Hydrogen equipment leakage detection device and detection method

Abstract

The invention provides a hydrogen equipment leakage detection device and detection method. The hydrogen equipment leakage detection device comprises a first detection assembly, a second detection assembly and a determination unit, the first detection assembly and the second detection assembly are arranged in pairs and used for detecting gas concentration, and the second detection assembly can be controlled to change the orientation of a sensing surface of the second detection assembly; wherein when the determination unit determines that the first detection data sensed by the first detection assembly meets a preset condition, the orientation of the sensing surface of the second detection assembly is controlled to traverse a potential leakage source located in a sensing area of the second detection assembly within a preset time interval; and the determination unit determines whether the potential leakage source has hydrogen equipment leakage or not according to the second detection data sensed by the second detection assembly. According to the invention, whether hydrogen equipment leakage occurs in potential leakage sources in an environment in which gas and liquid hydrogen and other parts are densely arranged in a limited space can be accurately judged.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of hydrogen energy equipment, and particularly relates to a hydrogen equipment leakage detection device and a detection method. BACKGROUND

[0002] In the links of hydrogen energy production, preparation, storage, transportation and utilization, there are often situations of densely arranging liquid hydrogen, gaseous hydrogen and other gas / liquid medium process pipelines, containers and components in a limited space. In the existing leakage safety monitoring technology, one or more different types of sensors are usually combined, such as catalytic combustion type, electrochemical type, hydrogen-sensitive palladium alloy type and heat conduction type single hydrogen concentration sensor or array installed near the leakage site for detection.

[0003] The above-mentioned detection technology can easily obtain a conclusion that leakage occurs in a certain area, but there is a significant deficiency in determining the specific source of leakage. Because the actual completion function, operating pressure, sealing state and other working conditions of liquid hydrogen, gaseous hydrogen and other gas medium pipelines, containers and components are different, the risk level and the urgency of treatment after leakage are also different, so it is necessary to determine the specific source of leakage in practice.

[0004] In some applications, it is required to jointly determine by coupling process system parameters, which is not conducive to the implementation of the independent operation principle of the hydrogen leakage safety monitoring system, and increases the complexity and failure rate of the system. The single type sensor detection has deficiencies, and sometimes false alarms or large lags are easily generated. For example, the ultrasonic leakage sensor has a high probability of false negatives for leakage under a lower pressure level of 1.0 MPa, because the acoustic signal intensity in the detection frequency spectrum is significantly reduced. The catalytic combustion type and electrochemical type sensors have a relatively slow response speed, and because oxygen in the air is required, for the scene of liquid hydrogen leakage and expansion diffusion leading to rapid reduction of oxygen content in the air, false alarms are easily generated.

[0005] Therefore, the present application is proposed. SUMMARY

[0006] The technical problem to be solved by the present application is to at least overcome part of the deficiencies of the prior art, and to provide a hydrogen equipment leakage detection device. The first detection component and the second detection component are arranged in pairs to detect the gas concentration, and the second detection component can change the orientation of its sensing surface. The first detection component is used for preliminary determination, and then the second detection component is used for coupled determination under the condition of changing its working state. The data perceived by the second detection component can accurately determine whether hydrogen equipment leakage occurs in the potential leakage source in the environment of densely arranged gaseous hydrogen, liquid hydrogen and other components in a limited space.

[0007] To solve the above technical problems, the basic idea of the technical scheme is to provide a hydrogen equipment leakage detection device in the first aspect, comprising a first detection component, a second detection component, and a determination unit, the first detection component and the second detection component are configured in pairs for detecting gas concentration, and the orientation of the sensing surface of the second detection component can be controlled to change;

[0008] When the determination unit determines that the first detection data sensed by the first detection component meets the preset condition, the orientation of the sensing surface of the second detection component is controlled to traverse the potential leakage source within the sensing area of the second detection component within a preset time interval.

[0009] The determination unit determines whether the potential leakage source leaks hydrogen according to the second detection data sensed by the second detection component.

[0010] In some embodiments, the first detection component includes a first sensor and a first power unit, the first sensor can be controlled to switch between a first concentration detection mode and a first temperature detection mode, and the first power unit can be controlled to provide power to the gas passing through the first sensor;

[0011] The second detection component includes a second sensor and a second power unit, the second sensor can be controlled to switch between a second concentration detection mode and a second temperature detection mode, and the orientation of the sensing surface thereof can be controlled to change, and the second power unit can be controlled to provide power to the gas passing through the second sensor;

[0012] The first detection data is the first concentration or the first temperature, and the second detection data is the second concentration or the second temperature.

[0013] Preferably, the first sensor and the second sensor are thermal conductivity gas sensors.

[0014] Preferably, the first power unit and the second power unit are negative pressure pumps, and are respectively arranged at the gas outlet ends of the first sensor and the second sensor.

[0015] In some embodiments, the first detection component further includes a gas flow impact blocking unit configured to be installed at the sensing surface of the first sensor for stabilizing the gas flow velocity of the gas flowing to the first sensor.

[0016] Preferably, the gas flow impact blocking unit includes a stainless steel sintered filter sheet.

[0017] In some embodiments, the internal microstructure unit of the first sensor and the second sensor adopts a lateral inlet diffusion air inlet mode.

[0018] Preferably, the second sensor has a lateral gas inlet opposite to a lateral opening of the heating conductive film thereof.

