阅读说明：本技术 常温气态物质转化为低温液体的定量进样装置及进样方法 (Quantitative sample introduction device and method for converting normal-temperature gaseous substances into low-temperature liquid ) 是由 金满平 王婷 王亚琴 厉鹏 张全 于 2020-05-28 设计创作，主要内容包括：本发明公开了一种常温气态物质转化为低温液体的定量进样装置及进样方法,涉及石油化工安全生产技术领域。其解决了沸点接近常温的气相物料在绝热量热测试过程中进样较难达到化学反应所需的物料配比压力、与其他物料不能均匀混合、增压进料具有燃爆安全隐患等问题。该进样装置包括氮气钢瓶、气相物料钢瓶、缓冲罐、压力活塞装置、电子秤、低温冷却循环装置及绝热量热测试装置,通过低温冷却循环装置将进入缓冲罐内的气相物料进行降温,并将其转化为液态；通过电子秤来记录进入转化为液态的气相物料进入压力活塞装置的质量；通过绝热量热测试装置对电子秤记录充足的物料进行测量。本发明可提高该类气相物料参与的绝热量热测试结果的准确性。(The invention discloses a quantitative sample injection device and a sample injection method for converting normal-temperature gaseous substances into low-temperature liquid, and relates to the technical field of petrochemical engineering safety production. The problems that a gas-phase material with a boiling point close to normal temperature is difficult to sample to reach the material proportioning pressure required by chemical reaction in an adiabatic calorimetry test process, cannot be uniformly mixed with other materials, and has potential safety hazards in combustion and explosion in pressurization feeding are solved. The sample introduction device comprises a nitrogen gas steel cylinder, a gas-phase material steel cylinder, a buffer tank, a pressure piston device, an electronic scale, a cryogenic cooling circulating device and an adiabatic calorimetry testing device, wherein the cryogenic cooling circulating device is used for cooling the gas-phase material entering the buffer tank and converting the gas-phase material into liquid; recording the mass of the gas-phase material converted into liquid state entering the pressure piston device through an electronic scale; and measuring the sufficient materials recorded by the electronic scale through an adiabatic calorimetric testing device. The invention can improve the accuracy of the adiabatic calorimetry test result of the gas-phase material.)

1. The utility model provides a quantitative sampling device that normal atmospheric temperature gaseous state material turned into cryogenic liquids, its includes nitrogen gas steel bottle, gaseous phase material steel bottle, buffer tank, pressure piston device, electronic scale, cryogenic cooling circulating device, adiabatic calorimetric test device, relevant pipeline and valve, its characterized in that: the gas-phase material entering the buffer tank is cooled through the low-temperature cooling circulation device and is converted into a liquid state; the mass of the gas-phase material converted into liquid state entering the pressure piston device is recorded by the electronic scale.

2. The quantitative sample introduction device for converting the normal-temperature gaseous substance into the cryogenic liquid according to claim 1, characterized in that: and the adiabatic calorimetric testing device is used for measuring the materials which are sufficiently recorded by the electronic scale.

3. The quantitative sample introduction device for converting the normal-temperature gaseous substance into the cryogenic liquid according to claim 2, characterized in that: the buffer tank comprises a tank wall and a tank body, wherein a cooling coil and a heat-insulating material are arranged in the tank wall, and the cooling coil is communicated with the low-temperature cooling circulating device, so that cold circulation of the tank body is formed.

4. The quantitative sample introduction device for converting the normal-temperature gaseous substance into the cryogenic liquid according to claim 3, characterized in that: the tank body is connected with a first pipeline, a second pipeline and a third pipeline, wherein the first pipeline is connected with the gas-phase material steel cylinder, the gas-phase material is conveyed into the tank body through the first pipeline, the second pipeline is connected with a vacuum pump, a vacuumizing pipeline valve is connected to the second pipeline, and the tank body is vacuumized through the vacuum pump; the third pipeline is connected with the pressure piston device and used for conveying liquid materials formed after cooling through the low-temperature cooling circulating device to the pressure piston device.

