Liquefaction Temperature Testing System for Mixed Gas

Abstract

The present invention relates to a liquefaction temperature testing system for a mixed gas. The liquefaction temperature testing system includes: a gas supply device, a gas storage device, a pressure sensor, a temperature control device, and a gas chromatography-mass spectrometry instrument; the gas supply device is connected to the gas storage device, and the interior of the gas supply device is in communication with the interior of the gas storage device; the pressure sensor is connected to the gas supply device and is in communication with the interior of the gas storage device; the gas chromatography-mass spectrometry instrument is connected to the gas supply device and is in communication with the interior of the gas storage device; both the gas storage device and the pressure sensor are disposed within the temperature control device. The above liquefaction temperature testing system for a mixed gas facilitates the determination of the liquefaction temperature of the mixed gas.

Description

Technical Field

[0001] The present invention relates to the technical field of gas testing, and particularly to a liquefaction temperature testing system for a mixed gas. Background Art

[0002] For the liquefaction temperature of gases, different gases have different liquefaction temperatures. Some gases have relatively high liquefaction temperatures, while some have relatively low liquefaction temperatures. For gases with relatively high liquefaction temperatures, when used as industrial gases, balance gases are usually filled to maintain their relatively low partial pressures, thereby reducing their liquefaction temperatures and improving the low-temperature stability of the mixed gas.

[0003] For example, in the field of insulating gas applications, some new insulating gases used include C4F7N (perfluoroisobutyronitrile, boiling point at about -4.7 °C at 1 atm), C5F 10 O (perfluoropropyl vinyl ether, liquefaction temperature at about 26.5 °C at 1 atm), etc., which have relatively high liquefaction temperatures and must be filled with balance gases such as CO2 or N2 to form a mixed gas. Since the new insulating gases lack relevant thermophysical parameters and are prone to introducing errors in the calculation process, in order to master the liquefaction temperature of the mixed gas and the composition change under low-temperature conditions, and evaluate its low-temperature use performance and use temperature range, it is necessary to conduct experimental determination of its liquefaction temperature.

[0004] However, for the existing determination of liquefaction temperature, only single gases can be determined by measuring the saturated vapor pressure (the partial pressure of the gas in the air, which usually increases with the increase of temperature), and it is difficult to determine the liquefaction temperature of the mixed gas. Summary of the Invention

[0005] Based on this, in view of the problem that the existing determination of liquefaction temperature can only determine single gases and it is difficult to determine the liquefaction temperature of the mixed gas, it is necessary to provide a liquefaction temperature testing system for a mixed gas.

[0006] A liquefaction temperature testing system for a mixed gas includes: a gas supply device, a gas storage device, a pressure sensor, a temperature control device, and a gas chromatography-mass spectrometry (GC-MS) instrument;

[0007] The gas supply device is connected to the gas storage device, and the interior of the gas supply device is in communication with the interior of the gas storage device;

[0008] The pressure sensor is connected to the gas supply device and is in communication with the interior of the gas storage device;

[0009] The gas chromatography-mass spectrometry (GC-MS) instrument is connected to the gas supply device and is in communication with the interior of the gas storage device;

[0010] Both the gas storage device and the air pressure sensor are arranged inside the temperature control device.

[0011] In one embodiment, the liquefaction temperature testing system further includes a data acquisition card, which is electrically connected to the air pressure sensor and is used for collecting the signals generated by the air pressure sensor.

[0012] In one embodiment, the liquefaction temperature testing system further includes a mass flow meter. The gas supply device is connected to the gas storage device through the mass flow meter, and the interiors of the gas supply device, the mass flow meter, and the gas storage device are sequentially communicated. The mass flow meter is used for measuring the mass of the gas flowing from the gas supply device into the gas storage device.

[0013] In one embodiment, the liquefaction temperature testing system further includes a pressure reducing device. The gas supply device is connected to the gas storage device through the pressure reducing device, and the interiors of the gas supply device, the pressure reducing device, and the gas storage device are sequentially communicated. The pressure reducing device is used for reducing the pressure of the gas flowing out of the gas supply device and then flowing it into the gas storage device.

[0014] In one embodiment, the liquefaction temperature testing system further includes a constant flow device. The gas supply device is connected to the gas storage device through the constant flow device, and the interiors of the gas supply device, the constant flow device, and the gas storage device are sequentially communicated. The constant flow device is used for reducing the pressure of the gas flowing out of the gas supply device and then flowing it into the gas storage device.

