One-pump-multiple-gun liquid hydrogen filling control system and method

Abstract

The present invention relates to the field of liquid hydrogen filling, in particular to a one-pump-multiple-gun liquid hydrogen filling control system and method, comprising a liquid hydrogen storage tank, a submersible pump, a hydrogenator, a liquid return pipeline and a controller; the liquid hydrogen storage tank is used to store liquid hydrogen, and a first pressure monitoring device is provided on the liquid hydrogen storage tank; the submersible pump is connected to the liquid hydrogen storage tank through a pipeline; a plurality of hydrogenators are connected to the submersible pump through a liquid inlet pipeline; a plurality of hydrogenators are connected to the liquid hydrogen storage tank through a liquid return pipeline, a back pressure device for controlling the opening and closing degree of the pipeline is provided on the liquid return pipeline, and a second pressure monitoring device is provided on the liquid return pipeline between the back pressure device and the hydrogenator; the first pressure monitoring device, the second pressure monitoring device, the hydrogenator and the back pressure device are all electrically connected to the controller. The advantage of the present invention is that the controller obtains the pressure data monitored by the first pressure monitoring device and the second pressure monitoring device, controls the opening and closing degree of the back pressure device, and avoids the filling gun being filled from losing pressure and shutting down in a one-pump-multiple-gun scenario.

Description

Technical Field

[0001] The present invention relates to the field of liquid hydrogen filling, and in particular to a one-pump-multiple-gun liquid hydrogen filling control system and method. Background Art

[0002] Hydrogen is a readily available, green, low-carbon, and widely applicable secondary energy source. my country, with its robust hydrogen production infrastructure and large-scale market, offers significant advantages in developing hydrogen energy. Compared to gaseous hydrogen, liquid hydrogen offers advantages such as high efficiency, controllability, low pollution levels, and consistent quality, making it a key driver of the large-scale deployment of fuel cell vehicles.

[0003] During the liquid hydrogen refueling process, the relevant refueling pipelines need to be pre-cooled before refueling. Currently, this is generally done by utilizing the cold energy of liquid hydrogen itself. That is, liquid hydrogen enters the refueling pipelines through a submersible pump and finally returns to the liquid hydrogen storage tank through the pipelines. In a refueling system with multiple guns using a single pump, if one refueling gun is refueling and another is preparing to refuel and begins pre-cooling, the refueling pipelines will be connected to the liquid hydrogen storage tank at the same time as pre-cooling begins, causing the pressure in the refueling pipeline to drop instantly, further causing the refueling gun to shut down. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a one-pump-multiple-gun liquid hydrogen filling control system and method. This prevents the situation in which one pump-multiple-gun usage scenario where some filling guns are filling while another filling gun begins precooling, causing the filling guns in the filling state to stop.

[0005] The purpose of the present invention is achieved through the following technical solutions: a one-pump, multi-gun liquid hydrogen filling control system, comprising a liquid hydrogen storage tank, a submersible pump, a hydrogenator return liquid pipeline, and a controller. The liquid hydrogen storage tank is used to store liquid hydrogen, and the liquid hydrogen storage tank is provided with a first pressure monitoring device; the submersible pump is connected to the liquid hydrogen storage tank via a pipeline; a plurality of hydrogenators are connected to the submersible pump via a liquid inlet pipeline; a plurality of hydrogenators are connected to the liquid hydrogen storage tank via the return liquid pipeline, a back pressure device for controlling the opening and closing degree of the pipeline is provided on the return liquid pipeline, and a second pressure monitoring device is provided on the return liquid pipeline between the back pressure device and the hydrogenator; the first pressure monitoring device, the second pressure monitoring device, the hydrogenator, and the back pressure device are all electrically connected to the controller, and the controller is used to control the opening and closing degree of the back pressure device.

[0006] The present invention provides a back pressure device to maintain a certain pressure in the filling pipeline when one filling gun is filling and the other filling gun starts to precool, thereby avoiding instant shutdown of the filling gun being filled.

[0007] In some embodiments, the hydrogenator includes a filling gun, a first on-off valve, and a second on-off valve. The liquid inlet pipeline is connected to the filling gun and the liquid return pipeline, respectively. The first on-off valve is disposed between the liquid inlet pipeline and the filling gun, and the second on-off valve is disposed between the liquid inlet pipeline and the liquid return pipeline. The first on-off valve controls the on-off connection between the liquid inlet pipeline and the filling gun, and the second on-off valve controls the on-off connection between the liquid inlet pipeline and the liquid return pipeline.