[0019] The second aspect of the present application provides a hydrogen equipment leakage detection method using the hydrogen equipment leakage detection device as described above, comprising:

[0020] Under the condition that the first power unit is not started, the first sensor is controlled to be in a first concentration detection mode, and a first concentration sensed by the first sensor is collected;

[0021] When it is determined that the first concentration increases from not more than N1Z to not less than N11A within a T11 time interval, the first power unit is controlled to be started;

[0022] When it is determined that the average value of the first concentration detected within a T12 time interval gradually increases, the orientation of the sensing surface of the second sensor is controlled to traverse potential leakage sources within the sensing area of the second sensor within a T13 time interval, and a second concentration sensed by the second sensor is collected;

[0023] When it is determined that the detection peak value of the second concentration collected within the T13 time interval is not less than 1.5*N11A, and the average value is greater than N11A, it is determined that the potential leakage source causes liquid hydrogen leakage.

[0024] In some embodiments, when it is determined that the first concentration increases from not more than N1Z to not less than 1.5*N11A within a T11 time interval, it is determined that the potential leakage source causes liquid hydrogen leakage.

[0025] The third aspect of the present application provides a hydrogen equipment leakage detection method using the hydrogen equipment leakage detection device as described above, comprising:

[0026] Under the condition that the first power unit is started at a preset frequency, the first sensor is controlled to be in a first concentration detection mode, and a first concentration sensed by the first sensor is collected;

[0027] When it is determined that the output value of the first concentration reaches N21A within a T21 time interval, the orientation of the sensing surface of the second sensor is controlled to traverse a plurality of potential leakage sources within the sensing area of the second sensor, and stay at the position of each potential leakage source for a T22 time interval;

[0028] In each T22 time interval, the second power unit is controlled to be switched between starting and stopping, and a second concentration sensed by the second sensor is collected;

[0029] If the average values of the second concentrations collected in the T22 time interval in the start and stop states are not less than N22A and N22B respectively in at least one orientation of the second sensor, it is preliminarily determined that the potential leakage source corresponding to the orientation leaks pressurized hydrogen.

[0030] In some embodiments, the first sensor is controlled to switch to a first temperature detection mode, the second sensor is controlled to switch to a second temperature detection mode, and a sensing surface of the second sensor is controlled to be kept in a direction towards a potential leakage source leaking hydrogen, the first power unit and the second power unit are turned off, and the first temperature and the second temperature sensed by the first sensor and the second sensor respectively are collected.

[0031] If the difference between the average temperature values Tr21 and Tr22 of the first temperature and the second temperature sensed in the T23 time interval is not less than a preset temperature threshold, it is determined that the potential leakage source corresponding to the orientation leaks pressurized hydrogen.

[0032] The fourth aspect of the present application provides a hydrogen equipment leakage detection method using the hydrogen equipment leakage detection device described above, comprising:

[0033] Under the condition that the first power unit is started according to a preset frequency, the first sensor is controlled to be in a first concentration detection mode, and the first concentration sensed by the first sensor is collected.

[0034] If the output value of the first concentration in the T31 time interval is not greater than N31A, the second sensor is controlled to rotate according to a preset angle, so that the orientation of the sensing surface thereof is changed in the potential leakage source areas in turn, and when the orientation of the sensing surface of the second sensor is in a certain direction of the potential leakage source areas, the second sensor stays in the direction for a T32 time interval, and the fluctuation range of the output value of the second sensor in the second concentration detection mode in the T32 time interval is recorded, so as to obtain a plurality of fluctuation ranges.

[0035] If the maximum value of at least one of the fluctuation ranges is not less than N32Tmax and the minimum value is not less than N32Tmin, it is determined that the potential leakage source near the orientation leaks non-hydrogen medium.

[0036] In some embodiments, the hydrogen equipment leakage detection method further comprises: obtaining the orientation of the side gas inlet of the second sensor in the T32 time interval.

[0037] It is determined that the potential leakage source near the orientation of the side gas inlet of the second sensor leaks non-hydrogen medium.

[0038] Compared with the prior art, the application has the following beneficial effects.

[0039] The hydrogen equipment leakage detection device and method provided by the application can accurately determine whether hydrogen equipment leakage occurs in a potential leakage source in a limited space densely arranged with gas and liquid hydrogen and other components.

[0040] The specific embodiments of the application are described in further detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0041] The accompanying drawings, which are part of the present application, serve to provide a further understanding of the application, and the illustrative embodiments of the application and their descriptions serve to explain the application, but do not constitute an improper limitation on the application. Obviously, the accompanying drawings described below are only some embodiments, and other drawings can be obtained by those skilled in the art without creative labor. In the drawings:

[0042] Figure 1 is a partial structure schematic diagram of a hydrogen equipment leakage detection device provided according to an exemplary embodiment of the application;

[0043] Figure 2 is a detection inlet air process schematic diagram of a first sensor provided according to an exemplary embodiment of the application;

[0044] Figure 3 is a side detection inlet air process schematic diagram of a second sensor provided according to an exemplary embodiment of the application.

[0045] In the drawings: 100, hydrogen equipment leakage detection device;

[0046] 10, first detection assembly; 11, first sensor; 12, first power unit; 13, first concentration detection unit; 14, first temperature detection unit; 15, air flow impact barrier unit;

[0047] 20, second detection assembly; 21, second sensor; 22, second power unit; 23, second concentration detection unit; 24, second temperature detection unit;

[0048] 30, sensor shell; 31, base layer; 32, ambient temperature detection resistor; 33, heating conductive film; 34, film heating resistor; 35, side inlet; 36, sensing surface; 37, side gas inlet; 38, side opening.

