Near isothermal compressed air energy storage device and methodTechnical Field
The invention relates to the field of gas compression and expansion, in particular to a near isothermal compressed air energy storage device and method.
Background
The compressed air energy storage technology has wide application prospects in the aspects of wind-solar power grid connection, power peak shaving, carbon emission reduction and the like, and the principle is that air is compressed by using low-valley power, wind power, photoelectricity and the like when energy is stored, electric energy is converted into air pressure energy to be stored, and the stored compressed air drives a turbine to do work to generate power when energy is released. The isothermal compressed air energy storage system adopts a series of technical means to enable the compression and expansion processes of air to be approximately isothermal, reduces the compression heating and expansion cooling amplitude of the system, greatly improves the energy utilization efficiency, and has excellent energy storage performance and wide development prospect.
The existing isothermal compressed air energy storage technology utilizes the multi-hydraulic cylinder circulation, liquid piston, spraying and other technologies to promote the realization of isothermal compression and expansion, but in the final stage of compression and the initial stage of expansion, the pressure ratio change rate is high, the brought temperature change is also large, but at the moment, the spray coverage area is small, the gas-liquid contact heat transfer area is constant, the constant temperature effect in the actual compression and expansion process is poor, in addition, the high-low pressure ratio is high to hundreds due to the fact that the pressure change in the compression and expansion process is large, the working pressure of a water pump and a water turbine deviates from the design working condition far, and the actual energy storage/release circulation efficiency is far lower than the ideal isothermal circulation. The factors restrict the development and popularization of the isothermal compressed air energy storage technology, and how to further promote the constant-temperature compression/expansion and improve the system circulation efficiency is the key of the further popularization and application of the technology.
Disclosure of Invention
The invention aims to solve the technical problems of the prior art, and provides a near isothermal compressed air energy storage device and a method, which utilize liquid with large specific heat capacity to reduce the change amplitude of gas temperature through gas-liquid heat exchange.
In order to solve the technical problems, the invention adopts the following technical scheme:
A near isothermal compressed air energy storage device comprises a first hydraulic cylinder, a second hydraulic cylinder, a first ventilation valve, a first drain valve, a first pump set water inlet valve, a first pump set drain valve, a second water inlet valve, a pump set, a high-pressure air tank, a first pipeline, a second high-pressure exhaust pipe and a second high-pressure exhaust valve, wherein the first hydraulic cylinder is communicated with the second hydraulic cylinder through the first pipeline, one end of the first pipeline is communicated with the bottom of the first hydraulic cylinder, the other end of the first pipeline is communicated with the second hydraulic cylinder, the volume of the first hydraulic cylinder is the same as the volume of the second hydraulic cylinder, the first ventilation valve is arranged at the top of the first hydraulic cylinder, the first drain valve, the first pump set water inlet valve, the pump set, the first pump set drain valve and the second water inlet valve are sequentially connected to the first pipeline, the pump set comprises a plurality of water pumps connected in series, the second high-pressure exhaust pipe is arranged at the top of the second hydraulic cylinder, the second hydraulic cylinder is connected with the high-pressure air tank through the second high-pressure exhaust pipe, and the second high-pressure exhaust valve is arranged on the second high-pressure exhaust pipe.
The invention further preferably comprises a second pipeline, a second ventilation valve, a first water inlet valve, a second drain valve, a second pump set water inlet valve, a second pump set drain valve, a first high-pressure exhaust pipe and a first high-pressure exhaust valve, wherein the first hydraulic cylinder is communicated with the second hydraulic cylinder through the second pipeline, one end of the second pipeline is communicated with the bottom of the second hydraulic cylinder, the other end of the second pipeline is communicated with the first hydraulic cylinder, the second ventilation valve is arranged at the top of the second hydraulic cylinder, the first water inlet valve, the second pump set drain valve, the pump set, the second pump set water inlet valve and the second drain valve are sequentially connected to the second pipeline, the first high-pressure exhaust pipe is arranged at the top of the first hydraulic cylinder, the first hydraulic cylinder is connected with the high-pressure air tank through the first high-pressure exhaust pipe, and the first high-pressure exhaust valve is arranged on the first high-pressure exhaust pipe.
The invention further preferably comprises a first porous plate and a second porous plate, wherein the first porous plate is arranged on the inner wall of the first hydraulic cylinder, the vertical height of one end of the second pipeline extending into the first hydraulic cylinder is larger than that of the first porous plate, the second porous plate is arranged on the inner wall of the second hydraulic cylinder, and the vertical height of one end of the first pipeline extending into the second hydraulic cylinder is larger than that of the second porous plate.
