methods to achieve peaking of nuclear power units by only changing the secondary circuit electric power to respond to the peaking needs of the grid.

[0005] For example, the patent CN 110631112 A "A Steam Energy Storage Peak Shaving System and Method for Heating Units" proposes a method of using a steam accumulator to store the heat of the unit's steam extraction and supply heat to users and heat exchangers in the plant. The steam generated by the steam extraction heating unit enters the steam accumulator, heats the feed water in the steam accumulator and mixes with the feed water. The steam in the steam accumulator is adjusted to the parameters required by the user by the temperature and pressure regulating device and then supplied to the user. However, there is a potential radioactive risk in the secondary circuit of the nuclear power unit, and the steam in the secondary circuit should not be directly supplied to users. This patent does not meet the safety requirements of steam energy storage heating for nuclear power units. Summary of the invention

[0006] In view of this, the present application is committed to providing a nuclear power unit steam energy storage heating system, by adding a steam accumulator system to the nuclear power unit steam energy storage heating system, to solve the problems of low heating efficiency and high cost of the existing nuclear power unit heating system.

[0007] The present application provides a steam energy storage heating system for a nuclear power unit, which includes a saturated steam system, a steam accumulator system and a superheated steam system. The steam accumulator system is provided with a steam accumulator heating steam inlet, a steam accumulator water filling inlet, a steam accumulator heating steam outlet and a steam accumulator plant steam outlet. The saturated steam system supplies heat storage steam to the steam accumulator system through the steam accumulator heating steam inlet. The saturated steam system provides initial water filling to the steam accumulator system through the steam accumulator water filling inlet. The steam accumulator system provides saturated steam to the superheated steam system through the steam accumulator heating steam outlet. The steam accumulator system provides plant saturated steam to the plant steam main pipe through the steam accumulator plant steam outlet.

[0008] In a specific embodiment of the present application, the saturated steam system includes an evaporator and a feedwater preheater. The superheated steam system includes a steam superheater, a bypass steam superheater heating steam pipeline and an electric superheater. The steam superheater is used to heat saturated steam into superheated steam using main steam or turbine extraction steam and supply it to users. The electric superheater is used to supply superheated steam to users when the main steam or turbine extraction steam of the nuclear power unit is unavailable. The steam superheater is provided with a steam superheater heating steam inlet, a steam superheater heating steam outlet, a steam superheater saturated steam inlet and a steam superheater superheated steam outlet. The electric superheater is connected in series to the corresponding pipeline of the steam superheater superheater superheated steam outlet of the steam superheater. One end of the bypass steam superheater heating steam pipeline is connected to the corresponding pipeline of the steam superheater heating steam inlet, and the other end of the bypass steam superheater heating steam pipeline is connected to the corresponding pipeline of the steam superheater heating steam outlet. The steam superheater heating steam outlet is connected to the evaporator. In the saturated steam system, the evaporator supplies the stored steam to the steam accumulator system through the steam accumulator heating steam inlet. In the saturated steam system, the feedwater preheater provides the steam accumulator system with initial water filling through the steam accumulator water filling inlet. The steam accumulator system provides saturated steam to the steam superheater through a pipeline connecting the steam accumulator heating steam outlet and the steam superheater saturated steam inlet.

[0009] In a specific embodiment of the present application, the evaporator is provided with an evaporator heating steam inlet, an evaporator heating steam outlet, an evaporator water inlet and an evaporator saturated steam outlet. The feedwater preheater is provided with a feedwater preheater heating water inlet, a feedwater preheater water outlet and a steam accumulator water filling outlet. The steam superheater heating steam outlet is connected to the evaporator heating steam inlet. The evaporator heating steam outlet is connected to the feedwater preheater heating water inlet. The evaporator saturated steam outlet is connected to the steam accumulator heating steam inlet. The feedwater preheater water outlet is connected to the evaporator water inlet. The steam accumulator water filling outlet is connected to the steam accumulator water filling inlet.

[0010] In a specific embodiment of the present application, the evaporator is provided with an evaporator heating steam inlet, an evaporator heating steam outlet, an evaporator water inlet and an evaporator saturated steam outlet. The feedwater preheater is provided with a feedwater preheater heating water inlet and a feedwater preheater water outlet. The steam superheater heating steam outlet is connected to the evaporator heating steam inlet. The evaporator heating steam outlet is connected to the feedwater preheater heating water inlet. The evaporator saturated steam outlet is connected to the steam accumulator heating steam inlet. One of the pipelines corresponding to the feedwater preheater water outlet is connected to the evaporator water inlet, and the other pipeline corresponding to the feedwater preheater water outlet is connected to the steam accumulator water filling inlet.

[0011] In a specific embodiment of the present application, the saturated steam system includes an evaporator and a feedwater preheater. The superheated steam system includes a steam superheater, a bypass steam superheater heating steam pipeline and an electric superheater. The steam superheater is used to heat saturated steam into superheated steam using main steam or turbine extraction steam and supply it to users. The electric superheater is used to supply superheated steam to users when the main steam or turbine extraction steam of the nuclear power unit is unavailable. The steam superheater is provided with a steam superheater heating steam inlet, a steam superheater heating steam outlet, a steam superheater saturated steam inlet and a steam superheater superheated steam outlet. The electric superheater is provided with an electric superheater inlet and an electric superheater outlet. In the saturated steam system, the evaporator supplies thermal storage steam to the steam accumulator system through the steam accumulator heating steam inlet. In the saturated steam system, the feedwater preheater provides initial water filling to the steam accumulator system through the steam accumulator water filling inlet. One of the pipes corresponding to the steam accumulator heating steam outlet is connected to the pipe connecting the steam superheater saturated steam inlet and the evaporator and is close to the steam superheater saturated steam inlet. Another pipe corresponding to the steam accumulator heating steam outlet is connected to the electric superheater inlet. The electric superheater outlet is connected to the pipe corresponding to the steam superheater superheated steam outlet.

