Efficient compressed air energy storage system based on screw-slip sheet-centrifugal three-stage compression

Abstract

The invention relates to an efficient compressed air energy storage system based on screw-slip sheet-centrifugal three-stage compression. The efficient compressed air energy storage system comprises a gas pretreatment device, a gas compression device and an energy collecting and using device. The gas pretreatment device is used for treating gas and inputting the gas into the gas compression device; the gas compression device compresses gas step by step through a screw compressor, a sliding vane compressor and a centrifugal compressor which are connected in sequence and is used for completing first-stage compression, second-stage compression and third-stage compression of the gas. The energy collecting and using device comprises a pressure energy conversion device and an electric energy storage device, the pressure energy conversion device is used for converting pressure energy of the compressed gas into electric energy, and the electric energy is stored through the electric energy storage device. According to the compressors arranged according to the compression sequence, the high compression ratio can be achieved, energy can be reasonably utilized according to the characteristics of different compressors in the compression process of each stage, the compression efficiency is improved, and therefore the purpose of balancing the compression ratio and the efficiency is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of compressed air energy storage, and particularly to an efficient air compression energy storage system based on screw-vane-centrifugal three-stage compression. Background Art

[0002] Under the background of the global active promotion of the clean energy transformation, energy storage technology has become a key support in the energy field. Compressed air energy storage exhibits great application potential in aspects such as renewable energy grid connection and power grid load regulation due to its significant advantages of large-capacity energy storage, long service life, and environmental friendliness. However, there are still a series of problems to be solved urgently in the current compressed air energy storage regarding the treatment of ambient air and the adopted compression system. Traditional compression systems mostly adopt multi-stage compression methods, which result in extremely complex equipment structures, not only occupying a large amount of space but also significantly increasing the construction cost. In addition, a large amount of heat energy generated during the compression process, if not properly recovered and utilized, will not only reduce the energy utilization efficiency but also may affect the stable operation of the equipment. More critically, the existing compression systems are difficult to achieve an ideal balance between the compression ratio and efficiency, which greatly restricts the further improvement of the overall performance of the compressed air energy storage system. Summary of the Invention

[0003] To solve the problems existing in the above-mentioned prior art, the present invention provides an efficient air compression energy storage system based on screw-vane-centrifugal three-stage compression, which specifically includes the following technical solutions: An efficient air compression energy storage system based on screw-vane-centrifugal three-stage compression includes a gas pretreatment device, a gas compression device, and an energy collection and utilization device; the gas pretreatment device is used to process the gas and input the processed gas into the gas compression device; the process of processing the gas includes at least one of filtration, mixing, rectification, dehumidification, and preheating; the gas compression device is used to compress the processed gas step by step, including a screw compressor, a vane compressor, and a centrifugal compressor sequentially connected by pipelines, which are respectively used to complete the first-stage compression, the second-stage compression, and the third-stage compression of the gas; the energy collection and utilization device includes a pressure energy conversion device and an electric energy storage device, and the pressure energy conversion device is used to convert the pressure energy of the compressed gas into electric energy and store the electric energy through the electric energy storage device.

[0004] Further, the gas pretreatment device includes a gas mixing chamber and a stirring mechanism arranged inside the gas mixing chamber, which is used to complete the mixing process of the gas; the gas mixing chamber is provided with an intake pipeline and an outlet pipeline, which are respectively used for the inhalation and discharge of the gas; the stirring mechanism includes a motor, a circular base fixedly installed on the output shaft of the motor, and blades circumferentially and equally spacedly installed on the circular base, and the motor drives the blades to rotate and can generate eddy currents in the gas mixing chamber.

[0005] Furthermore, the gas pretreatment device further includes a flow guide plate and a spoiler column disposed inside the gas mixing chamber; a plurality of the flow guide plates are provided, one end of which is fixedly disposed on the inner wall of the gas mixing chamber, the other end points to the axis of the gas mixing chamber, and is arranged in a spiral shape along the axial direction of the gas mixing chamber; a plurality of the spoiler columns are provided, which are disposed on the bottom surface and the top surface of the inner wall of the gas mixing chamber and are perpendicular to the inner wall of the gas mixing chamber.

[0006] Furthermore, the gas pretreatment device includes a rectifying tube for rectifying the gas; a flow guide vane is disposed inside the rectifying tube, the flow guide vane has a smooth surface and is parallel to the axial direction of the rectifying tube; the length of the flow guide vane is 0.5 - 1.0 times the diameter of the rectifying tube.

[0007] Furthermore, the gas pretreatment device includes an adsorption dryer for dehumidifying the gas and controlling the moisture content in the gas within the range of 0.01% - 0.1%.

[0008] Furthermore, the gas pretreatment device includes a first plate heat exchanger; the first plate heat exchanger is disposed between the gas rectifying operation and the gas dehumidifying operation for preheating the gas.

[0009] Furthermore, the gas compression device further includes an intake air treatment mechanism for filtering and noise reduction of the gas input into the screw compressor, including a fiber filter, a reactive muffler, and an absorptive muffler connected in sequence through a pipeline.

[0010] Furthermore, the gas compression device further includes a shell - and - tube cooler and a gas - liquid separator, and the shell - and - tube cooler and the gas - liquid separator are respectively disposed between the screw compressor and the sliding vane compressor, and between the sliding vane compressor and the centrifugal compressor for cooling the compressed gas to the designed temperature and drying it.

[0011] Furthermore, the gas compression device further includes an exhaust buffer tank and a gas storage tank; the exhaust buffer tank is connected to the centrifugal compressor through a pipeline for evenly distributing the compressed gas inside it and reducing the pressure pulsation; the gas storage tank is connected to the exhaust buffer tank through a pipeline for storing the compressed gas.

[0012] Furthermore, the pressure energy conversion device includes a turboexpander and a generator; the turboexpander is connected to the gas storage tank through a pipeline, and the compressed gas in the gas storage tank drives the turboexpander to operate, converting the pressure energy into mechanical energy; the turboexpander is connected to the generator through a coupling, and the turboexpander drives the generator to operate, converting the mechanical energy into electrical energy.

[0013] Further, the energy collection device further includes a heat-conducting oil circulation system, which includes a second plate heat exchanger, a shell-and-tube heat exchanger, a heat-conducting oil pipeline, a heat-conducting oil pump, a PLC, and a heat storage tank; the second plate heat exchanger is arranged at the screw compressor, and the shell-and-tube heat exchanger is arranged at the sliding vane compressor and the centrifugal compressor; the heat storage tank is connected to the second plate heat exchanger and the shell-and-tube heat exchanger respectively through the heat-conducting oil pipeline to form a heat-conducting oil circulation loop; the heat-conducting oil pump is installed on the heat-conducting oil pipeline and is connected to the PLC control host to control the operation of the heat-conducting oil pump through the PLC.

