Hydraulic drive hydrogen compressor oil cylinder circulation system and hydraulic oil replacement method

Abstract

The invention provides a hydraulic drive hydrogen compressor oil cylinder circulation system and a hydraulic oil replacement method.The oil cylinder circulation system comprises a hydraulic drive hydrogen compressor, a hydraulic drive assembly, a heater and an oil replacement assembly, and the hydraulic drive assembly provides hydraulic oil for the hydraulic drive hydrogen compressor so as to drive the hydraulic drive hydrogen compressor to work; the oil changing assembly comprises an oil changing pipeline and an oil changing control valve, the oil changing pipeline is connected with at least one of the first cavity and the second cavity and the oil tank, and the oil changing control valve is arranged on the oil changing pipeline and used for controlling connection and disconnection of the oil changing pipeline. When the temperature of the hydraulic oil is low, the heater and an oil pump of the hydraulic driving assembly are started, and an oil change control valve is controlled to be opened, so that the hydraulic oil heated by the heater enters the liquid-driven hydrogen compressor under the action of the oil pump, and the hydraulic oil originally located in the liquid-driven hydrogen compressor is replaced into an oil tank through an oil change pipeline; therefore, when the liquid-driven hydrogen compressor is started, hydraulic oil entering the liquid-driven hydrogen compressor is at the normal working temperature, and when the low-temperature hydraulic oil in the liquid-driven hydrogen compressor is replaced, the liquid-driven hydrogen compressor does not need to be started. The problems that a hydraulic drive hydrogen compressor oil cylinder circulating system is difficult to start under the low-temperature condition and damage is caused to equipment are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of compressor hydraulic systems, and particularly relates to a cylinder circulation system for a liquid-driven hydrogen compressor and a method for replacing hydraulic oil. Background Art

[0002] The liquid-driven hydrogen compressor equipment consists of two parts: a hydraulic station and a compressor. The hydraulic station provides pressure for the compressor to drive the compressor to work, and the compressor provides power for gas pressurization.

[0003] Generally, the liquid-driven hydrogen compressor equipment is arranged in open-air environments such as stations. In areas with large temperature differences between winter and day and night in the north, the ambient temperature at night is low. Hydraulic oil has viscosity characteristics, and its viscosity changes with temperature. In the case of low ambient temperature, the equipment is not started at night, the viscosity of the hydraulic oil increases, and the fluidity decreases. The hydraulic oil in the cylinder of the liquid-driven hydrogen compressor has reduced fluidity at low temperatures. In this case, it will cause poor circulation in the compressor hydraulic system, difficult startup, and abnormal startup of the equipment for a long time, which will damage the equipment, greatly reduce the service life of the equipment, and in severe cases, will cause the equipment to be scrapped and the production to stop. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that the existing cylinder circulation system of the liquid-driven hydrogen compressor is prone to damage the equipment during startup at low temperatures.

[0005] To solve the above technical problems, the present invention provides a cylinder circulation system for a liquid-driven hydrogen compressor, including a liquid-driven hydrogen compressor, a hydraulic drive assembly, a heater, and an oil change assembly; the liquid-driven hydrogen compressor includes a cylinder block, a drive-side piston, and a drive rod. The drive-side piston is movably arranged in the cylinder block and divides the interior of the cylinder block into a first cavity and a second cavity. The drive rod is connected to the drive-side piston; the hydraulic drive assembly includes an oil tank, an oil pump, an inlet control valve, and an inlet pipeline. The inlet pipeline is connected to the oil tank, the first cavity, and the second cavity. The oil pump and the inlet control valve are both connected to the inlet pipeline, and the oil pump is arranged between the inlet control valve and the oil tank; the inlet control valve is used to control the communication between the oil tank and the first cavity or the second cavity through the inlet pipeline; the heater is arranged in the oil tank and is used to heat the hydraulic oil in the oil tank; the oil change assembly includes an oil change pipeline and an oil change control valve. The oil change pipeline is connected to at least one of the first cavity and the second cavity and the oil tank. When the inlet pipeline communicates with the first cavity, the oil change pipeline at least communicates with the first cavity, or when the inlet pipeline communicates with the second cavity, the oil change pipeline at least communicates with the second cavity; the oil change control valve is arranged on the oil change pipeline to control the on-off of the oil change pipeline.

[0006] In some embodiments of the present application, the oil change pipeline is connected to both the first cavity and the second cavity, and the oil change control valve can control the communication between the first cavity and the fuel tank and the communication between the second cavity and the fuel tank.

[0007] In some embodiments of the present application, the oil change pipeline includes a first oil change pipeline and a second oil change pipeline. The first oil change pipeline connects the first cavity and the fuel tank, and the second oil change pipeline connects the second cavity and the fuel tank. The oil change control valve includes a first oil change control valve and a second oil change control valve. The first oil change control valve is connected in series on the first oil change pipeline to control the on-off of the first oil change pipeline, and the second oil change control valve is connected in series on the second oil change pipeline to control the on-off of the second oil change pipeline.

[0008] In some embodiments of the present application, the cylinder block is provided with a first oil port, a second oil port, a third oil port, and a fourth oil port. The first oil port and the second oil port are arranged at intervals and are both connected to the first cavity. The third oil port and the fourth oil port are arranged at intervals and are both connected to the second cavity. The first oil port and the third oil port are respectively connected to the oil inlet pipeline, and the second oil port and the fourth oil port are connected to the oil change pipeline.

[0009] In some embodiments of the present application, the oil inlet control valve is a reversing valve. The oil inlet control valve includes a first interface, a second interface, a third interface, and a fourth interface. The oil inlet control valve can be switched to a first state in which the first interface is connected to the second interface, and the third interface is connected to the fourth interface, or switched to a second state in which the first interface is connected to the third interface, and the second interface is connected to the fourth interface. The oil inlet pipeline includes a first pipeline, a second pipeline, a third pipeline, and a fourth pipeline. The first pipeline connects the fuel tank and the first interface, the second pipeline connects the second interface and the first cavity, the third pipeline connects the third interface and the second cavity, and the fourth pipeline connects the fourth interface and the fuel tank. The oil pump is connected in series on the first pipeline.

[0010] In some embodiments of the present application, the oil inlet control valve can also be switched to a third state in which the first interface, the second interface, the third interface, and the fourth interface are all not connected to each other. The hydraulic drive assembly further includes an overflow pipeline and an overflow valve. The overflow pipeline is connected to the first pipeline and the fuel tank, and the overflow valve is arranged on the overflow pipeline.

[0011] In some embodiments of the present application, the hydraulic drive assembly further includes a check valve and an accumulator. The check valve is connected in series on the first pipeline and is located between the oil pump and the oil inlet control valve. The accumulator is connected to the first pipeline and is located between the check valve and the oil inlet control valve.

[0012] In some embodiments of the present application, the hydraulic drive assembly further includes a cooler, and the cooler is disposed on the fourth pipeline or the fuel tank.

