Full-automatic PCT tester capable of switching temperature channels and method

Abstract

The invention relates to a full-automatic PCT tester capable of switching temperature channels and a method, the tester comprises a tester main body, the tester main body is provided with a test gas circuit, the test gas circuit comprises a hydrogen gas circuit, a pressure relief gas circuit, an exhaust gas circuit, a vacuum gas circuit and two sample chambers, the tester main body is internally provided with a shunt channel, the shunt channel is provided with a plurality of interfaces, and the interfaces are communicated with the test gas circuit; the hydrogen gas path, the pressure relief gas path, the vacuum gas path, the exhaust gas path and the sample chamber are correspondingly connected to the shunting channel one by one through interfaces; the heating furnace is used for accommodating the sample chamber; the water bath is used for accommodating another sample chamber; and the vacuum pump is connected to the vacuum gas path. The two sample chambers are located in the heating furnace and the water bath respectively, samples can be tested in any sample chamber, and due to the fact that the testing temperatures of the heating furnace and the water bath are different, the PCT tester has a wider testing temperature range, and the universality of the tester is improved.

Description

Technical Field

[0001] This application relates to the field of performance testing of solid hydrogen storage materials, and in particular to a fully automated PCT tester and method with switchable temperature channels. Background Technology

[0002] A PCT (Pressure-Concentration-Temperature) analyzer is a gas-solid reaction testing device used to determine the gas cyclic adsorption / desorption performance of metallic materials. This device studies and evaluates the hydrogen adsorption and desorption performance of hydrogen storage materials under different conditions by varying pressure, composition, and temperature. A fully automated program is designed to measure the gas adsorption, thermodynamic properties, cycling performance, and phase composition of samples. PCT (or PCI) stands for Pressure-Concentration-Temperature Measurement. These are isothermal measurements in which the sample temperature remains constant, and a defined gas fraction is introduced or desorbed from the sample. For each fraction, the sample and gas reach an equilibrium energy state determined by the gas pressure and sample temperature.

[0003] However, existing PCT testers have a narrow temperature range, which limits their testing capabilities and restricts their application. Summary of the Invention

[0004] Therefore, it is necessary to address the issue of the limited application range of the PCT tester.

[0005] On the one hand, a fully automatic PCT tester with switchable temperature channels is provided, including: The main body of the test instrument has a test gas path, which includes a hydrogen gas path, a depressurization gas path, an exhaust gas path, a vacuum gas path, and two sample chambers. The main body of the test instrument has a flow distribution channel with several interfaces. The hydrogen gas path, depressurization gas path, vacuum gas path, exhaust gas path, and sample chambers are connected to the flow distribution channel one by one through the interfaces. A heating furnace, which houses one of the sample rooms; A water bath is used to house another sample chamber. Vacuum pump, the vacuum pump is connected to the vacuum circuit.

[0006] In one embodiment, a pneumatic diaphragm valve is installed on the diversion channel, and the pneumatic diaphragm valve is configured with a corresponding interface, which controls the on / off state of the interface.

[0007] In one embodiment, a pneumatic diaphragm valve is installed on the diversion channel, and the pneumatic diaphragm valve is configured with a corresponding interface, which controls the on / off state of the interface.

[0008] In one embodiment, the main body of the tester also has a nitrogen gas path, which is connected to a drive valve island. The drive valve island is connected to a pneumatic diaphragm valve, and the pneumatic diaphragm valve is driven to work by nitrogen.

[0009] In one embodiment, the nitrogen gas path is split into a first branch and a second branch through a three-way connector. The first branch is connected to the drive valve island, and the second branch is connected to the test gas path.

[0010] In one embodiment, an adjustment switch is provided on the second branch.

[0011] In one embodiment, the diversion channel is connected to a buffer cavity.

[0012] In one embodiment, the buffer chamber includes a first buffer chamber and a second buffer chamber, wherein the cylinder volume in the first buffer chamber is greater than the cylinder volume in the second buffer chamber.

