Compressed air energy storage system

Abstract

The utility model relates to the technical field of compressed air energy storage, in particular to a compressed air energy storage system which comprises an energy storage assembly, an energy release assembly, a plurality of heat exchange medium storage tank sets and a buried type air storage spherical tank, and the energy storage assembly comprises an air compression unit, a multi-stage heat exchanger and a multi-stage cooler. The energy release assembly comprises an air expansion unit and a multi-stage heater; the heat exchange medium storage tank group comprises at least one cold storage tank and at least one heat storage tank; the plurality of heat exchange medium storage tank groups are respectively communicated with the multi-stage heat exchanger and the multi-stage heater; the buried gas storage spherical tank is arranged underground, the input end is connected with the air compression unit, and the output end is connected with the air expansion unit. According to the compressed air energy storage system, multi-stage heat storage and gradient utilization of a heat source can be achieved, and the efficiency of the energy storage system is improved; the buried gas storage spherical tank is deeply buried underground, so that the risk of breakage of the spherical tank body and the production cost are reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to compressed air energy storage technology field, concretely relates to a compressed air energy storage system. BACKGROUND

[0002] The compressed air energy storage power generation technology is a kind of physical energy storage technology with high density, long life, high efficiency and flexible layout, which can enhance the peak shaving capacity of power grid and improve the reliability of power supply of power grid.The compressed air energy storage power generation equipment includes air compression system, heat storage system, gas storage system and expansion power generation system four systems, and the working process is divided into energy storage process and energy release process.

[0003] In the energy storage process, air compression system, heat storage system, gas storage system work, utilize electric energy to compress air to high pressure, and store in gas storage, the residual heat generated in the compression process is used to heat water, and the heated water is stored in high-temperature water tank.In the energy release process, the gas storage system, the heat storage system and the expansion power generation system work, the water in the high-temperature water tank heats the high-pressure air, the heated high-pressure air enters the expansion power generation system, and the heated high-pressure air is used for expansion power generation, and the cooled water is stored in the low-temperature water tank.

[0004] Generally, the higher the gas storage pressure of compressed air energy storage unit is, the higher the unit efficiency will be.But with the continuous rise of gas storage pressure, the pressure resistance requirement of related equipment such as gas storage tank will increase sharply, and high-strength, thicker-wall materials are needed to manufacture gas storage equipment, which not only greatly increases the cost of equipment, but also increases the manufacturing difficulty, and when the pressure is too high, the equipment faces the risk of leakage, rupture and other safety risks increase;In addition, in the energy storage process, the operating condition of the existing last-stage air compressor is not stable, and with the increase of energy storage time, the pressure of gas storage gradually rises, the output power of air compressor also gradually rises, and the exhaust temperature gradually rises with the increase of energy storage time, while the temperature is low at the beginning of operation, and the temperature range is large, which has a certain negative influence on the utilization of waste heat.

[0005] Based on the above, the utility model provides a kind of compressed air energy storage system to solve the problems in prior art. UTILITY MODEL CONTENT

[0006] The utility model aims at providing a kind of compressed air energy storage system, and specific technical solutions are as follows:

[0007] A kind of compressed air energy storage system, comprising:

[0008] Energy storage component, the energy storage component includes air compression unit, multistage heat exchanger and multistage cooler, the air compression unit is connected with multistage heat exchanger and multistage cooler, and the multistage heat exchanger and multistage cooler are connected in series along the flow direction of compressed air;

[0009] The energy releasing assembly comprises an air expansion unit and a multi-stage heater, and the air expansion unit is connected with the multi-stage heater;

[0010] The multiple groups of heat exchange medium storage tank groups comprise at least one cold storage tank and at least one heat storage tank, and the multiple groups of heat exchange medium storage tank groups are respectively connected with the multiple-stage heat exchangers and the multiple-stage heaters;

[0011] The buried gas ball tank is arranged below the ground, the input end of the buried gas ball tank is connected with the air compression unit, and the output end of the buried gas ball tank is connected with the air expansion unit.