[0015] In one embodiment, the liquefaction temperature testing system further includes a vacuum pumping device. The interior of the vacuum pumping device is connected to the gas supply device, and the interior of the vacuum pumping device and the gas supply device are in mutual communication.

[0016] In one embodiment, a first ferrule fitting is provided on the gas storage device, and the first ferrule fitting is communicated with the interior of the gas storage device;

[0017] The gas supply device is detachably connected to the first ferrule fitting through a first gas supply pipeline, and the interior of the first gas supply pipeline is respectively communicated with the interior of the gas supply device and the interior of the first ferrule fitting.

[0018] In one embodiment, a second ferrule fitting is provided on the gas storage device, and the second ferrule fitting is communicated with the interior of the gas storage device;

[0019] The air pressure sensor is detachably connected to the second ferrule joint through the second air supply pipeline, and the interior of the second air supply pipeline is respectively communicated with the interior of the air pressure sensor and the second ferrule joint.

[0020] In one embodiment, a third ferrule joint is provided on the gas storage device, and the third ferrule joint is communicated with the interior of the gas storage device;

[0021] The gas chromatography - mass spectrometry instrument is detachably connected to the third ferrule joint through the third air supply pipeline, and the interior of the third air supply pipeline is respectively communicated with the interior of the gas chromatography - mass spectrometry instrument and the third ferrule joint.

[0022] In one embodiment, the outer surface of the third air supply pipeline is coated with a heat - insulating layer.

[0023] In the above - mentioned liquefaction temperature test system for the mixed gas, a certain pressure of the gas to be measured is filled into the gas storage device through the gas supply device. At the same time, the temperature control system is started to control the temperature within a preset range. After the temperature inside the gas storage device in the temperature control system reaches the set temperature, the temperature and air pressure data of the mixed gas at different preset temperatures are measured by the air pressure sensor, and the content data of each gas component in the mixed gas at different preset temperatures is measured by the gas chromatography - mass spectrometry instrument. By converting the gas content data into gas partial pressure data and making a T (temperature) - P (partial pressure) curve graph, the inflection point of the curve in the curve graph corresponds to the liquefaction temperature point, thereby obtaining the liquefaction temperature of each gas, which facilitates the determination of the liquefaction temperature of the mixed gas. Description of the Drawings

[0024] Figure 1 This is a liquefaction temperature test system for the mixed gas according to an embodiment of the present application. Detailed Embodiments

[0025] In order to make the above - mentioned objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention is made with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0026] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature. Also, the "above" and "below" in the present invention only represent relative positions and do not represent absolute positions.

[0027] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation.

[0028] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0029] The present application provides a liquefaction temperature test system for a mixed gas. In one embodiment, the liquefaction temperature test system includes a gas supply device, a gas storage device, a pressure sensor, a temperature control device and a gas chromatography-mass spectrometry instrument; the gas supply device is connected to the gas storage device, and the interior of the gas supply device is in communication with the interior of the gas storage device; the pressure sensor is connected to the gas supply device and is in communication with the interior of the gas storage device; the gas chromatography-mass spectrometry instrument is connected to the gas supply device and is in communication with the interior of the gas storage device; both the gas storage device and the pressure sensor are disposed in the temperature control device.

[0030] The liquefaction temperature testing system for the above-mentioned mixed gas fills a test gas at a certain pressure into a gas storage device through a gas supply device, and at the same time starts a temperature control system to control the temperature within a preset range. After the temperature inside the gas storage device within the temperature control system reaches the set temperature, the temperature and pressure data of the mixed gas at different preset temperatures are measured by a pressure sensor, and the content data of each gas component in the mixed gas at different preset temperatures are measured by a gas chromatography-mass spectrometry (GC-MS) instrument. By converting the gas content data into gas partial pressure data and making a T (temperature)-P (partial pressure) curve graph, the inflection point of the curve in the curve graph corresponds to the liquefaction temperature point, thereby obtaining the liquefaction temperature of each gas, which facilitates the determination of the liquefaction temperature of the mixed gas.

[0031] To better understand the liquefaction temperature testing system for the mixed gas of the present application, the liquefaction temperature testing system of the present application will be further described below with reference to the accompanying drawings.