As a further preferable aspect of the present invention, the cross sections of the first hydraulic cylinder and the second hydraulic cylinder are each of a variable cross-section structure, and as the heights of the first hydraulic cylinder and the second hydraulic cylinder increase, the cross-sectional areas of the first hydraulic cylinder and the second hydraulic cylinder become larger.
As a further preferable mode of the invention, the water pump further comprises a pump set water changing water inlet pipe, a pump set water changing water outlet pipe, a pump set water changing water inlet valve and a pump set water changing water outlet valve, wherein the pump set water changing water inlet pipe is connected with the water inlet end of the pump set, the pump set water changing water outlet pipe is connected with the water outlet end of the pump set, the pump set water changing water inlet valve is arranged on the pump set water changing water inlet pipe, and the pump set water changing water outlet valve is arranged on the pump set water changing water outlet pipe.
The invention further preferably further comprises a gas expansion power generation device, wherein the gas expansion power generation device comprises a third hydraulic cylinder, a first high-pressure air inlet pipe, a first high-pressure air inlet valve, a first wheel set water outlet valve, a fourth air inlet valve, a third pipeline, a wheel set and a fourth hydraulic cylinder, the first high-pressure air inlet pipe is arranged at the top of the third hydraulic cylinder, the third hydraulic cylinder is connected with the high-pressure air tank through the first high-pressure air inlet pipe, the first high-pressure air inlet valve is arranged on the first high-pressure air inlet pipe, the fourth air inlet valve is arranged at the top of the fourth hydraulic cylinder, the third hydraulic cylinder is communicated with the fourth hydraulic cylinder through the third pipeline, the first wheel set water outlet valve, the wheel set water inlet valve and the first wheel set water inlet valve are sequentially connected to the third pipeline, the wheel set comprises a plurality of water turbines connected in series, and the volume of the third hydraulic cylinder is the same as that of the fourth hydraulic cylinder.
As a further preferred aspect of the present invention, the gas expansion device further includes a second high-pressure gas inlet pipe, a third gas inlet valve, a second high-pressure gas inlet valve, a second wheel set water outlet valve, and a fourth pipe, the second high-pressure gas inlet pipe is disposed at the top of the fourth hydraulic cylinder, the fourth hydraulic cylinder is connected to the high-pressure gas tank through the second high-pressure gas inlet pipe, the second high-pressure gas inlet valve is disposed on the second high-pressure gas inlet pipe, the third gas inlet valve is disposed at the top of the third hydraulic cylinder, the third hydraulic cylinder is communicated with the fourth hydraulic cylinder through the fourth pipe, and the second wheel set water inlet valve, the wheel set, and the second wheel set water outlet valve are sequentially connected to the fourth pipe.
The invention further preferably further comprises a first high-pressure mist pump, a second high-pressure mist pump, a first mist pump pipe, a second mist pump pipe, a first mist valve, a second mist valve, a first nozzle and a second nozzle, wherein two ends of the first mist pump pipe are arranged in the third hydraulic cylinder, two ends of the second mist pump pipe are arranged in the fourth hydraulic cylinder, the first high-pressure mist pump and the first mist valve are connected to the first mist pump pipe, a plurality of first nozzles are arranged at the top of the third hydraulic cylinder and connected to one end of the first mist pump pipe, the second high-pressure mist pump and the second mist valve are connected to the second mist pump pipe, and a plurality of second nozzles are arranged at the top of the fourth hydraulic cylinder and connected to one end of the second mist pump pipe.
As a further preferable aspect of the present invention, the third hydraulic cylinder and the fourth hydraulic cylinder are each of a variable cross-section structure, and as the heights of the third hydraulic cylinder and the fourth hydraulic cylinder decrease, the areas of the cross-sections of the third hydraulic cylinder and the fourth hydraulic cylinder become larger.
