A mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold cycle

Abstract

The mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold carrier cycle provided in the present application includes: a mixed working fluid main cold cycle, a cold carrier cycle and a hydrogen circuit. The mixed working fluid throttling refrigeration technology is used to couple the cold carrier cycle, and the cold generated by the mixed working fluid main cold cycle is transferred to the hydrogen circuit through the cold carrier cycle, so that the mixed working fluid main cold cycle maintains a high efficiency while well matching the high-pressure hydrogen distributed cooling to meet the constant temperature cooling load of the low-temperature and high-pressure storage tank; and the complex large heat exchange load multi-flow high-pressure heat exchanger is simplified into a small heat exchange load double-flow heat exchanger, greatly reducing 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.

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 hydrogen's low density and low boiling point have greatly restricted the development of hydrogen energy technology, and there is an urgent need to develop efficient and compacted hydrogen storage technology. Low-temperature and high-pressure hydrogen storage technology, which pressurizes hydrogen at room temperature and then distributes it for cooling, has a hydrogen storage density comparable to that of liquid hydrogen. It also has the advantages of low energy consumption, no need for normal-parahydrogen conversion, and convenient hydrogen use. It is a new 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 distributedly 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, in order to address the technical defects such as the difficulty in manufacturing current multi-stream high-pressure heat exchangers, which 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 circuit, wherein:

[0007] The mixed working medium main cooling cycle is used to cool the cooling medium and provide refrigeration capacity for high-pressure hydrogen cooling. The mixed working medium main cooling cycle includes a mixed working medium compressor, a mixed working medium aftercooler, a mixed working medium regenerator and a mixed working medium throttling element.

[0008] The secondary cooling cycle is used to transfer the cold energy generated by the mixed working medium main cooling cycle to the hydrogen circuit, and the secondary cooling cycle includes a secondary cooling compressor, a first aftercooler, a hydrogen cooling heat exchanger, a secondary cooling throttling element and a tank cooler;

[0009] The hydrogen circuit includes a multi-stage hydrogen compressor, a second aftercooler and a low-temperature high-pressure storage tank;

[0010] The mixed working medium is pressurized by the mixed working medium compressor and enters the mixed working medium aftercooler and is cooled to room temperature in the mixed working medium aftercooler to form a high-pressure mixed working medium. The high-pressure mixed working medium then enters the mixed working medium regenerator and is cooled by the low-pressure mixed working medium. It is then throttled and cooled in the mixed working medium throttling element to form a low-pressure mixed working medium. The low-pressure mixed working medium then returns to the mixed working medium regenerator to provide cooling capacity. After the low-pressure mixed working medium is reheated in the mixed working medium regenerator, it returns to the mixed working medium compressor to complete the cycle.

[0011] The cold medium enters the first aftercooler after being pressurized by the cold medium compressor and is cooled to 77 K to 150 K by the low-pressure mixed medium in the mixed medium regenerator to form a low-temperature cold medium. The low-temperature cold medium is then cooled and depressurized in the cold medium throttling element to form a low-temperature, low-pressure cold medium. The low-temperature, low-pressure cold medium sequentially enters the tank cooler and the hydrogen cooling heat exchanger to provide cooling capacity, and after being reheated, returns to the cold medium compressor to complete the cold cycle.

[0012] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor and then enters the second aftercooler to be cooled to form high-pressure hydrogen. The high-pressure hydrogen enters the hydrogen cooling heat exchanger and is cooled to the hydrogen storage temperature to form low-temperature high-pressure hydrogen. The low-temperature high-pressure hydrogen then enters the low-temperature and high-pressure storage tank for storage. The heat capacity of the low-temperature and high-pressure storage tank itself and the compression heat generated by the low-temperature and high-pressure hydrogen being charged into the low-temperature and high-pressure storage tank are both cooled by the tank cooler to maintain the target hydrogen storage temperature.

[0013] In some embodiments, the mixed working medium main cooling cycle further includes a pre-cooling unit and a pre-cooling heat exchanger.

