Solid hydrogen storage system and overpressure prevention method

Abstract

The solid-state hydrogen storage system comprises a solid-state hydrogen storage tank provided with a rupture disk and a safety valve, and is characterized in that the solid-state hydrogen storage tank is provided with a pressure detection element connected with a control system, and an air inlet and an air outlet of the solid-state hydrogen storage tank are connected with a hydrogen release pipeline and a pressure relief pipeline which are arranged in parallel; a buffer tank is arranged on the pressure relief pipeline, an automatic valve connected with the control system is arranged on the upstream of a gas inlet of the buffer tank, the solid buffer tank is further connected with a cooling circulation system connected with the control system, and the maintenance cost is reduced by adopting the solid hydrogen storage system.

Description

Technical Field

[0001] The present invention relates to the technical field of solid-state hydrogen storage, and in particular to a solid-state hydrogen storage system and an overpressure prevention method. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Hydrogen energy is abundant in sources, green and environmentally friendly, has high energy density, high conversion efficiency, and a wide range of applications. Among all currently known energy sources, it is the cleanest form of energy. Many countries have developed hydrogen energy as a strategic energy source and regard it as the "energy of the future."

[0004] According to the hydrogen storage method, there are three main methods: high-pressure gaseous, liquid, and solid hydrogen storage. Compared with the other two hydrogen storage methods, solid hydrogen storage has the advantages of high hydrogen storage density, safety and reliability. It is currently the most promising hydrogen storage method.

[0005] However, it cannot be ignored that under the condition of long-term storage of solid hydrogen storage alloys, due to changes in ambient temperature, the pressure fluctuation of solid hydrogen storage tanks is much greater than that of gas storage tanks, especially when filled with hydrogen under low-temperature conditions. When the temperature rises, part of the hydrogen will change from atomic hydrogen to molecular hydrogen. The mass hydrogen storage density of hydrogen storage alloys at 10°C and 40°C differs by more than 0.2%. In addition, the design pressure of solid hydrogen storage tanks is generally low, which can easily cause the gas pressure in the tank to exceed the design pressure of the hydrogen storage container and cause safety risks.

[0006] The current solution is to add bursting discs and safety valves to the container, but these are safety facilities that will only be activated under accident conditions. Once activated, the bursting disc will be scrapped and the life of the safety valve will be affected. Subsequent disassembly, replacement or repair and verification are required, which increases maintenance costs. In addition, the large amount of hydrogen emitted will also be wasted. Summary of the invention

[0007] In view of the deficiencies in the prior art, the object of the present invention is to provide a solid-state hydrogen storage system and an overpressure prevention method, which can implement distributed pressure reduction measures, avoid the bursting disc and safety valve being activated only under accident conditions, and reduce maintenance costs.

[0008] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0009] In the first aspect, an embodiment of the present invention provides a solid-state hydrogen storage system, including a solid-state hydrogen storage tank, the solid-state hydrogen storage tank is provided with a bursting disc and a safety valve, the solid-state hydrogen storage tank is provided with a pressure detection element connected to a control system, the air inlet and outlet of the solid-state hydrogen storage tank are connected to a hydrogen discharge pipeline and a pressure relief pipeline arranged in parallel, a buffer tank is provided on the pressure relief pipeline, an automatic valve connected to the control system is provided upstream of the air inlet of the buffer tank, and the solid-state buffer tank is also connected to a cooling circulation system connected to the control system.

[0010] Optionally, the gas inlet and outlet of the solid-state hydrogen storage tank are connected to a hydrogen filling pipeline.

[0011] Optionally, the pressure relief line is connected to a hydrogen discharge line.

[0012] Optionally, the switch valve adopts a pneumatic ball valve connected to a control system.

[0013] Optionally, the automatic valve adopts a pneumatic ball valve connected to a control system.

[0014] Optionally, the cold circulation system includes a cooling pipe connected to the wall of a fixed hydrogen storage tank, the water inlet end of the cooling pipe is connected to a water pump through a water inlet pipeline, the water pump is connected to a water outlet of a refrigeration device, and the return water end of the cooling pipe is connected to a water inlet of the refrigeration device through a return water pipeline.

[0015] Optionally, valves are installed at the water inlet and outlet of the refrigeration device.

[0016] Optionally, the pressure detection element uses a pressure transmitter installed in the solid hydrogen storage tank, and the pressure transmitter is connected to the control system.