[0008] In some embodiments, the first on-off valve and the second on-off valve both comprise pneumatic valves. Pneumatic valves improve the overall safety of the hydrogenation machine.

[0009] In some embodiments, the first pressure monitoring device and the second pressure monitoring device both include a pressure transmitter, which converts a pressure signal into an electrical signal and transmits it to a controller.

[0010] In some embodiments, the back pressure device includes a proportional valve, which can accurately control the opening and closing degree of the pipeline, thereby facilitating control of the pipeline pressure.

[0011] In some embodiments, the controller includes an MCU or a PLC. The controller controls the entire system by calculating an input electrical signal and then outputting an electrical signal.

[0012] In some embodiments, the first pressure monitoring device and the second pressure monitoring device are respectively connected to a pressure display device, which is a pressure gauge, so that workers can check the pressure in the pipeline on site.

[0013] In some embodiments, a safety valve is provided between the back pressure device and the liquid hydrogen storage tank on the liquid return line to prevent accidents.

[0014] The present invention also provides a one-pump-multiple-gun liquid hydrogen filling control method, which utilizes the above-mentioned one-pump-multiple-gun liquid hydrogen filling control system, including the following steps:

[0015] Preset target pressure difference Pm before and after the back pressure device;

[0016] Acquire the working state of the hydrogenator, the pressure data P1 of the first pressure monitoring device, and the pressure data P2 of the second pressure monitoring device;

[0017] Calculate the actual pressure difference before and after the back pressure device Pm'=P2-P1;

[0018] According to whether the hydrogen refueling machine is in the filling state, pre-cooling state or unused state, the opening and closing degree of the back pressure device is adjusted as follows:

[0019] If one hydrogenation machine is in the filling state and the other is in the pre-cooling state, the back pressure device is controlled to open or close to control P2 so that Pm = Pm';

[0020] If all hydrogen refueling machines are not in the refueling state, control the back pressure device to be fully open.

[0021] In the present invention, the difference between the actual pressure difference before and after the back pressure device and the target pressure difference is subjected to PID calculation to control the opening and closing degree of the back pressure device, so that the actual pressure difference quickly reaches the target pressure difference and stabilizes.

[0022] In some embodiments, when the hydrogenator is in the filling state, the controller controls the hydrogenator in the filling state to disconnect the return liquid pipeline from the liquid inlet pipeline; when the hydrogenator is in the pre-cooling state, the controller controls the hydrogenator in the pre-cooling state to connect the return liquid pipeline with the liquid inlet pipeline.

[0023] The present invention has the following advantages:

[0024] Using the back pressure device, when one hydrogenation machine is filling and another hydrogenation machine is preparing to fill and start pre-cooling, the opening and closing degree of the return liquid pipeline is controlled so that the return liquid pipeline is partially opened, thereby maintaining a certain pressure difference before and after the back pressure device, avoiding the hydrogenation machine being filled from losing pressure and shutting down instantly.

[0025] In addition, when there is no hydrogen refueling machine filling liquid hydrogen, when the first hydrogen refueling machine starts pre-cooling, the back pressure device can be controlled to be fully open to allow the liquid hydrogen to circulate quickly and be pre-cooled quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a structural diagram of the one-pump-multiple-gun liquid hydrogen filling control system of the present invention;

[0027] Figure 2 This is a schematic diagram of the one-pump-multiple-gun liquid hydrogen filling control system of the present invention;

[0028] Figure 3 This is a control flow chart of the one-pump-multiple-gun liquid hydrogen filling control method of the present invention;

[0029] In the figure: 1. Liquid hydrogen storage tank; 2. Submersible pump; 3. Liquid inlet pipeline; 4. Hydrogenator; 41. First on-off valve; 42. Second on-off valve; 5. Liquid return pipeline; 6. Back pressure device; 7. First pressure monitoring device; 8. Second pressure monitoring device; 9. Pressure display device; 10. Safety valve. DETAILED DESCRIPTION

[0030] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for the purpose of explaining the present invention and are not intended to limit the present invention. That is, the embodiments described herein are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and illustrated in the drawings herein can be arranged and designed in various different configurations.