[0013] In some embodiments of the present application, the hydraulic drive hydrogen compressor oil cylinder circulation system further includes a temperature sensor, and the temperature sensor is disposed in the fuel tank, and the temperature sensor is used to detect the temperature of the hydraulic oil in the fuel tank.

[0014] A method for replacing hydraulic oil by using the hydraulic drive hydrogen compressor oil cylinder circulation system described above, comprising:

[0015] Obtaining the temperature of the hydraulic oil detected by the temperature sensor, and when the temperature of the hydraulic oil is lower than a first preset temperature value, controlling the heater to start;

[0016] When the temperature of the hydraulic oil is higher than a second preset temperature value or after the heater has been started for a set time, controlling the oil change control valve to open and starting the oil pump; the second preset temperature value is greater than the first preset temperature value;

[0017] After the oil pump has operated for a preset time, controlling the oil change control valve to close and starting the hydraulic drive hydrogen compressor.

[0018] As can be seen from the above technical solutions, the beneficial effects of the present invention are:

[0019] The cylinder circulation system of the liquid-driven hydrogen compressor of the present application includes a liquid-driven hydrogen compressor, a hydraulic drive assembly, a heater, and an oil change assembly. The hydraulic drive assembly is connected to the liquid-driven hydrogen compressor and provides hydraulic oil to drive the liquid-driven hydrogen compressor to work. The heater is connected to the fuel tank and heats the hydraulic oil. The oil change assembly includes an oil change pipeline and an oil change control valve. The oil change pipeline is connected to at least one of the first cavity and the second cavity and the fuel tank, and the first cavity or the second cavity communicated with the oil change pipeline is communicated with the fuel tank through an oil inlet pipeline, so that a circulation loop is formed among the fuel tank, the liquid-driven hydrogen compressor, and the oil change pipeline. The oil change control valve is arranged on the oil change pipeline. When the temperature of the hydraulic oil is relatively low, by starting the heater and the oil pump of the hydraulic drive assembly and controlling the oil change control valve to open, the hydraulic oil heated by the heater enters the liquid-driven hydrogen compressor under the action of the oil pump, and the hydraulic oil originally in the liquid-driven hydrogen compressor is replaced into the fuel tank through the oil change pipeline, so as to realize the replacement of the low-temperature hydraulic oil in the liquid-driven hydrogen compressor with the hydraulic oil at the normal working temperature, so that the hydraulic oil entering the liquid-driven hydrogen compressor when the liquid-driven hydrogen compressor starts is at the normal working temperature, and when replacing the low-temperature hydraulic oil in the liquid-driven hydrogen compressor, it is not necessary to start the liquid-driven hydrogen compressor, avoiding the problems of difficult start-up of the cylinder circulation system of the liquid-driven hydrogen compressor at low temperature and damage to the equipment. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of the cylinder circulation system of the liquid-driven hydrogen compressor in an embodiment.

[0021] Figure 2 It is a schematic structural diagram of the liquid-driven hydrogen compressor in an embodiment.

[0022] Figure 3 It is a schematic structural diagram of the hydraulic drive assembly in an embodiment.

[0023] Figure 4 It is a schematic structural diagram of the oil inlet control valve in an embodiment.

[0024] Figure 5 It is a schematic structural diagram of the oil pump in an embodiment.

[0025] Figure 6 It is a schematic structural diagram of the oil change assembly in an embodiment.

[0026] The descriptions of the reference numerals in the drawings are as follows: 1 - liquid-driven hydrogen compressor; 11 - cylinder block; 111 - liquid cavity; 1111 - first cavity; 1112 - second cavity; 112 - hydrogen cavity; 113 - intake port; 114 - outlet port; 115 - first oil port; 116 - second oil port; 117 - third oil port; 118 - fourth oil port; 12 - drive-side piston; 13 - drive rod; 14 - hydrogen-side piston; 15 - intake check valve; 16 - outlet check valve; 2 - hydraulic drive assembly; 21 - fuel tank; 22 - oil pump; 221 - motor; 222 - hydraulic pump; 223 - pump stand; 224 - shock absorber; 23 - inlet oil control valve; 231 - first interface; 232 - second interface; 233 - third interface; 234 - fourth interface; 24 - inlet oil pipeline; 241 - first pipeline; 242 - second pipeline; 243 - third pipeline; 244 - fourth pipeline; 25 - overflow pipeline; 26 - overflow valve; 3 - heater; 4 - oil change assembly; 41 - oil change pipeline; 411 - first oil change pipeline; 412 - second oil change pipeline; 42 - oil change control valve; 421 - first oil change control valve; 422 - second oil change control valve; 51 - check valve; 52 - accumulator; 53 - control valve; 54 - inlet oil filter; 55 - return oil filter; 56 - pressure transmitter; 57 - pressure gauge; 58 - cooler; 61 - temperature sensor; 62 - magnetic bar; 63 - air filter; 64 - liquid supplement control valve; 65 - liquid level controller; 66 - liquid level gauge. Detailed implementation manners

[0027] Typical implementation manners reflecting the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different implementation manners, all of which do not depart from the scope of the present invention, and the descriptions and illustrations therein are for illustrative purposes in nature and not for limiting the present invention.

[0028] In the description of the present application, it should be understood that in the embodiments shown in the drawings, the indication of the direction or position relationship (such as up, down, left, right, front, and back, etc.) is 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. When these elements are in the positions shown in the drawings, these descriptions are appropriate. If the description of the positions of these elements changes, then the indication of these directions also changes accordingly.

[0029] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0030] The existing cylinder circulation system of the liquid-driven hydrogen compressor usually only includes a liquid-driven hydrogen compressor and a hydraulic drive component. The hydraulic drive component is connected to the liquid-driven hydrogen compressor and provides working power for the liquid-driven hydrogen compressor, so that the liquid-driven hydrogen compressor continuously pressurizes hydrogen. However, the existing liquid-driven hydrogen compressor cannot replace the hydraulic oil inside it when it is not started. Moreover, when the hydraulic oil has an increased viscosity and low fluidity at low temperatures, it will cause poor circulation and difficult startup of the cylinder circulation system of the liquid-driven hydrogen compressor. If the equipment fails to start properly for a long time, it will cause damage to the equipment, greatly reducing the service life of the equipment. In severe cases, it will cause the equipment to be scrapped and the production to stop.