[0014] Further, the heat-conducting oil circulation system further includes a temperature sensor and a regulating valve installed on the heat-conducting oil pipeline; the PLC uses a Siemens S7-300 type PLC, and the PLC is connected to the temperature sensor and the regulating valve, and is used to receive the data transmitted by the temperature sensor and control the operation of the heat-conducting oil pump and the regulating valve according to the temperature data transmitted by the temperature sensor.

[0015] Further, the gas is a mixed gas of fresh air and low-pressure air.

[0016] Further, the compressed air energy storage system further includes an intelligent control network working system, which includes a data acquisition device, a network transmission device, a central control device, and a remote monitoring and management device; the data acquisition device includes a sensor mechanism and a data acquisition terminal; the sensor mechanism includes at least one of a vibration sensor, a gas composition sensor, and a flow sensor; the vibration sensor is respectively arranged at the rotor of the screw air compressor, the sliding vane of the sliding vane compressor, and the impeller of the centrifugal compressor to monitor the vibration state of the equipment in real time; the gas composition sensor is arranged inside the gas storage device of the compressed air energy storage system to monitor the change of the gas composition in real time; the flow sensor is distributed inside each pipeline of the compressed air energy storage system to monitor the gas flow at different pipeline positions; the data acquisition terminal is used to summarize the monitoring data collected by the sensor mechanism and convert it into a digital signal; the network transmission device includes an industrial Ethernet mechanism, and the central control device includes an industrial control computer; the industrial Ethernet mechanism is connected to the data acquisition terminal and the industrial control computer, and forms a redundant network topology structure through optical fibers and switches to monitor and control the gas pretreatment device, the gas compression device, and the energy collection device of the compressed air energy storage system.

[0017] Based on the above technical solutions, the present invention has the following beneficial effects: 1. The setting of the mixed gas can improve the composition uniformity of the gas to be compressed, reduce the working pressure of the equipment during the subsequent gas compression process, relieve the compressor load, ensure the stable and efficient progress of the subsequent air compression process, improve the overall compression efficiency, reduce problems such as local overheating and uneven pressure caused by gas composition differences, thereby improving the reliability of the system described in the present invention and extending the service life of the system.

[0018] 2. The stirring mechanism arranged inside the gas mixing chamber can generate strong vortices through the high-speed rotation of the blades, realizing gas mixing fully and quickly; the guide plate can change the flow direction of the gas, making the gas form a spiral flow trajectory, and the gases interpenetrate and collide with each other during the spiral movement, increasing the contact area between the gases and promoting the mixing of different gases; the spoiler columns change the originally relatively regular air flow streamline, generating turbulence and vortices, and these turbulent air flows interact with the surrounding gases, further disrupting the flow direction of the gases and increasing the degree of gas mixing.

[0019] 3. Using a heat exchanger to preheat the gas can reduce the density of the gas, reduce the power consumption during the compression process of the compressor, and improve the compression efficiency; avoid equipment damage caused by too low temperature of the gas during the compression process; after gases at different temperatures are mixed, preheating can make the temperature distribution of the gas more uniform, reduce problems such as unstable gas flow caused by temperature differences, and improve the operation stability of the entire system.

[0020] 4. The intake air treatment mechanism performs fine filtration and noise reduction on the mixed gas, which can reduce the wear of the internal components of the compressor by the gas and reduce the resistance of the equipment operation; the noise reduction treatment can reduce the risks of equipment vibration and resonance caused by noise, contribute to maintaining the stable operation state of the equipment, reduce the probability of failures, thereby improving the equipment operation efficiency, ensuring the stable operation of the equipment, and improving the gas compression quality.

[0021] 5. The compression mechanism arranged in the order of screw compressor → sliding vane compressor → centrifugal compressor can not only achieve a high compression ratio, but also rationally utilize energy according to the characteristics of different compressors during each stage of compression, improve the compression efficiency, so as to achieve the purpose of balancing the compression ratio and efficiency.

[0022] 6. The cooling mechanisms arranged between the screw compressor and the sliding vane compressor, and between the sliding vane compressor and the centrifugal compressor can prevent high-temperature gas from damaging the subsequent compression equipment, ensure the compression efficiency and extend the service life of the equipment. Brief Description of the Drawings

[0023] Figure 1 : Schematic Structural Diagram of the Gas Pretreatment Device (1); Figure 2: Schematic diagram of the layout of the flow deflector in the gas mixing chamber; Figure 3 : Schematic diagram of the structure of the gas pretreatment device (2); Figure 4 : Schematic diagram of the structures of the first-stage compression and second-stage compression processes of the gas compression device; Figure 5 : Schematic diagram of the structure of the third-stage compression process of the gas compression device; Figure 6 : Schematic diagram of the structure of the heat-conducting oil circulation system; Figure 7 : Schematic diagram of the structure of the pressure energy conversion device.

[0024] Symbol Explanation 101 - Gas mixing chamber, 102 - Intake pipeline, 103 - Bag filter, 104 - Motor, 105 - Blade, 106 - Flow deflector, 107 - Turbulence post, 108 - Rectifier tube, 109 - Flow guiding vane, 110 - Adsorption dryer, 111 - First plate heat exchanger; 201 - Fiber filter, 202 - Resistance muffler, 203 - Resistive muffler, 204 - Screw compressor, 205 - Sliding vane compressor, 206 - Centrifugal compressor, 207 - Shell-and-tube cooler, 208 - First gas-liquid separator, 209 - Second gas-liquid separator, 210 - Suction and discharge valve, 211 - Exhaust buffer tank; 301 - Second plate heat exchanger, 302 - Shell-and-tube heat exchanger, 303 - Heat-conducting oil pipeline, 304 - Heat-conducting oil pump, 305 - Heat storage tank, 306 - Control valve, 307 - Heat distribution pipeline; 401 - Expander, 402 - Generator, 403 - Roots-type low-pressure gas compressor. Detailed Embodiment

[0025] It should be noted that: 1. In the description and claims, certain terms are used to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. Therefore, this description and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of components as the criterion for distinction. Unless otherwise defined, the technical terms or scientific terms used in this disclosure should have the ordinary meaning understood by those of ordinary skill in the art to which this disclosure belongs.

[0026] 2. Connect the schematic diagrams recorded in Attachments Figure 1 , 3 , 4, 5, 7 in sequence, which is the process of air compression and use in the technical solution recorded in this invention.

