Mixed working medium low-temperature high-pressure hydrogen storage system using cold-carrying circulation

Abstract

The mixed working medium low-temperature and high-pressure hydrogen storage system using the cold-carrying circulation comprises a mixed working medium main cold circulation, the cold-carrying circulation and a hydrogen path, the mixed working medium throttling refrigeration technology is adopted for being coupled with the cold-carrying circulation, and the cold energy generated by the mixed working medium main cold circulation is transmitted to the hydrogen path through the cold-carrying circulation; high-pressure hydrogen distributed cooling is well matched while high efficiency of main cooling circulation of a mixed working medium is maintained, and the constant-temperature cooling load conforming to a low-temperature and high-pressure storage tank is met; a complex multi-stream high-pressure heat exchanger with a large heat exchange load is simplified into a double-stream heat exchanger with a small heat exchange load, so that the manufacturing difficulty and the manufacturing cost of the high-pressure hydrogen cooling heat exchanger are greatly reduced; the whole system can realize low-temperature and high-pressure densification storage of hydrogen, and has the advantages of high hydrogen storage density, low hydrogen storage energy consumption and low system construction cost.

Description

Technical Field

[0001] The present application relates to the technical field of low-temperature refrigeration and hydrogen storage, and in particular to a mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle. Background Art

[0002] Hydrogen is green and carbon-free, and will be an important secondary energy carrier in the future. However, the storage and transportation difficulties caused by the low density and low boiling point of hydrogen have greatly restricted the development of hydrogen energy technology, and there is an urgent need to develop efficient and compact hydrogen storage technology. The low-temperature and high-pressure hydrogen storage technology that pressurizes hydrogen at room temperature and then distributes and cools it has a hydrogen storage density equivalent to that of liquid hydrogen, and has the advantages of low energy consumption, no need for normal-parahydrogen conversion, and convenient hydrogen use. It is a new type of hydrogen storage method with great development potential. Mixed working fluid refrigeration technology can effectively match the cooling load of hydrogen, and is a better choice for achieving low-energy hydrogen storage.

[0003] However, during the low-temperature and high-pressure hydrogen storage process, on the one hand, the sensible heat load of hydrogen needs to be distributed cooled, and on the other hand, the heat capacity of the hydrogen storage container and the compression heat during the filling process also need to be cooled. The temporal and spatial distribution of the cooling load is complex, and the existing mixed working fluid refrigeration system is difficult to directly meet the needs. In addition, there are problems such as the difficulty in manufacturing multi-stream high-pressure heat exchangers, which restricts the further development of low-temperature and high-pressure hydrogen storage technology. Summary of the invention

[0004] In view of this, it is necessary to provide a mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle that can efficiently match various cooling loads and reduce the difficulty of manufacturing high-pressure hydrogen heat exchangers to address the current technical defects such as the difficulty in manufacturing multi-stream high-pressure heat exchangers that restrict the further development of low-temperature and high-pressure hydrogen storage technology.

[0005] To solve the above problems, this application adopts the following technical solutions:

[0006] The present application provides a mixed working fluid low temperature and high pressure hydrogen storage system using a cold carrier cycle, comprising: a mixed working fluid main cold cycle, a cold carrier cycle and a hydrogen gas circuit, wherein:

[0007] The mixed working fluid main cooling cycle is used to cool the cooling medium and provide refrigeration capacity for high-pressure hydrogen cooling. The mixed working fluid main cooling cycle comprises a mixed working fluid compressor (101), a mixed working fluid aftercooler (102), a mixed working fluid regenerator (103) and a mixed working fluid throttling element (104);

[0008] The cold-carrying cycle is used to transfer the cold generated by the mixed working medium main cold cycle to the hydrogen path, and the cold-carrying cycle comprises a cold-carrying compressor (201), an aftercooler (202), a hydrogen cooling heat exchanger (203), a cold-carrying throttling element (204) and a tank cooler (205);

[0009] The hydrogen circuit includes a multi-stage hydrogen compressor (301), an aftercooler (302) and a low-temperature and high-pressure storage tank (304);

[0010] The mixed working fluid is pressurized by the mixed working fluid compressor (101) and enters the mixed working fluid aftercooler (102) and is cooled to room temperature in the mixed working fluid aftercooler (102) to form a high-pressure mixed working fluid. The high-pressure mixed working fluid then enters the mixed working fluid regenerator (103) and is cooled by the low-pressure mixed working fluid and then throttled and cooled in the mixed working fluid throttling element (104) to form a low-pressure mixed working fluid. The low-pressure mixed working fluid then returns to the mixed working fluid regenerator (103) and provides cooling. The low-pressure mixed working fluid is reheated in the mixed working fluid regenerator (103) and returns to the mixed working fluid compressor (101) to complete the cycle.

