Intensive mixed gas energy storage system

Abstract

The utility model discloses an intensive mixed gas energy storage system, which is characterized in that a pressure sensor A, a pressure sensor B and a gas film pressure release valve are additionally arranged on a constant-pressure diaphragm gas pressure tank, and the pressure sensor A, the pressure sensor B and the gas film pressure release valve are respectively and electrically connected with a controller; when the pressure difference between the pressure value, fed back by the pressure sensor A, of the first cavity and the pressure value, fed back by the pressure sensor B, of the second cavity, received by the controller reaches a set threshold value, the carbon dioxide energy storage subsystem or the air compression energy release subsystem which is running is controlled to stop running in order; meanwhile, a control signal for opening operation is sent to the gas film pressure release valve, carbon dioxide in the second cavity is discharged into the first cavity, gas pressure balance inside and outside the gas film is formed, the safety of the gas film is ensured, and therefore the situation that when certain equipment breaks down or the tank leaks, the pressure in the gas film is larger than the pressure outside the gas film is avoided; and the gas film is gradually increased to reach the limit and fractures to cause further loss.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage systems, in particular to an intensive mixed gas energy storage system. Background Art

[0002] Compressed air energy storage technology is a physical energy storage technology that uses compressed air to store energy. It has the advantages of large energy storage capacity, high safety, economy, environmental protection and mature technology. It plays an important role in future energy systems, especially in promoting the use of renewable energy and improving grid stability.

[0003] Carbon dioxide energy storage (CES) is a new physical energy storage technology based on compressed air energy storage (CAES) and the Brayton power generation cycle. In existing applications, CO2 energy storage utilizes low electricity prices to convert atmospheric-pressure gaseous CO2 into high-pressure liquid CO2 using a multi-stage compressor, converting electrical energy into CO2 internal energy for storage. During peak electricity demand, a multi-stage expander expands the high-pressure liquid CO2 into atmospheric-pressure gaseous CO2, which is then used to generate electricity, ultimately achieving both energy storage and release. However, this system has several drawbacks: 1. The equipment investment is substantial. The entire system consists of a low-pressure gas storage silo, a high-pressure storage tank, a compressor unit, a turbine unit, a heat exchange system, and numerous cold and heat storage tanks. The low-pressure gas storage silo, which stores CO2 at atmospheric pressure, requires a 10MW CO2 energy storage system, for example, requiring a silo of 1 million cubic meters. This would require substantial land costs in developed regions. The investment costs of these systems are substantial, and the technology's promotional costs should not be overlooked. ② Some energy storage solutions use two or more media, utilizing breathing air tanks with air membranes for medium-pressure energy storage. However, these membranes are susceptible to various uncertainties, leading to pressure imbalances inside and outside the membranes, ultimately posing the risk of explosion and rupture. This requires improvement. Utility Model Content

[0004] A technical problem to be solved by the present application is to overcome the defects of the above-mentioned related technologies and provide an intensive mixed gas energy storage system with a constant pressure diaphragm air pressure tank that is safe to use and has low construction cost.

[0005] The technical solution adopted by the present invention to solve the technical problem is: an intensive mixed gas energy storage system, including a controller, a constant pressure diaphragm air pressure tank and a carbon dioxide energy storage subsystem and an air compression energy release subsystem connected to the constant pressure diaphragm air pressure tank; the constant pressure diaphragm air pressure tank includes a tank body, an air film is provided in the tank body, the first cavity in the tank body is used to store air, the tank body is provided with an air inlet and an air outlet of the first cavity, the second cavity in the air film is used to store carbon dioxide, and the air film is connected to an air inlet pipe and an air outlet pipe of the second cavity that passes through the tank body; the constant pressure diaphragm air pressure tank is also provided with a pressure sensor A for monitoring the first cavity, a pressure sensor B for monitoring the second cavity and an air film pressure relief valve installed on the air film, and the pressure sensor A, pressure sensor B and air film pressure relief valve are electrically connected to the controller respectively.