[0031] Refer to Figure 1 , in view of the above situation, the present application proposes a cylinder circulation system for a liquid-driven hydrogen compressor, which includes a liquid-driven hydrogen compressor 1, a hydraulic drive component 2, a heater 3 and an oil change component 4. The hydraulic drive component 2 is connected to the liquid-driven hydrogen compressor 1 and provides working power for the liquid-driven hydrogen compressor 1. The heater 3 can be an electric heater or a heat exchanger, and the heater 3 of the present application is preferably an explosion-proof electric heater 3. The heater 3 is arranged in the oil tank 21 of the hydraulic drive component 2 and is used to heat the hydraulic oil in the oil tank 21. The oil change component 4 includes an oil change pipeline 41 and an oil change control valve 42. The oil change pipeline 41 is connected to the liquid-driven hydrogen compressor 1, and the oil change control valve 42 is arranged on the oil change pipeline 41 and is used to control the on-off of the oil change pipeline 41. When the temperature of the hydraulic oil in the liquid-driven hydrogen compressor 1 is too low, by controlling the oil change control valve 42 to open and controlling the hydraulic drive component 2 to work, the hydraulic drive component 2 is controlled to provide hydraulic oil at an appropriate temperature for the liquid-driven hydrogen compressor 1 and replace the low-temperature hydraulic oil originally in the liquid-driven hydrogen compressor 1, so that the hydraulic oil inside the liquid-driven hydrogen compressor 1 has a higher temperature when starting.

[0032] Among them, when replacing the hydraulic oil in the liquid-driven hydrogen compressor 1, the liquid-driven hydrogen compressor 1 does not need to perform actions, that is, the cylinder circulation system of the liquid-driven hydrogen compressor can replace the hydraulic oil in the liquid-driven hydrogen compressor 1 without starting the liquid-driven hydrogen compressor 1, avoiding the problems of difficult startup and damage to the equipment caused by the increased viscosity and reduced fluidity of the hydraulic oil in the cylinder circulation system of the liquid-driven hydrogen compressor at low temperatures.

[0033] Specifically, refer to Figure 2, the liquid-driven hydrogen compressor 1 includes a cylinder block 11, a driving-side piston 12, a driving rod 13, and a hydrogen-side piston 14. A liquid cavity 111 and a hydrogen cavity 112 are provided on the cylinder block 11. The driving-side piston 12 is slidably connected inside the liquid cavity 111 of the cylinder block 11 and divides the liquid cavity 111 of the cylinder block 11 into a first cavity 1111 and a second cavity 1112. The hydrogen-side piston 14 is slidably connected inside the hydrogen cavity 112 of the cylinder block 11, and the driving rod 13 connects the driving-side piston 12 and the hydrogen-side piston 14. The cylinder block 11 is provided with an air inlet 113 and an air outlet 114 at the hydrogen cavity 112. An intake check valve 15 is provided at the air inlet 113. The intake check valve 15 is used to restrict the gas to flow only in the direction of entering the hydrogen cavity 112. An exhaust check valve 16 is provided at the air outlet 114. The exhaust check valve 16 is used to restrict the gas to flow only in the direction of discharging from the hydrogen cavity 112.

[0034] The working principle of the liquid-driven hydrogen compressor 1 is as follows: When hydraulic oil enters the first cavity 1111, the pressure oil pushes the driving-side piston 12 to move towards the second cavity 1112. Thus, the driving-side piston 12 drives the hydrogen-side piston 14 to move through the driving rod 13, causing the volume of the hydrogen cavity 112 to increase and form a negative pressure. Under the action of the negative pressure, hydrogen is sucked into the hydrogen cavity 112. When hydraulic oil enters the second cavity 1112, the pressure oil pushes the driving-side piston 12 to move towards the first cavity 1111. Thus, the driving-side piston 12 drives the hydrogen-side piston 14 to move through the driving rod 13, causing the volume of the hydrogen cavity 112 to decrease and compressing and boosting the hydrogen inside the hydrogen cavity 112. In this way, by driving the driving-side piston 12 to reciprocate inside the liquid cavity 111 with hydraulic oil, continuous boosting of hydrogen is achieved.

[0035] In Figure 2In the illustrated embodiment, there are two hydrogen chambers 112, and the two hydrogen chambers 112 are respectively located on both sides of the liquid chamber 111 in the axial direction. A hydrogen-side piston 14 is slidably connected inside each hydrogen chamber 112. The middle of the driving rod 13 is fixedly connected to the driving-side piston 12, and the two ends of the driving rod 13 are respectively connected to the hydrogen-side pistons 14 located in the two hydrogen chambers 112, so that the driving rod 13 drives the two hydrogen-side pistons 14 to move simultaneously. When the pressure oil pushes the driving-side piston 12 to move towards the second chamber 1112, the volume of the hydrogen chamber 112 close to the first chamber 1111 increases to form a negative pressure, causing hydrogen to be inhaled into it under the action of the negative pressure. The hydrogen in the hydrogen chamber 112 close to the second chamber 1112 is pressurized by the extrusion of the hydrogen-side piston 14 and discharged from the hydrogen chamber 112; conversely, when the pressure oil pushes the driving-side piston 12 to move towards the first chamber 1111, the volume of the hydrogen chamber 112 close to the second chamber 1112 increases to form a negative pressure, causing hydrogen to be inhaled into it under the action of the negative pressure. The hydrogen in the hydrogen chamber 112 close to the first chamber 1111 is pressurized by the extrusion of the hydrogen-side piston 14 and discharged from the hydrogen chamber 112. In this way, the driving-side piston 12 is driven by the hydraulic oil to reciprocate in the liquid chamber 111, thereby realizing continuous pressurization of hydrogen, and realizing double pressurization of hydrogen during one reciprocating movement of the driving-side piston 12, improving the pressurization efficiency.

[0036] In other embodiments, the positions of the hydrogen chamber 112 and the liquid chamber 111 are interchanged, that is, there are two liquid chambers 111, and the two liquid chambers 111 are respectively located on both sides of the hydrogen chamber 112 in the axial direction. A driving-side piston 12 is slidably connected inside each liquid chamber 111. The middle of the driving rod 13 is fixedly connected to the hydrogen-side piston 14, and the two ends of the driving rod 13 are respectively connected to the driving-side pistons 12 located in the two liquid chambers 111, so that the two driving-side pistons 12 and the hydrogen-side piston 14 move synchronously, so that when the hydraulic oil drives the driving-side piston 12 to move, it drives the hydrogen-side piston 14 to compress hydrogen. Or, only one liquid chamber 111 and one hydrogen chamber 112 are provided, that is, Figure 2 One hydrogen chamber 112 on one side of the liquid chamber 111 of the liquid-driven hydrogen compressor 1 is removed.

[0037] It should be noted that the cylinder block 11 provided with the liquid chamber 111 and the hydrogen chamber 112 can be an integral structure, that is, the liquid chamber 111 and the hydrogen chamber 112 are simultaneously provided on one cylinder block 11. The cylinder block 11 provided with the liquid chamber 111 and the hydrogen chamber 112 can also be a split structure, that is, the cylinder block 11 includes a separately arranged liquid cylinder block and a hydrogen cylinder block, and the hydrogen cylinder block is fixedly connected to the liquid cylinder block. Among them, the hydrogen-side piston 14 is correspondingly arranged with the hydrogen cylinder block.

