Hydraulic hydrogen unloading system

Abstract

The invention discloses a hydraulic hydrogen unloading system. Comprising a container and a long-tube trailer bottle group, the container internally comprises a liquid collecting box, a motor pump set, a hydraulic medium filtering system, a control valve set, a safety valve set, a hydrogen unloading filtering system and a nitrogen gas bag. The liquid collecting box is connected with the motor pump set and the hydraulic medium filtering system, the hydraulic medium filtering system is connected with the liquid collecting box, and a safety valve set is connected to the hydraulic medium filtering system in parallel; the safety valve group is connected with the control valve group in parallel; the control valve group is connected with the long tube trailer bottle group; the long pipe trailer bottle group is connected with a hydrogen unloading filtering system in the liquid collecting tank; the liquid collecting box is also connected with a nitrogen gas bag; and the hydrogen discharging and filtering system is connected with an external hydrogen adding machine or a compression storage compressor. Most hydrogen can be pushed out, compared with extraction of a compressor, the amount of hydrogen discharged by each hydrogen long pipe trailer is increased, the effective hydrogen transportation amount of each trailer is increased, and the transportation cost is directly reduced.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen fuel, and specifically relates to a hydraulic hydrogen unloading system. Background Technology

[0002] Hydrogen energy possesses dual attributes as both an energy source and a chemical feedstock. It is a crucial technological pathway to achieving "dual carbon" goals, ensuring national energy security, and developing low-carbon energy. With strong government policy support, the hydrogen fuel cell industry is developing rapidly, and hydrogen refueling stations for hydrogen fuel cell vehicles are under comprehensive construction. Except for refueling stations with on-site hydrogen production capabilities, other refueling stations rely on externally transported hydrogen for their supply.

[0003] Hydrogen supply is primarily achieved through road transport using high-pressure hydrogen tube trailers. Hydrogen refueling stations using these trailers utilize compressors to extract and pressurize the hydrogen from the trailers. The compressed, high-pressure hydrogen is then directly transported to the station's high-pressure hydrogen storage tanks for later use by the refueling machines. The unloading process ends when the pressure inside the trailer drops to a level where the compressor can no longer effectively draw it in (i.e., "residual pressure," typically 5-7 MPa), or when the pressure in the station's storage tanks reaches a set upper limit. Currently, hydrogen refueling stations typically use 20 MPa hydrogen tube trailers to refuel from hydrogen production stations, transporting the hydrogen to the station by road. The station's compressors then directly extract the hydrogen from the trailers. This direct unloading method relies heavily on compressors, which are the main source of cost, energy consumption, and maintenance. Their efficiency directly determines the unloading speed and energy consumption. Due to the performance limitations of the compressor and the presence of residual pressure, the hydrogen unloading rate (amount of hydrogen unloaded / total carrying capacity) is low, typically only around 70%. As hydrogen is unloaded from the hydrogen tube trailer, its internal pressure gradually decreases, causing the unloading speed to gradually slow down; moreover, the compressor inlet pressure fluctuates accordingly, and the high load affects the compressor's lifespan. Summary of the Invention

[0004] To address the above issues, a hydraulic hydrogen unloading system was developed. This system involves injecting pressurized hydraulic fluid into a hydrogen-trailer to push the hydrogen out. The hydraulic pushing speed is faster than compressor extraction; and the hydraulic fluid can push out almost all the hydrogen (over 93%), with low residual pressure, meaning each vehicle can "unload" significantly more hydrogen, directly reducing transportation costs. The pushed-out hydrogen, due to being squeezed out by liquid, has a stable pressure (close to the initial pressure of the trailer) and can be directly supplied to the hydrogen refueling machine for low-pressure refueling, or to the compressor to improve compressor operation. The energy consumption of the hydraulic pump is lower than the energy required for compression to overcome pressure differences, significantly reducing energy consumption.

