阅读说明：本技术 一种储氢合金pct曲线测试装置及方法 (Hydrogen storage alloy PCT curve testing device and method ) 是由 孙国安 马士恒 张骞 韩昊学 刘学武 李兆辉 王兴国 于 2019-10-30 设计创作，主要内容包括：本发明属于材料性能检测技术领域,涉及一种储氢合金PCT曲线测试装置及方法,包括样品室、气体管路和数据采集系统。主管道上设有样品室和压力传感器,样品室的法兰开螺纹孔,连接与氢气出入口分开布置的k型热电偶,样品室外部通过螺纹与加热装置和冷却装置进行连接。主管道的一端分别通过节流阀和电磁阀与氢气瓶和氦气瓶连接；另一端通过节流阀和电磁阀分别与真空计和大气连接,真空计与真空泵连接；压力传感器与主管道直接连接。本发明能快速加热与降低样品室的内部温度、并准确进行测量,从而节省储氢合金活化所需时间,整套装置测试效率高、测试准确、结构简单、操作方便、安全可靠。(The invention belongs to the technical field of material performance detection, and relates to a hydrogen storage alloy PCT curve testing device and a method. The main pipeline is provided with a sample chamber and a pressure sensor, a flange of the sample chamber is provided with a threaded hole and is connected with a k-type thermocouple separately arranged with a hydrogen inlet and a hydrogen outlet, and the outside of the sample chamber is connected with a heating device and a cooling device through threads. One end of the main pipeline is respectively connected with a hydrogen cylinder and a helium cylinder through a throttle valve and an electromagnetic valve; the other end is respectively connected with a vacuum gauge and the atmosphere through a throttle valve and an electromagnetic valve, and the vacuum gauge is connected with a vacuum pump; the pressure sensor is directly connected with the main pipeline. The invention can rapidly heat and reduce the internal temperature of the sample chamber and accurately measure, thereby saving the time required by activation of the hydrogen storage alloy, and the whole set of device has high testing efficiency, accurate test, simple structure, convenient operation, safety and reliability.)

1. A hydrogen storage alloy PCT curve testing device is characterized by comprising a sample chamber (3), a gas pipeline and a data acquisition system; the gas pipeline comprises a main pipeline and branch pipelines; the two ends of the main pipeline are respectively divided into two branches, one end of the main pipeline is a hydrogen branch and a helium branch which are respectively connected with the hydrogen cylinder (1) and the helium cylinder (2) through a throttle valve I (9), a solenoid valve I (12) and a throttle valve II (10) and a solenoid valve II (13), the throttle valve I (9) is close to the end of the hydrogen cylinder (1), and the throttle valve II (10) is close to the end of the helium cylinder (2); the other end of the main pipeline is an atmosphere branch and a vacuum branch which are respectively connected with atmosphere and a vacuum gauge (7) through an electromagnetic valve IX (20), a pressure reducing valve (22), a throttle valve III (11), an electromagnetic valve VII (18) and an electromagnetic valve VIII (19), the pressure reducing valve (22) is close to the atmosphere end, the electromagnetic valve VIII (19) is close to the vacuum gauge (7) end, the electromagnetic valve VII (18) is positioned between the throttle valve III (11) and the electromagnetic valve VIII (19), and the vacuum gauge (7) is connected with a vacuum pump (8); the middle part of the main pipeline is also provided with three branches which are respectively a sample branch, a hydrogen pressurization branch and a system pipeline volume calibration branch, the sample branch is connected with the sample chamber (3) through a solenoid valve III (14) and a solenoid valve IV (15), the solenoid valve IV (15) is close to the sample chamber (3), the hydrogen pressurization branch is connected with the small gas storage bottle (5) through a solenoid valve V (16), and the system pipeline volume calibration branch is connected with the large gas storage bottle (6) through a solenoid valve VI (17); a temperature control device (4) is arranged outside the sample chamber (3), a temperature sensor (23) is arranged on the large gas storage bottle (6), a pressure sensor (21) is arranged on the main pipeline, and the pressure sensor (21) is positioned between the hydrogen branch and the sample branch as well as between the helium branch and the sample branch;

the data acquisition system comprises a computer (24) and a data acquisition unit (25), wherein the data acquisition unit (25) is connected with the computer (24); the electromagnetic valve I (12), the electromagnetic valve II (13), the electromagnetic valve III (14), the electromagnetic valve IV (15), the electromagnetic valve V (16), the electromagnetic valve VI (17), the electromagnetic valve VII (18), the electromagnetic valve VIII (19), the electromagnetic valve IX (20), the pressure sensor (21) and the temperature sensor (23) are all connected with a data acquisition unit (25); the data acquisition unit (25) acquires environmental temperature, sample chamber temperature and system pressure data, and the computer (24) calculates a hydrogen storage alloy PCT curve according to the acquired data and a gas state equation;