[0013] On the other hand, a PCT testing method is also provided, which uses the fully automated PCT tester described in the above embodiments. The steps of the method include: Depending on the required test temperature, the sample is placed into the sample chamber of the corresponding heating furnace or water bath. Control the opening and closing of the first buffer chamber according to the target pressure; Perform hydrogen absorption and emission tests on the samples; After the test is completed, the test gas path is emptied and then evacuated to a vacuum state. The second branch of the nitrogen gas path is opened, and nitrogen is introduced into the test gas path.

[0014] In one embodiment, controlling the on / off state of the first buffer chamber according to the target pressure includes: When the target pressure is not greater than the preset pressure value, the first buffer chamber is opened. When the target pressure exceeds the preset pressure value, the first buffer chamber is closed.

[0015] In one embodiment, the second branch of the nitrogen gas path is opened, and nitrogen is introduced into the test gas path, including: Based on the test gas path, adjust the switch to control the injection of nitrogen into the second branch at either the first or second pressure. The first pressure value is greater than the second pressure value.

[0016] The aforementioned fully automated PCT tester has two sample chambers located in a heating furnace and a water bath, respectively. Samples can be selected from either sample chamber for testing. Due to the different testing temperatures of the heating furnace and the water bath, the PCT tester has a wider testing temperature range, which facilitates the testing of more types of hydrogen storage materials, thereby improving the versatility of the tester.

[0017] The above testing method replaces the hydrogen environment in the test gas path with inert nitrogen after the test is completed. The crystal structure of the sample taken from the nitrogen environment will not be changed, which is convenient for subsequent recycling. At the same time, nitrogen is safer than hydrogen, and the test gas path is safer in a nitrogen environment. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of a PCT tester provided in an embodiment of this application.

[0019] Figure 2 This is a three-dimensional structural diagram of the internal structure of the tester body provided in an embodiment of this application.

[0020] Figure 3 This is a simplified schematic diagram of a test gas path provided in an embodiment of this application.

[0021] Figure 4 This is a partial structural diagram of the internal structure of the tester body provided in an embodiment of this application.

[0022] Figure 5 This is a front view of the interior of the tester body provided in an embodiment of this application.

[0023] Figure label: 1. Main body of the tester; 11. Nitrogen gas path; 111. First switching valve; 112. First filter; 113. First pressure sensor; 114. First regulating valve; 115. First three-way connector; 116. Second three-way connector; 117. Regulating switch; 12. Hydrogen gas path; 121. Second connector; 122. Second filter; 123. Second pressure sensor; 124. Second regulating valve; 125. Second check valve; 126. First flow restrictor; 131. Drive valve island; 132. Pneumatic diaphragm valve; 14. Pressure relief air path; 141. Third regulating valve; 15. Vacuum circuit; 151. Third check valve; 16. First buffer chamber; 161. First cylinder; 162. Low-pressure sensor; 163. Second switching valve; 164. Fourth three-way interface; 165. Fourth regulating valve; 166. Second flow limiting part; 17. Second buffer chamber; 171. Second cylinder; 18. First test module; 181. First sample chamber; 182. First connection channel; 19. Second test module; 191. Second sample chamber; 192. Second connection channel; 101. Diversion channel; 102. First pressure module; 103. Second pressure module; 2. Heating furnace; 3. Water bath; 4. Workbench; 5. Vacuum pump. Detailed Implementation

[0024] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0025] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0026] Furthermore, where the terms "first," "second," "third," and "fourth" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include at least one of that feature. In the description of this application, where the terms "multiple" or "several" appear, "multiple" means at least two, such as two, three, etc., and "several" means one or more, unless otherwise explicitly specified.