[0005] The technical solution of this invention is as follows:

[0006] A hydraulic hydrogen unloading system includes a container and a long-tube trailer cylinder assembly. The container contains a collection tank, a motor-pump assembly, a hydraulic medium filtration system, a control valve assembly, a safety valve assembly, a hydrogen unloading filtration system, and a nitrogen bladder. The collection tank is connected to the motor-pump assembly and the hydraulic medium filtration system, which is then connected to the collection tank. A safety valve assembly is connected in parallel to the hydraulic medium filtration system. The safety valve assembly is connected in parallel to the control valve assembly. The control valve assembly is connected to the long-tube trailer cylinder assembly. The long-tube trailer cylinder assembly is connected to the hydrogen unloading filtration system within the collection tank. The collection tank is also connected to the nitrogen bladder. The hydrogen unloading filtration system is connected to an external hydrogen refueling unit or a compressor for compressed storage.

[0007] Furthermore, the liquid collection tank is equipped with a vibration damper, a temperature sensor, a liquid level control relay, a liquid level gauge, a drain port, and a cleaning cover. A butterfly valve is also provided between the vibration damper and the liquid collection tank body.

[0008] Furthermore, the hydraulic medium filtration system is equipped with a pressure line filter and a return fluid filter.

[0009] Furthermore, the motor-pump assembly consists of a shock-absorbing pad, a motor, a bell coupling, and a plunger pump; the motor is located above the shock-absorbing pad, and the motor is sequentially connected to the bell coupling and the plunger pump; the motor drives the plunger pump to draw hydraulic medium from the collection tank and pressurize it for output, realizing the efficient conversion of electrical energy to mechanical energy to liquid pressure energy, and providing power to the system.

[0010] Furthermore, the safety valve assembly is equipped with a pressure gauge for direct observation of system pressure and a three-stage safety protection device; the pressure gauge is connected to the three-stage safety protection device; the three-stage safety protection device consists of an overflow valve, an electro-hydraulic directional valve, and a throttle valve; the throttle valve, overflow valve, and electro-hydraulic directional valve are connected in parallel. A pressure gauge switch is provided between the pressure gauge and the three-stage safety protection device; the electro-hydraulic directional valve is a two-position, two-way electro-hydraulic directional valve.

[0011] Furthermore, the nitrogen gasbag is provided with a hydrogen vent and a nitrogen vent, the hydrogen vent being provided with an exhaust valve and a hydrogen concentration sensor; and the nitrogen vent being provided with a manual ball valve.

[0012] Furthermore, the control valve assembly has the same number of pipelines as the long-tube trailer bottle assembly. These pipelines are connected via electro-hydraulic directional valves, and then via three-position four-way electro-hydraulic directional valves to the pressure pipeline filter and the return filter, respectively. The pipelines are equipped with pressure testing connectors, temperature sensors, flow meters, and pressure sensors. A check valve connects the control valve assembly to the pressure pipeline filter; a throttle valve connects the control valve assembly to the return filter.

[0013] Compared with the existing direct hydrogen unloading method using compressors, the hydraulic hydrogen unloading system, which uses an electric motor to drive a plunger pump to draw hydraulic medium and pressurize it to inject it into a long-tube hydrogen cylinder assembly to push out the hydrogen, has the following advantages:

[0014] 1. Hydrogen is pushed out by hydraulic medium, and its speed depends on the system flow rate. The system flow rate can be changed by selecting different specifications of motor power and plunger pump displacement, that is, the hydrogen unloading speed is selectable and faster than that extracted by compressor.

[0015] 2. The amount of hydrogen that can be discharged from the hydrogen tube trailer cylinder group after being injected with pressurized hydraulic medium is the same as the amount of hydrogen that can be discharged. Most of the hydrogen can be discharged (more than 93%; a small amount of hydrogen remains in the cylinder group to ensure liquid return and to avoid unloading the hydraulic medium as well). Compared with compressor extraction, the amount of hydrogen that can be discharged from each hydrogen tube trailer is increased, and the effective amount of hydrogen transported per vehicle is increased, which directly reduces transportation costs.

[0016] 3. The pressurized hydraulic medium pushes out hydrogen, which is stabilized at around 20MPa. It can first supply hydrogen to the hydrogen dispenser to add hydrogen to 20MPa, and then supply it to the compressor to pressurize it to the required pressure. The compressor no longer needs to "draw" hydrogen from the changing low pressure, but only needs to pressurize this stable gas source. This greatly improves the operating conditions of the compressor, extends its service life, reduces the failure rate and maintenance costs. Moreover, the energy consumption of the hydraulic pump is much lower than the energy consumption required for the compressor to overcome the pressure difference, which can significantly reduce energy consumption. Attached Figure Description

[0017] Figure 1 This is a structural diagram of the present invention;

[0018] Figure 2 This is a schematic diagram of the liquid collection tank.