[0032] As Figure 1 shown, the liquefaction temperature testing system 10 for the mixed gas includes: a gas supply device 100, a gas storage device 200, a pressure sensor 300, a temperature control device 400, and a gas chromatography-mass spectrometry (GC-MS) instrument 500. The gas supply device 100 is used to provide the test gas, the gas storage device 200 is used to store the test gas, the pressure sensor 300 is used to test the temperature and pressure data of the stored test gas, the temperature control device 400 is used to control the temperature of the stored test gas within a preset range, and the gas chromatography-mass spectrometry (GC-MS) instrument 500 is used to measure the content data of the test gas components.

[0033] The gas supply device 100 is connected to the gas storage device 200, and the inside of the gas supply device 100 is in communication with the inside of the gas storage device 200. In one embodiment, the gas supply device 100 has a sealed cavity, the gas storage device 200 has a sealed cavity, and the communication between the inside of the gas supply device 100 and the inside of the gas storage device 200 means that the sealed cavity of the gas supply device 100 is in communication with the sealed cavity of the gas storage device 200, so that the gas in the sealed cavity of the gas supply device 100 can flow into the sealed cavity of the gas storage device 200.

[0034] The pressure sensor 300 is connected to the gas supply device 100, and the pressure sensor 300 is in communication with the inside of the gas storage device 200. In one embodiment, the gas storage device 200 has a sealed cavity, and the communication between the pressure sensor 300 and the inside of the gas storage device 200 means that the pressure sensor 300 is in communication with the sealed cavity of the gas storage device 200, so that the pressure sensor 300 can contact the gas in the sealed cavity of the gas storage device 200.

[0035] The gas chromatography - mass spectrometry (GC - MS) instrument 500 is connected to the gas supply device 100, and the interior of the GC - MS instrument 500 communicates with the interior of the gas storage device 200. In one embodiment, the gas storage device 200 has a sealed chamber, and the GC - MS instrument 500 has a measurement chamber. The internal communication between the GC - MS instrument 500 and the gas storage device 200 means that the measurement chamber of the GC - MS instrument 500 communicates with the interior of the gas storage device 200, so that the gas in the sealed chamber of the gas storage device 200 can flow into the measurement chamber of the GC - MS instrument 500.

[0036] Both the gas storage device 200 and the pressure sensor 300 are disposed within the temperature control device 400. In one embodiment, the temperature control device 400 has a receiving chamber, and both the gas storage device 200 and the pressure sensor 300 are disposed within the receiving chamber of the temperature control device 400, so that the temperature control device 400 can control the temperature of the gas storage device 200 and the pressure sensor 300 can measure the actual temperature of the gas storage device 200.

[0037] In one embodiment, the gas supply device 100 is a gas cylinder. Using a gas cylinder as the gas supply device 100 can achieve the safe storage and transportation of gas.

[0038] In one embodiment, the gas storage device 200 is a stainless - steel sealed container. Using a stainless - steel sealed container can improve the sealing performance of the gas storage device 200 and prevent gas leakage.

[0039] In one embodiment, the temperature control device 400 is a refrigerator. Using a refrigerator as the temperature control device 400 can precisely adjust the temperature inside the temperature control device 400. In one embodiment, the refrigerator is a low - temperature refrigerator, with a temperature range of - 80°C to 0°C, an adjustment accuracy of 0.1°C, and a temperature uniformity of ±0.5°C.

[0040] In one embodiment, the GC - MS instrument 500 is a gas chromatography - mass spectrometry instrument. In one embodiment, the GC - MS instrument 500 has an automatic six - way gas sampling valve for gas sampling. In one embodiment, the GC - MS instrument 500 also has a split / splitless injection port for introducing samples into the chromatographic column for separation. In one embodiment, the GC - MS instrument 500 also has a mass spectrometry detector for detecting gas components.

[0041] In one embodiment, the gas supply device 100 is connected to the automatic six-way gas injection valve of the gas chromatography-mass spectrometry instrument 500. In this way, when the automatic six-way gas injection valve is opened, the gas in the gas supply device 100 enters the measurement chamber inside the gas supply device 100 and is introduced into the chromatographic column through the split / splitless injection port. Since the adsorbent on the chromatographic column has different adsorption forces for each gas component, after a period of time, the running speeds of the components in the chromatographic column are also different. The component with the weakest adsorption force is easily desorbed, leaves the chromatographic column first and enters the mass spectrometer detector, and the component with the strongest adsorption force is the least likely to be desorbed and leaves the chromatographic column last and enters the mass spectrometer detector. Thus, the content data of each component are separated from each other in the chromatographic column and then enter the mass spectrometer detector respectively to be detected and recorded.

