Steam-gas combined supply peak regulation system coupling steam heating and electric heating fused salt

Abstract

According to the steam-gas combined supply peak shaving system, steam heating and electric heating fused salt are coupled, and the overall efficiency, economical efficiency and energy quality are improved. The cold salt tank is connected with the cold salt pump; the cold salt pump is connected with the condensation section heat exchanger; the condensation section heat exchanger is connected with the overheating section heat exchanger; the high-pressure heating steam pipeline is connected with the superheat section heat exchanger; the superheat section heat exchanger is connected with the condensation section heat exchanger; the hot salt tank is connected with the hot salt pump; the hot salt pump is connected with the superheater, the superheater is connected with the kettle type evaporator, the kettle type evaporator is connected with the preheater, and the preheater is connected with the cold salt tank; a heat absorption side outlet of the overheating section heat exchanger is connected with an inlet of the electric heater; an outlet of the electric heater is connected with the hot salt tank; the water supply pipeline is connected with a water inlet of the preheater, a water outlet of the preheater is connected with a water inlet of the kettle-type evaporator, a steam outlet of the kettle-type evaporator is connected with a steam inlet of the superheater, and a steam outlet of the superheater is connected with the steam-driven air compressor system through a medium-pressure steam pipeline.

Description

Technical Field

[0001] The utility model relates to a steam-gas combined supply peak shaving system that couples steam heating and electric heating molten salt. Background Art

[0002] Since the dual-carbon policy, new energy represented by wind power and photovoltaic power has developed rapidly. However, the regional characteristics of wind power and photovoltaic power and their instability with climate change have brought huge challenges to the power grid. In order to absorb green power from wind and photovoltaic as much as possible, when wind power and photovoltaic power are in large output, the power grid should try to absorb green power as much as possible. At this time, the load of coal-fired power units is reduced. When the load of wind power and photovoltaic power is low, coal-fired power units need to generate electricity to the maximum extent to improve power generation capacity to meet the power consumption demand of the power grid. That is, the power grid has higher requirements for the deep peak shaving and peak topping capabilities of coal-fired power plants.

[0003] Many coal-fired power station units have industrial heat loads, and general heat loads need to be supplied continuously and stably. Therefore, when the power grid requires the power plant to reduce the load, due to the requirements of heating parameters and flow rate, the power station cannot reduce the load to 30%, which cannot meet the requirements of the power grid. When at the peak, due to the heat load, full-capacity power generation cannot be achieved, and the contradiction is relatively prominent. At present, the overall efficiency of the electrothermal molten salt scheme is relatively low. For the steam molten salt scheme, limited by the steam saturation point temperature, the temperature of the molten salt cannot be increased too much, and the energy quality has decreased. When there is a demand for compressed air and steam supply from the outside, the efficiency of the steam-driven air compressor is low, and the overall economy is poor. Content of the Utility Model

[0004] The purpose of the utility model is to overcome the above-mentioned deficiencies existing in the prior art, and to provide a steam-gas combined supply peak shaving system that couples steam heating and electric heating molten salt with a reasonable structural design, which improves the overall efficiency and economy and improves the energy quality.