[0012] In a specific embodiment of the present application, the evaporator is provided with an evaporator heating steam inlet, an evaporator heating steam outlet, an evaporator water inlet and an evaporator saturated steam outlet. The feedwater preheater is provided with a feedwater preheater heating water inlet, a feedwater preheater water outlet and a steam accumulator water filling outlet. One of the pipelines corresponding to the evaporator saturated steam outlet is connected to the steam accumulator heating steam inlet. Another pipeline corresponding to the evaporator saturated steam outlet is connected to the steam superheater saturated steam inlet. The steam accumulator water filling outlet is connected to the steam accumulator water filling inlet. The evaporator heating steam outlet is connected to the feedwater preheater heating water inlet. One end of the bypass steam superheater heating steam pipeline is connected to the pipeline corresponding to the steam superheater heating steam inlet, and the other end of the bypass steam superheater heating steam pipeline is connected to the pipeline corresponding to the steam superheater heating steam outlet and then connected to the evaporator heating steam inlet.

[0013] In a specific embodiment of the present application, the steam energy storage heating system of the nuclear power unit also includes a booster pump and a heat storage evaporator. The evaporator is provided with an evaporator heating steam inlet, an evaporator heating steam outlet, an evaporator water inlet and an evaporator saturated steam outlet. The feedwater preheater is provided with a feedwater preheater heating water inlet and a feedwater preheater water outlet. The heat storage evaporator is provided with a heat storage evaporator heating steam inlet, a heat storage evaporator heating steam outlet, a heat storage heater feedwater inlet and a heat storage heater steam outlet. One of the pipelines corresponding to the feedwater preheater water outlet is connected to the evaporator water inlet. Another pipeline corresponding to the feedwater preheater water outlet is connected to the booster pump. One of the pipelines corresponding to the outlet of the booster pump is connected to the heat storage heater feedwater inlet. Another pipeline corresponding to the outlet of the booster pump is connected to the steam accumulator water filling inlet. The heat storage evaporator heating steam inlet is connected to the evaporator heating steam inlet. The corresponding pipeline of the evaporator heating steam outlet is connected with the corresponding pipeline of the heat storage evaporator heating steam outlet and then connected with the heating water inlet of the feed water preheater. The steam outlet of the heat storage heater is connected with the heating steam inlet of the steam accumulator.

[0014] In a specific embodiment of the present application, the saturated steam system also includes a feedwater heating and deoxygenating device. The feedwater preheater is provided with a feedwater preheater heating water outlet and a feedwater preheater water inlet. The feedwater heating and deoxygenating device is provided with a feedwater heating and deoxygenating device heating water inlet and a feedwater heating and deoxygenating device water outlet. The feedwater preheater provides a heating heat source to the feedwater heating and deoxygenating device via a pipeline connecting the feedwater preheater heating water outlet and the feedwater heating and deoxygenating device heating water inlet. The feedwater heating and deoxygenating device supplies preheated deoxygenated feed water to the feedwater preheater via a pipeline connecting the feedwater heating and deoxygenating device water outlet and the feedwater preheater water inlet.

[0015] In a specific embodiment of the present application, the steam accumulator system includes at least one steam accumulator.

[0016] In a specific embodiment of the present application, at least one steam accumulator is a plurality of steam accumulators, some of which are in a high-pressure heat storage end state and some of which are in a low-pressure heat release end state to meet peak load regulation.

[0017] The beneficial effects of the technical solution of the present application are: by adding a steam heat accumulator system to the steam energy storage heating system of the nuclear power unit, the working efficiency, reliability and safety of the heating system of the nuclear power unit are improved, and the low-cost transformation and replacement method of the plant steam of the nuclear power unit is used to reduce the peak-shaving losses of the nuclear power unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Shown is a schematic structural diagram of a steam energy storage heating system for a nuclear power unit provided in one embodiment of the present application.

[0019] Figure 2 Shown is a schematic structural diagram of a steam energy storage heating system for a nuclear power unit provided in another embodiment of the present application.

[0020] Figure 3 Shown is a structural schematic diagram of a steam energy storage heating system for a nuclear power unit provided in yet another embodiment of the present application.

[0021] In the figure, 10: steam superheater; 11: steam superheater heating steam inlet; 12: steam superheater heating steam outlet; 13: steam superheater saturated steam inlet; 14: steam superheater superheated steam outlet; 15: bypass steam superheater heating steam pipeline;

[0022] 20: evaporator; 21: evaporator heating steam inlet; 22: evaporator heating steam outlet; 23: evaporator water inlet; 24: evaporator saturated steam outlet;

[0023] 30: feedwater preheater; 31: feedwater preheater heating water inlet; 32: feedwater preheater heating water outlet; 33: feedwater preheater water inlet; 34: feedwater preheater water outlet; 35: feedwater preheater water filling outlet to steam accumulator;

[0024] 40: water supply heating and deaeration device; 41: heating water inlet of water supply heating and deaeration device; 42: water outlet of water supply heating and deaeration device;