[0042] In order to collect the signals generated by the pressure sensor 300, in one embodiment, the liquefaction temperature test system further includes a data acquisition card 600. The data acquisition card 600 is electrically connected to the pressure sensor 300, and the data acquisition card 600 is used to collect the signals generated by the pressure sensor 300. In this way, all the signals generated when the pressure sensor 300 senses the gas in the gas storage device 200 can be collected by the data acquisition card, which is more convenient for data collection and subsequent analysis.

[0043] In one embodiment, the data acquisition card 600 is electrically connected to the pressure sensor 300 through a wire. In another embodiment, the data acquisition card 600 is electrically connected to the pressure sensor 300 through a data line.

[0044] In order to process the collected or measured data, in one embodiment, the liquefaction temperature test system further includes a computer subsystem 700. The computer subsystem 700 is electrically connected to the data acquisition card 600 and the gas chromatography-mass spectrometry instrument 500 respectively. In this way, the content data measured by the gas chromatography-mass spectrometry instrument 500 and the temperature and pressure data measured by the pressure sensor 300 collected by the data acquisition card 600 can be processed by the computer subsystem 700 to obtain the liquefaction temperature of the mixed gas. In one embodiment, the computer subsystem 700 is a processing system on a computer.

[0045] In order to accurately measure the mass of the gas to be measured provided by the gas supply device 100, in one embodiment, the liquefaction temperature test system further includes a mass flow meter 800. The gas supply device 100 is connected to the gas storage device 200 through the mass flow meter 800, and the inside of the gas supply device 100, the inside of the mass flow meter 800, and the inside of the gas storage device 200 are communicated in sequence. The mass flow meter 800 is used to measure the mass of the gas flowing from the gas supply device 100 into the gas storage device 200. By arranging the mass flow meter 800 between the gas supply device 100 and the gas storage device 200, the mass of the gas to be measured flowing out of the gas supply device 100 before entering the gas storage device 200 can be accurately measured.

[0046] In one embodiment, the mass flow meter 800 has a measurement chamber, and the inside of the gas supply device 100, the inside of the mass flow meter 800, and the inside of the gas storage device 200 are communicated in sequence, that is, the sealed chamber of the gas supply device 100, the measurement chamber of the mass flow meter 800, and the sealed chamber of the gas storage device 200 are communicated in sequence.

[0047] In order to reduce the pressure of the gas to be measured from high pressure to low pressure, in one embodiment, the liquefaction temperature test system further includes a pressure reducing device 910. The gas supply device 100 is connected to the gas storage device 200 through the pressure reducing device 910, and the inside of the gas supply device 100, the inside of the pressure reducing device 910, and the inside of the gas supply device 100 are communicated in sequence. The pressure reducing device 910 is used to reduce the pressure of the gas flowing out of the gas supply device 100 and then flow into the gas storage device 200. In one embodiment, the pressure reducing device 910 is a cylinder pressure reducing valve. By arranging the pressure reducing device 910, the gas to be measured flowing out of the gas supply device 100 is reduced from high pressure to low pressure and then enters the gas storage device 200 for relevant tests, so that the pressure of the gas to be measured can meet the requirements.

[0048] In one embodiment, the pressure reducing device 910 has a pressure reducing chamber, and the inside of the gas supply device 100, the inside of the pressure reducing device 910, and the inside of the gas storage device 200 are communicated in sequence, that is, the sealed chamber of the gas supply device 100, the pressure reducing chamber of the pressure reducing device 910, and the sealed chamber of the gas storage device 200 are communicated in sequence.

[0049] In one embodiment, to make the gas flow rate stable, the liquefaction temperature test system further includes a constant flow device 920. The gas supply device 100 is connected to the gas storage device 200 through the constant flow device 920, and the inside of the gas supply device 100, the inside of the constant flow device 920, and the inside of the gas supply device 100 are connected in sequence. The constant flow device 920 is configured to make the gas flow rate stable after flowing out of the gas supply device 100 and then flow into the gas storage device 200. In one embodiment, the constant flow device 920 is a gas constant flow valve. By providing the constant flow device 920, the gas to be tested flows out of the gas supply device 100, passes through the constant flow device 920 with a gentle flow rate, and then enters the gas storage device 100.