[0019] Figure 3 This is a schematic diagram of the structure of the motor pump unit;

[0020] Figure 4 This is a schematic diagram of the structure of a safety valve assembly;

[0021] Figure 5 This is a schematic diagram of the control valve assembly.

[0022] Figure 6 This is a schematic diagram of the structure of a nitrogen gasbag.

[0023] The components shown in the diagram are as follows: 1. Collection tank; 2. Motor pump assembly; 3. Hydraulic medium filtration system; 4. Electrical control system; 5. Control valve assembly; 6. Safety valve assembly; 7. First hydrogen long-tube trailer cylinder assembly; 8. Second hydrogen long-tube trailer cylinder assembly; 9. Hydrogen unloading filtration system; 10. Nitrogen gasbag; 11.1 Pressure line filter; 11.2 Return liquid filter; 12. Vibration damper; 13. Butterfly valve; 14. Temperature sensor; 15. Liquid level control relay; 16. Liquid level gauge; 17. Drain port; 18. Cleaning cover. 19. Vibration damping pad; 20. Electric motor; 21. Bell coupling; 22. Piston pump; 23. Pressure test connector; 24. Temperature sensor; 25. Flow meter; 26. Pressure sensor; 27. First two-position two-way electro-hydraulic directional valve; 28. Three-position four-way electro-hydraulic directional valve; 29. ​​Check valve; 30. Throttle valve; 31. Pressure gauge; 32. Pressure gauge switch; 33. Throttle valve; 34. Overflow valve; 35. Second two-position two-way electro-hydraulic directional valve; 36. Exhaust valve; 37. Hydrogen concentration sensor; 38. Manual ball valve. Detailed Implementation

[0024] The following detailed description of specific implementation methods of the present invention, in conjunction with the accompanying drawings, will enable those skilled in the art to more clearly understand how to practice the present invention. Although the present invention has been described in conjunction with preferred specific embodiments, these embodiments are merely brief descriptions and are not intended to limit the scope of the present invention.

[0025] like Figure 1 As shown, this embodiment of a hydraulic hydrogen unloading system includes a container and a long-tube trailer cylinder assembly. The container contains a collection tank 1, a motor pump assembly 2, a hydraulic medium filtration system 3, an electrical control system 4, a control valve assembly 5, a safety valve assembly 6, a hydrogen unloading filtration system 9, and a nitrogen bladder 10. The collection tank 1 is connected to the motor pump assembly 2 and the hydraulic medium filtration system 3. The hydraulic medium filtration system 3 is then connected to the collection tank 1. The safety valve assembly 6 is connected in parallel to the hydraulic medium filtration system 3. The safety valve assembly 6 is connected in parallel to the control valve assembly 5. The control valve assembly 5 is connected to the long-tube trailer cylinder assembly. The long-tube trailer cylinder assembly is connected to the hydrogen unloading filtration system 9 inside the collection tank 1. The collection tank 1 is also connected to the nitrogen bladder 10. In this embodiment, the hydraulic medium filtration system 3 is equipped with high-precision filtration devices such as a pressure pipeline filter 11.1 and a return fluid filter 11.2 to remove solid contaminants from the hydraulic medium output from the motor pump group 2 and the hydraulic medium returned from the first hydrogen long-tube trailer cylinder group 7 and the second hydrogen long-tube trailer cylinder group 8. This keeps the working medium clean, extends the service life of components, and ensures the reliable performance of hydraulic components. In this embodiment, the electrical control system 4 uses a PLC to control the operation of the entire hydraulic hydrogen unloading system.

[0026] The hydrogen storage tank group of the hydrogen long-tube trailer is divided into two groups: the first hydrogen long-tube trailer tank group 7 and the second hydrogen long-tube trailer tank group 8. They are roughly divided in half (e.g., in a 6-tank trailer, the first hydrogen long-tube trailer tank group has 3 tanks and the second hydrogen long-tube trailer tank group has 3 tanks; in a 7-tank trailer, the first hydrogen long-tube trailer tank group has 4 tanks and the second hydrogen long-tube trailer tank group has 3 tanks; in a 9-tank trailer, the first hydrogen long-tube trailer tank group has 5 tanks and the second hydrogen long-tube trailer tank group has 4 tanks). The trailer is equipped with a lifting device and pneumatic valves for the front and rear compartments. The inlet and outlet ports of the hydrogen storage tank group use quick-connect couplings.