[0027] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0029] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0030] See Figure 1 As shown in the illustration, an embodiment of this application provides a fully automatic PCT tester with switchable temperature channels, comprising: a tester body 1, a heating furnace 2, a water bath 3, a worktable 4, and a vacuum pump 5. The tester body 1 has a built-in test gas path for hydrogen operation and testing. The test gas path has two sample chambers, each for holding a hydrogen storage material sample. The two sample chambers are respectively housed in the heating furnace 2 and the water bath 3. Different temperature adjustment methods for the heating furnace 2 and the water bath 3 result in different temperature thresholds. In a specific embodiment, a 1:1 mixture of ethylene glycol and water solution is used as the coolant in the water bath. The highest temperature achieved by the heating furnace 2 is higher than that achieved by the water bath 3. Simultaneously, the ethylene glycol and water coolant can meet the operating environment of -20℃, allowing the fully automatic PCT tester to achieve a wider temperature range. Depending on the required test temperature, the operator can place the hydrogen storage material sample into the sample chamber of the heating furnace 2 or the water bath 3 for testing. The workbench 4 serves as a supporting structure for the main body 1 of the testing instrument, raising its height. Although not shown in the figure, it can be understood that the workbench 4 can also serve as a supporting structure for the heating furnace 2, the water bath 3, and the vacuum pump 5.

[0031] In this scheme, combined with Figure 2-5As shown, the test gas path includes a hydrogen gas path 12, a depressurization gas path 14, a vacuum gas path 15, an exhaust gas path, and a test module. The main body 1 of the test instrument has a flow distribution channel 101 with several interfaces. The hydrogen gas path 12, depressurization gas path 14, vacuum gas path 15, exhaust gas path, and test module are connected to the flow distribution channel 101 one-to-one through these interfaces. The flow distribution channel 101 connects the various gas paths in the test gas path in parallel, allowing the on / off states of several gas paths (specifically, the number of several gas paths is less than the total number of gas paths in the test gas path) to control whether the corresponding functional components connected to each gas path work collaboratively. The test module contains a sample chamber; a heating furnace 2 houses one sample chamber, and a water bath 3 houses the other sample chamber.

[0032] Understandably, the test module includes, but is not limited to, the sample chamber, which is connected to the flow channel 101 during PCT testing. The test module also includes a calibration gas path, which is connected to the flow channel 101 before PCT testing. The volume of the sample chamber and other parts is determined by the calibration gas path and the calibration system connected to it, along with the software, to accurately calibrate the volume of each gas path before testing.

[0033] Vacuum pump 5 is connected to vacuum circuit 15. On one hand, vacuum pump 5 can evacuate the test gas circuit, and after evacuation, hydrogen can be added to ensure the hydrogen concentration in the test gas circuit, thereby ensuring detection accuracy. On the other hand, after the test is completed, the gas in the test gas circuit will be discharged because the pressure is higher than normal. However, after the test gas circuit returns to normal pressure, the gas discharge rate in the test gas circuit will decrease, and the gas in the test gas circuit may not be completely discharged, which will affect the results of the next sample test.

[0034] To control the simultaneous operation of several gas distribution paths, a pneumatic diaphragm valve 132 is installed on the distribution channel 101 in this design. The pneumatic diaphragm valve 132 has corresponding interface settings, and controls the opening and closing of these interfaces to allow gas in the distribution paths to flow into or out of the distribution channel 101. Specifically, the pneumatic diaphragm valve 132 is installed on corresponding interfaces, and can open and close the respective interfaces.

[0035] Furthermore, the main body 1 of the tester also has a nitrogen gas path 11, which is connected to a drive valve island 131. The drive valve island 131 is connected to a pneumatic diaphragm valve 132, and nitrogen is used as the driving gas to drive the pneumatic diaphragm valve 132. At the same time, the nitrogen gas path 11 is split into a first branch and a second branch through a three-way connector. The first branch is connected to the drive valve island 131, and the second branch is connected to the test gas path.

