Liquid-phase cold storage cold utilization device and method for liquid air energy storage

Abstract

The invention relates to the technical field of energy storage, and particularly discloses a liquid-phase cold storage and cold utilization device and method for liquid air energy storage, and the device comprises a cold utilization heat exchanger which is used for carrying out heat exchange on a cold storage medium and normal-temperature air to obtain a hot cold storage medium and liquid air; the cold recoverer is used for exchanging heat between the hot cold storage medium and liquid air to obtain a cold storage medium and normal-temperature air; the cold storage medium storage unit is used for conveying the stored cold storage medium to the cold heat exchanger and receiving the hot cold storage medium returned by the cold heat exchanger; and the cold storage device is used for storing the heat cold storage medium, conveying the stored heat cold storage medium to the cold recoverer and receiving the cold cold storage medium returned by the cold recoverer. The cold storage medium and the heat storage medium are efficiently transferred and utilized among the cold heat exchanger, the cold recoverer and the cold storage medium storage unit, the defects that a storage tank of a traditional cold storage system is large in size and high in investment are overcome, and then the economic benefit of liquid air energy storage is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage, and in particular to a liquid phase cold storage device and method for liquid air energy storage. Background Art

[0002] Liquid air energy storage is a technical means to improve the stability of the power grid. It can make up for the randomness and intermittency of renewable energy generation, stabilize fluctuations, and fill peaks and valleys. In the energy storage process of liquid air energy storage, during the low electricity consumption period, the surplus electricity is used to compress the liquefied air and store the electricity in the form of liquid air; in the energy release process of liquid air energy storage, during the peak electricity consumption period, the liquid air is gasified, expanded to generate electricity, and the energy in the liquid air is released to fill the electricity demand during the peak electricity consumption period, avoiding the problem of unstable renewable energy generation.

[0003] In the process of liquid air energy storage, a large amount of cold energy is required to lower the air temperature to complete liquefaction; in the process of liquid air energy release, cold energy needs to be recovered from the low-temperature liquid air to complete the regeneration of the cold storage medium.

[0004] Since the energy storage and energy release processes of the liquid-air energy storage system do not work at the same time, a cold storage system is required to absorb cold from the liquid air in the energy release process, and then release cold to the air that needs to be liquefied in the energy storage process, so as to improve the energy utilization efficiency of the liquid-air energy storage system and reduce the refrigeration loss. The cold storage system of liquid-air energy storage requires a method to store cold storage medium. The traditional cold storage medium storage system consists of a cold cold storage medium storage tank and a hot cold storage medium storage tank. The cold cold storage medium storage tank is used to store cold cold storage medium for providing cold, and the hot cold storage medium storage tank is used to store hot cold storage medium after heat exchange. The volume of each storage tank needs to be able to fully accommodate all the cold storage medium required to complete the liquefaction of air during the operation cycle of the liquid-air energy storage system. Therefore, the storage tank volume of the traditional cold storage medium storage system is affected by the amount of liquefied air. When a large amount of air needs to be liquefied, it needs to store a large amount of cold storage medium, which leads to an excessively large total volume of the storage tank, which increases investment and limits economic benefits. Therefore, it is urgent to develop a new type of cold storage medium storage system for liquid air energy storage.

[0005] Based on this technical background, the present invention studies a liquid phase cold storage device and method for liquid air energy storage. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention proposes a liquid phase cold storage device and method for liquid air energy storage. The device improves the shortcomings of traditional cold storage systems such as large tank size and high investment by arranging cold storage media and hot cold storage media for efficient transfer and utilization between a cold heat exchanger, a cold recovery device and a cold storage medium storage unit, thereby improving the economic benefits of liquid air energy storage.

[0007] In order to achieve the above-mentioned object, the first aspect of the present invention provides a liquid phase cold storage device for liquid air energy storage, comprising:

[0008] A cold heat exchanger is used to exchange heat between the cold storage medium and the normal temperature air to obtain the hot storage medium and liquid air;

[0009] A cold recovery device, used for exchanging heat between the hot cold storage medium and the liquid air to obtain the cold cold storage medium and the normal temperature air;

[0010] The cold storage medium storage unit is used to deliver the stored cold cold storage medium to the cold heat exchanger and receive the hot cold storage medium returned by the cold heat exchanger; and to deliver the stored hot cold storage medium to the cold recovery device and receive the cold cold storage medium returned by the cold recovery device.

