A method for realizing multi-parameter clean steam supply for nuclear energy peak regulation and thermal storage

Abstract

The present invention provides a method for realizing nuclear energy peak-shaving heat storage and multi-parameter clean steam supply, the method comprising the following steps: step S1, dividing the high-pressure wet steam generated by the steam generator into three paths, the first path entering the high-pressure cylinder of the steam turbine, the second path entering the steam-water separation reheater to heat the wet steam discharged from the high-pressure cylinder of the steam turbine, and the third path entering the high-pressure electric heat storage device; step S2, conveying the heated steam to the temperature reducing and pressure reducing device through a pipeline; step S3, the steam discharged from the high-pressure cylinder of the steam turbine is divided into two paths, the first path entering the steam-water separation reheater to be heated and then entering the low-pressure cylinder of the steam turbine, and the second path of steam entering the low-pressure electric heat storage device to heat the steam; step S4, the steam discharged from the low-pressure cylinder of the steam turbine is cooled by the condenser and then enters the condensate pump, and then enters the steam generator after passing through the steam-water circulation component to complete the steam-water circulation; the present invention can realize industrial steam with multiple parameters according to the external heat load demand.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear energy clean heating, and in particular to a method for realizing nuclear energy peak-shaving heat storage multi-parameter clean steam supply. Background Art

[0002] Large-capacity nuclear power units are usually pure condensing units. The main steam temperature parameters of nuclear power plants based on pressurized water reactors are low. The steam generated by the nuclear island is wet steam. If the heat generated by the nuclear island only enters the steam turbine for power generation, most of the heat will be taken away through the cold-end circulating water system, resulting in low thermal efficiency of the entire plant and causing greater thermal pollution to the environment. The heat generated by the nuclear island is not fully utilized.

[0003] With the clean and low-carbon transformation of the energy and power system, nuclear power, as one of the basic power sources of the zero-carbon energy system, is playing an increasingly prominent role in supporting the power grid to absorb a high proportion of new energy. The coordinated development of nuclear power and other new energy sources is accelerating. Therefore, nuclear power units are required to have a certain peak-shaving capacity to meet the needs of more new energy sources connected to the power grid.

[0004] Cogeneration units generally use the new steam generated by the boiler to reduce temperature and pressure, and extract steam in a certain section of the turbine or other multiple ways to achieve external heat supply. The steam must have a certain degree of superheat to meet the needs of long-distance transportation, and the steam will not condense into water during transportation. With the implementation of the dual carbon goals, it is becoming increasingly difficult to approve industrial steam supply projects using traditional coal-fired methods. Existing units will gradually face the trend of being shut down and replaced by new energy. Nuclear power is a clean energy source. The steam generated by the nuclear island replaces the traditional coal-fired unit boiler to drive the steam turbine generator set to generate electricity. There is no carbon emission in the process of electricity production. However, due to the operating characteristics of the nuclear island itself, peak regulation is relatively difficult. The steam generated by the nuclear island is maintained in a saturated state, but the amount of steam is very large. With the development of electric heat storage technology, electric heat storage can store excess electricity during peak regulation periods in electric heat storage devices, making it possible for nuclear power plants to provide high-quality industrial steam. Under the premise of ensuring the normal operation of the nuclear island, a certain range of power peak regulation can be carried out, further improving the thermal efficiency of nuclear power plants. This technology can also be used in the frequency regulation auxiliary service market and the peak regulation auxiliary service market. The depth of peak regulation is proportional to the external heat load demand. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a method for realizing industrial steam with multiple parameters according to external heat load requirements.