[0025] 50: thermal storage evaporator; 51: thermal storage evaporator heating steam inlet; 52: thermal storage evaporator heating steam outlet; 53: thermal storage heater feed water inlet; 54: thermal storage heater steam outlet;

[0026] 60: steam accumulator; 61: steam accumulator heating steam inlet; 62: steam accumulator water filling inlet; 63: steam accumulator heating steam outlet; 64: steam accumulator plant steam outlet;

[0027] 70: electric superheater; 71: electric superheater inlet; 72: electric superheater outlet;

[0028] 100: Booster pump. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] At least one embodiment of the present application provides a nuclear power unit steam energy storage heating system, referring to Figures 1 to 3 The steam energy storage heating system of the nuclear power unit includes a saturated steam system, a steam accumulator system and a superheated steam system. The steam accumulator system is provided with a steam accumulator heating steam inlet 61, a steam accumulator water filling inlet 62, a steam accumulator heating steam outlet 63 and a steam accumulator plant steam outlet 64. The saturated steam system supplies heat storage steam to the steam accumulator system through the steam accumulator heating steam inlet 61. The saturated steam system provides initial water filling to the steam accumulator system through the steam accumulator water filling inlet 62. The steam accumulator system provides saturated steam to the superheated steam system through the steam accumulator heating steam outlet 63. The steam accumulator system provides plant saturated steam to the plant steam main pipe through the steam accumulator plant steam outlet 64.

[0031] According to the technical solution provided in the embodiment of the present application, by adding a steam accumulator system between the saturated steam system and the superheated steam system, when the amount of heat required by the user changes, the steam accumulator system itself can be relied on to store heat and respond quickly to avoid changes in nuclear power and electric power. When the nuclear power unit is shut down, the steam accumulator system can continue to provide heat for a period of time, thereby improving the reliability of heat supply. In addition, by using steam accumulators to provide plant steam for nuclear power units, the cost of transformation and replacement of plant steam for nuclear power units is reduced, and using steam accumulators to bear the peak load of nuclear power units reduces the peak loss of nuclear power units. In the embodiment of the present application, no electric heat storage device is used, which avoids the loss of high-grade electrical energy converted into thermal energy and improves energy utilization efficiency.

[0032] In at least one embodiment of the present application, the steam accumulator system includes at least one steam accumulator 60 .

[0033] For example, Figure 1 The steam accumulator 60 shown in the figure includes one or more steam accumulators, a steam accumulator heating steam outlet 63 and a subsequent pipeline and a pressure reducing valve, a steam accumulator plant steam outlet 64 and a subsequent pipeline and a pressure reducing valve, a steam accumulator water filling inlet 62 and a steam accumulator heating steam inlet 61, a steam accumulator heating steam outlet 63 and a subsequent pipeline and a pressure reducing valve for providing saturated steam to the steam superheater 10, and a steam accumulator plant steam outlet 64 and a subsequent pipeline and a pressure reducing valve for providing plant saturated steam to the plant steam main pipe.

[0034] In at least one embodiment of the present application, reference Figures 1 to 3 , at least one steam accumulator 60 is a plurality of steam accumulators 60. Some of the steam accumulators 60 are in a high-pressure heat storage end state, and some of the steam accumulators are in a low-pressure heat release end state to meet peak load regulation.

[0035] It should be noted that in order to meet peak load regulation, smooth out user load fluctuations and provide sufficient spare plant steam, some steam accumulators can be planned to be in a high-pressure heat storage end state and some steam accumulators can be planned to be in a low-pressure heat release end state.

[0036] The steam accumulator system can be arranged in series (refer to Figure 1 ), or they can be arranged in parallel (reference Figure 2 and Figure 3 ), and this embodiment of the present application does not make any specific limitation on this.

[0037] Next, combine Figure 1 , a steam energy storage heating system for a nuclear power unit based on a series arrangement of steam accumulator systems is illustrated by way of example, and a steam accumulator system including a steam accumulator 60 is illustrated by way of example.

[0038] In at least one embodiment of the present application, reference Figure 1 The saturated steam system includes an evaporator 20 and a feedwater preheater 30. The superheated steam system includes a steam superheater 10, a bypass steam superheater heating steam pipeline 15 and an electric superheater 70. The steam superheater 10 is used to heat saturated steam into superheated steam using main steam or steam turbine extraction steam and supply it to users. The electric superheater 70 is used to supply superheated steam to users when the main steam or steam turbine extraction steam of the nuclear power unit is unavailable.

[0039] The steam superheater 10 is provided with a steam superheater heating steam inlet 11, a steam superheater heating steam outlet 12, a steam superheater saturated steam inlet 13 and a steam superheater superheated steam outlet 14. The electric superheater 70 is connected in series to the corresponding pipe of the steam superheater superheated steam outlet 14 of the steam superheater 10. One end of the bypass steam superheater heating steam pipe 15 is connected to the corresponding pipe of the steam superheater heating steam inlet 11, and the other end of the bypass steam superheater heating steam pipe 15 is connected to the corresponding pipe of the steam superheater heating steam outlet 12. The steam superheater heating steam outlet 12 is connected to the evaporator 20. In the saturated steam system, the evaporator 20 supplies thermal storage steam to the steam accumulator system through the steam accumulator heating steam inlet 61. In the saturated steam system, the feedwater preheater 30 provides initial water filling to the steam accumulator system through the steam accumulator water filling inlet 62. The steam accumulator system provides saturated steam to the steam superheater 10 through a pipeline connecting the steam accumulator heating steam outlet 63 and the steam superheater saturated steam inlet 13 .