[0011] A second aspect of the present invention provides a method performed in the above-mentioned device, wherein the method comprises the following steps:

[0012] The cold cold storage medium stored in the cold storage medium storage unit is sent to the cold heat exchanger, in which the cold cold storage medium exchanges heat with the air at room temperature to obtain the hot cold storage medium and liquid air, and the obtained hot cold storage medium is returned to the cold storage medium storage unit;

[0013] The hot cold storage medium stored in the cold storage medium storage unit is sent to the cold recovery device, in which the hot cold storage medium exchanges heat with liquid air to obtain cold cold storage medium and room temperature air, and the obtained cold cold storage medium is returned to the cold storage medium storage unit.

[0014] The effects of the present invention are:

[0015] (1) The liquid phase cold storage device for liquid air energy storage proposed in the present invention improves the shortcomings of the traditional cold storage system, such as large storage tank volume and high investment, by arranging the cold storage medium and the hot cold storage medium to be efficiently transferred and utilized between the cold heat exchanger, the cold recovery device and the cold storage medium storage unit, thereby improving the economic benefits of liquid air energy storage.

[0016] (2) The liquid phase cold storage method of liquid air energy storage proposed in the present invention stores cold storage medium and hot storage medium through variable temperature tanks, low temperature tanks, and medium temperature tanks, and flexibly transports the cold storage medium and hot storage medium to cold heat exchangers and cold recovery devices for heat exchange, so that the total volume of the storage tank is greatly reduced compared with the total volume of the storage tank of the traditional cold and hot dual storage tank system, thereby reducing the investment cost.

[0017] (3) The liquid phase cold storage method of liquid air energy storage proposed in the present invention is that when the energy storage process is in progress, in the cold heat exchanger, the cold storage medium in the variable temperature tank and the low temperature tank is used for heat exchange in batches, and the hot cold storage medium after the heat exchange is completed is stored in the variable temperature tank and the medium temperature tank in batches; when the energy release process is in progress, in the cold recovery device, the hot cold storage medium in the variable temperature tank and the medium temperature tank is used for heat exchange in batches, and the cold cold storage medium after the heat exchange is completed is stored in the low temperature tank and the medium temperature tank in batches, which not only improves the utilization rate of the variable temperature tank, the low temperature tank and the medium temperature tank, but also makes the empty energy storage and energy release operations more flexible.

[0018] (4) In the liquid phase cold storage device for liquid air energy storage proposed by the present invention, the variable temperature tank can store both cold storage medium and hot cold storage medium, and the material of the variable temperature tank can withstand the temperature change caused by storing cold storage medium to storing hot cold storage medium, thereby increasing the utilization efficiency of the variable temperature tank and ensuring the safety and reliability of the liquid phase cold storage operation of the liquid air energy storage.

[0019] (5) In the liquid phase cold storage device for liquid air energy storage proposed in the present invention, outlet pipelines of the variable temperature tank, the low temperature tank and the medium temperature tank are provided with respective independent circulation pumps and switch valves, thereby ensuring that the cold cold storage medium and / or the hot cold storage medium circulates on the set circulation path, making the liquid phase cold storage operation of the liquid air energy storage safe and controllable.

[0020] (6) The liquid phase cold storage device for liquid air energy storage proposed in the present invention can be one or at least two connected in series. The at least two devices connected in series can cool the room temperature air to liquid air in stages, and / or heat the liquid air to room temperature air in stages. By adjusting the number of devices in series, different cold storage requirements can be flexibly met.

[0021] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0023] Figure 1 This is a schematic structural diagram of the liquid phase cold storage device for liquid air energy storage proposed in the present invention.

