Fused salt energy storage coupled dry quenching and photovoltaic power generation cooperative energy supply system

Abstract

The utility model relates to the technical field of comprehensive energy, and provides a fused salt energy storage coupled dry quenching and photovoltaic power generation collaborative energy supply system. The system comprises a dry quenching waste heat power generation unit which comprises a dry quenching waste heat boiler, an inert gas circulation system and a steam turbine power generation set, and the inert gas circulation system is connected with the steam turbine power generation set through the dry quenching waste heat boiler; the fused salt energy storage unit comprises a low-pressure waste heat boiler, the low-pressure waste heat boiler is connected with a fused salt heat exchanger, an inert gas circulation system and a steam turbine power generation set, and the fused salt heat exchanger is connected with the inert gas circulation system. A fused salt heat exchanger, a hot fused salt tank, an SGS steam generator, a cold fused salt tank and a fused salt electric heater which are connected through pipelines are sequentially arranged in the liquid-gas flowing direction, the cold fused salt tank is connected with the fused salt heat exchanger, and the fused salt electric heater is connected with the hot fused salt tank. And the new energy power generation unit is used for supplying power to the fused salt electric heater.

Description

Technical Field

[0001] This utility model relates to the field of integrated energy technology, and in particular to a synergistic energy supply system that couples molten salt energy storage with dry quenching and photovoltaic power generation. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] Currently, dry quenching is the most common method used in coke production, and waste heat boilers and power generation units are built to recover the heat from the red-hot coke for power generation or to supply steam to enterprises and industrial parks. To achieve green and low-carbon transformation and development and reduce production costs, some enterprises have built photovoltaic power generation projects. In actual production, the energy supply systems of high-energy-consuming enterprises such as coking and steel face three challenges: 1) Energy supply is volatile, such as the waste heat from dry quenching fluctuating with the production rhythm of coke ovens, resulting in low utilization rates at night; photovoltaic power generation is greatly affected by weather and is mismatched with industrial load demand; 2) Photovoltaic power generation using traditional electrochemical methods faces energy storage bottlenecks, with high storage costs and short lifespans, making it difficult to support large-scale industrial peak-shaving needs; 3) There is insufficient coordination among various energy sources, such as the independent operation of waste heat power generation, photovoltaic and energy storage systems, lacking multi-energy complementarity strategies, resulting in low overall energy efficiency.

[0004] With the large-scale integration of clean, efficient, safe, and low-carbon energy systems such as wind and solar power into the power grid, high-energy-consuming enterprises such as steel and coking are required to actively respond to peak-shaving demands and reduce the pressure on the power grid for peak shaving. Utility Model Content

[0005] To address the issues of low efficiency, high energy storage costs, and insufficient functional stability in existing coking plant systems that combine waste heat with renewable energy, this invention provides a synergistic energy supply system that couples molten salt energy storage with dry quenching waste heat power generation and photovoltaic power generation. By coupling molten salt energy storage with waste heat power generation from dry quenching and photovoltaic power generation, this invention breaks down the barriers to independent operation of photovoltaic power generation, waste heat from dry quenching, and energy storage, achieving energy coupling and cascade utilization, and realizing comprehensive utilization of waste heat.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of this utility model provides a synergistic energy supply system that couples molten salt energy storage with dry quenching and photovoltaic power generation.

[0008] A synergistic energy supply system coupling molten salt energy storage with dry quenching and photovoltaic power generation includes:

[0009] The dry quenching waste heat power generation unit includes a dry quenching waste heat boiler, an inert gas circulation system, and a steam turbine power generation unit. The inert gas circulation system is connected to the steam turbine power generation unit through the dry quenching waste heat boiler.

[0010] The molten salt energy storage unit includes a low-pressure waste heat boiler, which is connected to a molten salt heat exchanger, an inert gas circulation system, and a steam turbine generator set. The molten salt heat exchanger is connected to the inert gas circulation system. In the direction of liquid-gas flow, the unit is provided with a molten salt heat exchanger, a hot molten salt tank, an SGS steam generator, a cold molten salt tank, and a molten salt electric heater connected by pipelines. The cold molten salt tank is connected to the molten salt heat exchanger, and the molten salt electric heater is connected to the hot molten salt tank.