[0038] The cylinder block 11 is provided with a first oil port 115, a second oil port 116, a third oil port 117 and a fourth oil port 118. The first oil port 115 and the second oil port 116 are arranged at intervals and are both communicated with the first cavity 1111. The third oil port 117 and the fourth oil port 118 are arranged at intervals and are both communicated with the second cavity 1112. The first oil port 115 and the third oil port 117 are used to connect with the hydraulic drive assembly 2, so as to realize that the hydraulic drive assembly 2 provides hydraulic oil for the first cavity 1111 or the second cavity 1112. The second oil port 116 and the fourth oil port 118 are used to connect with the oil change pipeline 41, so as to realize discharging the hydraulic oil in the first cavity 1111 or the hydraulic oil in the second cavity 1112. In some embodiments, only one of the second oil port 116 and the fourth oil port 118 may be provided.

[0039] Preferably, the first oil port 115 and the second oil port 116 are arranged on opposite sides of the first cavity 1111, so that the hydraulic oil entering the first cavity 1111 from the first oil port 115 pushes the hydraulic oil originally stored in the first cavity 1111 in a direction exactly towards the second oil port 116. Therefore, the hydraulic oil originally stored in the first cavity 1111 first flows out from the second oil port 116, improving the replacement effect of the hydraulic oil. Similarly, the third oil port 117 and the fourth oil port 118 are arranged on opposite sides of the second cavity 1112, so that the hydraulic oil entering the second cavity 1112 from the third oil port 117 pushes the hydraulic oil originally stored in the second cavity 1112 in a direction exactly towards the fourth oil port 118. Therefore, the hydraulic oil originally stored in the second cavity 1112 first flows out from the fourth oil port 118, improving the replacement effect of the hydraulic oil.

[0040] Refer to 1 and Figure 3 As shown in FIGS. 1 and, the hydraulic drive assembly 2 includes an oil tank 21, an oil pump 22, an oil inlet control valve 23 and an oil inlet pipeline 24. The oil inlet pipeline 24 is connected to the oil tank 21, the first cavity 1111 and the second cavity 1112. The oil pump 22 and the oil inlet control valve 23 are both connected to the oil inlet pipeline 24, and the oil pump 22 is arranged between the oil inlet control valve 23 and the oil tank 21; the oil inlet control valve 23 is used to control the communication between the oil tank 21 and the first cavity 1111 or the second cavity 1112 through the oil inlet pipeline 24, so that the oil tank 21 can provide hydraulic oil for the first cavity 1111 and can also provide hydraulic oil for the second cavity 1112.

[0041] In Figure 1 、 Figure 2 and Figure 4In the illustrated embodiment, the oil inlet control valve 23 is a reversing valve; the oil inlet control valve 23 includes a first interface 231, a second interface 232, a third interface 233, and a fourth interface 234; the oil inlet control valve 23 can be switched to a first state in which the first interface 231 communicates with the second interface 232 and the third interface 233 communicates with the fourth interface 234, or switched to a second state in which the first interface 231 communicates with the third interface 233 and the second interface 232 communicates with the fourth interface 234.

[0042] The oil inlet pipeline 24 includes a first pipeline 241, a second pipeline 242, a third pipeline 243, and a fourth pipeline 244. The first pipeline 241 connects the oil tank 21 and the first interface 231. The second pipeline 242 connects the second interface 232 and a first oil port 115 that communicates with the first cavity 1111. The third pipeline 243 connects the third interface 233 and a third oil port 117 that communicates with the second cavity 1112. The fourth pipeline 244 connects the fourth interface 234 and the oil tank 21. The oil pump 22 is connected in series on the first pipeline 241.

[0043] During the normal operation of the liquid-driven hydrogen compressor 1, when the oil inlet control valve 23 is switched to the first state in which the first interface 231 communicates with the second interface 232 and the third interface 233 and the fourth interface 234 communicate, and the oil pump 22 is in the working state, the hydraulic oil inside the oil tank 21, under the action of the oil pump 22, sequentially passes through the first pipeline 241, the oil inlet control valve 23, and the second pipeline 242 and enters the first cavity 1111. The hydraulic oil in the second cavity 1112 returns to the oil tank 21 through the third pipeline 243 and the fourth pipeline 244, thereby realizing the movement of the driving-side piston 12 in the direction of the second cavity 1112. When the oil inlet control valve 23 is switched to the second state in which the first interface 231 communicates with the third interface 233 and the second interface 232 and the fourth interface 234 communicate, and the oil pump 22 is in the working state, the oil pump 22 pumps the hydraulic oil inside the oil tank 21, which, under the action of the oil pump 22, sequentially passes through the first pipeline 241, the oil inlet control valve 23, and the third pipeline 243 and enters the second cavity 1112. The hydraulic oil in the first cavity 1111 returns to the oil tank 21 through the second pipeline 242 and the fourth pipeline 244, thereby realizing the movement of the driving-side piston 12 in the direction of the first cavity 1111. By controlling the oil inlet control valve 23 to repeatedly switch between the first state and the second state, the continuous operation of the liquid-driven hydrogen compressor 1 is realized.

[0044] The inlet oil control valve 23 can also switch to a third state in which the first interface 231, the second interface 232, the third interface 233, and the fourth interface 234 are all not connected to each other. When the inlet oil control valve 23 is in the third state, the hydraulic hydrogen compressor 1 is in a standby state, and the first cavity 1111 and the second cavity 1112 are in a pressure-holding state, so that the hydrogen gas entering the hydrogen cavity 112 cannot push the driving-side piston 12 to move, avoiding the driving-side piston 12 from moving under the action of external forces (such as hydrogen gas pressure) in the environment of low-temperature hydraulic oil.

[0045] In other embodiments, an inlet oil pipeline and an oil return pipeline are provided between the first cavity 1111 and the fuel tank 21 and between the second cavity 1112 and the fuel tank 21, and the two inlet oil pipelines are both connected to the fuel tank 21 through an oil pump 22. The inlet oil control valve 23 includes four stop valves, which are respectively arranged on the two inlet oil pipelines and the two oil return pipelines. Thus, through the control of the four stop valves, the hydraulic drive assembly 2 can also provide hydraulic oil for the operation of the hydraulic hydrogen compressor 1.

[0046] The hydraulic drive assembly 2 further includes an overflow pipeline 25 and an overflow valve 26. The overflow pipeline 25 is connected to the first pipeline 241 and the fuel tank 21, and the overflow valve 26 is arranged on the overflow pipeline 25. The overflow valve 26 can set the maximum hydraulic pressure. When the hydraulic pressure in the first pipeline 241 exceeds the set maximum hydraulic pressure, part of the hydraulic oil flows back to the fuel tank 21 through the overflow pipeline 25, so that the hydraulic pressure in the first pipeline 241 is maintained within a safe value. Especially when the inlet oil control valve 23 is in the third state, the first pipeline 241, the overflow pipeline 25, and the fuel tank 21 form an internal circulation structure, so that the pressure of the hydraulic hydrogen compressor cylinder circulation system is maintained within a safe pressure range.

[0047] In an alternative embodiment, when the inlet oil control valve 23 is in the third state, the first interface 231 and the fourth interface 234 can also be in a connected state, so that the hydraulic oil in the first pipeline 241 flows back to the fuel tank 21 through the first interface 231 and the fourth interface 234 of the inlet oil control valve 23 and then through the fourth pipeline 244.