[0024] Description of reference numerals:

[0025] 1-cold heat exchanger, 2-cold recovery device, 3-cold storage medium storage unit;

[0026] 101-variable temperature tank, 102-low temperature tank, 103-medium temperature tank;

[0027] 1001-normal temperature air, 1002-liquid air, 1003-cold cold storage medium, 1004-hot cold storage medium. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0029] In the present disclosure, unless otherwise stated, directional words such as "upper" and "lower" generally refer to the upper and lower parts of a device in normal use. Figure 1 In the drawing direction, "inside" and "outside" refer to the outline of the device. In addition, the terms "first, second, third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first, second, third" may explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0030] The present invention provides a liquid phase cold storage device for liquid air energy storage, such as Figure 1 As shown, including:

[0031] A cold heat exchanger 1 is used to exchange heat between the cold cold storage medium 1003 and the normal temperature air 1001 to obtain the hot cold storage medium 1004 and the liquid air 1002;

[0032] The cold recovery device 2 is used for exchanging heat between the hot cold storage medium 1004 and the liquid air 1002 to obtain the cold cold storage medium 1003 and the normal temperature air 1001;

[0033] The cold storage medium storage unit 3 is used to deliver the stored cold cold storage medium 1003 to the cold heat exchanger 1 and receive the hot cold storage medium 1004 returned by the cold heat exchanger 1; and to deliver the stored hot cold storage medium 1004 to the cold recovery device 2 and receive the cold cold storage medium 1003 returned by the cold recovery device 2.

[0034] In the present invention, by arranging cold storage medium 1003 and hot cold storage medium 1004 for efficient transfer and utilization between cold heat exchanger 1, cold recovery device 2 and cold storage medium storage unit 3, the shortcomings of large storage tank volume and high investment of traditional cold storage system are improved, thereby improving the economic benefits of liquid air 1002 energy storage.

[0035] According to the present invention, the cold heat exchanger 1 is provided with a normal temperature air inlet, a liquid air outlet, a first low temperature medium inlet, a second low temperature medium inlet, a first high temperature medium outlet, and a second high temperature medium outlet;

[0036] The cold recovery device 2 is provided with a normal temperature air outlet, a liquid air inlet, a first high temperature medium inlet, a second high temperature medium inlet, a first low temperature medium outlet, and a second low temperature medium outlet;

[0037] The cold storage medium storage unit 3 includes a variable temperature tank 101, a low temperature tank 102 and a medium temperature tank 103;

[0038] The first low-temperature medium outlet is connected to the first low-temperature medium inlet via the low-temperature tank 102;

[0039] The first high temperature medium outlet is connected to the first high temperature medium inlet via the medium temperature tank 103;

[0040] The second low-temperature medium inlet, the second high-temperature medium outlet, the second high-temperature medium inlet, and the second low-temperature medium outlet are all connected to the temperature-changing tank 101 .

[0041] In the present invention, both cold cold storage medium 1003 and hot cold storage medium 1004 can be stored in the temperature variable tank 101, and the material of the temperature variable tank 101 can withstand the temperature change caused by storing cold cold storage medium 1003 to storing hot cold storage medium 1004, while increasing the utilization efficiency of the temperature variable tank 101 and ensuring the safety and reliability of the cold operation of the liquid phase cold storage of liquid air 1002 energy storage.

[0042] According to the present invention, the cold storage medium 1003 in the cold heat exchanger 1 flows in the opposite direction to the normal temperature air 1001;

[0043] The hot cold storage medium 1004 and the liquid air 1002 in the cold recovery device 2 flow in opposite directions;

[0044] The outlet pipelines of the variable temperature tank 101, the low temperature tank 102 and the medium temperature tank 103 are provided with independent circulation pumps and switch valves;

[0045] The circulation pump and the switch valve are used to control the circulation of the cold storage medium 1003 and / or the hot storage medium 1004 on a set circulation path.

[0046] In the present invention, the outlet pipelines of the variable temperature tank 101, the low temperature tank 102 and the medium temperature tank 103 are provided with independent circulation pumps and switch valves, which ensure that the cold storage medium 1003 and / or the hot storage medium 1004 circulates on the set circulation path, so that the liquid phase cold storage of liquid air 1002 energy storage is safe and controllable.

[0047] The present invention also provides a liquid phase cold storage method for liquid air energy storage in the above device, the method comprising the following steps:

[0048] The cold cold storage medium 1003 stored in the cold storage medium storage unit 3 is sent to the cold heat exchanger 1, in which the cold cold storage medium 1003 exchanges heat with the normal temperature air 1001 to obtain the hot cold storage medium 1004 and the liquid air 1002, and the obtained hot cold storage medium 1004 is returned to the cold storage medium storage unit 3;

[0049] The hot cold storage medium 1004 stored in the cold storage medium storage unit 3 is sent to the cold recovery device 2, in which the hot cold storage medium 1004 exchanges heat with the liquid air 1002 to obtain the cold cold storage medium 1003 and the normal temperature air 1001, and the obtained cold cold storage medium 1003 is returned to the cold storage medium storage unit 3.

