CN116123764A - Totally-enclosed compressed gas liquefaction energy storage power generation system - Google Patents

Abstract

The invention discloses a totally-enclosed compressed gas liquefaction energy storage power generation system which comprises a compression system, a first heat exchange unit, a high-pressure gas-liquid storage container, a second heat exchange unit, a heat exchange system, an expansion system, a low-temperature expansion system and a low-pressure gas-liquid storage container. According to the invention, the circulating gas is liquefied and stored, so that the volume of the storage tank is greatly reduced; the direct heat exchange mode of the coexistence of high-temperature gas and low-temperature gas-liquid is adopted, so that the loss of secondary heat exchange efficiency is avoided, and the reaction speed of the system is increased; the full-closed circulation is realized, other substance input and output systems are not needed, and a direct heat exchange and low-temperature expansion machine combination mode is adopted, so that the heat exchange systems are fewer, and the device structure is simple; no combustible gas participates in circulation, so that pollution to the atmospheric environment is avoided; the volume is small, and the transportation is convenient; the subsystem can be added in the form of building blocks in the module according to the use requirement.

Description

A fully enclosed compressed gas liquefaction energy storage power generation system

technical field

The invention belongs to the technical field of compressed gas energy storage, and in particular relates to a fully enclosed compressed gas liquefaction energy storage power generation system.

Background technique

At present, the whole world is vigorously developing green energy power generation technologies, such as wind power, tidal energy, hydropower, solar energy, etc., but these power generation have obvious peak and valley effects, resulting in frequent fluctuations in power grid transmission frequency. In order to better shave peaks and fill valleys and ensure the normal operation of equipment, it is necessary to use reliable energy storage devices to participate in the adjustment.

Compressed air energy storage is to compress the external air into high-pressure air, so as to convert excess electric energy into internal energy and store it; when the electric energy is to be released, the high-pressure air is used to drive the expansion system to do work to release electric energy, which has high energy storage energy density and no pollution Compared with other methods, the external environment is smaller in size and so on. However, it still has the following disadvantages: the volume of the air storage tank is still large, which is inconvenient to transport and use; the components are strongly related and cannot be used separately; air still needs to participate in the internal and external exchange of the cycle, and there are requirements for the use environment and air purity. The difficulty of using the device.

Contents of the invention

Technical problem to be solved: In view of the above technical problems, the present invention provides a fully enclosed compressed gas liquefaction energy storage power generation system, which can effectively solve the above-mentioned shortcomings of the compressed air energy storage device, such as large volume, single use environment, poor portability, and inability to arrange in points place.

Technical solution: A fully enclosed compressed gas liquefaction energy storage power generation system, including a compression system, a first heat exchange unit, a high-pressure gas-liquid storage container, a second heat exchange unit, a heat exchange system, an expansion system, a low-temperature expansion system and a low-pressure gas A liquid storage container, the compression system includes a motor and a compressor unit, the compressor unit is electrically connected to the motor; the first heat exchange unit includes a first channel, a second channel, a third channel and a fourth channel arranged in parallel; The second heat exchange unit includes a fifth channel and a sixth channel arranged side by side; the heat exchange system includes a low-temperature tank and a high-temperature tank; the expansion system includes an expander and a first generator, and the expander and the first generator A generator is electrically connected; the low-temperature expansion system includes a low-temperature expander and a second generator, and the low-temperature expander is electrically connected to the second generator;

The outlet of the compressor unit is connected to the inlet of the first channel, the outlet of the first channel is connected to the inlet of the high-pressure gas-liquid storage container, the outlet of the high-pressure gas-liquid storage container is connected to the inlet of the fifth channel, and the The outlet of the fifth channel is connected to the inlet of the expander, the outlet of the expander is connected to the inlet of the low-temperature expander, the outlet of the low-temperature expander is connected to the inlet of the low-pressure gas-liquid storage container, and the low-pressure gas-liquid storage container The outlet of the third channel is connected to the inlet of the third channel, the outlet of the third channel is connected to the inlet of the compressor unit, the outlet of the low temperature tank is connected to the inlet of the second channel, and the outlet of the second channel is connected to the inlet of the high temperature tank , the first outlet of the high-temperature tank is connected to the inlet of the sixth passage, the outlet of the sixth passage is connected to the inlet of the low-temperature tank, the second outlet of the high-temperature tank is connected to the inlet of the fourth passage, and the first The outlets of the four channels are connected to the inlets of the cryogenic tank.