[0050] In one embodiment, the constant flow device 920 has a constant flow chamber, and the inside of the gas supply device 100, the inside of the constant flow device 920, and the inside of the gas storage device 200 are connected in sequence, that is, the sealed chamber of the gas supply device 100, the constant flow chamber of the constant flow device 920, and the sealed chamber of the gas storage device 200 are connected in sequence.

[0051] In one embodiment, to ensure the accuracy of the test, the liquefaction temperature test system further includes a vacuum pumping device 930. The vacuum pumping device 930 is connected to the gas supply device 100, and the inside of the vacuum pumping device 930 is in communication with the inside of the gas supply device 100. By providing the vacuum pumping device 930, the system is evacuated before the experiment starts to discharge the interfering gases in the system, ensuring the accuracy of the test. At the same time, the evacuation can also detect whether the airtightness of the system is good.

[0052] In one embodiment, the vacuum pumping device 930 has a receiving chamber, and the inside of the vacuum pumping device 930 is in communication with the inside of the gas supply device 100, that is, the receiving chamber of the vacuum pumping device 930 is in communication with the inside of the gas supply device 100. In one embodiment, the vacuum pumping device 930 is a vacuum pump. In one embodiment, the vacuum pumping device 930 includes a vacuum control valve and a vacuum pump. The vacuum pump is connected to the gas supply device 100 through the vacuum control valve, and the vacuum control valve is used to control whether the gas supply device 100 and the vacuum pump are in communication.

[0053] In order to facilitate the connection between the gas supply device 100 and the gas storage device 200, in one embodiment, a first ferrule fitting is provided on the gas storage device 200, and the first ferrule fitting is in communication with the interior of the gas storage device 200; the gas supply device 100 is detachably connected to the first ferrule fitting through a first gas supply pipeline, and the interior of the first gas supply pipeline is respectively in communication with the interior of the gas supply device 100 and the interior of the first ferrule fitting. By providing the first ferrule fitting on the gas storage device 200, the gas supply device 100 can be detachably connected to the first ferrule fitting through the first gas supply pipeline, facilitating the connection between the gas supply device 100 and the gas storage device 200 and enabling the internal communication between the two to allow gas to flow. At the same time, it is convenient to disassemble the gas supply device 100 and the gas storage device 200 for separate transportation, storage, maintenance or replacement.

[0054] In order to facilitate the connection between the pressure sensor 300 and the gas storage device 200, in one embodiment, a second ferrule fitting is provided on the gas storage device 200, and the second ferrule fitting is in communication with the interior of the gas storage device 200; the pressure sensor 300 is detachably connected to the second ferrule fitting through a second gas supply pipeline, and the interior of the second gas supply pipeline is respectively in communication with the interior of the pressure sensor 300 and the interior of the second ferrule fitting. By providing the second ferrule fitting on the gas storage device 200, the pressure sensor 300 can be detachably connected to the second ferrule fitting through the second gas supply pipeline, facilitating the connection between the pressure sensor 300 and the gas storage device 200 and enabling the internal communication between the two to allow gas to flow. At the same time, it is convenient to disassemble the pressure sensor 300 and the gas storage device 200 for separate transportation, storage, maintenance or replacement.

[0055] In order to facilitate the connection between the gas chromatography - mass spectrometry instrument 500 and the gas storage device 200, in one embodiment, a third ferrule fitting is provided on the gas storage device 200, and the third ferrule fitting is in communication with the interior of the gas storage device 200; the gas chromatography - mass spectrometry instrument 500 is detachably connected to the third ferrule fitting through the third gas supply pipeline, and the interior of the third gas supply pipeline is respectively in communication with the interior of the gas chromatography - mass spectrometry instrument 500 and the interior of the third ferrule fitting. By providing the third ferrule fitting on the gas storage device 200, the gas chromatography - mass spectrometry instrument 500 can be detachably connected to the third ferrule fitting through the third gas supply pipeline, facilitating the connection between the gas chromatography - mass spectrometry instrument 500 and the gas storage device 200 and enabling the internal communication between the two to allow gas to flow. At the same time, it is convenient to disassemble the gas supply device 100 and the gas storage device 200 for separate transportation, storage, maintenance or replacement.