[0049] It should be noted that the drawings and detailed description are not intended to limit the scope of the inventive concept in any way, but to illustrate the inventive concept to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments will be described clearly and completely below with reference to the drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application, but are not used to limit the scope of the present application.

[0051] In the description of the present application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0052] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0053] Figure 1 A partial structural schematic diagram of a hydrogen equipment leakage detection device 100 provided according to an exemplary embodiment of the present application is shown. The detection device preferably detects whether hydrogen equipment leakage occurs from potential leakage sources in an environment where gas, liquid hydrogen and other components are densely arranged in a limited space.

[0054] As shown in Figure 1 The hydrogen equipment leakage detection device 100 includes a first detection assembly 10, a second detection assembly 20 and a determination unit (not shown), the first detection assembly 10 and the second detection assembly 20 are arranged in pairs for detecting gas concentration, and the second detection assembly 20 can be controlled to change the orientation of its sensing surface 36. Wherein, when the determination unit determines that the first detection data perceived by the first detection assembly 10 meets the preset condition, the orientation of the sensing surface 36 of the second detection assembly 20 is controlled to traverse the potential leakage sources located in the sensing area of the second detection assembly 20 within a preset time interval; the determination unit determines whether hydrogen equipment leakage occurs from the potential leakage sources according to the second detection data perceived by the second detection assembly 20.

[0055] In the above scheme, the first detection component 10 and the second detection component 20 are configured in pairs to detect the gas concentration, and the second detection component 20 can change the orientation of the sensing surface 36, and the preliminary determination is made by using the first detection component 10, and then the coupling determination is made by using the data sensed by the second detection component 20 under the condition of changing the working state, so that the hydrogen equipment leakage of the potential leakage source in the environment where the gas, liquid hydrogen and other components are densely arranged in the limited space can be accurately determined.

[0056] In other words, in the above scheme of the present application, the problem that a single sensor cannot determine the specific leakage source can be solved, and the problem that the system is complex due to the arrangement of multiple sensors, which is not conducive to the detection of the leakage in the limited space, can also be solved.

[0057] In some embodiments, as shown in Figure 1 The first detection component 10 includes a first sensor 11 and a first power unit 12, the first sensor 11 is controllable to switch between a first concentration detection mode and a first temperature detection mode, and the first power unit 12 is controllable to provide power to the gas passing through the first sensor 11. The second detection component 20 includes a second sensor 21 and a second power unit 22, the second sensor 21 is controllable to switch between a second concentration detection mode and a second temperature detection mode, and the orientation of the sensing surface 36 can be changed, and the second power unit 22 is controllable to provide power to the gas passing through the second sensor 21, as shown in Figure 3 The first detection data is the first concentration or the first temperature, and the second detection data is the second concentration or the second temperature.

[0058] The first detection component 10 further includes a first concentration detection unit 13 and a first temperature detection unit 14, and the first sensor 11 is controllable to be switchably connected to the first concentration detection unit 13 and the first temperature detection unit 14, so as to achieve the purpose of switching between the first concentration detection mode and the first temperature detection mode. Similarly, the second detection component 20 further includes a second concentration detection unit 23 and a second temperature detection unit 24, and the second sensor 21 is controllable to be switchably connected to the second concentration detection unit 23 and the second temperature detection unit 24, so as to achieve the purpose of switching between the second concentration detection mode and the second temperature detection mode. The determination unit is connected to the first concentration detection unit 13 and the first temperature detection unit 14, so as to collect the first concentration and the first temperature, and the determination unit is connected to the second concentration detection unit 23 and the second temperature detection unit 24, so as to collect the second concentration and the second temperature.

[0059] The determining module is, for example, a server or other device having computing power that is capable of processing data collected by the first detection component 10 and the second detection component 20 to determine whether a hydrogen device leak has occurred.

[0060] It should be noted that the first concentration detection unit 13 and the first temperature detection unit 14, and the second concentration detection unit 23 and the second temperature detection unit 24 can adopt structures commonly used in the art, and the present application does not limit this.

[0061] In the above scheme, the first sensor 11 and the second sensor 21 can be MEMS type thermal conductivity gas sensors. The detection range is at least 0.1-10% Vol, and the volume of the micro thermal conductivity cell is not more than 10 uL. The first sensor 11 and the second sensor 21 are respectively installed on two different micro gimbals. The first sensor 11 is fixedly installed or controllably adjusted in position, and a gas flow impact blocking unit 15 is arranged at the sensing surface 36 of the first sensor 11 to stabilize the gas flow velocity of the gas flowing to the first sensor 11. As an example, the gas flow impact blocking unit 15 includes a stainless steel sintered filter sheet, the particle size of the stainless steel sintered filter sheet can be set according to actual needs, and the gas flow impact blocking unit 15 is installed in parallel close to the sensing surface 36 of the first sensor 11. The second sensor 21 is controllably adjusted in position to change the orientation of the sensing surface 36, and it is particularly pointed out that the sensing surface 36 of the second sensor 21 is not provided with a gas flow impact blocking unit 15.

[0062] The response time T90 of the first sensor 11 is not more than 2.5s, and the recovery time T10 is not more than 10s. The response time T90 of the second sensor 21 is not more than 1s, and the recovery time T10 is not more than 3s.

