An energy storage system

Abstract

The utility model discloses a kind of energy storage systems, it is related to energy storage technical field, comprising: the compression unit, gas storage unit and expansion unit connected in turn, the gas storage unit with the expansion unit between there is parallel intercommunication first pipeline and second pipeline, the first pipeline has regulating valve, the second pipeline has pressure reducing valve, the both ends of the regulating valve and the pressure reducing valve are respectively provided with cut-off valve.The utility model technical scheme, by parallel intercommunication first pipeline and second pipeline, and regulating valve and pressure reducing valve respectively arranged on it, can provide two different flow and pressure regulating mode for system, to verify the influence of pressure change and constant pressure to expansion side respectively.

Description

Technical Field

[0001] This utility model relates to the field of energy storage technology, and specifically to energy storage systems. Background Technology

[0002] Compressed air energy storage (CAES) is a highly promising large-scale, long-duration physical energy storage technology. Its advantages align perfectly with the current demand for "safe, economical, and sustainable" energy storage in grids with a high proportion of renewable energy. Currently, energy storage systems based on this technology have become a hot research topic for various companies.

[0003] However, the investment in an energy storage system often reaches millions or even tens of millions of yuan. If direct investment is made but the technical route cannot be successfully established, meaning the entire process cannot operate normally, it will result in huge cost losses. If an energy storage system can be designed to verify and test the pressure, temperature, and other parameters and operating conditions of the entire process, the cost investment for energy storage manufacturers can be significantly reduced. Utility Model Content

[0004] In view of this, the present invention provides an energy storage system to solve the problems of verification and experimentation of energy storage systems.

[0005] The energy storage system provided by this utility model includes: a compression unit, a gas storage unit, and an expansion unit connected in sequence. The gas storage unit and the expansion unit have a first pipe and a second pipe connected in parallel. The first pipe has a regulating valve, and the second pipe has a pressure reducing valve. The regulating valve and the pressure reducing valve each have a shut-off valve at both ends.

[0006] This utility model provides two different flow and pressure regulation methods for the system through a first and a second pipe connected in parallel, and a regulating valve and a pressure reducing valve respectively installed on them, thereby verifying the effects of pressure change and constant pressure on the expansion side.

[0007] Optionally, the compression unit includes a screw compressor and a reciprocating compressor connected in sequence, with a buffer tank between the screw compressor and the reciprocating compressor.

[0008] Optionally, the screw compressor, buffer tank, reciprocating compressor, gas storage unit, and expansion unit are each provided with a shut-off valve.

[0009] Optionally, the expansion unit includes a screw expander, the inlet of which is equipped with a heating device.

[0010] Optionally, the gas storage unit includes a gas storage tank, the gas storage tank has a pressure sensor, and the inlet of the gas storage tank is provided with a control valve, the control valve being linked and coordinated with the pressure sensor.

[0011] Optionally, it further includes: a first heat exchange unit, the first heat exchange unit having a first heat exchanger and a second heat exchanger, the first heat exchanger being connected to the compression unit, and the second heat exchanger being connected to the expansion unit.

[0012] Optionally, a bypass pipe is connected between the inlet pipe and the outlet pipe of the second heat exchanger, and the bypass pipe has a regulating valve.

[0013] Optionally, the first heat exchange unit further includes a first cold water pool and a hot water pool, wherein the first cold water pool, the first heat exchanger, the second heat exchanger, and the hot water pool are sequentially connected to form a closed loop.

[0014] Optionally, it further includes: a second heat exchange unit having a third heat exchanger connected between the first cold water tank and the hot water tank.

[0015] Optionally, the second heat exchange unit also includes a second cold water pool and a water tower, with the second cold water pool, the third heat exchanger, and the water tower connected in sequence to form a closed loop. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 A front view of an energy storage system provided for an embodiment of this utility model; Figure 2 for Figure 1 The front view of the first and second pipe sections shown; Figure 3 for Figure 1 The front view of the reciprocating compressor section is shown below; Figure 4 for Figure 1 The front view of the expansion unit segment shown; Figure 5 for Figure 1 The front view of the third heat exchanger section is shown.

[0018] Explanation of reference numerals in the attached figures: 1. Compression unit; 101. Screw compressor; 102. Buffer tank; 103. Reciprocating compressor; 2. Gas storage unit; 201. Control valve; 3. Expansion unit; 301. Heating device; 4. First pipeline; 5. Second pipeline; 6. Shut-off valve; 7. First heat exchange unit; 701. First heat exchanger; 702. Second heat exchanger; 703. Bypass pipe; 704. First cold water tank; 705. Hot water tank; 8. Second heat exchange unit; 801. Third heat exchanger; 802. Second cold water pool; 803. Water tower; 804. First inlet; 805. First outlet; 806. Second inlet; 807. Second outlet. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0020] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0022] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0023] like Figure 1, Figure 2 As shown, this is a specific implementation of the energy storage system provided in this embodiment, including: a compression unit 1, a gas storage unit 2, and an expansion unit 3 connected in sequence. The gas storage unit 2 and the expansion unit 3 have a first pipe 4 and a second pipe 5 connected in parallel. The first pipe 4 has a regulating valve, and the second pipe 5 has a pressure reducing valve. The regulating valve and the pressure reducing valve each have a shut-off valve 6 at both ends.