[0011] The new energy power generation unit is used to supply power to the molten salt electric heater.

[0012] Furthermore, the inert gas circulation system includes a dry quenching furnace, a primary dust collector, and a secondary dust collector connected sequentially by pipelines in the direction of gas flow. The secondary dust collector is connected to the dry quenching furnace via a circulating fan.

[0013] Furthermore, the primary dust collector is connected to the first air inlet of the dry quenching waste heat boiler, and the first air outlet of the dry quenching waste heat boiler is connected to the secondary dust collector and the low-pressure waste heat boiler. A low-temperature inert gas bypass valve is provided on the pipeline between the low-pressure waste heat boiler and the secondary dust collector.

[0014] Furthermore, a high-temperature inert gas bypass valve is provided on the pipeline between the molten salt heat exchanger and the primary dust collector.

[0015] Furthermore, the steam turbine generator set includes a steam turbine, a generator, an air-cooled island, and a deaerator. The second outlet of the dry quenching waste heat boiler is connected to the steam turbine. The steam turbine is connected to both the generator and the air-cooled island. A condensate pump is installed on the pipeline between the air-cooled island and the deaerator. A boiler feed water pump is installed on the pipeline between the deaerator and the second inlet of the dry quenching waste heat boiler.

[0016] Furthermore, the low-pressure waste heat boiler is provided with a first demineralized water inlet pipe and a first low-pressure steam outlet pipe. A first low-pressure steam switching valve is provided on the first low-pressure steam outlet pipe. The first low-pressure steam outlet pipe is connected to the pipe entering the steam turbine, and a second low-pressure steam switching valve is provided on the pipe entering the steam turbine.

[0017] Furthermore, the SGS steam generator is equipped with a second demineralized water inlet pipe and a second low-pressure steam outlet pipe. The second low-pressure steam outlet pipe is connected to the pipe between the second steam outlet of the dry quenching waste heat boiler and the steam turbine.

[0018] Furthermore, the hot molten salt tank is equipped with a hot molten salt pump at its outlet end, and the cold molten salt tank is equipped with a cold molten salt pump at its outlet end.

[0019] Furthermore, the new energy power generation unit includes a photovoltaic power generation unit or a wind power generation unit.

[0020] Compared with the prior art, the beneficial effects of this utility model are:

[0021] (1) This utility model combines molten salt energy storage with dry quenching waste heat power generation and photovoltaic power generation, breaking the barrier of independent operation of photovoltaic power generation, dry quenching waste heat and energy storage, realizing energy coupling and cascade utilization, achieving a waste heat comprehensive utilization rate that is more than 15% higher than the traditional mode, reducing the photovoltaic curtailment rate from the industry average of 10% to below 5%, and achieving a consumption rate of over 95%.

[0022] (2) This utility model uses molten salt energy storage to replace electrochemical energy storage, which reduces the cost of industrial peak-shaving electricity by more than 40%, shortens the equipment investment payback period to less than 5 years, and the service life of the molten salt energy storage system is more than 25 years, which is about 10 years longer than that of electrochemical energy storage.

[0023] (4) This utility model provides a full-chain solution for industries such as coking and steel, namely “waste heat recovery - low-cost energy storage - stable energy supply”, to accelerate the low-carbon transformation of the industrial sector. Attached Figure Description

[0024] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0025] Figure 1 This is a structural diagram of a synergistic energy supply system for molten salt energy storage coupled with dry quenching and photovoltaic power generation, as shown in an embodiment of this utility model.