[0011] The cooling medium is pressurized by the cooling compressor (201) and enters the aftercooler (202). The low-pressure mixed medium is cooled to 77K-150K in the mixed medium regenerator (103) to form a low-temperature cooling medium. The low-temperature cooling medium is then cooled and depressurized in the cooling throttling element (204) to form a low-temperature and low-pressure cooling medium. The low-temperature and low-pressure cooling medium enters the storage tank cooler (205) and the hydrogen cooling heat exchanger (203) in sequence to provide cooling capacity, and returns to the cooling compressor (201) after reheating to complete the cooling cycle.

[0012] After being pressurized by the multi-stage hydrogen compressor (301), the low-pressure raw hydrogen enters the aftercooler (302) to be cooled to form high-pressure hydrogen. The high-pressure hydrogen enters the hydrogen cooling heat exchanger (203) to be cooled to the hydrogen storage temperature to form low-temperature high-pressure hydrogen. The low-temperature high-pressure hydrogen then enters the low-temperature high-pressure storage tank (304) for storage. The heat capacity of the low-temperature high-pressure storage tank (304) itself and the compression heat generated by the low-temperature high-pressure hydrogen being filled into the low-temperature high-pressure storage tank (304) are both cooled by the tank cooler (205) to maintain the target hydrogen storage temperature.

[0013] In some embodiments, the mixed working medium main cooling cycle further includes a precooling unit (105) and a precooling heat exchanger (106).

[0014] The mixed working fluid is pressurized by the mixed working fluid compressor (101) and enters the mixed working fluid aftercooler (102) and is cooled to room temperature in the mixed working fluid aftercooler (102) to form a high-pressure mixed working fluid. The high-pressure mixed working fluid enters the precooling heat exchanger (106) for precooling and then enters the mixed working fluid regenerator (103);

[0015] The cooling medium is pressurized by the cooling compressor (201) and enters the aftercooler (202), and is precooled by the precooling heat exchanger (106) before entering the mixed medium reheater (103);

[0016] The precooling unit (105) is used to provide precooling cooling capacity for the precooling heat exchanger (106). The precooling unit (105) can adopt, but is not limited to, a combination of one or more of a steam compression refrigeration cycle, a mixed working fluid throttling refrigeration cycle, an absorption refrigeration cycle, an adsorption refrigeration cycle and a commercial chiller.

[0017] In some of the embodiments, the hydrogen circuit further includes a high-pressure hydrogen control valve group (303), and the hydrogen is cooled to the hydrogen storage temperature in the hydrogen cooling heat exchanger (203) to form low-temperature high-pressure hydrogen, which is controlled by the high-pressure hydrogen control valve group (303) and then enters the low-temperature high-pressure storage tank (304) for storage.

[0018] In some of the embodiments, the high-pressure hydrogen control valve group (303) includes a plurality of parallel high-pressure hydrogen control valves, and the low-temperature and high-pressure storage tank (304) is a low-temperature and high-pressure storage tank corresponding to the plurality of parallel high-pressure hydrogen control valves, and the plurality of parallel high-pressure hydrogen control valves can simultaneously fill the low-temperature and high-pressure storage tank group with low-temperature and high-pressure hydrogen; any low-temperature and high-pressure storage tank is correspondingly provided with the tank cooler (205), and any tank cooler (205) can cool the corresponding low-temperature and high-pressure storage tank.

[0019] In some of the embodiments, the cold-carrying cycle further comprises a tank cooler stop valve (206) and a tank cooler bypass valve (207). Under the regulation of the tank cooler stop valve (206) and the tank cooler bypass valve (207), the flow rate of the low-temperature and low-pressure cold-carrying medium formed by the temperature reduction and pressure reduction in the cold-carrying throttling element (204) entering the tank cooler (205) can be controlled.

