Mixed gas energy storage system

Abstract

The mixed gas energy storage system comprises a constant-pressure diaphragm air pressure tank, a carbon dioxide energy storage subsystem and an air compression energy release subsystem, wherein the carbon dioxide energy storage subsystem and the air compression energy release subsystem are connected with the constant-pressure diaphragm air pressure tank; the number of the constant-pressure diaphragm air pressure tanks is at least two, and a first control valve and a second control valve are arranged on an air inlet pipe and an air outlet pipe, connected with the air compression energy release subsystem, of each constant-pressure diaphragm air pressure tank respectively. And a third control valve and a fourth control valve are respectively arranged on a carbon dioxide inlet pipe and a carbon dioxide outlet pipe, which are connected with the carbon dioxide energy storage subsystem, of each constant-pressure diaphragm air pressure tank. The mixed gas energy storage system has the advantages that at least two constant-pressure diaphragm gas pressure tanks are adopted, the first control valve, the second control valve, the third control valve and the fourth control valve of one constant-pressure diaphragm gas pressure tank can be independently closed for maintenance, and the other constant-pressure diaphragm gas pressure tank can continue to maintain normal operation of the mixed gas energy storage system.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage systems, in particular to a 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 the future energy system, especially in promoting the use of renewable energy and improving the stability of the power grid.

[0003] Carbon dioxide energy storage (CES) technology is a new type of physical energy storage technology based on compressed air energy storage (CAES) and Brayton power generation cycle. As a new technology, carbon dioxide energy storage uses a multi-stage compressor to convert atmospheric pressure gaseous carbon dioxide into high-pressure liquid carbon dioxide during the low electricity price period, and converts electrical energy into the form of carbon dioxide internal energy for storage; during the peak period of electricity consumption, the high-pressure liquid carbon dioxide is expanded and converted into atmospheric pressure gaseous carbon dioxide through a multi-stage expander to generate electricity, and finally realize the storage and release of electrical energy. However, the disadvantage of this system is that the equipment investment is huge. The whole system consists of low-pressure gas storage warehouse, high-pressure storage tank, compressor unit, turbine unit, heat exchange system and a large number of cold and heat storage tanks. In particular, the low-pressure gas storage warehouse uses atmospheric pressure to store carbon dioxide. Taking a 10MW carbon dioxide energy storage system as an example, its low-pressure gas storage warehouse will reach 1 million cubic meters, which will be a huge land cost in developed areas. To solve this problem, relevant personnel have developed a mixed gas energy storage system. The system uses a medium-pressure constant-pressure diaphragm air tank, which can reduce the occupied volume by dozens or even hundreds of times. One of the two working gases is air, which can be directly drawn from the atmosphere and discharged into the atmosphere in a straight line, eliminating a tank. However, the improved energy storage system only uses one constant-pressure diaphragm air tank, which needs to be stopped when the constant-pressure diaphragm air tank is overhauled, which needs to be improved. 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 a mixed gas energy storage system which occupies a small area and whose constant pressure diaphragm air pressure tank can be rotated for maintenance.

[0005] The technical solution adopted by the present utility model to solve the technical problem is as follows: A mixed gas energy storage system includes a constant pressure diaphragm gas tank and a carbon dioxide energy storage subsystem and an air compression and energy release subsystem connected to the constant pressure diaphragm gas tank; there are at least two constant pressure diaphragm gas tanks, and a first control valve and a second control valve are respectively provided on the air inlet pipe and the air outlet pipe connecting each constant pressure diaphragm gas tank to the air compression and energy release subsystem, and a third control valve and a fourth control valve are respectively provided on the carbon dioxide inlet pipe and the carbon dioxide outlet pipe connecting each constant pressure diaphragm gas tank to the carbon dioxide energy storage subsystem.