[0063] Referring to Figure 2 As shown in the figure, the first sensor 11 includes a sensor housing 30 and a substrate layer 31 arranged in the sensor housing 30, an ambient temperature conductive film and a heating conductive film 33 are arranged above the substrate layer 31, an ambient temperature detection resistor 32 is arranged in the ambient temperature conductive film, a film heating resistor 34 is arranged in the heating conductive film 33, the heating conductive film 33 has a lateral opening 38, and a sensor sensing surface 36 is arranged above the heating conductive film 33. The edges of the sensor sensing surface 36 and the sensor housing 30 form a lateral inlet 35. The leaked gas flows to the ambient temperature detection resistor 32 and the heating conductive film 33 through the lateral inlet 35, respectively.

[0064] Referring to Figure 3 As shown in the figure, in addition to the structures included in the first sensor 11, a lateral gas inlet 37 opposite to the heating conductive film 33 is also formed on the sensor housing 30 of the second sensor 21.

[0065] In an implementable embodiment, the first sensor 11 is a complete package, and the lateral inlet 35 of the internal microstructure unit is not exposed to the detection environment, i.e. not in direct contact with the ambient gas. Therefore, when detecting the concentration, the gas to be sensed can only pass through the sensing surface 36 at a low flow rate, and then diffuse and exchange through the internal lateral inlet 35 under a steady state. The second sensor 21 is a non-complete package, and the sensing surface 36 and the lateral inlet 35 of the internal microstructure unit are both exposed to the detection environment, and can be in direct contact with the ambient gas, as shown in Figure 2 and Figure 3 .

[0066] In other words, the internal microstructure unit of the first sensor 11 and the second sensor 21 adopts a lateral inlet 35 diffusion inlet mode, and the axis direction of the lateral opening 38 of the heating conductive film 33 is perpendicular to the normal direction of the sensing surface 36, i.e. perpendicular to the external cover surface. When detecting the concentration, the gas to be sensed can only pass through the sensing surface 36 at a low flow rate, and then flow to the heating conductive film 33 through the internal lateral inlet 35, so as to realize the diffusion and exchange of the gas, and then realize the concentration detection according to the difference in the thermal conductivities before and after.

[0067] Preferably, as shown in Figure 1 , the first power unit 12 and the second power unit 22 are negative pressure pumps, and are respectively arranged at the gas outlet ends of the first sensor 11 and the second sensor 21, and are connected with the sensor shell 30. After the first power unit 12 and the second power unit 22 are started, the external gas in the surrounding area can enter the first sensor 11 and the second sensor 21 more.

[0068] It can be understood that the potential leakage source mentioned above, for example, is a place where leakage is prone to occur, such as a pipe joint, a welding point, etc. in a hydrogen pipeline system, a storage system, a filling system, and can also occur on the surface of a pipeline, the surface of a tank, a hydrogen / hydrogen filling port, a hydrogen compressor, etc.

[0069] According to the hydrogen leakage mode and the working pressure of the hydrogen equipment, the hydrogen leakage mode of the potential leakage source is divided into a liquid hydrogen leakage mode, a pressurized gas hydrogen leakage mode, and a non-hydrogen medium leakage mode.

[0070] For example, for a liquid hydrogen storage or transportation system, the working pressure is generally 0.8 MPa, so the first pressure level corresponding to the liquid hydrogen leakage mode is marked as 0.8 MPa; for a high-pressure hydrogen gas delivery system, the working pressure is 15 MPa, so the second pressure level corresponding to the pressurized hydrogen leakage mode is marked as 15 MPa; for an instrument gas pressure of nitrogen or other non-hydrogen medium, the pressure is 0.4 MPa, so the third pressure level corresponding to the non-hydrogen medium leakage mode is marked as 0.4 MPa.

[0071] To improve the accuracy of hydrogen equipment leakage detection, the first pressure level applicable to the hydrogen equipment leakage detection device 100 provided by the present application is not less than 0.2 MPa, the second pressure level is not less than 2.5 MPa, and the third pressure level is not less than 0.3 MPa.

[0072] It should be noted that the number of each mode varies depending on the specific application environment, and the present application does not limit this.

[0073] After dividing the hydrogen equipment leakage modes, the locations of each mode can be marked in the system, and the hydrogen equipment leakage detection device 100 described above can be installed at the location of each mode.

[0074] As an example, when the first sensor 11 is fixedly installed, each potential leakage source is located within a 60-degree conical angle region with the center of the sensing surface 36 of the first sensor 11 as the apex. When the first sensor 11 is installed in a controlled adjustable orientation, each potential leakage source is located in a certain directly facing direction within the movable range of the sensing surface 36 of the first sensor 11, ensuring that the leakage can diffuse to the sensing surface 36 of the first sensor 11 after the leakage occurs.

[0075] For the second sensor 21, it is installed in a controlled adjustable orientation, and each potential leakage source is located in a certain directly facing direction within the movable range of the sensing surface 36 of the second sensor 21, ensuring that the leakage can diffuse to the sensing surface 36 of the second sensor 21 after the leakage occurs.

[0076] In an implementable manner, the change in the orientation of the sensing surface 36 of the first sensor 11 and the second sensor 21 can be achieved by controlling the rotation of the micro gimbal.

[0077] It should be noted that, since the first sensor 11 and the second sensor 21 are arranged in pairs, after the installation position of the first sensor 11 is determined, the installation position of the second sensor 21 can also be determined correspondingly. The initial installation height of the two is the same, and the lateral distance is not greater than 60 mm. Moreover, regardless of whether the first sensor 11 is installed in a fixed manner or in an adjustable manner, the installation positions of the first sensor 11 and the second sensor 21 should be slightly higher than each potential leakage source in the vertical direction, and the maximum height difference is not more than 0.5 meters, and the maximum lateral distance is not more than 2.0 meters.