[0006] The present invention is implemented by the following method: a method for realizing nuclear energy peak shaving heat storage multi-parameter clean steam supply, the method comprising the following steps:

[0007] Step S1, a steam generator generates high-pressure wet steam, and the high-pressure wet steam generated by the steam generator is divided into three paths, the first path enters the high-pressure cylinder of the steam turbine, the second path enters the steam-water separation reheater to heat the wet steam discharged from the high-pressure cylinder of the steam turbine, and the third path enters the high-pressure electric heat storage device to heat the steam;

[0008] Step S2, transporting the heated steam to the desuperheater and pressure reducer through a pipeline, adjusting the pressure of the steam in the desuperheater and pressure reducer according to external steam parameters, and introducing the steam temperature to the high-pressure feed water pump through a first introduction pipe;

[0009] Step S3, the steam discharged from the high-pressure cylinder of the steam turbine is divided into two paths, the first path enters the steam-water separation reheater to be heated and then enters the low-pressure cylinder of the steam turbine, and the second path of steam enters the low-pressure electric heat storage device to heat the steam;

[0010] Step S4: The steam discharged from the low-pressure cylinder of the steam turbine is cooled by the condenser and enters the condensate pump, and then enters the steam generator after passing through the steam-water circulation component to complete the steam-water circulation, thereby realizing steam heating and achieving peak regulation for the nuclear power unit.

[0011] Furthermore, the steam generator is provided with three steam outlets, the first steam outlet is connected to the steam inlet of the high-pressure cylinder of the steam turbine, the second steam outlet is connected to the steam inlet of the steam-water separation reheater, and the third steam outlet is connected to the high-pressure electric heat storage device via an input pipeline; the steam outlet of the high-pressure electric heat storage device is connected to the temperature reducer and pressure reducer via a conveying pipeline, and two steam outlet pipes are provided on the high-pressure cylinder of the steam turbine, the first steam outlet pipe is connected to the steam-water separation reheater, the steam outlet of the steam-water separation reheater is connected to the low-pressure cylinder of the steam turbine, the steam outlet of the low-pressure cylinder of the steam turbine is connected to the condenser, the condenser cools the steam and enters the condensate pump, the condensate pump is connected to the steam generator via a steam-water circulation component, and the second steam outlet pipe is connected to the low-pressure electric heat storage device.

[0012] Furthermore, the steam outlet of the low-pressure electric heat storage device is connected to the desuperheater via a delivery pipeline, a delivery branch is connected to the delivery pipeline, the delivery branch is connected to the pressure matcher, and a delivery branch pipe is connected to the delivery pipeline, the delivery branch pipe is connected to the pressure matcher.

[0013] Furthermore, the steam-water circulation component in step S4 includes a low-pressure heater, a deaerator, a high-pressure feed water pump and a high-pressure heater. The water outlet of the condensate pump is connected to the low-pressure heater, the deaerator, the high-pressure feed water pump and the high-pressure heater in sequence through a pipeline and then enters the steam generator.

[0014] Furthermore, the temperature and pressure reducing device is connected to the outlet of the high-pressure water supply pump via a first guide pipe.

[0015] Furthermore, the second inlet pipe of the desuperheater is connected to the outlet of the condensate pump.

[0016] Furthermore, the high-voltage electric heat storage device and the low-voltage electric heat storage device are both electrically heated to electrically store steam, and the power supply is connected to the high-voltage electric heat storage device and the low-voltage electric heat storage device through the power supply line of the electric heat storage device via a circuit breaker.

[0017] The beneficial effects of the present invention are as follows: the present invention will further improve the efficiency of nuclear energy utilization. Taking a pressurized water reactor power plant as an example, its thermal efficiency is about 38%. After adopting the present invention to supply heat to the outside, every 1 ton of steam supplied to the outside will reduce carbon dioxide emissions by 0.34 tons, and the emission reduction effect is obvious; when the power grid has high requirements for the power load of the nuclear power plant, all the electricity generated by the steam turbine generator set is connected to the grid, and the electric heat storage device heats the steam with the heat it has stored, so that the electric heat storage device can work 24 hours a day and realize the peak regulation effect on the nuclear power unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the method flow of the present invention.

[0019] Figure 2 It is a schematic block diagram of the structural process of the present invention.

