Cold storage subsystem and method for recycling, storing and utilizing cold energy in liquid air through cold storage subsystem

Abstract

The embodiment of the invention provides a cold storage subsystem and a method for recycling, storing and utilizing cold energy in liquid air through the cold storage subsystem. During cold accumulation, an outlet of a circulating fan in the cold accumulation subsystem is connected with a cold carrying medium inlet of an evaporator, a cold carrying medium outlet of the evaporator is connected with a first inlet and outlet of a cold accumulation medium storage tank unit, and a second inlet and outlet of the cold accumulation medium storage tank unit is connected with an inlet of the circulating fan; during cold release, a cold carrying medium outlet of the cold box is connected with an inlet of the circulating fan, an outlet of the circulating fan is further connected with a second inlet and outlet of the cold storage medium storage tank unit, and a first inlet and outlet of the cold storage medium storage tank unit is connected with a cold carrying medium inlet of the cold box; a pressure supplementing pipe is arranged between the liquid air storage tank and the liquid air inlet of the evaporator and connected with the second inlet and outlet of the cold storage medium storage tank unit. According to the system, the pressure loss in the operation of the cold storage subsystem can be reduced, meanwhile, the cold energy storage grade is preserved, and the temperature loss is controlled to be 1-2 DEG C.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid air energy storage, and in particular to a cold storage subsystem and a method for recovering, storing and utilizing cold energy in liquid air by using the cold storage subsystem. Background Art

[0002] New energy sources have experienced rapid development. New energy sources such as wind and solar have large load fluctuations, and the power system needs the support of energy storage technology. Compressed air energy storage, as a new type of energy storage technology, can realize the consumption of renewable energy, peak shaving and valley filling, and support the stability of the power grid, and is receiving widespread attention. Liquid air energy storage technology (LAES) is derived from compressed air energy storage technology. It improves the gas storage method and enhances the flexibility of the energy storage system. Compared with traditional compressed air energy storage systems, it has the advantages of being independent of geographical conditions and having high energy storage density. It greatly improves the deficiency of large volume required for storing compressed air at room temperature, has the characteristics of long time and large capacity, and has comprehensive performance, flexible site selection, safety and reliability, and can provide rotational inertia. These characteristics make liquefied air energy storage have a variety of application scenarios and are easy to configure in various scenarios on the power generation side, the grid side, and the user side.

[0003] In addition to changing the storage state of air, the liquid air energy storage system also adds an energy recovery subsystem. The cold storage subsystem is one of the two major subsystems, and its main function is to realize the cold energy recovery in the power generation process and the cold energy utilization in the power storage process of the liquid air energy storage system. In large-scale engineering projects, there will be several or even dozens of cold storage containers in the cold storage subsystem of the liquid air energy storage system. The arrangement and insulation method of the cold storage containers and the control method of cold energy storage and release directly affect the cold energy storage quality and efficiency of the cold storage subsystem, and thus affect the overall utilization efficiency of the liquid air energy storage system. Summary of the invention

[0004] The purpose of the present invention includes providing a cold storage subsystem and a method for recovering, storing and utilizing cold energy in liquid air using the cold storage subsystem, which can effectively reduce the pressure loss during the operation of the cold storage subsystem.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] In a first aspect, the present invention provides a cold storage subsystem, comprising a circulating fan, a cold storage medium tank unit, an evaporator for heat exchange between liquid air and a high-temperature cold medium, and a cold box for absorbing cold energy in a low-temperature cold medium, wherein;

[0007] The outlet of the circulation fan is connected to the cold medium inlet of the evaporator, the cold medium outlet of the evaporator is connected to the first inlet and outlet of the cold storage medium tank unit, and the second inlet and outlet of the cold storage medium tank unit is connected to the inlet of the circulation fan;

[0008] The outlet of the cold box is connected to the inlet of the circulating fan, the outlet of the circulating fan is also connected to the second inlet and outlet of the cold storage medium tank unit, and the first inlet and outlet of the cold storage medium tank unit is connected to the inlet of the cold box;

[0009] The liquid air inlet of the evaporator is connected to a liquid air storage tank, a pressure compensation pipe is provided between the liquid air storage tank and the liquid air inlet of the evaporator, and the pressure compensation pipe is connected to the second inlet and outlet of the cold storage medium storage tank unit.

[0010] In an optional embodiment, a constant pressure pump is provided on the liquid air pressure compensation pipe.

[0011] In an optional embodiment, the cold storage medium storage tank unit includes n cold storage medium storage tank groups connected in series, each of the cold storage medium storage tank groups includes more than two cold storage medium storage tanks, wherein n is an integer greater than or equal to 2;

[0012] Each of the cold storage medium tank groups includes a first inlet and outlet of the cold storage medium tank group connected to the first inlet and outlet of each of the cold storage medium tanks in the group and a second inlet and outlet of the cold storage medium tank group connected to the second inlet and outlet of each of the cold storage medium tanks in the group, the first inlet and outlet of the nth cold storage medium tank group is the first inlet and outlet of the cold storage medium tank unit, and the second inlet and outlet of the first cold storage medium tank group is the second inlet and outlet of the cold storage medium tank unit;

[0013] Each of the cold storage medium tank groups further includes a connecting pipe connected between the first inlet and outlet of the corresponding cold storage medium tank group and the second inlet and outlet of the corresponding cold storage medium tank group, and each of the connecting pipes is provided with a valve.

[0014] In an optional embodiment, the cold storage medium tanks in the cold storage medium tank unit are arranged in a rectangular array.

[0015] In an optional embodiment, the cold storage medium storage tank unit includes a mother tank, the mother tank includes an inner tank body and an outer tank body, and the cold storage medium storage tanks in the cold storage medium storage tank unit are arranged in a circular array between the inner tank body and the outer tank body with the axis of the mother tank as the axis.

[0016] In an optional embodiment, a heat-insulating filling material is provided between two adjacent cold storage medium tanks;

[0017] And / or, a filter is provided between the first inlet and outlet of the cold storage medium tank unit and the cold medium inlet of the cold box;

[0018] And / or, a filter is provided between the second inlet and outlet of the cold storage medium tank unit and the inlet of the circulation fan.

[0019] In a second aspect, the present invention provides a method for recovering, storing and utilizing cold energy in liquid air using the cold storage subsystem described in any one of the aforementioned embodiments, comprising:

[0020] Cold storage: using a circulating fan to drive the cooling medium to first recover the cold energy generated by the evaporation of liquid air through the evaporator, and then store the cold energy in the cold storage medium tank through the cold storage medium;

[0021] To release the cold, the circulating fan is used to drive the cold medium to first pass through the cold storage medium tank to absorb the cold energy stored therein, and then release the absorbed cold energy through the cold box.