[0050] In the present invention, the cold storage medium 1003 and the hot storage medium 1004 are stored in the variable temperature tank 101, the low temperature tank 102, and the medium temperature tank 103, and the cold storage medium 1003 and the hot storage medium 1004 are flexibly transported to the cold heat exchanger 1 and the cold recovery device 2 for heat exchange, so that the total volume of the storage tank is greatly reduced compared with the total volume of the storage tank of the traditional cold and hot dual storage tank system, thereby reducing the investment cost.

[0051] According to the present invention, a cold storage medium 1003 is stored in the low temperature tank 102;

[0052] The medium temperature tank 103 stores a hot cold storage medium 1004;

[0053] The temperature-variable tank 101 stores a cold cold storage medium 1003 or a hot cold storage medium 1004 or does not store any medium;

[0054] The volumes of the variable temperature tank 101 , the low temperature tank 102 and the medium temperature tank 103 may be the same or different.

[0055] Preferably, the liquid level of the cold storage medium 1003 stored in the low temperature tank 102 is not lower than the lowest liquid level of the low temperature tank 102;

[0056] The liquid level of the hot cold storage medium 1004 stored in the medium temperature tank 103 is not lower than the lowest liquid level of the medium temperature tank 103;

[0057] When the cold cold storage medium 1003 or the hot cold storage medium 1004 is stored in the temperature change tank 101 , the liquid level of the cold cold storage medium 1003 or the hot cold storage medium 1004 stored in the temperature change tank 101 is not lower than the lowest liquid level of the temperature change tank 101 .

[0058] Preferably, the energy storage process includes the following steps:

[0059] 1) The cold cold storage medium 1003 stored in the temperature-changing tank 101 is preferentially sent to the cold heat exchanger 1, where the cold cold storage medium 1003 exchanges heat with the normal temperature air 1001 to obtain the hot cold storage medium 1004 and the liquid air 1002, and the obtained hot cold storage medium 1004 is returned to the medium temperature tank 103;

[0060] 2) When the cold cold storage medium 1003 is not stored in the temperature-changing tank 101, the cold cold storage medium 1003 stored in the low-temperature tank 102 is sent to the cold heat exchanger 1, where the cold cold storage medium 1003 exchanges heat with the normal temperature air 1001 to obtain the hot cold storage medium 1004 and the liquid air 1002, and the obtained hot cold storage medium 1004 is returned to the temperature-changing tank 101;

[0061] The energy release process includes the following steps:

[0062] 1) The hot cold storage medium 1004 stored in the temperature-variable tank 101 is preferentially sent to the cold recovery device 2, in which the hot cold storage medium 1004 exchanges heat with the liquid air 1002 to obtain the cold cold storage medium 1003 and the normal temperature air 1001, and the obtained cold cold storage medium 1003 is returned to the low temperature tank 102;

[0063] 2) When the hot cold storage medium 1004 is not stored in the temperature-variable tank 101, the hot cold storage medium 1004 stored in the medium-temperature tank 103 is sent to the cold recovery device 2, and the hot cold storage medium 1004 exchanges heat with the liquid air 1002 in the cold recovery device 2 to obtain the cold cold storage medium 1003 and the normal temperature air 1001, and the obtained cold cold storage medium 1003 is returned to the temperature-variable tank 101.

[0064] In the present invention, when the energy storage process is carried out, in the cold heat exchanger 1, the cold cold storage medium 1003 in the temperature variable tank 101 and the low-temperature tank 102 is used for heat exchange in batches, and the hot cold storage medium 1004 after the heat exchange is completed is stored in the temperature variable tank 101 and the medium-temperature tank 103 in batches; when the energy release process is carried out, in the cold recovery device 2, the hot cold storage medium 1004 in the temperature variable tank 101 and the medium-temperature tank 103 is used for heat exchange in batches, and the cold cold storage medium 1003 after the heat exchange is completed is stored in the low-temperature tank 102 and the medium-temperature tank 103 in batches, which not only improves the utilization rate of the temperature variable tank 101, the low-temperature tank 102 and the medium-temperature tank 103, but also makes the empty energy storage and energy release operations more flexible.