[0020] Among them: 1-steam generator, 2-steam turbine high-pressure cylinder, 3-steam turbine low-pressure cylinder, 4-condenser, 5-condensate pump, 6-low-pressure heater, 7-deaerator, 8-high-pressure feed water pump, 9-high-pressure heater, 10-steam-water separation reheater, 11-high-pressure electric heat storage device, 12-low-pressure electric heat storage device, 13-pressure matcher, 14-temperature and pressure reducer, 15-desuperheater, 16-transmission pipeline, 17-transmission pipeline, 18-transmission branch, 19-transmission branch, 20-first lead-in pipeline, 21-second lead-in pipeline, 22-circuit breaker, 23-electric heat storage device power supply line. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings.

[0022] See also Figure 1 As shown, the present invention provides an embodiment: a method for realizing multi-parameter clean steam supply for nuclear energy peak shaving and thermal storage, the method comprising the following steps:

[0023] Step S1, a steam generator generates high-pressure wet steam, and the high-pressure wet steam generated by the steam generator is divided into three paths, the first path enters the high-pressure cylinder of the steam turbine, the second path enters the steam-water separation reheater to heat the wet steam discharged from the high-pressure cylinder of the steam turbine, and the third path enters the high-pressure electric heat storage device to heat the steam;

[0024] Step S2, transporting the heated steam to the desuperheater and pressure reducer through a pipeline, adjusting the pressure of the steam in the desuperheater and pressure reducer according to external steam parameters, and introducing the steam temperature to the high-pressure feed water pump through a first introduction pipe;

[0025] Step S3, the steam discharged from the high-pressure cylinder of the steam turbine is divided into two paths, the first path enters the steam-water separation reheater to be heated and then enters the low-pressure cylinder of the steam turbine, and the second path of steam enters the low-pressure electric heat storage device to heat the steam;

[0026] Step S4: The steam discharged from the low-pressure cylinder of the steam turbine is cooled by the condenser and enters the condensate pump, and then enters the steam generator after passing through the steam-water circulation component to complete the steam-water circulation, thereby realizing steam heating and achieving peak regulation for the nuclear power unit.

[0027] The present invention will be further described below by a specific embodiment:

[0028] See also Figure 2 As shown, the high-pressure wet steam generated by the steam generator 1 is divided into three paths. The first path enters the high-pressure cylinder 2 of the steam turbine to drive the steam turbine generator set to generate electricity. The second path enters the steam-water separation reheater 10 to heat the wet steam discharged from the high-pressure cylinder 2 of the steam turbine. The third path enters the high-pressure electric heat storage device 11 through a pipeline. The electric heat storage device heats the steam, and the steam is converted from wet steam to steam with a certain degree of superheat, thereby improving the quality of the steam; the steam heated by the high-pressure electric heat storage device 11 enters the temperature reducing device 14 through a pipeline, and the steam in the temperature reducing device 14 is slightly adjusted according to the external steam parameters. The steam temperature is connected to the high-pressure feed water pump 8 through the first lead-in pipeline 20, thereby realizing temperature regulation.

[0029] The wet steam discharged from the high-pressure cylinder 2 of the steam turbine is divided into two paths. The first path enters the steam-water separation reheater 10 and is heated before entering the low-pressure cylinder 3 of the steam turbine to drive the steam turbine generator set to generate electricity. The steam discharged from the low-pressure cylinder 3 of the steam turbine is cooled by the condenser 4 and enters the condensate pump 5. It passes through the low-pressure heater 6, the deaerator 7, the high-pressure feed water pump 8, and the high-pressure heater 9 in sequence before entering the steam generator 1 to complete the steam-water cycle. The second steam outlet pipeline enters the low-pressure electric heat storage device 12, and the electric heat storage device heats the steam. The steam is changed from wet steam to steam with a certain degree of superheat, thereby improving the quality of the steam. The heated steam enters the desuperheater 15 through the transmission pipeline 17 for slight temperature adjustment. The steam temperature is connected to the condensate pump 5 through the second lead-in pipeline 21, thereby achieving temperature regulation.

[0030] The low-pressure steam drawn out from the delivery pipeline 17 is introduced into the pressure matcher 13 through the delivery branch 18, and the high-pressure steam drawn out from the delivery pipeline 16 is introduced into the pressure matcher 13 through the delivery branch 19. The two steams are mixed in the pressure matcher 13 to form steam with a pressure between the high-pressure steam and the low-pressure steam, which meets the steam pressure required by the outside world.