The method comprises the steps of (1) storing compressed air in a second hydraulic cylinder, wherein the first hydraulic cylinder is filled with liquid, and when air in the second hydraulic cylinder is compressed, a first ventilation valve, a first drain valve, a first pump set water inlet valve, a first pump set drain valve and a second water inlet valve are opened, and other valves are closed; the pump group operates, and as the first hydraulic cylinder is communicated with the atmosphere, different numbers of water pumps which are operated in series are selected according to the real-time pressure requirement in the second hydraulic cylinder, and liquid is pumped into the second hydraulic cylinder from the first hydraulic cylinder; the compressed air and liquid in the second hydraulic cylinder are subjected to gas-liquid heat transfer at an air-liquid interface along with the increase of the liquid level in the second hydraulic cylinder, the compressed air and liquid absorb compression heat to reduce the temperature of the compressed air, water flowing into the second hydraulic cylinder passes through a porous plate in the second hydraulic cylinder, the water flow passing through the porous plate becomes a plurality of trickles and falls into the lower part of the second hydraulic cylinder, the falling process and the compressed air are fully mixed and exchange heat to further reduce the temperature of the compressed air, the compression ratio of the air is larger and larger along with the increase of the liquid level, the air temperature is higher and higher, the cross section area of the second hydraulic cylinder is increased along with the increase of the liquid level, the contact area of the air and the liquid level is increased, the heat exchange capability is further enhanced, the cooling measures are taken to enable the air compression process to be more approximate to an isothermal process, when the compressed air in the second hydraulic cylinder reaches a certain pressure, the high-pressure air is discharged into the high-pressure air cylinder, the pump set continues to run until the liquid level is full of the hydraulic cylinder, the air in the second hydraulic cylinder is fully compressed into the high-pressure air cylinder, the high-pressure air cylinder is closed, the gas compression process in the second hydraulic cylinder is completed;
Step (2), the first hydraulic cylinder compresses gas for energy storage, wherein a first water inlet valve, a second ventilation valve and a second drain valve are opened, a second pump set water inlet valve and a second pump set drain valve are closed; the energy storage principle is the same as that of the step, so that continuous gas compression is realized through the alternate operation of the first hydraulic cylinder and the second hydraulic cylinder; the third hydraulic cylinder is filled with liquid, and is opened, namely a third high-pressure air inlet valve, a first wheel set water inlet valve, a first spray valve, a first wheel set water outlet valve and a fourth air valve are closed; the first high-pressure fog pump is operated, the high-pressure gas expands to enable the liquid in the third hydraulic cylinder to have a higher water head, the high-water head liquid impacts the wheel set to operate to generate power, the first high-pressure fog pump simultaneously operates to spray the liquid in the third hydraulic cylinder in a fog form through a first fog pump pipe and a first nozzle which are arranged at the top of the third hydraulic cylinder, the expansion space in the third hydraulic cylinder is covered on a large scale, the fog drops are contacted with the expansion gas in the falling process of the fog drops, the heat is released to the expansion gas, the temperature reduction amplitude of the expansion gas is further reduced, the fog drops finally fall into the liquid, the high-pressure gas expands to drive the liquid in the third hydraulic cylinder to generate power through the wheel set until the liquid level in the third hydraulic cylinder is reduced to a certain height, the step (4) and the fourth hydraulic cylinder expands to generate power, the liquid is filled in the hydraulic cylinder at the moment, the second high-pressure fog pump, the second high-pressure air valve, the second three-way valve, the second water inlet valve, the second wheel set and the second water discharge valve are opened, and other valves are closed, the same principle as in the step (3), the high-pressure gas drives the liquid in the second hydraulic cylinder to generate electricity through the wheel set until the liquid level in the fourth hydraulic cylinder is reduced to a certain height, and the high-pressure gas expands to drive the liquid in the second hydraulic cylinder to finish generating electricity through the wheel set, so that continuous electricity generation is realized through the alternate expansion of the high-pressure gas in the third hydraulic cylinder and the fourth hydraulic cylinder.
The invention has the following beneficial effects:
1. The variable cross-section hydraulic cylinder strengthens heat exchange on a gas-liquid interface, namely, when in compression, the gas temperature is increased along with the rise of the liquid level in the hydraulic cylinder, the gas-liquid temperature difference is increased, and the gas-liquid contact heat exchange area is increased at the moment, so as to strengthen heat exchange;
2. The outlet of the water inlet pipe of the hydraulic cylinder is arranged at the upper part of the hydraulic cylinder during compression, so that water flow pumped into the hydraulic cylinder passes through a porous plate in the cylinder and becomes a plurality of thin flows to fall into the lower part of the hydraulic cylinder, and the falling process and the compressed gas are fully mixed for heat exchange, so that the temperature of the compressed gas is further reduced;
3. the water inlet pipe of the hydraulic cylinder is arranged in the hydraulic cylinder during compression, so that the high pressure resistance of a pipeline is avoided when the water inlet pipe is arranged outside;
4. The multi-stage pump set and the water turbine set are adopted, wherein different numbers of high-pressure water pumps are connected in series according to the pressure change of compressed gas during compression, the situation that a single-stage water pump cannot reach target pressure is avoided, different numbers of water turbines are connected in series under a variable water head during expansion, and the power generation potential of the water head is fully utilized.
Drawings
FIG. 1 is a schematic view of the overall structure of the present invention;
FIG. 2 is a schematic illustration of the present invention compressing air in a second hydraulic cylinder;
FIG. 3 is a schematic illustration of the present invention compressing air in a first hydraulic cylinder;
FIG. 4 is a schematic illustration of the present invention when the high pressure gas is expanded in a third hydraulic cylinder to generate electricity;
fig. 5 is a schematic view of the present invention when the high-pressure gas is expanded in the fourth hydraulic cylinder to generate electricity.