[0036] Specifically, the nitrogen gas path 11 has a main path and two branches connected to the main path. The main path is equipped with a first switching valve 111, a first filter 112, a first pressure sensor 113, and a first regulating valve 114. The main path is divided into two branches through a second three-way interface 116. The first branch is connected to the drive valve island 131, and the second branch is connected to the test gas path and to one of the interfaces of the diversion channel 101. Nitrogen is not only used as the driving gas for the pneumatic diaphragm valve 132, but it is also fed into the test gas path to replace hydrogen filling the test gas path. Nitrogen is an inert gas, which can effectively avoid the above problems compared to hydrogen, which may react with the pipeline (hydrogen embrittlement), cause unnecessary changes to the crystal structure of the sample taken from a hydrogen environment (requiring an additional dehydrogenation step during circulation, which is time-consuming and laborious), or cause human exposure to a hydrogen environment and potential danger. Compared to solutions that require different types of driving gases and encapsulation gases, and thus different gas supply channels, this solution uses a single nitrogen gas path 11, which effectively simplifies the structure.

[0037] More specifically, a regulating switch 117 is provided on the second branch. In one specific embodiment, the regulating switch 117 is a three-way ball valve, with its two inlets connected to the second branch and the main passage, respectively, and its outlet connected to one of the interfaces of the diversion channel 101. In this specific embodiment, the three-way ball valve can regulate the nitrogen pressure entering the test gas path. For example, the nitrogen pressure in the test gas path can be 0.6 MPa or 0.1 MPa, wherein the nitrogen pressure of 0.6 MPa is the purging pressure, used to expel hydrogen from the test gas path, so that the pressure inside the test gas path is 0.1 MPa. The nitrogen pressure of 0.1 MPa is the sealing pressure, and the sealing pressure of 0.1 MPa allows for easy removal of the sample from the quick connector after the test. The nitrogen input pressure is controlled by a three-way ball valve. Since sampling requires the introduction of a gas at the same pressure (usually hydrogen), and a significant pressure differential is required within the hydrogen gas path 12, it's difficult to precisely control the supply of a lower pressure gas at the sample location. For example, if the hydrogen pressure within the gas path is 10 MPa, it will be difficult to accurately control the supply of 0.1 MPa of hydrogen to the sample location. Furthermore, hydrogen is relatively reactive, and users do not want hydrogen to overflow from the sample chamber when removing the sample; therefore, it is necessary to ensure that the hydrogen pressure within the test gas path remains relatively low.

[0038] In some embodiments of this application, the hydrogen gas path 12 is sequentially provided with a second connector 121, a second filter 122, a second pressure sensor 123, a second regulating valve 124, a second one-way valve 125, and a first flow limiting part 126. The second connector 121 is used to connect to a hydrogen source. After the hydrogen enters the hydrogen gas path 12 from the second connector 121, it is filtered by the second filter 122. The second pressure sensor 123 is used to monitor the hydrogen pressure in the hydrogen gas path 12. After the hydrogen passes through the second one-way valve 125, the hydrogen is difficult to flow back. A second regulating valve 124 is also provided between the second one-way valve 125 and the second filter 122. The amount of hydrogen entering the second one-way valve 125 is controlled by the second pressure sensor 123 and the second regulating valve 124. The first flow limiting part 126 is used to slow down the flow rate of the hydrogen and prevent the excessively fast flow rate from impacting the pneumatic diaphragm valve 132. In this scheme, the first flow limiting part 126 is a narrow tube. The narrow tube is coiled into an O-shape, U-shape, circle or S-shape. By increasing the complexity of airflow, the resistance is increased, thereby slowing down the airflow velocity. The second regulating valve 124 (which limits the amount of hydrogen passing through per unit time) and the first flow limiting part 126 (which limits the flow rate of hydrogen) work together to reduce the flow rate of hydrogen, so as to more accurately control the amount of hydrogen entering the diversion channel 101.