[0020] In some of the embodiments, the refrigeration cycle also includes a refrigeration working fluid group (208), and the refrigeration working fluid group (208) can be in the form of but not limited to PSA or membrane separation or steel cylinder or small air separation distillation tower to supplement the refrigeration working fluid lost during the operation of the refrigeration cycle.

[0021] In some of the embodiments, the refrigeration cycle also includes a refrigeration medium storage tank (206) and a refrigeration medium control valve group (207); the refrigeration medium supplemented by the refrigeration medium group (208) is stored in the refrigeration medium storage tank (206), and then replenished into the refrigeration cycle through the refrigeration medium control valve group (207); the refrigeration medium participating in the cycle can also be returned to the refrigeration medium storage tank (206) through the refrigeration medium control valve group (207) to achieve the regulation of the refrigeration cycle working medium flow and operating pressure.

[0022] In some of the embodiments, the cooling medium used in the cooling cycle includes but is not limited to at least one of nitrogen, air, argon, neon, helium, hydrogen, methane, ethane, propane, R14 or natural gas.

[0023] This application adopts the above technical solution, and its beneficial effects are as follows:

[0024] The mixed working fluid low-temperature and high-pressure hydrogen storage system using a cooling-carrying cycle provided in the present application comprises: a mixed working fluid main cooling cycle, a cooling-carrying cycle and a hydrogen path, and adopts a mixed working fluid throttling refrigeration technology to couple the cooling-carrying cycle, and the cooling capacity generated by the mixed working fluid main cooling cycle is transferred to the hydrogen path through the cooling-carrying cycle, so that the mixed working fluid main cooling cycle is maintained at a relatively high efficiency while well matching the distributed cooling of high-pressure hydrogen to meet the constant temperature cooling load of the low-temperature and high-pressure storage tank; and the complex multi-stream high-pressure heat exchanger with a large heat exchange load is simplified into a double-stream heat exchanger with a smaller heat exchange load, which greatly reduces the manufacturing difficulty and manufacturing cost of the high-pressure hydrogen cooling heat exchanger; the entire system can realize low-temperature and high-pressure dense storage of hydrogen, and has the advantages of high hydrogen storage density, low hydrogen storage energy consumption, and low system construction cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 A schematic diagram of a mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in Example 1 of the present invention.

[0027] Figure 2 A schematic diagram of a mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in Example 2 of the present invention.

[0028] Figure 3 A schematic diagram of a mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in Example 3 of the present invention.

[0029] Figure 4 A schematic diagram of a mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in Example 4 of the present invention.

[0030] Figure 5 A schematic diagram of a mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in Example 5 of the present invention.

[0031] Figure 6 A schematic diagram of a mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in Example 6 of the present invention. DETAILED DESCRIPTION

[0032] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0033] In the description of the present application, it should be understood that the terms "upper", "lower", "horizontal", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0036] Example 1

[0037] See also Figure 1 , is a schematic diagram of the structure of a mixed working fluid low temperature and high pressure hydrogen storage system using a carrier cooling cycle provided in an embodiment of the present application, including: a mixed working fluid main cooling cycle, a carrier cooling cycle and a hydrogen path. The specific structure of each component is described in detail below.

[0038] The mixed working fluid main cooling cycle is used to cool the cooling medium and provide refrigeration capacity for high-pressure hydrogen cooling. The mixed working fluid main cooling cycle comprises a mixed working fluid compressor (101), a mixed working fluid aftercooler (102), a mixed working fluid regenerator (103) and a mixed working fluid throttling element (104).

[0039] The cold-carrying cycle is used to transfer the cold energy generated by the mixed working medium main cold cycle to the hydrogen path, and the cold-carrying cycle includes a cold-carrying compressor (201), an aftercooler (202), a hydrogen cooling heat exchanger (203), a cold-carrying throttling element (204) and a tank cooler (205).

[0040] The hydrogen circuit comprises a multi-stage hydrogen compressor (301), an aftercooler (302) and a low-temperature and high-pressure storage tank (304).