The method comprises the following steps: a first hydraulic cylinder, 12, a water inlet end of a second pipeline, 13, a first porous plate, 14, a first ventilation valve 15, a first high-pressure exhaust valve, 16, a first drain valve, 17, a first water inlet valve;
2. The second hydraulic cylinder, 22, the water inlet end of the first pipeline, 23, the second porous plate, 24, the second air vent valve, 25, the second high-pressure exhaust valve, 26, the second drain valve, 27, the second water inlet valve;
31. the second pump set water inlet valve, 32, pump set, 33, pump set series valve, 34, pump set drain valve, 35, first pump set drain valve, 36, second pump set drain valve, 37, first pump set water inlet valve, 38 pump set water inlet valve, 39 pump set water inlet valve;
4. A high pressure gas tank;
5. the third hydraulic cylinder, 52, a first fog pump pipe, 53, a third air valve, 54, a first high-pressure fog pump, 55, a first nozzle, 56, a first spray valve, 57 and a first high-pressure air inlet valve;
6. The fourth hydraulic cylinder, 62, a second fog pump pipe, 63, a fourth air valve, 64, a second high-pressure fog pump, 65, a second nozzle, 66, a second spray valve, 67, a second high-pressure air inlet valve;
71. a first wheel set water inlet valve, a 72 wheel set, a 73 wheel set serial connection type water discharging valve, a 74 wheel set water discharging valve, a 75 second wheel set water discharging valve 76, a first wheel set drain valve, 77, a second wheel set water inlet valve and a 78 wheel set water change switching valve;
81. Third pipe, 82, fourth pipe, 83, first high pressure exhaust pipe, 84, second high pressure exhaust pipe, 85, first high pressure intake pipe, 88, second high pressure intake pipe.
Detailed Description
The invention will be described in further detail with reference to the accompanying drawings and specific preferred embodiments.
In the description of the present invention, it should be understood that the terms "left", "right", "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and "first", "second", etc. do not indicate the importance of the components, and thus are not to be construed as limiting the present invention. The specific dimensions adopted in the present embodiment are only for illustrating the technical solution, and do not limit the protection scope of the present invention.
As shown in figures 1-5, the near isothermal compressed air energy storage device comprises a first hydraulic cylinder 1, a second hydraulic cylinder 2, a first ventilation valve 14, a first drain valve 16, a first pump set water inlet valve 37, a first pump set water drain valve 35, a second water inlet valve 27, a pump set 32, a high-pressure air tank 4, a first pipeline 81, a second high-pressure exhaust pipe 86 and a second high-pressure exhaust valve 25, wherein the first hydraulic cylinder 1 is communicated with the second hydraulic cylinder 2 through the first pipeline 81, one end of the first pipeline 81 is communicated with the bottom of the first hydraulic cylinder 1, the other end of the first pipeline 81 is communicated with the second hydraulic cylinder 2, the volume of the first hydraulic cylinder 1 is the same as the volume of the second hydraulic cylinder 2, the first ventilation valve 14 is arranged at the top of the first hydraulic cylinder 1, the first drain valve 16, the first pump set water inlet valve 37, the pump set 32, the first pump set water drain valve 35 and the second water inlet valve 27 are sequentially connected to the first pipeline 81, the pump set 32 comprises a plurality of water pumps connected in series, the second high-pressure exhaust pipe 86 is arranged at the top of the second hydraulic cylinder 2, the second hydraulic cylinder 2 and the high-pressure tank 4 are connected to the second high-pressure exhaust pipe 86 through the second high-pressure pipeline 86, the second high-pressure pump set water pump set 86 is arranged at the top of the second high-pressure exhaust pipe 86, the second hydraulic cylinder 2 is filled with the liquid in the first high-pressure pump 1, and the second high-pressure pump set water pump 1 is filled with the liquid in the second high-pressure pump 1, and is filled in the first high pressure pump 1. Since the first hydraulic cylinder 1 is communicated with the atmosphere, different numbers of water pumps which are operated in series are selected according to the real-time pressure requirement in the second hydraulic cylinder 2, and the water pumps are realized by adjusting the pump set series valve 33 and the pump set drain valve 34. As the liquid level in the second hydraulic cylinder 2 increases, the volume occupied by air in the second hydraulic cylinder 2 decreases and is compressed, gas-liquid heat transfer occurs between the compressed gas and the liquid at the gas-liquid interface, and the liquid absorbs the compression heat to reduce the temperature of the compressed gas.