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

[0015] The cooling medium is pressurized by the cooling compressor, enters the first aftercooler, is precooled by the precooling heat exchanger, and then enters the mixed medium reheater;

[0016] The pre-cooling unit is used to provide pre-cooling cooling capacity for the pre-cooling heat exchanger. The pre-cooling unit 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 embodiments, the hydrogen circuit also includes a high-pressure hydrogen control valve group. The hydrogen is cooled to the hydrogen storage temperature in the hydrogen cooling heat exchanger to form low-temperature high-pressure hydrogen, which is controlled by the high-pressure hydrogen control valve group and then enters the low-temperature high-pressure storage tank for storage.

[0018] In some embodiments, the high-pressure hydrogen control valve group includes multiple parallel high-pressure hydrogen control valves, and the low-temperature and high-pressure storage tanks are low-temperature and high-pressure storage tanks arranged corresponding to the multiple parallel high-pressure hydrogen control valves. The multiple 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, and any tank cooler can cool the corresponding low-temperature and high-pressure storage tank.

[0019] In some embodiments, the cold-carrying cycle also includes a tank cooler shut-off valve and a tank cooler bypass valve. Under the regulation of the tank cooler shut-off valve and the tank cooler bypass valve, the flow rate of the low-temperature and low-pressure cold-carrying medium formed by cooling and reducing the pressure in the cold-carrying throttling element entering the tank cooler can be controlled.

[0020] In some embodiments, the refrigeration cycle also includes a refrigeration working fluid group, which 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 embodiments, the cold-carrying cycle also includes a cold-carrying working fluid storage tank and a cold-carrying working fluid control valve group. The cold-carrying working fluid replenished by the cold-carrying working fluid group is stored in the cold-carrying working fluid storage tank and then replenished into the cold-carrying cycle through the cold-carrying working fluid control valve group; the cold-carrying working fluid participating in the cycle can also be returned to the cold-carrying working fluid storage tank through the cold-carrying working fluid control valve group to achieve regulation of the cold-carrying cycle working fluid flow and operating pressure.

[0022] In some 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 cold carrier cycle provided in the present application includes: a mixed working fluid main cold cycle, a cold carrier cycle and a hydrogen circuit. The mixed working fluid throttling refrigeration technology is used to couple the cold carrier cycle, and the cold generated by the mixed working fluid main cold cycle is transferred to the hydrogen circuit through the cold carrier cycle, so that the mixed working fluid main cold cycle maintains a high efficiency while well matching the high-pressure hydrogen distributed cooling to meet the constant temperature cooling load of the low-temperature and high-pressure storage tank; and the complex large heat exchange load multi-flow high-pressure heat exchanger is simplified into a small heat exchange load double-flow heat exchanger, greatly reducing 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 following briefly introduces the drawings required for use in the embodiments of the present application or the description of the prior art. 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 any creative work.

[0026] Figure 1 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 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 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 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 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 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] The following describes in detail embodiments of the present application, examples of which 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 this 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 this 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 this application.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0035] In order to make the purpose, technical solutions and advantages of this application more clear, this application is further described in detail below with reference to the accompanying drawings and embodiments.

[0036] Example 1

[0037] See also Figure 1 The following is a schematic diagram of the structure of a mixed-fluid low-temperature, high-pressure hydrogen storage system using a cold-carrying cycle, provided in an embodiment of the present application. The system includes a mixed-fluid main cold-carrying cycle, a cold-carrying cycle, and a hydrogen circuit. The specific structures of each component are 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 includes 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 secondary cooling cycle is used to transfer the cold energy generated by the mixed working medium main cooling cycle to the hydrogen circuit. The secondary cooling cycle includes a secondary cooling compressor 201, a first aftercooler 202, a hydrogen cooling heat exchanger 203, a secondary cooling throttling element 204 and a tank cooler 205.

[0040] The hydrogen circuit includes a multi-stage hydrogen compressor 301 , a second 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-carrying cycle provided in Example 1 operates as follows:

[0042] After being pressurized by the mixed working fluid compressor 101, the mixed working fluid 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 is throttled, cooled and reduced in pressure 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 capacity. After being reheated in the mixed working fluid regenerator 103, the low-pressure mixed working fluid 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 first aftercooler 202 and is cooled to 77 K ~ 150 K 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 enters the tank cooler 205 and the hydrogen cooling heat exchanger 203 in turn to provide cooling capacity, and returns to the cooling compressor 201 after reheating to complete the cooling cycle.

