Energy storage system based on natural gas conveying pipe network

Abstract

The invention discloses an energy storage system based on a natural gas conveying pipe network. The energy storage system comprises a natural gas compressor, a waste heat utilization system, a natural gas high-pressure conveying pipeline, a natural gas low-pressure conveying pipeline, a turbine power generation device and a cold energy utilization system. The waste heat utilization system comprises a natural gas cooler, a hot water pool, a heating radiator, a hot water heat exchanger and a cold water pool. The cold energy utilization system comprises a natural gas heater, a cold storage tank, a cold energy utilization device and a secondary refrigerant storage tank; thus, natural gas is compressed and stored, the manufacturing cost of an energy storage system is greatly reduced, meanwhile, the peak regulation capacity of the natural gas is enhanced, and meanwhile the dual advantages of storing the natural gas and energy at night, being used in the daytime and generating electricity can be achieved; the obtained heat energy can be used for supplying heat to users, and recycling of the heat energy is achieved; and secondly, the part of cold energy is recycled and output through the cold energy utilization device to supply cold to users, recycling of the cold energy is achieved, and the total efficiency of energy storage is improved.

Description

Technical Field

[0001] The present invention relates to technologies in the field of natural gas storage and transportation and energy storage, and in particular to an energy storage system based on a natural gas transmission pipeline network. Background Art

[0002] With the continuous adjustment of the heating fuel structure in my country's large cities, natural gas heating has developed rapidly; as an efficient and clean energy source, natural gas has been widely used in recent years; before entering the city gate station or gas power plant, the main natural gas pipeline must be depressurized according to different requirements before it can be used. The natural gas transmission pressure is 6-8MPa, and the industrial gas pressure is about 0.3-3MPa. Before entering the natural gas user, it is necessary to use a pressure regulating device to adjust the pressure.

[0003] Natural gas raw gas is transported at high pressure and needs to be reduced in pressure when it reaches the user terminal. The traditional pressure regulation method is to use a throttling valve to expand and reduce the pressure. The exergy loss is large during the throttling process, and this part of the reduced pressure is not utilized, resulting in a large amount of energy being wasted. If a turbine expander is used for pressure regulation, the pressure is reduced and the temperature is lowered during the pressure regulation process, which can generate a large amount of high-quality pressure energy and cold energy, but energy cannot be used effectively and cold recovery cannot be performed.

[0004] Therefore, it is necessary to study a new technical solution to solve the above problems. Summary of the invention

[0005] In view of this, the present invention aims to address the deficiencies in the prior art, and its main purpose is to provide an energy storage system based on a natural gas pipeline network. It effectively solves the problem of a large amount of energy being wasted when natural gas is depressurized in traditional technologies by adding a natural gas compressor, a waste heat utilization system, a natural gas high-pressure gas pipeline, a natural gas low-pressure gas pipeline, a turbine power generation device and a cold energy utilization system to the existing natural gas pipeline transmission terminal.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] An energy storage system based on a natural gas transmission pipeline network, comprising a natural gas compressor, a waste heat utilization system, a natural gas high-pressure transmission pipeline, a natural gas low-pressure transmission pipeline, a turbine power generation device and a cold energy utilization system;

[0008] The waste heat utilization system includes a natural gas cooler, a hot water tank, a radiator, a hot water heat exchanger and a cold water tank; the output end of the natural gas compressor is connected to the input end of the natural gas cooler;

[0009] The input end of the hot water pool is connected to the other input end of the natural gas, the output end of the hot water pool is connected to the input end of the radiator, the output end of the radiator is connected to the input end of the hot water heat exchanger, the output end of the hot water heat exchanger is connected to the input end of the cold water pool, and the output end of the cold water pool is connected to the other output end of the natural gas cooler;

[0010] The output end of the waste heat utilization system is connected to the input end of the natural gas high-pressure gas transmission pipeline, and the output end of the natural gas high-pressure gas transmission pipeline is connected to the input end of the natural gas low-pressure gas transmission pipeline; the output end of the natural gas low-pressure gas transmission pipeline is connected to the turbine power generation device, and the output end of the turbine power generation device is connected to the input end of the cold energy utilization system;

[0011] The cold energy utilization system includes a natural gas heater, a cold storage tank, a cold energy utilization device and a coolant storage tank; the output end of the cold storage tank is connected to the input end of the cold energy utilization device, the output end of the cold energy utilization device is connected to the input end of the coolant storage tank, and the output end of the coolant storage tank is connected to the other output end of the natural gas heater.

[0012] As a preferred solution, a first shut-off valve is further provided between the output end of the natural gas compressor and the input end of the natural gas cooler.

[0013] As a preferred solution, a second shut-off valve is further provided between the output end of the natural gas high-pressure gas transmission pipeline and the input end of the natural gas low-pressure gas transmission pipeline.