[0041] The mixed working fluid low temperature and high pressure hydrogen storage system using a cold cycle provided in this embodiment 1 works as follows:

[0042] The mixed working fluid is pressurized by the mixed working fluid compressor (101) and enters the mixed working fluid aftercooler (102) and is cooled to room temperature in the mixed working fluid aftercooler (102) to form a high-pressure mixed working fluid. The high-pressure mixed working fluid then enters the mixed working fluid regenerator (103) and is cooled by the low-pressure mixed working fluid and then throttled and cooled in the mixed working fluid throttling element (104) to form a low-pressure mixed working fluid. The low-pressure mixed working fluid then returns to the mixed working fluid regenerator (103) and provides cooling. The low-pressure mixed working fluid is reheated in the mixed working fluid regenerator (103) and returns to the mixed working fluid compressor (101) to complete the cycle.

[0043] The cooling medium is pressurized by the cooling compressor (201) and enters the aftercooler (202) and is cooled to 77K-150K by the low-pressure mixed medium in the mixed medium regenerator (103) to form a low-temperature cooling medium. The low-temperature cooling medium is then cooled and depressurized in the cooling throttling element (204) to form a low-temperature and low-pressure cooling medium. The low-temperature and low-pressure cooling medium sequentially enters the storage tank cooler (205) and the hydrogen cooling heat exchanger (203) to provide cooling capacity, and returns to the cooling compressor (201) after being reheated to complete the cooling cycle.

[0044] After being pressurized by the multi-stage hydrogen compressor (301), the low-pressure raw hydrogen enters the aftercooler (302) to be cooled to form high-pressure hydrogen. The high-pressure hydrogen enters the hydrogen cooling heat exchanger (203) to be cooled to the hydrogen storage temperature to form low-temperature high-pressure hydrogen. The low-temperature high-pressure hydrogen then enters the low-temperature high-pressure storage tank (304) for storage. The heat capacity of the low-temperature high-pressure storage tank (304) itself and the compression heat generated by the low-temperature high-pressure hydrogen being filled into the low-temperature high-pressure storage tank (304) are both cooled by the tank cooler (205) to maintain the target hydrogen storage temperature.

[0045] In this embodiment, the cooling medium used in the cooling cycle includes but is not limited to at least one of nitrogen, air, argon, neon, helium, hydrogen, methane, ethane, propane, R14 or natural gas.

[0046] The mixed working fluid low-temperature and high-pressure hydrogen storage process using a cooling cycle provided in the above-mentioned embodiment 1 of the present invention adopts a mixed working fluid throttling refrigeration technology to couple the cooling cycle, and the cooling capacity generated by the mixed working fluid main cooling cycle is transferred to the hydrogen path through the cooling cycle, so that the mixed working fluid main cooling cycle is maintained at a relatively high efficiency while well matching the distributed cooling of high-pressure hydrogen to meet the constant temperature cooling load of the low-temperature and high-pressure storage tank; and the complex multi-stream high-pressure heat exchanger with a large heat exchange load is simplified into a double-stream heat exchanger with a smaller heat exchange load, which greatly reduces the manufacturing difficulty and manufacturing cost of the high-pressure hydrogen cooling heat exchanger; the entire system can realize low-temperature and high-pressure dense storage of hydrogen, and has the advantages of high hydrogen storage density, low hydrogen storage energy consumption, and low system construction cost.

[0047] Example 2

[0048] See also Figure 2 , which is a mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in Example 2 of the present application. For the convenience of explanation, only the relevant drawings are described below.

[0049] The difference from Example 1 is that the mixed working medium main cooling cycle also includes a precooling unit (105) and a precooling heat exchanger (106).

[0050] The mixed working fluid is pressurized by the mixed working fluid compressor (101) and enters the mixed working fluid aftercooler (102) and is cooled to room temperature in the mixed working fluid aftercooler (102) to form a high-pressure mixed working fluid. The high-pressure mixed working fluid enters the precooling heat exchanger (106) for precooling and then enters the mixed working fluid regenerator (103).

[0051] The cooling medium is pressurized by the cooling compressor (201) and then enters the aftercooler (202). It is precooled by the precooling heat exchanger (106) and then enters the mixed medium reheater (103).

[0052] The precooling unit (105) is used to provide precooling cooling capacity for the precooling heat exchanger (106). The precooling unit (105) can adopt but is not limited to a combination of one or more of a steam compression refrigeration cycle, a mixed working fluid throttling refrigeration cycle, an absorption refrigeration cycle, an adsorption refrigeration cycle and a commercial chiller. Other working modes can refer to Example 1 and will not be repeated here.