[0027] The following will describe the present invention in detail by way of embodiments in conjunction with the attached Figure 1 drawings Figure 7 to the attached

[0028] An efficient compressed air energy storage system based on screw - sliding vane - centrifugal three - stage compression includes a gas pretreatment device, a gas compression device, an energy utilization device, and an intelligent control network working system.

[0029] The gas pretreatment device is used to process the gas to be compressed, and the processing methods include but are not limited to mixing, rectification, dehumidification, and preheating.

[0030] The gas to be compressed is composed of two parts mixed together. One is the filtered ambient air, and the other is the compressed low - pressure gas. The ambient air can be filtered by a bag filter 103 to remove large - particle impurities such as broken blades and dust in the ambient air; the low - pressure gas can be obtained by processing with a Roots - type low - pressure gas compressor 403, and preferably the low - pressure gas is set in the range of 9800 to 98000 Pa.

[0031] The ambient air and the low - pressure gas are fully mixed. By discharging the energy in the low - pressure gas, the energy utilization rate can be improved, and at the same time, fresh air is supplemented, which can maintain the stability of the gas supply of the system. Therefore, setting the mixed gas can improve the composition uniformity of the gas to be compressed, reduce the working pressure of the equipment in the subsequent gas compression process, reduce the compressor load, ensure the stable and efficient progress of the subsequent air compression process, improve the overall compression efficiency, and reduce problems such as local overheating and pressure unevenness caused by gas composition differences, thereby improving the reliability of the system operation and extending the service life of the system.

[0032] The gas pretreatment device includes a gas mixing chamber 101, a rectifying tube 108, a dryer 110, and a heat exchanger, wherein a stirring mechanism and a flow - guiding mechanism are arranged in the gas mixing chamber.

[0033] The main structure of the gas mixing chamber 101 is cylindrical and is made of high - strength and corrosion - resistant alloy steel. At least two intake pipes 102 are arranged at the intake end of the gas mixing chamber 101, which are respectively connected to the bag filter 103 and the Roots - type low - pressure gas compressor 403, and the filtered and compressed air enters the gas mixing chamber 101 through the intake pipes 102. Among them, the ambient air is pumped into the gas mixing chamber by a Roots blower, and the low - pressure gas is pumped into the gas mixing chamber by the Roots - type low - pressure gas compressor 403.

[0034] The stirring mechanism is arranged inside the gas mixing chamber 101 and includes a motor 104, a circular base fixedly installed on the output shaft of the motor, and blades 105 circumferentially and equidistantly installed on the circular base. After the motor 104 is started, the circular base rotates synchronously with the output shaft of the motor, driving the blades 105 to rotate, generating a strong vortex inside the gas mixing chamber 101, and fully and quickly realizing gas mixing. This embodiment does not limit the specific position of the stirring mechanism inside the gas mixing chamber 101. In actual use, the installation position can be selected by adjusting the position multiple times to obtain a better stirring effect.

[0035] The flow guiding mechanism is arranged inside the gas mixing chamber 101 and is used to further enhance the mixing effect of the gas inside the gas mixing chamber 101, and includes a flow guiding plate 106 and a flow disturbing column 107.

[0036] A plurality of flow guiding plates 106 are provided. One end is fixed to the inner wall of the gas mixing chamber 101 by bolts or welding, etc., and the other end points to the axis of the gas mixing chamber 101 and extends from the air inlet end to the air outlet end in the form of a spiral along the axial direction of the gas mixing chamber 101. When the gas enters the gas mixing chamber 101, the flow guiding plate 106 changes the flow direction of the gas, causing the gas to form a spiral flow trajectory, interpenetrating and colliding with each other during the spiral movement, increasing the contact area between the gases, and promoting the mixing of different gases. At the same time, the spiral flow also prolongs the residence time of the gas inside the gas mixing chamber 101, enabling the gas to have more sufficient time for mixing and improving the mixing effect.

[0037] The flow guiding plate 106 is preferably a rectangular plate with a thickness of 5 - 10 mm and a width of 10 - 20 cm. The specific dimensions can also be adjusted according to the size of the gas mixing chamber 101, the gas flow rate, and the mixing requirements, which will not be elaborated in this embodiment.

[0038] The overall structure of the spoiler post 107 is cylindrical, and the diameter is set to 3-5cm, and the height is set to 1 / 5-1 / 3 of the height of the gas mixing chamber 101, which can effectively disrupt the gas streamlines and will not cause excessive obstruction to the gas flow. Obviously, the actual size of the spoiler post 107 can also be determined according to the size of the gas mixing chamber 101 and the gas working condition. The technician can determine it by calculating the parameters such as the Reynolds number of the gas in the gas mixing chamber 101 during implementation, so as to ensure that the airflow can be effectively disturbed under different working conditions. The present embodiment will not repeat them. The spoiler post 107 is set to multiple, distributed on the bottom and top surfaces of the inner walls of the gas mixing chamber 101, and is vertical to the inner wall of the gas mixing chamber 101. When the gas flows through the spoiler post 107, the spoiler post 107 changes the originally relatively regular airflow streamlines, produces turbulence and vortex, and these turbulent airflows interact with the surrounding gas, further disrupt the flow direction of the gas, and increase the mixing degree between the gases. The presence of the spoiler column 107 breaks the laminar flow state that may be formed by the gas, and promotes the gas to be fully mixed in all directions, thereby improving the mixing effect.

[0039] In order to obtain a better air flow disturbance effect and to disturb the gas flow comprehensively and evenly, the spoiler columns 107 are evenly arranged in an array in the gas mixing chamber 101, but densely distributed at the inlet end of the gas mixing chamber 101 to enhance the disturbance effect on the initial incoming gas; sparsely distributed at the outlet end to avoid too much unnecessary obstruction to the mixed gas that is about to flow out. Dense distribution and sparse distribution are relative to uniform arrangement, specifically: array arrangement, the row and column spacing of the spoiler columns 107 is determined according to the flow rate and mixing requirements of the gas, generally set to 10-20cm; dense distribution is generally set to 5-15cm; sparse distribution is generally set to 15-25cm.

[0040] The guide plate 106 and the spoiler column 107 are made of the same material as the gas mixing chamber 101 to ensure durability in a complex gas environment. The guide plate 106 and the spoiler column 107 cooperate with each other. The guide plate 106 guides the gas to perform macroscopic spiral flow to create basic conditions for mixing; the spoiler column 107 further enhances the disturbance and mixing of the gas at the microscopic level. The two work together to achieve efficient mixing of the gas in the gas mixing chamber 101.