[0031] The present invention will be further described below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following description.

[0032] like Figure 1-2 As shown, a one-pump-multiple-gun liquid hydrogen filling control system comprises a liquid hydrogen storage tank 1, a submersible pump 2, a hydrogenator 4, a liquid return pipeline 5 and a controller; the liquid hydrogen storage tank 1 is used to store liquid hydrogen, and the liquid hydrogen storage tank 1 is provided with a first pressure monitoring device 7; the submersible pump 2 is connected to the liquid hydrogen storage tank 1 through a pipeline; multiple hydrogenators 4 are connected to the submersible pump 2 through a liquid inlet pipeline 3; multiple hydrogenators 4 are connected to the liquid hydrogen storage tank 1 through the liquid return pipeline 5, and the liquid return pipeline 5 is provided with a back pressure device 6 for controlling the opening and closing degree of the pipeline, and a second pressure monitoring device 8 is provided on the liquid return pipeline 5 between the back pressure device 6 and the hydrogenator 4; the first pressure monitoring device 7, the second pressure monitoring device 8, the hydrogenator 4 and the back pressure device 6 are all electrically connected to the controller, and the controller is used to control the opening and closing degree of the back pressure device 6.

[0033] In this embodiment, specifically, several hydrogenators 4 are supplied with liquid hydrogen through a submersible pump 2. During filling, multiple liquid inlet pipelines 3 are connected and the pressure is equal. The liquid return pipeline 5 is provided with a main pipe and multiple branch pipes. A back pressure device 6 is provided on the main pipe. Several hydrogenators 4 are respectively connected to the main pipe through multiple branch pipes, and are connected to the liquid hydrogen storage tank 1 through the main pipe. When the hydrogenator 4 is in the filling state, the liquid inlet pipeline 3 is disconnected from the liquid return pipeline 5, and the liquid inlet pipeline 3 is connected to the filled container; when the hydrogenator 4 is in the pre-cooling state, the liquid inlet pipeline 3 is directly connected to the liquid return pipeline 5, and the liquid hydrogen in the liquid inlet pipeline 3 is directly returned to the liquid hydrogen storage tank 1 through the liquid return pipeline 5, thereby pre-cooling the pipelines in the hydrogenator 4.

[0034] Preferably, the hydrogenator 4 includes a filling gun, a first on-off valve 41 and a second on-off valve 42, the liquid inlet pipeline 3 is respectively connected to the filling gun and the liquid return pipeline 5, the first on-off valve 41 is provided between the liquid inlet pipeline 3 and the filling gun, and the second on-off valve 42 is provided between the liquid inlet pipeline 3 and the liquid return pipeline 5. In this embodiment, specifically, the filling gun is communicated with the controller via an RS485 module, and the controller determines whether the hydrogenator 4 is in a filling state. When the hydrogenator 4 is in a filling state, the first on-off valve 41 is opened and the second on-off valve 42 is closed; when the hydrogenator 4 is in a pre-cooling state, the first on-off valve 41 is closed and the second on-off valve 42 is opened, so that the liquid inlet pipeline 3 is connected to the liquid return pipeline 5.

[0035] Preferably, the first on-off valve 41 and the second on-off valve 42 both comprise pneumatic valves. Pneumatic valves have high safety. Pneumatic valves are provided in the hydrogenator 4 to improve the overall safety of the system.

[0036] Preferably, the first pressure monitoring device 7 and the second pressure monitoring device 8 both include a pressure transmitter, which is convenient for converting the pressure signal into an electrical signal and transmitting it to the controller.

[0037] Preferably, the back pressure device 6 includes a proportional valve. Through the proportional valve, the proportional valve can accurately control the opening and closing of the liquid return pipeline 5, so as to achieve the purpose of accurately controlling the pressure difference before and after the back pressure device 6.

[0038] Preferably, the controller includes an MCU or a PLC.

[0039] Preferably, the first pressure monitoring device 7 and the second pressure monitoring device 8 are respectively connected to a pressure display device 9. In this embodiment, the pressure display device 9 is a pressure gauge, which allows operators to directly check the pressure in the pipeline on site.