[0024] In this embodiment, the first pipe 4 and the second pipe 5 are connected in parallel, and a regulating valve and a pressure reducing valve are respectively installed on the two pipes. The system can then have two different flow and pressure regulation methods, thereby verifying the effects of pressure changes and constant pressure on the expansion side.

[0025] In detail, to verify the effect of the transformer system on the expansion side, the second pipeline 5 can be disconnected. The regulating valve on the first pipeline 4 can achieve pressure changes within its own regulation range, but cannot output pressure values ​​beyond that range, thereby verifying the effect of pressure changes on the expansion side.

[0026] To verify the effect of the constant pressure system on the expansion side, disconnect the first pipe 4. The pressure reducing valve on the second pipe 5 can control the pressure passing through it, with the maximum pressure being the pressure in the gas storage tank and the minimum pressure dropping to zero. This allows verification of the effect of the constant pressure system on the expansion side.

[0027] It should be noted that if only a regulating valve is used, the following situation may occur when verifying pressure below its minimum regulating range: the regulating valve does not respond after multiple pressure adjustments, and suddenly at a certain point, the pressure will drop to a level close to closing, making it impossible to verify pressure values ​​below its regulating range.

[0028] like Figure 1 As shown, in some embodiments, the compression unit 1 includes a screw compressor 101 and a reciprocating compressor 103 connected in sequence, with a buffer tank 102 between the screw compressor 101 and the reciprocating compressor 103. During operation, air is pre-compressed by the screw compressor 101 and then enters the buffer tank 102 for buffering. The buffered pre-compressed air then enters the reciprocating compressor 103 for pressurization and compression.

[0029] The buffer tank 102 serves both buffering and filtering functions. Because the screw compressor 101 uses twin screws to compress air during operation, and lubricating oil is added to the contact points between the twin screws to reduce friction, the air pre-compressed by the screw compressor 101 contains oil. The buffer tank 102's temperature drop achieves oil-liquid separation, thus cleaning the pre-compressed air and ensuring a stable intake for the reciprocating compressor 103. The buffer tank 102 is equipped with a pressure sensor linked to the screw compressor 101. When the pressure in the buffer tank 102 exceeds a set value, the screw compressor 101 will stop. The buffer tank 102 has shut-off valves 6 at both its inlet and outlet. These shut-off valves 6 are used to close the buffer tank 102 when maintenance is required, isolating it from the system for replacement or repair.

[0030] It should be noted that, in this embodiment, each of the screw compressor 101, buffer tank 102, reciprocating compressor 103, gas storage unit 2, and expansion unit 3 is equipped with a shut-off valve 6. The function of the shut-off valve 6 is to isolate each device from the system for individual verification.

[0031] like Figure 3 As shown, in this embodiment, the boosting compression of the reciprocating compressor 103 specifically includes three-stage compression: the pre-compressed gas enters the reciprocating compressor 103 for first-stage compression, the gas after first-stage compression enters the first-stage cooler for cooling, the gas after first-stage cooling enters the reciprocating compressor 103 for second-stage compression, the gas after second-stage compression enters the second-stage cooler for cooling, the gas after second-stage cooling enters the reciprocating compressor 103 for third-stage compression, the gas after third-stage compression enters the third-stage cooler for cooling, and the boosted compressed air after third-stage cooling enters the gas storage tank for storage. During this compression process, the gas inlet temperature of the first to third-stage coolers is equal, and the gas outlet temperature of the first to third-stage coolers is equal.

[0032] The compressed air from the reciprocating compressor 103 is stored in an air tank. The pressure in the air tank increases as compressed air is input. The pressure at the outlet of the reciprocating compressor 103 is controlled by external pressure and changes with the pressure inside the air tank. Changes in external pressure do not affect the normal operation of the reciprocating compressor 103, ensuring that the output pressure is always stable.

[0033] like Figure 4As shown, in some embodiments, the expansion unit 3 includes a screw expander, and the inlet of the screw expander is equipped with a heating device 301. Stored compressed air, after being preheated by the heating device 301, enters the screw expander for expansion and power generation. Specifically, the screw expander includes a two-stage expansion process: compressed air heated by the heating device 301 enters the expander for primary expansion; the air after primary expansion then enters the second heat exchanger 702 for secondary heating; the heated air then re-enters the expander for secondary expansion, and the resulting air is used for power generation.