[0005] The technical solution adopted by the present utility model to solve the above problems is as follows: A steam-gas combined supply peak shaving system that couples steam heating and electric heating of molten salt, comprising a cold salt tank, a hot salt tank, a cold salt pump, a hot salt pump, a condensation section heat exchanger, a superheat section heat exchanger, a superheater, a kettle-type evaporator, a preheater, a high-pressure heating steam pipeline, and a steam-driven air compressor system; the cold salt tank is connected to the cold salt pump; the cold salt pump is connected to the inlet of the heat absorption side of the condensation section heat exchanger; the outlet of the heat absorption side of the condensation section heat exchanger is connected to the inlet of the heat absorption side of the superheat section heat exchanger; the high-pressure heating steam pipeline is connected to the inlet of the heating side of the superheat section heat exchanger, and the outlet of the heating side of the superheat section heat exchanger is connected to the inlet of the heating side of the condensation section heat exchanger; the hot salt tank is connected to the hot salt pump; the outlet of the hot salt pump is connected to the molten salt inlet of the superheater, the molten salt outlet of the superheater is connected to the molten salt inlet of the kettle-type evaporator, the molten salt outlet of the kettle-type evaporator is connected to the molten salt inlet of the preheater, and the molten salt outlet of the preheater is connected to the cold salt tank; characterized in that: it further comprises an electric heater, a feed water pipeline, and a medium-pressure steam pipeline; the outlet of the heat absorption side of the superheat section heat exchanger is connected to the inlet of the electric heater; the outlet of the electric heater is connected to the hot salt tank; the feed water pipeline is connected to the water inlet of the preheater, the water outlet of the preheater is connected to the water inlet of the kettle-type evaporator, the steam outlet of the kettle-type evaporator is connected to the steam inlet of the superheater, and the steam outlet of the superheater is connected to the steam-driven air compressor system through the medium-pressure steam pipeline.

[0006] The present utility model further comprises a booster pump, and the outlet of the heating side of the condensation section heat exchanger is connected to the booster pump through a condensate pipeline.

[0007] The present utility model further comprises a temperature-adjusting molten salt pipeline, a low-temperature molten salt pipeline, and a hot molten salt pipeline; the cold salt pump is connected to the inlet of the heat absorption side of the condensation section heat exchanger through the low-temperature molten salt pipeline; the outlet of the hot salt pump is connected to the molten salt inlet of the superheater through the hot molten salt pipeline; one end of the temperature-adjusting molten salt pipeline is connected to the low-temperature molten salt pipeline, and the other end is connected to the hot molten salt pipeline.

[0008] The present utility model further comprises a desuperheater and desuperheating regulator, the steam inlet of the desuperheater and desuperheating regulator is connected to the high-pressure heating steam pipeline, the steam outlet is connected to the medium-pressure steam pipeline, and the water inlet is connected to the feed water pipeline.

[0009] A feed water pump is installed on the feed water pipeline of the present utility model.

[0010] The steam-driven air compressor system of the present utility model comprises a steam turbine and an air compressor, and the steam turbine is connected to the air compressor; the steam outlet of the superheater is connected to the steam inlet of the steam turbine through the medium-pressure steam pipeline, and a low-pressure steam pipeline is connected to the steam outlet of the steam turbine.

[0011] Compared with the prior art, the present utility model has the following advantages and effects:

[0012] (1) Adopt molten salt energy storage technology. When the power station conducts deep regulation, store the boiler steam energy in the molten salt, reduce the boiler load, and at the same time configure an electric heater to improve the temperature quality of the molten salt, reduce the external power supply of the steam turbine, and store it in the hot salt tank; at the peak of the power station, utilize the energy released by the molten salt energy storage to generate medium-pressure parameter steam and send it to the steam-driven air compressor to achieve steam-gas combined supply. The original extraction condensing unit of the power station is relieved of heat supply, and full-capacity power generation is achieved.

[0013] (2) Compared with only using steam to heat the molten salt, the heating temperature of the molten salt is limited by the steam saturation point temperature. By adopting the coupling method of steam heating and electric heating, the parameters and quality of the molten salt can be improved. After heat exchange between the molten salt and steam-water, the generated steam temperature rises, which can greatly improve the efficiency of the steam-driven air compressor, and the overall efficiency of the whole plant is relatively high. At the same time, it can also achieve deep peak shaving of the external power supply of the steam turbine.

[0014] (3) After the temperature of the molten salt is increased, the temperature difference of the molten salt increases, resulting in a reduction in the amount of molten salt used, a reduction in the molten salt storage tank, and a reduction in the flow rate of the molten salt pump. Accordingly, the investment in equipment such as molten salt, molten salt tank, and molten salt pump is reduced to a certain extent.