5. The quantitative sample introduction device for converting the normal-temperature gaseous substance into the cryogenic liquid according to claim 4, characterized in that: the electronic scale is positioned below the pressure piston device, the pressure piston device comprises a piston cavity and a piston pull rod, the piston pull rod horizontally reciprocates in the piston cavity, a handle is arranged at the end part of the piston pull rod far away from the piston cavity, and materials converted into liquid in the buffer tank are pumped into the pressure piston device by pulling the handle.

6. The quantitative sample introduction device for converting the normal-temperature gaseous substance into the cryogenic liquid according to claim 5, characterized in that: the piston chamber is connected to the nitrogen steel cylinder through a fourth pipeline connected with the piston chamber, a fifth pipeline is connected between the piston chamber and the adiabatic heat testing device, and materials enough recorded by the electronic scale are sent to the adiabatic heat testing device through the fifth pipeline for measurement.

7. The quantitative sample introduction device for converting the normal-temperature gaseous substance into the cryogenic liquid according to claim 6, characterized in that: the adiabatic quality testing device comprises a calorimetric tank, and the calorimetric tank is provided with a calorimetric tank temperature sensor and a calorimetric tank pressure sensor.

8. The quantitative sample introduction device for converting the normal-temperature gaseous substance into the cryogenic liquid according to claim 7, characterized in that: the buffer tank is provided with a material pressure sensor, a tank wall temperature sensor and a material temperature sensor.

9. The quantitative sample introduction device for converting the normal-temperature gaseous substance into the cryogenic liquid according to claim 5, characterized in that: the periphery of the piston chamber is coated by a heat insulation material.

10. The quantitative sample introduction device for converting the normal-temperature gaseous substance into the cryogenic liquid according to claim 8, characterized in that: and valves are arranged on the first pipeline, the second pipeline, the third pipeline, the fourth pipeline and the fifth pipeline.

11. The quantitative sample introduction device for converting the normal-temperature gaseous substance into the cryogenic liquid according to claim 5, characterized in that: the outer wall of the piston chamber is also provided with a coil pipe for cooling and cooling the material, and the coil pipe is connected with the low-temperature cooling circulating device to form cold circulation.

12. A quantitative sample introduction method for converting normal-temperature gaseous substances into low-temperature liquid is characterized by comprising the following steps: the quantitative sample injection device for converting the normal-temperature gaseous substance into the cryogenic liquid is adopted, and the method comprises the following steps:

s1, firstly, detecting the air tightness of the device, and sending gas-phase materials into the buffer tank after the air tightness is qualified;

s2, starting a low-temperature cooling circulation device, cooling the buffer tank until the temperature in the buffer tank is reduced to the boiling point temperature of the gas-phase material below at least 10 ℃, and at the moment, completely converting the gas-phase material in the buffer tank into a liquid state;

s3, starting the electronic scale and the pressure piston device, pumping all gas-phase materials which are converted into liquid in the buffer tank into the pressure piston device by controlling a piston pull rod and a handle of the pressure piston device, and recording the mass change of the electronic scale;

and S4, stopping the material entering when the record of the electronic scale reaches a certain mass, inputting nitrogen into the pressure piston device, and sending the material into the adiabatic calorimetry testing device for measurement by controlling the nitrogen pressure in the pressure piston device according to the record of the electronic scale.

13. The quantitative sample injection method for converting the normal-temperature gaseous substance into the cryogenic liquid as claimed in claim 12, wherein the quantitative sample injection method comprises the following steps: in step S4, after the materials in the pressure piston device are all sent to the adiabatic testing device, the nitrogen pressure in the pressure piston device is released to the normal pressure.

Technical Field

The invention relates to the technical field of petrochemical engineering safety production, in particular to a quantitative sample injection device and a sample injection method for converting normal-temperature gaseous substances into low-temperature liquid.

Background

In the field of petrochemical industry, technological reactions involved in the production process of many chemical products belong to strong exothermic reactions, such as decomposition, polymerization, nitration, oxidation, peroxidation and the like. If the conditions are improperly controlled or misoperation occurs in the production process, heat in the reactor is easily accumulated, and the reaction is out of control. Therefore, in the process design and development stage, the thermal runaway process of the exothermic reaction needs to be deeply researched, the thermal runaway mechanism of the exothermic reaction runaway process is researched, and the most effective safety control measures are provided to ensure the safety of the production process.