[0034] like Figure 1 As shown, in some embodiments, the gas storage unit 2 includes a gas storage tank, the gas storage tank has a pressure sensor, and the inlet of the gas storage tank is provided with a control valve 201, the control valve 201 being linked and coordinated with the pressure sensor.

[0035] like Figure 1 As shown, in some embodiments, a pressure reducing valve is provided on the outlet pipeline of the air storage tank. The function of the pressure reducing valve is to adjust the pressure at the outlet of the air storage tank so that compressed air is stably input into the screw expander.

[0036] like Figure 1 As shown, in some embodiments, it includes: a first heat exchange unit 7, the first heat exchange unit 7 having a first heat exchanger 701 and a second heat exchanger 702, the first heat exchanger 701 being connected to the compression unit 1, and the second heat exchanger 702 being connected to the expansion unit 3.

[0037] Specifically, the first heat exchanger 701 is connected to the reciprocating compressor 103 and serves as a first to third stage cooler for the reciprocating compressor 103. The second heat exchanger 702 is connected to the screw expander and is used to heat the gas in the screw expander.

[0038] like Figure 3 As shown, in some embodiments, the first heat exchanger 701 serves as the primary, secondary, and tertiary coolers of the reciprocating compressor 103. The high-temperature medium outlet pipes of the primary, secondary, and tertiary coolers are equipped with regulating valves, and the low-temperature medium inlet pipes are equipped with shut-off valves 6. When the outlet temperature is lower than the set temperature, the regulating valves on the outlet pipes will decrease their opening; when the outlet temperature is higher than the set temperature, the regulating valves on the outlet pipes will increase their opening. Furthermore, the two media in the primary to tertiary coolers undergo counter-current heat exchange. That is, the high-temperature gas inlet and high-temperature medium outlet of the primary to tertiary coolers are located at the same end, and the low-temperature gas outlet and low-temperature medium inlet are located at the same end, to achieve counter-current heat exchange.

[0039] like Figure 4As shown, the two media in the second heat exchanger 702 undergo countercurrent heat exchange, that is, the low-temperature gas inlet and the low-temperature medium outlet in the second heat exchanger 702 are located at the same end, and the high-temperature gas outlet and the high-temperature medium inlet are located at the same end. It should be noted that in this embodiment, there are two second heat exchangers 702, which are respectively located at the primary expansion inlet and the secondary expansion inlet of the screw expander, thereby being used for primary heating and secondary heating of the media entering the screw expander, respectively.

[0040] like Figure 1 , Figure 4 As shown, in some embodiments, a bypass pipe 703 is connected between the inlet pipe and the outlet pipe of the second heat exchanger 702, and the bypass pipe 703 has a regulating valve. With this structure, the high-temperature water in the inlet pipe can flow to the outlet pipe through the regulating valve on the bypass pipe 703, so that when the expansion unit 3 does not need much heat, the high-temperature water can be prevented from flowing to the expansion unit 3.

[0041] like Figure 1 As shown, in some embodiments, the first heat exchange unit 7 further includes a first cold water pool 704 and a hot water pool 705, wherein the first cold water pool 704, the first heat exchanger 701, the second heat exchanger 702 and the hot water pool 705 are sequentially connected to form a closed loop.

[0042] In use, the water in the first cold water tank 704 is pumped into the first-stage cooler, second-stage cooler and third-stage cooler of the reciprocating compressor 103. The high-temperature water generated after heat exchange with the compressed air enters the hot water tank 705. The water in the hot water tank 705 is pumped into the second heat exchanger 702 to heat the compressed air for use by the screw expander.

[0043] In the entire system, due to the large amount of energy generated by compressed air, a lot of heat is obtained after heat exchange, resulting in a large amount of hot water in the hot water tank 705. However, the energy generated by the expansion of the expander is small, and less hot water is needed. Therefore, there is a situation of more hot water and less cold water in the entire system. In order to achieve a balance between hot and cold water, a bypass pipe 703 is set between the inlet pipe and the outlet pipe. Through the regulating valve on the bypass pipe 703, a part of the water in the hot water tank 705 is heated by the second heat exchanger 702, and the other part of the water returns to the first cold water tank 704 with the low temperature medium water.

[0044] like Figure 1 , Figure 5As shown, in some embodiments, it further includes: a second heat exchange unit 8, the second heat exchange unit 8 having a third heat exchanger 801, the third heat exchanger 801 being connected between the first cold water pool 704 and the hot water pool 705. Specifically, the third heat exchanger 801 can be a plate heat exchanger.