[0078] It can be seen that the arrangement positions of the first sensor 11 and the second sensor 21 are not uniquely defined, and as long as the following conditions are met within a certain area, it provides convenience for practical application.

[0079] It should be noted that the working state and detection principle of the hydrogen equipment leakage detection device 100 at different leakage modes are different, and therefore, after the first sensor 11 and the second sensor 21 are arranged in different areas, the detection effect of the first sensor 11 and the second sensor 21 in the area should also be verified.

[0080] The following refers to Figures 1 to 3 The verification process is described in detail.

[0081] According to the actual spatial positions of the potential leakage sources of the system, the simulated leakage sources are arranged respectively, and the simulated objects are taken, that is, the medium and the corresponding pressure in the actual potential leakage source in operation are discharged.

[0082] When simulating the liquid hydrogen leakage mode, the liquid hydrogen leakage is released from the single-end opening pipeline after the liquid hydrogen storage container is connected with the valve. Preferably, the diameter size of the release pipeline is 1.0-3.0 mm. In addition, in the simulation verification, when it is not convenient to use liquid hydrogen medium, low-temperature hydrogen gas after being fully subcooled by liquid nitrogen should be used to replace the medium, and the outlet temperature is not higher than 100 K. The low-temperature hydrogen gas is connected with the valve and released through the single-end opening pipeline after adiabatic insulation treatment, and the diameter of the first standard leakage hole is preferably 0.3-1.0 mm.

[0083] When simulating the pressurized gas hydrogen leakage mode, the same hydrogen source as the second pressure level is used, which is connected with the valve and released through the single-end opening pipeline, and the diameter of the second standard leakage hole is preferably 0.1-0.5 mm.

[0084] When simulating the non-hydrogen medium leakage mode, the medium used is equivalent to the non-hydrogen medium in the actual running system, for example, the instrument control gas required by the pneumatic valve is usually nitrogen. The same non-hydrogen medium source as the third pressure level is used, which is connected with the valve and released through the single-end opening pipeline, and the diameter of the third standard leakage hole is preferably 0.3-1.0 mm.

[0085] (1) In the simulation test of liquid hydrogen leakage mode, when the lower limit of the standard leakage hole diameter is taken, the test can be started from the position farthest from the distance sensor, and the timing starts from the zero point when the simulation leakage occurs. The first sensor 11 works in the first concentration detection mode with air flow impact barrier unit 15 and without starting the first power unit 12, and the output reaches threshold N11A within T11 time. In the first concentration detection mode with the first power unit 12 started, the output of the first sensor 11 reaches threshold N11B under the same conditions. When there is no leakage, the maximum concentration detection value of the output of the first sensor 11 is N1Z. Due to the low pressure characteristics of liquid hydrogen leakage, the detection of the first sensor 11 in this mode meets the steady-state gas detection after diffusion, and is not affected by the interference signal caused by the direct impact of air flow.

[0086] It should be noted that in the simulation test of this mode, only the data of the first sensor 11 is tested to obtain the judgment condition required in the subsequent actual test process, so the data of the second sensor 21 does not need to be verified. However, in the second indirect verification condition for judging whether the liquid hydrogen leakage mode occurs, the detection data of the second sensor 21 can be used for enhanced judgment.

[0087] Wherein, T11 is not less than the response time of the first sensor 11. N1Z is not greater than 0.05% Vol, N11A is not less than 0.15% Vol, and N11B is not less than 2.5 times of N11A. This is because under the power of the power unit, the ambient gas can be gathered, and a higher value of gas concentration can be detected, so the sensor output threshold is larger.

[0088] (2) In the simulation test of the hydrogen leakage mode under pressure, when the standard leakage hole lower limit is reached, the first sensor 11 works in the first concentration detection mode with the gas flow impact barrier unit 15 and the first power unit 12 activated, and outputs a threshold value N21A within T21 time; the second sensor 21 is controlled to change the orientation so that its sensing surface 36 is directly opposite the simulation leakage source, and the second concentration detection mode is activated without activating the second power unit 22, and the average value detected within T22 time after the simulation leakage source leaks is N22A or N22B. When the simulation leakage source does not leak, the maximum concentration detection values of the first sensor 11 and the second sensor 21 are N1Z and N2Z, respectively. After the test is completed, the first sensor 11 and the second sensor 21 are switched from the first concentration detection mode and the second concentration detection mode to the first temperature detection mode and the second temperature detection mode, respectively, the first power unit 12 and the second power unit 22 are turned off, and the current position of the second sensor 21 is maintained. After the leakage is restarted, the initial temperature values T21A and T22A of the first sensor 11 and the second sensor 21 are recorded, the temperature difference T21A-T22A is recorded as ΔTA, the average temperature values Tr21 and Tr22 of the first sensor 11 and the second sensor 21 within T23 are recorded, and the temperature difference Tr21-Tr22 is recorded as ΔT, wherein the absolute value of ΔTA is not higher than T0, Tr21>Tr22, T21A>T22A, and ΔT is not lower than a threshold value T1.