[0048] Wherein, one end of the overflow pipeline 25 far away from the first pipeline 241 can be directly connected to the fourth pipeline 244, so that the required pipeline length of the overflow pipeline 25 can be shortened.

[0049] Refer to Figure 5, the oil pump 22 includes a motor 221, a hydraulic pump 222, a pump frame 223, and shock absorbers 224. A plurality of shock absorbers 224 are provided on the pump frame 223 at intervals, and the pump frame 223 is connected to the site or component where the oil pump 22 is installed through the shock absorbers 224. The motor 221 and the hydraulic pump 222 are both fixed on the pump frame 223, and the rotating shaft of the hydraulic pump 222 is drivingly connected to the output shaft of the motor 221, so that the motor 221 drives the hydraulic pump 222 to work. Moreover, the vibration generated when the motor 221 and the hydraulic pump 222 work is absorbed by the shock absorbers 224, avoiding damage to the site where the oil pump 22 is installed and reducing noise. The hydraulic pump 222 is connected in series to the first pipeline 241, so that when the hydraulic pump 222 works, it can pump the hydraulic oil in the fuel tank 21 to the liquid-driven hydrogen compressor 1. It should be noted that the oil pump 22 may also only include the motor 221 and the hydraulic pump 222, without setting the pump frame 223 and the shock absorbers 224. The motor 221 and the hydraulic pump 222 can be connected through a coupling or directly connected.

[0050] For example, the pump frame 223 is in a flat plate structure, and shock absorbers 224 are provided at the four corners of the bottom surface, and the pump frame 223 is supported by the shock absorbers 224. The motor 221 and the hydraulic pump 222 are fixed on the top surface of the pump frame 223, and the vibration generated when the motor 221 and the hydraulic pump 222 work is absorbed by the shock absorbers 224 and will not be transmitted to the ground.

[0051] Refer to Figure 1 and Figure 2 , the hydraulic drive assembly 2 further includes a check valve 51. The check valve 51 is connected in series to the first pipeline 241 and is located between the oil pump 22 and the inlet control valve 23, to prevent the hydraulic oil in the liquid-driven hydrogen compressor 1 from flowing back through the first pipeline 241 and returning to the fuel tank 21.

[0052] The hydraulic drive assembly 2 further includes an accumulator 52. The accumulator 52 is connected to the first pipeline 241. The accumulator 52 is used to adjust the pressure of the hydraulic oil in the first pipeline 241, so that the pressure of the hydraulic oil entering the liquid-driven hydrogen compressor 1 is more stable. Preferably, the accumulator 52 is located between the check valve 51 and the inlet control valve 23, that is, the accumulator 52 is located on the side of the check valve 51 away from the oil pump 22, so that when the oil pump 22 stops working, the hydraulic oil in the accumulator 52 will not flow back to the fuel tank 21 through the first pipeline 241, thereby realizing the pressure holding of the accumulator 52.

[0053] A control valve 53 may also be connected in series between the accumulator 52 and the first pipeline 241. The control valve 53 is used to control the on-off between the accumulator 52 and the first pipeline 241. When the accumulator 52 needs to be replaced, by closing the control valve 53, the leakage of the hydraulic oil in the first pipeline 241 can be avoided when the accumulator 52 is replaced.

[0054] The hydraulic drive assembly 2 further includes an inlet oil filter 54. The inlet oil filter 54 is connected in series on the first pipeline 241 and is located between the oil pump 22 and the one-way valve 51, so that the hydraulic oil in the oil tank 21 and the oil pump 22 is filtered by the inlet oil filter 54, preventing impurities in the hydraulic oil from entering downstream equipment (such as the accumulator 52, the inlet control valve 23, and the liquid-driven hydrogen compressor 1) and causing damage. It should be noted that the inlet oil filter 54 can also be arranged at one end of the first pipeline 241 close to the oil tank 21, so that the hydraulic oil in the oil tank 21 passes through the inlet oil filter 54 and then passes through the oil pump 22.

[0055] In one embodiment, an oil return filter 55 is connected in series on the fourth pipeline 244, and the oil return filter 55 is arranged downstream of the overflow pipeline 25, so that the hydraulic oil discharged from the liquid-driven hydrogen compressor 1 and the hydraulic oil after passing through the overflow valve 26 both pass through the oil return filter 55. Thus, a single oil return filter 55 can filter the hydraulic oil discharged from the liquid-driven hydrogen compressor 1 and the hydraulic oil after passing through the overflow valve 26, eliminating the need to set up multiple oil return filters 55, simplifying the structure and reducing costs.

[0056] In one embodiment, the hydraulic oil passing through the oil change assembly 4 may not pass through the oil return filter 55. Since the hydraulic oil is only discharged from the oil change assembly 4 into the oil tank 21 when the temperature of the hydraulic oil is low, and the viscosity of the hydraulic oil is relatively large when the temperature is low, setting the hydraulic oil passing through the oil change assembly 4 not to pass through the oil return filter 55 reduces the possibility of the oil return filter 55 being blocked. When the liquid-driven hydrogen compressor 1 needs to be cleaned, the hydraulic oil in the liquid-driven hydrogen compressor 1 is directly discharged outside the oil tank 21 through the oil change assembly 4, and there is no need to filter the hydraulic oil passing through the oil change assembly 4 either.

[0057] The hydraulic drive assembly 2 further includes a pressure transmitter 56. The pressure transmitter 56 is connected to the first pipeline 241 and communicates with one end of the overflow pipeline 25 close to the first pipeline 241, enabling the pressure transmitter 56 to detect the pressure of the first pipeline 241, thereby accurately adjusting the set pressure value of the overflow valve 26 and accurately controlling the working pressure of the liquid-driven hydrogen compressor 1 according to the signal of the pressure transmitter 56.

[0058] In one embodiment, the hydraulic drive assembly 2 further includes a pressure gauge 57. The pressure gauge 57 is connected to the first pipeline 241, allowing the working pressure of the liquid-driven hydrogen compressor 1 to be visually obtained through the pressure gauge 57.

[0059] The hydraulic drive assembly 2 further includes a cooler 58, which is disposed on the fourth pipeline 244 or the fuel tank 21. During the continuous operation of the liquid-driven hydrogen compressor 1, heat is generated, resulting in an increase in the temperature of the hydraulic oil. The cooler 58 is connected in series to the fourth pipeline 244 or disposed inside the fuel tank 21, and the hydraulic oil is cooled by the cooler 58, so that the hydraulic oil maintains an optimal working temperature. The cooler 58 can be a heat exchanger or a semiconductor cooler.

[0060] The liquid-driven hydrogen compressor oil cylinder circulation system further includes a temperature sensor 61, which is disposed inside the fuel tank 21 and is used to detect the temperature of the hydraulic oil inside the fuel tank 21. When the temperature of the hydraulic oil is lower than the first preset temperature value set by the user, the heater 3 is started to heat the hydraulic oil. When the temperature of the hydraulic oil is higher than the third preset temperature value set by the user, the cooler 58 is started to cool the hydraulic oil. The third preset temperature value is greater than the first preset temperature value.