the sample chamber (3) comprises a k-type thermocouple (28), a flange (29) and a stainless steel alloy pipe (32); the top end of the stainless steel alloy pipe (32) is open, the upper end surface of the stainless steel alloy pipe is provided with a slot, and a sealing ring (31) is arranged in the slot; the flange (29) is arranged at the top end of the stainless steel alloy pipe (32) and is screwed down through bolts and nuts (30) to realize sealing; the flange (29) is provided with two through holes, one through hole is welded with a pipeline as a hydrogen inlet and outlet (26), a filter (27) is arranged at the bottom of the hydrogen inlet and outlet (26), the hydrogen inlet and outlet (26) is connected with a gas pipeline of a sample branch through an electromagnetic valve IV (15), the other through hole is used for mounting a k-type thermocouple (28), a hydrogen storage alloy (33) is arranged in a stainless steel alloy pipe (32), the bottom of the k-type thermocouple (28) is inserted into the hydrogen storage alloy (33), and the k-type thermocouple (28) is connected with a data collector (25); the outer surface of the stainless steel alloy pipe (32) is provided with external threads, and is assembled with the temperature control device (4) through threaded connection;

the temperature control device (4) comprises a heating device and a cooling device; the heating device comprises an electric heating rod (34), a sleeve I (35) and a base (36); the inner wall of the sleeve I (35) is an internal thread, and the sleeve I (35) is welded on the base (36); the electric heating rod (34) is arranged in the wall body of the sleeve I (35) and is connected with the data acquisition system through the temperature controller; the cooling device comprises a sleeve II (39), a water inlet (37) is formed in the lower portion of the sleeve II (39), a water outlet (38) is formed in the upper portion of the sleeve II (39), and the inner wall of the sleeve II (39) is an internal thread; and according to the heating or cooling requirement, the sleeve I (35) or the sleeve II (39) is connected with the stainless steel alloy pipe (32) through threads.

2. The apparatus for testing PCT curve of hydrogen occluding alloy as recited in claim 1, wherein said stainless steel alloy tube (32) is 304 stainless steel and is cylindrical in shape.

3. PCT curve testing device for hydrogen storage alloys according to claim 1 or 2, characterized in that said small gas cylinder (5) has a volume of 50-100ml for hydrogen pressurization; the volume of the large gas storage bottle (6) is 100-200ml, and the large gas storage bottle is used for calibrating the volume of a system pipeline.

4. A method for obtaining a hydrogen storage alloy PCT curve using the hydrogen storage alloy PCT curve testing apparatus as defined in claims 1 to 3, comprising the steps of:

step 1, calibrating the volume of a system: opening the hydrogen cylinder (1), and raising the pressure in the large gas storage cylinder (6) to 2-3 MPa; standing until the pressure and temperature in the large gas storage bottle (6) do not change any more, and recording the pressure P at the moment₀And temperature T₀(ii) a Closing the electromagnetic valve VI (17), and starting the vacuum pump (8) for vacuumizing; then opening the electromagnetic valve VI (17), standing until the pressure and the temperature are not changed, and the pressure and the temperature of the stabilized large gas storage bottle (6) are P₁And T₁The system volume V is calculated as follows:

P₀V₀ρ₀＝P₁(V₀+V)ρ₁

in the formula: v_o: the volume of a large gas cylinder; v: the system volume; rho₀：P₀And T₀Density of hydrogen under conditions; rho₁：P₁And T₁Density of hydrogen under conditions;

step 2, hydrogen absorption test:

before testing, opening all manual valves including a throttle valve I (9), a throttle valve II (10), a throttle valve III (11) and a pressure reducing valve (22), ensuring all electromagnetic valves to be in a closed state, and after testing is started, controlling the opening and closing of the electromagnetic valves by a computer (24) to finish all testing; wherein, the solenoid valve IV (15) is kept normally open in the hydrogen absorption test, and the solenoid valve III (14) is kept normally open in the hydrogen discharge test; the method comprises the following specific steps:

s1, loading a hydrogen storage alloy (33) into a sample chamber (3), opening a solenoid valve III (14), a solenoid valve V (16), a solenoid valve VI (17), a solenoid valve VII (18) and a solenoid valve VIII (19), starting a vacuum pump (8) for vacuumizing, and closing the solenoid valve VII (18) and the solenoid valve VIII (19) after the vacuumizing is finished;