[0040] It should be noted that the electric superheater 70 is provided with an electric superheater inlet 71 and an electric superheater outlet 72. The electric superheater inlet 71 is connected to the steam superheater superheated steam outlet 14 to realize the series connection between the electric superheater 70 and the steam superheater 10.

[0041] In at least one embodiment of the present application, the evaporator 20 is provided with an evaporator heating steam inlet 21, an evaporator heating steam outlet 22, an evaporator water inlet 23 and an evaporator saturated steam outlet 24. The feedwater preheater 30 is provided with a feedwater preheater heating water inlet 31 and a feedwater preheater water outlet 34. The steam superheater heating steam outlet 12 is connected to the evaporator heating steam inlet 21. The evaporator heating steam outlet 22 is connected to the feedwater preheater heating water inlet 31. The evaporator saturated steam outlet 24 is connected to the steam accumulator heating steam inlet 61. One way of the pipeline corresponding to the feedwater preheater water outlet 34 is connected to the evaporator water inlet 23, and the other way of the pipeline corresponding to the feedwater preheater water outlet 34 is connected to the steam accumulator water filling inlet 62.

[0042] In at least one embodiment of the present application, the evaporator 20 is provided with an evaporator heating steam inlet 21, an evaporator heating steam outlet 22, an evaporator water inlet 23 and an evaporator saturated steam outlet 24. The feedwater preheater 30 is provided with a feedwater preheater heating water inlet 31, a feedwater preheater water outlet 34 and a steam accumulator water filling outlet 35. The steam superheater heating steam outlet 12 is connected to the evaporator heating steam inlet 21. The evaporator heating steam outlet 22 is connected to the feedwater preheater heating water inlet 31. The evaporator saturated steam outlet 24 is connected to the steam accumulator heating steam inlet 61. The feedwater preheater water outlet 34 is connected to the evaporator water inlet 23. The steam accumulator water filling outlet 35 is connected to the steam accumulator water filling inlet 62.

[0043] In the above embodiment, the saturated steam generated by the evaporator 20 in the saturated steam system is supplied to the steam accumulator system for heat storage via the saturated steam outlet 24 and the steam accumulator heating steam inlet 61. The feedwater preheater 30 in the saturated steam system provides initial water filling to the steam accumulator system via the steam accumulator filling water outlet 35 and the steam accumulator filling water inlet 62. The steam accumulator system provides saturated steam to the steam superheater 10 via the steam accumulator heating steam outlet 63 and the steam superheater saturated steam inlet 13.

[0044] In at least one embodiment of the present application, reference Figures 1 to 3 The saturated steam system further includes a feedwater heating and deoxygenating device 40. The feedwater preheater 30 is provided with a feedwater preheater heating water outlet 32 ​​and a feedwater preheater water inlet 33. The feedwater heating and deoxygenating device 40 is provided with a feedwater heating and deoxygenating device heating water inlet 41 and a feedwater heating and deoxygenating device water outlet 42. The feedwater preheater 30 provides a heating heat source to the feedwater heating and deoxygenating device 40 via a pipeline connecting the feedwater preheater heating water outlet 32 ​​and the feedwater heating and deoxygenating device heating water inlet 41. The feedwater heating and deoxygenating device 40 supplies preheated and deoxygenated feed water to the feedwater preheater 30 via a pipeline connecting the feedwater heating and deoxygenating device water outlet 42 and the feedwater preheater water inlet 33.

[0045] In the above embodiment, the feed water heating and deoxygenation device 40 supplies preheated deoxygenated feed water to the feed water preheater 30, and the feed water heated by the feed water preheater 30 is supplied to the evaporator 20. The saturated steam generated by the evaporator 20 is supplied to the steam accumulator 60 for heat storage. The heating steam outlet 12 from the steam superheater is connected to the heating steam inlet 21 of the evaporator to supply heating steam to the evaporator 20, and the heating steam condensate is supplied to the heating water inlet 31 of the feed water preheater through the heating steam outlet 22 of the evaporator.

[0046] Figure 1 The working process of the steam energy storage heating system of the nuclear power unit shown includes the following steps.

[0047] The first step is to start the feed water heating deaerator 40 and the feed water preheater 30, and provide initial water filling to the steam accumulator filling inlet 62 of the steam accumulator 60 through the steam accumulator filling outlet 35 of the feed water preheater 30, and at the same time provide a heating heat source for the initial water filling by heating the steam pipe 15 through the bypass steam superheater;

[0048] In the second step, when the steam accumulator 60 is filled with water to the rated liquid level, the evaporator 20 provides the steam accumulator 60 with heat storage steam, and stores heat to the rated pressure;

[0049] The third step is to supply saturated steam to the steam superheater 10 through the steam accumulator heating steam outlet 63 and the subsequent pipeline and the pressure reducing valve, and at the same time close the valve on the bypass steam superheater heating steam pipeline 15, and input the heating steam from the steam superheater heating steam inlet 11 to supply superheated steam to the user. At this time, the steam accumulator works in the simultaneous charging and discharging operation state;

[0050] When the user load decreases, the opening of the pressure reducing valve behind the steam accumulator heating steam outlet 63 is reduced to store the excess heat of the nuclear power unit main steam or steam turbine extraction in the steam accumulator. When the user load increases, the opening of the pressure reducing valve behind the steam accumulator heating steam outlet 63 is increased to release the heat of the hot water stored in the steam accumulator 60 and increase the steam supply. The fluctuation of the user load is regulated through the heat storage and heat release process of the steam accumulator 60.