[0012] Further, at least one group of heat exchange medium storage tank groups are connected with the heat exchanger at the end of the air compression unit and the heater at the head of the air expansion unit.

[0013] The output end of the cold storage tank is connected with the input end of the heat exchanger, and the input end of the cold storage tank is connected with the output end of the heater.

[0014] The input end of the heat storage tank is connected with the output end of the heat exchanger, and the output end of the heat storage tank is connected with the input end of the heater.

[0015] The cold storage tank and the heat storage tank of each group of heat exchange medium storage tank groups are provided with a pressure balance pipe.

[0016] Further, the air compression unit comprises multiple-stage air compressors arranged in series, wherein the air inlet end of the first-stage air compressor is connected to the atmosphere, the air outlet end of the last-stage air compressor is connected to the input end of the buried gas ball tank, and the air inlet end of the first-stage air compressor is provided with an air filter.

[0017] The air expansion unit comprises multiple-stage air expanders arranged in series, wherein the air inlet end of the first-stage air expander is connected to the output end of the buried gas ball tank, and the air outlet end of the last-stage air expander is connected to the atmosphere.

[0018] The air outlet end of each air compressor is connected with at least one group of heat exchangers and coolers, and the air inlet end of each air expander is connected with at least one group of heaters.

[0019] Further, the buried gas ball tank is arranged at a depth of h below the ground, so that Ph≈(P1+P2) / 2, wherein Ph is the soil pressure outside the buried gas ball tank, Ph=soil density*9.8*h, P1 is the pressure of the compressed air after the output of the buried gas ball tank, and P2 is the pressure of the compressed air after the input of the buried gas ball tank.

[0020] Further, the buried gas storage spherical tank comprises a spherical tank body and a supporting base, the spherical tank body is arranged on the supporting base, the spherical tank body comprises a shell and an inner supporting assembly, and the inner supporting assembly is supported in the shell.

[0021] Further, the inner supporting assembly comprises a central column, a rib plate, a plurality of supporting rods and a plurality of gaskets, the two ends of the central column are connected with the shell through the gaskets, the plurality of supporting rods are connected with the central column through the rib plate, and the plurality of supporting rods are connected with the shell through the gaskets.

[0022] Further, the plurality of supporting rods are symmetrically distributed, and the included angle alpha between two adjacent supporting rods is equal.

[0023] The included angle alpha is any one of 90°, 60°, 45°, 36° and 30°.

[0024] Further, a plurality of reinforcing ribs are arranged on the outside of the shell in a staggered manner, and the spacing of two adjacent reinforcing ribs on the spherical surface is 700mm-1000mm.

[0025] A corrosion-resistant layer is further arranged on the outside of the shell, and the thickness of the corrosion-resistant layer is 6mm-12mm.

[0026] Further, a cooling system is further arranged, the cooling system comprises a cooling tower, and the cooling tower is connected with the multi-stage cooler.

[0027] The technical scheme of the utility model has the following beneficial effects:

[0028] (1) The utility model provides a compressed air energy storage system, including energy storage component, energy release component, multiple sets of heat exchange medium storage tank group and buried gas storage spherical tank, the energy storage component includes air compression unit, multistage heat exchanger and multistage cooler, the air compression unit is connected with multistage heat exchanger and multistage cooler, and multistage heat exchanger and multistage cooler are connected in series along the flow direction of compressed air, the energy release component includes air expansion unit and multistage heater, and the air expansion unit is connected with multistage heater, the heat exchange medium storage tank group includes at least one cold storage tank and at least one heat storage tank, and multiple sets of heat exchange medium storage tank group are connected with multistage heat exchanger and multistage heater respectively, the buried gas storage spherical tank is arranged below the ground, the input end of the buried gas storage spherical tank is connected with the air compression unit, and the output end of the buried gas storage spherical tank is connected with the air expansion unit, in the utility model, through the cooperation of energy storage component, energy release component and multiple sets of heat exchange medium storage tank group, multistage heat storage and cascade utilization of heat source can be realized, and the efficiency of the energy storage system is improved, the buried gas storage spherical tank is used, and is deeply buried underground, the total pressure borne by the spherical tank body can be reduced, the risk of rupture of the spherical tank body is reduced, and the production cost is reduced.