[0006] Compared with the related technologies, the present invention has the following advantages: it adopts two compressed energy storage media, replaces carbon dioxide with air at the low-pressure end, eliminates the large carbon dioxide gas storage tank at the low-pressure end of traditional carbon dioxide energy storage, replaces it with inexhaustible air, and directly discharges it into the atmosphere during the energy release stage, which greatly reduces the equipment cost and medium cost of the low-pressure gas storage end; an underground constant-pressure diaphragm air pressure tank is used at the medium-pressure gas storage end, and the alternation of air and carbon dioxide energy storage media is completed through the contraction / expansion of the air film, so as to achieve the pressure stabilization effect in the two stages of energy storage and energy release; its constant-pressure diaphragm air pressure tank is additionally provided with a pressure sensor A for monitoring the first cavity, a pressure sensor B for monitoring the second cavity and an air film pressure relief valve installed on the air film, and the pressure sensor A, the pressure sensor B and the air film pressure relief valve are electrically connected to the controller respectively, and when the controller receives When the pressure difference between the pressure value of the first cavity fed back by pressure sensor A and the pressure value of the second cavity fed back by pressure sensor B reaches the set threshold, the controller controls the running carbon dioxide energy storage subsystem or air compression energy release subsystem to stop running in an orderly manner. At the same time, the controller sends a control signal for opening operation to the air film pressure relief valve to discharge the carbon dioxide in the second cavity into the first cavity, forming an air pressure balance inside and outside the air film to ensure the safety of the air film. When the pressure value of the first cavity fed back by pressure sensor A and the pressure value of the second cavity fed back by pressure sensor B are balanced, the controller sends a control signal for closing operation to the air film pressure relief valve, thereby avoiding the situation where the pressure inside the air film is greater than the pressure outside the air film due to a failure of a certain equipment or a leakage of the tank, and the air film gradually increases to the limit and ruptures, causing further losses.

[0007] Preferably, the energy storage component of the carbon dioxide energy storage subsystem includes the second cavity and the carbon dioxide compressor, the first heat exchanger, the second heat exchanger and the carbon dioxide storage tank; the energy release component of the carbon dioxide energy storage subsystem includes the carbon dioxide storage tank, the throttling pressure reducing valve, the third heat exchanger, the fourth heat exchanger and the carbon dioxide turbine and the second cavity; the heat exchange component of the carbon dioxide energy storage subsystem includes a hot-end water storage tank and a cold-end water storage tank, as well as a heat storage tank, a cold storage tank and a heat pump; the first heat exchanger and the hot-end water storage tank, the fourth heat exchanger and the cold-end water storage tank are connected to a first heat exchange circulation pipeline, and the second heat exchanger and the heat pump, the heat storage tank, the third heat exchanger and the cold storage tank are connected to a second heat exchange circulation pipeline.

[0008] Preferably, the compression component of the air compression energy release subsystem includes a first-stage air compressor, a fifth heat exchanger, a second-stage air compressor, a sixth heat exchanger and the first cavity; the energy release component of the air compression energy release subsystem includes the first cavity and the seventh heat exchanger, a first-stage air turbine, an eighth heat exchanger and a second-stage air turbine; the fifth heat exchanger, the sixth heat exchanger, the seventh heat exchanger and the eighth heat exchanger are respectively connected to the heat exchange inlet and outlet pipes and are connected in parallel to the first heat exchange circulation pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a connection diagram of the intensive mixed gas energy storage system of this application (controller omitted).

[0010] Figure 2 yes Figure 1 Enlarged schematic diagram of point S in the middle. DETAILED DESCRIPTION

[0011] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of the present application and are not intended to limit the scope of protection of the embodiments of the present application. Those skilled in the art may adjust them as needed to suit specific application scenarios.

[0012] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0013] This preferred embodiment is as follows Figure 1An intensive mixed gas energy storage system shown in the figure includes a controller (not shown in the figure), a constant pressure diaphragm air pressure tank, and a carbon dioxide energy storage subsystem and an air compression energy release subsystem connected to the constant pressure diaphragm air pressure tank; the constant pressure diaphragm air pressure tank includes a tank body 101, a gas membrane 102 is provided in the tank body 101, the first cavity in the tank body 101 is used to store air, the tank body 101 is provided with an air inlet and an air outlet of the first cavity, the second cavity in the gas membrane 102 is used to store carbon dioxide, and the gas membrane 102 is connected to the air inlet pipe and the air outlet pipe of the second cavity that passes through the tank body 101; the constant pressure diaphragm air pressure tank is also provided with a pressure sensor A103 for monitoring the first cavity, a pressure sensor B104 for monitoring the second cavity, and an air membrane pressure relief valve 105 installed on the air membrane 102, and the pressure sensor A103, pressure sensor B104 and air membrane pressure relief valve 105 are electrically connected to the controller respectively. During the process of the air film 102 growing, the entire process is not easy to be detected due to the very large volume of the metal tank body 101 and the air film 102. When the pressure difference between the pressure value of the first cavity fed back by the pressure sensor A103 and the pressure value of the second cavity fed back by the pressure sensor B104 reaches the set threshold, the controller can promptly control the running carbon dioxide energy storage subsystem or the air compression energy release subsystem to stop running in an orderly manner. At the same time, the controller sends a control signal for the opening operation to the air film pressure relief valve 105 to discharge the carbon dioxide in the second cavity into the first cavity, forming an air pressure balance inside and outside the air film to ensure the safety of the air film. When the pressure value of the first cavity fed back by the pressure sensor A103 and the pressure value of the second cavity fed back by the pressure sensor B104 are balanced, the controller sends a control signal for the closing operation to the air film pressure relief valve 105, thereby avoiding the situation where the pressure inside the air film is greater than the pressure outside the air film due to a device failure or a tank leak, and the air film gradually increases to the limit and ruptures, causing further losses.