When the compressed gas in the second hydraulic cylinder 2 reaches a certain pressure, the second high-pressure exhaust valve 25 is opened, the high-pressure gas is discharged into the high-pressure gas tank 4, the pump group 32 continues to operate until the liquid level is full of the second hydraulic cylinder 2, the gas in the second hydraulic cylinder 2 is fully compressed into the high-pressure gas tank 2, the second high-pressure exhaust valve 25 is closed, and the gas compression process in the second hydraulic cylinder 2 is completed.
The hydraulic system further comprises a second pipeline 82, a second ventilation valve 24, a first water inlet valve 17, a second water outlet valve 26, a second pump set water inlet valve 31, a second pump set water outlet valve 36, a first high-pressure exhaust pipe 85 and a first high-pressure exhaust valve 15, wherein the first hydraulic cylinder 1 and the second hydraulic cylinder 2 are communicated through the second pipeline 82, one end of the second pipeline 82 is communicated with the bottom of the second hydraulic cylinder 2, and the other end of the second pipeline 82 is communicated with the first hydraulic cylinder 1. The second ventilation valve 24 is arranged at the top of the second hydraulic cylinder 2, the first water inlet valve 17, the second pump set drain valve 36, the pump set 32, the second pump set water inlet valve 31 and the second drain valve 26 are sequentially connected to the second pipeline 82, the first high-pressure exhaust pipe 85 is arranged at the top of the first hydraulic cylinder 1, the first hydraulic cylinder 1 and the high-pressure gas tank 4 are connected through the first high-pressure exhaust pipe 85, and the first high-pressure exhaust valve 15 is arranged on the first high-pressure exhaust pipe 85. At this time, the second hydraulic cylinder 2 is filled with liquid, the first hydraulic cylinder 1 is filled with air of standard atmospheric pressure, and the gas in the first hydraulic cylinder 1 is compressed by switching the valve. The pump unit 32 pumps the liquid in the second hydraulic cylinder 2 into the first hydraulic cylinder 1 to compress the gas in the first hydraulic cylinder 1, and the gas compression process in the first hydraulic cylinder 1 is made isothermal by gas-liquid contact, gas-liquid mixing and increasing the gas-liquid contact surface, similar to the compression process described above for the gas in the second hydraulic cylinder 2.
When the gas in the first hydraulic cylinder 1 reaches a certain pressure, the first high-pressure exhaust valve 15 is opened, the high-pressure gas is discharged into the high-pressure gas tank 4, the pump set 32 continues to operate until the liquid level fills the first hydraulic cylinder 1, so that the gas in the first hydraulic cylinder 1 is fully compressed into the high-pressure gas tank 4, the first high-pressure exhaust valve 15 is closed, and the gas compression process in the first hydraulic cylinder 1 is completed. The first hydraulic cylinder 1 is filled with liquid, the second hydraulic cylinder 2 is filled with air with standard atmospheric pressure, and the gas in the second hydraulic cylinder 2 is compressed again through a switching valve. In this way, continuous gas compression is achieved by alternating operation of the first hydraulic cylinder 1 and the second hydraulic cylinder 2.
Still include the pump package trade water inlet tube, pump package trade water drain pipe, pump package trade water inlet valve 38 and pump package trade water drain valve 39, the pump package trade water inlet tube is connected with the water inlet end of pump package 32, and the pump package trade water drain pipe is connected with the drainage end of pump package 32, and pump package trade water inlet valve 38 sets up on the pump package trade water inlet tube, and pump package trade water drain valve 39 sets up on the pump package trade water drain pipe. When the temperature of the liquid in the first hydraulic cylinder 1 or the second hydraulic cylinder 2 is higher and the cooling effect is poorer, the liquid in the first hydraulic cylinder 1 or the second hydraulic cylinder 2 can be replaced through the pump group water changing inlet valve 38 and the pump group water changing outlet valve 39.
The hydraulic system further comprises a first porous plate 13 and a second porous plate 23, wherein the first porous plate 13 is arranged on the inner wall of the first hydraulic cylinder 1 in a supporting mode, the vertical height of one end of the second pipeline 82 extending into the first hydraulic cylinder 1 is larger than that of the first porous plate 13, the second porous plate 23 is arranged on the inner wall of the second hydraulic cylinder 2 in a supporting mode, and the vertical height of one end of the first pipeline 81 extending into the second hydraulic cylinder 2 is larger than that of the second porous plate 23. The water outlet end 22 of the first pipeline is arranged at the upper part of the second porous plate 23, so that water flow pumped into the second hydraulic cylinder 2 passes through the second porous plate 23 in the cylinder, the split flow passing through the holes becomes a plurality of thin flows which fall into the lower part of the second hydraulic cylinder 2, and the falling process is fully mixed with compressed gas for heat exchange, so that the temperature of the compressed gas is further reduced. The water inlet end 12 of the second pipeline is arranged on the upper portion of the first porous plate 13, so that water flow pumped into the first hydraulic cylinder 1 passes through the first porous plate 13 in the cylinder, the split flow passing through the holes becomes a plurality of thin flows which fall into the lower portion of the first hydraulic cylinder 1, and the falling process is fully mixed with compressed gas for heat exchange, so that the temperature of the compressed gas is further reduced.