[0027] The liquid collection tank 1 is a comprehensive container consisting of a liquid collection tank body, a level gauge 16, a cleaning cover 18, hydraulic accessories such as sensors, and various interfaces. It integrates liquid storage, heat dissipation, sedimentation of impurities, and component installation. Specifically, as shown... Figure 2 As shown, the liquid collection tank is equipped with a vibration damper 12, a temperature sensor 14, a liquid level control relay 15, a liquid level gauge 16, a drain port 17, and a cleaning cover 18. A butterfly valve 13 is also provided between the vibration damper 12 and the liquid collection tank body.

[0028] The motor-pump unit 2 consists of a motor, a plunger pump, a bell-shaped coupling, vibration damping pads, and other mounting and connecting components. For example... Figure 3 As shown, the motor-pump assembly 2 consists of a shock-absorbing pad 19, a motor 20, a bell coupling 21, and a plunger pump 22. The motor 20 is located above the shock-absorbing pad 19, and is sequentially connected to the bell coupling 21 and the plunger pump 22. The motor drives the plunger pump 22 to draw hydraulic medium from the collection tank 1 and pressurize it for output, achieving efficient conversion of electrical energy to mechanical energy to liquid pressure energy, thus providing power to the system.

[0029] The control valve assembly 5 controls the flow direction of the hydraulic medium through a check valve, an electro-hydraulic directional valve, and pressure, flow, and temperature sensors. It adjusts the direction of hydraulic medium entering and exiting the collection tank 1, the first hydrogen long-tube trailer cylinder assembly 7, and the second hydrogen long-tube trailer cylinder assembly 8, ensuring that no hydraulic medium is discharged from the hydrogen outlets of the first hydrogen long-tube trailer cylinder assembly 7 and the second hydrogen long-tube trailer cylinder assembly 8, and that the hydraulic medium is completely discharged during cylinder return. Figure 5 As shown, in this embodiment, the control valve group 5 has the same number of pipelines as the long-tube trailer bottle group. The pipelines are connected by electro-hydraulic directional valves, and then connected to the pressure pipeline filter 11.1 and the return filter 11.2 by three-position four-way electro-hydraulic directional valves respectively. The pipelines are equipped with a pressure testing connector 23, a temperature sensor 24, a flow meter 25, and a pressure sensor 26. A one-way valve 29 is connected to the pipeline between the control valve group 5 and the pressure pipeline filter 11.1. A throttle valve 30 is connected to the pipeline between the control valve group 5 and the return filter 11.2.

[0030] like Figure 4As shown, the safety valve assembly 6 is equipped with a pressure gauge 31 for direct observation of system pressure and a three-stage safety protection device; the pressure gauge 31 is connected to the three-stage safety protection device; the three-stage safety protection device consists of an overflow valve 34, a second two-position two-way electro-hydraulic directional valve 35, and a throttle valve 33; the throttle valve 33, the overflow valve 34, and the electro-hydraulic directional valve are connected in parallel. A pressure gauge switch 32 is provided between the pressure gauge 31 and the three-stage safety protection device.

[0031] In case of an unexpected situation, the overflow valve 34 can release the hydraulic medium exceeding the set pressure back to the collection tank 1. Alternatively, the electrical control system 4 can control the electro-hydraulic directional valve to open, allowing all the hydraulic medium in the system to flow back to the collection tank 1. Or, the manual regulating valve 33 can be used to release all the hydraulic medium in the system back to the collection tank 1, ensuring the safety of the entire hydraulic hydrogen unloading system.

[0032] The hydrogen unloading filtration system 9 is equipped with a multi-stage purification device to remove hydraulic medium that may be mixed in the first hydrogen long-tube trailer cylinder group 7 and the second hydrogen long-tube trailer cylinder group 8, so as to ensure the purity of the hydrogen delivered to the compressor.