[0039] Meanwhile, the pressure relief gas path 14 has a third regulating valve 141 and a plug. For example, the third regulating valve 141 is a needle valve. Firstly, during the gas path volume calibration test before PCT testing, compared to existing unloading valves, the unloading valve begins to slowly exhaust gas to the outside at a working pressure of 1 MPa. This slight leakage is coupled with the pressure drop caused by temperature. The volume change before and after the needle valve opens and closes is small, and the leakage rate is extremely low after closing, allowing for high-precision cavity volume calibration. Secondly, when the PCT tester is working normally, the needle valve is tightened to prevent any form of leakage in the test gas path. In emergency situations such as pressure control failure, it can be used as a pressure buffer port to regulate the pressure release flow rate and avoid potential personal safety hazards caused by direct pressure release to the plug. The vacuum path 15 is connected to the vacuum pump 5 to completely extract the gas in the test gas path. The vacuum path 15 is equipped with a one-way valve 151 to prevent external gas from flowing back into the test gas path through the vacuum path 15. The exhaust air path is connected to the outside to discharge the gas in the test air path. The exhaust air path has a fourth regulating valve 165 and a second flow limiting part 166. The function of the fourth regulating valve 165 and the second flow limiting part 166 is similar to that of the second regulating valve 124 and the first flow limiting part 126, and their structures are also similar, so as to reduce the amount of gas in the test air path and facilitate control.

[0040] Furthermore, the diversion channel 101 is connected to a buffer chamber. This buffer chamber includes a first buffer chamber 16 and a second buffer chamber 17. The first buffer chamber 16 includes a first cylinder 161, and the second buffer chamber 17 includes a second cylinder 171. The volume of the first cylinder 161 is larger than the volume of the second cylinder 171. For example, the calibrated volume of the first cylinder 161 is approximately 2100 ml, and the calibrated volume of the second cylinder 171 is approximately 15 ml. Because the external pressure is atmospheric, the internal pressure of the test gas path needs to be maintained slightly higher than atmospheric pressure to allow hydrogen to escape. Therefore, the pressure inside the test gas path is controlled at a minimum of 0.14 MPa. When the internal pressure is lower than 0.14 MPa, the pressure drops to zero the instant the vacuum pump 5 is turned on. Taking a volume ratio of 1:1 between the second cylinder 171 and the sample chamber as an example, if the sample hydrogen absorption is low, the first point pressure of the PCT will fall at 0.07 MPa. In many tests, the first pressure point of the PCT is at 0.001 MPa. Due to the excessively high control precision, it is difficult to control accurately in practice. If the test pressure is high, the first cylinder 161 is opened, connecting it to the test air circuit and expanding the volume from 15 ml to approximately 2100 ml. At this point, the pressure control is slow, and even with an intake increment of 0.001 MPa, it can be easily controlled.

[0041] In this design, the high and low temperature sample chambers within the test module are CNC machined, and their volume difference is measured to be 0.04 ml after high-precision volume calibration. Compensation is built into the PCT testing software, and manual testing allows for the removal of hydrogen and the introduction of nitrogen gas at a pressure slightly higher than atmospheric pressure. Therefore, the high and low temperature sample chambers can be switched to any test channel; simply setting the connected channel in the software allows for testing with the same precision without causing damage to quick-connect fittings due to high-voltage plugging / unplugging, incorrect hydrogen absorption by the sample, or oxygen intrusion.

[0042] In one specific embodiment, the PCT test method based on the fully automated PCT tester provided in the above embodiments includes the following steps: According to the required test temperature, the sample is placed into the sample chamber of the test module in the corresponding heating furnace 2 or water bath 3. Specifically, the temperature is adjusted by using heating furnace 2 or water bath 3 according to the required temperature range. The controllable temperature ranges of heating furnace 2 and water bath 3 are different, which allows the PCT tester to have a wider controllable range, thereby increasing the variety of hydrogen storage material samples that the PCT tester can test and improving its versatility.