[0014] As a preferred solution, a hot water pump is further provided between the output end of the hot water tank and the input end of the radiator.

[0015] As a preferred solution, a hot water circulation pump is also provided between the output end of the cold water tank and the other output end of the natural gas cooler.

[0016] As a preferred solution, a working fluid pump is further provided between the output end of the cold storage tank and the input end of the cold energy utilization device.

[0017] As a preferred solution, a refrigerant circulation pump is also provided between the output end of the refrigerant storage tank and the other output end of the natural gas heater.

[0018] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical solution that it mainly adds a natural gas compressor, a waste heat utilization system, a natural gas high-pressure gas transmission pipeline, a natural gas low-pressure gas transmission pipeline, a turbine power generation device and a cold energy utilization system on the basis of the existing natural gas pipeline transmission terminal; in this way, natural gas is compressed and stored, which greatly reduces the cost of the energy storage system and enhances the peak load regulation capacity of natural gas. At the same time, it can achieve the dual benefits of storing natural gas and energy at night for use and power generation during the day;

[0019] And the setting of the waste heat utilization system. After the natural gas is pressurized by the natural gas compressor, the temperature rises, and it is first cooled by the natural gas cooler. The natural gas is cooled by cold water in the natural gas cooler and then sent to the hot water pool. The hot water in the hot water pool is sent to the radiator and the hot water heat exchanger through a hot water pump. At this time, the hot water in the hot water pool can be sent to nearby places that need heating for heating. After the temperature of the hot water is lowered, it is sent back to the cold water pool for storage. At this time, the cold water in the cold water pool is pressurized by a circulating pump at night and sent to the natural gas cooler to cool the natural gas, so that the obtained heat energy can be used for heating for users, realizing the recovery and utilization of heat energy;

[0020] The second is the setting of the cold energy utilization system. When releasing energy during the day, a turbine power generation device is used to adjust the pressure. The temperature of the natural gas after the turbine decreases. At this time, this part of the cold energy is recovered and output through the cold energy utilization device to provide cooling for users, realizing the recovery and utilization of cold energy and increasing the overall efficiency of energy storage.

[0021] In order to more clearly illustrate the structural features and effects of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the connection structure and process flow of an embodiment of the present invention.

[0023] Description of the accompanying drawings:

[0024] 1. Natural gas compressor 2. First shut-off valve

[0025] 3. Hot water pool 4. Hot water pump

[0026] 5. Radiator 6. Hot water heat exchanger

[0027] 7. Cold water pool; 8. Hot water circulation pump

[0028] 9. Natural gas cooler 10. Natural gas high-pressure transmission pipeline

[0029] 11. Second shut-off valve 12. Natural gas low-pressure transmission pipeline

[0030] 13. Turbine power generation device 14. Natural gas heater

[0031] 15. Cold storage tank 16. Working fluid pump

[0032] 17. Cold energy utilization device 18. Coolant storage tank

[0033] 19. Refrigerant circulation pump. DETAILED DESCRIPTION

[0034] Please refer to Figure 1 As shown, it shows the specific structure of an embodiment of the present invention.

[0035] An energy storage system based on a natural gas transmission network includes a natural gas compressor 1, a waste heat utilization system, a natural gas high-pressure transmission pipeline 10, a natural gas low-pressure transmission pipeline 12, a turbine power generation device 13 and a cold energy utilization system.

[0036] The waste heat utilization system includes a natural gas cooler 9, a hot water tank 3, a radiator 5, a hot water heat exchanger 6 and a cold water tank 7; the output end of the natural gas compressor 1 is connected to the input end of the natural gas cooler 9; preferably, a first shut-off valve 2 is also provided between the output end of the natural gas compressor 1 and the input end of the natural gas cooler 9.

[0037] The compressors in the original compression station are used, and compressors are added according to demand. When the natural gas in the upstream natural gas pipeline is transported to the terminal compressor station, it needs to be further pressurized. Energy storage is mainly carried out at night. In the last 1 to 3 hours of valley power at night, the natural gas compressor 1 is turned on to start compressing natural gas. When the compressor compresses the natural gas so that the natural gas in the natural gas low-pressure gas pipeline 12 is sufficient for use within the remaining valley power period of 2 to 3 hours, the first shut-off valve 2 is closed, and the natural gas compressor 1 is started at full load to compress the natural gas to the natural gas high-pressure gas pipeline 10 for storage until the valley power period ends, and the natural gas compressor 1 is turned off. The compressor in the original natural gas boosting station is used, and a new natural gas compressor 1 is added, which reduces the investment in energy storage and ensures the natural gas storage volume and pressure required for energy storage and gas storage.