[0014] In this embodiment, the controller adopts PLC, and the air film pressure relief valve 105 adopts a normally closed self-locking solenoid valve; the controller is also connected to a wireless communication module. When the air film pressure relief valve 105 needs to be opened, an alarm signal is synchronously sent to the safety administrator and maintenance personnel through the wireless communication module, so that the constant pressure diaphragm air pressure tank can be repaired in time.

[0015] The CO2 energy storage subsystem's energy storage components include the second chamber and CO2 compressor, a first heat exchanger (heat exchanger 1), a second heat exchanger (heat exchanger 2), and a CO2 liquid storage tank. The CO2 energy storage subsystem's energy release components include the CO2 liquid storage tank, a throttling and pressure reducing valve, a third heat exchanger (heat exchanger 3), a fourth heat exchanger (heat exchanger 4), a CO2 turbine, and the second chamber. The CO2 energy storage subsystem's heat exchange components include a hot-end water storage tank (indicated in the figure by hot-end (water) 194°C), a cold-end water storage tank (indicated in the figure by cold-end (water) 40°C), a thermal storage tank, a cold storage tank, and a heat pump. A first heat exchange circulation pipeline connects the first heat exchanger to the hot-end water storage tank, the fourth heat exchanger, and the cold-end water storage tank. A second heat exchange circulation pipeline connects the second heat exchanger to the heat pump, the thermal storage tank, the third heat exchanger, and the cold storage tank. The turbine is also referred to as a turbine expansion generator, the same below.

[0016] Among them, the compression components of the air compression energy release subsystem include a first-stage air compressor, a fifth heat exchanger (heat exchanger 5), a second-stage air compressor and a sixth heat exchanger (heat exchanger 6) and the first cavity; the energy release components of the air compression energy release subsystem include the first cavity and the seventh heat exchanger (heat exchanger 7), a first-stage air turbine, an eighth heat exchanger (heat exchanger 8) and a second-stage air turbine; the fifth heat exchanger, the sixth heat exchanger, the seventh heat exchanger and the eighth heat exchanger are respectively connected to the heat exchange inlet and outlet pipes and connected in parallel to the first heat exchange circulation pipeline.

[0017] As an improvement, the gas storage pressure of the constant pressure diaphragm air pressure tank is 1.5 MPa, and it is buried underground, using the underground pressure to offset part of the expansion pressure of the constant pressure diaphragm air pressure tank.

[0018] The energy storage method using the above-mentioned intensive mixed gas energy storage system for energy storage specifically includes the following process:

[0019] Energy storage stage: During the low-peak period of electricity consumption at night, the 1.5Mpa medium-pressure gaseous carbon dioxide in the second chamber of the underground constant-pressure diaphragm air pressure tank is compressed by the carbon dioxide compressor to form 7.2Mpa 196℃ high-pressure and high-temperature gaseous carbon dioxide. The 7.2Mpa 196℃ high-pressure and high-temperature gaseous carbon dioxide is cooled to 50℃ by the first heat exchanger, and the heat energy is stored in the hot end water storage tank at 7.2Mpa. The 50°C gaseous carbon dioxide is cooled and liquefied through the second heat exchanger to form 7.2Mpa 30°C liquid carbon dioxide and stored in the carbon dioxide storage tank; at the same time, when the gaseous carbon dioxide in the second cavity gradually decreases, in order to maintain a stable output pressure of 1.5Mpa of carbon dioxide, the pressure values ​​of pressure sensor A103 and pressure sensor B104 are kept at 1.5Mpa, and the first-stage air compressor and the second-stage air compressor begin to compress the air in the atmosphere. The heat generated during the air compression process is cooled through the fifth heat exchanger and the sixth heat exchanger, and the heat is stored in the hot end water storage tank, forming 1.5Mpa 45°C air stored in the first cavity of the constant pressure diaphragm air pressure tank underground.