[0015] (4) Adopt a steam-driven air compressor system to convert the steam and electric energy during deep regulation into steam and compressed air at the peak moment of the power station through the molten salt energy storage device, realizing the superposition of the benefits of the two, and greatly improving the overall economy of the project.

[0016] (5) Considering the stability of the externally supplied compressed air, a desuperheater bypass is set up to achieve safe, stable and continuous external supply of compressed air. Description of the Drawings

[0017] Figure 1 is a schematic structural diagram of an embodiment of the present invention. Detailed Embodiment

[0018] The present invention will be further described in detail below with reference to the drawings and through embodiments. The following embodiments are explanations of the present invention, and the present invention is not limited to the following embodiments.

[0019] The embodiments of the present utility model include a cold salt tank 1, a hot salt tank 2, a cold salt pump 3, a hot salt pump 4, a condensation section heat exchanger 5, a superheat section heat exchanger 6, an electric heater 7, a booster pump 8, a desuperheater 9, a superheater 10, a kettle-type evaporator 11, a preheater 12, a feed water pump 13, a steam-driven air compressor system, a high-pressure heating steam pipeline 101, a heating steam pipeline at the inlet of the condensation section heat exchanger 102, a condensate pipeline 103, a low-temperature molten salt pipeline 104, a medium-temperature molten salt pipeline 105, a sub-high-temperature molten salt pipeline 106, a high-temperature molten salt pipeline 107, a temperature-regulating molten salt pipeline 108, a hot molten salt pipeline 109, a molten salt pipeline at the outlet of the superheater 110, a molten salt pipeline at the outlet of the evaporator 111, a cold molten salt pipeline 112, a feed water pipeline 114, a desuperheating water pipeline 113, a high-temperature water pipeline 115, a saturated water pipeline 116, a medium-pressure steam pipeline 117, and a low-pressure steam pipeline 118.

[0020] The cold salt tank 1 is connected to the cold salt pump 3; the cold salt pump 3 is connected to the inlet of the heat absorption side of the condensation section heat exchanger 5 through the low-temperature molten salt pipeline 104; the outlet of the heat absorption side of the condensation section heat exchanger 5 is connected to the inlet of the heat absorption side of the superheat section heat exchanger 6 through the medium-temperature molten salt pipeline 105; the outlet of the heat absorption side of the superheat section heat exchanger 6 is connected to the inlet of the electric heater 7 through the sub-high-temperature molten salt pipeline 106; the outlet of the electric heater 7 is connected to the hot salt tank 2 through the high-temperature molten salt pipeline 107.

[0021] The high-pressure heating steam pipeline 101 is connected to the inlet of the heating side of the superheat section heat exchanger 6, and the outlet of the heating side of the superheat section heat exchanger 6 is connected to the inlet of the heating side of the condensation section heat exchanger 5 through the heating steam pipeline at the inlet of the condensation section heat exchanger 102; the inlet of the heating side of the condensation section heat exchanger 5 is connected to the condensate pipeline 103, and a booster pump 8 is installed on the condensate pipeline 103. The condensate of the condensation section heat exchanger 5 is sent to the main feed water pipe network after being pressurized by the booster pump 8.

[0022] The hot salt tank 2 is connected to the hot salt pump 4; the outlet of the hot salt pump 4 is connected to the molten salt inlet of the superheater 10 through the hot molten salt pipeline 109. The molten salt outlet of the superheater is connected to the molten salt inlet of the kettle-type evaporator 11 through the molten salt pipeline at the outlet of the superheater 110. The molten salt outlet of the kettle-type evaporator 11 is connected to the molten salt inlet of the preheater 12 through the molten salt pipeline at the outlet of the evaporator 111. The molten salt outlet of the preheater 12 is connected to the cold salt tank 1 through the cold molten salt pipeline 112.

[0023] One end of the temperature-regulating molten salt pipeline 108 is connected to the low-temperature molten salt pipeline 104, and the other end is connected to the hot molten salt pipeline 109 for adjusting the temperature of the molten salt at the outlet of the hot molten salt pump.

