High-temperature heat storage peak regulation operation system for low-heating-value gas power generation

Abstract

The utility model discloses a high-temperature heat storage peak regulation operation system for low-heating-value gas power generation, and belongs to the technical field of power plant equipment. The high-temperature heat storage peak regulation operation system for low-heating-value gas power generation comprises a heating furnace heat storage unit which comprises a fused salt heating furnace and a low-temperature storage tank, the fused salt heating furnace is used for heating low-temperature fused salt in the fused salt heating furnace through heat generated after low-heating-value gas is burnt, and the low-temperature storage tank is used for storing the low-temperature fused salt; the high-temperature evaporation unit comprises a high-temperature storage tank, an evaporator and a steam pocket, and the high-temperature storage tank is used for storing high-temperature fused salt; the working medium inlet end of the evaporator communicates with the high-temperature storage tank, the working medium outlet end of the evaporator communicates with the low-temperature storage tank, the fused salt heating furnace is connected with the low-temperature storage tank, and the steam pocket is used for generating high-temperature saturated steam. The high-temperature heat storage peak regulation operation system for low-heating-value gas power generation can adjust the power generation power of a power plant and improve the stability of a power grid load, and is a load side energy storage operation mode for constructing a novel energy system in China.

Description

Technical Field

[0001] The utility model relates to the technical field of power plant equipment, in particular to a high-temperature heat storage peak-shaving operation system for low calorific value coal gas power generation. Background Art

[0002] With the rapid economic development and increasing demand for electricity in my country, the construction of a new energy system has become one of the important directions for the development of the country's energy sector, among which the rapid development of the power system is one of the primary and most important links in the new energy system. The proportion of new energy such as wind power and solar energy in my country's power grid is growing rapidly (it has exceeded coal-fired thermal power generation capacity by the end of 2023). In order to achieve the goal of carbon neutrality, higher requirements are put forward for the proportion and consumption of new energy power stations, which also leads to increasingly prominent peak-shaving contradictions in the power grid.

[0003] With the development and progress of industrial production and the overall social economic level, the society's demand for electric energy continues to grow, which has led to the continuous expansion of power grid capacity and great changes in the electricity consumption structure, which has increased the peak-to-valley difference of major power grids. In general, the peak-to-valley difference of major power grids is increasing, and the contradiction between the peak-to-valley capacity of the power grid and the objective peak-to-valley need is very sharp. With the large-scale construction and grid connection of wind power and photovoltaic power generation in the past decade, the country's macroeconomic regulation and effective control of production energy consumption indicators of high-energy-consuming enterprises, the peak-to-valley electricity price difference of the power grid has become more urgent, which has further increased, and this has also provided opportunities for load-side energy storage, especially large industrial load-side energy storage.

[0004] Blast furnace gas in iron and steel metallurgical production is a typical low-calorific value by-product of industrial processes. Except for a small amount of gas used for heating in metallurgical production, the remaining large amount of gas is almost all used for thermal power generation.

[0005] The power generation process system of low calorific value coal gas (such as blast furnace gas, coke oven gas, lignite tail gas, etc.) produced as a by-product of existing process industries is affected by the fluctuation of gas production stability during operation. During operation, the power generation can only be determined by the gas flow rate, and the power generation changes with the gas production. The gas production is a by-product of the main production system and changes with the load of the main production system. Therefore, if the main production system wants to increase the load during the night-time off-peak period, the amount of by-product coal gas will inevitably increase. However, the calorific value of coal gas is low and the storage capacity is very small. It can only be processed and converted into power generation in a timely manner according to the gas production. However, the electricity price during the night-time off-peak period is low, and the extra electricity generated cannot form a good economic value. That is, the conventional production mode of "generating electricity as soon as it is produced" of coal gas cannot adapt to (tap the potential of) the current policy dividends of "peak-valley electricity prices" and "peak shaving and valley filling" of the power grid, and has the disadvantages of high operation and maintenance costs and low system efficiency due to the small installed capacity of the power generation system. Utility Model Content

[0006] The purpose of the utility model is to overcome the problems in the prior art and to provide a high-temperature heat storage peak-shaving operation system for low-calorific value coal gas power generation, which can be deeply coupled with the original coal gas power generation system, can recycle the low-calorific value coal gas generated during the operation of the power plant, and perform auxiliary power generation during peak electricity consumption periods, regulate the power generation power of the power plant, and improve the stability of the power grid load.