[0022] In an optional embodiment, cold storage comprises the following steps:

[0023] The cooling medium that has passed through the evaporator first passes through the i-th cooling medium storage tank group and the i-1-th cooling medium storage tank group in sequence, and then passes through the circulating fan;

[0024] When the i-th cold storage medium storage tank group has completed cold storage, the valve on the connecting pipe corresponding to the i-th cold storage medium storage tank group is opened, and the valve on the inlet and outlet of the cold storage medium storage tank corresponding to the i-th cold storage medium storage tank group is closed; when the temperature of the second inlet and outlet of the i-1-th cold storage medium storage tank group is lower than the temperature of the second inlet and outlet of the corresponding cold storage medium storage tank group when no cold medium passes through, the cold medium flowing out of the i-1-th cold storage medium storage tank group passes through the i-2-th cold storage medium storage tank group and then passes through the circulating fan;

[0025] After the second cold storage medium storage tank group has completed cold storage, the valve on the connecting pipe corresponding to the second cold storage medium storage tank group is opened, and the valve on the inlet and outlet of the cold storage medium storage tank corresponding to the second cold storage medium storage tank group is closed;

[0026] After the fan inlet temperature reaches a preset value C or the duration of the cold storage step reaches a preset duration D, the fan and the inlet and outlet valves of the cold storage medium storage tank corresponding to the first cold storage medium storage tank group are closed;

[0027] Wherein, 3≤i≤n, and i is an integer.

[0028] In an optional embodiment, in the cold release step, the cold medium that has passed through the circulating fan first passes through the jth cold storage medium storage tank group and the j+1th cold storage medium storage tank group in sequence and then passes through the cold box;

[0029] After the cold storage medium storage tank group of the jth cold storage medium storage tank group has been released, the valve on the connecting pipe corresponding to the jth cold storage medium storage tank group is opened, and the valve on the cold storage medium storage tank inlet and outlet corresponding to the jth cold storage medium storage tank group is closed; when the temperature of the first inlet and outlet of the j+1th cold storage medium storage tank group is higher than the temperature of the first inlet and outlet of the corresponding cold storage medium storage tank group when no cold medium passes through, the cold medium flowing out of the j+1th cold storage medium storage tank group passes through the circulation fan after passing through the j+2th cold storage medium storage tank group;

[0030] After the n-1th cold storage medium storage tank group has finished releasing cold, the valve on the connecting pipe corresponding to the n-1th cold storage medium storage tank group is opened, and the valve on the inlet and outlet of the cold storage medium storage tank corresponding to the n-1th cold storage medium storage tank group is closed;

[0031] After the fan inlet temperature reaches a preset value E or the duration of the cooling step reaches a preset duration F, the fan and the inlet and outlet valves of the cold storage medium storage tank corresponding to the nth cold storage medium storage tank group are closed;

[0032] Wherein, 1≤j≤n-2, and j is an integer.

[0033] In an optional embodiment, when the temperature of the cooling medium leaving the cooling medium outlet of the evaporator is higher than a preset value A, the circulation fan flow rate is reduced; when the temperature of the cooling medium leaving the cooling medium outlet of the evaporator is lower than the preset value A, the circulation fan flow rate is increased;

[0034] And / or, if the evaporator thermal pressure drop is greater than the preset value B, the system alarms.

[0035] The cold storage subsystem provided by the embodiment of the present invention and the method for recovering, storing and utilizing cold energy in liquid air using the cold storage subsystem have the following beneficial effects:

[0036] The number of series and parallel cold storage tanks can be controlled and switched according to the calculation of the inclined temperature layer and the cold storage time, which can effectively reduce the pressure loss during the operation of the cold storage subsystem, while preserving the cold energy storage quality and controlling the temperature loss to 1-2°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A process flow chart of the cold storage subsystem provided for this embodiment;

[0039] Figure 2 A schematic diagram of a structure of a cold storage medium tank unit provided in this embodiment (A1-A5 and B1-B5 both represent cold storage medium tanks);

[0040] Figure 3 Another structural schematic diagram of the cold storage medium tank unit provided for this embodiment (A1-A5 and B1-B5 both represent cold storage medium tanks).

[0041] Icons: 100-circulating fan; 200-cold storage medium tank unit; 210-cold storage medium tank; 220-mother tank; 221-inner tank body; 222-outer tank body; 300-connecting pipe; 400-evaporator; 500-cold box; 600-liquid air pressure boosting pipe; 610-constant pressure pump; 700-filter; 800-cryogenic pump. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0045] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0046] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0047] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0048] The embodiment of the present invention provides a cold storage subsystem, specifically as follows Figure 1 As shown, it includes a circulating fan 100, a cold storage medium tank unit 200, an evaporator 400 for heat exchange between liquid air and high-temperature cold medium, and a cold box 500 for absorbing cold energy in the low-temperature cold medium, wherein;

[0049] The outlet of the circulating fan 100 is connected to the cold medium inlet of the evaporator 400, the cold medium outlet of the evaporator 400 is connected to the first inlet and outlet of the cold storage medium tank unit 200, and the second inlet and outlet of the cold storage medium tank unit 200 is connected to the inlet of the circulating fan 100;

[0050] The outlet of the cold box 500 for the cooling medium is connected to the inlet of the circulating fan 100, and the outlet of the circulating fan 100 is also connected to the second inlet and outlet of the cold storage medium tank unit 200, and the first inlet and outlet of the cold storage medium tank unit 200 is connected to the inlet of the cold box 500 for the cooling medium;

[0051] The liquid air inlet of the evaporator is connected to a liquid air storage tank. A pressure compensation pipe 600 is provided between the liquid air storage tank and the liquid air inlet of the evaporator 400 . The pressure compensation pipe 600 is connected to the second inlet and outlet of the cold storage medium storage tank unit 200 .

[0052] The cold storage subsystem mainly includes the evaporator 400, the circulating fan 100, the cold box 500 and the cold storage medium tank 210, wherein the cold medium used can be selected as needed, for example, pure dry air can be selected. In the cold storage subsystem, the evaporator 400 is used for heat exchange between pure air and liquid air, the circulating fan 100 is used to drive the pressurized pure air to operate in the subsystem for normal heat exchange, the cold box 500 is used for heat exchange between low-temperature pure air and normal-temperature air, and the liquid air pressure-compensating pipe 600 can be used for liquid air pressure-compensating to compensate for the pressure loss after passing through the cold storage medium tank 210, thereby reducing the energy consumption of the circulating fan 100.

[0053] The energy storage operating temperature range of the system is -160°C to room temperature, and the medium circulation pressure can be 0.8MPa to 2.0MPa, which is conducive to reducing the circulation power consumption. The solid particles used as the cold energy storage medium in the cold storage medium tank 210 of the present invention include but are not limited to pebbles, basalt, marble, etc.

[0054] It should be noted that the high temperature and low temperature in the high-temperature cooling medium and the low-temperature cooling medium in the present application are relative temperatures, which only means that the temperature of the high-temperature cooling medium is greater than the temperature of the low-temperature cooling medium; the inlets and outlets involved can be used for the inflow of cooling medium or for the outflow of cooling medium according to the purpose of system operation.

[0055] In an optional implementation, a constant pressure pump 610 is provided on the liquid air pressure compensation pipe 600 .