[0017] In a second aspect, an embodiment of the present invention provides a method for preventing overpressure of a solid-state hydrogen storage system according to the first aspect:

[0018] The pressure detection element detects the pressure in the solid hydrogen storage tank in real time and transmits it to the control system. When the pressure value reaches the set warning pressure:

[0019] First, a buffer tank is used for pressure relief: the control system controls the automatic valve to open, and the hydrogen in the solid hydrogen storage tank flows into the buffer tank for pressure relief;

[0020] If the pressure in the solid hydrogen storage tank still rises to the warning pressure after the pressure is relieved by the buffer tank, the cooling circulation system is used to reduce the pressure: the control system controls the cooling circulation system to cool down the solid hydrogen storage tank until the pressure in the solid hydrogen storage pipe drops to the set pressure value, and the control system controls the cooling circulation system to stop working;

[0021] If the pressure in the solid hydrogen storage tube still rises to the activation pressure of the safety valve and bursting disc after using the buffer tank and cooling circulation system, the safety valve and bursting disc will be activated to empty the solid hydrogen storage tank.

[0022] Optionally, the warning pressure is lower than the starting pressure of the safety valve and the bursting disc, and the set pressure value is lower than the warning pressure.

[0023] The beneficial effects of the present invention are as follows:

[0024] The solid-state hydrogen storage system and overpressure prevention method of the present invention are provided with a buffer tank and a cooling circulation system. The solid-state hydrogen storage tank is installed with a pressure detection element. When the pressure detection element detects that the pressure in the solid-state hydrogen storage tank reaches a set warning pressure, the automatic valve is first opened to use the buffer tank for pressure relief. If the pressure of the buffer tank still reaches the set warning pressure after the pressure relief, the cooling circulation system is used to reduce the pressure. When the buffer tank and the cooling circulation system are unable to control the pressure increase, the solid-state hydrogen storage tank is emptied by a bursting disc and a safety valve, and finally a safe, economical and convenient step-by-step overpressure protection container safety measure is achieved. Before the bursting disc and the safety valve work, the buffer tank and the cooling circulation system are used to reduce the pressure in steps, rather than waiting until the pressure rises to the starting pressure of the bursting disc and the safety valve and then using the bursting disc and the safety valve for pressure relief. This avoids the scrapping of the bursting disc and the impact on the life of the safety valve and the waste of hydrogen due to overpressure each time, reduces maintenance costs, and has good practical and economic value at large-scale hydrogen storage sites. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0026] Figure 1 It is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0027] Among them, 1. solid hydrogen storage tank, 2. hydrogen discharge pipeline, 3. pressure relief pipeline, 4. buffer tank, 5. bursting disc, 6. safety valve, 7. first pneumatic ball valve, 8. second pneumatic ball valve, 9. hydrogen filling pipeline, 10. pressure transmitter, 11. water inlet pipeline, 12. water pump, 13. return water pipeline, 14. chiller. DETAILED DESCRIPTION

[0028] Example 1

[0029] This embodiment provides a solid-state hydrogen storage system, such as Figure 1As shown, it includes a solid-state hydrogen storage tank 1, and the gas inlet and outlet of the solid-state hydrogen storage tank 1 are connected to a hydrogen discharge pipeline 2 and a pressure relief pipeline 3 arranged in parallel, and the hydrogen discharge pipeline 2 and the pressure relief pipeline 3 are connected in parallel to the total hydrogen discharge pipeline, and a valve is arranged on the total hydrogen discharge pipeline. In this embodiment, a valve is arranged at the gas inlet and outlet of the solid-state hydrogen storage tank 1, and the valve is connected to the hydrogen discharge pipeline 2 and the pressure relief pipeline 3 arranged in parallel, and a buffer tank 4 is arranged on the pressure relief pipeline 3, and an automatic valve connected to the control system is arranged upstream of the buffer tank 4, and the control system can control the opening and closing of the automatic valve. Thereby, the switching of the connection and disconnection states of the solid-state hydrogen storage tank 1 and the buffer tank 4 is realized. When the automatic valve is opened and the buffer tank 4 and the solid-state hydrogen storage tank 1 are connected through the pressure relief pipeline 3, the solid-state hydrogen storage tank 1 can be depressurized. A pressure detection element is installed on the solid-state hydrogen storage tank 1 to detect the hydrogen pressure in the solid-state hydrogen storage tank 1. A bursting disc 5 and a safety valve 6 are also installed on the solid-state hydrogen storage tank 1 to empty the solid-state hydrogen storage tank 1. The structure and setting method of the bursting disc 5 and the safety valve 6 can adopt the existing technology and will not be described in detail here.