[0089] This is because, after the simulation leakage starts, under the action of a higher initial pressure, the direction concentration effect of hydrogen leakage is stronger, and the accumulative diffusion effect is weaker. T22 is not lower than the response time of the second sensor 21. T23 is not lower than the response time of the first sensor 11. In the condition that the first sensor 11 works with the gas flow impact barrier unit 15, the influence of the disturbance signal caused by the direct impact of the gas flow is greatly eliminated. However, under the condition that the diameter of the leakage hole is small and the pressure is relatively low, the leakage amount per unit time will decrease, and the concentration reaching the sensor detection point will also decrease. At this time, the influence of activating the first power unit 12 and the second power unit 22 on the detection concentration peak is more obvious. At the same time, the mode can be changed, and the second sensor 21 without the gas flow impact barrier unit 15 can be more sensitive to the perception of hydrogen-containing gas flow in the temperature detection mode. The above method ensures the reliability of the analysis under different leakage modes.

[0090] Wherein, T21 is not lower than the response time of the first sensor 11, T22 and T23 are not lower than the response time of the second sensor 21. N21A is not less than 0.08% Vol., N22A is not less than 0.1% Vol., N22B is not less than 1.5 times of N22A, N1Z and N2Z are both not greater than 0.05% Vol. T0 is 1℃. T1 is 5℃.

[0091] (3) In the non-hydrogen medium leakage mode, at the standard leak hole lower limit, the first sensor 11 records the output value in the first concentration detection mode before and after starting the first power unit 12, and the output value in the T31 time interval is not greater than the threshold N31A; the second sensor 21 does not start the second power unit 22, and the initial output value in the second concentration detection mode is N32Z, then the second sensor 21 is controlled to rotate according to the preset angle, so as to change the orientation of the sensing surface 36 in the area of the plurality of simulated leakage sources in turn, and when the orientation of the sensing surface 36 of the second sensor 21 is located in a certain direction of the plurality of simulated leakage sources, it stays in this direction, and the stay time is T32, and the fluctuation range of the output value of the second sensor 21 in the second concentration detection mode is recorded in the T32 time interval, so as to obtain a plurality of fluctuation ranges. Analyzing a plurality of fluctuation ranges can determine the maximum fluctuation range, and the maximum value of the maximum fluctuation range is recorded as N32Tmax, and the minimum value is recorded as N32Tmin. Since the second sensor 21 has a side gas inlet 37, it can be analyzed that the maximum fluctuation range is obtained when the sensing surface 36 of the second sensor 21 is adjusted to a certain direction and the direction is not directly opposite to the simulated leakage source. When the sensing surface 36 of the second sensor 21 is adjusted to directly opposite the simulated leakage source, the maximum output value is not greater than 1.5*N32Z.

[0092] It should be noted that the time interval required for the sensing surface 36 of the second sensor 21 to rotate from one direction to another direction is T33.

[0093] In this mode, after the non-hydrogen gas medium with low thermal conductivity leaks, a certain airflow speed directly acts on the internal microstructure unit of the first sensor 11 and the second sensor 21. This mode causes the thermal conductivity sensor to produce false signal drift in a non-steady state diffusion mode, and the strong-weak mutation characteristics of the signal in the moving process of the sensing surface 36 are obviously different from the steady state diffusion in normal detection.

[0094] Wherein, T31 is not less than the response time of the first sensor 11, T32 is not less than the response time of the second sensor 21, it should be noted that T33 should be shortened as much as possible according to the adjustment ability of the micro gimbal to improve the detection accuracy, however, on the basis of considering the cost, T33 is not higher than 1 / 3 of the recovery time of the second sensor 21. N31A, N32Z is not greater than 0.05%Vol, N32Tmax is not less than 0.4%Vol, N32Tmin is not greater than 0.2*N32Tmax.

[0095] The above leakage hole diameter size is obtained from the actual accumulated experience data. If the early warning requirement for leakage is higher, the leakage hole diameter can be reduced as needed, the above verification method remains unchanged, but the effective leakage monitoring range of the first sensor 11 and the second sensor 21 will be reduced, the number of sensors to be arranged will be increased, and the system cost will be improved.

[0096] When a single sensor cannot meet the above requirements, multiple sensors should be installed for simultaneous detection.

[0097] Under the condition of meeting the above test results, it can be determined that the leakage of the potential leakage source under each leakage mode can be detected.

[0098] The following will be described with reference to Figures 1 to 3 The process of how to detect the three hydrogen leakage modes in the actual production process will be described in detail.

[0099] (1) According to the detection results of the first sensor 11 and the second sensor 21, it is determined whether the liquid hydrogen leakage mode occurrence condition is met.

[0100] Specifically, under the condition that the first power unit 12 is not started, the first sensor 11 is controlled to be in the first concentration detection mode, and the first concentration sensed by the first sensor 11 is collected, so that after the medium in the environment leaks and passes through the airflow impact barrier unit 15, it diffuses to the first sensor 11 stably, so that the thermal conductivity changes, and the concentration detection is realized according to the established basis.

[0101] When it is determined that the first concentration increases from not greater than N1Z to not less than N11A within the T11 time interval, the first and second indirect verification conditions are performed.

[0102] Specifically, the first power unit 12 is controlled to be started, and when it is determined that the average value of the first concentration detected within the T12 time interval gradually increases, the first indirect verification condition is established. At this time, the orientation of the sensing surface 36 of the second sensor 21 is changed, the orientation of the sensing surface 36 of the second sensor 21 is controlled to traverse the potential leakage source in the sensing area of the second sensor 21 within the T13 time interval, and the second concentration sensed by the second sensor 21 is collected; when it is determined that the detection peak value of the second concentration collected within the T13 time interval is not less than 1.5*N11A, and the detection average value is greater than N11A, the second verification condition is established, and it is determined that the potential leakage source has liquid hydrogen leakage. In this process, the second sensor 21 has no airflow impact barrier unit 15, so the concentration detection value changes more dramatically, and therefore the peak value and the average value are combined as the basis for analysis. When the first and second verification conditions are both established, it is analyzed that liquid hydrogen leakage has occurred.