At present, aiming at the thermal safety research of the chemical reaction process, a test method capable of monitoring the thermal runaway process of the chemical reaction in the whole process and acquiring the thermal runaway parameters under extreme conditions in the thermal runaway process is adopted by domestic and foreign scholars. The test method can test the thermal runaway process of single-phase, two-phase or even three-phase chemical reaction to obtain related thermal runaway parameters, and is a test method which is relatively comprehensive and has the test result closest to the actual working condition. But the problem of quantitative sampling of gas-phase materials with boiling points close to normal temperature in the two-phase and three-phase reaction processes is always a difficult problem which puzzles scholars at home and abroad, such as 1-butene, methylene, liquid ammonia and the like. Because the boiling point is close to the normal temperature, the outlet pressure of the pressure-resistant steel cylinder for storing the materials is generally the saturated vapor pressure of the materials under the normal temperature condition, in the process of adiabatic test sample injection, the materials are directly injected through the pressure-resistant steel cylinder, the highest pressure can only be added to the saturated vapor pressure of the materials under the normal temperature condition, and the pressure of the required material proportion in the process of chemical reaction is generally difficult to reach. Meanwhile, in the process that the materials enter the heat insulation test system from the liquid state to the outlet in the pressure-resistant steel cylinder, the materials are converted into the gas state, the quantification of the materials and the uniform mixing of the materials and other materials entering the heat insulation test system can be influenced, the material proportion is deviated, and the heat insulation calorimetric test result is inconsistent with the actual working condition. In addition, in industrial production and pilot scale processes, materials can be continuously fed after being pretreated by an industrial treatment device such as pressurization or cooling, the laboratory-level adiabatic calorimetry test process is an intermittent reaction process, the materials can only be added once and then begin to react, the materials cannot be reacted in a continuous feeding mode, and the difficulty of quantitative sample introduction is greatly increased. Especially, the materials such as 1-butylene, methylene and the like which are inflammable and explosive under normal temperature condition can bring about the potential safety hazard of explosion by feeding in a pressurization mode. Therefore, it is very necessary to design a quantitative sample injection method for adiabatic calorimetry test, which converts a material with a boiling point close to room temperature and a gas phase at room temperature into a low-temperature liquid.

Disclosure of Invention

One of the purposes of the invention is to provide a quantitative sampling device for converting a normal-temperature gaseous substance into a low-temperature liquid, which can solve the problems that a gas-phase material with a boiling point close to normal temperature is difficult to achieve material proportioning pressure required by a chemical reaction in the process of adiabatic calorimetry test, cannot be uniformly mixed with other materials, and has potential safety hazards of explosion during pressurized feeding.

The technical problems to be overcome by the invention mainly comprise:

1) how to establish a device for converting liquid low-temperature gas-phase materials in a pressure-resistant steel cylinder into a gas state through a pressure reducing valve, then collecting the gas state again, performing low-temperature treatment, and then converting the gas state into a liquid state again;

2) how to establish a device for quantitatively weighing the liquid gas-phase material after low-temperature treatment so as to ensure the accuracy of quantitative sample injection;

3) a device for safely and effectively adding a liquid gas phase material subjected to low-temperature treatment into an adiabatic calorimetry test system.

In order to overcome the technical problems, the invention adopts the following technical scheme:

a quantitative sample introduction device for converting normal-temperature gaseous substances into low-temperature liquid comprises a nitrogen steel cylinder, a gas-phase material steel cylinder, a buffer tank, a pressure piston device, an electronic scale, a low-temperature cooling circulating device, an adiabatic heat measurement testing device, related pipelines and valves, wherein the low-temperature cooling circulating device is used for cooling the gas-phase material entering the buffer tank and converting the gas-phase material into liquid; the mass of the gas-phase material converted into liquid state entering the pressure piston device is recorded by the electronic scale.

Further, sufficient materials recorded by the electronic scale are measured through the adiabatic calorimetry testing device.

Further preferably, the buffer tank comprises a tank wall and a tank body, a cooling coil and a heat insulation material are arranged in the tank wall, and the cooling coil is communicated with the low-temperature cooling circulation device, so that cold circulation of the tank body is formed.