[0041] The gas outlet of the gas mixing chamber 101 is connected to the rectifying tube 108, and a guide vane 109 is arranged inside the rectifying tube 108. The guide vane 109 is a straight plate with a smooth surface to reduce the resistance of gas flow. According to fluid mechanics calculations and multiple experimental verifications, the length of the guide vane 109 is set to 0.5-1.0 times the diameter of the rectifying tube 108 in this embodiment, and the thickness is set to 3-8 mm.

[0042] The flow guiding vane 109 can be installed at any position inside the rectifying tube 108, but it is preferably installed at the pipe orifice. When installing the flow guiding vane 109, it should be ensured that the vane is parallel to the axis of the rectifying tube 108 to make the gas flow more smoothly and reduce the influence of airflow pulsation on subsequent equipment; it should also be ensured that the spacing between each vane is uniform to ensure uniform rectification effect on the gas. During installation, it is necessary to ensure that the vane is firmly connected to the pipeline to prevent shaking or falling off during gas flow, which may affect the rectification effect or even damage subsequent equipment.

[0043] The rectifying tube 108 is connected to the adsorption dryer 110 through a pipeline for removing moisture in the gas. The rectified gas usually contains 5% to 10% moisture. The moisture will act with the heat generated during the compression process to form a corrosive environment, affecting the equipment life; at the same time, the phase change of water vapor will consume energy and reduce the compression efficiency; moreover, the moisture will freeze and block the pipeline at low temperature, so it is necessary to remove and control the moisture content in the gas within the range of 0.01% - 0.1%.

[0044] Furthermore, a first plate heat exchanger 111 is also provided between the rectifying tube 108 and the adsorption dryer 110. The first plate heat exchanger 111 is connected to the rectifying tube 108 and the adsorption dryer 110 respectively through pipelines for preheating the mixed gas. The first plate heat exchanger 111 is connected to the pipeline through a flange. The first plate heat exchanger 111 is provided with multiple channels. The mixed gas channel is connected to the pipelines between the rectifying tube 108 and the adsorption dryer 110, and the other channel is used for introducing a heat medium. As an existing device, in this embodiment, the gas is preheated by this device. Since no structural and principle improvements are made to it, the structure and working principle of this device will not be elaborated in this embodiment.

[0045] Preheating the gas using a heat exchanger has the following beneficial effects: ① Preheating can reduce the density of the gas. According to the ideal gas state equation, at a certain pressure, when the temperature rises, the gas volume expands and the density decreases. When the compressor compresses the same mass of gas, the work done is correspondingly reduced. Therefore, it can reduce the power consumption of the compressor during the compression process and improve the compression efficiency.

[0046] ② Avoid equipment damage caused by too low temperature during gas compression. In a low-temperature environment, the heat generated during gas compression may not be dissipated in time, easily causing local overheating and affecting the service life of the equipment. The temperature of the preheated gas changes relatively smoothly during compression, which can reduce the damage of this thermal stress to the equipment.

[0047] ③Stabilize the properties of the mixed gas, which is helpful for subsequent compression and processing. After gases at different temperatures are mixed, preheating can make the temperature distribution of the gas more uniform, reduce problems such as unstable gas flow caused by temperature differences, and improve the operating stability of the entire system.

[0048] The setting of the gas preheating temperature needs to consider multiple factors, such as the material and performance parameters of subsequent compressors at all levels, and the composition of the mixed gas. Moreover, the preheating temperature should be lower than the maximum intake temperature that the subsequent compressor can withstand, and it is necessary to ensure that no chemical reaction or change in physical properties occurs to the gas at this temperature, which may affect the compression and energy storage processes. To better enhance the above beneficial effects, in this embodiment, based on multiple experiments and simulation analyses, the temperature of the preheated gas is preferably set to 30 - 50 °C.

[0049] The gas compression device includes an intake air treatment mechanism, a compression mechanism, a cooling mechanism, a gas-liquid separator, and a gas storage tank.

[0050] The intake air treatment mechanism includes a fiber filter 201, a reactive muffler 202, and an absorptive muffler 203. The fiber filter 201 is connected to the adsorption dryer 110 through a pipeline, and is successively connected to the reactive muffler 202 and the absorptive muffler 203 through pipelines. The preheated mixed gas undergoes fine filtration and noise reduction through the intake air treatment mechanism. Performing fine filtration and noise reduction on the preheated and leveled gas can make the gas input to the compression mechanism have the following properties: the gas cleanliness reaches the standard of solid particle size not exceeding 3 μm and dust content lower than 1 mg / m³ specified in ISO 8573.1 - 2010; the sound pressure level of low-frequency noise (in the frequency band of 50 - 500 Hz) is reduced to below 40 dB(A); the sound pressure level of high-frequency noise (in the frequency band of 1000 - 10000 Hz) is reduced to below 50 dB(A). Performing fine filtration and noise reduction on the mixed gas can reduce the wear of the internal components of the compressor by the gas and reduce the resistance of equipment operation; noise reduction can reduce the risks of equipment vibration and resonance caused by noise, help maintain a stable operating state of the equipment, reduce the probability of failures, thereby improving the equipment operation efficiency, ensuring the stable operation of the equipment, and enhancing the gas compression quality. For workers, working in a noisy environment for a long time will seriously affect work efficiency and pose work hazards. Therefore, noise reduction is a necessary improvement.

[0051] The compression mechanism includes a screw compressor 204, a sliding vane compressor 205, and a centrifugal compressor 206, which are respectively used for the first-stage compression, second-stage compression, and third-stage compression of the gas, and achieve the balance between the compression ratio and efficiency through the method of gradually increasing pressure in stages.

[0052] First-stage compression: The screw compressor 204 serves as the first-stage compression equipment. Through the meshing and disengagement of the male and female rotors, it realizes the intake, compression, and discharge of air. Since the screw compressor 204 has a high working efficiency at a relatively low pressure ratio, it can preliminarily compress the gas with relatively low energy consumption, providing stable starting conditions for the entire compression process and laying a foundation for the subsequent second-stage and third-stage compressions.

[0053] Second-stage compression: After the first-stage compression, both the temperature and pressure of the gas increase. The sliding vane compressor 205 has good performance in the medium-pressure range. Through the cooperation of the rotor and the sliding vane, it divides the space in the cylinder into multiple working chambers with variable volumes to realize the further compression of the gas. In the second-stage compression stage, the sliding vane compressor 205 utilizes its good sealing and compression performance to further increase the gas pressure. At the same time, through its own lubrication and cooling system, it takes away the heat generated during the compression process to ensure the normal operation of the compressor and also provides suitable gas conditions for the subsequent third-stage compression.