[0029] (2) The buried gas storage spherical tank is deeply buried in the ground, so even if leakage or rupture occurs, the damage to the outside is smaller.

[0030] (3) In the utility model, the buried gas storage spherical tank is deeply buried in the ground to a depth of h, so that Ph≈(P1+P2) / 2, the spherical tank body bears the soil pressure outside and the gas pressure inside, the soil pressure can offset part of the pressure of the gas inside the spherical tank body, correspondingly reduces the total pressure borne by the spherical tank body, and reduces the risk of rupture or leakage of the spherical tank body.

[0031] (4) In the utility model, the shell of the buried gas storage spherical tank is provided with reinforcing ribs outside in an interlaced manner, and is provided with a central column, a rib plate, a supporting rod and a backing plate inside, which assist the shell in bearing the gas pressure, can reduce the wall thickness of the shell to a certain extent, and reduce the manufacturing difficulty and cost of the spherical tank body.

[0032] (5) In the utility model, the buried gas storage spherical tank is deeply buried in the ground, the surrounding soil temperature is constant, the temperature change of the gas inside the spherical tank body is relatively small between day and night and between seasons, which is beneficial to the efficient and stable operation of the compressed air energy storage system.

[0033] (6) In the utility model, the shell splicing steel plates of the shell of the buried gas storage spherical tank are sealed and welded through sealing channel steel, so as to reduce the probability of leakage or rupture of the spherical tank body.

[0034] (7) In the utility model, two groups of heat exchange medium storage tanks are used to carry out double-stage heat storage, at least one group of heat exchange medium storage tanks is connected with the heat exchanger at the end of the air compression unit and the heater at the head of the air expansion unit (to realize the utilization of low-quality heat energy), so as to realize the step utilization of heat sources and improve the efficiency of the energy storage system.

[0035] In addition to the purposes, characteristics and advantages described above, the utility model has other purposes, characteristics and advantages. The utility model will be further described below with reference to the drawings. DRAWINGS

[0036] The drawings constituting a part of the present application are used to provide further understanding of the utility model, and the schematic embodiments of the utility model and the description thereof are used to explain the utility model, and do not constitute improper limitation on the utility model. In the drawings:

[0037] Figure 1 is the overall structure schematic diagram of the compressed air energy storage system in the utility model embodiment;

[0038] Figure 2 is the structure schematic diagram of the buried gas storage spherical tank in the utility model embodiment, wherein, (a) is the front view, (b) is the front sectional view, and (c) is the top sectional view;

[0039] Figure 3 is the external facility schematic diagram of the buried gas ball tank in the embodiment of the utility model;

[0040] Figure 4 is the local structure schematic diagram of the shell;

[0041] Figure 5 is the pressure bearing schematic diagram of the buried gas ball tank in the embodiment of the utility model;