[0043] Based on the target pressure, control the opening and closing of the first buffer chamber 16 or the second buffer chamber 17; wherein, the target pressure is the pressure required to be achieved in the test.

[0044] Perform hydrogen absorption and emission tests on the samples; After the test, the first buffer chamber 16 or the second buffer chamber 17 is emptied and restored to normal pressure. Then, the test gas path is evacuated to negative pressure by a vacuum pump. Finally, the second branch of the nitrogen gas path 11 is opened and nitrogen is sent into the test gas path.

[0045] In this scheme, the on / off state of the first buffer chamber 16 or the second buffer chamber 17 is controlled according to the target pressure, including: When the target pressure is not greater than the preset pressure value, the first buffer chamber 16 is opened and the second buffer chamber 17 is closed. When the target pressure is greater than the preset pressure value, the first buffer chamber 16 is closed and the second buffer chamber 17 is opened.

[0046] For example, the preset pressure value is 0.2 MPa. Specific control steps include: when the target pressure is ≤0.2 MPa, opening the large gas cylinder connects it to the gas storage chamber, expanding the volume from 15 ml to approximately 2100 ml. At this point, pressure control is slow, and even with an intake increment of 0.001 MPa, it can be easily controlled. During testing, the valve containing the large gas cylinder is closed, and the test gas path volume remains unchanged. If the next test pressure is expected to exceed 0.2 MPa, the large gas cylinder will no longer be connected during filling.

[0047] In another specific embodiment, during the test, the second buffer chamber 17 is in a normally open state, specifically: When the target pressure is not greater than the preset pressure value, the first buffer chamber 16 is opened and the second buffer chamber 17 is opened. When the target pressure is greater than the preset pressure value, the first buffer chamber 16 is closed and the second buffer chamber 17 is opened.

[0048] When the target pressure is not greater than the preset pressure value, the buffer space in the test gas path is expanded, so that the amount of gas that the large test gas path can accommodate is increased, and the pressure change in the test gas path is slow, which is convenient for control.

[0049] In this scheme, after the test is completed, the second branch of the nitrogen gas path 11 is opened, and nitrogen is supplied into the test gas path. This includes: adjusting switch 117 to control the injection of nitrogen into the second branch at a first pressure or a second pressure, depending on the condition of the test gas path. More specifically: When the test gas path is in an abnormal state (for example, the temperature exceeds 100% of the safety value, or the hydrogen concentration exceeds the safety value), the regulating switch 117 controls the injection of nitrogen into the second branch at a first pressure.

[0050] When the test gas circuit is in normal condition, the regulating switch 117 controls the injection of nitrogen gas into the second branch at the second pressure to achieve sealing.

[0051] The first pressure value is greater than the second pressure value. For example, the first pressure value is 0.6 MPa, and the second pressure value is 0.1 MPa. By injecting nitrogen at the first pressure, hydrogen in the test gas path is expelled. Then, nitrogen is injected at the second pressure to ensure that the nitrogen encapsulates the sample in the sample chamber. The sample's crystal structure remains unchanged in the nitrogen environment, ensuring the absence of hydrogen within the sample. This eliminates the need for a dehydrogenation step in subsequent use, saving time and improving efficiency. Furthermore, using nitrogen for purging offers better safety than hydrogen purging.

[0052] Understandably, the above test termination conditions can be either the test is completed normally or because the test gas path is in an abnormal state (for example, the temperature exceeds 100% of the safe value, or the hydrogen concentration exceeds the safe value).