[0044] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor 301 and then enters the second aftercooler 302 for cooling to form high-pressure hydrogen. The high-pressure hydrogen enters the hydrogen cooling heat exchanger 203 and is cooled to the hydrogen storage temperature to form low-temperature high-pressure hydrogen. The low-temperature high-pressure hydrogen then enters the low-temperature and high-pressure storage tank 304 for storage. The heat capacity of the low-temperature and high-pressure storage tank 304 itself and the compression heat generated by the low-temperature and high-pressure hydrogen being charged into the low-temperature and 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 carrier cooling cycle provided in the above-mentioned embodiment 1 of the present invention adopts mixed working fluid throttling refrigeration technology to couple the carrier cooling cycle, and transfers the cold generated by the mixed working fluid main cooling cycle to the hydrogen circuit through the carrier cooling cycle, so that the mixed working fluid main cooling cycle maintains a high efficiency while well matching the high-pressure hydrogen distributed cooling to meet the constant temperature cooling load of the low-temperature and high-pressure storage tank; and simplifies the complex multi-stream high-pressure heat exchanger with a large heat exchange load into a double-stream heat exchanger with a smaller heat exchange load, greatly reducing 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 further includes a pre-cooling unit 105 and a pre-cooling heat exchanger 106 .

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

[0051] The cooling medium is pressurized by the cooling compressor 201 and enters the first aftercooler 202 , and is precooled by the precooling heat exchanger 106 before entering the mixed medium reheater 103 .

[0052] The pre-cooling unit 105 is used to provide pre-cooling cooling capacity for the pre-cooling heat exchanger 106. The pre-cooling unit 105 can adopt, but is not limited to, a combination of one or more of a vapor compression refrigeration cycle, a mixed working fluid throttling refrigeration cycle, an absorption refrigeration cycle, an adsorption refrigeration cycle, and a commercial chiller.

[0053] Other working methods can refer to Example 1 and will not be described in detail here.

[0054] 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.

[0055] Example 3

[0056] 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.

[0057] The difference from Example 1 is 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.

[0058] Furthermore, the high-pressure hydrogen control valve group 303 includes a plurality of high-pressure hydrogen control valves connected in parallel. Figure 3 303a, 303b and 303c, 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. Figure 3 In 304a, 304b and 304c, the multiple 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 tank cooler 205, and any tank cooler 205 can cool the corresponding low-temperature and high-pressure storage tank, for example, the tank cooler 205a, the tank cooler 205b, and the 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.

[0059] Other working methods can refer to Example 1 and Example 2, which will not be described in detail here.

[0060] 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.

[0061] Example 4

[0062] 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.

[0063] 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 of the low-temperature and low-pressure cold-carrying working medium formed by cooling and reducing the pressure in the cold-carrying throttling element 204 into the tank cooler 205 can be controlled.

[0064] 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 rate 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.

[0065] Other working methods can refer to Examples 1 to 3 and will not be described in detail here.

[0066] The mixed refrigerant 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 cold-carrying refrigerant flow entering the tank cooler by setting a control valve group to achieve the adjustment of the cooling capacity distribution.

[0067] Example 5

[0068] 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.

[0069] The difference from Example 1 is that the refrigeration cycle also includes a refrigeration medium group 208, which 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.

[0070] Other working methods can refer to Examples 1 to 4 and will not be described in detail here.

[0071] 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 replenish lost nitrogen to ensure stable operation of the system.

[0072] Example 6

[0073] 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.

[0074] The difference from Example 5 is that the cold-carrying cycle also includes a cold-carrying working fluid storage tank 206 and a cold-carrying working fluid control valve group 207. The cold-carrying working fluid supplemented by the cold-carrying working fluid group 208 is stored in the cold-carrying working fluid storage tank 206, and then replenished into the cold-carrying cycle through the cold-carrying working fluid control valve group 207; the cold-carrying working fluid participating in the cycle can also be returned to the cold-carrying working fluid storage tank 206 through the cold-carrying working fluid control valve group 207 to achieve the regulation of the cold-carrying cycle working fluid flow and operating pressure.

[0075] Other working methods can refer to Examples 1 to 5, which will not be described in detail here.