[0042] 1, energy storage assembly, 1.1, primary air compressor, 1.2, secondary air compressor, 1.3, tertiary air compressor, 1.4, four air compressor, 1.5, air filter, 1.6, primary heat exchanger, 1.7, primary cooler, 1.8, secondary heat exchanger, 1.9, secondary cooler, 1.10, tertiary heat exchanger, 1.11, tertiary cooler, 1.12, four heat exchanger, 1.13, four cooler, 2, energy release assembly, 2.1, primary air expander, 2.2, secondary air expander, 2.3, tertiary air expander, 2.4, four air expander, 2.5, primary heater, 2.6, secondary heater, 2.7, tertiary heater, 2.8, four heater, 2.9, generator, 3, heat medium storage tank group, 3.1, # 1 heat storage tank, 3.2, # 2 heat storage tank, 3.3, # 1 cold storage tank, 3.4, # 2 cold storage tank, 4, buried gas ball tank, 4.1, support seat, 4.2, shell, 4.2.1, # 1 shell splicing steel plate, 4.2.2, # 2 shell splicing steel plate, 4.2.3, sealing channel steel, 4.2.4, welding seam between splicing steel plates, 4.2.5, welding seam between sealing channel steel and # 1 shell splicing steel plate, 4.2.6, welding seam between sealing channel steel and # 2 shell splicing steel plate, 4.3, center column, 4.4, rib plate, 4.5, support rod, 4.6, backing plate, 4.7, reinforcing rib, 4.8, anticorrosive layer, 4.9, manhole door, 5, cooling system, 6, sump, 7, drainage pump, 8, stairwell. DETAILED DESCRIPTION

[0043] The embodiments of the utility model are described in detail below in combination with the drawings, but the utility model can be implemented according to the multiple different ways defined and covered.

[0044] In the description of the utility model, it is understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the utility model.

[0045] In addition, the terms "first", "second", and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", and the like can explicitly or implicitly include one or more of the features. In the description of the utility model, unless otherwise stated, the meaning of "multiple" is two or more.

[0046] Embodiment

[0047] Referring to Figure 1 , the utility model provides a compressed air energy storage system, including energy storage subassembly, energy release subassembly, multiple sets of heat exchange medium storage tank group and buried type gas ball tank;

[0048] The energy storage subassembly 1 includes air compression unit, multistage heat exchanger and multistage cooler, the air compression unit is used for compressing air generation high pressure air, the air compression unit is connected with multistage heat exchanger and multistage cooler, the multistage heat exchanger and multistage cooler are connected in series along the flow direction of compressed air, the heat exchanger is used for heat exchange with high pressure air, and the cooler is used to cool the high pressure air after heat exchange.

[0049] In this embodiment, referring to Figure 1 , the air compression unit includes series connection setting primary air compressor 1.1, secondary air compressor 1.2, tertiary air compressor 1.3 and quaternary air compressor 1.4, wherein the air inlet end of primary air compressor 1.1 is connected to atmosphere, and the air outlet end of quaternary air compressor 1.4 is connected to the input end of buried type gas ball tank 4;The air inlet end of primary air compressor 1.1 is provided with air filter 1.5, and the air filter 1.5 filters the air into primary air compressor 1.1.

[0050] In this embodiment, four-stage heat exchanger and four-stage cooler are used, which are primary heat exchanger 1.6, primary cooler 1.7, secondary heat exchanger 1.8, secondary cooler 1.9, tertiary heat exchanger 1.10, tertiary cooler 1.11, quaternary heat exchanger 1.12 and quaternary cooler 1.13, and the air outlet end of each air compressor is connected to a group of heat exchanger and cooler, referring to Figure 1A first-stage air compressor 1.1 is connected in series with a first-stage heat exchanger 1.6 and a first-stage cooler 1.7, a second-stage air compressor 1.2 is connected in series with a second-stage heat exchanger 1.8 and a second-stage cooler 1.9, a third-stage air compressor 1.3 is connected in series with a third-stage heat exchanger 1.10 and a third-stage cooler 1.11, and an outlet end of a fourth-stage air compressor 1.4 is connected in series with a fourth-stage heat exchanger 1.12 and a fourth-stage cooler 1.13.

[0051] The energy releasing assembly 2 comprises an air expansion unit and a multi-stage heater, the air expansion unit is connected with the multi-stage heater, the multi-stage heater is used for heating high-pressure air output by the buried gas storage spherical tank 4; an end of the air expansion unit is connected with the generator 2.9, and the air expansion unit is used for realizing power generation by expansion of the high-pressure air.