Preferably, the tank body is connected with a first pipeline, a second pipeline and a third pipeline, wherein the first pipeline is connected with the gas-phase material steel cylinder and used for conveying the gas-phase material into the tank body through the first pipeline, the second pipeline is connected with a vacuum pump, the second pipeline is connected with a vacuumizing pipeline valve, and the tank body is vacuumized through the vacuum pump; the third pipeline is connected with the pressure piston device and used for conveying liquid materials formed after cooling through the low-temperature cooling circulating device to the pressure piston device.

Preferably, the electronic scale is located below the pressure piston device, the pressure piston device comprises a piston chamber and a piston rod, the piston rod horizontally reciprocates in the piston chamber, a handle is arranged at the end part of the piston rod far away from the piston chamber, and the material converted into liquid in the buffer tank is pumped into the pressure piston device by pulling the handle.

Preferably, the piston chamber is connected to the nitrogen gas cylinder through a fourth pipeline connected with the piston chamber, a fifth pipeline is connected between the piston chamber and the adiabatic heat testing device, and sufficient materials recorded by the electronic scale are sent to the adiabatic heat testing device for measurement through the fifth pipeline.

Preferably, the adiabatic test device comprises a calorimetric tank, and the calorimetric tank is provided with a calorimetric tank temperature sensor and a calorimetric tank pressure sensor.

Preferably, the buffer tank is provided with a material pressure sensor, a tank wall temperature sensor and a material temperature sensor.

Preferably, the periphery of the piston chamber is coated with a heat insulating material.

Preferably, valves are arranged on the first pipeline, the second pipeline, the third pipeline, the fourth pipeline and the fifth pipeline.

Preferably, the outer wall of the piston chamber is also provided with a coil for cooling and cooling the material, and the coil is connected with the low-temperature cooling circulation device to form a cold circulation.

The invention also aims to provide a quantitative sampling method for converting normal-temperature gaseous substances into low-temperature liquid, which is characterized in that gaseous materials with boiling points close to normal temperature, which are provided by a pressure-resistant steel cylinder, are firstly subjected to low-temperature cooling treatment, and after the materials are completely converted into liquid, the liquid materials are added into a pressure piston device which is subjected to low-temperature cooling treatment, is pressure-resistant and can measure mass through a pipeline with a heat-insulating layer, and the liquid materials are quantitatively, accurately and safely added into an adiabatic calorimetric test system by virtue of the pressure piston device.

In order to achieve the purpose, the invention adopts the following technical scheme:

a quantitative sampling method for converting normal-temperature gaseous substances into low-temperature liquid adopts the quantitative sampling device for converting the normal-temperature gaseous substances into the low-temperature liquid, and comprises the following steps:

s1, firstly, detecting the air tightness of the device, and sending gas-phase materials into the buffer tank after the air tightness is qualified;

s2, starting a low-temperature cooling circulation device, cooling the buffer tank until the temperature in the buffer tank is reduced to the boiling point temperature of the gas-phase material below at least 10 ℃, and at the moment, completely converting the gas-phase material in the buffer tank into a liquid state;

s3, starting the electronic scale and the pressure piston device, pumping all gas-phase materials which are converted into liquid in the buffer tank into the pressure piston device by controlling a piston pull rod and a handle of the pressure piston device, and recording the mass change of the electronic scale;

and S4, stopping the material entering when the record of the electronic scale reaches a certain mass, inputting nitrogen into the pressure piston device, and sending the material into the adiabatic calorimetry testing device for measurement by controlling the nitrogen pressure in the pressure piston device according to the record of the electronic scale.

Further preferably, in step S4, after all the materials in the pressure piston device are fed into the adiabatic testing device, the nitrogen pressure in the pressure piston device is released to the normal pressure.

Compared with the prior art, the invention has the following beneficial technical effects:

(1) the quantitative sampling device for adiabatic calorimetry test for converting gas-phase materials into low-temperature liquid provided by the invention can change liquid low-temperature gas-phase materials in a pressure-resistant steel cylinder into gas state through a pressure reducing valve, then recollect the gas state and carry out low-temperature treatment, quantitatively weigh the liquid gas-phase materials after the low-temperature treatment, safely and effectively add the liquid gas-phase materials into an adiabatic calorimetry test system, and improve the accuracy of adiabatic calorimetry test results of the gas-phase materials.