[0056] In an optional embodiment, the cold storage medium tank unit 200 includes n cold storage medium tank groups connected in series, each of which includes more than two cold storage medium tanks 210, where n is an integer greater than or equal to 2;

[0057] Each of the cold storage medium tank groups includes a first inlet and outlet of the cold storage medium tank group connected to the first inlet and outlet of each of the cold storage medium tanks 210 in the group and a second inlet and outlet of the cold storage medium tank group connected to the second inlet and outlet of each of the cold storage medium tanks 210 in the group, the first inlet and outlet of the nth cold storage medium tank group is the first inlet and outlet of the cold storage medium tank unit 200, and the second inlet and outlet of the first cold storage medium tank group is the second inlet and outlet of the cold storage medium tank unit 200;

[0058] Each of the cold storage medium tank groups further includes a connecting pipe 300 connected between the first inlet and outlet of the corresponding cold storage medium tank group and the second inlet and outlet of the corresponding cold storage medium tank group, and each of the connecting pipes 300 is provided with a valve.

[0059] In the implementation mode of the present application, the cold storage capacity of a single cold storage medium storage tank 210 can be 6-30MWh, and multiple cold storage medium storage tanks 210 work together to complete the energy storage and energy release tasks. In addition to the inconvenience of on-site installation, a large-capacity cold storage medium storage tank 210 is also prone to poor temperature uniformity and a large thickness of the inclined temperature layer during operation, which will directly lead to a decrease in the cold storage quality and efficiency. The implementation mode of the present application selects to use multiple small cold storage medium storage tanks 210 to improve or even avoid the problems of poor temperature uniformity and a large thickness of the inclined temperature layer of a single large cold storage medium storage tank 210. The present invention does not select all tanks to be simply connected in series in a main path in an end-to-end manner, but rather to perform series and parallel combinations according to objective conditions such as quantity and operating time, so that the temperature of the cold storage medium storage tanks 210 in the same cold storage medium storage tank group remains consistent, and at the same time, the pressure drop is controlled within a certain range, which can maximize the retention of the cold storage quality and improve the subsystem operation efficiency to meet the design requirements of the cold storage subsystem.

[0060] In an optional embodiment, the cold storage medium tanks 210 in the cold storage medium tank unit 200 are arranged in a rectangular array.

[0061] In an optional embodiment, the cold storage medium storage tank unit 200 includes a mother tank 220, and the mother tank 220 includes an inner tank body 221 and an outer tank body 222. The cold storage medium storage tanks 210 in the cold storage medium storage tank unit 200 are arranged in a circular array between the inner tank body 221 and the outer tank body 222 with the axis of the mother tank 220 as the axis.

[0062] The design direction of the cold storage medium storage tank 210 tank area layout is to reasonably plan the use space and reduce the cold energy loss caused by the temperature difference with the ambient temperature during storage. The present invention provides two ways of arranging the cold storage medium storage tank 210, one is the mother-child tank 220 form (the cold storage medium storage tanks 210 in the cold storage medium storage tank unit 200 are arranged in a ring array with the axis of the mother tank 220 as the axis), and the other is a single tank insulation form (the cold storage medium storage tanks 210 in the cold storage medium storage tank unit 200 are arranged in a rectangular array).

[0063] Among them, due to its special insulation form, the mother-child tank 220 can reduce heat conduction and reduce cold loss to a greater extent. However, due to certain limitations of the mother-child tank 220 in terms of the use space, the mother-child tank 220 form has certain requirements on the number of cold storage medium tanks 210. The number of cold storage medium tanks 210 in a single mother-child tank 220 is generally no more than 6. If the use space is limited, it is recommended to design multiple mother-child tanks 220; the single tank insulation form has fewer restrictions on spatial layout and more flexible arrangement, but the single tank insulation design is weaker than the mother-child tank 220 in terms of cold energy preservation. Taking 10 cold storage medium tanks 210 as an example, the specific layout design is as follows: Figure 2 and Figure 3 shown.

[0064] It should be noted that, whether the cold storage medium storage tank 210 adopts the form of a mother tank 220 or a single tank insulation form, it only refers to the arrangement of the cold storage medium storage tank 210 rather than the connection method. Figure 1 way to connect.

[0065] In an optional embodiment, a thermal insulation filling material is provided between two adjacent cold storage medium tanks 210;

[0066] And / or, a filter 700 is provided between the inlet of the cold storage medium tank unit 200 and the cold medium inlet of the cold box 500;

[0067] And / or, a filter 700 is disposed between the outlet of the cold storage medium tank unit 200 and the inlet of the circulation fan 100 .

[0068] The air after cold storage and cold release enters the filter 700 to filter out impurities and reduce the impact on subsequent equipment;

[0069] The embodiment of the present invention further provides a method for recovering, storing and utilizing cold energy in liquid air using the cold storage subsystem described in any one of the aforementioned embodiments, comprising:

[0070] Cold storage, using the circulating fan 100 to drive the cooling medium to first recover the cold energy generated by the evaporation of liquid air through the evaporator 400, and then store the cold energy in the cold storage medium tank 210 through the cold storage medium;

[0071] To release the cold, the circulating fan 100 is used to drive the cold medium to first pass through the cold storage medium tank 210 to absorb the cold energy stored therein, and then release the absorbed cold energy through the cold box 500.

[0072] The energy storage operating temperature range of the system is -160℃ to room temperature, and the medium circulation pressure can be 0.8MPa to 2.0MPa, which is conducive to reducing the circulation power consumption.

[0073] In the implementation mode of the present application, the circulating fan 100 is used to drive the normal temperature air, and the cold energy generated by the evaporation of the liquid air is recovered through the evaporator 400 and stored in the liquid-air cold storage medium storage tank 210; the cold release unit uses the circulating fan 100 to use the normal temperature air as the heat transfer medium, and takes out high-quality cold energy through the liquid-air cold storage medium storage tank 210, and inputs it into the cold box 500 as the external cold source of the air liquefaction subsystem for air liquefaction on the power storage side. The cold storage and cold release circulating fans 100 used in the present invention are in a common mode, and the two modes of operation are realized by switching the valve, which can reduce the system investment cost and maintenance cost.

[0074] In an optional embodiment, cold storage comprises the following steps:

[0075] The cooling medium that has passed through the evaporator 400 first passes through the i-th cooling medium storage tank group and the i-1-th cooling medium storage tank group in sequence, and then passes through the circulating fan 100;

[0076] When the i-th cold storage medium storage tank group has completed cold storage, the valve on the connecting pipe 300 corresponding to the i-th cold storage medium storage tank group is opened, and the valve on the inlet and outlet of the cold storage medium storage tank 210 corresponding to the i-th cold storage medium storage tank group is closed; when the temperature of the second inlet and outlet of the i-1-th cold storage medium storage tank group is lower than the temperature of the second inlet and outlet of the corresponding cold storage medium storage tank group when no cold medium passes through, the cold medium flowing out of the i-1-th cold storage medium storage tank group passes through the i-2-th cold storage medium storage tank group and then passes through the circulating fan 100;

[0077] After the second cold storage medium storage tank group has completed cold storage, the valve on the connecting pipe 300 corresponding to the second cold storage medium storage tank group is opened, and the valve on the inlet and outlet of the cold storage medium storage tank 210 corresponding to the second cold storage medium storage tank group is closed;

[0078] After the fan inlet temperature reaches a preset value C or the duration of the cold storage step reaches a preset duration D, the fan and the inlet and outlet valves of the cold storage medium storage tank 210 corresponding to the first cold storage medium storage tank group are closed;

[0079] Wherein, 3≤i≤n, and i is an integer.