[0053] Furthermore, the first buffer chamber 16 is connected to the exhaust air path via a fourth three-way connector 164. A low-pressure sensor 162 and a second switching valve 163 are located between the first cylinder 161 and the exhaust air path. The fourth three-way connector 164 is positioned near the outlet of the exhaust air path. The outlet, fourth regulating valve 165, and second flow restrictor 166 are sequentially arranged on the exhaust air path. The fourth three-way connector 164 is located between the outlet and the fourth regulating valve 165. The low-pressure sensor 162 has a small range. To prevent high pressure damage to the low-pressure sensor 162 in case of accidental damage, the second switching valve 163 can be manually opened to quickly and manually release a large amount of hydrogen gas from the gas path in the first cylinder 161 connected to the exhaust air path via the first buffer chamber 16, ensuring the safe use of the low-pressure sensor 162. In addition, because the first cylinder 161 is too large, when the pressure is below 0.2MPa during venting, venting will become very difficult and the venting process will be very slow. Since the first buffer chamber 16 is connected to the venting air passage, the gas can be quickly vented to near normal pressure, and then the residual gas can be discharged by the vacuum pump 5, which greatly improves the efficiency and safety of venting the large steel cylinder.

[0054] Furthermore, the diversion channel 101 is also connected to a first pressure module 102 and a second pressure module 103. The first pressure module 102 is a high-pressure sensor (large-range pressure sensor), and the second pressure module 103 is a low-pressure sensor (small-range pressure sensor). The connection of the low-pressure sensor to the diversion channel 101 is controlled according to the required test pressure. In this scheme, the hydrogen storage capacity change rate and pressure are used to determine the test termination. Based on the pressure value and the hydrogen storage capacity change rate, it is determined whether the hydrogen storage material sample is in a saturated state. The hydrogen storage capacity change rate is calculated comprehensively based on temperature, pressure, volume, and time. Compared to existing methods that determine test termination based on time, for materials with different hydrogen storage capacities, some materials may reach saturation in 200 seconds, while others may take 1000 seconds. This results in different testing times required for different hydrogen storage material samples, necessitating setting the time according to the material type, which is time-consuming, labor-intensive, and prone to errors in estimating the saturation time, leading to biased test results. Using the hydrogen storage capacity change rate is a more accurate method.

[0055] In this scheme, the diversion channel 101 includes a main pipe and several branch pipes connected in parallel to the main pipe. Each branch pipe has an interface. There are 11 branch pipes, and each interface is connected one-to-one to the hydrogen gas path 12, the depressurization gas path 14, the vacuum gas path 15, the exhaust gas path, the second branch of the nitrogen gas path 11, the first pressure module 102, the second pressure module 103, the first buffer chamber 16, the second buffer chamber 17, the first test module 18, and the second test module 19. Pneumatic diaphragm valves 132 are installed on the interfaces of the gas path 12, vacuum path 15, exhaust air path, the second branch of nitrogen path 11, the second pressure module 103, the first buffer chamber 16, the second buffer chamber 17, the first test module 18, and the second test module 19, ensuring that the pressure relief gas path 14 and the first pressure module 102 are always in a normally open state. The pressure relief gas path 14 is used to ensure that gas in the diversion channel 101 can be quickly discharged in an emergency where pressure control fails. The first pressure module 102 is a high-pressure sensor that can monitor the pressure in the diversion channel 101 at any time.

[0056] In this solution, the test gas path is equipped with a hydrogen concentration detector and a temperature detector. The PCT tester also features an alarm. The alarm is triggered based on the detection results from the hydrogen concentration and temperature detectors. For each sample, the sample and gas reach an equilibrium energy state, determined by the gas pressure and sample temperature. Specifically, when the temperature exceeds 80% but not 100% of the safety value, the alarm is triggered, and the software indicates a general alarm level. When the temperature exceeds 100% of the safety value, or the hydrogen concentration exceeds the safety value, the program automatically and safely stops the current test program, closes all valves, switches to the purging program, triggers the alarm again, the software indicates an emergency alarm level, and the test gas path is automatically shut off. This truly achieves fully automated, unattended, and safe testing. The tester has a reasonable structure, high stability, reliability, and durability; it is easy to operate, performs well, and is easy to maintain and repair.