[0054] Third-stage compression: After the first two-stage compressions, the gas pressure is already relatively high, and it enters the centrifugal compressor 206 for the third-stage compression. The centrifugal compressor 206 has a high efficiency under a high pressure ratio and can raise the gas pressure to a higher level. Its impeller does work on the gas when rotating at high speed, enabling the gas to obtain kinetic energy, and the volute and diffuser convert the kinetic energy into pressure energy.

[0055] Through the step-by-step pressurization of the above three-stage compressions, not only can a high compression ratio be achieved, but also energy can be reasonably utilized according to the characteristics of different compressors during each stage of compression to improve the compression efficiency, thereby achieving the purpose of balancing the compression ratio and efficiency. The compression mechanism described in this embodiment is installed in the order of screw compressor → sliding vane compressor → centrifugal compressor, and the installation order cannot be adjusted. The reasons are as follows: ① Pressure adaptability: The screw compressor 204 is suitable for starting the compression process at a relatively low pressure. It has relatively low requirements for the intake pressure and can stably compress ambient air or low-pressure gas initially. The sliding vane compressor 205 is applicable to the medium-pressure range. After the screw compressor 204 increases the pressure, the sliding vane compressor 205 can better adapt and further increase the pressure. The centrifugal compressor 206 can exert its high-efficiency compression advantage in a high-pressure environment. After reaching a relatively high pressure through the first two-stage compressions, the centrifugal compressor 206 performs the final high-pressure compression to achieve the efficient operation of the entire compression process. If the order is changed, for example, if the centrifugal compressor 206 is used first, due to its certain requirements for the intake pressure and flow rate, it may not work properly or have extremely low efficiency under low-pressure intake conditions.

[0056] ② Temperature control: Heat is generated during the compression of gas by each stage of the compressor, and different compressors have different heat dissipation and temperature adaptation capabilities. The heat generated by the screw compressor 204 during the first-stage compression is relatively small. After intermediate cooling, it is suitable to enter the sliding vane compressor 205, which is more sensitive to temperature, for the second-stage compression. The sliding vane compressor 205 can effectively remove heat through its own lubrication and cooling system, providing suitable temperature conditions for the gas entering the centrifugal compressor 206. Although the centrifugal compressor 206 can also operate under high temperature and high pressure, too high an intake temperature will affect its efficiency and performance. Therefore, the existing sequence helps to reasonably control the gas temperature and ensure the normal operation of each stage of the compressor.

[0057] ③ Complementary equipment characteristics: The screw compressor 204 has the characteristics of simple structure and stable operation, and can provide stable initial compression; the sliding vane compressor 205 has good sealing performance and can further increase the compression ratio in the medium-pressure stage; the centrifugal compressor 206 has high efficiency under high pressure ratio and can achieve the final high-pressure output. This sequence gives full play to the advantages of each stage of the compressor, complements each other, and jointly realizes an efficient three-stage compression process. If the sequence is adjusted, the advantages of each compressor may not be fully utilized, resulting in a decline in the performance of the entire compression system.

[0058] At the connection pipes between the screw compressor 204 and the sliding vane compressor 205, and between the sliding vane compressor 205 and the centrifugal compressor 206, suction and exhaust valves are provided to avoid the negative pressure hazards brought by the air flow to the compressor.

[0059] The cooling mechanism includes shell-and-tube coolers, which are respectively arranged between the screw compressor 204 and the sliding vane compressor 205, and between the sliding vane compressor 205 and the centrifugal compressor 206, to reduce the temperature of the compressed gas discharged from the screw compressor 204 and the sliding vane compressor 205 to the designed temperature.

[0060] Under normal operating conditions, the temperature of the gas compressed by the screw compressor 204 is usually between 80 - 120°C, and the suitable temperature for entering the sliding vane compressor 205 is 40 - 60°C; the temperature of the gas compressed by the sliding vane compressor 205 is usually between 100 - 150°C, and the suitable temperature for entering the centrifugal compressor 206 is 40 - 50°C. Setting up a cooling mechanism can prevent high-temperature gas from damaging subsequent compression equipment, ensure compression efficiency and extend the service life of the equipment. Moreover, the main design purpose of the heat exchanger described above is to achieve heat exchange and recover heat, and its cooling effect is limited by various factors; while the cooling mechanism uses cooling media such as circulating water and strengthens heat transfer through a special structure, with a better cooling effect. Therefore, in the case of high gas temperature and the need for rapid cooling, the heat exchanger is difficult to quickly reduce the gas temperature to the appropriate range, and thus it is difficult to replace the role of the cooling mechanism and cannot achieve both efficient cooling and ideal heat recovery simultaneously.

[0061] The gas-liquid separator includes a first gas-liquid separator 208 and a second gas-liquid separator 209. The gas-liquid separator adopts the centrifugal gas-liquid separation principle. When the compressed air containing condensed water enters the gas-liquid separator, under the action of centrifugal force, water and impurities are thrown towards the inner wall of the separator, then flow down along the wall surface and are discharged from the drain port at the bottom, ensuring that the gas entering the next-stage compressor is dry.

[0062] The first gas-liquid separator 208 is arranged between the screw compressor 204 and the sliding vane compressor 205, and is connected to the screw compressor 204 and the sliding vane compressor 205 through pipelines respectively. It is used to remove water and impurities from the compressed gas output by the screw compressor 204 and input the processed dry gas into the sliding vane compressor 205; The second gas-liquid separator 209 is arranged between the sliding vane compressor 205 and the centrifugal compressor 206, and is connected to the sliding vane compressor 205 and the centrifugal compressor 206 through pipelines respectively. It is used to remove water and impurities from the compressed gas output by the sliding vane compressor 205 and input the processed dry gas into the centrifugal compressor 206.

[0063] The compressed gas after the above three-stage compression and gas-liquid separation treatment has the properties of high pressure, high temperature, and cleanliness, meeting the energy storage requirements and being stored in the gas storage tank. Among them: High pressure: From the initial pressurization of the screw compressor 204, to the further pressure increase of the sliding vane compressor 205, and then to the efficient compression of the centrifugal compressor 206 at a high pressure ratio, the gas pressure is greatly increased, which can meet the energy storage requirements. In the compressed air energy storage system, the high-pressure gas is stored, and when it is released subsequently, it can drive the turbine to generate electricity, realizing the storage and conversion of energy.

[0064] High temperature: During the three-stage compression process, each stage of the compressor does work on the gas, converting mechanical energy into internal energy, which causes the gas temperature to continue to rise. The centrifugal compressor 206 has a large compression ratio and does a lot of work, further increasing the gas temperature. When discharged, the gas temperature is estimated to be around 150 - 200 °C.

