Heat energy recovery system based on natural gas conveying pipe network

Abstract

The utility model discloses a heat energy recovery system based on a natural gas conveying pipe network. The heat energy recovery 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 and a turbine power generation device. 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. 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; and the obtained heat energy can be used for supplying heat to users, so that the heat energy is recycled.

Description

Technical Field

[0001] The utility model relates to the field of heat energy recovery systems for natural gas pipeline networks, and in particular to a heat energy recovery system based on natural gas pipeline networks. Background Art

[0002] As more and more renewable energy sources, such as wind and solar power, are connected to the grid, their generation capacity is climbing year by year. However, their highly random and unstable nature poses significant challenges to the grid's power balance. When supply and demand are unbalanced, voltage fluctuations and frequency shifts can occur, degrading power quality. Energy storage systems are an effective means of addressing this imbalance. To accommodate the increasing proportion of renewable energy generation in the future, the country is placing higher demands on the development of new energy storage technologies.

[0003] As a highly efficient and clean energy source, natural gas has gained widespread application in recent years. Before entering city gate stations or gas-fired power plants, natural gas pipelines must undergo pressure reduction according to specific requirements before use. Natural gas transmission pressure is 6-8 MPa, while industrial gas pressure is approximately 0.3-3 MPa. Pressure regulating equipment is required to regulate the pressure before reaching natural gas users. Natural gas feedstock is transported at high pressure and requires pressure reduction upon reaching the user terminal. Traditional pressure regulation involves using a throttling valve to expand and reduce the pressure. However, this throttling process results in significant heat loss, and the reduced pressure remains unutilized, resulting in significant energy waste.

[0004] Therefore, it is necessary to study a new technical solution to solve the above problems. Utility Model Content

[0005] In view of this, the present invention aims to address the deficiencies in the existing technology, and its main purpose is to provide a heat recovery 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 decompressed in traditional technologies by adding 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 to the existing natural gas pipeline transmission terminal.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A heat recovery 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 and a turbine power generation device;

[0008] The output end of the waste heat utilization system is connected to the input end of the natural gas high-pressure gas pipeline, the output end of the natural gas high-pressure gas pipeline is connected to the input end of the natural gas low-pressure gas pipeline; the output end of the natural gas low-pressure gas pipeline is connected to the input end of the turbine power generation device;

[0009] 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;

[0010] 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.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] As a preferred solution, a hot water circulation pump is further provided between the output end of the cold water tank and the other output end of the natural gas cooler.

[0015] Compared with the existing technology, the present invention has obvious advantages and beneficial effects. Specifically, as can be seen from the above technical solution, 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 and a turbine power generation device to 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 natural gas peak-shaving capacity. 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.

[0016] 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 hot water temperature drops, 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 to heat the users, realizing the recovery and utilization of heat energy and increasing the overall energy storage efficiency.

[0017] In order to more clearly illustrate the structural features and effects of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the connection structure and process flow of an embodiment of the present utility model.

[0019] Description of the accompanying drawings:

[0020] 1. Natural gas compressor 2. First shut-off valve

[0021] 3. Hot water pool 4. Hot water pump

[0022] 5. Radiator 6. Hot water heat exchanger

[0023] 7. Cold water tank; 8. Hot water circulation pump

[0024] 9. Natural gas cooler 10. Natural gas high-pressure transmission pipeline

[0025] 11. Second shut-off valve 12. Natural gas low-pressure transmission pipeline

[0026] 13. Turbine power generation device. DETAILED DESCRIPTION

[0027] Please refer to Figure 1 As shown, it shows the specific structure of an embodiment of the present utility model.

[0028] A heat energy recovery system based on a natural gas transmission network includes a natural gas compressor 1, a waste heat utilization system, a natural gas high-pressure gas transmission pipeline 10, a natural gas low-pressure gas transmission pipeline 12 and a turbine power generation device 13.

[0029] 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.

[0030] The compressors at the original compression station are utilized, and additional compressors are added as needed. When the natural gas from 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. During the last 1 to 3 hours of off-peak electricity, the natural gas compressor 1 is turned on to start compressing natural gas. When the compressor compresses enough natural gas to allow the natural gas in the low-pressure natural gas transmission pipeline 12 to be used for the remaining 2 to 3 hours of off-peak electricity, 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 high-pressure natural gas transmission pipeline 10 for storage until the off-peak electricity period ends, at which point the natural gas compressor 1 is turned off. The compressors at the original natural gas boosting station are utilized, and a new natural gas compressor 1 is added, reducing the investment in energy storage while ensuring the natural gas storage volume and pressure required for energy and gas storage.

[0031] 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.

[0032] 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.

[0033] 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 first passes through the natural gas cooler 9 to cool down. The natural gas is cooled by cold water in the natural gas cooler 9 and then sent to the hot water pool 3. 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 hot water temperature drops, 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 circulation 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 to heat the 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.

[0034] The second shut-off valve 11 is normally 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 low-pressure natural gas pipeline 12 reaches 1.5 to 2 times the normal gas transmission pressure, and the natural gas stored in the low-pressure natural gas pipeline 12 is sufficient for automatic gas transmission for the next 2 to 3 hours, the energy-releasing second shut-off valve 11 is closed. At this time, downstream users automatically receive gas from the high-pressure natural gas stored in the low-pressure natural gas pipeline 12. The natural gas compressor 1 continues to operate for 2 to 3 hours until the high-pressure natural gas stored in the high-pressure natural gas pipeline 10 meets the gas transmission volume requirement for 8 to 12 hours during the day, at which time the natural gas compressor 1 stops operating.

[0035] 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 transmission pipeline 10 is used to release energy for natural gas transportation, and the turbine power generation device 13 operates to generate electricity. The energy release time during the day is generally 8 to 12 hours. After the high-pressure natural gas in the natural gas low-pressure transmission pipeline 12 is completely released, the first shut-off valve 2 is opened, and the natural gas compressor 1 of the boosting 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 use during the day and power generation.

[0036] The key design aspect of this utility model is that it adds a natural gas compressor, a waste heat utilization system, a high-pressure natural gas transmission pipeline, a low-pressure natural gas transmission pipeline, and a turbine power generation device to the existing natural gas pipeline transmission terminal. This compresses and stores natural gas, significantly reducing the cost of the energy storage system while enhancing the natural gas peak-shaving capacity. Furthermore, it can achieve the dual benefits of storing natural gas and energy at night for daytime use and power generation.

[0037] 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 hot water temperature drops, 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 to heat the users, realizing the recovery and utilization of heat energy and increasing the overall energy storage efficiency.

[0038] The above description is merely a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any minor 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. A heat recovery system based on a natural gas pipeline network, characterized by: It includes natural gas compressor, waste heat utilization system, natural gas high-pressure gas transmission pipeline, natural gas low-pressure gas transmission pipeline and turbine power generation device; The output end of the waste heat utilization system is connected to the input end of the natural gas high-pressure gas pipeline, the output end of the natural gas high-pressure gas pipeline is connected to the input end of the natural gas low-pressure gas pipeline; the output end of the natural gas low-pressure gas pipeline is connected to the input end of the turbine power generation device; 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.

2. The heat energy recovery system based on the natural gas pipeline network according to claim 1 is characterized in that: 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.

3. The heat energy recovery system based on the natural gas pipeline network according to claim 1 is characterized in that: 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.

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

5. The heat energy recovery system based on the natural gas 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.

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