[0080] In an optional embodiment, in the cold release step, the cold medium that has passed through the circulating fan 100 first passes through the jth cold storage medium storage tank group and the j+1th cold storage medium storage tank group in sequence and then passes through the cold box 500;

[0081] After the cold storage medium storage tank group of the jth cold storage medium storage tank group has been released, the valve on the connecting pipe 300 corresponding to the jth cold storage medium storage tank group is opened, and the valve on the inlet and outlet of the cold storage medium storage tank 210 corresponding to the jth cold storage medium storage tank group is closed; when the temperature of the first inlet and outlet of the j+1th cold storage medium storage tank group is higher than the temperature of the first inlet and outlet of the corresponding cold storage medium storage tank group when no cold medium passes through, the cold medium flowing out of the j+1th cold storage medium storage tank group passes through the circulation fan 100 after passing through the j+2th cold storage medium storage tank group;

[0082] After the n-1th cold storage medium storage tank group has finished releasing cold, the valve on the connecting pipe 300 corresponding to the n-1th cold storage medium storage tank group is opened, and the valve on the inlet and outlet of the cold storage medium storage tank 210 corresponding to the n-1th cold storage medium storage tank group is closed;

[0083] After the fan inlet temperature reaches the preset value E or the duration of the cooling step reaches the preset duration F, the fan and the inlet and outlet valves of the cold storage medium tank 210 corresponding to the nth cold storage medium tank group are closed; wherein 1≤j≤n-2, and j is an integer.

[0084] In an optional embodiment, when the temperature of the cooling medium leaving the cooling medium outlet of the evaporator 400 is higher than the preset value A, the flow rate of the circulating fan 100 is reduced; when the temperature of the cooling medium leaving the cooling medium outlet of the evaporator 400 is lower than the preset value A, the flow rate of the circulating fan 100 is increased;

[0085] And / or, if the thermal pressure drop of the evaporator 400 is greater than a preset value B, the system alarms.

[0086] The cold storage subsystem in the embodiment of the present invention takes 10 cold storage medium storage tanks 210 as an example (only 10 cold storage medium storage tanks 210 are taken as an example, and the present invention does not limit the number of cold storage medium storage tanks 210). Figure 1 As shown, the cold storage medium tank unit 200 adopts a 5-series-2-parallel combination mode, which is respectively the 1st row, the 2nd row to the 5th row from top to bottom, and the 1st column and the 2nd column from left to right; and the cold storage medium tank unit 200 has a main pipeline for collecting clean air after cold storage / release, and the main pipeline is composed of five connecting pipes 300 connected, each of which is provided with a valve, and there are 5 valves (valves 1-5) to complete the series-parallel switching of the cold storage medium tank unit 200. The inlet temperature of the circulating fan 100 can be not less than -10°C, thereby reducing the difficulty and price of the circulating fan 100 selection.

[0087] (1) Cold storage

[0088] Liquid air enters the evaporator 400 through the cryogenic pump 800 for evaporation and vaporization. Normal temperature air driven by the cold storage system circulating fan 100 as a cooling medium enters the evaporator 400 to absorb cold energy, and the absorbed cold energy is recovered to the cold storage medium tank 210 for storage. The system circulating medium uses clean air, which passes through the evaporator 400 so that the liquid air at not less than -165°C exchanges heat with the clean air at not more than 25°C. When the clean air flows out from the cold end of the evaporator 400, the temperature drops to not less than -160°C, and then prepares for cold energy storage; when the clean air outlet temperature is higher than -160°C, the fan flow rate is reduced; when the clean air outlet temperature is lower than -160°C, the circulation fan 100 flow rate is increased. The normal operation of the thermal pressure drop of the evaporator 400 is 20-25KPa. If the pressure drop increases to 30KPa, the system alarms.

[0089] Before the low-temperature air flowing out of the cold end of the evaporator 400 enters the cold storage medium storage tank 210 for cold storage, the corresponding valve of the connecting pipe 300 of the main pipeline that is usually in operation is closed, and the valves in the other connecting pipes 300 of the main pipeline are opened, that is:

[0090] First, open the inlet and outlet valves corresponding to the series and parallel operation of the cold storage medium storage tanks 210 corresponding to the 5th and 4th rows, close the valves on the connecting pipes 300 corresponding to the 5th and 4th rows, close all the inlet and outlet valves of the cold storage medium storage tanks 210 in rows 1-3, and open the valves on the connecting pipes 300 corresponding to rows 1-3. Low-temperature air enters from the bottom of the cold storage medium storage tanks 210 in the 5th row, exchanges heat with the solid cold storage medium in the 5th and 4th rows in turn, and then enters the corresponding connecting pipe 300 of the 3rd row from the top outlet of the cold storage medium storage tank group in the 4th row, flows back to the inlet of the circulating fan 100 through the main pipeline, and continues to circulate.

[0091] During operation, when the real-time average temperature measurement of the outlet temperature measurement point above the fifth row of cold storage medium storage tanks 210 reaches -160°C, it indicates that the cold storage of the cold storage medium storage tanks 210 is completed, the medium storage inlet and outlet valves of the cold storage medium storage tanks 210 are closed, and the valve on the corresponding through valve is opened; at the same time, if the actual temperature measured at the outlet temperature measurement point above the fourth row of cold storage medium storage tanks 210 is lower than the initial average temperature, the inlet and outlet valves corresponding to the third row of cold storage medium storage tanks 210 are opened, and the valve on the connecting pipe 300 corresponding to the third row is closed. The low-temperature air enters from the bottom of the cold storage medium storage tanks 210 in operation in the fourth row through the connecting pipe 300 corresponding to the fifth row, exchanges heat with the solid cold storage medium in the fourth and third rows in turn, and then enters the connecting pipe 300 corresponding to the second row from the outlet of the third row of cold storage medium storage tanks, and flows back to the inlet of the circulating fan 100 through the main pipeline, and continues to circulate.