[0051] When the nuclear power unit needs to be supplied with plant steam, the pressure reducing valve after the plant steam outlet 64 of the steam accumulator is opened to provide plant saturated steam to the plant steam main pipe;

[0052] In order to ensure reliable heating supply to users and avoid unexpected supply interruption, when the nuclear power unit fails and stops operating, the pressure reducing valve after opening the steam outlet 63 of the steam accumulator to supply saturated steam to the electric superheater 70, and the power used by the unit is used to provide power to the electric superheater 70, so as to heat the saturated steam supplied by the steam accumulator 70 and supply superheated steam to users;

[0053] For example, the steam accumulator 60 includes more than one steam accumulator. When the nuclear power unit responds to peak load regulation and needs to reduce the power generation of the nuclear power unit, the valve on the bypass steam superheater heating steam pipeline 15 is opened, and the main steam of the nuclear power unit or the extraction steam of the unit heats the evaporator 20, and the saturated steam generated by the evaporator 20 is introduced into the steam accumulator 60 in a low-pressure state for storage. When the peak load of the nuclear power unit is reduced, the nuclear power remains unchanged. When the nuclear power unit responds to peak load regulation and needs to increase the power generation of the nuclear power unit, the pressure reducing valve after the steam accumulator heating steam outlet 63 in a high-pressure state is opened, and the heat storage in the steam accumulator 60 is used to provide heating saturated steam, thereby reducing the main steam or steam extraction steam consumption of the nuclear power unit, realizing rapid load increase, and ensuring the response of the nuclear power unit to the rapid load increase of the power grid.

[0054] Next, combine Figure 2 and Figure 3 , an example is given of a nuclear power unit steam energy storage heating system based on a steam heat accumulator system connected in parallel at the inlet and outlet of the evaporator.

[0055] In at least one embodiment of the present application, the saturated steam system includes an evaporator 20 and a feedwater preheater 30, and the superheated steam system includes a steam superheater 10, a bypass steam superheater heating steam pipeline 15, and an electric superheater 70. The steam superheater 10 is used to heat saturated steam into superheated steam using main steam or steam turbine extraction steam and supply it to users. The electric superheater 70 is used to supply superheated steam to users when the main steam or steam turbine extraction steam of the nuclear power unit is unavailable.

[0056] The steam superheater 10 is provided with a steam superheater heating steam inlet 11, a steam superheater heating steam outlet 12, a steam superheater saturated steam inlet 13 and a steam superheater superheated steam outlet 14. The electric superheater 70 is provided with an electric superheater inlet 71 and an electric superheater outlet 72.

[0057] One of the pipes corresponding to the steam accumulator heating steam outlet 63 is connected to the pipes connected between the steam superheater saturated steam inlet 13 and the evaporator 20 and is close to the steam superheater saturated steam inlet 13. Another pipe corresponding to the steam accumulator heating steam outlet 63 is connected to the electric superheater inlet 71. The electric superheater outlet 72 is connected to the pipe corresponding to the steam superheater superheated steam outlet 14.

[0058] In at least one embodiment of the present application, reference Figure 3 The evaporator 20 is provided with an evaporator heating steam inlet 21, an evaporator heating steam outlet 22, an evaporator water inlet 23 and an evaporator saturated steam outlet 24. The feedwater preheater 30 is provided with a feedwater preheater heating water inlet 31, a feedwater preheater water outlet 34 and a steam accumulator water filling outlet 35.

[0059] One of the pipes corresponding to the evaporator saturated steam outlet 24 is connected to the steam accumulator heating steam inlet 61. Another pipe corresponding to the evaporator saturated steam outlet 24 is connected to the steam superheater saturated steam inlet 13. The steam accumulator water filling outlet 35 is connected to the steam accumulator water filling inlet 62. The evaporator heating steam outlet 22 is connected to the feed water preheater heating water inlet 31. One end of the bypass steam superheater heating steam pipe 15 is connected to the pipe corresponding to the steam superheater heating steam inlet 11, and the other end of the bypass steam superheater heating steam pipe 15 is connected to the pipe corresponding to the steam superheater heating steam outlet 12 and then connected to the evaporator heating steam inlet 21.

[0060] In at least one embodiment of the present application, reference Figure 2 and Figure 3 The saturated steam system further includes a feedwater heating and deoxygenating device 40. The feedwater preheater 30 is provided with a feedwater preheater heating water outlet 32 ​​and a feedwater preheater water inlet 33. The feedwater heating and deoxygenating device 40 is provided with a feedwater heating and deoxygenating device heating water inlet 41 and a feedwater heating and deoxygenating device water outlet 42. The feedwater preheater heating water outlet 32 ​​is connected to the feedwater heating and deoxygenating device heating water inlet 41. The feedwater preheater 30 provides a heating heat source to the feedwater heating and deoxygenating device 40 via the feedwater preheater heating water outlet 32 ​​and the feedwater heating and deoxygenating device heating water inlet 41. The feedwater preheater water inlet 33 is connected to the feedwater heating and deoxygenating device water outlet 42. The feedwater heating and deoxygenating device 40 supplies preheated and deoxygenated feedwater to the feedwater preheater 30 via the feedwater heating and deoxygenating device water outlet 42 and the feedwater preheater water inlet 33.