[0007] The utility model provides a high-temperature heat storage peak-shaving operation system for low calorific value coal gas power generation, comprising:

[0008] The heating furnace heat storage unit includes a molten salt heating furnace and a low-temperature storage tank. The molten salt heating furnace is connected to the gas main of the original gas power generation system. The molten salt heating furnace is used to heat the low-temperature molten salt inside it by using the heat generated by the combustion of low-calorific value gas. The low-temperature storage tank is used to store the low-temperature molten salt. The low-temperature storage tank is connected to the molten salt heating furnace;

[0009] The high-temperature evaporation unit includes a high-temperature storage tank, an evaporator and a steam drum. The high-temperature storage tank is connected to the molten salt heating furnace and is used to store high-temperature molten salt. The working fluid inlet end of the evaporator is connected to the high-temperature storage tank, and the working fluid outlet end of the evaporator is connected to the low-temperature storage tank. The steam drum is connected to the evaporator and is used to generate high-temperature saturated steam. The steam drum is connected to the steam main of the raw coal gas power generation system.

[0010] Preferably, the molten salt heating furnace is equipped with a burner, the burner is connected to the gas main, the burner is connected to a waste heat exchanger through the molten salt heating furnace, the water inlet of the waste heat exchanger is connected to the deoxygenated water supply pipe of the original gas power generation system, the water outlet of the waste heat exchanger is connected to the deoxygenated water return pipe of the original gas power generation system, and the waste heat exchanger is used to utilize the waste heat of the flue gas discharged by the burner to heat the deoxygenated water.

[0011] Preferably, the air inlet of the waste heat exchanger is connected to the burner, and the air outlet of the waste heat exchanger is connected to an air preheater, which is connected to the blower pipe of the original gas power generation system. The air outlet of the air preheater is connected to the air inlet of the burner. The air preheater is used to utilize the waste heat of the flue gas discharged from the waste heat exchanger to heat the air entering the burner.

[0012] Preferably, the air preheater includes a first air supply port, a second air supply port, a first exhaust port and a second exhaust port, the first air supply port is connected to the blower pipe, the first exhaust port is connected to the air inlet of the burner, the second air supply port is connected to the air outlet of the waste heat exchanger, the second exhaust port is connected to a gas preheater, the gas preheater is connected to the flue gas outlet pipe of the original gas power generation system, the air inlet of the gas preheater is connected to the gas main of the original gas power generation system, the air outlet of the gas preheater is connected to the air inlet of the burner, and the gas preheater is used to utilize the waste heat of the flue gas discharged from the air preheater to heat the gas entering the burner.

[0013] Preferably, a superheater and a reheater are provided between the evaporator and the high-temperature storage tank, the inlets of the superheater and the reheater are both connected to the high-temperature storage tank, the outlets of the superheater and the reheater are both connected to the evaporator, the air inlet of the superheater is connected to the steam drum, the air outlet of the superheater is connected to the steam main, the superheater is used to heat the steam from the steam drum to the steam main, the air inlet of the reheater is connected to the reheat steam return pipe of the original gas-fired power generation system, the air outlet of the reheater is connected to the reheat steam outlet pipe of the original gas-fired power generation system, and the reheater is used to heat the steam from the reheat steam return pipe to the reheat steam outlet pipe.

[0014] Preferably, a first one-way valve is provided between the air outlet of the superheater and the steam main pipe, the first one-way valve is used for one-way communication from the air outlet of the superheater to the steam main pipe, a second one-way valve is provided between the air inlet of the reheater and the reheated steam return pipe, the second one-way valve is used for one-way communication from the reheated steam return pipe to the air inlet of the reheater, a third one-way valve is provided between the air outlet of the reheater and the reheated steam outlet pipe, the third one-way valve is used for one-way communication from the air outlet of the reheater to the reheated steam outlet pipe.

[0015] Preferably, a feed water preheater is provided between the evaporator and the low-temperature storage tank, the inlet of the feed water preheater is connected to the evaporator, the outlet of the feed water preheater is connected to the low-temperature storage tank, and is connected to the high-pressure feed water main of the original gas power generation system, the water outlet of the feed water preheater is connected to the steam drum, and the feed water preheater is used to heat the water entering the steam drum.

[0016] Preferably, a bypass valve is connected in parallel to the waste heat exchanger, one end of the bypass valve is connected to the air inlet of the waste heat exchanger, and the other end of the bypass valve is connected to the air outlet of the waste heat exchanger.