[0092] During operation, when the real-time average temperature measured at the outlet temperature measuring point above the 4th row of cold storage medium storage tanks 210 reaches -160°C, it indicates that the cold storage of the cold storage medium storage tanks 210 is completed, the medium storage inlet and outlet valves of the cold storage medium storage tanks 210 are closed, and the valve on the corresponding through valve is opened; at the same time, if the actual temperature measured at the outlet temperature measuring point above the 3rd row of cold storage medium storage tanks 210 is lower than the initial average temperature, the inlet and outlet valves corresponding to the 2nd row of cold storage medium storage tanks 210 are opened, and the valve on the connecting pipe 300 corresponding to the 2nd row is closed. The low-temperature air enters from the bottom of the cold storage medium storage tanks 210 in operation in the 3rd row through the connecting pipes 300 corresponding to the 5th and 4th rows, exchanges heat with the solid cold storage media in the 3rd and 2nd rows in turn, and then enters the connecting pipe 300 corresponding to the 1st row from the outlet of the 2nd row of cold storage medium storage tanks, flows back to the inlet of the circulating fan 100, and continues to circulate.

[0093] During operation, when the real-time average temperature measured at the outlet temperature measuring point above the third row of cold storage medium storage tanks 210 reaches -160°C, it indicates that the cold storage medium storage tank 210 has completed cold storage, and the inlet and outlet valves of the cold storage medium storage tank 210 are closed, and the valve on the corresponding through valve is opened; at the same time, if the actual temperature measured at the outlet temperature measuring point above the second row of cold storage medium storage tanks 210 is lower than the initial average temperature, the inlet and outlet valves corresponding to the first row of cold storage medium storage tanks 210 are opened, and the valve on the connecting pipe 300 corresponding to the first row is closed. The low-temperature air enters from the bottom of the second row of operating cold storage medium storage tanks 210 through the connecting pipes 300 corresponding to the 5th, 4th, and 3rd rows, exchanges heat with the solid cold storage medium in the second and first rows in turn, and then flows back from the outlet of the first row of cold storage medium storage tanks to the inlet of the circulating fan 100, and continues to circulate.

[0094] During operation, when the real-time average temperature measurement of the outlet temperature measurement point above the second row of cold storage medium storage tanks 210 reaches -160°C, it indicates that the cold storage of the cold storage medium storage tanks 210 is completed, and the medium storage inlet and outlet valves of the cold storage medium storage tanks 210 are closed, and the valve on the corresponding through valve is opened. Low-temperature air enters from the bottom of the cold storage medium storage tanks 210 in operation in the first row through the connecting pipes 300 corresponding to the 5th, 4th, 3rd, and 2nd rows, exchanges heat with the solid cold storage medium in the first row, and then flows back from the outlet of the first row of cold storage medium storage tanks to the inlet of the circulating fan 100.

[0095] When the inlet temperature of the circulating fan 100 is lower than the preset value C, it indicates that the cold storage operation is completed, the circulating fan 100 is automatically turned off, the medium storage inlet and outlet valves of the cold storage medium storage tank 210 are closed, and the valve on the corresponding through valve is opened. In some embodiments, when the cold storage step reaches the preset time length D, the fan will also be automatically turned off.

[0096] (2) Cooling unit

[0097] During the air liquefaction process, cold energy needs to be continuously supplemented to increase its liquefaction rate. One source of cold energy is the cold energy stored in the cold storage subsystem. With room temperature air as the cold medium, the circulating fan 100 continuously extracts cold energy from the cold storage medium storage tank 210 of the cold storage subsystem and inputs it into the cold box 500 to provide cold energy for air liquefaction. The cold energy release process inside the subsystem is that the clean air not higher than 25°C passes through the circulating fan 100, and the temperature rises to not higher than 27°C. After entering the cold storage medium storage tank 210 and exchanging heat with the solid cold storage medium in the packed bed, the temperature drops to -158°C, flows out from the outlet below the cold storage medium storage tank 210, and enters the cold box 500 for heat exchange, providing cold energy for the liquefaction of the air stream in the cold box 500, and then the temperature rises to room temperature (about 25°C).

[0098] Before the air flowing out of the cold box 500 and not higher than 25°C enters the cold storage medium tank 210 through the circulating fan 100, the valves corresponding to the two connecting pipes 300 in the main pipeline that are usually in operation are closed (only one connecting pipe 300 corresponding to the valve is closed at the end of the last cold storage medium tank 210 releasing cold), and the valves in the other connecting pipes 300 of the main pipeline are opened, that is:

[0099] Open the inlet and outlet valves of the cold storage medium storage tanks 210 corresponding to the first and second rows of series-parallel operation, and close the valves on the connecting pipes 300 corresponding to the first and second rows; all the inlet and outlet valves of the remaining cold storage medium storage tanks 210 are closed, and the valves on the connecting pipes 300 corresponding to the third to fifth rows are opened. Then the air enters from the top of the cold storage medium storage tanks 210 in the first row, exchanges heat with the solid cold storage medium in the first and second rows in turn, and then enters the corresponding connecting pipe 300 of the third row from the bottom of the second row of cold storage medium storage tanks. The cold air with a temperature not lower than -158°C flows back to the cold box 500 through the main pipeline to release the cold energy. After releasing the cold, the air rises to no higher than 27°C and then flows back to the circulating fan 100 for circulation.

[0100] During operation, when the real-time measured temperature average value of the inlet temperature measuring point below the first row of parallel cold storage medium tanks 210 reaches no less than 25°C, it indicates that the cold storage of the cold storage medium tanks 210 is completed, the inlet and outlet valves of the cold storage medium tanks 210 are closed, and the corresponding main pipeline valve is opened; at the same time, when the actual measured temperature of the outlet temperature measuring point below the second row of cold storage medium tanks 210 is higher than the initial average temperature, the inlet and outlet valves of the cold storage medium tanks 210 corresponding to the third row are opened, and the valve on the connecting pipe 300 corresponding to the third row is closed. Then the air enters from the top of the cold storage medium storage tank 210 in the second row through the connecting pipe 300 of the first row, exchanges heat with the solid cold storage medium in the second and third rows for cooling, and then enters the corresponding connecting pipe 300 of the fourth row from the bottom of the cold storage medium storage tank group in the third row. The cold air with a temperature not lower than -158°C flows back to the cold box 500 through the main pipeline to release the cold energy. After releasing the cold, the air rises to a temperature not higher than 27°C and then flows back to the circulating fan 100 for circulation.

[0101] During operation, when the real-time measured temperature average value of the inlet temperature measuring point below the second row of parallel cold storage medium tanks 210 reaches no less than 25°C, it indicates that the cold storage of the cold storage medium tanks 210 is completed, the inlet and outlet valves of the cold storage medium tanks 210 are closed, and the corresponding main pipeline valve is opened; at the same time, when the actual measured temperature of the outlet temperature measuring point below the third row of cold storage medium tanks 210 is higher than the initial average temperature, the inlet and outlet valves corresponding to the cold storage medium tanks 210 in the fourth row connected to the cold storage medium tanks 210 are opened, and the valve on the connecting pipe 300 corresponding to the fourth row is closed. Then the air passes through the connecting pipes 300 of the 1st and 2nd rows in turn, enters from the top of the cold storage medium storage tank 210 of the 3rd row, exchanges heat with the solid cold storage medium in the 3rd and 4th rows in turn for cooling, and then enters the corresponding connecting pipe 300 of the 5th row from the bottom end of the cold storage medium storage tank group in the 4th row. The cold air with a temperature not lower than -158°C flows back to the cold box 500 through the main pipeline to release the cold energy. After releasing the cold, the air rises to no higher than 27°C and then flows back to the circulating fan 100 for circulation.