[0053] The mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in the above-mentioned embodiment 2 of the present invention reduces the types of components of the mixed working fluid main cold cycle by adopting a pre-cooling unit, thereby improving the system's ability to adapt to higher ambient temperatures and reducing the total energy consumption of high-pressure hydrogen cooling.

[0054] Example 3

[0055] See also Figure 3 , which is a mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in Example 3 of the present application. For the convenience of explanation, only the relevant drawings are described below.

[0056] The difference from Example 1 is that the hydrogen circuit also includes a high-pressure hydrogen control valve group (303), and the low-temperature high-pressure hydrogen is cooled to the hydrogen storage temperature in the hydrogen cooling heat exchanger (203) and enters the low-temperature high-pressure storage tank (304) for storage after being controlled by the high-pressure hydrogen control valve group (303).

[0057] Furthermore, the high-pressure hydrogen control valve group (303) comprises a plurality of high-pressure hydrogen control valves ( Figure 3 303a, 303b and 303c), the low temperature and high pressure storage tank (304) is a low temperature and high pressure storage tank ( Figure 3 304a, 304b and 304c), the plurality of parallel high-pressure hydrogen control valves can realize the simultaneous filling of the low-temperature and high-pressure hydrogen into the low-temperature and high-pressure storage tank group; any low-temperature and high-pressure storage tank is correspondingly provided with the storage tank cooler (205), and any storage tank cooler (205) can cool the corresponding low-temperature and high-pressure storage tank, for example, the storage tank cooler (205a), the storage tank cooler (205b), and the storage tank cooler (205c) can cool the low-temperature and high-pressure storage tank (304a), the low-temperature and high-pressure storage tank (304b) and the low-temperature and high-pressure storage tank (304c), respectively.

[0058] Other working methods can refer to Example 1 and Example 2, which will not be described in detail here.

[0059] The mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in the above-mentioned embodiment 3 of the present invention can simultaneously fill and cool multiple sets of storage tanks to meet the needs of large-scale hydrogen storage.

[0060] Example 4

[0061] See also Figure 4 , which is a mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in Example 4 of the present application. For the convenience of explanation, only the relevant drawings are described below.

[0062] The difference from Example 1 is that the cold-carrying cycle also includes a tank cooler stop valve (206) and a tank cooler bypass valve (207). Under the regulation of the tank cooler stop valve (206) and the tank cooler bypass valve (207), the flow rate of the low-temperature and low-pressure cold-carrying medium formed by the temperature reduction and pressure reduction in the cold-carrying throttling element (204) entering the tank cooler (205) can be controlled.

[0063] Specifically, closing the tank cooler bypass valve (207) and opening the tank cooler stop valve (206) can allow all the cooling medium to pass through the tank cooler (205) to provide cooling capacity, thereby meeting the larger tank cooling load requirement; adjusting the opening of the tank cooler stop valve (206) and the tank cooler bypass valve (207) can control the flow of the cooling medium flowing through the tank cooler (205), thereby achieving the adjustment of the cooling capacity distribution required for high-pressure hydrogen cooling and tank cooling.

[0064] Other working modes can refer to embodiments 1 to 3, which will not be described in detail here.

[0065] The mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in the above-mentioned embodiment 4 of the present invention adjusts the flow rate of the cold-carrying working fluid entering the tank cooler by setting a control valve group to achieve the adjustment of the cold capacity distribution.

[0066] Example 5

[0067] See also Figure 5 , which is a mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in Example 5 of the present application. For the convenience of explanation, only the relevant drawings are described below.

[0068] The difference from Example 1 is that the refrigeration cycle also includes a refrigeration working fluid group (208), and the refrigeration working fluid group (208) can be in the form of but not limited to PSA or membrane separation or steel cylinder or small air separation distillation tower to supplement the refrigeration working fluid lost during the operation of the refrigeration cycle.

[0069] Other working modes can refer to embodiments 1 to 4, which will not be described in detail here.

[0070] The mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in the above-mentioned embodiment 5 of the present invention utilizes a nitrogen generator to supplement the lost nitrogen to ensure stable operation of the system.

[0071] Example 6

[0072] See also Figure 6 , which is a mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold-carrying cycle provided in Example 6 of the present application. For the convenience of explanation, only the relevant drawings are described below.