[0017] Preferably, a low-pressure water regulating valve group is provided between the water inlet of the waste heat exchanger and the deoxygenated water supply pipe, and a pressure stabilizing detector is provided between the water outlet of the waste heat exchanger and the deoxygenated water return pipe.

[0018] Preferably, a high-pressure water regulating valve group is provided between the water inlet of the feed water preheater and the high-pressure water feed main.

[0019] Compared with the prior art, the beneficial effects of the utility model are as follows: a high-temperature heat storage and peak-shaving operation system for low calorific value gas power generation of the utility model can be deeply coupled with the original gas power generation system, and can adapt the low calorific value gas used in the operation of the power plant to the "peak shaving and valley filling" mode of the power grid, and perform auxiliary power generation during peak electricity consumption periods, adjust the power generation power of the power plant, improve the stability of the power grid load, and increase the economy of the low calorific value gas power plant. It is a load-side energy storage operation mode for the country to build a new energy system.

[0020] By setting up a waste heat heat exchanger, the waste heat of the flue gas generated by the burner can be used to heat the deoxygenated water flowing into the deoxygenated water supply pipe, thereby improving the energy utilization rate of the entire system, improving the energy efficiency of the entire system, and saving energy and protecting the environment. By setting up an air preheater, the air temperature entering the burner can be increased, so that the waste heat of the flue gas generated by the burner can be recycled and utilized, further improving the energy utilization rate of the entire system, improving the energy efficiency of the entire system, and saving energy and protecting the environment. By setting up a gas preheater, the gas is heated in the gas preheater, and the heated high-temperature gas enters the burner for auxiliary combustion, which can further utilize the waste heat of the flue gas discharged from the combustion furnace, thereby further improving the energy utilization rate of the entire system and improving the energy efficiency of the entire system. By setting up a superheater and a reheater, the superheater is used to heat the steam from the steam drum to the steam main pipe, and the reheater is used to re-superheat the steam from the reheat steam return pipe to the reheat steam outlet pipe, thereby increasing the pressure and temperature parameters of the steam, thereby improving the overall power generation efficiency of the power plant. By setting up a feed water preheater to preheat the water supplied to the steam drum, the water temperature of the water entering the steam drum can be increased, making the water in the steam drum easier to evaporate, thereby improving the efficiency of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the utility model.

[0022] Description of reference numerals:

[0023] 1. Molten salt heating furnace, 101. High-pressure feed water main, 102. Deaerated water supply pipe, 103. Deaerated water return pipe, 104. Blower pipe, 105. Gas main, 106. Flue gas outlet pipe, 107. Reheat steam outlet pipe, 108. Reheat steam return pipe, 109. Steam main, 2. Waste heat exchanger, 3. Air preheater, 4. Gas preheater, 5. Low-pressure water regulating valve group, 6. High-pressure water regulating valve group, 7. Voltage stabilizer, 8. Low-temperature storage tank, 9. High-temperature storage tank, 10. Feed water preheater, 11. Evaporator, 12. Steam drum, 13. Superheater, 14. Reheater, 15. Bypass valve, 16. First check valve, 17. Second check valve, 18. Third check valve, 19. Burner, 20. Low-temperature pump, 21. High-temperature pump. DETAILED DESCRIPTION

[0024] The following is combined with Figure 1 , the specific implementation of the utility model is described in detail, but it should be understood that the protection scope of the utility model is not limited by the specific implementation. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0025] like Figure 1 As shown, the utility model provides a high-temperature heat storage peak-shaving operation system for low-calorific value coal gas power generation, including a heating furnace heat storage unit and a high-temperature evaporation unit. The heating furnace heat storage unit includes a molten salt heating furnace 1 and a low-temperature storage tank 8. The molten salt heating furnace 1 is connected to the gas main 105 of the original coal gas power generation system. The molten salt heating furnace 1 is used to heat the low-temperature molten salt inside it by using the heat generated after the low-calorific value coal gas is burned. The low-temperature storage tank 8 is used to store the low-temperature molten salt, and the low-temperature storage tank 8 is connected to the molten salt heating furnace 1; the high-temperature evaporation unit includes a high-temperature storage tank 9, an evaporator 11 and a steam drum 12. The high-temperature storage tank 9 is connected to the molten salt heating furnace 1 for storing high-temperature molten salt, the working fluid inlet end of the evaporator 11 is connected to the high-temperature storage tank 9, and the working fluid outlet end of the evaporator 11 is connected to the low-temperature storage tank 8. The steam drum 12 is connected to the evaporator 11 for generating high-temperature saturated steam, and the steam drum 12 is connected to the steam main 109 of the original coal gas power generation system.