[0065] According to the present invention, the energy storage process and the energy release process are not performed at the same time.

[0066] Preferably, when the energy storage process is in progress and the energy release process is stopped, the energy storage process is stopped and the energy release process is started according to the energy storage and release requirements, or the energy storage process is stopped and the energy release process is not started;

[0067] When the energy release process is in progress and the energy storage process is stopped, the energy release process is stopped and the energy storage process is started according to the energy storage release demand, or the energy release process is stopped and the energy storage process is not started;

[0068] When both the energy storage process and the energy release process are stopped, the energy storage process or the energy release process is started according to the energy storage and release requirements, or the energy storage process and the energy release process are not started.

[0069] According to the present invention, both the cold cold storage medium 1003 and the hot cold storage medium 1004 are in liquid state;

[0070] The cold heat exchanger 1 includes at least one heat exchanger. When the number of at least one heat exchanger is more than one, each heat exchanger is connected in parallel, in series, or in a combination of series and parallel.

[0071] The cold recovery device 2 includes at least one recovery device. When the number of the at least one recovery device is more than one, each recovery device is connected in parallel, in series, or in a combination of series and parallel.

[0072] The variable temperature tank 101, the low temperature tank 102 and the medium temperature tank 103 are each independently selected from any one of a spherical tank and a film tank;

[0073] The material of the temperature-changing tank 101 can withstand the temperature change caused by storing the cold cold storage medium 1003 to storing the hot cold storage medium 1004;

[0074] The number of the device is at least one. When the number of the device is more than one, each device is connected in series.

[0075] At least two devices connected in series are used to cool the normal-temperature air into liquid air in stages, and / or to heat the liquid air into normal-temperature air in stages.

[0076] The device in the present invention can be one or at least two connected in series. At least two devices connected in series can cool the room temperature air into liquid air in stages, and / or heat the liquid air to room temperature air in stages. By adjusting the number of devices connected in series, different cold storage and cooling needs can be flexibly adapted.

[0077] The present invention will be described in more detail below through specific embodiments.

[0078] Example 1

[0079] like Figure 1 As shown, this embodiment provides a liquid phase cold storage device for liquid air energy storage, comprising:

[0080] A cold heat exchanger 1 is used to exchange heat between the cold cold storage medium 1003 and the normal temperature air 1001 to obtain the hot cold storage medium 1004 and the liquid air 1002;

[0081] The cold recovery device 2 is used for exchanging heat between the hot cold storage medium 1004 and the liquid air 1002 to obtain the cold cold storage medium 1003 and the normal temperature air 1001;

[0082] The cold storage medium storage unit 3 is used to deliver the stored cold cold storage medium 1003 to the cold heat exchanger 1 and receive the hot cold storage medium 1004 returned by the cold heat exchanger 1; and to deliver the stored hot cold storage medium 1004 to the cold recovery device 2 and receive the cold cold storage medium 1003 returned by the cold recovery device 2;

[0083] The cold heat exchanger 1 is provided with a normal temperature air inlet, a liquid air outlet, a first low temperature medium inlet, a second low temperature medium inlet, a first high temperature medium outlet, and a second high temperature medium outlet;

[0084] The cold recovery device 2 is provided with a normal temperature air outlet, a liquid air inlet, a first high temperature medium inlet, a second high temperature medium inlet, a first low temperature medium outlet, and a second low temperature medium outlet;

[0085] The cold storage medium storage unit 3 includes a variable temperature tank 101, a low temperature tank 102 and a medium temperature tank 103;

[0086] The first low-temperature medium outlet is connected to the first low-temperature medium inlet via the low-temperature tank 102;

[0087] The first high temperature medium outlet is connected to the first high temperature medium inlet via the medium temperature tank 103;

[0088] The second low-temperature medium inlet, the second high-temperature medium outlet, the second high-temperature medium inlet, and the second low-temperature medium outlet are all connected to the temperature-changing tank 101;

[0089] The cold storage medium 1003 in the cold heat exchanger 1 flows in the opposite direction to the normal temperature air 1001;

[0090] The hot cold storage medium 1004 and the liquid air 1002 in the cold recovery device 2 flow in opposite directions;

[0091] The outlet pipelines of the variable temperature tank 101, the low temperature tank 102 and the medium temperature tank 103 are provided with respective independent circulation pumps (not shown) and switch valves (not shown);

[0092] The circulation pump (not shown) and the switch valve (not shown) are used to control the circulation flow of the cold storage medium 1003 and / or the hot storage medium 1004 on a set circulation path.