[0031] The high-voltage electric heat storage device 11 and the low-voltage electric heat storage device 12 adopt an electric heating method, which can heat steam and store electric heat at the same time. The power supply is connected through the electric heat storage device power supply line 23 via the circuit breaker 22. When the power grid has a low demand for the electric load of the nuclear power plant, the circuit breaker 22 is closed, and part of the electricity generated by the steam turbine generator set is stored in the heat storage device in the form of heat. When the power grid has a high demand for the electric load of the nuclear power plant, the circuit breaker 22 is opened, and all the electricity generated by the steam turbine generator set is connected to the grid. The electric heat storage device heats the steam with the heat it has stored, and the electric heat storage device can work 24 hours a day and achieve a peak load regulation effect on the nuclear power unit.

[0032] The high-voltage electric heat storage device 11 and the low-voltage electric heat storage device 12 in the present invention are similar to the balance characteristics of the supply and demand relationship in the power production process. Thermal production also needs to maintain the balance between supply and demand by taking certain measures;

[0033] Solid thermal storage technology based on steam heat source stores the excess thermal energy carried by steam when the heat load is at a low point, and releases it when the heat load is at a peak point, thereby achieving the coupling of the supply and demand relationship of thermal production.

[0034] Basic principle: Solid thermal storage equipment consists of a heat storage system and a heat exchange system. When the system operates in a heat storage state, high-temperature and high-pressure steam enters the heat exchange pipe system and transfers heat energy to the solid thermal storage material to complete the heat storage process. When the system operates in a heat release state, the heating material is sent into the heat exchange pipe system to absorb heat from the thermal storage material and convert it into water or steam under specific parameters to be sent to heat users.

[0035] Heat release process: The excess steam is sent to the solid heat storage device, and after condensation, it is sent to the water storage tank for storage, or directly sent to the low-temperature heat user through the hydrophobic expansion tank.

[0036] Heat storage process: When steam releases heat, the energy storage body absorbs heat energy through heat conduction and converts it into internal energy for storage.

[0037] Heat extraction process: The heating medium is sent into the solid heat storage device to cool the energy storage body and take away the heat energy. In addition, the hot water stored in the water storage tank can be directly;

[0038] Heat extraction process: The heating medium is sent into the solid heat storage device, and the heat energy is taken away while cooling the energy storage body. In addition, the hot water stored in the water tank can be directly delivered to low-temperature heat users.

[0039] The steam generator, turbine high-pressure cylinder, turbine low-pressure cylinder, condenser, condensate pump, low-pressure heater, deaerator, high-pressure feed water pump, high-pressure heater, steam-water separation reheater, high-pressure electric heat storage device, low-pressure electric heat storage device, pressure matcher, temperature and pressure reducer, and desuperheater of the present invention are all prior arts, which are clearly understood by those skilled in the art and will not be described in detail herein.

[0040] In summary, the present invention makes full use of the characteristics of the thermal system and power supply system of the nuclear power plant, and supplies heat to the outside according to three parameters based on the flow, pressure and temperature characteristics of the main steam and reheated cold steam of the nuclear power plant, combined with the development of heat storage technology in recent years, and combined with the characteristics of the external demand for steam parameters: Parameter 1: When the steam parameter required by the outside world is high-pressure steam, the steam to be heated is extracted by drilling holes in the main steam pipeline, and then the steam is introduced into the high-pressure electric heat storage device. According to the actual demand of the external steam use point and considering the resistance along the way, the steam parameters at the plant boundary are reversed. A cooling and pressure reduction device is installed at the outlet of the electric heat storage device to appropriately adjust the steam parameters to meet the parameters required by the steam use boundary, and the cooling water is provided by the high-pressure feed water pump. , the electric heat storage device is provided by plant electricity; Parameter 2: When the steam parameters required by the outside world are low-pressure steam, the steam to be heated is extracted by drilling holes in the reheat cold steam pipeline, and then the steam is introduced into the low-pressure electric heat storage device. According to the actual needs of the external steam point and considering the resistance along the way, the steam parameters at the plant boundary are reversed. A desuperheating device is installed at the outlet of the electric heat storage device to appropriately adjust the steam parameters to meet the parameters required by the steam boundary. The desuperheating water is provided by the condensate pump, and the electric heat storage device is provided by plant electricity; Parameter 3: When the steam parameters required by the outside world are medium-pressure steam, the high-pressure steam and the low-pressure steam are mixed in the pressure matcher according to a certain proportion through the pressure matcher to achieve the steam parameters required by the outside world.