s2, opening a solenoid valve II (13), filling helium into the system, closing the solenoid valve II (13) after scavenging is finished, opening a solenoid valve VII (18) and a solenoid valve VIII (19), starting a vacuum pump (8) for vacuumizing, and then closing a solenoid valve V (16), a solenoid valve VI (17), a solenoid valve VII (18) and a solenoid valve VIII (19);

s3, installing a heating device in a temperature control device (4) according to the temperature and hydrogen pressure required by activation of the hydrogen storage alloy, heating the temperature to a value required by activation of the hydrogen storage alloy, opening a solenoid valve I (12), filling hydrogen into the system until the pressure reaches the pressure required by activation of the hydrogen storage alloy, closing the solenoid valve I (12), preserving the heat for 30-40min, removing the heating device, installing a cooling device in the temperature control device (4), cooling the temperature to room temperature, opening a solenoid valve IX (20), releasing the hydrogen, then opening a solenoid valve VII (18) and a solenoid valve VIII (19), starting a vacuum pump (8), vacuumizing, completing an activation process in this way, and repeating the process until the hydrogen storage alloy is completely activated;

s4, after the alloy is completely activated, reinstalling a heating device, heating to the temperature required by activation of the hydrogen storage alloy, opening the electromagnetic valve VII (18) and the electromagnetic valve VIII (19), starting the vacuum pump (8), and vacuumizing to complete alloy dehydrogenation;

s5, heating by a heating device, setting the temperature to an experimental temperature, opening a solenoid valve I (12) after the temperature value required by the experiment in the sample chamber (3) is reached, closing other solenoid valves, introducing hydrogen into the system, closing the solenoid valve I (12) after the pressure of the system reaches a set hydrogen absorption pressure value, collecting the ambient temperature, the temperature of the sample chamber and the system pressure by a computer (24) and a data collector (25), opening a solenoid valve III (14), closing the solenoid valve III (14) after the pressure of the system is stable, and collecting the ambient temperature, the temperature of the sample chamber and the system pressure by the computer (24) and the data collector (25); repeating the operation, calculating the hydrogen absorption amount of each hydrogen charging by the computer (24) according to a gas state equation, and establishing a coordinate system by taking the ratio H/W of hydrogen atoms to material atoms as a horizontal coordinate and the hydrogen equilibrium pressure as a vertical coordinate to obtain a hydrogen absorption PCT curve;

wherein: the gas state equation isn is the amount of hydrogen material, P is the system pressure, V is the system volume, Z (P, T) is the actual correction parameter of the gas state equation, R is the gas molar constant, T is the thermodynamic temperature;

step 3, hydrogen discharge test:

the hydrogen discharge test principle is the same as the hydrogen absorption test, and the hydrogen discharge test is started under the state after the step 2 is completed; the method comprises the following specific steps:

s1, a computer (24) and a data collector (25) collect the current environment temperature, the sample chamber temperature and the system pressure;

s2, closing the electromagnetic valve IV (15), opening the electromagnetic valve VII (18) and the electromagnetic valve VIII (19), starting the vacuum pump (8) to vacuumize, wherein the vacuum degree reaches 0.01-0.05 Pa;

s3, opening an electromagnetic valve IV (15), after the pressure of the system is stabilized to a set hydrogen discharge pressure value, collecting the ambient temperature, the temperature of a sample chamber and the pressure of the system by a computer (24) and a data collector (25), and then closing the electromagnetic valve IV (15); repeating the above operations, the computer (24) calculates the hydrogen release amount in each hydrogen release according to the gas state equation, and establishes a coordinate system by taking the ratio H/W of the hydrogen atoms to the material atoms as a horizontal coordinate and the hydrogen equilibrium pressure as a vertical coordinate to obtain the hydrogen release PCT curve.

Technical Field

The invention belongs to the technical field of material performance detection, and particularly relates to a hydrogen storage alloy PCT curve testing device and method.

Background

The main energy in the world is fossil fuel such as coal, petroleum and natural gas, and the defects of combustion of the fossil fuel as an energy supply medium have been proposed for many years, on one hand, the storage amount of the fossil fuel is limited and the fossil fuel is a non-renewable resource; on the other hand, the global ecological environment continues to deteriorate as fossil fuels are burned for a long period of time. In order for human sustainable development, new energy sources must be actively developed while saving energy.