[0040] Preferably, a safety valve 10 is provided between the back pressure device 6 on the liquid return line 5 and the liquid hydrogen storage tank 1. When the pressure in the liquid hydrogen storage tank 1 is too high, the safety valve 10 opens to release the pressure, thereby improving the safety of the entire system.

[0041] like Figure 3 As shown, the present invention also provides a one-pump-multiple-gun liquid hydrogen filling control method. Based on the above system, the specific steps include:

[0042] Step 1: preset the target pressure difference Pm before and after the back pressure device 6;

[0043] Step 2: Obtain the working state of the hydrogenator 4, the pressure data P1 of the first pressure monitoring device 7 and the pressure data P2 of the second pressure monitoring device 8. In this embodiment, the working state of the hydrogenator 4 includes the filling state, the pre-cooling state and the unused state.

[0044] Step 3: Calculate the actual pressure difference before and after the back pressure device 6, Pm'=P2-P1;

[0045] Step 4: According to whether the hydrogenator 4 is in a filling state, a pre-cooling state, or an unused state, the opening and closing degree of the back pressure device 6 is adjusted as follows:

[0046] If one hydrogenator 4 is in the filling state and the other is in the pre-cooling state, the back pressure device 6 is controlled to open or close to control P2 so that Pm=Pm';

[0047] If all hydrogen refueling machines 4 are not in the refueling state, the back pressure device 6 is controlled to be fully opened.

[0048] In this embodiment, the situation where all hydrogenators 4 are not in the filling state includes: all hydrogenators 4 are in the unused state; some hydrogenators 4 are in the pre-cooling state, and some hydrogenators 4 are in the unused state; all hydrogenators 4 are in the pre-cooling state.

[0049] In summary, the principle of the one-pump, multi-gun liquid hydrogen filling control method provided in this embodiment is as follows: a target pressure differential between the front and rear ends of the backpressure device 6 is pre-set in the controller. When no hydrogenator 4 is in the filling state, and a hydrogenator 4 is preparing to fill hydrogen and begin precooling, that is, when the second on-off valve 42 is open, the controller controls the backpressure device 6 to fully open, directly connecting the liquid inlet line 3 to the liquid return line 5. Liquid hydrogen is rapidly pumped into the hydrogenator 4 through the submersible pump 2 and circulated back to the liquid hydrogen storage tank 1, thereby rapidly precooling the hydrogenator 4. When one or more hydrogenators 4 are in the filling state, and a hydrogenator 4 that is not in the filling state starts the pre-cooling work before filling, the controller calculates the actual pressure difference before and after the back pressure device 6 by obtaining the pressure data of the first pressure monitoring device 7 and the second pressure monitoring device 8. Through the PID algorithm, according to the difference between the actual pressure difference before and after the back pressure device 6 and the target pressure difference, the opening and closing degree of the back pressure device 6 is controlled, so that the actual pressure difference quickly reaches the target pressure difference and stably maintains the target pressure difference, avoiding the actual pressure difference from oscillating near the target pressure difference. Avoiding the situation where a hydrogenator 4 is in the filling state and another hydrogenator 4 is ready to fill and start pre-cooling, causing the liquid inlet pipeline 3 to be directly connected to the liquid return pipeline 5, further causing the pressure in the liquid inlet pipeline 3 to decrease instantly, causing the hydrogenator 4 being filled to stop, so that a hydrogenator 4 can be pre-cooled while another hydrogenator 4 is filling.

[0050] Preferably, when the hydrogenator 4 is in the filling state, the controller controls the hydrogenator 4 in the filling state to disconnect the liquid return line 5 from the liquid inlet line 3; when the hydrogenator 4 is in the pre-cooling state, the controller controls the hydrogenator 4 in the pre-cooling state to connect the liquid return line 5 with the liquid inlet line 3. In this embodiment, specifically, when the hydrogenator 4 is in an unused state, the controller controls both the first on-off valve 41 and the second on-off valve 42 to be closed; when the hydrogenator 4 is in the filling state, the first on-off valve 41 in the filling hydrogenator 4 is opened, and the second on-off valve 42 is closed; when the hydrogenator 4 is in the pre-cooling state, the first on-off valve 41 in the pre-cooling hydrogenator 4 is closed, and the second on-off valve 42 is opened.