[0102] During operation, when the real-time measured temperature average value of the inlet temperature measuring point below the third row of parallel cold storage medium tanks 210 reaches no less than 25°C, it indicates that the cold storage of the cold storage medium tanks 210 is completed, the inlet and outlet valves of the cold storage medium tanks 210 are closed, and the corresponding main pipeline valve is opened; at the same time, when the actual measured temperature of the outlet temperature measuring point below the fourth row of cold storage medium tanks 210 is higher than the initial average temperature, the inlet and outlet valves of the cold storage medium tanks 210 corresponding to the fifth row are opened, and the valve on the connecting pipe 300 corresponding to the fifth row is closed. Then the air passes through the connecting pipes 300 of the 1st, 2nd and 3rd rows in turn, enters from the top of the cold storage medium storage tank 210 of the 4th row, exchanges heat with the solid cold storage medium in the 4th and 5th rows in turn for cooling, and then flows out from the bottom of the cold storage medium storage tank group in the 5th row. The cold air with a temperature not lower than -158°C flows back to the cold box 500 to release the cold energy. After releasing the cold, the air rises to a temperature not higher than 27°C and then flows back to the circulating fan 100 for circulation.

[0103] During operation, when the real-time average temperature measurement of the inlet temperature measurement point below the 4th row of parallel cold storage medium storage tanks 210 reaches not less than 25°C, it indicates that the cold storage medium storage tank 210 has completed cold storage, the inlet and outlet valves of the cold storage medium storage tank 210 are closed, and the corresponding main pipeline valve is opened. Then the air enters from the top of the cold storage medium storage tank 210 in the 5th row through the connecting pipes 300 of the 1st, 2nd, 3rd, and 4th rows in turn, exchanges heat with the solid cold storage medium in the 4th and 5th rows in turn and cools down before flowing out from the bottom of the 5th row of cold storage medium storage tank group. The cold air of not less than -158°C flows back to the cold box 500 to release the cold energy. After the cold is released, the air rises to not more than 27°C (preset value E) and then flows back to the circulation fan 100 for circulation. In some embodiments, when the inlet temperature of the circulation fan 100 is higher than the preset value E, it indicates that the cold release operation is completed and the circulation fan 100 is automatically closed. In some embodiments, when the cooling step reaches a preset time F, the fan will automatically shut down.

[0104] The method for recovering, storing and utilizing cold energy in liquid air by utilizing the cold storage subsystem provided by the present invention can control and switch the number of series and parallel connections of the cold storage medium storage tanks 210 according to the calculation of the temperature gradient layer and the cold storage time, which can effectively reduce the pressure loss during the operation of the cold storage subsystem, while preserving the cold energy storage quality, and controlling the temperature loss to 1-2°C. The specific preset values ​​in the control method can be adaptively adjusted according to the overall process design requirements.

[0105] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0106] Embodiment 1:

[0107] by Figure 1For operation reference, the capacity of a single tank of the cold storage medium storage tank 210 is 6MWh, the operating temperature is -145℃~-7℃, the operating pressure is 1.9~1.8MPa, and the arrangement of the cold storage medium storage tank 210 is as follows Figure 2 During operation, when the inlet pressure of the circulating fan 100 is lower than 1.8 MPa, the constant pressure pump 610 is turned on to supplement the system pressure; the control method of the cold storage subsystem includes:

[0108] (1) Cold storage unit

[0109] Liquid air enters the evaporator 400 through the cryogenic pump 800 to evaporate and vaporize. The normal temperature air driven by the circulating fan 100 of the cold storage system enters the evaporator 400 to absorb cold energy, and then recovers it to the liquid-air cold storage medium tank 210 for storage. The system circulation medium uses clean air. After the evaporator 400 exchanges heat with the liquid air, the liquid air at -149°C exchanges heat with the clean air at -6°C. When the clean air flows out of the cold end of the evaporator 400, the temperature drops to -145°C and then prepares for cold energy storage; when the clean air outlet temperature is higher than -145°C, the fan flow rate is reduced; when the clean air outlet temperature is lower than -145°C, the fan flow rate is increased. The normal operation of the thermal pressure drop of the evaporator 400 is 20-25KPa. If the pressure drop increases to 30KPa, the system alarms and maintenance personnel are arranged for maintenance during the non-operating stage of the equipment.

[0110] Before the low-temperature air flowing out of the cold end of the evaporator 400 enters the cold storage medium storage tank 210 for cold storage, the 4# and 5# valves of the main pipeline are closed, and the other valves of the main pipeline are opened; the valves connected to the cold storage medium storage tanks 210 of the cold storage medium storage tank units 200 1-3 are all closed. The low-temperature air enters from the bottom of the two cold storage medium storage tanks 210 in the fifth row, exchanges heat with the solid cold storage medium therein to increase the temperature, and then enters the two cold storage medium storage tanks 210 in the fourth row to continue heat exchange, and then flows out from the top of the cold storage medium storage tank 210 to be collected in the main pipeline, and flows back to the inlet of the circulating fan 100 to continue the circulation operation. When the real-time average temperature value of the outlet temperature measuring points above the two cold storage medium storage tanks 210 in the 5th row reaches -144°C, it means that the cold storage of the cold storage medium storage tanks 210 in the 5th row is completed, and the inlet and outlet valves of the two cold storage medium storage tanks 210 in the 5th row are closed, and the 5# valve is opened; when the actual measured temperature of the outlet temperature measuring points above the cold storage medium storage tanks 210 in the 4th row is lower than the initial average temperature, the two cold storage medium storage tanks 210 in the 3rd row are opened, and the 3# valve of the main pipeline is closed; the subsequent air exchanges heat with the 4th row and the 3rd row, the 3rd row and the 2nd row, the 2nd row and the 1st row, and the 1st row in turn. When the fan inlet temperature is lower than -20°C, the liquid-air cold storage in the energy release and power generation stage is completed, and the fan is turned off.

[0111] (2) Cooling unit

[0112] During the air liquefaction process, cold energy needs to be continuously supplemented to increase its liquefaction rate. One source of cold energy is the cold energy stored in the cold storage subsystem. With room temperature air as the cold medium, the circulating fan 100 continuously extracts cold energy from the cold storage medium storage tank 210 of the cold storage subsystem and inputs it into the cold box 500 to provide cold energy for air liquefaction. The cold energy release process inside the subsystem is as follows: the clean air at -10°C rises to -7°C after passing through the circulating fan 100, enters the cold storage medium storage tank 210, and exchanges heat with the solid cold storage medium in the packed bed. The temperature drops to -142°C, flows out from the outlet below the cold storage medium storage tank 210, enters the cold box 500 for heat exchange, and then rises to -10°C and flows back to the inlet of the circulating fan 100.