Hydrogen energy is a clean, green, wide and high-energy-density secondary energy, is abundant in reserves, can be recycled, and is considered as an important bridge for connecting fossil energy and renewable energy. With the vigorous development of hydrogen energy systems, efficient and safe hydrogen storage and delivery is still an important issue in the development of hydrogen energy systems. The hydrogen storage alloy has good development prospect due to large volume hydrogen storage density, safe atomic hydrogen storage mode, reusability, mature preparation technology and process and the like. The development of low-cost and high-performance hydrogen storage materials is the key direction of hydrogen storage research. The PCT curve is the most important parameter for evaluating the performance of the hydrogen storage alloy, and the hydrogen absorption quantity, the platform pressure, the hysteresis factor, the platform slope, the reaction enthalpy, the reaction entropy and the like of the hydrogen storage alloy can be obtained from the PCT curve, so that the method has important significance for the measurement and development of the performance of the hydrogen storage alloy.

The current PCT curve testing device for hydrogen storage alloy has many disadvantages, such as: (1) the manual testing device has complicated operation steps and is easy to have errors, the operation of the manual valve is easy to damage due to the force problem, and data measured in the experimental process needs to be observed and recorded by an experimenter, so that the testing efficiency is low, the testing precision and the objectivity are influenced, and a large human error exists; (2) most of the existing devices for testing the alloy performance can not accurately measure the internal temperature of the sample chamber, and an effective method for accurately measuring the internal temperature of the sample chamber is to place a temperature sensor in the sample chamber and simultaneously to easily calibrate the volume of the system; (3) the temperature of the sample chamber needs to be controlled within a certain range quickly and conveniently, and the sample chamber is placed in a constant temperature box in the conventional method, but the temperature rising and cooling speed is limited, so that the accuracy of experimental data is seriously influenced. Therefore, the method reduces the test period and improves the test efficiency under the condition of meeting the temperature control requirement, and is also the key content of the design of the hydrogen storage alloy PCT curve test device.

Disclosure of Invention

In order to make up the defects of the prior art, the invention aims to provide the device and the method for testing the PCT curve of the hydrogen storage alloy, which are convenient for system volume calibration, can accurately measure and control the temperature of the sample chamber, are convenient to operate, and are safe and reliable.

The invention adopts the following technical scheme:

a hydrogen storage alloy PCT curve testing device comprises a sample chamber 3, a gas pipeline and a data acquisition system; the gas pipeline comprises a main pipeline and branch pipelines; the two ends of the main pipeline are respectively divided into two branches, one end of the main pipeline is a hydrogen branch and a helium branch, and the hydrogen branch and the helium branch are respectively connected with a hydrogen cylinder 1 and a helium cylinder 2 through a throttle valve I9, a solenoid valve I12, a throttle valve II 10 and a solenoid valve II 13, wherein the throttle valve I9 is close to the end of the hydrogen cylinder 1, and the throttle valve II 10 is close to the end of the helium cylinder 2; the other end of the main pipeline is an atmosphere branch and a vacuum branch which are respectively connected with atmosphere and a vacuum gauge 7 through a solenoid valve IX 20, a pressure reducing valve 22, a throttle valve III 11, a solenoid valve VII 18 and a solenoid valve VIII 19, wherein the pressure reducing valve 22 is close to the atmosphere end, the solenoid valve VIII 19 is close to the vacuum gauge 7 end, the solenoid valve VII 18 is positioned between the throttle valve III 11 and the solenoid valve VIII 19, and the vacuum gauge 7 is connected with a vacuum pump 8; the middle part of the main pipeline is also provided with three branches which are a sample branch, a hydrogen pressurization branch and a system pipeline volume calibration branch respectively, the sample branch is connected with the sample chamber 3 through a solenoid valve III 14 and a solenoid valve IV 15, the solenoid valve IV 15 is close to the sample chamber 3, the hydrogen pressurization branch is connected with the small gas storage bottle 5 through a solenoid valve V16, and the system pipeline volume calibration branch is connected with the large gas storage bottle 6 through a solenoid valve VI 17; the temperature control device 4 is arranged outside the sample chamber 3, the temperature sensor 23 is arranged on the large gas storage bottle 6, the pressure sensor 21 is arranged on the main pipeline, and the pressure sensor 21 is positioned between the hydrogen branch and the helium branch and the sample branch.

The data acquisition system comprises a computer 24 and a data acquisition unit 25, wherein the data acquisition unit 25 is connected with the computer 24; the electromagnetic valve I12, the electromagnetic valve II 13, the electromagnetic valve III 14, the electromagnetic valve IV 15, the electromagnetic valve V16, the electromagnetic valve VI 17, the electromagnetic valve VII 18, the electromagnetic valve VIII 19, the electromagnetic valve IX 20, the pressure sensor 21 and the temperature sensor 23 are all connected with a data acquisition unit 25; the data collector 25 collects the environmental temperature, the sample chamber temperature and the system pressure data, and the computer 24 calculates the hydrogen storage alloy PCT curve according to the collected data and the gas state equation.