[0093] In this embodiment, the variable temperature tank 101, the medium temperature tank 103, and the low temperature tank 102 are all spherical tanks, wherein the material of the variable temperature tank 101 can withstand the temperature change caused by storing the cold storage medium 1003 to the hot storage medium 1004;

[0094] The cold heat exchanger 1 is two air precoolers connected in series;

[0095] The cold recovery device 2 is two cryogenic recovery devices connected in series.

[0096] This embodiment provides a liquid phase cold storage and cold utilization method for liquid air energy storage, in which the liquid air 1002 energy storage can be divided into an energy storage process and an energy release process, wherein the process in which the normal temperature air 1001 in the energy storage process and the cold cold storage medium 1003 are heat exchanged, cooled and liquefied in the cold heat exchanger 1 is called the cold utilization process; the process in which the low temperature liquid air 1002 in the energy release process and the hot cold storage medium 1004 are heat exchanged and the cold is recovered in the cold recovery device 2 is called the cold storage process;

[0097] The operation mode of the cold process is:

[0098] 1) Before the cold heat exchanger 1 is used for heat exchange, the device is in a complete cold storage state, that is, all the cold storage medium is the cold storage medium 1003, all the cold storage medium 1003 is stored in the variable temperature tank 101 and the low temperature tank 102 respectively, and the medium temperature tank 103 is in a high temperature hollow state;

[0099] 2) When the heat exchange with the cold heat exchanger 1 starts, the variable temperature tank 101 first delivers the cold storage tank medium to the cold heat exchanger 1 for heat exchange with the normal temperature air 1001, and the hot cold storage medium 1004 obtained after the heat exchange is stored in the previously high temperature hollow medium temperature tank 103;

[0100] 3) As the energy storage process proceeds, the cold cold storage medium 1003 in the temperature-changing tank 101 continues to exchange heat, and the cold cold storage medium 1003 in the temperature-changing tank 101 is completely converted into the hot cold storage medium 1004 and transported to the medium-temperature tank 103 for storage. At this time, the volume of the temperature-changing tank 101 is vacated, and it can be used to receive the hot cold storage medium 1004 from the self-use cold heat exchanger 1, and the cold loss due to the mixing of the cold and hot cold storage media 1004 can be ignored;

[0101] 4) The low temperature tank 102 storing the cold cold storage medium 1003 starts to provide the cold cold storage medium 1003 to the cold heat exchanger 1 for heat exchange with the normal temperature air 1001;

[0102] 5) As the energy storage process proceeds, the cold storage medium 1003 in the low temperature tank 102 continuously exchanges heat and is converted into the hot storage medium 1004 and stored in the previously emptied temperature-variable tank 101. After the cold process is completed, the cold storage medium 1003 has been completely converted into the hot storage medium 1004 and stored in the temperature-variable tank 101 and the medium temperature tank 103, and the volume of the low temperature tank 102 is emptied;

[0103] The operation mode of the cold storage process is:

[0104] 1) The temperature-variable tank 101 preferentially provides the hot cold storage medium 1004 stored therein to the cold recovery device 2, and exchanges heat with the liquid air 1002 in the cold recovery device 2 to recover the cold energy in the liquid air 1002. After the heat exchange, the obtained cold cold storage medium 1003 is stored in the empty low-temperature tank 102 at the end of the cold process;

[0105] 2) As the energy release process proceeds, the hot cold storage medium 1004 in the temperature-changing tank 101 continues to exchange heat, and the hot cold storage medium 1004 in the temperature-changing tank 101 is completely converted into the cold cold storage medium 1003 and transported and stored in the low-temperature tank 102. The volume of the temperature-changing tank 101 is vacated, and it can be used to receive the cold cold storage medium 1003 from the cold recovery device 2, and the cold loss due to the mixing of the hot and cold cold storage medium 1004 can be ignored;