[0103] In addition, when it is determined that the first concentration increases from no greater than N1Z to no less than 1.5*N11A within the time interval T11, liquid hydrogen leakage can be directly determined to have occurred at the potential leakage source without the need for further confirmation by the second sensor 21. It should be noted that at least one potential leakage source is determined.

[0104] (2) Analyze the detection results of the first sensor 11 and the second sensor 21 to determine whether the conditions for the pressurized gas hydrogen leakage mode are met.

[0105] Specifically, under the condition that the first power unit 12 is started at a preset frequency (optionally 0.01 to 0.2 Hz), the first sensor 11 is controlled to be in a first concentration detection mode and the first concentration sensed by the first sensor 11 is collected. When it is determined that the output value of the first concentration reaches N21A within the T21 time interval, the sensing surface 36 of the second sensor 21 is controlled to traverse the direction of multiple potential leakage sources located within the sensing area of ​​the second sensor 21 and remain at the location of each potential leakage source for a T22 time interval. In each T22 time interval, the second power unit 22 is controlled to switch between shutdown and startup, preferably, the startup time accounts for 50% of the T22 time interval, and the second concentration sensed by the second sensor 21 is collected. When it is determined that in at least one direction of the second sensor 21, the average value of the second concentration collected in the shutdown and startup states during the T22 time interval is not less than N22A and N22B, it is preliminarily determined that the potential leakage source corresponding to the direction may have leaked pressurized hydrogen.

[0106] For further verification, the first sensor 11 is controlled to switch to the first temperature detection mode, the second sensor 21 is controlled to switch to the second temperature detection mode, and the sensing surface 36 of the second sensor 21 is controlled to remain facing the potential leakage source of pressurized hydrogen. At the same time, the first power unit 12 and the second power unit 22 are shut down, and the first temperature and the second temperature sensed by the first sensor 11 and the second sensor 21 are collected. When it is determined that the difference between the average temperature values ​​Tr21 and Tr22 of the first temperature and the second temperature sensed within the time interval T23 is not less than a preset temperature threshold, it is determined that pressurized hydrogen leakage has occurred in the direction of the corresponding potential leakage source. The preset temperature threshold is, for example, T1-T0.

[0107] (3) Analyze the detection results of the first sensor 11 and the second sensor 21 to determine whether the conditions for the non-hydrogen medium leakage mode are met.

[0108] Specifically, under the condition that the first power unit 12 is started at a preset frequency, which can be 0.01-0.2 Hz, the first sensor 11 is controlled to be in a first concentration detection mode, and the first concentration sensed by the first sensor 11 is collected; it is determined that the output value of the first concentration in a T31 time interval is not greater than N31A, the second sensor 21 is controlled to rotate at a preset angle, which can be adaptively set according to the actual location of the potential leakage source, so that the orientation of the sensing surface 36 thereof is sequentially changed in the areas where the potential leakage sources are located, and when the orientation of the sensing surface 36 of the second sensor 21 is located in a certain direction of the areas where the potential leakage sources are located, it stays in the direction, and the staying time is T32, the fluctuation range of the output value of the second sensor 21 in a second concentration detection mode in a T32 time interval is recorded, so that a plurality of fluctuation ranges can be obtained. When it is determined that the maximum value of at least one of the fluctuation ranges is not less than N32Tmax and the minimum value is not less than N32Tmin, it is determined that a non-hydrogen medium leakage occurs in the potential leakage source near the orientation.

[0109] It should be explained here that when the sensing surface 36 of the second sensor 21 is oriented in a certain direction and the direction is not directly opposite to the potential leakage source, the air inlet mode of the second sensor 21 is through the side gas inlet 37, and at this time, the maximum fluctuation range is obtained. Since the harm of non-hydrogen medium leakage is usually not great, the urgency of processing is relatively low, and correct identification in this step can be obtained.

[0110] In addition, in order to narrow down the troubleshooting range, the orientation of the side gas inlet 37 of the second sensor 21 in the T32 time interval can also be obtained, so that it is determined that a non-hydrogen medium leakage occurs in the potential leakage source near the orientation of the side gas inlet 37 of the second sensor 21.

[0111] It should be explained here that the selection of the parameters involved in the above process of how to detect the three hydrogen equipment leakage modes in the actual production process can refer to the foregoing verification part, and the present application will not be described here.

[0112] The above only describes the preferred embodiments of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with the preferred embodiments, it is not intended to limit the present application, and any person skilled in the art can make some changes or modifications to the above-mentioned technical content without departing from the technical solution range of the present application, and any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present application still belong to the scope of the present application.

Claims

1. A hydrogen equipment leak detection device, characterized in that: The device comprises a first detection component, a second detection component and a determination unit, wherein the first detection component and the second detection component are configured in pairs for detecting gas concentration, and the second detection component can be controlled to change the orientation of its sensing surface; When the determining unit determines that the first detection data sensed by the first detection component meets a preset condition, the sensing surface of the second detection component is controlled to traverse the potential leakage source located in the sensing area of ​​the second detection component within a preset time interval; The determining unit determines whether a hydrogen equipment leak occurs at a potential leakage source according to the second detection data sensed by the second detection component.