[0057] like Figure 3 As shown, branch pipes are symmetrically arranged on both sides of the main pipe, with the branch pipes on both sides symmetrically arranged with the axis of the main pipe as the center line. A branch pipe is also located at the top of the main pipe. At least the first pressure module 102 and the second pressure module 103 are located on the symmetrical branch pipe interfaces, as are the first buffer chamber 16 and the second buffer chamber 17. The first test module 18 and the second test module 19 are also located on the symmetrical branch pipe interfaces. Since there are many interfaces on the diversion channel 101, which can easily cause confusion, the parts with the same or similar functions are located on the symmetrical branch pipe interfaces for easy identification during maintenance. In addition, the depressurization air path 14, the vacuum air path 15, and the exhaust air path are located on the branch pipe on the same side of the main pipe to facilitate the subsequent recovery and collection of gas.

[0058] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A fully automatic PCT tester with switchable temperature channels, characterized in that, include: The main body of the test instrument (1) has a test gas path, which includes a hydrogen gas path (12), a depressurization gas path (14), a vacuum gas path (15), an exhaust gas path, and a sample chamber. The main body of the test instrument (1) has a diversion channel (101), which is provided with several interfaces. The hydrogen gas path (12), the depressurization gas path (14), the vacuum gas path (15), the exhaust gas path, and the sample chamber are connected to the diversion channel (101) one by one through the interfaces. A heating furnace (2), wherein one of the sample chambers is housed in the heating furnace (2); Water bath (3), which houses another sample chamber; Vacuum pump (5), which is connected to the vacuum circuit (15).

2. The fully automatic PCT tester according to claim 1, characterized in that, A pneumatic diaphragm valve (132) is installed on the diversion channel (101). The pneumatic diaphragm valve (132) is set corresponding to the interface and controls the opening and closing of the interface.

3. The fully automatic PCT tester according to claim 2, characterized in that, The main body (1) of the tester also has a nitrogen gas path (11), which is connected to the drive valve island (131). The drive valve island (131) is connected to the pneumatic diaphragm valve (132), and the pneumatic diaphragm valve (132) is driven to work by nitrogen.

4. The fully automatic PCT tester according to claim 3, characterized in that, The nitrogen gas path (11) is divided into a first branch and a second branch through a three-way connector. The first branch is connected to the drive valve island (131), and the second branch is connected to the test gas path.

5. The fully automatic PCT tester according to claim 4, characterized in that, An adjustment switch (117) is provided on the second branch.

6. The fully automatic PCT tester according to any one of claims 1-5, characterized in that, The diversion channel (101) is connected to a buffer cavity.

7. The fully automatic PCT tester according to claim 6, characterized in that, The buffer chamber includes a first buffer chamber (16) and a second buffer chamber (17), wherein the cylinder volume in the first buffer chamber (16) is greater than the cylinder volume in the second buffer chamber (17).

8. A PCT test method, characterized in that, Using the fully automated PCT tester according to any one of claims 1-7, the method comprises the following steps: According to the test temperature requirements, the sample is placed into the sample chamber of the corresponding heating furnace (2) or water bath (3); Control the opening and closing of the first buffer chamber (16) according to the target pressure; Perform hydrogen absorption and emission tests on the samples; After the test is completed, the test gas path is emptied and then evacuated to enter a vacuum state. The second branch of the nitrogen gas path (11) is opened, and nitrogen is sent into the test gas path.

9. The PCT test method according to claim 8, characterized in that, The control of the opening and closing of the first buffer chamber (16) according to the target pressure includes: When the target pressure is not greater than the preset pressure value, the first buffer chamber (16) is opened. When the target pressure is greater than the preset pressure value, the first buffer chamber (16) is closed.

10. The PCT test method according to claim 9, characterized in that, The second branch of the nitrogen gas path (11) is opened, and nitrogen is introduced into the test gas path, including: According to the test gas path, adjust the switch (117) to control the injection of nitrogen into the second branch at the first pressure or the second pressure; The first pressure value is greater than the second pressure value.

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