[0026] Among them, 1. Dry quenching furnace, 2. Primary dust collector, 3. High-temperature inert gas bypass valve, 4. Low-pressure waste heat boiler, 5. Molten salt heat exchanger, 6. Photovoltaic power generation unit, 7. Hot molten salt pump, 8. Hot molten salt tank, 9. SGS steam generator, 10. Cold molten salt tank, 11. Cold molten salt pump, 12. Molten salt electric heater, 13. First low-pressure steam switching valve, 14. Second low-pressure steam switching valve, 15. Steam turbine, 16. Generator, 17. Air-cooled island, 18. Condensate pump, 19. Deaerator, 20. Boiler feed water pump, 21. Dry quenching coke waste heat boiler, 22. Low-temperature inert gas bypass valve, 23. Secondary dust collector, 24. Circulating fan. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0029] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0030] Example 1

[0031] like Figure 1 As shown, this embodiment provides a synergistic energy supply system that couples molten salt energy storage with dry quenching and photovoltaic power generation, including:

[0032] The dry quenching waste heat power generation unit includes a dry quenching waste heat boiler 21, an inert gas circulation system, and a steam turbine power generation unit. The inert gas circulation system is connected to the steam turbine power generation unit through the dry quenching waste heat boiler 21.

[0033] The molten salt energy storage unit includes a low-pressure waste heat boiler 4, which is connected to a molten salt heat exchanger 5, an inert gas circulation system, and a steam turbine generator set. The molten salt heat exchanger 5 is connected to the inert gas circulation system. In the direction of liquid-gas flow, the molten salt heat exchanger 5, a hot molten salt tank 8, an SGS steam generator 9, a cold molten salt tank 10, and a molten salt electric heater 12 are connected by pipelines. The cold molten salt tank 10 is connected to the molten salt heat exchanger 5, and the molten salt electric heater 12 is connected to the hot molten salt tank 8.

[0034] The new energy power generation unit is connected to the molten salt electric heater 12 and is used to supply power to the molten salt electric heater 12.

[0035] In some possible implementations, the inert gas circulation system includes a dry quenching furnace 1, a primary dust collector 2, and a secondary dust collector 23 connected in sequence by pipelines in the direction of gas flow. The secondary dust collector 23 is connected to the dry quenching furnace 1 via a circulating fan 24.

[0036] In some possible implementations, the primary dust collector 2 is connected to the first air inlet of the dry quenching waste heat boiler 21, the first air outlet of the dry quenching waste heat boiler 21 is connected to the secondary dust collector 23 and the low-pressure waste heat boiler 4, and a low-temperature inert gas bypass valve 22 is provided on the pipeline between the low-pressure waste heat boiler 4 and the secondary dust collector 23.

[0037] In some possible implementations, a high-temperature inert gas bypass valve 3 is provided on the pipeline between the molten salt heat exchanger 5 and the primary dust collector 2.

[0038] In this embodiment, the high-temperature inert gas bypass valve 3 is connected to the high-temperature gas pipeline after the primary dust collector 2, and the low-temperature inert gas bypass valve 22 is connected to the low-temperature gas pipeline after the secondary dust collector 23. The molten salt heat exchanger 5 and the low-pressure waste heat boiler 4 are connected to the high-temperature inert gas bypass valve 3 and the low-temperature inert gas bypass valve 22 through gas pipelines.

[0039] In some possible implementations, the steam turbine generator set includes a steam turbine 15, a generator 16, an air-cooled island 17, and a deaerator 19. The second outlet of the dry quenching waste heat boiler 21 is connected to the steam turbine 15. The steam turbine 15 is connected to the generator 16 and the air-cooled island 17. A condensate pump 18 is installed on the pipeline between the air-cooled island 17 and the deaerator 19. A boiler feed water pump 20 is installed on the pipeline between the deaerator 19 and the second inlet of the dry quenching waste heat boiler 21.

[0040] In some possible implementations, the low-pressure waste heat boiler 4 is provided with a first demineralized water inlet pipe and a first low-pressure steam outlet pipe. A first low-pressure steam switching valve 13 is provided on the first low-pressure steam outlet pipe. The first low-pressure steam outlet pipe is connected to the pipe entering the steam turbine 15, and a second low-pressure steam switching valve 14 is provided on the pipe entering the steam turbine 15.