(2) The invention provides a quantitative sampling method for adiabatic calorimetry test of gas-phase material converted into low-temperature liquid, which comprises the steps of firstly carrying out low-temperature cooling treatment on the gas-phase material with the boiling point close to the normal temperature provided by a pressure-resistant steel cylinder, adding the gas-phase material into a pressure piston device which is subjected to low-temperature cooling treatment, is pressure-resistant and can measure the mass through a pipeline provided with a heat-insulating layer after the material is completely converted into the liquid state, and quantitatively, accurately and safely adding the liquid-phase material into an adiabatic calorimetry test system by means of the pressure piston device.

(3) According to the invention, thermal runaway adiabatic calorimetry test of methyl nitrite decomposition and butene-1 polymerization reaction is carried out in sequence, and the materials can be effectively and accurately quantitatively added into an adiabatic calorimetry test device after being cooled.

(4) The device and the method are particularly suitable for scientific research institutions, colleges, enterprises and design units engaged in the safety of chemical process and chemical process, especially the safety research on chemical reaction thermal runaway, and have considerable application and popularization values in the scientific research institutions, colleges, enterprises and design units engaged in the safety of chemical process and chemical process along with the gradual improvement of the process safety control technology of petrochemical production enterprises in China.

Drawings

The invention is described in detail below with reference to the accompanying drawings:

FIG. 1 is a schematic structural diagram of a quantitative sample injection device for converting a normal-temperature gaseous substance into a low-temperature liquid according to the present invention;

FIG. 2 is a schematic structural view of a buffer tank;

FIG. 3 is a schematic view of the construction of the pressure piston device;

in the figure: 1-nitrogen steel cylinder, 2-gas phase material steel cylinder, 3-nitrogen steel cylinder pressure reducing valve, 4-gas phase material steel cylinder pressure reducing valve, 5-pressure sensor, 6-vacuum pumping pipeline valve, 7-vacuum pump, 8-buffer tank, 9-low temperature cooling circulation device, 10-pressure piston device nitrogen feeding pipeline valve, 11-electronic scale, 12-pressure piston device, 13-pressure piston device gas phase material feeding pipeline valve, 14-adiabatic calorimetric test system feeding pipeline valve, 15-adiabatic calorimetric test device, 16-calorimetric tank temperature sensor, 17-calorimetric tank pressure sensor, 18-material temperature sensor, 19-heat insulation material, 20-cooling coil, 21-material pressure sensor, 22-tank wall temperature sensor, 23-handle, 24-piston pull rod, 25-internal heat insulation material and 26-internal cooling coil.

Detailed Description

The invention provides a quantitative sample introduction device and a sample introduction method for converting a normal-temperature gaseous substance into a low-temperature liquid, and the invention is described in detail below by combining specific embodiments in order to make the advantages and technical scheme of the invention clearer and clearer.

As shown in figure 1, the quantitative sample injection device for converting normal-temperature gaseous substances into low-temperature liquid comprises a nitrogen steel cylinder 1, a gas-phase material steel cylinder 2, a vacuum pump 7, a buffer tank 8, a low-temperature cooling circulating device 9, an electronic scale 11, a pressure piston device 12, an adiabatic heat testing device 15 and related valves, wherein the related valves comprise a nitrogen steel cylinder pressure reducing valve 3, a gas-phase material steel cylinder pressure reducing valve 4, a vacuumizing pipeline valve 6, a pressure piston device nitrogen feeding pipeline valve 10, a pressure piston device gas-phase material feeding pipeline valve 13 and an adiabatic heat testing system feeding pipeline valve 14.

As shown in fig. 2, the specific structure of the buffer tank 8 includes a tank wall and a tank body, a cooling coil 20 and a thermal insulation material 19 are installed in the tank wall, the cooling coil 20 is communicated with a low-temperature cooling circulation device to form a cold circulation to the tank body, the tank body is connected with a material temperature sensor 18 and a material pressure sensor 21 for monitoring the temperature and the pressure of the material in the tank body, respectively, and a tank wall temperature sensor 22 is installed on the tank wall for monitoring the temperature of the tank wall. And the tank wall of the buffer tank is cooled through the low-temperature cooling circulating device, so that the gas phase in the buffer tank is converted into the liquid phase.