[0026] The working principle of the above embodiment is briefly described:

[0027] Molten salt energy storage technology is a technology that uses high-temperature molten salt as a medium, uses energy storage equipment to convert excess electrical energy into thermal energy, and then stores the thermal energy. When needed, the thermal energy is converted into electrical energy and supplied to the power grid. Molten salt energy storage technology mainly includes two links: energy storage link and energy release link. In the energy storage link, electrical energy is converted into thermal energy through electrothermal conversion equipment, and the thermal energy is transferred to molten salt for storage; in the energy release link, molten salt converts the stored thermal energy into electrical energy through thermal energy conversion equipment and supplies it to the power grid.

[0028] The molten salt heating furnace 1 is connected to a low temperature pump 20, which is connected to a low temperature storage tank 8, and the high temperature storage tank 9 is connected to a high temperature pump 21, and the evaporator 11 is connected to the high temperature pump 21. With the operation of the power plant, a large amount of low calorific value coal gas is generated, and the low calorific value coal gas is transported into the burner 19 through the gas main 105, and burns in the burner 19. The low temperature pump 20 transports the low temperature molten salt in the low temperature storage tank 8 into the burner 19, and after being heated by the burner 19, a high temperature molten salt is generated, and the high temperature molten salt enters the high temperature storage tank 9 for storage and standby. During the peak period of electricity consumption, the high temperature molten salt is pumped into the evaporator 11 by the high temperature pump 21 to heat the water in the drum 12. After the water in the drum 12 is heated, high temperature steam is generated, and the high temperature steam enters the steam main 109 of the raw gas power generation system of the power plant to drive the steam generator of the power plant to generate electricity. Through the above scheme, the low calorific value coal gas generated during the operation of the power plant can be recycled and utilized, and during the peak period of electricity consumption, the heat generated by the combustion of the low calorific value coal gas can be used to heat water to generate steam, which is then transported into the steam main 109 of the original coal gas power generation system of the power plant for auxiliary power generation, thereby adjusting the power generation capacity of the power plant and improving the stability of the power grid load.

[0029] The high-temperature heat storage peak-shaving operation system of low-calorific value coal gas power generation of the utility model can be deeply coupled with the original coal gas power generation system, and can adapt the low-calorific value coal gas used in the operation of the power plant to the "peak shaving and valley filling" mode of the power grid, and perform auxiliary power generation during the peak power consumption period, adjust the power generation power of the power plant, improve the stability of the grid load, and increase the economic efficiency of the low-calorific value coal gas power plant. It is a load-side energy storage operation mode for the construction of a new energy system in the country. And the high-temperature heat storage peak-shaving operation system of low-calorific value coal gas power generation of the utility model is generally applicable to the by-product low-calorific value coal gas and power generation operation system in process industrial production. The method of adding a high-temperature heat storage system unit to realize peak-shaving operation is in line with the direction of national new energy construction (encouraging power peak shaving and valley filling), and can also tap the economic value of the by-product low-calorific value coal gas in the industrial process, and has good technical and economic value. The heating furnace heat storage unit is deeply coupled with the original coal gas power generation system, and some public auxiliary facilities are shared. Compared with a simple high-temperature heat storage power generation system (such as a solar thermal power generation system), it reduces the land occupation and investment amount, and the operating personnel do not need to be increased, reducing the operating cost. The system can be set up with a variety of operating modes, and can operate synchronously or load-staggered with the original gas power generation system, so that the gas power generation can vary with the peak and valley electricity prices of the power grid, thus achieving economic benefits.

[0030] On the basis of the above-mentioned embodiment, in order to utilize the waste heat of flue gas generated by the burner 19, the energy utilization rate of the whole system is improved, the energy efficiency of the whole system is improved, and energy saving and environmental protection are achieved.

[0031] like Figure 1 As shown, the molten salt heating furnace 1 is equipped with a burner 19, and the burner 19 is connected to the gas main 105. The burner 19 is connected to the waste heat exchanger 2 through the molten salt heating furnace 1. The water inlet of the waste heat exchanger 2 is connected to the deoxygenated water supply pipe 102 of the original gas power generation system, and the water outlet of the waste heat exchanger 2 is connected to the deoxygenated water return pipe 103 of the original gas power generation system. The waste heat exchanger 2 is used to utilize the waste heat of the flue gas discharged by the burner 19 to heat the deoxygenated water.