[0056] In one embodiment, the gas storage device 200 is provided with a first ferrule fitting, a second ferrule fitting and a third ferrule fitting, and the first ferrule fitting, the second ferrule fitting and the third ferrule fitting are respectively communicated with the inside of the gas storage device 200; the gas supply device 100 is detachably connected to the first ferrule fitting through a first gas supply pipeline, and the inside of the first gas supply pipeline is respectively communicated with the inside of the gas supply device 100 and the inside of the first ferrule fitting; the pressure sensor 300 is detachably connected to the second ferrule fitting through a second gas supply pipeline, and the inside of the second gas supply pipeline is respectively communicated with the pressure sensor 300 and the inside of the second ferrule fitting; the gas chromatography-mass spectrometry instrument 500 is detachably connected to the third ferrule fitting through the third gas supply pipeline, and the inside of the third gas supply pipeline is respectively communicated with the gas chromatography-mass spectrometry instrument 500 and the inside of the third ferrule fitting.

[0057] In order to make the temperature of the gas measured by the gas chromatography-mass spectrometry instrument 500 consistent with the temperature of the gas in the gas storage device 200, in one embodiment, the outer surface of the third gas supply pipeline is coated with a heat-insulating layer. By coating the heat-insulating layer on the outer surface of the third gas supply pipeline connecting the gas storage device 200 and the gas chromatography-mass spectrometry instrument 500, the temperature of the gas flowing out of the gas storage device 200 can remain consistent after passing through the third gas supply pipeline and flowing into the gas chromatography-mass spectrometry instrument 500, reducing the measurement error.

[0058] In order to be able to fully remove the air in the system, in one embodiment, please refer to again Figure 1 , the liquefaction temperature test system further includes a vacuum pumping device 930, the inside of the vacuum pumping device 930 is connected to the gas supply device 100, and the vacuum pumping device 930 and the inside of the gas supply device 100 are communicated with each other; the liquefaction temperature test system further includes a gas pump 940, one end of the gas pump 940 is connected to the gas storage device 200, the other end of the gas pump 940 is connected to the gas chromatography-mass spectrometry instrument 500, and the inside of the gas pump 940 is respectively communicated with the inside of the gas storage device 200 and the gas chromatography-mass spectrometry instrument 500. By arranging the gas pump 940 between the gas storage device 200 and the gas chromatography-mass spectrometry instrument 500, when the gas pump 940 works, it can promote the gas circulation in the system and remove the air in the system.

[0059] In one embodiment, the gas to be measured is a mixed gas of perfluoroisobutyronitrile (C4F7N) and carbon dioxide (CO2) (10% C4F7N / 90% CO2) as the gas to be measured. In one embodiment, the gas storage device is a refrigerator at -80°C. In one embodiment, the pressure sensor model is UNIK5000, with a range of 0 to 1 MPa, an accuracy of four ten-thousandths, and an error of 0.4 kPa for the full range. In one embodiment, the data acquisition card model is USB-6001. In one embodiment, the injection method of the gas chromatography-mass spectrometry is gas automatic six-port valve injection.

[0060] In one embodiment, the steps of testing the mixed gas using the liquefaction temperature test system of the present application are as follows:

[0061] Step (1), Assemble the liquefaction temperature test system for the mixed gas, and fill it with 0.65 MPa of gas. Keep it for 24 h. When the pressure drop value is less than 2 kPa, the airtightness of the system can be considered good. Detect its airtightness. When the airtightness of the system is good, start the vacuum pump and pump the system pressure to about 1 kPa;

[0062] Step (2), Close the stop valve, fill it with the gas to be measured until 0.1 MPa, and start the gas pump to circulate for 5 min to discharge the air in the system. Then start the vacuum pump again, open the stop valve, and pump the system pressure to about 1 kPa;

[0063] Step (3), Implement step (2) two more times to ensure that the residual air volume in the system is less than 10 ppm;

[0064] Step (4), Fill it with 0.65 MPa of the gas to be measured;

[0065] Step (5), Start the temperature control system and control the temperature within the set temperature range;

[0066] Step (6), After the temperature in the sealed chamber reaches the set temperature, record the sensor data, including temperature and / or pressure;

[0067] Step (7), Start the pump / valve that drives the gas circulation to make the gas in the system mix evenly, and determine the contents of C4F7N and CO2 in the gas by gas chromatography-mass spectrometry;

[0068] Step (8), Repeat steps (5)-(7) to measure the gas component content data at different temperature points.