The sample chamber 3 comprises a k-type thermocouple 28, a flange 29 and a stainless steel alloy pipe 32; the top end of the stainless steel alloy pipe 32 is open, the upper end surface of the stainless steel alloy pipe is provided with a slot, and a sealing ring 31 is arranged in the slot; the flange 29 is arranged at the top end of the stainless steel alloy pipe 32 and is screwed up through bolts and nuts 30 to realize sealing; the flange 29 is provided with two through holes, one of the through holes is welded with a pipeline as a hydrogen inlet 26, the bottom of the hydrogen inlet 26 is provided with a filter 27, the hydrogen inlet 26 is connected with a gas pipeline of a sample branch through an electromagnetic valve IV 15, the other through hole is used for mounting a k-type thermocouple 28, a hydrogen storage alloy 33 is arranged in a stainless steel alloy pipe 32, the bottom of the k-type thermocouple 28 is inserted into the hydrogen storage alloy 33, and the k-type thermocouple 28 is connected with a data collector 25; the outer surface of the stainless steel alloy pipe 32 is an external thread and is assembled with the temperature control device 4 through threaded connection.

The temperature control device 4 comprises a heating device and a cooling device; the heating device comprises an electric heating rod 34, a sleeve I35 and a base 36; the inner wall of the sleeve I35 is an internal thread, and the sleeve I35 is welded on the base 36; the electric heating rod 34 is arranged in the wall body of the sleeve I35 and is connected with the data acquisition system through a temperature controller; the cooling device comprises a sleeve II 39, a water inlet 37 is formed in the lower portion of the sleeve II 39, a water outlet 38 is formed in the upper portion of the sleeve II 39, and the inner wall of the sleeve II 39 is an internal thread; and according to the heating or cooling requirement, the sleeve I35 or the sleeve II 39 is connected with the stainless steel alloy pipe 32 through threads.

Further, the stainless alloy tube 32 is made of 304 stainless steel, and is cylindrical.

Furthermore, the small gas cylinder 5 has a volume of 50-100ml and is used for hydrogen pressurization.

Further, the volume of the large gas storage bottle 6 is 100-200ml, and the large gas storage bottle is used for calibrating the volume of a system pipeline.

The hydrogen storage alloy PCT curve is obtained by using a hydrogen storage alloy PCT curve testing device, and the method comprises the following steps:

step 1, calibrating the volume of a system: opening the hydrogen cylinder 1, and raising the pressure in the large gas storage cylinder 6 to 2-3 MPa; standing until the pressure and temperature in the large gas storage bottle 6 do not change any more, and recording the pressure P at the moment₀And temperature T₀(ii) a Closing the electromagnetic valve VI 17, and starting the vacuum pump 8 to vacuumize; then the electromagnetic valve VI 17 is opened, the mixture is kept stand until the pressure and the temperature are not changed, and the pressure and the temperature of the stabilized large gas storage bottle 6 are P₁And T₁The system volume V is calculated as follows:

P₀V₀ρ₀＝P₁(V₀+V)ρ₁

in the formula: v_o: the volume of a large gas cylinder; v: the system volume; rho₀：P₀And T₀Density of hydrogen under conditions; rho₁：P₁And T₁Density of hydrogen under conditions.

Step 2, hydrogen absorption test:

before testing, all manual valves including a throttle valve I9, a throttle valve II 10, a throttle valve III 11 and a pressure reducing valve 22 are opened, all electromagnetic valves are ensured to be in a closed state, and after the testing is started, a computer 24 controls the opening and closing of the electromagnetic valves to complete all testing; wherein, the solenoid valve IV 15 is kept normally open in the hydrogen absorption test, and the solenoid valve III 14 is kept normally open in the hydrogen discharge test; the method comprises the following specific steps:

s1, loading hydrogen storage alloy 33 into a sample chamber 3, opening a solenoid valve III 14, a solenoid valve V16, a solenoid valve VI 17, a solenoid valve VII 18 and a solenoid valve VIII 19, starting a vacuum pump 8 for vacuumizing, and closing the solenoid valve VII 18 and the solenoid valve VIII 19 after the vacuumizing is completed.

S2, opening the electromagnetic valve II 13, filling helium into the system, closing the electromagnetic valve II 13 after scavenging is finished, opening the electromagnetic valve VII 18 and the electromagnetic valve VIII 19, starting the vacuum pump 8 for vacuumizing, and then closing the electromagnetic valve V16, the electromagnetic valve VI 17, the electromagnetic valve VII 18 and the electromagnetic valve VIII 19.