[0024] The feed water pipe 114 is connected to the water inlet of the preheater 12, and a feed water pump 13 is installed on the feed water pipe 114. The water outlet of the preheater 12 is connected to the water inlet of the kettle - type evaporator 11 through the high - temperature water pipe 115. The steam outlet of the kettle - type evaporator 11 is connected to the steam inlet of the superheater 10 through the saturated steam pipe 116. The steam outlet of the superheater 10 is connected to the steam - driven air compressor system through the medium - pressure steam pipe 117.

[0025] The steam - driven air compressor system includes a steam turbine 14, a gearbox 15 and an air compressor 16. The steam turbine 14 is connected to the air compressor 16 through the gearbox 15. An air pipe 119 is connected to the inlet of the air compressor 16, and a compressed air pipe 120 is connected to the outlet of the air compressor 16. The steam outlet of the superheater 10 is connected to the steam inlet of the steam turbine 14 through the medium - pressure steam pipe 117, and the steam outlet of the steam turbine 14 is connected to the low - pressure steam pipe 118.

[0026] The steam inlet of the desuperheater - pressure reducer 9 is connected to the high - pressure heating steam pipe 101, the steam outlet is connected to the medium - pressure steam pipe 117, and the water inlet is connected to the feed water pipe 114 through the desuperheating water pipe 113.

[0027] The operation method of the present utility model is as follows:

[0028] During the deep load regulation of the power plant, the high - pressure heating steam of the power plant is sent into the high - pressure heating steam pipe 101, and is successively sent to the superheat section heat exchanger 6 and the condensation section heat exchanger 5 to heat the molten salt. After the steam condenses into condensate water, it is pressurized by the booster pump 8 and sent to the main feed water pipe network. The molten salt in the cold salt tank 1 is pumped out after being pressurized by the cold salt pump 3, sent to the condensation section heat exchanger 5 and the superheat section heat exchanger 6 to absorb heat and become sub - high - temperature molten salt, and then the temperature quality of the molten salt is improved by the electric heater 7 and stored in the hot salt tank 2, realizing energy storage and deep peak shaving of the power plant boiler and steam turbine.

[0029] During the peak load of the power plant, the molten salt in the hot salt tank 2 is pumped out after being pressurized by the hot salt pump 4, and is successively sent to the superheater 10, the kettle - type evaporator 11 and the preheater 12. After releasing heat, it becomes cold molten salt and is stored in the cold salt tank 1. The water from the deaerator of the power plant is sent into the feed water pipe 114, and after being pressurized by the feed water pump 13, it successively absorbs heat through the preheater 12, the kettle - type evaporator 11 and the superheater 10 and becomes medium - pressure steam. The medium - pressure steam is sent to the steam - driven air compressor system to drive the steam turbine 14. The back - pressure exhaust steam of the steam turbine 14 is sent to the steam pipe network through the low - pressure steam pipe 118, and the air compressor 16 generates compressed air, simultaneously realizing the generation and supply of low - pressure steam and compressed air.

[0030] This system does not configure an additional temperature - regulating pump. By using the temperature - regulating molten salt pipe 108, the molten salt at the outlet of the cold salt pump 3 is sent to the hot molten salt pipe 109 for molten salt temperature regulation under startup and low - load conditions.

[0031] Considering the stable supply of externally supplied compressed air, a desuperheating and pressure reducing valve 9 is provided in this system. When the molten salt system is not operating, the high-pressure heating steam is converted into medium-pressure steam through the bypass of the desuperheating and pressure reducing valve 9 and sent to the steam-driven air compressor system to achieve continuous external air supply.