The sections of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 are of variable section structures, and the larger the area of the cross sections of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 is along with the rise of the heights of the first hydraulic cylinder 1 and the second hydraulic cylinder 2. The gas compression ratio is larger and the gas temperature is higher along with the rise of the liquid level, the cross section area of the first hydraulic cylinder 1 and the cross section area of the second hydraulic cylinder 2 are increased along with the rise of the liquid level, the contact area of the gas and the liquid level are increased, the heat exchange capacity is further enhanced, and the three cooling measures enable the gas compression process to be more approximate to an isothermal process.
The air expansion power generation device comprises a third hydraulic cylinder 5, a first high-pressure air inlet pipe 87, a first high-pressure air inlet valve 57, a first wheel set water inlet valve 71, a first wheel set water outlet valve 76, a fourth air outlet valve 63, a third pipeline 83, a wheel set 72 and a fourth hydraulic cylinder 6. The first high-pressure air inlet pipe 87 is arranged at the top of the third hydraulic cylinder 5, the third hydraulic cylinder 5 is connected with the high-pressure air tank 4 through the first high-pressure air inlet pipe 87, the first high-pressure air inlet valve 57 is arranged on the first high-pressure air inlet pipe 87, the fourth air valve 63 is arranged at the top of the fourth hydraulic cylinder 6, the third hydraulic cylinder 5 and the fourth hydraulic cylinder 6 are communicated through a third pipeline 83, the first wheelset drain valve 76, the wheelset 72 and the first wheelset water inlet valve 71 are sequentially connected to the third pipeline 83, the wheelset 72 comprises a plurality of water turbines connected in series, and the volume of the third hydraulic cylinder 5 is the same as that of the fourth hydraulic cylinder 6.
The novel high-pressure spray pump further comprises a first high-pressure spray pump 54, a second high-pressure spray pump 64, a first spray pump pipe 52, a second spray pump pipe 62, a first spray valve 56, a second spray valve 66, a first spray nozzle 55 and a second spray nozzle 65, wherein two ends of the first spray pump pipe 52 are arranged in the third hydraulic cylinder 5, two ends of the second spray pump pipe 62 are arranged in the fourth hydraulic cylinder 6, the first high-pressure spray pump 54 and the first spray valve 56 are connected to the first spray pump pipe 52, a plurality of first spray nozzles 55 are arranged at the top of the third hydraulic cylinder 5 and are connected to one end of the first spray pump pipe 62, the second high-pressure spray pump 64 and the second spray valve 66 are connected to the second spray pump pipe 62, and a plurality of second spray nozzles 65 are arranged at the top of the fourth hydraulic cylinder 6 and are connected to one end of the second spray pump pipe 62.
The gas expansion device further comprises a second high-pressure gas inlet pipe 88, a third gas-passing valve 53, a second high-pressure gas inlet valve 67, a second wheel set water inlet valve 77, a second wheel set water outlet valve 75 and a fourth pipeline 84, wherein the second high-pressure gas inlet pipe 88 is arranged at the top of the fourth hydraulic cylinder 6, the fourth hydraulic cylinder 6 is connected with the high-pressure gas tank 4 through the second high-pressure gas inlet pipe 88, the second high-pressure gas inlet valve 67 is arranged on the second high-pressure gas inlet pipe 88, the third gas-passing valve 53 is arranged at the top of the third hydraulic cylinder 5, the third hydraulic cylinder 5 is communicated with the fourth hydraulic cylinder 6 through the fourth pipeline 84, and the second wheel set water inlet valve 77, the wheel set 72 and the second wheel set water outlet valve 75 are sequentially connected to the fourth pipeline 84.
In the case of gas expansion power generation, two modes of operation need to be discussed. Firstly, the air valve is regulated by acquiring the temperature and the pressure in the high-pressure air tank and the air pressure and the temperature in the hydraulic tank, and correspondingly regulating the opening of the air valve after the air valve is regulated, so that when the pressure in the hydraulic cylinder is kept approximately constant, the water head in the cylinder is approximately constant, the water turbine can generate electricity under the relatively constant water head, but after the liquid in the cylinder is emptied, the residual air pressure in the cylinder tank can be wasted, and secondly, if a certain amount of high-pressure air is introduced through the air valve, the pressure in the tank is changed, namely the water head is changed, and the water turbine set keeps higher electricity generation efficiency by changing the serial number of the water turbines. The third hydraulic cylinder 5 and the fourth hydraulic cylinder 6 are of variable cross-section structures, and the cross-sectional areas of the third hydraulic cylinder 5 and the fourth hydraulic cylinder 6 are larger along with the decrease of the heights of the third hydraulic cylinder 5 and the fourth hydraulic cylinder 6.