[0052] In the embodiment, referring to Figure 1 , the air expansion unit comprises a first-stage air expander 2.1, a second-stage air expander 2.2, a third-stage air expander 2.3 and a fourth-stage air expander 2.4 connected in series, wherein an inlet end of the first-stage air expander 2.1 is connected to an outlet end of the buried gas storage spherical tank 4, and an outlet end of the fourth-stage air expander 2.4 is connected to the atmosphere.

[0053] In the embodiment, four-stage heaters are adopted, namely a first-stage heater 2.5, a second-stage heater 2.6, a third-stage heater 2.7 and a fourth-stage heater 2.8, and an inlet end of each air expander is connected with a group of heaters, referring to Figure 1 The inlet end of the first-stage air expander 2.1 is connected with the first-stage heater 2.5, the second-stage heater 2.6 is connected between the first-stage air expander 2.1 and the second-stage air expander 2.2, the third-stage heater 2.7 is connected between the second-stage air expander 2.2 and the third-stage air expander 2.3, and the fourth-stage heater 2.8 is connected between the third-stage air expander 2.3 and the fourth-stage air expander 2.4.

[0054] The heat exchange medium storage tank group 3 comprises at least one cold storage tank and at least one heat storage tank; a plurality of heat exchange medium storage tank groups 3 are connected with a plurality of heat exchangers and a plurality of heaters respectively; at least one heat exchange medium storage tank group 3 is connected with a heat exchanger at an end of the air compression unit and a heater at a start end of the air expansion unit.

[0055] In the embodiment, the heat exchange medium storage tank group 3 is provided with two groups, each heat exchange medium storage tank group 3 comprises one cold storage tank and one heat storage tank, namely #1 heat storage tank 3.1 and #1 cold storage tank 3.3, and #2 heat storage tank 3.2 and #2 cold storage tank 3.4; a pressure balance pipe is arranged between the #1 heat storage tank 3.1 and the #1 cold storage tank 3.3 and between the #2 heat storage tank 3.2 and the #2 cold storage tank 3.4.

[0056] In this embodiment, the output end of the #1 cold storage tank 3.3 is connected with the input end of the four-stage heat exchanger 1.12, the output end of the four-stage heat exchanger 1.12 is connected with the input end of the #1 heat storage tank 3.1, the output end of the #1 heat storage tank 3.1 is connected with the input end of the first-stage heater 2.5, and the output end of the first-stage heater 2.5 is connected with the input end of the #1 cold storage tank 3.3.

[0057] The output end of the #2 cold storage tank 3.4 is connected with the input end of the first-stage heat exchanger 1.6, the second-stage heat exchanger 1.8 and the third-stage heat exchanger 1.10 respectively, the output end of the first-stage heat exchanger 1.6, the second-stage heat exchanger 1.8 and the third-stage heat exchanger 1.10 is connected with the input end of the #2 heat storage tank 3.2 respectively, the output end of the #2 heat storage tank 3.2 is connected with the input end of the second-stage heater 2.6, the third-stage heater 2.7 and the four-stage heater 2.8 respectively, and the output end of the second-stage heater 2.6, the third-stage heater 2.7 and the four-stage heater 2.8 is connected with the input end of the #2 cold storage tank 3.4 respectively.

[0058] In the energy storage process, the cold water in the #1 cold storage tank 3.3 flows into the four-stage heat exchanger 1.12 to recover the heat in the high-pressure air and then enters the #1 heat storage tank 3.1 for storage, and the cold water in the #2 cold storage tank 3.4 flows into the first-stage heat exchanger 1.6, the second-stage heat exchanger 1.8 and the third-stage heat exchanger 1.10 respectively to recover the heat in the high-pressure air and then enters the #2 heat storage tank 3.2 for storage.

[0059] In the energy release process, the hot water in the #1 heat storage tank 3.1 enters the first-stage heater 2.5 to heat the air, and then enters the #1 cold storage tank 3.3 after heat exchange and cooling, the hot water in the #2 heat storage tank 3.2 enters the second-stage heater 2.6, the third-stage heater 2.7 and the four-stage heater 2.8 respectively to heat the air, and then enters the #2 cold storage tank 3.4 after heat exchange and cooling.