[0032] In addition, it should be noted that for the specific embodiments described in this specification, the shapes and names of their components can be different. The above content described in this specification is only an example of the structure of the present invention. Any equivalent changes or simple changes made according to the structure, features, and principles described in the patent concept of the present invention are included in the protection scope of the patent of the present invention. Those skilled in the art of the present invention can make various modifications, supplements, or use similar methods to replace the specific embodiments described, as long as they do not deviate from the structure of the present invention or exceed the scope defined by this claim book, they should fall within the protection scope of the present invention.

Claims

1. A steam-gas cogeneration peak-shaving system for coupling steam heating and electric heating of molten salt, comprising a cold salt tank, a hot salt tank, a cold salt pump, a hot salt pump, a condensation section heat exchanger, a superheating section heat exchanger, a superheater, a kettle evaporator, a preheater, a high-pressure heating steam pipeline and a steam-driven air compressor system; the cold salt tank is connected to the cold salt pump; the cold salt pump is connected to the heat absorption side inlet of the condensation section heat exchanger; the heat absorption side outlet of the condensation section heat exchanger is connected to the heat absorption side inlet of the superheating section heat exchanger; the high-pressure heating steam pipeline is connected to the heating side inlet of the superheating section heat exchanger, and the heating side outlet of the superheating section heat exchanger is connected to the heating side inlet of the condensation section heat exchanger; the hot salt tank is connected to the hot salt pump; the outlet of the hot salt pump is connected to the molten salt inlet of the superheater, the molten salt outlet of the superheater is connected to the molten salt inlet of the kettle evaporator, the molten salt outlet of the kettle evaporator is connected to the molten salt inlet of the preheater, and the molten salt outlet of the preheater is connected to the cold salt tank; characterized in that: It also includes an electric heater, a water supply pipe and a medium-pressure steam pipe; the heat absorption side outlet of the superheater heat exchanger is connected to the inlet of the electric heater; the outlet of the electric heater is connected to the hot salt tank; the water supply pipe is connected to the water inlet of the preheater, the water outlet of the preheater is connected to the water inlet of the kettle evaporator, the steam outlet of the kettle evaporator is connected to the steam inlet of the superheater, and the steam outlet of the superheater is connected to the steam-driven air compressor system through the medium-pressure steam pipe.

2. The steam-gas combined supply peak-shaving system for coupling steam heating and electric heating of molten salt according to claim 1 is characterized in that: It also includes a booster pump, and the heating side outlet of the condensation section heat exchanger is connected to the booster pump through a condensate water pipeline.

3. The steam-gas combined supply peak-shaving system for coupling steam heating and electric heating of molten salt according to claim 1 is characterized in that: It also includes a temperature-regulating molten salt pipeline, a low-temperature molten salt pipeline and a hot molten salt pipeline; the cold salt pump is connected to the heat absorption side inlet of the condensation section heat exchanger through the low-temperature molten salt pipeline; the outlet of the hot salt pump is connected to the molten salt inlet of the superheater through the hot molten salt pipeline; one end of the temperature-regulating molten salt pipeline is connected to the low-temperature molten salt pipeline, and the other end is connected to the hot molten salt pipeline.

4. The steam-gas combined supply peak-shaving system for coupling steam heating and electric heating of molten salt according to claim 1 is characterized in that: It also includes a temperature reducer and pressure reducer, the steam inlet of the temperature reducer and pressure reducer is connected to the high-pressure heating steam pipeline, the steam outlet is connected to the medium-pressure steam pipeline, and the water inlet is connected to the water supply pipeline.

5. The steam-gas combined supply peak-shaving system for coupling steam heating and electric heating of molten salt according to claim 1 is characterized in that: A water supply pump is installed on the water supply pipeline.

6. The steam-gas combined supply peak-shaving system for coupling steam heating and electric heating of molten salt according to claim 1 is characterized in that: The steam-driven air compressor system comprises a steam turbine and an air compressor, wherein the steam turbine is connected to the air compressor; the steam outlet of the superheater is connected to the steam inlet of the steam turbine through a medium-pressure steam pipeline, and the steam outlet of the steam turbine is connected to a low-pressure steam pipeline.

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