[0041] In this embodiment, the low-pressure waste heat boiler 4 solves the problem of high inert gas temperature at the outlet of the molten salt heat exchanger 5. This system uses binary molten salt, with a molten salt operating temperature of 290–565°C. Therefore, the inert gas temperature of the molten salt heat exchanger is not lower than 290°C. The existing boiler's low-temperature section lacks docking space for this flue gas, and its connection to the inert gas outlet of the dry quenching waste heat boiler would result in a high inlet gas temperature for the dry quenching furnace, affecting coke cooling. Therefore, this low-pressure waste heat boiler generates saturated steam for chemical production and other processes, avoiding energy waste caused by the desuperheating and pressure reduction required when the turbine 15 extracts superheated steam, thus improving energy utilization.

[0042] In this embodiment, the steam turbine 15 is provided with a low-pressure steam supply pipeline, and a second low-pressure steam switching valve 14 is installed on the pipeline. The low-pressure steam is used for the coking production process.

[0043] In some possible implementations, the SGS steam generator 9 is provided with a second demineralized water inlet pipe and a second low-pressure steam outlet pipe, the second low-pressure steam outlet pipe being connected to the pipe between the second steam outlet of the dry quenching waste heat boiler 21 and the steam turbine 15.

[0044] In this embodiment, the SGS steam generator 9 can generate high-pressure steam for the steam turbine to generate electricity, and the SGS steam generator 9 can also generate low-pressure steam for direct production use.

[0045] In some possible implementations, the outlet end of the hot molten salt tank 8 is provided with a hot molten salt pump 7, and the outlet end of the cold molten salt tank 10 is provided with a cold molten salt pump 11.

[0046] In this embodiment, the cold molten salt tank 10 is equipped with a cold molten salt pump 11. The outlet of the cold molten salt pump 11 is connected to the molten salt heat exchanger 5 and the molten salt electric heater 12 via pipes. The molten salt heat exchanger 5 and the molten salt electric heater 12 are connected to the hot molten salt tank 8 via pipes. The hot molten salt tank 8 is equipped with a hot molten salt pump 7. The outlet of the hot molten salt pump 7 is connected to the SGS steam generator 9 via pipes. The molten salt outlet of the SGS steam generator 9 is connected to the cold molten salt tank 10.

[0047] In some possible implementations, the new energy power generation unit includes renewable resource power generation such as photovoltaic power generation unit 6 or wind power generation unit.

[0048] In this embodiment, the photovoltaic power generation unit 6 includes: a photovoltaic panel array, an inverter, and grid connection equipment, etc.

[0049] The specific implementation method is as follows:

[0050] During off-peak electricity pricing periods or when photovoltaic power curtailment occurs, molten salt is heated and stored in a hot molten salt tank 8 using photovoltaic power through a molten salt electric heater 12, thereby reducing grid-connected electricity or preventing photovoltaic power curtailment.

[0051] During off-peak electricity hours, a portion of the high-temperature inert gas is introduced into the molten salt heat exchanger 5 and the low-pressure waste heat boiler 4 via a high-temperature inert gas bypass valve 3. The 900°C high-temperature inert gas exchanges heat with the approximately 290°C low-temperature molten salt in the molten salt heat exchanger 5. The high-temperature inert gas then initially cools to 350°C, while the low-temperature molten salt is heated to 600°C. The initially cooled 350°C high-temperature inert gas then enters the low-pressure waste heat boiler 4 to heat the demineralized water. After cooling to approximately 180°C, the inert gas enters the secondary dust collector 23 through a gas pipeline for dust removal, and then enters the dry quenching furnace 1 to cool the coke. The low-pressure waste heat boiler 4 generates approximately 0.78MPa of low-pressure saturated steam for use in chemical and other production processes. At this time, the dry quenching coke waste heat boiler 21 reduces the amount of high-temperature inert gas entering the boiler, reducing steam production and power generation, increasing the electricity output from the grid, and simultaneously, the turbine no longer extracts low-pressure steam for production processes.