[0030] The solid-state hydrogen storage tank 1 is also connected to a cooling circulation system for cooling the solid-state hydrogen storage tank 1 , thereby reducing the gas pressure in the solid-state hydrogen storage tank 1 .

[0031] In this embodiment, the solid-state hydrogen storage tank 1 adopts a 316L stainless steel tank body, which is filled with a set amount of hydrogen storage alloy. The hydrogen storage alloy can be made of existing materials, such as AB2 type or AB5 type or AB type hydrogen storage alloys. Existing materials can be used and will not be described in detail here.

[0032] The gas inlet and outlet of the solid-state hydrogen storage tank 1 are connected to a hydrogen discharge pipeline 2 and a pressure relief pipeline 3 which are arranged in parallel, and hydrogen can be delivered to the hydrogen discharge pipeline 2 and the pressure relief pipeline 3 .

[0033] Along the flow direction of the hydrogen, the pressure relief pipeline 3 is provided with an automatic valve and a buffer tank 4 in sequence.

[0034] In this embodiment, the automatic valve adopts a first pneumatic ball valve 7, and the first pneumatic ball valve 7 is connected to the control system and can receive instructions from the control system to work.

[0035] The buffer tank 4 is a gaseous hydrogen storage tank, which is an auxiliary equipment for hydrogen production by electrolyzer. Its design pressure is the same as that of the solid hydrogen storage tank 1, which is 5.5 MPa. It is used for capacity expansion and pressure reduction in case of overpressure.

[0036] The air inlet end of the pressure relief pipeline 6 is connected to the air inlet and outlet of the solid hydrogen storage tank 1 , and the air outlet end thereof is connected to the hydrogen discharge pipeline 2 , so that the hydrogen in the buffer tank 4 can be delivered to the hydrogen discharge pipeline 2 .

[0037] Along the flow direction of hydrogen, a switch valve is installed on the pressure relief line 3 downstream of the buffer tank 4. Preferably, the switch valve adopts a second pneumatic ball valve 8 connected to the control system.

[0038] The buffer tank 4 can be deflated by opening the second pneumatic ball valve 8 .

[0039] The gas inlet and outlet of the solid-state hydrogen storage tank 1 are also connected to a hydrogen filling pipeline 9 for filling hydrogen into the solid-state hydrogen storage tank 1 .

[0040] The solid-state hydrogen storage tank 1 is provided with a pressure detection element, and the pressure detection element adopts a pressure transmitter 10. The pressure transmitter 10 is connected to the control system and can transmit the collected hydrogen pressure information in the solid-state hydrogen storage tank 1 to the control system.

[0041] The solid-state hydrogen storage tank 1 is connected to a cooling circulation system, and the cooling circulation system is used to cool the solid-state hydrogen storage tank 1, thereby reducing the pressure of the gas in the solid-state hydrogen storage tank.

[0042] The cooling circulation system includes a cooling pipe wound around the wall of the solid hydrogen storage tank, the water inlet end of the cooling pipe is connected to the water pump 12 through the water inlet pipeline 11, the water pump 12 is connected to the water outlet of the refrigeration device through the pipeline, and the return water end of the cooling pipe is directly connected to the water inlet of the refrigeration device through the return water pipeline 13.

[0043] The refrigeration device uses an existing chiller 14, which can be used as existing equipment and will not be described in detail here. It is used to cool the cooling water after heat exchange to ensure its cooling effect.

[0044] Furthermore, valves are provided at the water inlet and the water outlet of the chiller 14 to control the opening and closing of the water inlet and the water outlet.

[0045] The water pump 12 and the chiller 14 are both connected to a control system and can receive instructions from the control system to operate.

[0046] The control system adopts a PLC controller. It is understandable that the control system may also adopt other types of controllers, and those skilled in the art may select the one according to actual needs.

[0047] Example 2

[0048] This embodiment provides a method for preventing overpressure of the solid-state hydrogen storage system described in Embodiment 1:

[0049] The pressure transmitter 10 detects the hydrogen pressure in the solid hydrogen storage tank 1 in real time, and transmits the detected pressure information to the PLC controller.