[0060] In the utility model, because the first three air compressors run stably, the exhaust temperature is maintained at a high level, and high-quality heat storage can be realized, the efficiency of the second, third and fourth air expanders is relatively high, and the shaft power is relatively high, and the contribution to power generation is relatively large, so high-quality heat energy is preferentially used, the fourth air compressor is always in a variable operating state, the exhaust temperature changes greatly, and the temperature is relatively low, and it can be used for recovering low-quality heat energy, the first air expander has a large throttling loss, and the inlet pressure changes greatly, so the efficiency and output shaft power are low, therefore, the low-quality heat recovered from the output end of the fourth air compressor is used in the first-stage heater 2.5 to heat the air, and the step utilization of heat storage is realized, and the efficiency of the energy storage system is improved.

[0061] The cooling system 5 includes a cooling tower connected with the multi-stage coolers, and during the energy storage process, the cooling tower recovers the high-temperature cooling water in the first-stage cooler 1.7, the second-stage cooler 1.9, the third-stage cooler 1.11 and the fourth-stage cooler 1.13, and after the cooling water is cooled into low-temperature cooling water in the cooling tower, the low-temperature cooling water is used to cool the air in the first-stage cooler 1.7, the second-stage cooler 1.9, the third-stage cooler 1.11 and the fourth-stage cooler 1.13 again, and the cooling water is recycled.

[0062] The buried gas ball tank 4 is arranged below the ground, an input end of the buried gas ball tank 4 is connected with the fourth-stage air compressor, and an output end of the buried gas ball tank 4 is connected with the first-stage air expander.

[0063] Referring to Figure 5 , the buried gas ball tank 4 is arranged below the ground at a depth of h (h is the distance from the ground to the top end of the buried gas ball tank), so that Ph≈(P1+P2) / 2, wherein Ph is the soil pressure outside the buried gas ball tank 4, Ph=soil density*9.8*h, P1 is the pressure of the compressed air after the buried gas ball tank 4 outputs the compressed air, and P2 is the pressure of the compressed air after the buried gas ball tank 4 inputs the compressed air.

[0064] Referring to Figure 2 (a)-(c), the buried gas ball tank 4 includes a ball tank body and a support base 4.1, the ball tank body is arranged on the support base 4.1, the ball tank body includes a shell 4.2 and an inner support assembly, and the inner support assembly is supported inside the shell 4.2.

[0065] The inner support assembly includes a center column 4.3, a rib plate 4.4, a plurality of support rods 4.5 and a plurality of pad plates 4.6, the center column 4.3 is arranged at the inner center position of the ball tank body, both ends of the center column 4.3 are connected with the shell 4.2 through the pad plates 4.6, a plurality of the support rods 4.5 are connected with the center column 4.3 through the rib plate 4.4, and a plurality of the support rods 4.5 are connected with the shell 4.2 through the pad plates 4.6.

[0066] The plurality of the support rods 4.5 are symmetrically distributed, and the included angle α between two adjacent support rods 4.5 is equal; the included angle α is any one of 90°, 60°, 45°, 36° and 30°.

[0067] In the embodiment, the center column 4.3 can bear the tensile force of (P2-Ph)×π×1 / 4×D 2 , and D is the inner diameter of the shell 4.2.

[0068] The support rod 4.5 can bear the tensile force of (P2-Ph)×2×π×1 / 4×D 2The number of support rods 4.5 is determined as n / 2.

[0069] The shell 4.2 is externally staggered with a plurality of reinforcing ribs 4.7, and the interval of two adjacent reinforcing ribs 4.7 on the spherical surface is 700-1000 mm, so as to increase the strength of the shell 4.2.