[0006] Compared with the related technology, the present utility model has the following advantages: At least two constant pressure diaphragm gas tanks are adopted, and the first control valve, the second control valve, the third control valve and the fourth control valve of a certain constant pressure diaphragm gas tank can be individually closed for maintenance, while the other constant pressure diaphragm gas tanks can continue to maintain the normal operation of the mixed gas energy storage system.

[0007] Preferably, it further includes a controller, a barometer provided on the tank body of each constant pressure diaphragm gas tank, and a pressure sensor provided in the air film of each constant pressure diaphragm gas tank. The first control valve, the second control valve, the third control valve, the fourth control valve and the barometer are respectively electrically connected to the controller, and the pressure sensor is wirelessly communicatively connected to the controller. A barometer for monitoring the air chamber air pressure is added to the tank body of the constant pressure diaphragm gas tank, and a pressure sensor for monitoring the air pressure in the air film is added in the air film. The barometer is electrically connected to the controller, and the pressure sensor is wirelessly communicatively connected to the controller. Under the control of the controller, in the coordinated operation of the carbon dioxide energy storage subsystem and the air compression and energy release subsystem, the constant pressure diaphragm gas tank operates under a constant pressure. When the pressure difference between the pressure value of the air chamber feedback by the barometer of a certain constant pressure diaphragm gas tank received by the controller and the pressure value of the air film feedback by the corresponding pressure sensor reaches the set threshold, the controller controls to close the first control valve, the second control valve, the third control valve and the fourth control valve of this constant pressure diaphragm gas tank, and sends an alarm signal to relevant personnel for timely maintenance, while the carbon dioxide energy storage subsystem and the air compression and energy release subsystem can continue to operate normally.

[0008] Preferably, a gas film relief valve is connected to the gas film of the constant-pressure diaphragm air pressure tank. The relief port of the gas film relief valve is communicated with the air cavity of the constant-pressure diaphragm air pressure tank where it is located, and the gas film relief valve is wirelessly communicatively connected to the controller. The controller sends a control signal for an opening operation to the gas film relief valve to discharge the carbon dioxide in the gas film into the air cavity, forming a pressure balance inside and outside the gas film to ensure the safety of the gas film. When the controller receives that the pressure value of the air cavity feedback by the barometer is balanced with the pressure value of the gas film feedback by the pressure sensor, the controller sends a control signal for a closing operation to the gas film relief valve; thereby avoiding that when a certain constant-pressure diaphragm air pressure tank body leaks, causing the pressure inside the gas film to be greater than the pressure outside the gas film, the gas film gradually expands to the limit and ruptures, resulting in further losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a connection schematic diagram of the mixed gas energy storage system of the present application (the controller is omitted). DETAILED DESCRIPTION OF THE EMBODIMENTS

[0010] First of all, those skilled in the art should understand that these embodiments are only used to explain the technical principles of the embodiments of the present application and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can adjust them as needed to adapt to specific application scenarios.

[0011] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0012] This preferred embodiment is a Figure 1 shown mixed gas energy storage system, including 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 and energy release subsystem connected to the constant-pressure diaphragm air pressure tank. Among them, the controller uses a PLC controller.