[0038] The input end of the hot water tank 3 is connected to the other input end of the natural gas, and the output end of the hot water tank 3 is connected to the input end of the radiator 5. Preferably, a hot water circulation pump 8 is also provided between the output end of the cold water tank 7 and the other output end of the natural gas cooler 9.

[0039] The output end of the radiator 5 is connected to the input end of the hot water heat exchanger 6, the output end of the hot water heat exchanger 6 is connected to the input end of the cold water tank 7, and the output end of the cold water tank 7 is connected to the other output end of the natural gas cooler 9; preferably, a hot water pump 4 is also provided between the output end of the hot water tank 3 and the input end of the radiator 5.

[0040] The output end of the waste heat utilization system is connected to the input end of the natural gas high-pressure gas pipeline 10, and the output end of the natural gas high-pressure gas pipeline 10 is connected to the input end of the natural gas low-pressure gas pipeline 12; the output end of the natural gas low-pressure gas pipeline 12 is connected to the turbine power generation device 13, and the output end of the turbine power generation device 13 is connected to the input end of the cold energy utilization system; after the natural gas is pressurized by the natural gas compressor 1, the temperature rises, and it is first cooled by the natural gas cooler 9, and the natural gas is cooled by cold water in the natural gas cooler 9 and then sent to the hot water pool 3, and the hot water The hot water in the pool 3 is sent to the radiator 5 and the hot water heat exchanger 6 through the hot water pump 4. At this time, the hot water in the hot water pool 3 can be sent to nearby places that need heating for heating. After the temperature of the hot water is reduced, it is sent back to the cold water pool 7 for storage. At this time, the cold water in the cold water pool 7 is pressurized by the circulating pump at night and sent to the natural gas cooler 9 to cool the natural gas, so that the obtained heat energy can be used for heating for users, realizing the recovery and utilization of heat energy; preferably, a second shut-off valve 11 is also provided between the output end of the natural gas high-pressure gas transmission pipeline 10 and the input end of the natural gas low-pressure gas transmission pipeline 12.

[0041] The second shut-off valve 11 is usually open. When energy storage is needed at night, the natural gas compressor 1 is operated, and the pressure in the natural gas pipeline section increases. When the pressure of the stored natural gas in the natural gas low-pressure gas pipeline 12 is 1.5 to 2 times the normal gas transmission pressure, and the natural gas stored in the natural gas low-pressure gas pipeline 12 is sufficient for automatic gas transmission in the next 2 to 3 hours, the energy-releasing second shut-off valve 11 is closed. At this time, the downstream users rely on the high-pressure natural gas stored in the natural gas low-pressure gas pipeline 12 for automatic gas transmission; the natural gas compressor 1 continues to work for 2 to 3 hours until the high-pressure natural gas stored in the natural gas high-pressure gas pipeline 10 meets the gas transmission volume requirement of 8 to 12 hours during the day, and the natural gas compressor 1 stops working;

[0042] During the daytime energy release, the first shut-off valve 2 is closed and the second shut-off valve 11 is opened. The high-pressure natural gas in the natural gas high-pressure gas transmission pipeline 10 is used to release energy to transport natural gas, and the turbine power generation device 13 operates to generate electricity. The daytime energy release time is generally 8 to 12 hours. When the high-pressure natural gas in the natural gas low-pressure gas transmission pipeline 12 is completely released, the first shut-off valve 2 is opened, and the natural gas compressor 1 of the booster station starts to operate normally to transport natural gas to downstream users. This enhances the natural gas peak-shaving capacity, and at the same time can achieve the dual benefits of storing natural gas and energy at night for daytime use and power generation.

[0043] The cold energy utilization system includes a natural gas heater 14, a cold storage tank 15, a cold energy utilization device 17 and a coolant storage tank 18; the output end of the cold storage tank 15 is connected to the input end of the cold energy utilization device 17, the output end of the cold energy utilization device 17 is connected to the input end of the coolant storage tank, and the output end of the coolant storage tank is connected to the other output end of the natural gas heater 14. Preferably, a working fluid pump 16 is further provided between the output end of the cold storage tank 15 and the input end of the cold energy utilization device 17. Preferably, a refrigerant circulation pump 19 is further provided between the output end of the coolant storage tank 18 and the other output end of the natural gas heater 14.

[0044] During the daytime energy release, when the turbine power generation device 13 is running, the temperature of the natural gas after the turbine drops to -10 to -25°C, and the temperature after the natural gas needs to be restored. At the same time, this part of the low-temperature cold capacity needs to be utilized to increase the overall energy storage efficiency; after the low-temperature natural gas passes through the natural gas heater 14, it exchanges heat with the refrigerant to reduce the refrigerant temperature, and the natural gas temperature rises to above 0°C; the low-temperature refrigerant enters the cold storage tank 15 as a cold source, and is pressurized by the working fluid pump 16 and sent to the cold energy utilization device 17 for utilization, and the cold energy utilization device 17 can be used for ice making or air conditioning; after the refrigerant is heated, it enters the refrigerant storage tank 18 for storage. When the turbine power generation device 13 starts to release energy, the refrigerant is pressurized by the refrigerant circulation pump 19 and then enters the natural gas heater 14 for cooling, forming a cold energy utilization cycle.