[0050] When the pressure value reaches the set warning pressure:

[0051] First, a buffer tank is used for pressure relief: the valves at the air inlet and outlet of the solid-state hydrogen storage tank are opened, and the control system controls the first pneumatic ball valve 7 upstream of the buffer tank to open. The hydrogen in the solid-state hydrogen storage tank 1 flows into the buffer tank through the pressure relief pipeline 3 for pressure relief until the pressure value drops below the warning pressure. According to the Claperon equation, when the volume is designed to be 1.2 times the volume of the solid-state storage tank, the solid-state hydrogen storage tank can be reduced to a safe range due to the ambient temperature being ≤45°C.

[0052] In an abnormal environment, for example, when the ambient temperature exceeds 45°C, the hydrogen storage alloy releases a large amount of hydrogen into the solid hydrogen storage tank 2 due to the continuous increase in temperature. If the pressure in the solid hydrogen storage tank 1 still rises to the warning pressure after the pressure is relieved by the buffer tank 4, the cooling circulation system is used to reduce the pressure: the PLC controller controls the cooling circulation system to start the water pump 12 and the chiller 14 to cool the solid hydrogen storage tank 1 until the pressure in the solid hydrogen storage tank 1 drops to the set pressure value, at which time the PLC controller controls the chiller 14 and the water pump 12 to stop working;

[0053] If the buffer tank 4 and the cooling circulation system are used, and if an accident occurs around the solid-state hydrogen storage system, the temperature of the solid-state hydrogen storage tank 1 rises instantly, and the buffer tank 4 and the cooling circulation system can no longer control the temperature rise, the pressure in the solid-state hydrogen storage tank 1 still rises to the starting pressure of the safety valve 6 and the bursting disc 5, and the safety valve 6 and the bursting disc 5 are activated to quickly empty the solid-state hydrogen storage tank 1.

[0054] In this embodiment, the warning pressure is lower than the starting pressure of the safety valve and the bursting disc, and the set pressure value is lower than the warning pressure.

[0055] Preferably, the set warning pressure is 0.9 times the starting pressure of the safety valve and the bursting disc, and the set pressure value is 0.8 times the starting pressure of the safety valve and the bursting disc.

[0056] By adopting the anti-overpressure method of the present embodiment, the buffer tank 4 is first used for pressure relief. If the pressure of the buffer tank 4 still reaches the set warning pressure after the pressure relief, the cooling circulation system is used to reduce the pressure. When the buffer tank 4 and the cooling circulation system are unable to control the pressure increase, the bursting disc 5 and the safety valve 6 are used to empty the solid hydrogen storage tank 1, thereby finally achieving a safe, economical and convenient step-by-step anti-overpressure protection container safety measure. Before the bursting disc 5 and the safety valve 6 work, the buffer tank 4 and the cooling circulation system are used for step-by-step pressure reduction, rather than waiting until the pressure rises to the starting pressure of the bursting disc 5 and the safety valve 6 and then using the bursting disc 5 and the safety valve 6 to relieve the pressure. This avoids the bursting disc 5 being scrapped and the life of the safety valve 6 being affected by each overpressure, as well as the waste of hydrogen, thereby reducing maintenance costs and having good practical and economic value at large-scale hydrogen storage sites.

[0057] In a practical application of this embodiment:

[0058] A DN500 container is used as the solid hydrogen storage tank 1, and the water volume of the tank is 1.8m 3 , 5t hydrogen storage alloy is loaded inside, the hydrogen storage capacity is 80kg, the solid hydrogen storage tank 1 container design pressure is 5.5MPa, the safety valve 6 and bursting disc 5 start pressure is 4.9MPa, the buffer tank 4 is 2m 3 The gas storage tank uses a chiller at 10°C during the hydrogen filling process. After the hydrogen filling is completed, the pressure in the container is 3.2MPa, the temperature of the hydrogen storage alloy is about 25°C, and the external environment is about 35-40°C. When the temperature of the hydrogen storage alloy slowly rises to above 35°C, the buffer tank 4 is depressurized, that is, the pressure in the container increases with the temperature. When the pressure transmitter 10 detects a pressure exceeding the warning pressure of 4.4MPa activated by the safety valve 6 and the bursting disc 5, the PLC controller sends a signal to the first pneumatic ball valve 7, and the solid hydrogen storage tank 1 is connected to the buffer tank 4, and the pressure is quickly balanced to the warning pressure.