[0061] The interior of the fuel tank 21 is provided with a cavity for storing hydraulic oil. The heater 3 is disposed inside the cavity of the fuel tank 21, so that before replacing the hydraulic oil of the liquid-driven hydrogen compressor 1, the heater 3 is first started. After the hydraulic oil inside the fuel tank 21 is heated to the second preset temperature set by the user (the second preset temperature is greater than the first preset temperature and less than the third preset temperature value), the oil pump 22 is then started to replace the hydraulic oil of the liquid-driven hydrogen compressor 1. With such a setting, when the oil pump 22 is started, the temperature of the hydraulic oil entering the oil pump 22 is relatively high, the viscosity is relatively low, and the fluidity is large, thereby reducing the energy consumption of the oil pump 22.

[0062] The interior of the fuel tank 21 is further provided with a magnetic bar 62, which can adsorb metal debris in the hydraulic oil, prevent the metal debris from entering the interior of the liquid-driven hydrogen compressor 1 and affecting the movement of the driving-side piston 12, and prevent the metal debris from entering the interior of the liquid-driven hydrogen compressor 1 and easily causing damage to the driving-side piston 12.

[0063] The top surface or the upper side surface of the fuel tank 21 is provided with a pressure balance port communicating with the cavity of the fuel tank 21, and the pressure balance port is used to allow external air to enter the interior of the cavity, so as to balance the pressure inside and outside the fuel tank 21. Among them, an air filter 63 is provided on the pressure balance port of the fuel tank 21, so that the air entering the interior of the fuel tank 21 needs to pass through the filtration of the air filter 63, preventing dust in the air outside the fuel tank 21 from entering the interior of the fuel tank 21 and causing impurities to be mixed into the hydraulic oil.

[0064] The fuel tank 21 is connected through a pipeline to a storage tank for storing hydraulic oil, and the hydraulic oil in the storage tank is used to replenish the hydraulic oil in the fuel tank 21. A liquid replenishment control valve 64 is provided on the pipeline between the fuel tank 21 and the storage tank. A liquid level controller 65 is further provided inside the fuel tank 21, and the liquid level controller 65 is electrically connected to the liquid replenishment control valve 64. The liquid level controller 65 is used to detect the liquid level height of the hydraulic oil in the fuel tank 21 and control the opening and closing of the liquid replenishment control valve 64 through the liquid level controller 65, thereby controlling the on-off of the pipeline between the fuel tank 21 and the storage tank. When the hydraulic oil in the fuel tank 21 is lower than the set height, the liquid level controller 65 controls the liquid replenishment control valve 64 to open, so that the hydraulic oil inside the storage tank is automatically replenished into the fuel tank 21. When the height of the hydraulic oil in the fuel tank 21 reaches the set height, the liquid level controller 65 controls the liquid replenishment control valve 64 to close, and stops replenishing the hydraulic oil to the fuel tank 21.

[0065] In one embodiment, a liquid level gauge 66 is provided on the fuel tank 21, and the user can intuitively know the amount of hydraulic oil in the fuel tank 21 through the liquid level gauge 66.

[0066] Refer to Figure 6 , the oil change pipeline 41 of the oil change assembly 4 is connected to the fuel tank 21 and is also connected to at least one of the first cavity 1111 and the second cavity 1112. Moreover, when the oil inlet pipeline communicates with the first cavity, the oil change pipeline communicates with at least the first cavity, so that the fuel tank 21, the oil inlet pipeline 24, the first cavity 1111, and the oil change pipeline 41 form a circulation channel; or when the oil inlet pipeline communicates with the second cavity, the oil change pipeline communicates with at least the second cavity, so that the fuel tank 21, the oil inlet pipeline 24, the second cavity 1112, and the oil change pipeline 41 form a circulation channel, or a circulation channel can be formed between the fuel tank 21, the oil inlet pipeline 24, the first cavity 1111, the oil change pipeline 41 and between the fuel tank 21, the oil inlet pipeline 24, the second cavity 1112, the oil change pipeline 41. An oil change control valve 42 is provided on the oil change pipeline 41 to control the on-off of the oil change pipeline 41. Moreover, when it is necessary to replace the hydraulic oil in the liquid-driven hydrogen compressor 1, the oil change control valve 42 is opened so that the first cavity 1111 or the second cavity 1112 communicates with the fuel tank 21 through the oil change pipeline 41, or both the first cavity 1111 and the second cavity 1112 communicate with the fuel tank 21 through the oil change pipeline 41. When it is not necessary to replace the hydraulic oil in the liquid-driven hydrogen compressor 1, the oil change control valve 42 is controlled to close so that the oil change pipeline 41 no longer communicates with the first cavity 1111, the second cavity 1112 and the fuel tank 21, so that the hydraulic oil can push the driving-side piston 12 to move so that the liquid-driven hydrogen compressor 1 works normally.

[0067] Specifically, the oil change pipeline 41 includes a first oil change pipeline 411 and a second oil change pipeline 412. The two ends of the first oil change pipeline 411 are respectively connected to the second oil port 116 of the first cavity 1111 and the fuel tank 21, and the two ends of the second oil change pipeline 412 are connected to the fourth oil port 118 of the second cavity 1112 and the fuel tank 21, that is, the oil change pipeline 41 is connected to both the first cavity 1111 and the second cavity 1112. The oil change control valve 42 includes a first oil change control valve 421 and a second oil change control valve 422. The first oil change control valve 421 is connected in series on the first oil change pipeline 411 to control the on-off of the first oil change pipeline 411, and the second oil change control valve 422 is connected in series on the second oil change pipeline 412 to control the on-off of the second oil change pipeline 412.

[0068] When it is necessary to replace the hydraulic oil in the first cavity 1111, control the first oil change control valve 421 to open, switch the oil inlet control valve 23 to the state where the first interface 231 is communicated with the second interface 232, and start the oil pump 22, so that the hydraulic oil in the fuel tank 21 enters the first cavity 1111 through the first pipeline 241 to replace the hydraulic oil in the first cavity 1111, and the replaced hydraulic oil flows back to the fuel tank 21 through the first oil change pipeline 411. When it is necessary to replace the hydraulic oil in the second cavity 1112, control the second oil change control valve 422 to open, switch the oil inlet control valve 23 to the state where the first interface 231 is communicated with the third interface 233, and start the oil pump 22, so that the hydraulic oil in the fuel tank 21 enters the second cavity 1112 through the first pipeline 241 to replace the hydraulic oil in the second cavity 1112, and the replaced hydraulic oil flows back to the fuel tank 21 through the second oil change pipeline 412. It should be noted that when replacing the hydraulic oil in the first cavity 1111, the second oil change control valve 422 can also be in the open state; when replacing the hydraulic oil in the second cavity 1112, the first oil change control valve 421 can also be in the open state. In this embodiment, the first oil change control valve 421 and the second oil change control valve 422 can both be globe valves, or the first oil change control valve 421 and the second oil change control valve 422 form an integrated three-position four-way directional control valve.