[0073] The difference from Example 5 is that the refrigeration cycle also includes a refrigeration working fluid storage tank (206) and a refrigeration working fluid control valve group (207); the refrigeration working fluid supplemented by the refrigeration working fluid group (208) is stored in the refrigeration working fluid storage tank (206), and then replenished into the refrigeration cycle through the refrigeration working fluid control valve group (207); the refrigeration working fluid participating in the cycle can also be returned to the refrigeration working fluid storage tank (206) through the refrigeration working fluid control valve group (207) to achieve the regulation of the refrigeration cycle working fluid flow and operating pressure.

[0074] Other working modes can refer to embodiments 1 to 5, which will not be described in detail here.

[0075] The mixed working fluid low temperature and high pressure hydrogen storage system using a cold-carrying cycle provided in the above-mentioned embodiment 6 of the present invention utilizes a cold-carrying working fluid storage tank and a control valve group to realize the adjustment of the cycle operation condition, match the variable load, and improve the system efficiency. It can be understood that the technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] The above are only preferred embodiments of the present application, and only specifically describe the technical principles of the present application. These descriptions are only for explaining the principles of the present application and cannot be interpreted in any way as limiting the scope of protection of the present application. Based on the explanation here, any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application, and other specific implementation methods of the present application that can be associated with by technicians in this field without creative work, should be included in the scope of protection of the present application.

Claims

1. A mixed working fluid low temperature and high pressure hydrogen storage system using a cold cycle, It is characterized in that include: Mixed working medium main cooling cycle, secondary cooling cycle and hydrogen circuit, including: The mixed working fluid main cooling cycle is used to cool the cooling medium and provide refrigeration capacity for high-pressure hydrogen cooling. The mixed working fluid main cooling cycle comprises a mixed working fluid compressor (101), a mixed working fluid aftercooler (102), a mixed working fluid regenerator (103) and a mixed working fluid throttling element (104); The cold-carrying cycle is used to transfer the cold generated by the mixed working medium main cold cycle to the hydrogen path, and the cold-carrying cycle comprises a cold-carrying compressor (201), an aftercooler (202), a hydrogen cooling heat exchanger (203), a cold-carrying throttling element (204) and a tank cooler (205); The hydrogen circuit includes a multi-stage hydrogen compressor (301), an aftercooler (302) and a low-temperature and high-pressure storage tank (304); The mixed working fluid is pressurized by the mixed working fluid compressor (101) and enters the mixed working fluid aftercooler (102) and is cooled to room temperature in the mixed working fluid aftercooler (102) to form a high-pressure mixed working fluid. The high-pressure mixed working fluid then enters the mixed working fluid regenerator (103) and is cooled by the low-pressure mixed working fluid and then throttled and cooled in the mixed working fluid throttling element (104) to form a low-pressure mixed working fluid. The low-pressure mixed working fluid then returns to the mixed working fluid regenerator (103) and provides cooling. The low-pressure mixed working fluid is reheated in the mixed working fluid regenerator (103) and returns to the mixed working fluid compressor (101) to complete the cycle. The cooling medium is pressurized by the cooling compressor (201) and enters the aftercooler (202). The low-pressure mixed medium is cooled to 77K-150K in the mixed medium regenerator (103) to form a low-temperature cooling medium. The low-temperature cooling medium is then cooled and depressurized in the cooling throttling element (204) to form a low-temperature and low-pressure cooling medium. The low-temperature and low-pressure cooling medium enters the storage tank cooler (205) and the hydrogen cooling heat exchanger (203) in sequence to provide cooling capacity, and returns to the cooling compressor (201) after reheating to complete the cooling cycle. After being pressurized by the multi-stage hydrogen compressor (301), the low-pressure raw hydrogen enters the aftercooler (302) to be cooled to form high-pressure hydrogen. The high-pressure hydrogen enters the hydrogen cooling heat exchanger (203) to be cooled to the hydrogen storage temperature to form low-temperature high-pressure hydrogen. The low-temperature high-pressure hydrogen then enters the low-temperature high-pressure storage tank (304) for storage. The heat capacity of the low-temperature high-pressure storage tank (304) itself and the compression heat generated by the low-temperature high-pressure hydrogen being filled into the low-temperature high-pressure storage tank (304) are both cooled by the tank cooler (205) to maintain the target hydrogen storage temperature.