[0059] If the abnormal external ambient temperature reaches above 45°C, as the temperature of the hydrogen storage alloy continues to rise, when the internal temperature exceeds 45°C, the pressure of the solid hydrogen storage tank 1 connected to the buffer tank 4 exceeds 4.9MPa. At this time, the PLC sends a signal to the chiller 14 and the water pump 12, the chiller 14 is turned on, the water pump 12 is turned on, and the refrigeration and cooling mode is turned on. When the pressure drops to the set pressure value of 3.92MPa, the PLC controller controls the chiller 14 and the water pump 12 to stop working, completing the pressure reduction protection step.

[0060] If dangerous situations such as fire occur outside, the temperature of solid-state hydrogen storage tank 1 rises rapidly. After the buffer tank 4 and the cooling circulation system are depressurized, the pressure in solid-state hydrogen storage tank 1 continues to rise. After reaching the starting pressure of 4.9MPa safety valve 6 and bursting disc 5, the safety valve 6 and bursting disc 5 are activated, and the gas in solid-state hydrogen storage tank 1 is quickly discharged to achieve the pressure reduction protection measure.

[0061] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A solid-state hydrogen storage system, comprising a solid-state hydrogen storage tank, wherein the solid-state hydrogen storage tank is provided with a bursting disc and a safety valve, characterized in that: The solid-state hydrogen storage tank is provided with a pressure detection element connected to the control system. The air inlet and outlet of the solid-state hydrogen storage tank are connected to the hydrogen discharge pipeline and the pressure relief pipeline arranged in parallel. A buffer tank is provided on the pressure relief pipeline. An automatic valve connected to the control system is provided upstream of the air inlet of the buffer tank. The solid-state buffer tank is also connected to a cooling circulation system connected to the control system.

2. A solid-state hydrogen storage system according to claim 1, characterized in that: The gas inlet and outlet of the solid-state hydrogen storage tank are connected to the hydrogen filling pipeline.

3. A solid-state hydrogen storage system as claimed in claim 1, characterized in that: A switch valve installed on the pressure relief line is provided downstream of the buffer tank.

4. A solid-state hydrogen storage system as claimed in claim 3, characterized in that: The switch valve adopts a pneumatic ball valve connected with a control system.

5. A solid-state hydrogen storage system as claimed in claim 1, characterized in that: The automatic valve adopts a pneumatic ball valve connected with a control system.

6. A solid-state hydrogen storage system as claimed in claim 1, characterized in that: The cold circulation system includes a cooling pipe connected to the wall of a fixed hydrogen storage tank, the water inlet end of the cooling pipe is connected to a water pump through a water inlet pipeline, the water pump is connected to a water outlet of a refrigeration device, and the return water end of the cooling pipe is connected to a water inlet of the refrigeration device through a return water pipeline.

7. A solid-state hydrogen storage system as claimed in claim 6, characterized in that: Valves are installed at the water inlet and the water outlet of the refrigeration device.

8. A solid-state hydrogen storage system as claimed in claim 1, characterized in that: The pressure detection element adopts a pressure transmitter installed in the solid hydrogen storage tank, and the pressure transmitter is connected to the control system.

9. A method for preventing overpressure of a solid-state hydrogen storage system according to any one of claims 1 to 8, characterized in that: The pressure detection element detects the pressure in the solid hydrogen storage tank in real time and transmits it to the control system. When the pressure value reaches the set warning pressure: First, a buffer tank is used for pressure relief: the control system controls the automatic valve to open, and the hydrogen in the solid hydrogen storage tank flows into the buffer tank for pressure relief; If the pressure in the solid hydrogen storage tank still rises to the warning pressure after the pressure is relieved by the buffer tank, the cooling circulation system is used to reduce the pressure: the control system controls the cooling circulation system to cool down the solid hydrogen storage tank until the pressure in the solid hydrogen storage pipe drops to the set pressure value, and the control system controls the cooling circulation system to stop working; If the pressure in the solid hydrogen storage tube still rises to the activation pressure of the safety valve and bursting disc after using the buffer tank and cooling circulation system, the safety valve and bursting disc will be activated to empty the solid hydrogen storage tank.

10. The method for preventing overpressure of a solid-state hydrogen storage system according to claim 9, characterized in that: The warning pressure is lower than the starting pressure of the safety valve and the bursting disc, and the set pressure value is lower than the warning pressure.

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