[0070] In the embodiment, the shell 4.2 of the buried gas storage spherical tank 4 is externally staggered with reinforcing ribs 4.7, and the shell 4.2 is internally provided with a central column 4.3, a rib plate 4.4, a support rod 4.5 and a pad plate 4.6, which assist the shell 4.2 to bear the gas pressure, can reduce the wall thickness of the shell 4.2 to a certain extent, and reduce the manufacturing difficulty and cost of the spherical tank body.

[0071] The shell 4.2 is externally further provided with a corrosion-resistant layer 4.8, the thickness of the corrosion-resistant layer 4.8 is 6-12 mm, and the shell 4.2 can be covered with glass fiber reinforced plastic, so that the shell 4.2 can be effectively prevented from being corroded by soil.

[0072] Referring to Figure 3 , the buried gas storage spherical tank 4 is provided with a drain pipe at the bottom, is connected to a water collecting pit 6, and is then pumped out by a drain pump 7 and discharged to other places on the ground. The buried gas storage spherical tank 4 is externally provided with a manhole door 4.9 and a stairwell 8, and an operating personnel can go underground from the stairwell 8 and then enter the tank from the manhole door 4.9 to perform maintenance.

[0073] In the embodiment, the shell 4.2 is formed by sealing and welding of shell spliced steel plates, and the structure of the welding position is shown in Figure 4 , the #1 shell spliced steel plate 4.2.1 is welded with the #2 shell spliced steel plate 4.2.2 to form an inter-spliced steel plate welding seam 4.2.4, the sealing channel steel 4.2.3 is covered on the inter-spliced steel plate welding seam 4.2.4 and is welded with the #1 shell spliced steel plate 4.2.1 and the #2 shell spliced steel plate 4.2.2 respectively, and the sealing channel steel and the #1 shell spliced steel plate welding seam 4.2.5 and the sealing channel steel and the #2 shell spliced steel plate welding seam 4.2.6 are formed, so as to seal the inter-spliced steel plate welding seam 4.2.4 and reduce the probability of leakage or rupture of the spherical tank body. The sealing channel steel 4.2.3 can be selected from any one of [6.3, [8, [10, [12.6 and [14a.

[0074] The utility model adopts the buried gas storage spherical tank 4, the spherical tank body is deeply buried below the ground, and part of the pressure of the gas in the spherical tank body is offset by the pressure of the soil. The shell is externally provided with transversely and longitudinally staggered reinforcing ribs, and is internally provided with a central column 4.3 and a support rod 4.5, which assist the shell to bear a certain gas pressure, so as to reduce the wall thickness of the shell and the overall cost of the spherical tank body.

[0075] When the compressed air energy storage system is operated, the following steps are included:

[0076] Energy storage phase: air compression unit compresses air to generate high pressure air, cold water in #1 cold storage tank 3.3 flows into four-stage heat exchanger 1.12 to recover heat in high pressure air to generate hot water stored in #1 heat storage tank 3.1, and the cooled high pressure air is output to the buried gas ball tank 4; the cold water in #2 cold storage tank 3.4 flows into the first-stage heat exchanger 1.6, the second-stage heat exchanger 1.8 and the third-stage heat exchanger 1.10 respectively to recover heat in high pressure air to generate hot water stored in #2 heat storage tank 3.2.

[0077] Energy release phase: hot water in #1 heat storage tank 3.1 flows into the first-stage heater 2.5 to heat air, and the cooled hot water is output to #1 cold storage tank 3.3; hot water in #2 heat storage tank 3.2 flows into the second-stage heater 2.6, the third-stage heater 2.7 and the fourth-stage heater 2.8 respectively to heat air, and the cooled hot water is output to #2 cold storage tank 3.4; the air expansion unit expands the heated high pressure air and generates electricity through the generator 2.9.