[0106] 3) The medium temperature tank 103 storing the hot cold storage medium 1004 starts to provide the hot cold storage medium 1004 to the cold recovery device 2 for heat exchange with the liquid air 1002;

[0107] 4) As the energy release process proceeds, the hot cold storage medium 1004 is continuously converted into the cold cold storage medium 1003 by heat exchange and stored in the previously emptied temperature-variable tank 101. After the cold storage process is completed, the hot cold storage medium 1004 has been completely converted into the cold cold storage medium 1003 and stored in the temperature-variable tank 101 and the low-temperature tank 102, and the volume of the medium-temperature tank 103 is emptied.

[0108] In this embodiment, in a cold use and cold storage cycle, the low-temperature tank 102 is always used to store cold cold storage medium 1003 while the medium-temperature tank 103 is always used to store hot cold storage medium 1004; the variable temperature tank 101 completes the conversion from storing cold cold storage medium 1003 to storing hot cold storage medium 1004 in the cold use process, and completes the conversion from storing hot cold storage medium 1004 to storing cold cold storage medium 1003 in the cold storage process. The variable temperature tank 101 can be used as a low-temperature tank 102 and a medium-temperature tank 103 at the same time.

[0109] In this embodiment, the cold storage and cold utilization processes are carried out according to the actual needs of the liquid-air energy storage process. The heat exchange speed can be adjusted according to the storage and release fluctuations of the liquid-air energy storage. The cold storage and cold utilization processes can also be freely switched at any time during the heat exchange process according to the actual storage and release needs of the liquid-air energy storage, thereby meeting the actual needs of the liquid-air energy storage process in the energy storage and release processes.

[0110] In this embodiment, by setting up cold storage medium 1003 and hot storage medium 1004 for efficient transfer and utilization between the cold heat exchanger 1, the cold recovery device 2 and the cold storage medium storage unit 3, the shortcomings of the traditional cold storage system such as large storage tank volume and high investment are improved, thereby improving the economic benefits of liquid air 1002 energy storage.

[0111] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A liquid phase cold storage device for liquid air energy storage, characterized in that: include: A cold heat exchanger is used to exchange heat between the cold storage medium and the normal temperature air to obtain the hot storage medium and liquid air; A cold recovery device, used for exchanging heat between the hot cold storage medium and the liquid air to obtain the cold cold storage medium and the normal temperature air; A cold storage medium storage unit, used for delivering the stored cold cold storage medium to the cold heat exchanger, and receiving the hot cold storage medium returned by the cold heat exchanger; The device is used to deliver the stored hot cold storage medium to the cold recovery device and receive the cold cold storage medium returned by the cold recovery device.

2. The device according to claim 1, characterized in that The cold heat exchanger is provided with a normal temperature air inlet, a liquid air outlet, a first low temperature medium inlet, a second low temperature medium inlet, a first high temperature medium outlet, and a second high temperature medium outlet; The cold recovery device is provided with a normal temperature air outlet, a liquid air inlet, a first high temperature medium inlet, a second high temperature medium inlet, a first low temperature medium outlet, and a second low temperature medium outlet; The cold storage medium storage unit includes a variable temperature tank, a low temperature tank and a medium temperature tank; The first low-temperature medium outlet is connected to the first low-temperature medium inlet via the low-temperature tank; The first high temperature medium outlet is connected to the first high temperature medium inlet via the medium temperature tank; The second low-temperature medium inlet, the second high-temperature medium outlet, the second high-temperature medium inlet, and the second low-temperature medium outlet are all connected to the temperature-changing tank.

3. The device according to claim 2, characterized in that The cold storage medium in the cold heat exchanger flows in the opposite direction to the normal temperature air; The hot cold storage medium in the cold recovery device flows in the opposite direction to the liquid air; The outlet pipelines of the variable temperature tank, low temperature tank and medium temperature tank are provided with independent circulation pumps and switch valves; The circulation pump and the switch valve are used to control the cold storage medium and / or the hot storage medium to circulate on a set circulation path.