Further, a first pipeline, a second pipeline and a third pipeline are connected to the tank body, wherein the first pipeline is connected with a gas-phase material steel cylinder and used for conveying the gas-phase material into the tank body through the first pipeline, a pressure sensor 5 is installed on the first pipeline, the second pipeline is connected with a vacuum pump, a vacuumizing pipeline valve 6 is connected to the second pipeline, and the tank body is vacuumized through the vacuum pump; the third pipeline is connected with the pressure piston device and used for conveying the liquid material formed after cooling through the low-temperature cooling circulating device to the pressure piston device. Corresponding valves are arranged on the corresponding pipelines to control the device, such as a gas material cylinder pressure reducing valve 4 arranged on a first pipeline, and a gas material feeding pipeline valve 13 of a pressure piston device arranged on a third pipeline.

As shown in fig. 3, the electronic scale is located below the pressure piston device, the pressure piston device includes a piston chamber and a piston rod 24, the piston rod 24 performs horizontal reciprocating motion in the piston chamber, a handle 23 is arranged at the end of the piston rod far away from the piston chamber, and the handle is pulled to control the material converted into liquid state in the buffer tank to be pumped into the pressure piston device.

For controlling the temperature of the material in the pressure piston device, the piston chamber is preferably surrounded by an inner insulation 25 and between the piston chamber and the inner insulation there is an inner cooling coil 26.

The piston chamber is connected to the nitrogen steel cylinder through a fourth pipeline connected with the piston chamber, a fifth pipeline is connected between the piston chamber and the adiabatic heat testing device, and sufficient materials recorded by the electronic scale are sent to the adiabatic heat testing device through the fifth pipeline to be measured.

The adiabatic amount testing device comprises a calorimetric tank, a calorimetric tank temperature sensor 16 and a calorimetric tank pressure sensor 17.

The buffer tank is preferably made of a pressure-resistant metal material.

The quantitative sample injection method for converting the normal temperature gaseous substance into the low temperature liquid of the invention is explained in detail below, and the quantitative sample injection device comprises the following steps:

firstly, detecting the air tightness of the device, and feeding gas-phase materials into a buffer tank after the air tightness is qualified;

secondly, starting a low-temperature cooling circulating device, cooling the buffer tank until the temperature in the buffer tank is reduced to the boiling point temperature of the gas-phase material below 10 ℃, and completely converting the gas-phase material in the buffer tank into a liquid state;

thirdly, starting the electronic scale and the pressure piston device, pumping all gas-phase materials converted into liquid in the buffer tank into the pressure piston device by controlling a piston pull rod and a handle of the pressure piston device, and recording the mass change of the electronic scale;

and fourthly, stopping the material entering when the record of the electronic scale reaches a certain mass, inputting nitrogen into the pressure piston device, and sending the material into the adiabatic calorimetry testing device for measurement by controlling the pressure of the nitrogen in the pressure piston device according to the record of the electronic scale.

The sample injection method of the device of the present invention is further described below with reference to specific examples.

Example 1:

firstly, vacuumizing a buffer tank until the reading of a pressure sensor is unchanged, closing a pipeline valve of a vacuum pump, performing air tightness detection, opening a pressure reducing valve switch of a gas-phase material pressure-resistant steel cylinder after the detection is qualified, pumping the low-temperature liquid gas-phase material in the pressure-resistant steel cylinder into the buffer tank by means of negative pressure in the buffer, and closing the pressure reducing valve switch until the reading of the pressure sensor of the buffer tank is unchanged;

starting a low-temperature cooling circulating device, cooling the buffer tank until the temperature of a temperature sensor in the buffer tank is reduced to at least 10 ℃ below the boiling point temperature of the gas-phase material, and ensuring that the gas-phase material in the buffer tank is completely converted into a liquid state;

starting the electronic scale and the pressure piston device, pumping all gas-phase materials which are converted into liquid in the buffer tank into the pressure piston device by controlling a piston pull rod and a handle of the pressure piston device, and recording the mass change of the electronic scale;

when the record of the electronic scale reaches a certain mass, stopping the material from entering, inputting nitrogen into the pressure piston device, and sending the material into the adiabatic calorimetry testing device for measurement by controlling the pressure of the nitrogen in the pressure piston device according to the record of the electronic scale.