[0032] The high-temperature flue gas discharged from the burner 19 passes through the molten salt heating furnace 1 and then enters the waste heat exchanger 2 to heat the deoxygenated water flowing in from the deoxygenated water supply pipe 102, and then flows out from the deoxygenated water return pipe 103 to be used by the steam boiler of the generator, thereby utilizing the waste heat of the flue gas generated by the burner 19, thereby improving the energy utilization rate of the entire system, improving the energy efficiency of the entire system, and saving energy and protecting the environment.

[0033] On the basis of the above embodiments, in order to further improve the energy utilization rate of the entire system, the energy efficiency of the entire system is improved.

[0034] like Figure 1As shown, the air inlet of the waste heat exchanger 2 is connected to the burner 19, the air outlet of the waste heat exchanger 2 is connected to the air preheater 3, the air inlet of the air preheater 3 is connected to the blower pipe 104 of the original gas power generation system, and the air outlet of the air preheater 3 is connected to the air inlet of the burner 19. The air preheater 3 is used to utilize the waste heat of the flue gas discharged from the waste heat exchanger 2 to heat the air entering the burner 19.

[0035] The high-temperature flue gas discharged from the waste heat exchanger 2 enters the air preheater 3, and heats the air entering from the blower pipe 104, thereby increasing the temperature of the air entering the burner 19, thereby recycling the waste heat of the flue gas generated by the burner 19, further improving the energy utilization rate of the entire system, improving the energy efficiency of the entire system, and saving energy and protecting the environment.

[0036] As a preferred solution, Figure 1 As shown, the air preheater 3 includes a first air supply port, a second air supply port, a first exhaust port and a second exhaust port, the first air supply port is connected to the blower pipe 104, the first exhaust port is connected to the first air supply port, the first exhaust port is connected to the air inlet of the burner 19, the second air supply port is connected to the air outlet of the waste heat exchanger 2, the second air supply port is connected to the second exhaust port, the second exhaust port is connected to a gas preheater 4, the gas preheater 4 is connected to the flue gas outlet pipe 106 of the original gas power generation system, the air inlet of the gas preheater 4 is connected to the gas main 105 of the original gas power generation system, the air outlet of the gas preheater 4 is connected to the air inlet of the burner 19, and the gas preheater 4 is used to utilize the waste heat of the flue gas discharged from the air preheater 3 to heat the gas entering the burner 19. The high-temperature flue gas discharged from the outlet of the waste heat exchanger 2 enters the air preheater 3 through the second air supply port to heat the air preheater 3, and then enters the gas preheater 4 through the second exhaust port to heat the gas preheater 4. The blower connecting pipe 104 passes air into the air preheater 3 through the first air supply port. After the air is heated in the air preheater 3, it enters the burner 19 through the first exhaust port. The gas main pipe 105 passes gas into the gas preheater 4. The gas is heated in the gas preheater 4. The heated high-temperature gas enters the burner 19 for auxiliary combustion, which can further utilize the waste heat of the flue gas discharged from the burner 19, thereby further improving the energy utilization rate of the entire system and improving the energy efficiency of the entire system.

[0037] As a preferred solution, Figure 1As shown, a superheater 13 and a reheater 14 are provided between the evaporator 11 and the high-temperature storage tank 9, the inlets of the superheater 13 and the reheater 14 are both connected to the high-temperature storage tank 9, the outlets of the superheater 13 and the reheater 14 are both connected to the evaporator 11, the air inlet of the superheater 13 is connected to the steam drum 12, the air outlet of the superheater 13 is connected to the steam main 109, the superheater 13 is used to heat the steam from the steam drum 12 to the steam main 109, the air inlet of the reheater 14 is connected to the reheat steam return pipe 108 of the original gas power generation system, the air outlet of the reheater 14 is connected to the reheat steam outlet pipe 107 of the original gas power generation system, and the reheater 14 is used to heat the steam from the reheat steam return pipe 108 to the reheat steam outlet pipe 107. By providing a superheater 13 and a reheater 14, the superheater 13 is used to heat the steam from the steam drum 12 to the steam main 109, and the reheater 14 is used to superheat the steam from the reheat steam return pipe 108 to the reheat steam outlet pipe 107 again, thereby increasing the pressure and temperature parameters of the steam, thereby improving the overall power generation efficiency of the power plant.