[0061] The feed water heating and deoxygenation device 40 supplies preheated deoxygenated feed water to the feed water preheater 30. The feed water heated by the feed water preheater 30 is supplied to the evaporator 20. The saturated steam generated by the evaporator 20 is supplied to the steam superheater 10. The heating steam outlet 12 from the steam superheater is connected to the evaporator heating steam inlet 21 to supply heating steam to the evaporator 20. The heating steam condensate is supplied to the feed water preheater heating water inlet 31 through the evaporator heating steam outlet 22. The feed water preheater heating water outlet 32 ​​is connected to the feed water heating and deoxygenation device heating water inlet 41 to provide a heating heat source to the feed water heating and deoxygenation device 40.

[0062] In at least one embodiment of the present application, reference Figure 2The steam energy storage heating system of the nuclear power unit also includes a booster pump 100 and a thermal storage evaporator 50. The evaporator 20 is provided with an evaporator heating steam inlet 21, an evaporator heating steam outlet 22, an evaporator water inlet 23 and an evaporator saturated steam outlet 24. The feedwater preheater 30 is provided with a feedwater preheater heating water inlet 31 and a feedwater preheater water outlet 34. The thermal storage evaporator 50 is provided with a thermal storage evaporator heating steam inlet 51, a thermal storage evaporator heating steam outlet 52, a thermal storage heater feedwater inlet 53 and a thermal storage heater steam outlet 54.

[0063] One of the pipes corresponding to the feedwater preheater water outlet 34 is connected to the evaporator water inlet 23. Another pipe corresponding to the feedwater preheater water outlet 34 is connected to the booster pump 100. One of the pipes corresponding to the outlet of the booster pump 100 is connected to the thermal storage heater feedwater inlet 53. Another pipe corresponding to the outlet of the booster pump 100 is connected to the steam accumulator water filling inlet 62. The thermal storage evaporator heating steam inlet 51 is connected to the evaporator heating steam inlet 21, and is connected to the pipe after the other end of the bypass steam superheater heating steam pipe 15 merges with the corresponding pipe of the steam superheater heating steam outlet 12. The corresponding pipe of the evaporator heating steam outlet 22 merges with the corresponding pipe of the thermal storage evaporator heating steam outlet 52 and is connected to the feedwater preheater heating water inlet 31. The thermal storage heater steam outlet 54 is connected to the steam accumulator heating steam inlet 61.

[0064] It should be noted that the other end of the bypass steam superheater heating steam pipe 15 first merges with the corresponding pipe of the steam superheater heating steam outlet 12, and then is divided into two paths after the merger, one path is connected to the evaporator heating steam inlet 21, and the other path is connected to the heat storage evaporator heating steam inlet 51.

[0065] like Figure 2 As shown, the reason for setting the booster pump 100 and the heat storage evaporator 50 is that the pressure of the evaporator 20 and the steam superheater 10 of the original nuclear power unit heating system is consistent, which may not meet the use conditions of the steam heat storage 60. If the pressure of the evaporator 20 is higher than the pressure of the steam superheater 10 by more than 0.3MPa, the booster pump 100 and the heat storage evaporator 50 can be cancelled. Figure 3 As shown, the evaporator saturated steam outlet 24 supplies thermal storage steam to the steam accumulator heating steam inlet 61 , and the feedwater preheater water outlet 34 supplies water to the steam accumulator water filling inlet 62 .

[0066] The steam accumulator system comprises a steam accumulator 60, Figure 2The steam accumulator 60 shown in the figure includes more than one steam accumulator, a steam accumulator heating steam outlet 63 and its subsequent pipeline and pressure reducing valve, a steam accumulator plant steam outlet 64 and its subsequent pipeline and pressure reducing valve, a steam accumulator water filling inlet 62, a steam accumulator heating steam inlet 61, a booster pump 100 and a heat storage evaporator 50, a steam accumulator heating steam outlet 63 and its subsequent pipeline and pressure reducing valve are used to provide saturated steam to the steam superheater 10 and the electric superheater 70, and the steam accumulator plant steam outlet 64 and its subsequent pipeline and pressure reducing valve are used to The plant steam main pipe is provided with saturated steam for plant use. The inlet of the booster pump 100 is connected with the water outlet 34 of the feedwater preheater, and the waste heat feedwater is pressurized and transported to the water inlet 53 of the thermal storage evaporator. The steam outlet 54 of the thermal storage heater transports saturated steam to the thermal accumulator 60 for heat storage. The heating steam inlet 51 of the thermal storage evaporator is connected with the heating steam outlet 12 of the steam superheater and the heating steam pipeline 15 of the bypass steam superheater to provide heating steam for the thermal storage evaporator 50. The hot water at the heating steam outlet 52 of the thermal storage evaporator is transported to the heating water inlet 31 of the feedwater preheater.

[0067] Figure 2 The working process of the steam energy storage heating system of the nuclear power unit shown includes the following steps.

[0068] The first step is to start the feed water heating and deaerator 40 to supply water to the feed water preheater 30. The feed water is passed through the evaporator 20 to generate saturated steam. The saturated steam is heated by the steam superheater 10 to become superheated steam to supply heat to the user. The main steam from the nuclear power unit or the steam turbine extraction steam heats the steam superheater 10, the evaporator 20 and the feed water preheater 30 in turn, and then is sent to the feed water heating and deaerator 40.

[0069] The second step is to start the booster pump 100 to fill the steam accumulator 60 with water through the steam accumulator water filling inlet 62. When the steam accumulator 60 is filled with water to the rated liquid level, the heat storage steam is provided to the steam accumulator 60 through the heat storage evaporator 50, and the heat is stored to the rated pressure.