Example 2:

firstly, vacuumizing a buffer tank until the reading of a pressure sensor is unchanged, closing a pipeline valve of a vacuum pump, performing air tightness detection, opening a pressure reducing valve switch of a gas-phase material pressure-resistant steel cylinder after the detection is qualified, pumping the low-temperature liquid gas-phase material in the pressure-resistant steel cylinder into the buffer tank by means of negative pressure in the buffer, and closing the pressure reducing valve switch until the reading of the pressure sensor of the buffer tank is unchanged;

starting a low-temperature cooling circulating device, cooling the buffer tank until the temperature of a temperature sensor in the buffer tank is reduced to at least 10 ℃ below the boiling point temperature of the gas-phase material, and ensuring that the gas-phase material in the buffer tank is completely converted into a liquid state;

after the gas phase materials in the buffer tank are completely converted into liquid, opening a valve switch of a feeding pipeline of the electronic balance and the pressure piston device, pulling a piston pull rod handle of the pressure piston device which is made of pressure-resistant metal materials, sealed and provided with a cooling coil and a heat-insulating filling material in the tank wall, wherein the handle can control the gas phase materials which are completely converted into liquid in the buffer tank to be pumped into the pressure piston device, and recording the mass change of the electronic balance. If the mass of the low-temperature gas-phase material extracted once is less than the material amount required by the adiabatic calorimetry test, repeating the operation for multiple times until the mass of the material meets the material amount required by the adiabatic calorimetry test;

when the record of the electronic scale reaches a certain mass, stopping the material from entering, inputting nitrogen into the pressure piston device, and sending the material into the adiabatic calorimetry testing device for measurement by controlling the pressure of the nitrogen in the pressure piston device according to the record of the electronic scale.

Example 3:

firstly, vacuumizing a buffer tank until the reading of a pressure sensor is unchanged, closing a pipeline valve of a vacuum pump, performing air tightness detection, opening a pressure reducing valve switch of a gas-phase material pressure-resistant steel cylinder after the detection is qualified, pumping the low-temperature liquid gas-phase material in the pressure-resistant steel cylinder into the buffer tank by means of negative pressure in the buffer, and closing the pressure reducing valve switch until the reading of the pressure sensor of the buffer tank is unchanged;

starting a low-temperature cooling circulating device, cooling the buffer tank until the temperature of a temperature sensor in the buffer tank is reduced to at least 10 ℃ below the boiling point temperature of the gas-phase material, and ensuring that the gas-phase material in the buffer tank is completely converted into a liquid state;

after the gas phase materials in the buffer tank are completely converted into liquid, opening a valve switch of a feeding pipeline of the electronic balance and the pressure piston device, pulling a piston pull rod handle of the pressure piston device which is made of pressure-resistant metal materials, sealed and provided with a cooling coil and a heat-insulating filling material in the tank wall, wherein the handle can control the gas phase materials which are completely converted into liquid in the buffer tank to be pumped into the pressure piston device, and recording the mass change of the electronic balance. If the mass of the low-temperature gas-phase material extracted once is less than the material amount required by the adiabatic calorimetry test, repeating the operation for multiple times until the mass of the material meets the material amount required by the adiabatic calorimetry test;

and after the material quality meets the material quantity required by the adiabatic calorimetry test, closing a valve switch of a feed pipe line of the pressure piston device, starting an electronic balance for weighing the weight of the pressure piston device, pulling a piston pull rod of the pressure piston device, and opening a pressure reducing valve of a nitrogen steel cylinder and the valve switch of the nitrogen feed pipe line of the pressure piston device. The valve is a three-way valve, and when materials are fed, the nitrogen pressure is controlled, and low-temperature liquid gas-phase materials in the pressure piston device are pumped into a calorimetric tank in an adiabatic calorimetric test system. After the feeding of the materials is finished, the pressure of the nitrogen added into the pressure piston device can be controlled to be released to normal pressure.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto.

The parts which are not described in the invention can be realized by taking the prior art as reference.

It should be noted that: any equivalents or obvious modifications thereof which may occur to persons skilled in the art and which are given the benefit of this description are deemed to be within the scope of the invention.