[0038] As a preferred solution, Figure 1 As shown, a first one-way valve 16 is provided between the gas outlet of the superheater 13 and the steam main pipe 109, and the first one-way valve 16 is used for one-way communication from the gas outlet of the superheater 13 to the steam main pipe 109, a second one-way valve 17 is provided between the gas inlet of the reheater 14 and the reheated steam return pipe 108, and the second one-way valve 17 is used for one-way communication from the reheated steam return pipe 108 to the gas inlet of the reheater 14, and a third one-way valve 18 is provided between the gas outlet of the reheater 14 and the reheated steam outlet pipe 107, and the third one-way valve 18 is used for one-way communication from the gas outlet of the reheater 14 to the reheated steam outlet pipe 107. By providing the first one-way valve 16, the steam heated by the superheater 13 can be one-way communicated from the superheater 13 to the steam main pipe 109, and the steam backflow in the steam main pipe 109 is prevented, thereby ensuring the normal operation of the entire system. Similarly, the second one-way valve 17 can prevent the steam from flowing back in the reheater 14, and the third one-way valve 18 can prevent the steam from flowing back in the reheat steam outlet pipe 107, thereby ensuring the normal operation of the entire system.

[0039] As a preferred solution, Figure 1As shown, a feedwater preheater 10 is provided between the evaporator 11 and the low-temperature storage tank 8, the inlet of the feedwater preheater 10 is connected to the evaporator 11, the outlet of the feedwater preheater 10 is connected to the low-temperature storage tank 8, the water inlet of the feedwater preheater 10 is connected to the high-pressure water supply main 101 of the original gas power generation system, and the water outlet of the feedwater preheater 10 is connected to the steam drum 12, and the feedwater preheater 10 is used to heat the water entering the steam drum 12. By providing the feedwater preheater 10, the water supplied to the steam drum 12 is preheated, the water temperature of the water entering the steam drum 12 can be increased, and the water in the steam drum 12 is more easily evaporated, thereby improving the efficiency of the entire system.

[0040] As a preferred solution, Figure 1 As shown, the waste heat exchanger 2 is connected in parallel with a bypass valve 15, one end of the bypass valve 15 is communicated with the air inlet of the waste heat exchanger 2, and the other end of the bypass valve 15 is communicated with the air outlet of the waste heat exchanger 2. By setting the bypass valve 15, the amount of flue gas entering the waste heat exchanger 2 is adjusted through the bypass valve 15, so that the heating speed of the deoxygenated water can be adjusted according to the water supply speed of the deoxygenated water supply pipe 102.

[0041] As a preferred solution, Figure 1 As shown, a low-pressure water regulating valve group 5 is provided between the water inlet of the waste heat exchanger 2 and the deoxygenated water supply pipe 102, and a pressure stabilizing detector 7 is provided between the water outlet of the waste heat exchanger 2 and the deoxygenated water return pipe 103. By providing the low-pressure water regulating valve group 5, the supply speed of the deoxygenated water can be adjusted, and by providing the pressure stabilizing detector 7, the water pressure flowing from the waste heat exchanger 2 to the deoxygenated water return pipe 103 can be adjusted, thereby ensuring the water pressure of the deoxygenated water return pipe 103 is stable.

[0042] As a preferred solution, Figure 1 As shown, a high-pressure water regulating valve group 6 is provided between the water inlet of the feed water preheater 10 and the high-pressure water supply main pipe 101. By providing the high-pressure water regulating valve group 6, the water flow rate flowing to the feed water preheater 10 can be adjusted.

[0043] Molten salt energy storage technology is an emerging energy storage technology. By using molten salt as an energy storage medium, it can effectively solve the problems of large volatility and instability of renewable energy, providing a feasible solution for energy transformation.

[0044] Molten salt energy storage technology is a technology that uses high-temperature molten salt as a medium, uses energy storage equipment to convert excess electrical energy into thermal energy, and then stores the thermal energy. When needed, the thermal energy is converted into electrical energy and supplied to the power grid. Molten salt energy storage technology mainly includes two links: energy storage link and energy release link. In the energy storage link, electrical energy is converted into thermal energy through electrothermal conversion equipment, and the thermal energy is transferred to molten salt for storage; in the energy release link, molten salt converts the stored thermal energy into electrical energy through thermal energy conversion equipment and supplies it to the power grid.