[0051] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make many possible changes and modifications to the technical solution of the present invention using the above technical content, or modify it into an equivalent embodiment with equivalent changes. Therefore, any changes, modifications, equivalent changes, and modifications made to the above embodiments based on the technology of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the present technical solution.

Claims

1. A one-pump-multiple-gun liquid hydrogen filling control method, characterized in that: include: A liquid hydrogen storage tank (1) for storing liquid hydrogen, wherein the liquid hydrogen storage tank (1) is provided with a first pressure monitoring device (7); a submersible pump (2), which is connected to the liquid hydrogen storage tank (1) via a pipeline; A hydrogenator (4), wherein a plurality of the hydrogenators (4) are connected to the submersible pump (2) via a liquid inlet pipeline (3); A liquid return pipeline (5), wherein a plurality of hydrogenators (4) are connected to the liquid hydrogen storage tank (1) via the liquid return pipeline (5), a back pressure device (6) for controlling the opening and closing degree of the pipeline is provided on the liquid return pipeline (5), and a second pressure monitoring device (8) is provided on the liquid return pipeline (5) between the back pressure device (6) and the hydrogenator (4); A controller, wherein the first pressure monitoring device (7), the second pressure monitoring device (8), the hydrogenator (4) and the back pressure device (6) are all electrically connected to the controller, and the controller is used to control the opening and closing degree of the back pressure device (6); The specific steps include: Preset target pressure difference Pm before and after the back pressure device (6); Obtaining the working state of the hydrogenator (4), the pressure data P1 of the first pressure monitoring device (7), and the pressure data P2 of the second pressure monitoring device (8); Calculate the actual pressure difference before and after the back pressure device (6): Pm' = P2 - P1; According to whether the hydrogenator (4) is in a filling state, a pre-cooling state, or an unused state, the opening and closing degree of the back pressure device (6) is adjusted as follows: If a hydrogenation machine (4) is in a filling state and a hydrogenation machine (4) is in a pre-cooling state, the opening and closing degree of the back pressure device (6) is controlled to control P2 so that Pm=Pm'; If all hydrogen filling machines (4) are not in the filling state, the back pressure device (6) is controlled to be fully opened.

2. The one-pump-multiple-gun liquid hydrogen filling control method according to claim 1, characterized in that: The hydrogenator (4) comprises a filling gun, a first on-off valve (41) and a second on-off valve (42); the liquid inlet pipeline (3) is connected to the filling gun and the liquid return pipeline (5) respectively; the first on-off valve (41) is provided between the liquid inlet pipeline (3) and the filling gun, and the second on-off valve (42) is provided between the liquid inlet pipeline (3) and the liquid return pipeline (5).

3. The one-pump-multiple-gun liquid hydrogen filling control method according to claim 2, characterized in that: The first on-off valve (41) and the second on-off valve (42) both comprise pneumatic valves.

4. The one-pump-multiple-gun liquid hydrogen filling control method according to claim 1, characterized in that: The first pressure monitoring device (7) and the second pressure monitoring device (8) both include a pressure transmitter.

5. The one-pump-multiple-gun liquid hydrogen filling control method according to claim 1, characterized in that: The back pressure device (6) comprises a proportional valve.

6. The one-pump-multiple-gun liquid hydrogen filling control method according to claim 1, characterized in that: The controller includes an MCU or a PLC.

7. The one-pump-multiple-gun liquid hydrogen filling control method according to claim 1, characterized in that: The first pressure monitoring device (7) and the second pressure monitoring device (8) are respectively connected to a pressure display device (9).

8. The one-pump-multiple-gun liquid hydrogen filling control method according to claim 1, characterized in that: A safety valve (10) is provided between the back pressure device (6) on the liquid return pipeline (5) and the liquid hydrogen storage tank (1).

9. The one-pump-multiple-gun liquid hydrogen filling control method according to claim 1, characterized in that: When the hydrogenator (4) is in a filling state, the controller controls the hydrogenator (4) in the filling state to disconnect the return liquid pipeline (5) from the liquid inlet pipeline (3); when the hydrogenator (4) is in a precooling state, the controller controls the hydrogenator (4) in the precooling state to connect the return liquid pipeline (5) to the liquid inlet pipeline (3).

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