S3, according to the temperature and hydrogen pressure required by activation of the hydrogen storage alloy, installing a heating device in a temperature control device 4, heating the temperature to the value required by activation of the hydrogen storage alloy, opening a solenoid valve I12, filling hydrogen into the system until the pressure reaches the pressure required by activation of the hydrogen storage alloy, closing the solenoid valve I12, preserving the heat for 30-40min, removing the heating device, installing a cooling device in the temperature control device 4, cooling the temperature to room temperature, opening a solenoid valve IX 20, releasing the hydrogen, then opening a solenoid valve VII 18 and a solenoid valve VIII 19, starting a vacuum pump 8, vacuumizing, completing the activation process once, and repeating the process until the hydrogen storage alloy is completely activated.

S4, after the alloy is completely activated, reinstalling a heating device, heating to the temperature required by activation of the hydrogen storage alloy, opening the electromagnetic valve VII 18 and the electromagnetic valve VIII 19, starting the vacuum pump 8, and vacuumizing to complete alloy dehydrogenation;

s5, heating by a heating device, setting the temperature to an experimental temperature, opening an electromagnetic valve I12 after the temperature value required by the experiment in the sample chamber 3 is reached, closing other electromagnetic valves, introducing hydrogen into the system, closing the electromagnetic valve I12 after the pressure of the system reaches a set hydrogen absorption pressure value, collecting the ambient temperature, the temperature of the sample chamber and the system pressure by a computer 24 and a data collector 25, opening an electromagnetic valve III 14, closing the electromagnetic valve III 14 after the pressure of the system is stable, and collecting the ambient temperature, the temperature of the sample chamber and the system pressure by the computer 24 and the data collector 25; repeating the above operations, the computer 24 calculates the hydrogen absorption amount during each hydrogen charging according to the gas state equation, and establishes a coordinate system by taking the ratio H/W of the hydrogen atoms to the material atoms as a horizontal coordinate and the hydrogen equilibrium pressure as a vertical coordinate to obtain a hydrogen absorption PCT curve;

wherein: the gas state equation isn is the amount of hydrogen material, P is the system pressure, V is the system volume, Z (P, T) is the actual correction parameter of the gas state equation, R is the gas molar constant, T is the thermodynamic temperature;

step 3, hydrogen discharge test:

the hydrogen discharge test principle is the same as the hydrogen absorption test, and the hydrogen discharge test is started under the state after the step 2 is completed; the method comprises the following specific steps:

s1, a computer 24 and a data acquisition device 25 acquire the current environment temperature, the sample chamber temperature and the system pressure;

s2, closing the electromagnetic valve IV 15, opening the electromagnetic valve VII 18 and the electromagnetic valve VIII 19, and starting the vacuum pump 8 to vacuumize until the vacuum degree reaches 0.01-0.05 Pa.

S3, opening the electromagnetic valve IV 15, after the system pressure is stabilized to a set hydrogen discharge pressure value, collecting the environment temperature, the sample chamber temperature and the system pressure by the computer 24 and the data collector 25, and then closing the electromagnetic valve IV 15; repeating the above operations, the computer 24 calculates the hydrogen release amount in each hydrogen release according to the gas state equation, and establishes a coordinate system by taking the ratio H/W of the hydrogen atoms to the material atoms as the abscissa and the hydrogen equilibrium pressure as the ordinate, so as to obtain the hydrogen release PCT curve.

The invention has the beneficial effects that:

1. easy to install and dismantle: the sample chamber has simple and compact structure, is convenient for filling the hydrogen storage alloy, has good sealing performance, adopts threaded connection with the heating and cooling device, can ensure enough heat exchange area and has high heat exchange efficiency;

2. the temperature measurement precision is high: the k-type thermocouple can extend into the hydrogen storage alloy, can accurately measure the temperature in the sample chamber, is in threaded connection with the flange, is easy to detach and replace, is arranged separately from the hydrogen inlet and outlet, is easy to calibrate the volume, and also ensures that the hydrogen pipeline is smooth;

3. the temperature control is accurate: the heating device and the cooling device are combined for use, so that the time required by activation of the hydrogen storage alloy can be greatly reduced, and the temperature is accurately and quickly controlled;

4. the electromagnetic valve is effectively protected: the sample chamber is connected in series by adopting two electromagnetic valves with opposite compression directions, and different electromagnetic valves are respectively used in the hydrogen absorption/desorption process, so that the reasonable use of the electromagnetic valves can be protected, and the electromagnetic valves are prevented from being reversely compressed to influence the service life of the electromagnetic valves;

5. the device has high use efficiency: the device has simple structure, small occupied space, low cost investment and long cycle life;

6. and the full-automatic PCT curve test can be realized through the data acquisition unit and the computer.