2. The mixed working fluid low temperature and high pressure hydrogen storage system using a cold cycle as claimed in claim 1, It is characterized in that The mixed working medium main cooling cycle also includes a precooling unit (105) and a precooling heat exchanger (106). The mixed working fluid is pressurized by the mixed working fluid compressor (101) and enters the mixed working fluid aftercooler (102) and is cooled to room temperature in the mixed working fluid aftercooler (102) to form a high-pressure mixed working fluid. The high-pressure mixed working fluid enters the precooling heat exchanger (106) for precooling and then enters the mixed working fluid regenerator (103); The cooling medium is pressurized by the cooling compressor (201) and enters the aftercooler (202), and is precooled by the precooling heat exchanger (106) before entering the mixed medium reheater (103); The precooling unit (105) is used to provide precooling cooling capacity for the precooling heat exchanger (106). The precooling unit (105) can adopt, but is not limited to, a combination of one or more of a steam compression refrigeration cycle, a mixed working fluid throttling refrigeration cycle, an absorption refrigeration cycle, an adsorption refrigeration cycle and a commercial chiller.

3. The mixed working fluid low temperature and high pressure hydrogen storage system using a cold cycle as claimed in claim 1, It is characterized in that The hydrogen circuit also includes a high-pressure hydrogen control valve group (303). The hydrogen is cooled to the hydrogen storage temperature in the hydrogen cooling heat exchanger (203) to form low-temperature high-pressure hydrogen, which is controlled by the high-pressure hydrogen control valve group (303) and then enters the low-temperature high-pressure storage tank (304) for storage.

4. The mixed working fluid low temperature and high pressure hydrogen storage system using a cold cycle as claimed in claim 3, It is characterized in that The high-pressure hydrogen control valve group (303) comprises a plurality of high-pressure hydrogen control valves connected in parallel, and the low-temperature and high-pressure storage tank (304) is a low-temperature and high-pressure storage tank arranged corresponding to the plurality of high-pressure hydrogen control valves connected in parallel, and the plurality of high-pressure hydrogen control valves connected in parallel can simultaneously fill the low-temperature and high-pressure storage tank group with low-temperature and high-pressure hydrogen; any low-temperature and high-pressure storage tank is correspondingly provided with the storage tank cooler (205), and any storage tank cooler (205) can cool the corresponding low-temperature and high-pressure storage tank.

5. The mixed working fluid low temperature and high pressure hydrogen storage system using a cold cycle as claimed in claim 1, It is characterized in that The cooling cycle also includes a tank cooler stop valve (206) and a tank cooler bypass valve (207). Under the regulation of the tank cooler stop valve (206) and the tank cooler bypass valve (207), the flow rate of the low-temperature and low-pressure cooling medium formed by the temperature reduction and pressure reduction in the cooling throttling element (204) entering the tank cooler (205) can be controlled.

6. The mixed working fluid low temperature and high pressure hydrogen storage system using a cold cycle as claimed in claim 1, It is characterized in that The refrigeration cycle also includes a refrigeration medium group (208), and the refrigeration medium group (208) can be in the form of but not limited to PSA or membrane separation or steel cylinder or small air separation distillation tower to supplement the refrigeration medium lost during the operation of the refrigeration cycle.

7. The mixed working fluid low temperature and high pressure hydrogen storage system using a cold cycle as claimed in claim 6, It is characterized in that The refrigeration cycle also includes a refrigeration medium storage tank (206) and a refrigeration medium control valve group (207); the refrigeration medium supplemented by the refrigeration medium group (208) is stored in the refrigeration medium storage tank (206), and then replenished into the refrigeration cycle through the refrigeration medium control valve group (207); the refrigeration medium participating in the circulation can also be returned to the refrigeration medium storage tank (206) through the refrigeration medium control valve group (207) to achieve regulation of the refrigeration cycle working medium flow and operating pressure.

8. The mixed working fluid low temperature and high pressure hydrogen storage system using a cold cycle as claimed in claim 1, It is characterized in that The cooling medium used in the cooling cycle includes but is not limited to at least one of nitrogen, air, argon, neon, helium, hydrogen, methane, ethane, propane, R14 or natural gas.

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