[0113] Before the -7℃ air enters the cold storage medium tank 210, the 1# and 2# valves of the main pipeline are closed, and the other valves of the main pipeline are opened; the valves connected to the cold storage medium tanks 210 in the 3rd, 4th and 5th rows of the cold storage medium tank unit 200 are all closed. Then the air enters from the top of the two cold storage medium tanks 210 in the first row, exchanges heat with the low-temperature cold storage medium therein, and enters the two cold storage medium tanks 210 in the second row. After continuing the heat exchange, it flows out from the bottom of the cold storage medium tank 210 and is collected in the main pipeline. The -142℃ cold air enters the cold box 500 to release the cold energy, and the air rises to -10℃ and then flows back to the circulation fan 100 for circulation. When the real-time average temperature of the outlet temperature measuring point below the first row of cold storage medium storage tanks 210 reaches -9°C, it means that the first row of cold storage medium storage tanks 210 have completed the cold release, and the inlet and outlet valves of the two cold storage medium storage tanks 210 in the first row are closed, and the 1# valve is opened; when the measured temperature of the outlet temperature measuring point below the second row of cold storage medium storage tanks 210 is higher than the initial average temperature, the two cold storage medium storage tanks 210 in the third row are opened, and the 3# valve of the main pipeline is closed. The subsequent air exchanges heat with the second and third rows, the third and fourth rows, the fourth and fifth rows, and the fifth row in turn, and the duration of the cold release step reaches 10 hours, completing the cold release process of the energy storage stage.

[0114] Embodiment 2:

[0115] by Figure 1 For operation reference, the capacity of a single cold storage medium tank 210 is 20MWh, the operating temperature is -149℃~7.4℃, the operating pressure is 1.9~1.83MPa, and the cold storage medium tank 210 is arranged as follows Figure 2 As shown, during operation, when the inlet pressure of the circulating fan 100 is lower than 1.83 MPa, the constant pressure pump 610 is turned on to supplement the system pressure; the control method of the cold storage subsystem includes:

[0116] (1) Cold storage unit

[0117] Liquid air enters the evaporator 400 through the cryogenic pump 800 to evaporate and vaporize. The normal temperature air driven by the circulating fan 100 of the cold storage system enters the evaporator 400 to absorb cold energy, and then recovers it to the liquid-air cold storage medium tank 210 for storage. The system circulation medium uses clean air. After heat exchange with liquid air in the evaporator 400, the liquid air at -153°C exchanges heat with the clean air at 9°C. When the clean air flows out of the cold end of the evaporator 400, the temperature drops to -149°C and then prepares for cold energy storage; when the clean air outlet temperature is higher than -149°C, the fan flow rate is reduced; when the clean air outlet temperature is lower than -149°C, the fan flow rate is increased. The normal operation of the thermal pressure drop of the evaporator 400 is 25KPa. If the pressure drop increases to 30KPa, the system alarms and maintenance personnel are arranged for maintenance during the non-operating stage of the equipment.

[0118] Before the low-temperature air flowing out of the cold end of the evaporator 400 enters the cold storage medium storage tank 210 for cold storage, the 4# and 5# valves of the main pipeline are closed, and the other valves of the main pipeline are opened; the valves connected to the cold storage medium storage tanks 210 of the cold storage medium storage tank units 200 1-3 are all closed. The low-temperature air enters from the bottom of the two cold storage medium storage tanks 210 in the fifth row, exchanges heat with the solid cold storage medium therein to increase the temperature, and then enters the two cold storage medium storage tanks 210 in the fourth row to continue heat exchange, and then flows out from the top of the cold storage medium storage tank 210 to be collected in the main pipeline, and flows back to the inlet of the circulating fan 100 to continue the circulation operation. When the real-time average temperature measurement of the outlet temperature measuring point above the two cold storage medium storage tanks 210 in the 5th row reaches -148°C, it means that the cold storage of the cold storage medium storage tanks 210 in the 5th row is completed, and the inlet and outlet valves of the two cold storage medium storage tanks 210 in the 5th row are closed, and the 5# valve is opened; when the actual measured temperature of the outlet temperature measuring point above the cold storage medium storage tanks 210 in the 4th row is lower than the initial average temperature, the two cold storage medium storage tanks 210 in the 3rd row are opened, and the 3# valve of the main pipeline is closed; the subsequent air exchanges heat with the 4th row and the 3rd row, the 3rd row and the 2nd row, the 2nd row and the 1st row, and the 1st row in turn. When the fan inlet temperature is lower than -20°C, the fan is turned off to complete the liquid-air cold storage in the energy release and power generation stage.

[0119] (2) Cooling unit

[0120] During the air liquefaction process, cold energy needs to be continuously supplemented to increase its liquefaction rate. One source of cold energy is the cold energy stored in the cold storage subsystem. With room temperature air as the cold medium, the circulating fan 100 continuously extracts cold energy from the cold storage medium storage tank 210 of the cold storage subsystem and inputs it into the cold box 500 to provide cold energy for air liquefaction. The cold energy release process inside the subsystem is that the clean air at 5°C rises to 7.4°C after passing through the circulating fan 100, enters the cold storage medium storage tank 210, and exchanges heat with the solid cold storage medium in the packed bed. The temperature drops to -146°C and flows out from the outlet below the cold storage medium storage tank 210. It enters the cold box 500 for heat exchange, and then the temperature rises to 5°C and flows back to the inlet of the circulating fan 100.

[0121] Before the 7.4℃ air enters the cold storage medium tank 210, the 1# and 2# valves of the main pipeline are closed, and the other valves of the main pipeline are opened; the valves connected to the cold storage medium tanks 210 in the 3rd, 4th and 5th rows of the cold storage medium tank unit 200 are all closed. Then the air enters from the top of the two cold storage medium tanks 210 in the first row, exchanges heat with the low-temperature cold storage medium therein, and then enters the two cold storage medium tanks 210 in the second row. After further heat exchange, it flows out from the bottom of the cold storage medium tank 210 and is collected in the main pipeline. The -146℃ cold air enters the cold box 500 to release the cold energy, and the air rises to 5℃ and then flows back to the circulation fan 100 for circulation. When the real-time average temperature of the outlet temperature measuring point below the first row of cold storage medium storage tanks 210 reaches 6.5°C, it means that the first row of cold storage medium storage tanks 210 have completed the cold release, and the two outlet valves of the first row of cold storage medium storage tanks 210 are closed, and the 1# valve is opened; when the measured temperature of the outlet temperature measuring point below the second row of cold storage medium storage tanks 210 is higher than the initial average temperature, the two cold storage medium storage tanks 210 in the third row are opened, and the 3# valve of the main pipeline is closed. The subsequent air exchanges heat with the second and third rows, the third and fourth rows, the fourth and fifth rows, and the fifth row in turn, and the duration of the cold release step reaches 8 hours, completing the cold release process of the energy storage stage.

[0122] The pressure loss and temperature loss of a single cold storage medium tank 210 in Example 1 and Example 2 were measured, and the results are shown in Table 1.