[0045] The above configuration ensures that the water temperature returning to the first cold water pool 704 meets the temperature requirements of the first cold water pool 704. Before returning to the first cold water pool 704, the hot water enters from the first inlet 804 of the third heat exchanger 801, then flows out from the first outlet 805 before returning to the first cold water pool 704. Thus, the third heat exchanger 801 cools the hot water returning to the first cold water pool 704.

[0046] like Figure 1 As shown, in some embodiments, the second heat exchange unit 8 further includes a second cold water pool 802 and a water tower 803. The second cold water pool 802, the third heat exchanger 801, and the water tower 803 are sequentially connected to form a closed loop. The cooling water used to cool the hot water in the third heat exchanger 801 originates from the second cold water pool 802. The cold water from the second cold water pool 802 enters the third heat exchanger 801 through the second inlet 806, and after heat exchange, flows out of the third heat exchanger 801 through the second outlet 807, then enters the water tower 803, which then supplies water to the second cold water pool 802. In this system, water is recycled, and the water loss is only the portion lost through water vapor evaporation, thus achieving energy saving for the entire system.

[0047] The technical solution provided in this embodiment employs a combination of a screw compressor 101 and a reciprocating compressor 103. Unlike centrifugal compressors where pressure is not adjustable, this combination significantly reduces investment costs. Through the coordinated control of multiple valves, segmented verification of the compression and expansion sides can be achieved. Based on the pressure conditions of different operating conditions, a suitable temperature can be selected, thereby verifying that the solution can meet the temperature and pressure requirements of the entire system.

[0048] The technical solution of this embodiment constructs an energy-saving system. In this system, a heat exchange medium is used to transfer the heat generated by compressed air to expanded air for use. After the heat exchange, the medium returns to the compressed air end to continue absorbing heat, and so on in a continuous cycle. Throughout the entire system, the heat exchange medium is continuously recycled, which is both energy-saving and environmentally friendly.

[0049] Furthermore, in the system of this embodiment, the cooler and heater can exchange heat throughout the entire process. Specifically, the high-temperature medium end and the low-temperature medium end of the cooler and heater are respectively located at the high-temperature gas end and the low-temperature gas end of the cooler and heater. This ensures that the cooler and heater can exchange heat normally throughout the entire process, avoiding reverse heat exchange and further improving energy-saving performance.

[0050] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the present invention.

Claims

1. An energy storage system, characterized in that, include: A compression unit (1), a gas storage unit (2), and an expansion unit (3) are connected in sequence. The gas storage unit (2) and the expansion unit (3) have a first pipe (4) and a second pipe (5) connected in parallel. The first pipe (4) has a regulating valve, and the second pipe (5) has a pressure reducing valve. The regulating valve and the pressure reducing valve have shut-off valves (6) at both ends.

2. The energy storage system according to claim 1, characterized in that, The compression unit (1) includes a screw compressor (101) and a reciprocating compressor (103) connected in sequence, with a buffer tank (102) between the screw compressor (101) and the reciprocating compressor (103).

3. The energy storage system according to claim 2, characterized in that, Each of the screw compressor (101), buffer tank (102), reciprocating compressor (103), gas storage unit (2) and expansion unit (3) has a shut-off valve (6).

4. The energy storage system according to claim 1, characterized in that, The expansion unit (3) includes a screw expander, and the inlet of the screw expander is equipped with a heating device (301).

5. The energy storage system according to claim 1, characterized in that, The gas storage unit (2) includes a gas storage tank, which has a pressure sensor. The inlet of the gas storage tank is equipped with a control valve (201), which works in conjunction with the pressure sensor.

6. The energy storage system according to any one of claims 1-5, characterized in that, Also includes: The first heat exchange unit (7) has a first heat exchanger (701) and a second heat exchanger (702). The first heat exchanger (701) is connected to the compression unit (1), and the second heat exchanger (702) is connected to the expansion unit (3).

7. The energy storage system according to claim 6, characterized in that, A bypass pipe (703) is connected between the inlet pipe and the outlet pipe of the second heat exchanger (702), and the bypass pipe (703) has a regulating valve.

8. The energy storage system according to claim 7, characterized in that, The first heat exchange unit (7) also has a first cold water pool (704) and a hot water pool (705), and the first cold water pool (704), the first heat exchanger (701), the second heat exchanger (702) and the hot water pool (705) are connected in sequence to form a closed loop.

9. The energy storage system according to claim 8, characterized in that, Also includes: The second heat exchange unit (8) has a third heat exchanger (801) connected between the first cold water pool (704) and the hot water pool (705).

10. The energy storage system according to claim 9, characterized in that, The second heat exchange unit (8) also has a second cold water pool (802) and a water tower (803), and the second cold water pool (802), the third heat exchanger (801) and the water tower (803) are connected in sequence to form a closed loop.

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