Preferably, a first valve is provided on the pipe connecting the outlet of the first passage to the inlet of the high-pressure gas-liquid storage container, and a second valve is provided on the pipe connecting the outlet of the high-pressure gas-liquid storage container to the inlet of the fifth passage. Two valves, a third valve is provided on the pipe connecting the outlet of the second passage to the inlet of the high-temperature tank, and a fourth valve is provided on the pipe connecting the second outlet of the high-temperature tank to the inlet of the fourth passage, so A fifth valve is provided on the pipe connecting the first outlet of the high-temperature tank to the inlet of the sixth passage, and a sixth valve is provided on the pipe connecting the outlet of the low-temperature expander to the inlet of the low-pressure gas-liquid storage container. A seventh valve is arranged on the pipeline connecting the outlet of the low-pressure gas-liquid storage container with the inlet of the third channel.

Preferably, the compressor unit is one or more of axial compressors, centrifugal compressors, mixed flow compressors, reciprocating compressors, scroll compressors, and screw compressors in series or in parallel.

Preferably, the expander is one or more of axial flow expanders, centripetal expanders, mixed flow expanders, and reciprocating expanders connected in series or in parallel.

Preferably, the compressor unit is provided with an initial medium inlet.

Further, the initial medium is one or a mixture of air, carbon dioxide, and helium.

Preferably, the heat exchange medium between the low temperature tank and the high temperature tank is water, air, paraffin, biomass oil, heat conduction oil, inorganic crystalline hydrated salt, molten salt, organic fatty acid, propane or glycol solution.

Beneficial effects: in terms of volume: the circulating gas is liquefied and stored, greatly reducing the volume of the storage tank;

Efficiency: Direct heat exchange between high-temperature gas and low-temperature gas-liquid coexistence is adopted to avoid loss of secondary heat exchange efficiency and speed up system response;

Structurally: fully enclosed circulation, no other material input and output systems, the combination of direct heat exchange and low-temperature expander is adopted, so that the heat exchange system is less and the device structure is simple;

Environmental protection: no flammable gas participates in the cycle, avoiding pollution to the atmospheric environment;

Portability: small size, easy to transport;

In terms of specifications: Subsystems can be added in the form of building blocks in the module according to the usage requirements.

Description of drawings

Fig. 1 is a schematic diagram of a fully enclosed compressed gas liquefaction energy storage power generation system of the present invention;

Fig. 2 is a structural schematic diagram of the initial stage of compressed gas energy storage in Fig. 1;

Fig. 3 is a structural schematic diagram of the complete stage of compressed gas energy storage in Fig. 1;

Fig. 4 is a structural schematic diagram of the energy release stage of the expanding gas in Fig. 1;

Serial numbers in the figure: 1. Compression system, 11. Motor, 12. Compressor unit, 2. First heat exchange unit, 21. First channel, 22. Second channel, 23. Third channel, 24. Fourth channel, 31. First valve, 32. Second valve, 33. Third valve, 34. Fifth valve, 36. Sixth valve, 37. Seventh valve, 4. High-pressure gas-liquid storage container, 5. Heat exchange system, 51. Low temperature tank, 52. High temperature tank, 6. Second heat exchange unit, 61. Fifth channel, 62. Sixth channel, 7. Expansion system, 71. Expander, 72. First generator, 8. Low temperature Expansion system, 81, low-temperature expander, 82, second generator, 9, low-pressure gas-liquid storage container.

Implementation

Below in conjunction with accompanying drawing and specific embodiment the present invention is described in detail:

Example

As shown in Figure 1, a fully enclosed compressed gas liquefaction energy storage power generation system includes a compression system 1, a first heat exchange unit 2, a high-pressure gas-liquid storage container 4, a second heat exchange unit 6, a heat exchange system 5, an expansion System 7, low-temperature expansion system 8 and low-pressure gas-liquid storage container 9, the compression system 1 includes a motor 11 and a compressor unit 12, the compressor unit 12 is electrically connected to the motor 11; the first heat exchange unit 2 includes a parallel arrangement The first channel 21, the second channel 22, the third channel 23 and the fourth channel 24; the second heat exchange unit 6 includes the fifth channel 61 and the sixth channel 62 arranged side by side; the heat exchange system 5 includes Low-temperature tank 51 and high-temperature tank 52; the expansion system 7 includes an expander 71 and a first generator 72, and the expander 71 is electrically connected to the first generator 72; the low-temperature expansion system 8 includes a low-temperature expander 81 and A second generator 82, the low temperature expander 81 is electrically connected to the second generator 82;