[0041] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A method for realizing multi-parameter clean steam supply for nuclear energy peak regulation and thermal storage, characterized by: The method comprises the following steps: Step S1: A steam generator generates high-pressure wet steam, and the high-pressure wet steam generated by the steam generator is divided into three paths: a first path enters a high-pressure cylinder of a steam turbine; a second path enters a steam-water separator reheater to heat the wet steam discharged from the high-pressure cylinder of the steam turbine; and a third path enters a high-pressure electric heat storage device to heat the steam; Step S2: transporting the heated steam to a desuperheater and pressure reducer through a pipeline, adjusting the steam pressure in the desuperheater and pressure reducer according to external steam parameters, and connecting the desuperheater and pressure reducer to a high-pressure water feed pump through a first inlet pipe; Step S3: The steam discharged from the high-pressure cylinder of the steam turbine is divided into two paths. The first path enters the steam-water separator reheater to be heated and then enters the low-pressure cylinder of the steam turbine. The second path enters the low-pressure electric heat storage device to heat the steam. Step S4: The steam discharged from the low-pressure cylinder of the steam turbine is cooled by the condenser and enters the condensate pump. After passing through the steam-water circulation component, it enters the steam generator to complete the steam-water circulation, thereby achieving steam heating and peak regulation for the nuclear power unit; The steam generator is provided with three steam outlets, the first steam outlet is connected to the steam inlet of the high-pressure cylinder of the steam turbine, the second steam outlet is connected to the steam inlet of the steam-water separator reheater, and the third steam outlet is connected to the high-pressure electric heat storage device via an input pipeline; the steam outlet of the high-pressure electric heat storage device is connected to the temperature reducing and pressure reducing device via a conveying pipeline, and two steam outlet pipes are provided on the high-pressure cylinder of the steam turbine, the first steam outlet pipe is connected to the steam-water separator reheater, the steam outlet of the steam-water separator reheater is connected to the low-pressure cylinder of the steam turbine, the steam outlet of the low-pressure cylinder of the steam turbine is connected to the condenser, the condenser cools the steam and enters the condensate pump, the condensate pump is connected to the steam generator via a steam-water circulation component, and the second steam outlet pipe is connected to the low-pressure electric heat storage device; The steam outlet of the low-pressure electric heat storage device is connected to the desuperheater via a delivery pipeline. The low-pressure steam is drawn out from the delivery pipeline and introduced into the pressure matcher through a delivery branch. The high-pressure steam is drawn out from the delivery pipeline and introduced into the pressure matcher through a delivery branch. The two steams are mixed in the pressure matcher to form steam with a pressure between the high-pressure steam and the low-pressure steam, meeting the steam pressure required by the outside world. The high-voltage electric heat storage device and the low-voltage electric heat storage device are both electrically heated to heat the steam and store heat electrically. The power supply is connected to the high-voltage electric heat storage device and the low-voltage electric heat storage device through the power supply line of the electric heat storage device via a circuit breaker.

2. The method for realizing multi-parameter clean steam supply for nuclear energy peak shaving and thermal storage according to claim 1, characterized in that: The steam-water circulation component in step S4 includes a low-pressure heater, a deaerator, a high-pressure feed water pump and a high-pressure heater. The water outlet of the condensate pump is connected to the low-pressure heater, the deaerator, the high-pressure feed water pump and the high-pressure heater in sequence through a pipeline and then enters the steam generator.

3. The method for realizing multi-parameter clean steam supply for nuclear energy peak shaving and thermal storage according to claim 1, characterized in that: The desuperheater is connected to the outlet of the condensate pump via a second guide pipe.

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