Drawings

FIG. 1 is a schematic structural view of a hydrogen occluding alloy PCT curve testing device of the present invention;

FIG. 2 is a schematic diagram of a sample chamber according to the present invention;

FIG. 3 is a schematic view of the heating apparatus of the present invention;

fig. 4 is a schematic structural diagram of the cooling device of the present invention.

In the figure, 1, a hydrogen cylinder, 2, a helium cylinder, 3, a sample chamber, 4, a temperature control device, 5, a small gas cylinder, 6, a large gas cylinder, 7, a vacuum gauge, 8, a vacuum pump, 9, a throttle valve I, 10, a throttle valve II, 11, a throttle valve III, 12, a solenoid valve I, 13, a solenoid valve II, 14, a solenoid valve III, 15, a solenoid valve IV, 16, a solenoid valve V, 17, a solenoid valve VI, 18, a solenoid valve VII, 19, a solenoid valve VIII, 20, a solenoid valve IX, 21, a pressure sensor, 22, a pressure reducing valve, 23, a temperature sensor, 24, a computer, 25, a data collector, 26, a hydrogen inlet, 27, a filter plate, 28, a k-type thermocouple, 29, a flange, 30, a bolt and nut, 31, a sealing ring, 32, a stainless steel alloy pipe, 33, a hydrogen storage alloy, 34, an electric heating rod, 35, a sleeve I, 36, a base, 37, a water inlet, 39. and a sleeve II.

Detailed Description

The following further describes a specific embodiment of the present invention with reference to the drawings and technical solutions.

The hydrogen storage alloy PCT curve testing device is shown in figure 1 and comprises a sample chamber 3, a gas pipeline and a data acquisition unit; the gas pipeline comprises a main pipeline and branch pipelines; the sample chamber 3 is connected with a main pipeline through an electromagnetic valve III 14 and an electromagnetic valve IV 15, one end of the main pipeline is respectively connected with a hydrogen cylinder 1 and a helium cylinder 2 through a throttle valve I9, an electromagnetic valve I12, a throttle valve II 10 and an electromagnetic valve II 13, the other end of the main pipeline is respectively connected with the atmosphere and a vacuum gauge 7 through an electromagnetic valve IX 20, a pressure reducing valve 22, a throttle valve III 11, an electromagnetic valve VII 18 and an electromagnetic valve VIII 19, the vacuum gauge 7 is connected with a vacuum pump 8, a small gas cylinder 5 is connected through an electromagnetic valve V16, a large gas cylinder 6 is connected through an electromagnetic valve VI 17, a pressure sensor 21 is directly connected with the main, the electromagnetic valve I12, the electromagnetic valve II 13, the electromagnetic valve III 14, the electromagnetic valve IV 15, the electromagnetic valve V16, the electromagnetic valve VI 17, the electromagnetic valve VII 18, the electromagnetic valve VIII 19, the electromagnetic valve IX 20, the pressure sensor 21 and the temperature sensor 23 are connected with a data acquisition unit 25 of a data acquisition system.

As shown in fig. 2, the structure of the sample chamber 3 is as follows:

the sample chamber 3 comprises a hydrogen inlet 26, a hydrogen outlet 27, a k-type thermocouple 28, a flange 29, a bolt and a nut 30, a sealing ring 31 and a stainless steel alloy pipe 32; the upper end of a stainless steel alloy pipe 32 is provided with an opening, the upper end surface of the stainless steel alloy pipe is provided with a groove for placing a sealing ring 31, the sealing ring 31 is tightly pressed with a bolt nut 30 through a flange 29, the middle part of the flange 29 is provided with two through holes, the left hole is welded with a hydrogen inlet 26, the diameter of the bottom of the hydrogen inlet 26 is increased for placing a filter plate 27, the right hole is provided with a k-type thermocouple 28, and hydrogen storage alloy 33 is arranged in the stainless steel alloy pipe 32. The hydrogen inlet and outlet 26 is connected with a gas pipeline through an electromagnetic valve IV 15. The k-type thermocouple 28 is connected to the other through hole of the flange 29 by a screw. Four holes are symmetrically formed in the outer ring of the flange 29, bolts and nuts 30 are arranged in the holes, and the flange 29 is connected with the stainless steel alloy pipe 32 through the bolts and nuts 30. The stainless steel alloy pipe 32 is 304 stainless steel, is cylindrical, has an external thread structure outside, and is connected with the internal threads of the heating device and the cooling device in a matching way.