[0069] In one embodiment, when the liquid-driven hydrogen compressor 1 is in a shutdown state, the driving-side piston 12 is just at the position where the volume of the first cavity 1111 is zero or just at the position where the volume of the second cavity 1112 is zero. Therefore, when replacing the hydraulic oil in the liquid-driven hydrogen compressor 1, only the hydraulic oil in the corresponding cavity needs to be replaced. In this embodiment, the oil change pipeline 41 only needs to be connected to the corresponding cavity.

[0070] For example, the oil change pipeline 41 communicates with the second oil port 116 of the first cavity 1111. Each time the liquid-driven hydrogen compressor 1 stops, the oil inlet control valve 23 is controlled to switch to the first state where the first interface 231 communicates with the second interface 232, so that after each stop of the liquid-driven hydrogen compressor 1, the hydraulic oil stays in the first cavity 1111, and the volume of the second cavity 1112 is zero, that is, there is no hydraulic oil left in the second cavity 1112. When it is necessary to replace the hydraulic oil in the liquid-driven hydrogen compressor 1, the oil change control valve 42 is controlled to open, the oil inlet control valve 23 is switched to the first state where the first interface 231 communicates with the second interface 232, and the oil pump 22 is started, and then all the hydraulic oil in the liquid-driven hydrogen compressor 1 can be replaced. On the contrary, the oil change pipeline 41 communicates with the fourth oil port 118 of the second cavity 1112. Each time the liquid-driven hydrogen compressor 1 stops, the oil inlet control valve 23 is controlled to switch to the second state where the first interface 231 communicates with the third interface 233, so that after each stop of the liquid-driven hydrogen compressor 1, the hydraulic oil stays in the second cavity 1112, and the volume of the first cavity 1111 is zero, that is, there is no hydraulic oil left in the first cavity 1111. When it is necessary to replace the hydraulic oil in the liquid-driven hydrogen compressor 1, the oil change control valve 42 is controlled to open, the oil inlet control valve 23 is switched to the second state where the first interface 231 communicates with the third interface 233, and the oil pump 22 is started, and then all the hydraulic oil in the liquid-driven hydrogen compressor 1 can be replaced.

[0071] A method for replacing hydraulic oil in a cylinder circulation system of a liquid-driven hydrogen compressor includes the following steps:

[0072] S10: Obtain the temperature of the hydraulic oil detected by the temperature sensor 61, and when the temperature of the hydraulic oil is lower than the first preset temperature value, control the heater 3 to start. Among them, the first preset temperature value is set by the user. When the temperature of the hydraulic oil is lower than the first preset temperature value, the viscosity of the hydraulic oil is high and the fluidity is low.

[0073] S20: When the temperature of the hydraulic oil is higher than the second preset temperature value or after the heater 3 starts for a set time, control the oil change control valve 42 to open and start the oil pump 22.

[0074] Among them, the temperature sensor 61 can be used to detect whether the temperature of the hydraulic oil reaches the temperature requirement when the liquid-driven hydrogen compressor 1 operates normally. That is, by obtaining the temperature of the hydraulic oil detected by the temperature sensor 61, when the temperature of the hydraulic oil is higher than the second preset temperature value (the second preset temperature value is greater than the first preset temperature value, and when the temperature of the hydraulic oil is higher than the second preset temperature value, the viscosity of the hydraulic oil is small and the fluidity is large, which can be used to drive the liquid-driven hydrogen compressor 1 to operate normally), the hydraulic oil in the liquid-driven hydrogen compressor 1 is replaced. It is also possible to judge whether the hydraulic oil in the fuel tank 21 reaches the temperature requirement for the normal operation of the liquid-driven hydrogen compressor 1 by the heating duration of the hydraulic oil in the fuel tank 21 by the heater 3, and the heating duration set by the user can be obtained by calculation. That is, according to the amount of the hydraulic oil in the fuel tank 21, the temperature of the hydraulic oil, and the power of the heater 3, the duration required to heat the hydraulic oil to the second preset temperature value can be calculated. The heating duration set by the user can also be obtained according to experience or experimental data.

[0075] S30: After the oil pump 22 works for a preset time, control the oil change control valve 42 to close and start the liquid-driven hydrogen compressor 1. The preset working duration of the oil pump 22 can be obtained according to experience or experimental data, or can be calculated according to the volume of the liquid cavity 111 of the liquid-driven hydrogen compressor 1, the power of the oil pump 22, and the lengths of the first pipeline 241, the second pipeline 242, and the third pipeline 243 between the fuel tank 21 and the liquid-driven hydrogen compressor 1. The heater 3 can be turned off when the temperature of the hydraulic oil is higher than the second preset temperature value, after the liquid-driven hydrogen compressor 1 is started, or after the liquid-driven hydrogen compressor 1 is started for a set duration.

[0076] Through the above method, automatic replacement of the low-temperature hydraulic oil of the liquid-driven hydrogen compressor 1 can be realized, making the operation more convenient.

[0077] In other embodiments, the user can also judge the temperature of the hydraulic oil according to experience and manually perform the oil change work. For example, when the temperature is low and the liquid-driven hydrogen compressor 1 does not work for a long time, the temperature of the hydraulic oil in the fuel tank 21 is usually low, and the user can directly manually operate the oil change work. For example, first start the heater 3, and after the heater 3 starts for a certain time, control the oil change control valve 42 to open and start the oil pump 22; after the oil pump 22 works for a certain time, control the oil change control valve 42 to close, complete the replacement of the low-temperature hydraulic oil in the liquid-driven hydrogen compressor 1, and thus start the liquid-driven hydrogen compressor 1.

[0078] When the liquid-driven hydrogen compressor 1 needs to be cleaned, the user can perform manual oil change. Specifically, connect the end of the oil change pipeline 41 far away from the liquid-driven hydrogen compressor 1 to the waste oil collection tank, then control the oil change control valve 42 to open, and start the oil pump 22. Then, switch the state of the oil inlet control valve 23 to make the hydraulic oil in the fuel tank 21 enter the hydraulic oil in the liquid-driven hydrogen compressor 1, so as to clean the liquid-driven hydrogen compressor 1.