The outlet of the compressor unit 12 is connected to the inlet of the first passage 21, the outlet of the first passage 21 is connected to the inlet of the high-pressure gas-liquid storage container 4, and the outlet of the high-pressure gas-liquid storage container 4 is connected to the fifth passage 61 The inlet of the fifth passage 61 is connected to the inlet of the expander 71, the outlet of the expander 71 is connected to the inlet of the low-temperature expander 81, and the outlet of the low-temperature expander 81 is connected to the low-pressure gas-liquid storage container 9, the outlet of the low-pressure gas-liquid storage container 9 is connected to the inlet of the third passage 23, the outlet of the third passage 23 is connected to the inlet of the compressor unit 12, and the outlet of the cryogenic tank 51 is connected to the second passage 22, the outlet of the second channel 22 is connected to the inlet of the high temperature tank 52, the first outlet of the high temperature tank 52 is connected to the inlet of the sixth channel 62, and the outlet of the sixth channel 62 is connected to the low temperature tank 51, the second outlet of the high temperature tank 52 is connected to the inlet of the fourth channel 24, and the outlet of the fourth channel 24 is connected to the inlet of the low temperature tank 51.

A first valve 31 is provided on the pipeline connecting the outlet of the first channel 21 to the inlet of the high-pressure gas-liquid storage container 4, and a first valve 31 is provided on the pipeline connecting the outlet of the high-pressure gas-liquid storage container 4 to the inlet of the fifth channel 61. Second valve 32, a third valve 33 is provided on the pipeline connecting the outlet of the second passage 22 with the inlet of the high-temperature tank 52, and a third valve 33 is arranged on the pipeline connected between the second outlet of the high-temperature tank 52 and the inlet of the fourth passage 24 A fourth valve 34 is provided, a fifth valve 35 is provided on the pipeline connecting the first outlet of the high-temperature tank 52 with the inlet of the sixth passage 62, and the outlet of the low-temperature expander 81 is connected to the outlet of the low-pressure gas-liquid storage container 9. A sixth valve 36 is provided on the pipeline connected to the inlet, and a seventh valve 37 is provided on the pipeline connected to the outlet of the low-pressure gas-liquid storage container 9 and the inlet of the third channel 23 .

The above-mentioned compressor unit 12 is one or more of axial flow compressors, centrifugal compressors, mixed flow compressors, reciprocating compressors, scroll compressors, and screw compressors connected in series or in parallel.

The aforementioned expander 71 is one or more of axial flow expanders, centripetal expanders, mixed flow expanders, and reciprocating expanders connected in series or in parallel.

The above-mentioned compressor unit 12 is provided with an initial medium inlet.

The above-mentioned initial medium is one or a mixture of air, carbon dioxide, and helium.

The heat exchange medium between the low temperature tank 51 and the high temperature tank 52 is water, air, paraffin, biomass oil, heat conduction oil, inorganic crystalline hydrated salt, molten salt, organic fatty acid, propane or glycol solution.

The working principle of the system of the present invention is as follows: the boiling point of the gas increases with the increase of the air pressure, and the gaseous state is after the boiling point is exceeded, and the liquid state is lower than the boiling point. In the initial stage of compression energy storage, the amount of gas that can enter the compression system to do work in the low-pressure gas-liquid coexistence body is small, resulting in less heat released by the high-temperature and high-pressure gas, and the operation efficiency of the compression energy storage system is low. In order to change this state and maximize To maximize the utilization of system efficiency, this system sets the initial stage of compression energy storage, and uses the heat exchange system to accelerate the heat absorption and gasification of the low-pressure gas-liquid coexistence so as to reach the optimal operation stage of the compression energy storage system as soon as possible; when the high-temperature and high-pressure gas is released When the heat meets the heat required for the gasification of the low-pressure gas-liquid coexistence body, close the heat released by the heat exchange system to the low-pressure coexistence body, and open the valve of the high-temperature tank to release the high-temperature and high-pressure gas to the excess heat after the heat of the low-pressure gas-liquid coexistence body Stored, this can avoid the heat loss and inefficiency caused by the high temperature and high pressure gas and low pressure gas-liquid coexistence of the heat exchange system as the heat exchange medium. In the energy release link of the expansion gas, the high-pressure gas-liquid coexistence body expands and vaporizes by absorbing the heat energy stored in the heat exchange system, transports it to the expansion system to perform work and releases electric energy, and then goes through the low-temperature expander to further reduce the pressure and temperature to liquefy for storage.