[0052] During peak electricity pricing periods, the high-temperature molten salt in the hot molten salt tank 8 is pumped by the hot molten salt pump 7 into the SGS steam generator 9 to heat the demineralized water, generating high-temperature, high-pressure steam. This steam is then combined with the steam generated by the dry quenching waste heat boiler 21 and enters the steam turbine 15, increasing the power generation of the steam turbine 15, reducing the amount of electricity generated on the grid, and providing peak shaving services for the grid. By utilizing the peak-valley electricity price difference and the curtailment of photovoltaic power, the company reduces its energy costs and improves its economic efficiency. At this time, the steam turbine needs to extract low-pressure steam to supply the production process.

[0053] The coordinated heating described in this embodiment can supply steam for coking production or provide steam and heating for industrial parks.

[0054] This invention addresses the challenges of large fluctuations in waste heat from dry quenching, intermittent photovoltaic power generation, and high costs of traditional energy storage. The system utilizes a multi-mode "electricity-heat-heat" conversion through molten salt energy storage to achieve cascaded energy utilization: ① Surplus photovoltaic power drives a molten salt electric heater for heat storage; ② A molten salt heat exchanger is added to the flue gas side of the dry quenching waste heat boiler, storing heat energy in a high-temperature molten salt tank during off-peak electricity price periods; ③ During peak electricity price periods, the heat from the molten salt in the hot salt tank is used to generate steam through an SGS steam generator, which then enters a steam turbine to generate electricity, releasing heat. This invention breaks through the bottleneck of single-energy utilization, achieving a waste heat comprehensive utilization rate increase of over 15% and a photovoltaic absorption rate of over 95% in high-energy-consuming scenarios such as coking and steelmaking, while simultaneously reducing energy supply costs by 20%, providing technical support for industrial decarbonization.

[0055] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A molten salt energy storage coupled system for co-supplying energy of dry quenching of coke and photovoltaic power generation, characterized in that, The application relates to a dry quenching waste heat power generation unit, a molten salt energy storage unit and a new energy power generation unit. The inert gas circulation system comprises a dry quenching furnace, a primary dust collector and a secondary dust collector which are sequentially arranged and connected by pipelines according to the flowing direction of the gas. The first gas outlet of the dry quenching waste heat boiler is connected with the secondary dust collector and the low-pressure waste heat boiler. A low-temperature inert gas bypass valve is arranged on the pipeline between the low-pressure waste heat boiler and the secondary dust collector.

2. The molten salt energy storage coupled system of claim 1, wherein, A high-temperature inert gas bypass valve is arranged on the pipeline between the molten salt heat exchanger and the primary dust collector.

3. The molten salt energy storage coupled system of claim 2, wherein, The steam turbine power generation set comprises a steam turbine, a generator, an air cooling island and a deaerator.

4. The molten salt energy storage coupled system of claim 3, wherein, The low-pressure waste heat boiler is provided with a first desalted water inlet pipeline and a first low-pressure steam outlet pipeline.

5. The molten salt energy storage coupled system of claim 2, wherein, The SGS steam generator is provided with a second desalted water inlet pipeline and a second low-pressure steam outlet pipeline.

6. The molten salt energy storage coupled system of claim 1, wherein, The outlet end of the hot molten salt tank is provided with a hot molten salt pump, and the outlet end of the cold molten salt tank is provided with a cold molten salt pump.

7. The molten salt energy storage coupled system of claim 6, wherein, The new energy power generation unit comprises a photovoltaic power generation unit or a wind power generation unit.

8. The molten salt energy storage coupled system of claim 6, wherein, ​ 9. The molten salt energy storage coupled system of claim 1, wherein, ​ 10. The molten salt energy storage coupled system of claim 1, wherein, ​

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