[0045] Molten salt energy storage technology has a wide range of applications. First, it can be used for peak-shaving and valley-filling of power grids to solve the problem of intermittent power generation of renewable energy. Since the power generation of renewable energy (such as wind energy and solar energy) is unstable, molten salt energy storage technology can store excess electricity and release it when needed to balance the supply and demand of electricity and improve the stability of the power grid. Secondly, molten salt energy storage technology can also be used for energy recovery in industrial production processes. Many industrial production processes generate a lot of waste heat. Through molten salt energy storage technology, this waste heat can be stored and converted into electricity to improve energy utilization efficiency. In addition, molten salt energy storage technology can also be used for energy management of buildings, and by storing solar energy or waste heat, building energy self-sufficiency can be achieved.

[0046] Molten salt energy storage technology has many advantages over traditional energy storage technology. First, as an energy storage medium, molten salt has high heat capacity and thermal conductivity, which can achieve efficient energy conversion and storage. Secondly, the molten salt energy storage system has a long life and can operate continuously for many years without being limited by the number of charge and discharge cycles. In addition, molten salt energy storage technology can achieve large-scale energy storage capacity to meet the needs of different application scenarios. Most importantly, molten salt energy storage technology is a clean energy storage technology that is environmentally friendly and does not produce pollutants and greenhouse gases.

[0047] Although molten salt energy storage technology has broad application prospects and many advantages, it also faces some challenges. First, the construction cost of molten salt energy storage technology is high and requires a lot of investment. Secondly, the operation and maintenance costs of the molten salt energy storage system are also high, requiring professional technicians to manage and maintain it. In addition, the safety of molten salt energy storage technology is also an issue that needs to be taken seriously, and effective measures need to be taken to ensure the safe and stable operation of the system.

[0048] Molten salt energy storage technology is an energy storage technology with great potential. It can effectively solve the problem of large volatility and instability of renewable energy. It has broad application prospects in the fields of power grid peak shifting, industrial energy recovery and building energy management. Although molten salt energy storage technology faces some challenges, with the continuous development of technology and the reduction of costs, it is believed that molten salt energy storage technology will become an important technology in the field of energy storage in the future.

[0049] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-temperature heat storage peak-shaving operation system for low calorific value gas power generation, characterized in that: include: A heating furnace heat storage unit, comprising a molten salt heating furnace (1) and a low-temperature storage tank (8), wherein the molten salt heating furnace (1) is connected to a gas main (105) of an existing gas power generation system, the molten salt heating furnace (1) is used to heat the low-temperature molten salt therein by utilizing the heat generated by the combustion of low-calorific value gas, and the low-temperature storage tank (8) is used to store the low-temperature molten salt, and the low-temperature storage tank (8) is connected to the molten salt heating furnace (1); A high-temperature evaporation unit comprises a high-temperature storage tank (9), an evaporator (11) and a steam drum (12); the high-temperature storage tank (9) is connected to the molten salt heating furnace (1) and is used to store high-temperature molten salt; the working fluid inlet end of the evaporator (11) is connected to the high-temperature storage tank (9); the working fluid outlet end of the evaporator (11) is connected to the low-temperature storage tank (8); the steam drum (12) is connected to the evaporator (11) and is used to generate high-temperature saturated steam; the steam drum (12) is connected to a steam main pipe (109) of a raw coal gas power generation system.

2. The high-temperature heat storage peak-shaving operation system for low calorific value coal gas power generation according to claim 1, characterized in that: The molten salt heating furnace (1) is equipped with a burner (19), the burner (19) is connected to the gas main (105), the burner (19) is connected to a waste heat exchanger (2) through the molten salt heating furnace (1), the water inlet of the waste heat exchanger (2) is connected to a deoxygenated water supply pipe (102) of an original gas power generation system, and the water outlet of the waste heat exchanger (2) is connected to a deoxygenated water return pipe (103) of the original gas power generation system. The waste heat exchanger (2) is used to utilize the waste heat of the flue gas discharged by the burner (19) to heat the deoxygenated water.

3. The high-temperature heat storage peak-shaving operation system for low calorific value coal gas power generation according to claim 2, characterized in that: The air inlet of the waste heat exchanger (2) is connected to the burner (19), and the air outlet of the waste heat exchanger (2) is connected to the air preheater (3). The air inlet of the air preheater (3) is connected to the blower pipe (104) of the original gas power generation system, and the air outlet of the air preheater (3) is connected to the air inlet of the burner (19). The air preheater (3) is used to utilize the waste heat of the flue gas discharged from the waste heat exchanger (2) to heat the air entering the burner (19).