[0065] Cleanliness: Before the mixed gas enters the compression system, it undergoes multiple filtrations. The bag filter 103 in the intake pretreatment device filters out larger impurities such as broken leaves and dust, and the fiber filter filters out fine particles, making the gas entering the centrifugal compressor relatively clean. After three-stage compression, the impurities in the gas are further compressed and their relative content decreases. The clean gas helps to ensure the stability of the subsequent energy storage and energy conversion processes, reducing wear and corrosion of the equipment.

[0066] Preferably, the gas compression device further includes an exhaust buffer tank 211 and a muffler. The exhaust buffer tank 211 is connected to the centrifugal compressor 206 through a pipeline, and is used to stabilize the pressure of the high-pressure air discharged from the centrifugal compressor 206, reducing pressure fluctuations. A baffle plate is provided inside the exhaust buffer tank 211 to make the incoming high-pressure air evenly distributed in the tank, further reducing pressure pulsation. The muffler is connected to the exhaust buffer tank 211 and the gas storage tank through pipelines respectively, and includes a reactive muffler 202 and a resistive muffler 203. The reactive muffler 202 reduces the low-frequency components of the exhaust noise by changing the cross-sectional area and shape of the air flow channel, and the resistive muffler 203 uses sound-absorbing materials to absorb high-frequency noise, effectively reducing the noise pollution during the exhaust process and enabling the device to meet environmental protection requirements.

[0067] The energy utilization device includes a heat transfer oil circulation system and a pressure energy recovery and utilization mechanism.

[0068] The heat transfer oil circulation system includes a heat exchanger array, a heat transfer oil pipeline 303, a heat transfer oil pump 304, a control system, and a heat storage tank 305.

[0069] The heat exchanger array includes a second plate heat exchanger 301 and a shell-and-tube heat exchanger 302. At the first-stage screw compressor, the second plate heat exchanger 301 is used because of its compact structure, which is suitable for the relatively low temperature and pressure environment after the first-stage compression and can effectively recover the compression heat. The second-stage vane compressor and the third-stage centrifugal compressor use the shell-and-tube heat exchanger 302 to adapt to higher temperatures and pressures. The second plate heat exchanger 301 and the shell-and-tube heat exchanger 302 are connected into a closed circulation loop through the heat transfer oil pipeline 303 to ensure that the heat transfer oil can continuously circulate in the heat transfer oil circulation system.

[0070] The heat transfer oil pipeline 303 connects the second plate heat exchanger 301, the shell-and-tube heat exchanger 302, and the heat storage tank 305 in an orderly manner, specifically as follows: Starting from the heat storage tank 305, the heat-conducting oil first flows into the second plate heat exchanger at the first-stage screw compressor, where it absorbs the heat generated by the compression of the gas by the screw compressor 204 and the temperature rises; Subsequently, the heated heat-conducting oil enters the shell-and-tube heat exchanger at the second-stage sliding vane compressor along the pipeline, and continues to absorb the heat released by the compression of the gas by the sliding vane compressor 205, further increasing the temperature; Then, the heat-conducting oil flows into the shell-and-tube heat exchanger 302 at the third-stage centrifugal compressor, absorbing the heat generated by the centrifugal compressor 206; After three-stage compression heat recovery, the heat-conducting oil with a higher temperature flows back to the heat storage tank 305 for storage.

[0071] During the connection of the heat-conducting oil pipeline 303, ensure that the inlets and outlets of each heat exchanger are closely connected to the heat-conducting oil pipeline 303, and the pipe diameter of the pipeline is reasonably adjusted according to the flow rate and pressure of the heat-conducting oil to ensure that the heat-conducting oil can flow smoothly in the pipeline and reduce the resistance loss.

[0072] The heat-conducting oil pump 304 is installed on the heat-conducting oil pipeline 303, and under the control of the control system, it adjusts its own output power and flow rate to control the flow of the heat-conducting oil between the second plate heat exchanger 301 and the shell-and-tube heat exchanger 302. The control system also includes a temperature sensor and a regulating valve 306 installed on the heat-conducting oil pipeline 303 to achieve precise control of the flow of the heat-conducting oil. The control system selects the S7-300 type PLC produced by Siemens as the control host. This control host is of modular structure and is composed of modules such as a PLC rack, a CPU, digital I / O, analog input, power supply, and communication. The PLC automation control system reasonably schedules the heat-conducting oil pump 304 and the regulating valve 306 according to the temperature data transmitted by the temperature sensor. As a commonly used device, this PLC control host is widely used in fields such as coal mine mining and water conservancy control. In this embodiment, its structure and working principle are not improved, so the corresponding structure and working principle and other contents are not described in detail. The operation process is briefly described as follows: When the temperature sensor detects a change in the temperature of the heat-conducting oil at the inlet or outlet of a certain heat exchanger, the signal is transmitted to the control system, and the control system adjusts the regulating valve according to the preset temperature value and the actually detected temperature data; If the heat generated by the compressed gas in a certain heat exchanger is relatively large, resulting in too rapid an increase in the temperature of the heat-conducting oil, the control system will control the regulating valve 306 to increase the opening degree, so that more heat-conducting oil flows into this heat exchanger to enhance the heat recovery effect; If the heat of a certain heat exchanger is relatively small, the regulating valve will reduce the opening degree to reduce the flow rate of the heat-conducting oil; Meanwhile, the heat-conducting oil pump 304 automatically adjusts the output power and flow rate according to the opening degree of the regulating valve 306 and the change of system pressure, ensuring the stable flow of the heat-conducting oil in the entire circulation system and realizing the optimized control of heat recovery for different heat exchangers.

[0073] Preferably, a plurality of branch pipes are led out from the heat storage tank as the heat distribution pipes 307. The heat distribution pipes 307 can be transferred to the gas compression structure through the heat exchanger to realize intake air preheating and improve the compression efficiency; the heat distribution pipes 307 can also be used for the heating requirements in the plant area, such as winter heating, domestic hot water supply, etc. By installing a flow regulating valve and a temperature sensor on the heat distribution pipes 307, the heat distribution can be accurately controlled according to different usage requirements.

[0074] The pressure energy recovery and utilization mechanism includes a pressure energy conversion device and an electric energy storage device.

[0075] The pressure energy conversion device includes an expander 401, a generator 402 and a Roots type low-pressure gas compressor 403.

[0076] The expander 401 preferably adopts a turbine expander. The turbine expander is connected to the gas storage tank through a pipeline. The high-pressure compressed air in the gas storage tank pushes the impeller of the expander 401 to rotate, converting the pressure energy into mechanical energy. In this process, the gas expands and does work externally, its temperature decreases, and its pressure decreases, without the need for an additional heating structure to provide a heat source. A valve is also provided on the connecting pipeline to control the flow rate and flow direction of the high-pressure gas.