[0078] The preferred embodiments of the present application have been described above by way of example only, not for limitation, and various changes and modifications can be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A compressed air energy storage system, characterized in that, include: An energy storage component (1) includes an air compression unit, a multi-stage heat exchanger and a multi-stage cooler. The air compression unit is connected to the multi-stage heat exchanger and the multi-stage cooler. The multi-stage heat exchanger and the multi-stage cooler are connected in series along the direction of compressed air flow. The energy release component (2) includes an air expansion unit and a multi-stage heater, wherein the air expansion unit is connected to the multi-stage heater; Multiple sets of heat exchange medium storage tank groups (3), the heat exchange medium storage tank group (3) includes at least one cold storage tank and at least one heat storage tank; the multiple sets of heat exchange medium storage tank groups (3) are respectively connected to a multi-stage heat exchanger and a multi-stage heater; The buried balloon tank (4) is located below ground level. The input end of the buried balloon tank (4) is connected to an air compression unit, and the output end of the buried balloon tank (4) is connected to an air expansion unit.

2. The compressed air energy storage system according to claim 1, characterized in that, At least one heat exchange medium storage tank group (3) is connected to the heat exchanger at the end of the air compression unit and the heater at the beginning of the air expansion unit; The output end of the cold storage tank is connected to the input end of the heat exchanger, and the input end of the cold storage tank is connected to the output end of the heater. The input end of the heat storage tank is connected to the output end of the heat exchanger, and the output end of the heat storage tank is connected to the input end of the heater. Each heat exchange medium storage tank group (3) has a pressure balancing pipe installed between the cold storage tank and the heat storage tank.

3. The compressed air energy storage system according to claim 1, characterized in that, The air compression unit includes a multi-stage air compressor arranged in series, wherein the air inlet of the first-stage air compressor is connected to the atmosphere, and the air outlet of the last-stage air compressor is connected to the input of the buried air storage tank (4); the air inlet of the first-stage air compressor is provided with an air filter. The air expansion unit includes a series of multi-stage air expanders, wherein the air inlet of the first-stage air expander is connected to the output of the buried air storage tank (4), and the air outlet of the last-stage air expander is connected to the atmosphere. Each stage of the air compressor has at least one set of heat exchangers and coolers connected to its outlet, and each stage of the air expander has at least one set of heaters connected to its inlet.

4. The compressed air energy storage system according to claim 1, characterized in that, The buried air storage tank (4) is set underground at a depth of h, such that Ph≈(P1+P2) / 2, where Ph is the soil pressure outside the buried air storage tank (4), Ph = soil density * 9.8 * h, P1 is the pressure after the buried air storage tank (4) outputs compressed air, and P2 is the pressure after the buried air storage tank (4) inputs compressed air.

5. A compressed air energy storage system according to claim 1, characterized in that, The buried gas storage tank (4) includes a tank body and a support base (4.1), the tank body being disposed on the support base (4.1); the tank body includes a shell (4.2) and an inner support assembly, the inner support assembly being supported inside the shell (4.2).

6. A compressed air energy storage system according to claim 5, characterized in that, The internal support assembly includes a central column (4.3), ribs (4.4), multiple support rods (4.5), and multiple pads (4.6). The two ends of the central column (4.3) are connected to the shell (4.2) through the pads (4.6). The multiple support rods (4.5) are connected to the central column (4.3) through the ribs (4.4), and the multiple support rods (4.5) are connected to the shell (4.2) through the pads (4.6).

7. A compressed air energy storage system according to claim 6, characterized in that, The multiple support rods (4.5) are symmetrically distributed and the included angle α between two adjacent support rods (4.5) is equal; The included angle α can be any one of 90°, 60°, 45°, 36° and 30°.

8. A compressed air energy storage system according to claim 5, characterized in that, The outer surface of the shell (4.2) is provided with multiple reinforcing ribs (4.7) arranged in an alternating manner, and the distance between two adjacent reinforcing ribs (4.7) on the spherical surface is 700mm to 1000mm; The outer surface of the housing (4.2) is also provided with an anti-corrosion layer (4.8), the thickness of which is 6mm to 12mm.

9. A compressed air energy storage system according to any one of claims 1-8, characterized in that, It also includes a cooling system (5), which includes a cooling tower connected to a multi-stage cooler.

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