[0020] Energy release stage: During the peak period of electricity consumption during the day, the 7.2Mpa 30℃ liquid carbon dioxide in the carbon dioxide storage tank is depressurized and gasified through the throttling pressure reducing valve and the third heat exchanger to form 7.2Mpa 35℃ gaseous carbon dioxide. The 7.2Mpa 35℃ gaseous carbon dioxide then passes through the fourth heat exchanger and is heated to 188℃ by using the heat in the hot end water storage tank. The cold energy is stored in the cold end water storage tank at the same time. 188℃ gaseous carbon dioxide is used to generate electricity through the carbon dioxide turbine, and finally forms 1.5Mpa gaseous carbon dioxide and returns to the second chamber of the constant pressure diaphragm air pressure tank underground; at the same time, in order to maintain a stable pressure of carbon dioxide in the second chamber, it is necessary to discharge the air in the first chamber of the constant pressure diaphragm air pressure tank, and keep the pressure values ​​of pressure sensor A103 and pressure sensor B104 at 1.5Mpa. The 1.5Mpa air in the first chamber is heated to 188℃ through the seventh heat exchanger and then generated by the first-stage air turbine to generate electricity. It is then heated to 188℃ again through the eighth heat exchanger and then generated by the second-stage air turbine to generate electricity. The generated cold energy is stored in the cold end water storage tank, and the normal pressure 0.1Mpa 56℃ air after energy release is directly discharged into the atmosphere.

[0021] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. An intensive mixed gas energy storage system, comprising a controller, a constant pressure diaphragm air pressure tank, and a carbon dioxide energy storage subsystem and an air compression energy release subsystem connected to the constant pressure diaphragm air pressure tank; the constant pressure diaphragm air pressure tank comprises a tank body, an air membrane is provided in the tank body, a first cavity in the tank body is used to store air, an air inlet and an air outlet of the first cavity are provided on the tank body, a second cavity in the air membrane is used to store carbon dioxide, and the air membrane is connected to an air inlet pipe and an air outlet pipe of the second cavity that pass through the tank body; characterized in that The constant pressure diaphragm air tank is also provided with a pressure sensor A for monitoring the first cavity, a pressure sensor B for monitoring the second cavity, and an air film pressure relief valve installed on the air film. The pressure sensor A, pressure sensor B and air film pressure relief valve are electrically connected to the controller respectively; The controller is used to control the running carbon dioxide energy storage subsystem or air compression energy release subsystem to stop running in an orderly manner when the pressure difference between the pressure value of the first chamber fed back by pressure sensor A and the pressure value of the second chamber fed back by pressure sensor B reaches a set threshold, and at the same time send a control signal for opening operation to the air film pressure relief valve; Used to send a closing control signal to the air film pressure relief valve when the pressure value of the first cavity fed back by the pressure sensor A is balanced with the pressure value of the second cavity fed back by the pressure sensor B; The controller adopts PLC, and the air film pressure relief valve adopts a normally closed self-locking solenoid valve.

2. The intensive mixed gas energy storage system according to claim 1, characterized in that: The energy storage component of the carbon dioxide energy storage subsystem includes the second cavity and the carbon dioxide compressor, the first heat exchanger, the second heat exchanger and the carbon dioxide storage tank; the energy release component of the carbon dioxide energy storage subsystem includes the carbon dioxide storage tank, the throttling pressure reducing valve, the third heat exchanger, the fourth heat exchanger and the carbon dioxide turbine and the second cavity; the heat exchange component of the carbon dioxide energy storage subsystem includes a hot-end water storage tank and a cold-end water storage tank, as well as a heat storage tank, a cold storage tank and a heat pump; the first heat exchanger and the hot-end water storage tank, the fourth heat exchanger and the cold-end water storage tank are connected by a first heat exchange circulation pipeline, and the second heat exchanger and the heat pump, the heat storage tank, the third heat exchanger and the cold storage tank are connected by a second heat exchange circulation pipeline.

3. The intensive mixed gas energy storage system according to claim 2, characterized in that: The compression component of the air compression energy release subsystem includes a first-stage air compressor, a fifth heat exchanger, a second-stage air compressor, a sixth heat exchanger and a first cavity; the energy release component of the air compression energy release subsystem includes the first cavity and a seventh heat exchanger, a first-stage air turbine, an eighth heat exchanger and a second-stage air turbine; the fifth heat exchanger, the sixth heat exchanger, the seventh heat exchanger and the eighth heat exchanger are respectively connected to heat exchange inlet and outlet pipes and are connected in parallel to the first heat exchange circulation pipeline.

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