4. A liquid phase cold storage method for liquid air energy storage in the device according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: Energy storage process: The cold cold storage medium stored in the cold storage medium storage unit is sent to the cold heat exchanger, in which the cold cold storage medium exchanges heat with the normal temperature air to obtain hot cold storage medium and liquid air, and the obtained hot cold storage medium is returned in whole or in part to the cold storage medium storage unit; Energy release process: The hot cold storage medium stored in the cold storage medium storage unit is sent to the cold recovery device, in which the hot cold storage medium exchanges heat with liquid air to obtain cold cold storage medium and room temperature air, and all or part of the obtained cold cold storage medium is returned to the cold storage medium storage unit.

5. The method according to claim 4, characterized in that The cold storage medium is stored in the low temperature tank; The hot cold storage medium is stored in the medium temperature tank; The temperature-variable tank stores the cold storage medium or the hot storage medium or does not store any medium; The volumes of the variable temperature tank, low temperature tank and medium temperature tank are the same or different.

6. The method according to claim 5, characterized in that The liquid level of the cold storage medium stored in the low temperature tank is not lower than the lowest liquid level of the low temperature tank; The liquid level of the hot cold storage medium stored in the medium temperature tank is not lower than the lowest liquid level of the medium temperature tank; When the cold cold storage medium or the hot cold storage medium is stored in the temperature-changing tank, the liquid level of the cold cold storage medium or the hot cold storage medium stored in the temperature-changing tank is not lower than the lowest liquid level of the temperature-changing tank.

7. The method according to claim 6, characterized in that The energy storage process comprises the following steps: 1) The cold storage medium stored in the variable temperature tank is preferentially sent to the cold heat exchanger, where the cold storage medium exchanges heat with the normal temperature air to obtain the hot storage medium and liquid air, and the obtained hot storage medium is returned to the medium temperature tank; 2) When the cold storage medium is not stored in the temperature-changing tank, the cold storage medium stored in the low-temperature tank is sent to the cold heat exchanger, where the cold storage medium exchanges heat with the normal temperature air to obtain the hot storage medium and liquid air, and the obtained hot storage medium is returned to the temperature-changing tank; The energy release process comprises the following steps: 1) The hot cold storage medium stored in the temperature-variable tank is preferentially sent to the cold recovery device, where the hot cold storage medium exchanges heat with liquid air to obtain cold cold storage medium and normal temperature air, and the obtained cold cold storage medium is returned to the low-temperature tank; 2) When the hot cold storage medium is not stored in the variable temperature tank, the hot cold storage medium stored in the medium temperature tank is sent to the cold recovery device, in which the hot cold storage medium exchanges heat with liquid air to obtain cold cold storage medium and room temperature air, and the obtained cold cold storage medium is returned to the variable temperature tank.

8. The method according to claim 7, characterized in that The energy storage process and the energy release process are not performed at the same time.

9. The method according to claim 8, characterized in that When the energy storage process is in progress and the energy release process is stopped, according to the energy storage and release requirements, the energy storage process is stopped and the energy release process is started, or the energy storage process is stopped and the energy release process is not started; When the energy release process is in progress and the energy storage process is stopped, according to the energy storage and release requirements, the energy release process is stopped and the energy storage process is started, or the energy release process is stopped and the energy storage process is not started; When both the energy storage process and the energy release process are stopped, the energy storage process or the energy release process is started according to the energy storage and release requirements, or the energy storage process or the energy release process is not started.

10. The method according to claim 9, characterized in that The cold storage medium and the hot storage medium are both in liquid state; The cold heat exchanger includes at least one heat exchanger. When the number of the at least one heat exchanger is more than one, each heat exchanger is connected in parallel, in series, or in a combination of series and parallel. The cold recovery device includes at least one recovery device. When the number of the at least one recovery device is more than one, each recovery device is connected in parallel, in series, or in a combination of series and parallel. The variable temperature tank, low temperature tank and medium temperature tank are independently selected from any one of a spherical tank and a film tank; The material of the temperature-changing tank can withstand the temperature change from storing cold cold storage medium to storing hot cold storage medium; The number of the device is at least one. When the number of the device is more than one, each device is connected in series. At least two devices connected in series are used to cool the normal-temperature air into liquid air in stages, and / or to heat the liquid air into normal-temperature air in stages.

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