[0045] The design focus of the present invention is that it mainly adds a natural gas compressor, a waste heat utilization system, a natural gas high-pressure gas transmission pipeline, a natural gas low-pressure gas transmission pipeline, a turbine power generation device and a cold energy utilization system on the basis of the existing natural gas pipeline transmission terminal; compresses and stores natural gas, greatly reducing the cost of the energy storage system, while enhancing the natural gas peak-shaving capacity, and can achieve the dual benefits of storing natural gas and energy at night for use and power generation during the day;

[0046] And the setting of the waste heat utilization system. After the natural gas is pressurized by the natural gas compressor, the temperature rises, and it is first cooled by the natural gas cooler. The natural gas is cooled by cold water in the natural gas cooler and then sent to the hot water pool. The hot water in the hot water pool is sent to the radiator and the hot water heat exchanger through a hot water pump. At this time, the hot water in the hot water pool can be sent to nearby places that need heating for heating. After the temperature of the hot water is lowered, it is sent back to the cold water pool for storage. At this time, the cold water in the cold water pool is pressurized by a circulating pump at night and sent to the natural gas cooler to cool the natural gas, so that the obtained heat energy can be used for heating for users, realizing the recovery and utilization of heat energy;

[0047] The second is the setting of the cold energy utilization system. When releasing energy during the day, a turbine power generation device is used to adjust the pressure. The temperature of the natural gas after the turbine decreases. At this time, this part of the cold energy is recovered and output through the cold energy utilization device to provide cooling for users, realizing the recovery and utilization of cold energy and increasing the overall efficiency of energy storage.

[0048] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An energy storage system based on a natural gas pipeline network, characterized in that: It includes natural gas compressor, waste heat utilization system, natural gas high-pressure gas transmission pipeline, natural gas low-pressure gas transmission pipeline, turbine power generation device and cold energy utilization system; The waste heat utilization system includes a natural gas cooler, a hot water tank, a radiator, a hot water heat exchanger and a cold water tank; the output end of the natural gas compressor is connected to the input end of the natural gas cooler; The input end of the hot water pool is connected to the other input end of the natural gas, the output end of the hot water pool is connected to the input end of the radiator, the output end of the radiator is connected to the input end of the hot water heat exchanger, the output end of the hot water heat exchanger is connected to the input end of the cold water pool, and the output end of the cold water pool is connected to the other output end of the natural gas cooler; The output end of the waste heat utilization system is connected to the input end of the natural gas high-pressure gas transmission pipeline, and the output end of the natural gas high-pressure gas transmission pipeline is connected to the input end of the natural gas low-pressure gas transmission pipeline; the output end of the natural gas low-pressure gas transmission pipeline is connected to the turbine power generation device, and the output end of the turbine power generation device is connected to the input end of the cold energy utilization system; The cold energy utilization system includes a natural gas heater, a cold storage tank, a cold energy utilization device and a coolant storage tank; the output end of the cold storage tank is connected to the input end of the cold energy utilization device, the output end of the cold energy utilization device is connected to the input end of the coolant storage tank, and the output end of the coolant storage tank is connected to the other output end of the natural gas heater.

2. The energy storage system based on the natural gas transmission pipeline network according to claim 1 is characterized in that: A first shut-off valve is also provided between the output end of the natural gas compressor and the input end of the natural gas cooler.

3. The energy storage system based on the natural gas transmission pipeline network according to claim 1 is characterized in that: A second shut-off valve is also provided between the output end of the natural gas high-pressure gas transmission pipeline and the input end of the natural gas low-pressure gas transmission pipeline.

4. The energy storage system based on the natural gas transmission pipeline network according to claim 1 is characterized in that: A hot water pump is also arranged between the output end of the hot water tank and the input end of the radiator.

5. The energy storage system based on the natural gas transmission pipeline network according to claim 1 is characterized in that: A hot water circulation pump is also provided between the output end of the cold water tank and the other output end of the natural gas cooler.

6. The energy storage system based on the natural gas transmission pipeline network according to claim 1 is characterized in that: A working fluid pump is also provided between the output end of the cold storage tank and the input end of the cold energy utilization device.

7. The energy storage system based on the natural gas transmission pipeline network according to claim 1 is characterized in that: A refrigerant circulation pump is also provided between the output end of the refrigerant storage tank and the other output end of the natural gas heater.

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