4. The high-temperature heat storage peak-shaving operation system for low calorific value coal gas power generation according to claim 3, characterized in that: The air preheater (3) comprises a first air supply port, a second air supply port, a first exhaust port and a second exhaust port, wherein the first air supply port is connected to the blower pipe (104), the first exhaust port is connected to the air inlet of the burner (19), the second air supply port is connected to the air outlet of the waste heat exchanger (2), the second exhaust port is connected to a gas preheater (4), the gas preheater (4) is connected to the flue gas outlet pipe (106) of the original gas power generation system, the air inlet of the gas preheater (4) is connected to the gas main pipe (105) of the original gas power generation system, the air outlet of the gas preheater (4) is connected to the air inlet of the burner (19), and the gas preheater (4) is used to utilize the waste heat of the flue gas discharged from the air preheater (3) to heat the gas entering the burner (19).

5. The high-temperature heat storage peak-shaving operation system for low calorific value coal gas power generation according to claim 1, characterized in that: A superheater (13) and a reheater (14) are provided between the evaporator (11) and the high-temperature storage tank (9); the inlets of the superheater (13) and the reheater (14) are both connected to the high-temperature storage tank (9); the outlets of the superheater (13) and the reheater (14) are both connected to the evaporator (11); the air inlet of the superheater (13) is connected to the steam drum (12); and the air outlet of the superheater (13) is connected to the steam main pipe (109). The superheater (13) is used to heat the steam from the steam drum (12) to the steam main (109); the air inlet of the reheater (14) is connected to the reheat steam return pipe (108) of the original coal gas power generation system; the air outlet of the reheater (14) is connected to the reheat steam outlet pipe (107) of the original coal gas power generation system; the reheater (14) is used to heat the steam from the reheat steam return pipe (108) to the reheat steam outlet pipe (107).

6. The high-temperature heat storage peak-shaving operation system for low calorific value coal gas power generation according to claim 5, characterized in that: A first non-return valve (16) is provided between the gas outlet of the superheater (13) and the steam main pipe (109), and the first non-return valve (16) is used for one-way communication from the gas outlet of the superheater (13) to the steam main pipe (109). A second non-return valve (17) is provided between the gas inlet of the reheater (14) and the reheated steam return pipe (108), and the second non-return valve (17) is used for one-way communication from the reheated steam return pipe (108) to the gas inlet of the reheater (14). A third non-return valve (18) is provided between the gas outlet of the reheater (14) and the reheated steam outlet pipe (107), and the third non-return valve (18) is used for one-way communication from the gas outlet of the reheater (14) to the reheated steam outlet pipe (107).

7. The high-temperature heat storage peak-shaving operation system for low calorific value coal gas power generation according to claim 1, characterized in that: A feed water preheater (10) is provided between the evaporator (11) and the low-temperature storage tank (8); the inlet of the feed water preheater (10) is connected to the evaporator (11); the outlet of the feed water preheater (10) is connected to the low-temperature storage tank (8); the water inlet of the feed water preheater (10) is connected to the high-pressure feed water main (101) of the original gas power generation system; the water outlet of the feed water preheater (10) is connected to the steam drum (12); the feed water preheater (10) is used to heat water entering the steam drum (12).

8. The high-temperature heat storage peak-shaving operation system for low calorific value coal gas power generation according to claim 2, characterized in that: The waste heat exchanger (2) is connected in parallel with a bypass valve (15), one end of the bypass valve (15) is connected to the air inlet of the waste heat exchanger (2), and the other end of the bypass valve (15) is connected to the air outlet of the waste heat exchanger (2).

9. The high-temperature heat storage peak-shaving operation system for low calorific value coal gas power generation according to claim 2, characterized in that: A low-pressure water regulating valve group (5) is provided between the water inlet of the waste heat exchanger (2) and the deoxygenated water supply pipe (102), and a pressure stabilizing detector (7) is provided between the water outlet of the waste heat exchanger (2) and the deoxygenated water return pipe (103).

10. The high-temperature heat storage peak-shaving operation system for low calorific value coal gas power generation according to claim 7, characterized in that: A high-pressure water regulating valve group (6) is provided between the water inlet of the feed water preheater (10) and the high-pressure feed water main pipe (101).

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