[0070] The third step is to provide saturated steam to the steam superheater 10 through the steam accumulator heating steam outlet 63 and the subsequent pipeline and pressure reducing valve. At this time, the steam accumulator works in the heat release operation state;

[0071] When the user load decreases, the opening of the pressure reducing valve behind the steam accumulator heating steam outlet 63 is reduced to store the excess heat of the nuclear power unit main steam or steam turbine extraction in the steam accumulator. When the user load increases, the opening of the pressure reducing valve behind the steam accumulator heating steam outlet 63 is increased to release the heat of the hot water stored in the steam accumulator 60 and increase the steam supply. The fluctuation of the user load is regulated through the heat storage and heat release process of the steam accumulator 60.

[0072] When the nuclear power unit needs to be supplied with plant steam, the pressure reducing valve after the plant steam outlet 64 of the steam accumulator is opened to provide plant saturated steam to the plant steam main pipe;

[0073] In order to ensure reliable heating supply to users and avoid unexpected supply interruption, when the nuclear power unit fails and stops operating, the pressure reducing valve after opening the steam outlet 63 of the steam accumulator to supply saturated steam to the electric superheater 70, and the power used by the unit is used to provide power to the electric superheater 70, so as to heat the saturated steam supplied by the steam accumulator 70 and supply superheated steam to users;

[0074] For example, the steam accumulator 60 includes more than one steam accumulator. When the nuclear power unit responds to peak load regulation and needs to reduce the power generation of the nuclear power unit, the valve on the bypass steam superheater heating steam pipeline 15 is opened, and the main steam of the nuclear power unit or the extraction steam of the unit heats the heat storage evaporator 50, and the saturated steam generated by the heat storage evaporator 50 is introduced into the steam accumulator 60 in a low-pressure state for storage. When the peak load of the nuclear power unit is reduced, the nuclear power remains unchanged. When the nuclear power unit responds to peak load regulation and needs to increase the power generation of the nuclear power unit, the pressure reducing valve after the steam accumulator heating steam outlet 63 in a high-pressure state is opened, and the heat storage in the steam accumulator 60 is used to provide heating saturated steam, thereby reducing the main steam or steam extraction steam consumption of the nuclear power unit and achieving rapid load increase.

[0075] It should be noted that the combination of the various technical features in the embodiments of the present application is not limited to the combination described in the embodiments of the present application or the combination described in the specific embodiments, and all technical features described in the present application can be freely combined or combined in any way unless there is a contradiction between them.

[0076] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the term "comprising" only indicates that the steps and elements that have been clearly identified are included, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0077] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0078] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A steam energy storage heating system for a nuclear power unit, characterized in that: Including saturated steam system, steam accumulator system and superheated steam system, The steam accumulator system is provided with a steam accumulator heating steam inlet, a steam accumulator water filling inlet, a steam accumulator heating steam outlet and a steam accumulator plant steam outlet. The saturated steam system supplies heat storage steam to the steam accumulator system through the steam accumulator heating steam inlet. The saturated steam system provides initial water filling to the steam accumulator system through the steam accumulator water filling inlet. The steam accumulator system provides saturated steam to the superheated steam system through the steam accumulator heating steam outlet. The steam accumulator system provides plant saturated steam to the plant steam main pipe through the steam accumulator plant steam outlet.

2. A nuclear power unit steam energy storage heating system according to claim 1, characterized in that: The saturated steam system includes an evaporator and a feedwater preheater. The superheated steam system includes a steam superheater, a bypass steam superheater heating steam pipeline and an electric superheater. The steam superheater is used to use the main steam or steam turbine extraction steam to heat the saturated steam into superheated steam and supply it to the user. The electric superheater is used to supply superheated steam to the user when the main steam or steam turbine extraction steam of the nuclear power unit is unavailable. The steam superheater is provided with a steam superheater heating steam inlet, a steam superheater heating steam outlet, a steam superheater saturated steam inlet and a steam superheater superheated steam outlet. The electric superheater is connected in series to the corresponding pipeline of the steam superheater superheated steam outlet of the steam superheater. One end of the steam pipe for heating the steam accumulator is connected to the corresponding pipe of the steam superheater heating steam inlet, the other end of the steam pipe for heating the steam of the bypass steam superheater is connected to the corresponding pipe of the steam superheater heating steam outlet, the steam superheater heating steam outlet is connected to the evaporator, the evaporator in the saturated steam system supplies heat storage steam to the steam accumulator system through the steam accumulator heating steam inlet, the feed water preheater in the saturated steam system provides initial filling water to the steam accumulator system through the steam accumulator filling water inlet, and the steam accumulator system provides saturated steam to the steam superheater through a pipe connecting the steam accumulator heating steam outlet and the saturated steam inlet of the steam superheater.

3. A nuclear power unit steam energy storage heating system according to claim 2, characterized in that: The evaporator is provided with an evaporator heating steam inlet, an evaporator heating steam outlet, an evaporator water inlet and an evaporator saturated steam outlet; the feedwater preheater is provided with a feedwater preheater heating water inlet, a feedwater preheater water outlet and a steam accumulator water filling outlet; the steam superheater heating steam outlet is connected to the evaporator heating steam inlet, the evaporator heating steam outlet is connected to the feedwater preheater heating water inlet, the evaporator saturated steam outlet is connected to the steam accumulator heating steam inlet, the feedwater preheater water outlet is connected to the evaporator water inlet, and the steam accumulator water filling outlet is connected to the steam accumulator water filling inlet.