When a certain amount of high-pressure gas is introduced, the third hydraulic cylinder 5 is filled with liquid, and when the high-pressure gas in the high-pressure gas tank 4 expands in the third hydraulic cylinder 5 to generate electricity:
The first high-pressure fog pump 54 of the third hydraulic cylinder 5 is operated, the high-pressure gas expands to enable the liquid in the third hydraulic cylinder 5 to have a higher water head, the high-water head liquid impacts the wheel set 72 to operate to generate power, as the fourth hydraulic cylinder 6 is communicated with the atmosphere, different numbers of water turbines which are operated in series are selected according to the real-time pressure in the third hydraulic cylinder 5, the hydraulic turbine is realized by adjusting the wheel set serial valve 73 and the wheel set drain valve 74, and the generated liquid flows into the fourth hydraulic cylinder 6 through a pipeline.
The temperature of the high-pressure gas is inevitably reduced when the high-pressure gas expands in the third hydraulic cylinder 5, the heat transfer from the liquid to the gas occurs at the gas-liquid interface of the expanded gas, the temperature reduction amplitude of the expanded gas is reduced, the first high-pressure fog pump 54 which runs simultaneously sprays the liquid in the third hydraulic cylinder 5 in a fog form through the first fog pump pipe 52 and the first nozzle 55, the fog drops are contacted with the expanded gas in the falling process, the heat is released to the expanded gas, the temperature reduction amplitude of the expanded gas is further reduced, the fog drops finally fall into the liquid, the cross-sectional area of the third hydraulic cylinder 5 is increased along with the reduction of the liquid level as the falling pressure ratio is increased, the heat exchange capacity of the liquid-gas surface is increased, the descending height of the fog from the spraying to the falling into the liquid is increased, the contact time of the fog and the gas is increased, namely the heat exchange capacity between the fog and the gas is correspondingly increased along with the reduction of the liquid level, and the expansion process is more isothermal along with the reduction of the liquid level. Until the liquid level in the third hydraulic cylinder 5 is lowered to a certain height, the expansion of the high-pressure gas drives the liquid in the third hydraulic cylinder 5 to finish generating electricity through the wheel set 72.
At this time, the fourth hydraulic cylinder 6 is filled with liquid, and the high-pressure gas drives the liquid in the fourth hydraulic cylinder 6 to generate electricity through the wheel set 72 by switching the valve. The high-pressure gas expansion ensures that the liquid in the hydraulic cylinder 6 has higher water head, the high-water head liquid impacts the wheel set 72 to operate for generating electricity, and as the third hydraulic cylinder 5 is communicated with the atmosphere, different numbers of water turbines which are operated in series are selected according to the real-time pressure in the fourth hydraulic cylinder 6, and the generated liquid flows into the third hydraulic cylinder 5 through a pipeline by adjusting the wheel set serial valve 73 and the wheel set drain valve 74. Similar to the above-described process of the high-pressure gas driving the liquid in the third hydraulic cylinder 5 through the wheel set 72 to generate electricity, the expansion process of the high-pressure gas in the fourth hydraulic cylinder 6 tends to be isothermal by the gas-liquid contact, the gas-mist mixing, and the increase of the gas-liquid contact surface. Until the liquid level in the fourth hydraulic cylinder 6 is lowered to a certain height, the expansion of the high-pressure gas drives the liquid in the fourth hydraulic cylinder 6 to finish generating electricity through the hydraulic turbine unit 72.
At this time, the third hydraulic cylinder 5 is filled with liquid, and the high-pressure gas drives the liquid in the third hydraulic cylinder 5 to generate electricity through the wheel set 72 by switching the valve. In this way, continuous power generation is achieved by the alternating expansion of the high-pressure gas in the third hydraulic cylinder 5 and the fourth hydraulic cylinder 6. When the temperature of the liquid in the third hydraulic cylinder 5 and the fourth hydraulic cylinder 6 is lower and the heat exchange effect is poor, the liquid in the third hydraulic cylinder 5 or the fourth hydraulic cylinder 6 can be exchanged through the pump set water exchanging and inlet valve 38, the pump set water exchanging and discharging valve 39 and the wheel set water exchanging and switching valve 78.