[0033] Nitrogen gas bladder 10 is connected to liquid collection tank 1, as follows: Figure 6 As shown, the nitrogen gas bladder 10 is equipped with a hydrogen vent and a nitrogen vent. The hydrogen vent is equipped with an exhaust valve 36 and a hydrogen concentration sensor 37; the nitrogen vent is equipped with a manual ball valve 38. Its working principle is as follows: opening the manual ball valve fills the upper space of the nitrogen gas bladder 10 and the liquid collection tank 1 with nitrogen, isolating the liquid collection tank from the atmosphere and preventing dust in the air from contaminating the hydraulic medium and hydrogen. When a small amount of hydrogen enters the upper part of the liquid storage tank along with the hydraulic medium, it is in a mixed state of nitrogen and hydrogen, isolating oxygen and preventing deflagration. This is detected by the hydrogen concentration sensor. When the hydrogen concentration reaches a set value, the electrically controlled exhaust valve is opened to release the hydrogen.

[0034] After the hydrogen long-tube trailer's liquid and gas ports are connected to the hydraulic hydrogen unloading system hoses using quick-connect couplings (specifically, the hydrogen long-tube trailer's liquid port connects to control valve assembly 5, and the hydrogen long-tube trailer's gas port connects to the hydrogen unloading filter system 9), hydrogen can be unloaded and supplied to the hydrogen dispenser for low-pressure refueling, or to the compressor for compression and storage. The workflow is as follows:

[0035] Start the motor pump unit 2 to draw hydraulic medium from the collection tank 1 and pressurize it to 20MPa for output. After being filtered by the hydraulic medium filtration system 3, it flows in parallel to the safety valve group 6 (under normal working conditions, the safety valve group is not open; under abnormal conditions, the safety valve group opens, and the hydraulic medium flows back to the collection tank) and the control valve group 5. After the direction is adjusted by the three-position four-way electro-hydraulic directional valve 28 in the control valve group 5 (specifically, the three-position four-way electro-hydraulic directional valve 28 is switched from the middle position to the left position, at which time the liquid outlet line of the control valve group 5 is connected to the first hydrogen long tube trailer cylinder group 7, and the liquid return line of the control valve group 5 is connected to the second hydrogen long tube trailer cylinder group 8), the hydraulic medium is injected into the first cylinder of the first hydrogen long tube trailer cylinder group 7 through the liquid outlet line, and the hydrogen is pushed out at a stable pressure of about 20MPa. After being purified by the hydrogen unloading filtration system 9, it is supplied to the hydrogen dispenser for low-pressure filling or to the compressor for compression and storage.

[0036] After the hydraulic medium fills the first cylinder of the first hydrogen long-tube trailer cylinder group 7 to about 93%~95%, the three-position four-way electro-hydraulic directional valve 28 in the control valve group 5 switches direction (specifically, the three-position four-way electro-hydraulic directional valve 28 switches from the left position to the right position. At this time, the outlet line of the control valve group 5 is connected to the second hydrogen long-tube trailer cylinder group 8, and the return line of the control valve group 5 is connected to the first hydrogen long-tube trailer cylinder group 7). The hydraulic medium is injected into the first cylinder of the second hydrogen long-tube trailer cylinder group 8 to push out hydrogen. At the same time, the hydraulic medium in the first cylinder of the first hydrogen long-tube trailer cylinder group 7, under the action of the residual hydrogen pressure in the cylinder and its own gravity, flows to the hydraulic medium filtration system 3 through the return line of the control valve group 5, and after filtration, flows back to the collection tank 1.

[0037] Similarly, when the hydraulic medium fills the first cylinder of the second hydrogen long tube trailer cylinder group 8 to about 93%~95%, the control valve group 5 switches the direction and injects the hydraulic medium into the second cylinder of the first hydrogen long tube trailer cylinder group 7 to release the hydrogen. At the same time, the hydraulic medium in the first cylinder of the second hydrogen long tube trailer cylinder group 8 is filtered by the hydraulic medium filtration system 3 and then flows back to the collection tank 1.

[0038] The process is repeated, with the hydraulic medium switching back and forth between the first and second cylinder groups, operating continuously until the hydrogen is unloaded from the entire hydrogen tube trailer.