The initial stage of compressed gas energy storage: in the case of low operating efficiency of the energy storage system and insufficient heat release of high-temperature and high-pressure gas, the operation of the heat exchange system releases heat to the low-pressure gas-liquid coexistence body to accelerate gasification, so that the compressed energy storage system can operate in a relatively short period of time. High operating efficiency can be achieved within a short period of time. The specific operation process is: open the first valve 31, the seventh valve 37 and the fourth valve 34, keep the third valve 33, the sixth valve 36, the second valve 32 and the fifth valve 35 closed, the schematic diagram of its structure is shown in Figure 2 As shown, the gas-liquid coexistence body stored in the low-pressure gas-liquid storage container 9 is transported to the third channel 23 in the first heat exchange unit 2, and then enters the compressor unit 12 in the compression system 1 after absorbing heat, expanding and gasifying, The motor 11 drives the compressor unit 12 to do work to compress the gas, and the high-temperature and high-pressure gas output from the compressor unit 12 enters the first channel 21 in the first heat exchange unit 2 to release heat and liquefy, and then transport it to the high-pressure gas-liquid storage container 4; high temperature The heat exchange medium in the tank 52 flows out to the fourth channel 24 in the first heat exchange unit 2 through the fourth valve 34 to release heat, and the heat exchange medium after releasing heat is delivered to the low temperature tank 51 .

Complete stage of compressed gas energy storage: With the further development of the system, it enters the complete stage of compressed gas energy storage, using high-temperature, high-pressure gas and low-pressure gas-liquid coexistence body for direct heat exchange, which can reduce the heat loss and efficiency of the heat exchange medium in the heat exchange system Low, slow system response and other disadvantages, and the heat exchange system is used to store the heat energy released by the liquefaction of high-temperature and high-pressure gas, and keep the first valve 31 and the seventh valve 37 open. The three valves 33 are fully opened, so that the heat exchange medium in the low temperature tank 51 is transported to the second channel 22 in the first heat exchange unit 2 to absorb heat, and then transported to the high temperature tank 52 for storage, and the fourth valve is gradually closed 34 until it is fully closed, reducing the heat exchange system 5's participation in the process of absorbing heat and gasifying the low-pressure gas-liquid coexistence body.

Expansion gas energy release stage: close the first valve 31, the seventh valve 37 and the third valve 33, keep the fourth valve 34 closed, open the second valve 32, the sixth valve 36 and the fifth valve 35, the schematic diagram of its structure is shown in the figure As shown in 4, the gas-liquid coexistence stored in the high-pressure gas-liquid storage container 4 is transported to the fifth channel 61 in the second heat exchange unit 6 to absorb heat, expand and gasify to form high-temperature and high-pressure gas, and then transport to the expansion system 7 The expander 71 works, and the expander 71 drives the first generator 72 to output electric energy. After passing through the expansion system 7, the output gas enters the low-temperature expander 81 in the low-temperature expansion system 8 to expand again to perform work, and the low-temperature expander 81 drives the second generator. 82 outputs electric energy, and the gas is liquefied and transported to the low-pressure gas-liquid storage container 9 after the temperature and pressure are lowered by the low-temperature expander 81 . The heat exchange medium in the high temperature tank 52 is sent to the sixth channel 62 of the second heat exchange unit 6 through the fifth valve 35 to release heat, and then sent to the low temperature tank 51 for storage.

The initial medium used in the system can be any gas that is easy to convert between gas and liquid, and the preferred initial medium is one or a mixture of air, carbon dioxide, and helium. Taking carbon dioxide as an example, when the temperature is -56.5°C, its saturation pressure is 0.422MPa, and when the temperature is 31°C, its saturation pressure is 7.376MPa. It is conservatively estimated that it can provide a compression ratio of more than 16 times.