[0123] Table 1

[0124]

[0125] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A cold storage subsystem, characterized in that: It includes a circulating fan, a cold storage medium tank unit, an evaporator for heat exchange between liquid air and high-temperature cold medium, and a cold box for heat exchange with low-temperature cold medium, wherein; The outlet of the circulation fan is connected to the cold medium inlet of the evaporator, the cold medium outlet of the evaporator is connected to the first inlet and outlet of the cold storage medium tank unit, and the second inlet and outlet of the cold storage medium tank unit is connected to the inlet of the circulation fan; The outlet of the cold box is connected to the inlet of the circulating fan, the outlet of the circulating fan is also connected to the second inlet and outlet of the cold storage medium tank unit, and the first inlet and outlet of the cold storage medium tank unit is connected to the inlet of the cold box; The liquid air inlet of the evaporator is connected to a liquid air storage tank, a pressure compensation pipe is provided between the liquid air storage tank and the liquid air inlet of the evaporator, and the pressure compensation pipe is connected to the second inlet and outlet of the cold storage medium storage tank unit.

2. The cold storage subsystem according to claim 1, characterized in that: The pressure compensation pipe is provided with a constant pressure pump.

3. The cold storage subsystem according to claim 1, characterized in that: The cold storage medium tank unit comprises n cold storage medium tank groups connected in series, each of the cold storage medium tank groups comprises two or more cold storage medium tanks, wherein n is an integer greater than or equal to 2; Each of the cold storage medium tank groups includes a first inlet and outlet of the cold storage medium tank group connected to the first inlet and outlet of each of the cold storage medium tanks in the group and a second inlet and outlet of the cold storage medium tank group connected to the second inlet and outlet of each of the cold storage medium tanks in the group, the first inlet and outlet of the nth cold storage medium tank group is the first inlet and outlet of the cold storage medium tank unit, and the second inlet and outlet of the first cold storage medium tank group is the second inlet and outlet of the cold storage medium tank unit; Each of the cold storage medium tank groups further includes a connecting pipe connected between the first inlet and outlet of the corresponding cold storage medium tank group and the second inlet and outlet of the corresponding cold storage medium tank group, and each of the connecting pipes is provided with a valve.

4. The cold storage subsystem according to claim 1, characterized in that: The cold storage medium storage tanks in the cold storage medium storage tank unit are arranged in a rectangular array.

5. The cold storage subsystem according to claim 1, characterized in that: The cold storage medium tank unit comprises a mother tank, which comprises an inner tank body and an outer tank body. The cold storage medium tanks in the cold storage medium tank unit are arranged in a circular array between the inner tank body and the outer tank body with the axis of the mother tank as the axis.

6. The cold storage subsystem according to claim 5, characterized in that: In the mother tank, thermal insulation filling materials are provided between two adjacent cold storage medium storage tanks; And / or, a filter is provided between the first inlet and outlet of the cold storage medium tank unit and the cold medium inlet of the cold box; And / or, a filter is provided between the second inlet and outlet of the cold storage medium tank unit and the inlet of the circulation fan.

7. A method for recovering, storing and utilizing cold energy in liquid air using the cold storage subsystem according to any one of claims 1 to 6, characterized in that: include: Cold storage: using a circulating fan to drive the cooling medium to first recover the cold energy generated by the evaporation of liquid air through the evaporator, and then store the cold energy in the cold storage medium tank through the cold storage medium; To release the cold, the circulating fan is used to drive the cold medium to first pass through the cold storage medium tank to absorb the cold energy stored therein, and then release the absorbed cold energy through the cold box.

8. The method for recovering, storing and utilizing cold energy in liquid air by utilizing a cold storage subsystem according to claim 7, characterized in that: Cold storage includes the following steps: The cooling medium that has passed through the evaporator first passes through the i-th cooling medium storage tank group and the i-1-th cooling medium storage tank group in sequence, and then passes through the circulating fan; When the i-th cold storage medium storage tank group has completed cold storage, the valve on the connecting pipe corresponding to the i-th cold storage medium storage tank group is opened, and the valve on the inlet and outlet of the cold storage medium storage tank corresponding to the i-th cold storage medium storage tank group is closed; when the temperature of the second inlet and outlet of the i-1-th cold storage medium storage tank group is lower than the temperature of the second inlet and outlet of the corresponding cold storage medium storage tank group when no cold medium passes through, the cold medium flowing out of the i-1-th cold storage medium storage tank group passes through the i-2-th cold storage medium storage tank group and then passes through the circulating fan; After the second cold storage medium storage tank group has completed cold storage, the valve on the connecting pipe corresponding to the second cold storage medium storage tank group is opened, and the valve on the inlet and outlet of the cold storage medium storage tank corresponding to the second cold storage medium storage tank group is closed; After the fan inlet temperature reaches a preset value C or the duration of the cold storage step reaches a preset duration D, the fan and the inlet and outlet valves of the cold storage medium storage tank corresponding to the first cold storage medium storage tank group are closed; Wherein, 3≤i≤n, and i is an integer.

9. The method for recovering, storing and utilizing cold energy in liquid air by utilizing a cold storage subsystem according to claim 7, characterized in that: In the cold release step, the cold medium that has passed through the circulating fan first passes through the jth cold storage medium storage tank group and the j+1th cold storage medium storage tank group in sequence and then passes through the cold box; After the cold storage medium storage tank group of the jth cold storage medium storage tank group has been released, the valve on the connecting pipe corresponding to the jth cold storage medium storage tank group is opened, and the valve on the cold storage medium storage tank inlet and outlet corresponding to the jth cold storage medium storage tank group is closed; when the temperature of the first inlet and outlet of the j+1th cold storage medium storage tank group is higher than the temperature of the first inlet and outlet of the corresponding cold storage medium storage tank group when no cold medium passes through, the cold medium flowing out of the j+1th cold storage medium storage tank group passes through the circulation fan after passing through the j+2th cold storage medium storage tank group; After the n-1th cold storage medium storage tank group has finished releasing cold, the valve on the connecting pipe corresponding to the n-1th cold storage medium storage tank group is opened, and the valve on the inlet and outlet of the cold storage medium storage tank corresponding to the n-1th cold storage medium storage tank group is closed; After the fan inlet temperature reaches a preset value E or the duration of the cooling step reaches a preset duration F, the fan and the inlet and outlet valves of the cold storage medium storage tank corresponding to the nth cold storage medium storage tank group are closed; Wherein, 1≤j≤n-2, and j is an integer.

10. The method for recovering, storing and utilizing cold energy in liquid air by utilizing a cold storage subsystem according to claim 8, characterized in that: When the temperature of the cooling medium leaving the cooling medium outlet of the evaporator is higher than a preset value A, the flow rate of the circulating fan is reduced; when the temperature of the cooling medium leaving the cooling medium outlet of the evaporator is lower than the preset value A, the flow rate of the circulating fan is increased; And / or, if the evaporator thermal pressure drop is greater than the preset value B, the system alarms.

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