[0077] The expander 401 and the generator 402 are connected by a coupling. The rotation of the expander 401 drives the generator 402 to generate electricity. The generator 402 is selected as a high-efficiency permanent magnet generator to realize the efficient conversion of the mechanical energy output by the expander into electrical energy.

[0078] The Roots type low-pressure gas compressor 403 is installed at the exhaust port of the expander 401 and is used to perform a boosting and recycling process on the gas after work, realizing the recycling of the gas.

[0079] The electric energy storage device includes a battery energy storage unit and an electric energy distribution and control unit.

[0080] The battery energy storage unit uses a lithium-ion battery pack as the electric energy storage device. The battery pack is equipped with a battery management system (BMS) to monitor the voltage, current, temperature and other parameters of the battery in real time, ensuring the safe and efficient operation of the battery pack.

[0081] The power distribution and control unit distributes the power generated by the generator to different power-consuming equipment through the power distribution cabinet. For the power-consuming equipment of the gas compression mechanism itself, such as motors and control systems, the recycled power is used first, and the remaining power can be incorporated into the factory power grid or stored in the battery energy storage unit for use during peak power consumption of the system or external power grid failure. Smart meters, circuit breakers, contactors and other equipment are installed in the power distribution cabinet to achieve accurate measurement, control and protection of power.

[0082] This embodiment does not improve the structure and principle of the existing and commonly used electric energy storage device, so this embodiment will not further describe the electric energy storage device.

[0083] In order to achieve effective monitoring and control of the equipment in the above-mentioned devices, as a preferred embodiment, the compressed air energy storage compression system recorded in this embodiment is also provided with an intelligent control network working system for technicians to select when implementing the technical solution of the present invention. Of course, technicians may not use the intelligent control network working system, and the core technical solution recorded in the present invention is the processing process of air compression.

[0084] The intelligent control network working system includes data acquisition device, network transmission device, central control device, and remote monitoring and management device.

[0085] The data acquisition device includes a sensor mechanism and a data acquisition terminal.

[0086] The sensor mechanism includes at least a vibration sensor, a gas composition sensor, and a flow sensor. The vibration sensors are respectively arranged at the rotor of the screw air compressor, the vane of the vane compressor, and the impeller of the centrifugal compressor, and are used to monitor the vibration of the corresponding compression equipment in real time and predict equipment failure.

[0087] The gas composition sensor is installed inside the gas storage tank to monitor the changes in the composition of the compressed air in real time and ensure the quality of the energy storage gas.

[0088] Flow sensors are distributed inside various pipelines of the compressed gas energy storage compression system to monitor the flow of gas at different locations in real time and accurately, providing data support for system operation optimization.

[0089] Since the above-mentioned sensors are monitoring devices commonly used in this technical field, and as mature monitoring technologies, they have a variety of sizes, models, functions, etc. for operators to choose and use. Therefore, this embodiment does not limit the specific models of the above-mentioned sensors and the installation positions in the corresponding equipment. Operators should choose the installation position according to the type and structure of the equipment, and transmit the collected detection data to the outside through the data transmission line.

[0090] The data acquisition terminal preferably adopts a distributed data acquisition terminal to summarize the monitoring data of each sensor in the sensor mechanism. Each data acquisition terminal is equipped with a high-performance analog-to-digital conversion module to convert the analog signals transmitted by the sensors into digital signals, ensuring the accuracy and transmission efficiency of the data. The acquisition terminal communicates with the upper-layer devices through the field bus to achieve fast and stable data transmission.

[0091] The network transmission device includes an industrial Ethernet mechanism, which constructs an industrial Ethernet as the main data transmission network to connect each data acquisition terminal, the central control device, and other related devices. A redundant network topology structure is formed by optical fibers and switches to ensure that data transmission can still proceed normally when some network nodes fail.

[0092] To achieve remote monitoring and management, the network transmission device also includes a wireless communication mechanism, such as a 4G / 5G communication module. The wireless communication module is connected to the industrial Ethernet. While uploading the system data to the cloud server or the remote monitoring center, it can also receive control instructions from remote locations to achieve remote operation.

[0093] The central control device selects an Advantech high-performance industrial control computer, equipped with an Intel Core i7 processor, 32GB of memory, and a 512GB NVMe SSD. A multi-interface PCI-e expansion card is installed to connect various devices. The Linux real-time operating system is adopted to collect sensor data in parallel with multiple threads, filter and denoise it. The GUI is developed using the Qt framework to intuitively display the operating parameters. Combining rules and machine learning algorithms, it issues early warnings and solutions in case of anomalies. With the energy efficiency as the goal, the model predictive control algorithm is used to adjust the parameters, and the hardware devices are correctly connected and grounded.

[0094] The remote monitoring and management device includes a cloud server, remote monitoring software, mobile terminal applications, and permission management.

[0095] The cloud server preferably adopts servers of cloud service providers such as Alibaba Cloud and Tencent Cloud to store the system operation data, configure data storage, analysis, and backup functions to ensure the security and reliability of the data. The security protocol (such as SSL / TLS) is adopted to ensure the security of data transmission; Develop web-based remote monitoring software that supports multi-platform access (Windows, macOS, iOS, Android). Using front-end technologies such as HTML5, CSS3, and JavaScript to achieve an intuitive operation interface, display the system status, and receive warning messages. The back-end adopts the Flask or Django framework of Python to communicate with the central control layer and process data interaction and user operation requests; Develop a mobile application compatible with iOS and Android, using Swift or Kotlin languages, communicate with the cloud server using RESTful APIs, facilitating operators to view system information and receive warnings through mobile devices, and enabling remote control operations; Implement user permission grading, where users at different levels have different operation permissions, ensure system operation security through role assignment, and adopt authentication mechanisms such as OAuth or JWT to guarantee the security of user login and operations.

[0096] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A high-efficiency compressed gas energy storage system based on screw-vane-centrifugal three-stage compression, characterized in that: It includes a gas pre-treatment device, a gas compression device, and an energy collection device; The gas pre-treatment device is used to treat the gas, and the treated gas is input into the gas compression device; The process of treating the gas includes at least one of filtering, mixing, rectifying, dehumidifying, and preheating; The gas compression device is used to compress the treated gas step by step, including a screw compressor, a vane compressor, and a centrifugal compressor connected in sequence through pipelines, which are used to perform first-stage compression, second-stage compression, and third-stage compression on the gas respectively; The energy collection device comprises a pressure energy conversion device and an electric energy storage device. The pressure energy conversion device is used to convert the pressure energy of compressed gas into electric energy, and the electric energy storage device is used to store electric energy.