[0076] The mixed-refrigerant low-temperature, high-pressure hydrogen storage system using a cold-carrying cycle, provided in Example 6 of the present invention, utilizes a cold-carrying-refrigerant storage tank and a control valve assembly to adjust the cyclic operating conditions, match variable loads, and improve system efficiency. It is understood that the various technical features of the above-described embodiments may be combined in any manner. To simplify the description, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there are no contradictions in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] The above are merely preferred embodiments of the present application and only specifically describe the technical principles of the present application. These descriptions are intended only to explain the principles of the present application and should not be construed in any way as limiting the scope of protection of the present application. Based on the explanations herein, any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application, as well as other specific implementations of the present application that can be conceived by those skilled in the art without inventive effort, shall be included within 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, characterized in that: include: Mixed working medium main cooling cycle, secondary cooling cycle and hydrogen circuit, including: The mixed working medium main cooling cycle is used to cool the cooling medium and provide refrigeration capacity for high-pressure hydrogen cooling. The mixed working medium main cooling cycle includes a mixed working medium compressor (101), a mixed working medium aftercooler (102), a mixed working medium regenerator (103) and a mixed working medium throttling element (104); The cold carrier cycle is used to transfer the cold energy generated by the mixed working medium main cold cycle to the hydrogen path, and the cold carrier cycle includes a cold carrier compressor (201), a first aftercooler (202), a hydrogen cooling heat exchanger (203), a cold carrier throttling element (204) and a tank cooler (205); The hydrogen circuit includes a multi-stage hydrogen compressor (301), a second aftercooler (302) and a low-temperature high-pressure storage tank (304); The mixed working medium is pressurized by the mixed working medium compressor (101) and enters the mixed working medium aftercooler (102). It is cooled to room temperature in the mixed working medium aftercooler (102) to form a high-pressure mixed working medium. The high-pressure mixed working medium then enters the mixed working medium regenerator (103) and is cooled by the low-pressure mixed working medium. It is then throttled, cooled, and depressurized in the mixed working medium throttling element (104) to form a low-pressure mixed working medium. The low-pressure mixed working medium then returns to the mixed working medium regenerator (103) and provides cooling capacity. The low-pressure mixed working medium is then reheated in the mixed working medium regenerator (103) and returns to the mixed working medium compressor (101) to complete the cycle. The cooling medium is pressurized by the cooling compressor (201) and enters the first aftercooler (202). The low-pressure mixed medium is cooled to 77 K to 150 K 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 reheating to complete the cooling cycle. The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor (301) and then enters the second 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 charged 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 according to claim 1, characterized in that: The mixed working medium main cooling cycle also includes a pre-cooling unit (105) and a pre-cooling heat exchanger (106). The mixed working medium is pressurized by the mixed working medium compressor (101), enters the mixed working medium aftercooler (102), and is cooled to room temperature in the mixed working medium aftercooler (102) to form a high-pressure mixed working medium. The high-pressure mixed working medium enters the precooling heat exchanger (106) for precooling, and then enters the mixed working medium reheater (103); The cooling medium is pressurized by the cooling compressor (201), enters the first aftercooler (202), is precooled by the precooling heat exchanger (106), and then enters the mixed medium reheater (103); The pre-cooling unit (105) is used to provide pre-cooling cooling capacity for the pre-cooling heat exchanger (106), and the pre-cooling unit (105) adopts a combination of one or more of a vapor 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 according to claim 1, characterized in that: 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.

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

5. The mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold cycle according to claim 1, characterized in that: The cold-carrying cycle further comprises a tank cooler shut-off valve and a tank cooler bypass valve. Under the regulation of the tank cooler shut-off valve and the tank cooler bypass valve, the flow rate of the low-temperature and low-pressure cold-carrying medium formed by reducing the temperature and pressure in the cold-carrying throttling element (204) into the tank cooler (205) can be controlled.

6. The mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold cycle according to claim 1, characterized in that: The cold-carrying cycle further comprises a cold-carrying medium group (208), wherein the cold-carrying medium group (208) is used in the form of PSA, membrane separation, steel cylinder or small air separation distillation tower to supplement the cold-carrying medium lost during the operation of the cold-carrying cycle.

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

8. The mixed working fluid low-temperature and high-pressure hydrogen storage system using a cold cycle according to claim 1, characterized in that: The cooling medium used in the cooling cycle includes at least one of nitrogen, air, argon, neon, helium, hydrogen, methane, ethane, propane, R14 or natural gas.

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