4. A nuclear power unit steam energy storage heating system according to claim 2, characterized in that: The evaporator is provided with an evaporator heating steam inlet, an evaporator heating steam outlet, an evaporator water inlet and an evaporator saturated steam outlet, the feedwater preheater is provided with a feedwater preheater heating water inlet and a feedwater preheater water outlet, the steam superheater heating steam outlet is connected to the evaporator heating steam inlet, the evaporator heating steam outlet is connected to the feedwater preheater heating water inlet, the evaporator saturated steam outlet is connected to the steam accumulator heating steam inlet, one way of the pipeline corresponding to the feedwater preheater water outlet is connected to the evaporator water inlet, and the other way of the pipeline corresponding to the feedwater preheater water outlet is connected to the steam accumulator water filling inlet.

5. A nuclear power unit steam energy storage heating system according to claim 1, characterized in that: The saturated steam system includes an evaporator and a feedwater preheater. The superheated steam system includes a steam superheater, a bypass steam superheater heating steam pipeline and an electric superheater. The steam superheater is used to use the main steam or steam turbine extraction steam to heat the saturated steam into superheated steam and supply it to the user. The electric superheater is used to supply superheated steam to the user when the main steam or steam turbine extraction steam of the nuclear power unit is unavailable. The steam superheater is provided with a steam superheater heating steam inlet, a steam superheater heating steam outlet, a steam superheater saturated steam inlet and a steam superheater superheated steam outlet. The electric superheater is provided with an electric superheater inlet and an electric superheater. outlet, the evaporator in the saturated steam system supplies heat storage steam to the steam accumulator system through the steam accumulator heating steam inlet, the feedwater preheater in the saturated steam system provides initial water filling to the steam accumulator system through the steam accumulator water filling inlet, one way of the corresponding pipeline of the steam accumulator heating steam outlet is connected to the pipeline connecting the saturated steam inlet of the steam superheater and the evaporator and is close to the saturated steam inlet side of the steam superheater, the other way of the corresponding pipeline of the steam accumulator heating steam outlet is connected to the electric superheater inlet, and the electric superheater outlet is connected to the corresponding pipeline of the superheated steam outlet of the steam superheater.

6. A nuclear power unit steam energy storage heating system according to claim 5, characterized in that: The evaporator is provided with an evaporator heating steam inlet, an evaporator heating steam outlet, an evaporator water inlet and an evaporator saturated steam outlet, the feedwater preheater is provided with a feedwater preheater heating water inlet, a feedwater preheater water outlet and a steam accumulator water filling outlet, one way of the pipeline corresponding to the evaporator saturated steam outlet is connected with the steam accumulator heating steam inlet, the other way of the pipeline corresponding to the evaporator saturated steam outlet is connected with the steam superheater saturated steam inlet, the steam accumulator water filling outlet is connected with the steam accumulator water filling inlet, the evaporator heating steam outlet is connected with the feedwater preheater heating water inlet, one end of the bypass steam superheater heating steam pipeline is connected to the pipeline corresponding to the steam superheater heating steam inlet, the other end of the bypass steam superheater heating steam pipeline is connected with the pipeline corresponding to the steam superheater heating steam outlet and then connected with the evaporator heating steam inlet.

7. A nuclear power unit steam energy storage heating system according to claim 5, characterized in that: It also includes a booster pump and a heat storage evaporator. The evaporator is provided with an evaporator heating steam inlet, an evaporator heating steam outlet, an evaporator water inlet and an evaporator saturated steam outlet, the feed water preheater is provided with a feed water preheater heating water inlet and a feed water preheater water outlet, the heat storage evaporator is provided with a heat storage evaporator heating steam inlet, a heat storage evaporator heating steam outlet, a heat storage heater feed water inlet and a heat storage heater steam outlet, one way of the pipeline corresponding to the feed water preheater water outlet is connected to the evaporator water inlet, the other way of the pipeline corresponding to the feed water preheater water outlet is connected to the booster pump, one way of the pipeline corresponding to the outlet of the booster pump is connected to the heat storage heater feed water inlet, the other way of the pipeline corresponding to the outlet of the booster pump is connected to the steam accumulator water filling inlet, the heat storage evaporator heating steam inlet is connected to the evaporator heating steam inlet, the evaporator heating steam outlet corresponding pipeline is connected to the feed water preheater heating water inlet after merging with the heat storage evaporator heating steam outlet corresponding pipeline, and the heat storage heater steam outlet is connected to the steam accumulator heating steam inlet.

8. A nuclear power unit steam energy storage heating system according to any one of claims 1 to 7, characterized in that: The saturated steam system also includes a feedwater heating and deoxygenating device. The feedwater preheater is provided with a feedwater preheater heating water outlet and a feedwater preheater water inlet. The feedwater heating and deoxygenating device is provided with a feedwater heating and deoxygenating device heating water inlet and a feedwater heating and deoxygenating device water outlet. The feedwater preheater provides a heating heat source to the feedwater heating and deoxygenating device via a pipeline connecting the feedwater preheater heating water outlet and the feedwater heating and deoxygenating device heating water inlet. The feedwater heating and deoxygenating device supplies preheated deoxygenated feed water to the feedwater preheater via a pipeline connecting the feedwater heating and deoxygenating device water outlet and the feedwater preheater water inlet.

9. A nuclear power unit steam energy storage heating system according to any one of claims 1 to 7, characterized in that: The steam accumulator system comprises at least one steam accumulator.

10. A nuclear power unit steam energy storage heating system according to any one of claims 1 to 7, characterized in that: At least one steam accumulator is a plurality of steam accumulators, some of which are in a high-pressure heat storage end state, and some of which are in a low-pressure heat release end state, to meet peak load regulation.

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