A near isothermal compressed air energy storage method comprises the following steps:
The first hydraulic cylinder 1 is filled with liquid, and when the air in the second hydraulic cylinder 2 is compressed, the first ventilation valve 14, the first drainage valve 16, the first pump set water inlet valve 37, the first pump set drainage valve 35 and the second water inlet valve 27 are opened, and other valves are closed; the pump group 32 operates, and as the first hydraulic cylinder 1 is communicated with the atmosphere, different numbers of water pumps which are operated in series are selected according to the real-time pressure requirement in the second hydraulic cylinder 2, so that liquid is pumped into the second hydraulic cylinder 2 from the first hydraulic cylinder 1; the volume occupied by the air in the second hydraulic cylinder 2 is reduced and compressed along with the rise of the liquid level in the second hydraulic cylinder 2, the compressed air and the liquid generate gas-liquid heat transfer at the gas-liquid interface, the liquid absorbs compression heat to reduce the temperature of the compressed air, the water flowing into the second hydraulic cylinder 2 passes through the porous plate 23 in the second hydraulic cylinder 2, the split flow passing through the holes becomes a plurality of thin flows and falls into the lower part of the second hydraulic cylinder 2, the falling process and the compressed air are fully mixed and heat exchanged, the temperature of the compressed air is further reduced, the compression ratio of the air is increased along with the rise of the liquid level, the air temperature is increased along with the rise of the liquid level, the cross-sectional area of the second hydraulic cylinder 2 is increased, the air-liquid level contact area is increased, the heat exchanging capacity is further increased, the cooling measure is adopted, the air compression process is more similar to the isothermal process, when the compressed air in the second hydraulic cylinder 2 reaches a certain pressure, the second high-pressure exhaust valve 25 is opened, the high-pressure air is discharged into the high-pressure air tank 4, the pump set is continuously operated until the liquid level is full of the hydraulic cylinder 2, the air in the second hydraulic cylinder 2 is fully compressed, the high-pressure tank 4 is fully compressed, the high-pressure tank 25 is closed, the gas compression process in the second hydraulic cylinder 2 is completed.
And (2) compressing gas for energy storage by the first hydraulic cylinder 1, namely opening the first water inlet valve 17, the second ventilation valve 24 and the second water outlet valve 26, the second pump set water inlet valve 31 and the second pump set water outlet valve 36, and closing other valves, wherein the energy storage principle is the same as that of the step (1), and continuous gas compression is realized by alternately operating the first hydraulic cylinder 1 and the second hydraulic cylinder 2.
And (3) performing gas expansion power generation on the third hydraulic cylinder 5, wherein the third hydraulic cylinder 5 is filled with liquid, the third high-pressure air inlet valve 57, the first wheel set water inlet valve 71, the first spray valve 56, the first wheel set water outlet valve 76 and the fourth air inlet valve 63 are opened, other valves are closed, the first high-pressure fog pump 54 is operated, the high-pressure gas expands to enable the liquid in the third hydraulic cylinder 5 to have a higher water head, the high-water head liquid impacts the wheel set 72 to perform power generation, the first high-pressure fog pump 54 simultaneously operates to spray the liquid in the third hydraulic cylinder 5 through the first fog pump pipes 52 and the first nozzles 55 which are arranged at the top of the third hydraulic cylinder 5, the expansion space in the hydraulic cylinder is covered in a large range, heat is released to the expansion gas in the process of dropping of fog drops, the temperature drop of the expansion gas is further reduced, the fog drops finally fall into the liquid, and the high-pressure gas expands the liquid in the third hydraulic cylinder 5 to a certain height, and the high-pressure gas drives the liquid in the third hydraulic cylinder 5 to pass through the first fog pump pipes 52 to finish power generation.
And (4) and generating electricity by gas expansion of the fourth hydraulic cylinder 6, wherein the hydraulic cylinder 6 is filled with liquid, the second high-pressure fog pump 64, the second spray valve 66, the second high-pressure air valve 67, the third air valve 54, the second wheel set water inlet valve 77 and the second wheel set water outlet valve 75 are opened, other valves are closed, the same as the electricity generation principle of the step (3), the high-pressure gas drives the liquid in the second hydraulic cylinder 6 to generate electricity through the wheel set 72 until the liquid level in the fourth hydraulic cylinder 6 is reduced to a certain height, the high-pressure gas expands to drive the liquid in the second hydraulic cylinder 6 to generate electricity through the wheel set 72, and thus continuous electricity generation is realized by the alternate expansion of the high-pressure gas in the third hydraulic cylinder 5 and the fourth hydraulic cylinder 6.
The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details of the above embodiments, and various equivalent changes can be made to the technical solution of the present invention within the scope of the technical concept of the present invention, and all the equivalent changes belong to the protection scope of the present invention.