2. The hydrogen equipment leakage detection device according to claim 1, characterized in that: The first detection assembly includes a first sensor and a first power unit, the first sensor can be controlled to switch between a first concentration detection mode and a first temperature detection mode, and the first power unit can be controlled to provide power to the gas passing through the first sensor; The second detection assembly includes a second sensor and a second power unit, the second sensor can be controlled to switch between a second concentration detection mode and a second temperature detection mode, and can be controlled to change the orientation of its sensing surface, and the second power unit can be controlled to provide power to the gas passing through the second sensor; Wherein, the first detection data is a first concentration or a first temperature, and the second detection data is a second concentration or a second temperature; Preferably, the first sensor and the second sensor are thermal conductivity gas sensors; Preferably, the first power unit and the second power unit are negative pressure pumps, and are respectively provided at the gas outlet ends of the first sensor and the second sensor.

3. The hydrogen equipment leakage detection device according to claim 2, characterized in that: The first detection assembly further includes an airflow impact blocking unit configured to be mounted at a sensing surface of the first sensor and configured to stabilize an airflow velocity of the gas flowing toward the first sensor; Preferably, the airflow impact blocking unit comprises a stainless steel sintered filter.

4. The hydrogen equipment leakage detection device according to claim 2, characterized in that: The internal microstructure units of the first sensor and the second sensor adopt a side inlet diffusion intake method; Preferably, the second sensor further has a side gas inlet, and the side gas inlet is opposite to the side opening of the heating conductive film.

5. A hydrogen equipment leak detection method, characterized in that: The hydrogen equipment leakage detection device according to any one of claims 2 to 4 comprises: Under the condition that the first power unit is not started, controlling the first sensor to be in a first concentration detection mode and collecting a first concentration sensed by the first sensor; When it is determined that the first concentration increases from no greater than N1Z to no less than N11A within a time interval T11, controlling the first power unit to start; When it is determined that the average value of the first concentration detected within the time interval T12 gradually increases, controlling the direction of the sensing surface of the second sensor to traverse the potential leakage source located in the sensing area of ​​the second sensor within the time interval T13, and collecting the second concentration sensed by the second sensor; It is determined that the detection peak value of the second concentration collected within the T13 time interval is not less than 1.5*N11A, and the detection average value is greater than N11A, and it is determined that liquid hydrogen leakage occurs at the potential leakage source.

6. The hydrogen equipment leakage detection method according to claim 5, characterized in that: When it is determined that the first concentration increases from no greater than N1Z to no less than 1.5*N11A within the time interval T11, it is determined that liquid hydrogen leakage occurs at the potential leakage source.

7. A hydrogen equipment leak detection method, characterized in that: The hydrogen equipment leakage detection device according to any one of claims 2 to 4 comprises: Under the condition that the first power unit is started at a preset frequency, the first sensor is controlled to be in a first concentration detection mode, and a first concentration sensed by the first sensor is collected; Determining that the output value of the first concentration reaches N21A within a time interval T21, controlling the direction of the sensing surface of the second sensor to traverse multiple potential leakage sources located within a sensing area of ​​the second sensor, and staying at the location of each potential leakage source for a time interval T22, wherein within each of the T22 time intervals, controlling the second power unit to switch between starting and stopping, and collecting the second concentration sensed by the second sensor; It is determined that the average value of the second concentration collected in the startup and shutdown states in the T22 time interval in at least one direction of the second sensor is not lower than N22A and N22B, and it is preliminarily determined that the potential leakage source corresponding to the direction has leaked pressurized hydrogen.

8. The hydrogen equipment leakage detection method according to claim 7, characterized in that: Controlling the first sensor to switch to a first temperature detection mode, controlling the second sensor to switch to a second temperature detection mode, and controlling the sensing surface of the second sensor to remain facing a potential leakage source of gaseous hydrogen, shutting down the first power unit and the second power unit, and collecting first and second temperatures sensed by the first and second sensors, respectively; When the difference between the average temperature values ​​Tr21 and Tr22 of the first temperature and the second temperature sensed within the time interval T23 is not lower than the preset temperature threshold, it is determined that pressurized hydrogen leakage occurs in the potential leakage source corresponding to the direction.

9. A method for detecting leakage of hydrogen equipment, characterized in that: The hydrogen equipment leakage detection device according to any one of claims 2 to 4 comprises: Under the condition that the first power unit is started at a preset frequency, the first sensor is controlled to be in a first concentration detection mode, and a first concentration sensed by the first sensor is collected; Determining that the output value of the first concentration is not greater than N31A within a time interval T31, controlling the second sensor to rotate according to a preset angle, thereby sequentially changing the orientation of its sensing surface within the regions where multiple potential leakage sources are located, and when the sensing surface of the second sensor is oriented in a direction of one of the regions where multiple potential leakage sources are located, staying in that direction for a time period T32, and recording a fluctuation range of the output value of the second sensor in the second concentration detection mode within the time interval T32, thereby obtaining multiple fluctuation ranges; When it is determined that the maximum value of at least one of the fluctuation ranges is not less than N32Tmax and the minimum value is not less than N32Tmin, it is determined that a non-hydrogen medium leak occurs in the potential leakage source near the direction.

10. The hydrogen equipment leakage detection method according to claim 9, characterized in that: Also includes: Obtaining the direction of the side gas inlet of the second sensor within the time interval T32; It is determined that a potential leakage source near the side gas inlet of the second sensor has occurred non-hydrogen medium leakage.

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