2. The high-efficiency compressed gas energy storage system based on screw-vane-centrifugal three-stage compression according to claim 1 is characterized in that: The gas pretreatment device comprises a gas mixing chamber and a stirring mechanism arranged inside the gas mixing chamber, which is used for mixing the gas; The gas mixing chamber is provided with an air inlet pipe and an air outlet pipe, which are used for gas input and gas discharge respectively; The stirring mechanism comprises a motor, a circular base fixedly mounted on an output shaft of the motor, and blades mounted on the circular base at equal circumferential intervals. The motor drives the blades to rotate to generate vortices in the gas mixing chamber.

3. The high-efficiency compressed gas energy storage system based on screw-vane-centrifugal three-stage compression according to claim 2 is characterized in that: The gas pretreatment device also includes a guide plate and a spoiler column arranged inside the gas mixing chamber; One end of the guide plate is fixedly arranged on the inner wall of the gas mixing chamber, and the other end points to the axis of the gas mixing chamber, and is arranged in a spiral line along the axial direction of the gas mixing chamber; The spoiler columns are arranged on the bottom surface and the top surface of the inner wall of the gas mixing chamber and are perpendicular to the inner wall of the gas mixing chamber.

4. The high-efficiency compressed gas energy storage system based on screw-vane-centrifugal three-stage compression according to claim 1 is characterized in that: The gas pretreatment device comprises a rectifier tube, inside which a guide vane is arranged for rectifying the gas; the guide vane has a smooth surface and is parallel to the axial direction of the rectifier tube, and its length is set to 0.5-1.0 times the diameter of the rectifier tube.

5. The high-efficiency compressed gas energy storage system based on screw-vane-centrifugal three-stage compression according to claim 1 is characterized in that: The gas pretreatment device includes an adsorption dryer, which is used to dehumidify the gas and control the moisture content of the gas within the range of 0.01%-0.1%.

6. The high-efficiency compressed gas energy storage system based on screw-vane-centrifugal three-stage compression according to claim 1 is characterized in that: The gas pretreatment device comprises a first plate heat exchanger arranged between the gas rectification operation and the gas dehumidification operation, and is used for preheating the gas.

7. The high-efficiency compressed gas energy storage system based on screw-vane-centrifugal three-stage compression according to claim 1 is characterized in that: The gas compression device also includes an air intake processing mechanism for filtering and reducing noise of the gas input into the screw compressor, including a fiber filter, a resistive silencer, and a resistive silencer connected in sequence through a pipeline.

8. The high-efficiency compressed gas energy storage system based on screw-vane-centrifugal three-stage compression according to claim 1 is characterized in that: The gas compression device also includes a shell and tube cooler and a gas-liquid separator, which are respectively arranged between the screw compressor and the vane compressor, and between the vane compressor and the centrifugal compressor, and are used to cool the compressed gas to a designed temperature and dry it.

9. The high-efficiency compressed gas energy storage system based on screw-vane-centrifugal three-stage compression according to claim 1 is characterized in that: The gas compression device also includes an exhaust buffer tank and an air storage tank; the exhaust buffer tank is connected to the centrifugal compressor through a pipeline to evenly distribute the compressed gas inside it and reduce pressure pulsation; the air storage tank is connected to the exhaust buffer tank through a pipeline to store the compressed gas.

10. The high-efficiency compressed gas energy storage system based on screw-vane-centrifugal three-stage compression according to claim 9 is characterized in that: The pressure energy conversion device includes a turbine expander and a generator; The turbo expander is connected to the gas storage tank through a pipeline, and the compressed gas in the gas storage tank drives the turbo expander to operate, converting pressure energy into mechanical energy; The turbine expander is connected to the generator through a coupling, and the turbine expander drives the generator to convert mechanical energy into electrical energy.

11. The high-efficiency compressed gas energy storage system based on screw-vane-centrifugal three-stage compression according to claim 1 is characterized in that: The energy collection device further includes a heat transfer oil circulation system, which includes a second plate heat exchanger, a shell and tube heat exchanger, a heat transfer oil pipeline, a heat transfer oil pump, a PLC, and a heat storage tank; The second plate heat exchanger is arranged at the screw compressor, and the shell and tube heat exchanger is arranged at the vane compressor and the centrifugal compressor; The heat storage tank is connected to the second plate heat exchanger and the shell and tube heat exchanger through a heat transfer oil pipeline to form a heat transfer oil circulation loop; The heat transfer oil pump is installed on the heat transfer oil pipeline and connected to the PLC control host, and the operation of the heat transfer oil pump is controlled by the PLC.

12. The high-efficiency compressed gas energy storage system based on screw-vane-centrifugal three-stage compression according to claim 11 is characterized in that: The heat transfer oil circulation system also includes a temperature sensor and a regulating valve installed on the heat transfer oil pipeline; the PLC uses a Siemens S7--300 PLC, which is connected to the temperature sensor and the regulating valve to receive data transmitted by the temperature sensor and control the operation of the heat transfer oil pump and the regulating valve according to the temperature data transmitted by the temperature sensor.

13. The high-efficiency compressed gas energy storage system based on screw-vane-centrifugal three-stage compression according to any one of claims 1 to 12, characterized in that: The gas is a mixed gas of fresh air and low-pressure air.

14. The high-efficiency compressed gas energy storage system based on screw-vane-centrifugal three-stage compression according to claim 1 is characterized in that: The compressed gas energy storage system also includes an intelligent control network working system, which includes a data acquisition device, a network transmission device, a central control device, and a remote monitoring and management device; The data acquisition device includes a sensor mechanism and a data acquisition terminal; the sensor mechanism includes at least one of a vibration sensor, a gas composition sensor, and a flow sensor; the vibration sensor is respectively arranged at the rotor of the screw air compressor, the vane of the vane compressor, and the impeller of the centrifugal compressor, and is used to monitor the vibration state of the equipment in real time; the gas composition sensor is arranged inside the gas storage device of the compressed gas energy storage system, and is used to monitor the composition change of the gas in real time; the flow sensor is distributed inside each pipeline of the compressed gas energy storage system, and is used to monitor the flow of the gas at different pipeline positions; the data acquisition terminal is used to summarize the monitoring data collected by the sensor mechanism and convert it into a digital signal; The network transmission device includes an industrial Ethernet mechanism, and the central control device includes an industrial control computer; the industrial Ethernet mechanism is connected to the data acquisition terminal and the industrial control computer, and a redundant network topology is formed through optical fibers and switches, which is used to monitor and control the gas pretreatment device, gas compression device, and energy collection device of the compressed gas energy storage system.

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