[0069] In one embodiment, the steps of obtaining data according to the liquefaction temperature test system of the present application and calculating the liquefaction temperature of the mixed gas are as follows:

[0070] Step (1): At normal temperature and pressure, a mixed gas is introduced into the gas storage device through a gas supply device. The amount of the introduced gas is measured by a mass flowmeter, and at the same time, the system gas pressure value is recorded by a pressure sensor. The volume of the entire system is calibrated using the real gas state equation, that is, the van der Waals gas state equation for 1 mole of gas with temperature, pressure, and molar volume being T, p, and V0 respectively.

[0071] Step (2): The system pipeline is cleaned through a vacuum pump, enabling the system to be filled with the mixed gas to be measured.

[0072] Step (3): By adjusting the system temperature, the temperature-pressure curve is measured and obtained.

[0073] Step (4): The system is circulated through a gas pump to make the gas distribution in each part of the system uniform, and the quantitative tube of the automatic injection valve of the gas chromatography-mass spectrometry is filled with gas.

[0074] Step (5): The content of the target gas component is measured using a gas chromatography-mass spectrometry, and then the temperature-target gas component partial pressure curve is obtained. For example, through the gas state equation, the gas component content is converted into gas partial pressure values, and by plotting the gas partial pressure data obtained under different temperature conditions, the temperature-gas partial pressure curve can be obtained.

[0075] Step (6): Analyze the target gas partial pressure curve to obtain the liquefaction temperature of the target gas.

[0076] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of concise description, 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, it should be considered as within the scope described in this specification.

[0077] The above-described embodiments only represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent should be subject to the appended claims.

Claims

1. A liquefaction temperature testing system for a mixed gas, characterized in that, include: Gas supply device, gas storage device, air pressure sensor, temperature control device, data acquisition card, mass flow meter, pressure reducing device, constant flow device, vacuum device and gas chromatography-mass spectrometry; The gas supply device is connected to the gas storage device, and the interior of the gas supply device is communicated with the interior of the gas storage device; The air pressure sensor is connected to the air supply device, and the air pressure sensor is in communication with the interior of the air storage device; The gas chromatograph-mass spectrometer is connected to the gas supply device, and the gas chromatograph-mass spectrometer is in communication with the interior of the gas storage device; The gas storage device and the air pressure sensor are both arranged in the temperature control device; The gas storage device is provided with a first ferrule joint, and the first ferrule joint is communicated with the interior of the gas storage device; The air supply device is detachably connected to the first ferrule joint via a first air supply pipeline, and the interior of the first air supply pipeline is communicated with the interior of the air supply device and the interior of the first ferrule joint respectively; The gas storage device is provided with a second ferrule joint, and the second ferrule joint is communicated with the interior of the gas storage device; The air pressure sensor is detachably connected to the second ferrule joint via a second air supply pipe, and the interior of the second air supply pipe is communicated with the interiors of the air pressure sensor and the second ferrule joint respectively; The gas storage device is provided with a third ferrule joint, and the third ferrule joint is communicated with the interior of the gas storage device; The gas chromatograph-mass spectrometer is detachably connected to the third ferrule joint via a third gas supply pipeline, and the interior of the third gas supply pipeline is respectively connected to the interiors of the gas chromatograph-mass spectrometer and the third ferrule joint; The data acquisition card is electrically connected to the air pressure sensor, and the data acquisition card is used to collect the signal generated by the air pressure sensor; The gas supply device is connected to the gas storage device through the mass flow meter, and the interior of the gas supply device, the interior of the mass flow meter and the interior of the gas storage device are sequentially connected, and the mass flow meter is used to measure the mass of the gas flowing from the gas supply device into the gas storage device; The gas supply device is connected to the gas storage device through the pressure reducing device, and the interior of the gas supply device, the interior of the pressure reducing device and the interior of the gas supply device are sequentially connected, and the pressure reducing device is used to reduce the pressure of the gas flowing out of the gas supply device and then flow it into the gas storage device; The gas supply device is connected to the gas storage device through the constant flow device, and the interior of the gas supply device, the interior of the constant flow device and the interior of the gas supply device are sequentially connected, and the constant flow device is used to reduce the pressure of the gas flowing out of the gas supply device and then flow into the gas storage device; The interior of the vacuum pumping device is connected to the air supply device, and the interiors of the vacuum pumping device and the air supply device are communicated with each other.

2. The liquefaction temperature test system according to claim 1, wherein The outer surface of the third air supply pipe is covered with a thermal insulation layer.

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