The hydrogen storage alloy PCT curve testing device is used for calibrating the volume of the system, and the method comprises the following steps:

first, the hydrogen cylinder 1 is opened, and the pressure in the large gas cylinder 6 is raised to 3 MPa. After standing for a period of time, recording the pressure P when the pressure and temperature in the large gas storage cylinder 6 are not changed₀And temperature T₀. And closing the electromagnetic valve VI 17, starting the vacuum pump 8 to vacuumize, and enabling the vacuum degree to reach 0.05 Pa. Opening the electromagnetic valve VI 17, standing for a period of time, and keeping the pressure and the temperature unchanged until the pressure and the temperature of the stabilized large gas storage bottle 6 are P₁And T₁The system volume V is calculated as follows:

P₀V₀ρ₀＝P₁(V₀+V)ρ₁

in the formula: vo: the volume of a large gas cylinder; v: the system volume; rho₀：P₀And T₀Density of hydrogen under conditions; rho₁：P₁And T₁Density of hydrogen under conditions.

The testing principle of the hydrogen storage alloy PCT curve testing device of the invention is as follows:

with LaNi₅For example, the testing principle is explained. Before testing, all manual valves including the throttle valve I9, the throttle valve II 10, the throttle valve III 11 and the pressure reducing valve 22 are opened, all electromagnetic valves are ensured to be in a closed state, and after testing is started, the opening and closing of the electromagnetic valves are controlled by the computer 24, so that all testing is completed. Wherein, solenoid valve IV 15 keeps normally open in the hydrogen absorption test, and solenoid valve III 14 keeps normally open in the hydrogen discharge test.

Hydrogen absorption test:

s1, loading hydrogen storage alloy 33 into a sample chamber 3, opening a solenoid valve III 14, a solenoid valve V16, a solenoid valve VI 17, a solenoid valve VII 18 and a solenoid valve VIII 19, starting a vacuum pump 8, vacuumizing until the vacuum degree reaches 0.05Pa, and closing the solenoid valve VII 18 and the solenoid valve VIII 19.

S2, opening an electromagnetic valve II 13, filling helium into the system, closing the electromagnetic valve II 13 after the pressure reaches 0.2MPa, opening an electromagnetic valve VII 18 and an electromagnetic valve VIII 19, starting a vacuum pump 8 to vacuumize until the vacuum degree reaches 0.05Pa, and closing an electromagnetic valve V16, an electromagnetic valve VI 17, an electromagnetic valve VII 18 and an electromagnetic valve VIII 19.

S3, installing a heating device, heating to 200 ℃, opening a solenoid valve I12, filling hydrogen into the system until the pressure reaches 2MPa, closing the solenoid valve I12, preserving the heat for 40min, removing the heating device, installing a cooling device in a temperature control device 4, cooling the temperature to room temperature, opening a solenoid valve IX 20, discharging the hydrogen, then opening a solenoid valve VII 18 and a solenoid valve VIII 19, starting a vacuum pump 8, vacuumizing, thus completing an activation process, and repeating the operation until the alloy is completely activated;

s4, after the activation of the alloy is finished, installing a heating device, heating to 200 ℃, opening the electromagnetic valve VII 18 and the electromagnetic valve VIII 19, starting the vacuum pump 8, and vacuumizing to finish the dehydrogenation of the alloy;

s5, opening the electromagnetic valve I12, closing other electromagnetic valves, introducing hydrogen into the system, closing the electromagnetic valve I12 after the pressure of the system reaches a set hydrogen absorption pressure value, collecting the environment temperature, the sample chamber temperature and the system pressure by the computer 24 and the data collector 25, opening the electromagnetic valve III 14, closing the electromagnetic valve III 14 after the system pressure is stable, collecting the environment temperature, the sample chamber temperature and the system pressure by the computer 24 and the data collector 25, repeating the operations, calculating the hydrogen absorption amount during each hydrogen charging by the computer 24 according to a gas state equation, establishing a coordinate system by taking the H/W ratio of hydrogen atoms to material atoms as a horizontal coordinate, and establishing a hydrogen absorption PCT curve by taking the hydrogen equilibrium pressure as a vertical coordinate.

And (3) hydrogen discharge test:

the hydrogen discharge test principle is the same as that of the hydrogen absorption test, firstly, the data acquisition system acquires the ambient temperature, the sample chamber temperature and the system pressure, then the electromagnetic valve in front of the sample chamber is closed, the system is vacuumized, the electromagnetic valve in front of the sample chamber is opened, after the system pressure is stabilized to a set hydrogen discharge pressure value, the data acquisition system acquires the ambient temperature, the sample chamber temperature and the system pressure, so that the first hydrogen discharge is completed, the operation is repeated, and a hydrogen discharge PCT curve is obtained by the computer 24 according to a gas state equation.