[0013] In this embodiment, there are two constant-pressure diaphragm gas pressure vessels, which are respectively marked as Tank A and Tank B. The gas storage pressure of the constant-pressure diaphragm gas pressure vessel is 1.5 Mpa, and it is buried underground to utilize the underground pressure to offset part of the expansion pressure of the constant-pressure diaphragm gas pressure vessel. Of course, when the thickness of the pressure vessel body increases, the gas storage pressure of the constant-pressure diaphragm gas pressure vessel can rise to 6 Mpa. The constant-pressure diaphragm gas pressure vessel includes a tank body. An air film is arranged inside the tank body. The air cavity outside the air film is used to store air, and the air film cavity inside the air film is used to store carbon dioxide. A first control valve and a second control valve are respectively arranged on the air inlet pipe and the air outlet pipe of the tank body. A carbon dioxide inlet pipe and a carbon dioxide outlet pipe that penetrate through the air film cavity of the tank body are connected to the air film. A third control valve and a fourth control valve are respectively arranged on the carbon dioxide inlet pipe and the carbon dioxide outlet pipe. The first control valve, the second control valve, the third control valve and the fourth control valve are all installed on the above-ground part of the pipeline. The second control valve on the air outlet pipe of Tank A is marked as Valve A2, the first control valve on the air inlet pipe of Tank A is marked as Valve A1, the third control valve on the carbon dioxide inlet pipe of Tank A is marked as Valve A4, and the fourth control valve on the carbon dioxide outlet pipe of Tank A is marked as Valve A3; the second control valve on the air outlet pipe of Tank B is marked as Valve B2, the first control valve on the air inlet pipe of Tank B is marked as Valve B1, the third control valve on the carbon dioxide inlet pipe of Tank B is marked as Valve B4, and the fourth control valve on the carbon dioxide outlet pipe of Tank B is marked as Valve B3.

[0014] As an improvement, a barometer for monitoring the air pressure in the air cavity is arranged on the constant-pressure diaphragm gas pressure vessel body, and a pressure sensor for monitoring the pressure inside the air film is arranged on the inner wall of the air film. The barometer, the first control valve, the second control valve, the third control valve and the fourth control valve are respectively electrically connected to the controller, and the pressure sensor is wirelessly communicatively connected to the controller. In the figure, the barometer of Tank A is marked as P A , the pressure sensor of Tank A is marked as Pressure Sensor A, and the barometer of Tank B is marked as P B , and the pressure sensor of Tank B is marked as Pressure Sensor B.

[0015] As an improvement, a membrane pressure relief valve is connected to the air film of the constant-pressure diaphragm gas pressure vessel. The pressure relief port of the membrane pressure relief valve is communicated with the air cavity of the constant-pressure diaphragm gas pressure vessel where it is located. The membrane pressure relief valve is wirelessly communicatively connected to the controller. The membrane pressure relief valve adopts a normally closed self-locking solenoid valve. When it is necessary to open the membrane pressure relief valve, the pressure difference inside and outside the air film of the constant-pressure diaphragm gas pressure vessel is balanced to avoid the rupture of the air film.

[0016] The thermal circulation pipeline of the carbon dioxide energy storage subsystem and the air compression and energy release subsystem is a conventional design and is not shown in the figure.

[0017] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A hybrid gas energy storage system, comprising a constant-pressure diaphragm gas tank and a carbon dioxide energy storage subsystem and an air compression and energy release subsystem connected to the constant-pressure diaphragm gas tank; characterized in that, There are at least two constant-pressure diaphragm gas pressure vessels. A first control valve and a second control valve are respectively provided on the air inlet pipe and the air outlet pipe connecting each constant-pressure diaphragm gas pressure vessel to the air compression and energy release subsystem. A third control valve and a fourth control valve are respectively provided on the carbon dioxide inlet pipe and the carbon dioxide outlet pipe connecting each constant-pressure diaphragm gas pressure vessel to the carbon dioxide energy storage subsystem.

2. The hybrid gas energy storage system according to claim 1, characterized in that, It further includes a controller, a barometer provided on the tank body of each constant-pressure diaphragm gas pressure vessel, and a pressure sensor provided in the air film of each constant-pressure diaphragm gas pressure vessel. The first control valve, the second control valve, the third control valve, the fourth control valve, and the barometer are respectively electrically connected to the controller, and the pressure sensor is wirelessly communicatively connected to the controller.

3. A hybrid gas energy storage system according to claim 2, characterized in that, A gas film pressure relief valve is connected to the gas film of each constant-pressure diaphragm gas pressure vessel. The pressure relief port of the gas film pressure relief valve is communicated with the air cavity of the constant-pressure diaphragm gas pressure vessel where it is located, and the gas film pressure relief valve is wirelessly communicatively connected to the controller.

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