A fully enclosed compressed gas liquefaction energy storage power generation system of the present invention has no other energy sources and substances involved in internal and external exchange except electric energy; the compressed gas energy storage stage is divided into two stages of operation: the first initial stage is low in system operation efficiency, high temperature and high pressure In the case of insufficient gas heat release, a heat exchange system is added to release heat to the low-pressure gas-liquid coexistence body to accelerate gasification so that the compressed energy storage system can achieve higher operating efficiency in a short period of time; the second complete stage uses high-temperature and high-pressure gas to directly communicate with low-pressure gas The heat exchange of the liquid coexistence body reduces the heat loss, low efficiency, and slow system response caused by the heat exchange system as the heat exchange medium, and the heat exchange system is used to store the heat energy released by the liquefaction of high-temperature and high-pressure gas; the use of cryopumps The form liquefies low-pressure gas, combined with segmented energy storage, the system only needs one heat exchange system. Compared with other compressed gas liquefaction energy storage systems, the number of heat exchange systems is reduced, which greatly reduces system complexity and installation difficulty.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (7)

1. A totally-enclosed compressed gas liquefaction energy storage power generation system is characterized in that: comprises a compression system, a first heat exchange unit, a high-pressure gas-liquid storage container, a second heat exchange unit, a heat exchange system, an expansion system, a low-temperature expansion system and a low-pressure gas-liquid storage container,

the compression system comprises a motor and a compressor unit, and the compressor unit is electrically connected with the motor;

the first heat exchange unit comprises a first channel, a second channel, a third channel and a fourth channel which are arranged in parallel;

the second heat exchange unit comprises a fifth channel and a sixth channel which are arranged in parallel;

the heat exchange system comprises a low-temperature tank and a high-temperature tank;

the expansion system comprises an expander and a first generator, and the expander is electrically connected with the first generator;

the low-temperature expansion system comprises a low-temperature expansion machine and a second generator, and the low-temperature expansion machine is electrically connected with the second generator;

the outlet of the compressor unit is connected with the inlet of the first channel, the outlet of the first channel is connected with the inlet of the high-pressure gas-liquid storage container, the outlet of the high-pressure gas-liquid storage container is connected with the inlet of the fifth channel, the outlet of the fifth channel is connected with the inlet of the expander, the outlet of the expander is connected with the inlet of the low-temperature expander, the outlet of the low-temperature expander is connected with the inlet of the low-pressure gas-liquid storage container, the outlet of the low-pressure gas-liquid storage container is connected with the inlet of the third channel, the outlet of the third channel is connected with the inlet of the compressor unit, the outlet of the low-temperature tank is connected with the inlet of the second channel, the outlet of the second channel is connected with the inlet of the high-temperature tank, the first outlet of the high-temperature tank is connected with the inlet of the sixth channel, the outlet of the sixth channel is connected with the inlet of the low-temperature tank, the second outlet of the high-temperature tank is connected with the inlet of the fourth channel, and the outlet of the fourth channel is connected with the inlet of the low-temperature tank.

2. The totally enclosed compressed gas liquefaction energy storage power generation system of claim 1, wherein: the pipeline that the export of first passageway and high-pressure gas-liquid storage container's access connection is equipped with first valve, be equipped with the second valve on the pipeline that the export of high-pressure gas-liquid storage container and the access connection of fifth passageway, be equipped with the third valve on the pipeline that the export of second passageway and the access connection of high temperature jar, be equipped with the fourth valve on the pipeline that the second export of high temperature jar and the access connection of fourth passageway, be equipped with the fifth valve on the pipeline that the first export of high temperature jar and the access connection of sixth passageway, be equipped with the sixth valve on the pipeline that the export of low temperature expander and the access connection of low-pressure gas-liquid storage container, be equipped with the seventh valve on the pipeline that the export of low-pressure gas-liquid storage container and the access connection of third passageway.

3. The totally enclosed compressed gas liquefaction energy storage power generation system of claim 1, wherein: the compressor unit is one or more of an axial flow compressor, a centrifugal compressor, a mixed flow compressor, a reciprocating compressor, a vortex compressor and a screw compressor which are connected in series or in parallel.

4. The totally enclosed compressed gas liquefaction energy storage power generation system of claim 1, wherein: the axial flow expander, the centripetal expander, the mixed flow expander and the reciprocating expander are connected in series or in parallel.

5. The totally enclosed compressed gas liquefaction energy storage power generation system of claim 1, wherein: the compressor package is provided with an initial medium inlet.

6. The totally enclosed compressed gas liquefaction energy storage power generation system of claim 5, wherein: the initial medium is one or a mixture of more of air, carbon dioxide and helium.

7. The totally enclosed compressed gas liquefaction energy storage power generation system of claim 1, wherein: the heat exchange medium between the low temperature tank and the high temperature tank is water, air, paraffin, biomass oil, heat conducting oil, inorganic crystalline hydrated salt, molten salt, organic fatty acid, propane or glycol solution.

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