[0079] The cylinder circulation system of the liquid-driven hydrogen compressor of the present application includes a liquid-driven hydrogen compressor 1, a hydraulic drive assembly 2, a heater 3 and an oil change assembly 4. The hydraulic drive assembly 2 is connected to the liquid-driven hydrogen compressor 1 and provides hydraulic oil for the liquid-driven hydrogen compressor 1 to drive the liquid-driven hydrogen compressor 1 to work. The heater 3 is connected to the fuel tank 21 and heats the hydraulic oil. The oil change assembly 4 includes an oil change pipeline 41 and an oil change control valve 42. The oil change pipeline 41 is connected to at least one of the first cavity 1111 and the second cavity 1112 and the fuel tank 21, and the first cavity 1111 or the second cavity 1112 communicated with the oil change pipeline 41 is communicated with the fuel tank 21 through the oil inlet pipeline 24, so that the fuel tank 21, the liquid-driven hydrogen compressor 1 and the oil change pipeline 41 form a circulation loop. The oil change control valve 42 is arranged on the oil change pipeline 41. When the temperature of the hydraulic oil is relatively low, by starting the heater 3 and the oil pump 22 of the hydraulic drive assembly 2, and controlling the oil change control valve 42 to open, the hydraulic oil heated by the heater 3 enters the liquid-driven hydrogen compressor 1 under the action of the oil pump 22, and the hydraulic oil originally in the liquid-driven hydrogen compressor 1 is replaced into the fuel tank 21 through the oil change pipeline 41, so as to realize that the low-temperature hydraulic oil in the liquid-driven hydrogen compressor 1 is replaced by the hydraulic oil at the normal working temperature, so that the hydraulic oil entering the liquid-driven hydrogen compressor 1 when the liquid-driven hydrogen compressor 1 starts is at the normal working temperature, and when replacing the low-temperature hydraulic oil in the liquid-driven hydrogen compressor 1, it is not necessary to start the liquid-driven hydrogen compressor 1, avoiding the problems of difficult start-up of the cylinder circulation system of the liquid-driven hydrogen compressor at low temperature and damage to the equipment.

[0080] Although the present invention has been described with reference to several exemplary embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above-described embodiments are not limited to any of the foregoing details, but should be broadly construed within the spirit and scope defined by the appended claims. Therefore, all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A liquid-driven hydrogen compressor oil cylinder circulation system, characterized in that: include: A liquid-driven hydrogen compressor comprises a cylinder, a driving side piston and a driving rod, wherein the driving side piston is movably arranged in the cylinder and divides the interior of the cylinder into a first cavity and a second cavity, and the driving rod is connected to the driving side piston; A hydraulic drive assembly, comprising an oil tank, an oil pump, an oil inlet control valve and an oil inlet pipeline, wherein the oil inlet pipeline is connected to the oil tank, the first cavity and the second cavity, the oil pump and the oil inlet control valve are both connected to the oil inlet pipeline, and the oil pump is arranged between the oil inlet control valve and the oil tank; the oil inlet control valve is used to control the oil tank to communicate with the first cavity or the second cavity through the oil inlet pipeline; A heater, disposed in the oil tank, for heating the hydraulic oil in the oil tank; An oil change assembly includes an oil change pipeline and an oil change control valve, wherein the oil change pipeline connects at least one of the first cavity and the second cavity and the oil tank, and when the oil inlet pipeline is connected to the first cavity, the oil change pipeline is at least connected to the first cavity; or when the oil inlet pipeline is connected to the second cavity, the oil change pipeline is at least connected to the second cavity; the oil change control valve is arranged on the oil change pipeline to control the on and off of the oil change pipeline.

2. The liquid-driven hydrogen compressor oil cylinder circulation system according to claim 1 is characterized in that: The oil change pipeline is connected to both the first cavity and the second cavity, and the oil change control valve can control the first cavity to be connected to the oil tank and the second cavity to be connected to the oil tank.

3. The liquid-driven hydrogen compressor oil cylinder circulation system according to claim 2 is characterized in that: The oil change pipeline includes a first oil change pipeline and a second oil change pipeline, the first oil change pipeline connects the first cavity and the oil tank, and the second oil change pipeline connects the second cavity and the oil tank; The oil change control valve includes a first oil change control valve and a second oil change control valve. The first oil change control valve is connected in series to the first oil change pipeline to control the on-off of the first oil change pipeline. The second oil change control valve is connected in series to the second oil change pipeline to control the on-off of the second oil change pipeline.

4. The liquid-driven hydrogen compressor oil cylinder circulation system according to claim 3 is characterized in that: The cylinder body is provided with a first oil port, a second oil port, a third oil port and a fourth oil port, the first oil port and the second oil port are arranged at intervals and are both communicated with the first cavity, the third oil port and the fourth oil port are arranged at intervals and are both communicated with the second cavity; The first oil port and the third oil port are connected to the oil inlet pipeline respectively, and the second oil port and the fourth oil port are connected to the oil change pipeline.

5. The liquid-driven hydrogen compressor oil cylinder circulation system according to claim 1, characterized in that: The oil inlet control valve is a reversing valve; the oil inlet control valve comprises a first interface, a second interface, a third interface and a fourth interface; the oil inlet control valve can be switched to a first state in which the first interface is connected to the second interface and the third interface is connected to the fourth interface, or switched to a second state in which the first interface is connected to the third interface and the second interface is connected to the fourth interface; The oil inlet pipeline includes a first pipeline, a second pipeline, a third pipeline and a fourth pipeline, the first pipeline connects the oil tank and the first interface, the second pipeline connects the second interface and the first cavity, the third pipeline connects the third interface and the second cavity, and the fourth pipeline connects the fourth interface and the oil tank; The oil pump is connected in series to the first pipeline.

6. The liquid-driven hydrogen compressor oil cylinder circulation system according to claim 5, characterized in that: The oil inlet control valve can also be switched to a third state in which the first interface, the second interface, the third interface and the fourth interface are not connected to each other; The hydraulic drive assembly further includes an overflow pipeline and an overflow valve. The overflow pipeline is connected to the first pipeline and the oil tank, and the overflow valve is arranged on the overflow pipeline.

7. The liquid-driven hydrogen compressor oil cylinder circulation system according to claim 5, characterized in that: The hydraulic drive assembly further includes a one-way valve and an accumulator, wherein the one-way valve is connected in series to the first pipeline and is located between the oil pump and the oil inlet control valve; The accumulator is connected to the first pipeline and is located between the one-way valve and the oil inlet control valve.

8. The liquid-driven hydrogen compressor oil cylinder circulation system according to claim 4, characterized in that: The hydraulic drive assembly further includes a cooler, and the cooler is disposed on the fourth pipeline or the oil tank.

9. The liquid-driven hydrogen compressor oil cylinder circulation system according to claim 1, characterized in that: The liquid-driven hydrogen compressor cylinder circulation system further includes a temperature sensor, which is disposed in the oil tank and is used to detect the temperature of the hydraulic oil in the oil tank.

10. A method for replacing hydraulic oil using the liquid-driven hydrogen compressor cylinder circulation system as claimed in claim 9, characterized in that: include: Acquiring the temperature of the hydraulic oil detected by the temperature sensor, and when the temperature of the hydraulic oil is lower than a first preset temperature value, the controller starts the heater; When the temperature of the hydraulic oil is higher than a second preset temperature value or the heater is started for a set time, the oil change control valve is controlled to open and the oil pump is started; the second preset temperature value is greater than the first preset temperature value; After the oil pump works for a preset time, the oil change control valve is controlled to close, and the liquid-driven hydrogen compressor is started.

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