[0039] It should be understood that the above detailed description of the technical solutions of the present invention with reference to optimized embodiments is illustrative and not restrictive. It should not be considered that the specific implementation of the present invention is limited to this. For those skilled in the art, any modifications to the technical solutions described in the embodiments or equivalent substitutions of some technical features without departing from the concept of the present invention should be considered as falling within the scope of patent protection defined by the claims submitted by the present invention.

Claims

1. A hydraulic hydrogen unloading system, characterized in that, It includes a container and a long-tube trailer cylinder assembly; the container interior includes a collection tank (1), an electric pump assembly (2), a hydraulic medium filtration system (3), a control valve assembly (5), a safety valve assembly (6), a hydrogen unloading filtration system (9), and a nitrogen gasbag (10). The collection tank (1) is connected to the motor pump group (2) and the hydraulic medium filtration system (3). The hydraulic medium filtration system (3) is then connected to the collection tank (1). A safety valve group (6) is connected in parallel on the hydraulic medium filtration system (3). The safety valve group (6) is connected in parallel with the control valve group (5). The control valve group (5) is connected to the long-tube trailer bottle group. The long-tube trailer bottle group is connected to the hydrogen unloading filtration system (9) inside the collection tank (1). The collection tank (1) is also connected to the nitrogen gas bag (10). The hydrogen unloading filtration system (9) is connected to an external hydrogen refueling machine or a compressor for compressed storage.

2. The hydraulic hydrogen unloading system as described in claim 1, characterized in that, The liquid collection tank (1) is equipped with a shock absorber (12), a temperature sensor (14), a liquid level control relay (15), a liquid level gauge (16), a drain port (17), and a cleaning cover (18). A butterfly valve (13) is also provided between the shock absorber (12) and the liquid collection tank body.

3. The hydraulic hydrogen unloading system as described in claim 1, characterized in that, The hydraulic medium filtration system (3) is equipped with a pressure pipeline filter (11.1) and a return fluid filter (11.2).

4. The hydraulic hydrogen unloading system as described in claim 1, characterized in that, The motor pump unit (2) consists of a shock-absorbing pad (19), a motor (20), a bell coupling (21), and a plunger pump (22). The motor (20) is located above the shock-absorbing pad (19), and the motor (20) is connected in sequence to the bell coupling (21) and the plunger pump (22). The motor (20) drives the plunger pump (22) to extract hydraulic medium from the liquid collection tank (1) and pressurize it for output, thereby realizing the efficient conversion of electrical energy to mechanical energy to liquid pressure energy and providing power for the system.

5. The hydraulic hydrogen unloading system as described in claim 1, characterized in that, The safety valve assembly (6) is equipped with a pressure gauge (31) that allows direct observation of the system pressure and a three-level safety protection device; the pressure gauge (31) is connected to the three-level safety protection device; the three-level safety protection device is composed of an overflow valve (34), an electro-hydraulic directional valve, and a throttle valve (33); the throttle valve (33), the overflow valve (34), and the electro-hydraulic directional valve are connected in parallel.

6. The hydraulic hydrogen unloading system as described in claim 5, characterized in that, A pressure gauge switch (32) is provided between the pressure gauge (31) and the three-level safety protection device; the electro-hydraulic directional valve is a two-position two-way electro-hydraulic directional valve.

7. The hydraulic hydrogen unloading system as described in claim 1, characterized in that, The nitrogen gas bag (10) is provided with a hydrogen discharge port and a nitrogen discharge port. The hydrogen discharge port is provided with an exhaust valve (36) and a hydrogen concentration sensor (37); the nitrogen discharge port is provided with a manual ball valve (38).

8. The hydraulic hydrogen unloading system as described in claim 1, characterized in that, The control valve group (5) is equipped with the same number of pipelines as the long-tube trailer bottle group. The pipeline is connected by an electro-hydraulic directional valve and then connected to the pressure pipeline filter (11.1) and the return filter (11.2) by a three-position four-way electro-hydraulic directional valve. The pipeline is equipped with a pressure test connector (23), a temperature sensor (24), a flow meter (25), and a pressure sensor (26).

9. The hydraulic hydrogen unloading system as described in claim 8, characterized in that, A check valve (29) is connected between the control valve assembly (5) and the pressure line filter (11.1); a throttle valve (30) is connected between the control valve assembly (5) and the return filter (11.2).

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