Desorption gas amount testing device and measurement method

Abstract

The application provides a desorption gas amount testing device and a measuring method. The desorption gas amount testing device comprises: a sample desorption tank for placing a sample to be desorbed; a drainage metering assembly in communication with the sample desorption tank, used for measuring desorption gas generated by the sample to be desorbed; and an exhaust assembly in communication with the drainage metering assembly, used for discharging the desorption gas in the drainage metering assembly. The drainage metering assembly comprises a metering pipe and a first pressure monitoring member arranged at the bottom of the metering pipe, and the first pressure monitoring member can collect pressure values of the water column in real time. According to the technical scheme of the application, the zero-pressure desorption is realized by controlling the drainage rate of the drainage valve through the feedback of the pressure sensor, and the automation of the volume metering is realized based on the change of the water column pressure. The metering method is convenient and fast, has small error and high precision, and can accurately measure the shale field desorption gas amount.

Description

Technical Field

[0001] This invention relates to the field of unconventional oil and gas exploration and development equipment technology, and in particular to a desorption gas volume testing device and calculation method. Background Technology

[0002] Shale gas, as a clean energy source, has seen significant breakthroughs and commercial development in China, attracting widespread attention for its exploration and development. Shale gas content evaluation provides the most direct and crucial parameters for resource assessment and favorable area selection during shale gas exploration and development, demonstrating its irreplaceable role. Gas content testing methods are divided into two categories: direct measurement methods and indirect methods (isothermal adsorption and well logging curve methods). Direct on-site measurement methods are highly reliable, convenient, economical, and fast, making them the preferred choice for shale gas content determination.

[0003] Instruments used for direct on-site gas content determination in drilling coring are based on two principles: one is the mass flow rate principle; the other is the water displacement gas collection method. The former requires the gas composition to be singular or constant during measurement. For different gases, conversion is necessary to obtain the true measured volume. In particular, the gas composition of shale samples changes over time during on-site desorption, and a small amount of water vapor may also be present, leading to significant deviations in the measured values ​​and directly affecting the reliability and accuracy of the results.

[0004] Compared to the former, the traditional water displacement gas collection method can reliably determine the amount of gas desorbed in the field. Currently, instruments based on this principle are widely used in shale field gas content determination. Existing technology discloses a method for determining the volume of desorbed gas in shale using a servo motor drive; however, the servo motor is large and heavy, limiting the number of samples that can be measured per instrument, making it time-consuming and labor-intensive, and unable to quickly, conveniently, and efficiently measure shale samples, thus failing to adapt to the fast pace of field coring. Existing technology also discloses an instrument that combines an electronic pressure sensor with water column height to calculate the actual gas volume, achieving automated volume measurement and high-density core sample determination, characterized by high automation, convenience, and speed. However, the gas desorption process is pressurized desorption; because each sample volume is different, the volume of gas desorbed in a single cycle is different, requiring volume calibration after each desorption cycle, increasing workload. Simultaneously, the desorbed gas needs to drive the water column to generate a pressure difference, leading to certain errors and making it impossible to accurately provide shale gas content data.

[0005] As can be seen from the above, the current devices and methods for measuring the gas content and desorption gas volume in shale fields have certain problems and cannot conveniently and quickly obtain accurate and reliable field data.

[0006] In other words, there is an urgent need to develop a highly automated testing device that can accurately measure the amount of desorbed gas in shale in the field, so as to adapt to the rapid and high-paced evaluation of desorbed gas in field coring. Summary of the Invention

[0007] To address the problems in the prior art, this application proposes a desorption gas volume testing device and calculation method, which features a high degree of automation and the ability to accurately measure the desorption gas volume of shale in the field.

[0008] The desorption gas volume testing device of the present invention includes: a sample desorption container for holding a sample to be desorbed; a drainage metering component connected to the sample desorption container for measuring the desorption gas generated by the sample to be desorbed; and an exhaust component connected to the drainage metering component for discharging the desorption gas in the drainage metering component. The drainage metering component includes a metering tube and a first pressure monitoring element disposed at the bottom of the metering tube, wherein the metering tube is used to display the liquid level height of the water column in the metering tube, and the first pressure monitoring element can collect the pressure value of the water column in real time. In one embodiment, the metering tube is provided with an air inlet and a drain outlet, and the drain metering component further includes: a tee having a first inlet / outlet, a second inlet / outlet, and a third inlet / outlet, the third inlet / outlet being connected to the exhaust component; a first pipeline, one end of which is connected to the sample desorption vessel, and the other end of which is connected to the first inlet / outlet; a first control valve, which is provided on the first pipeline; and a second pipeline, one end of which is connected to the air inlet, and the other end of which is connected to the second inlet / outlet.

[0009] In one embodiment, the drainage metering component further includes: a drainage pipe, one end of which is connected to a drain outlet; and a second control valve disposed on the drainage pipe.

[0010] In one embodiment, a second pressure monitoring device is provided on the first pipeline. The second pressure monitoring device is located between the first control valve and the tee. The second control valve can control the drainage rate of the drainage pipeline according to the pressure value monitored by the second pressure monitoring device.

[0011] In one embodiment, the metering pipe is provided with a water inlet, and the drainage metering component further includes: a water inlet pipe, one end of which is connected to the water inlet; and a third control valve, which is provided on the water inlet pipe.

[0012] In one embodiment, the drainage metering component further includes a water inlet structure connected to the other end of the water inlet pipe.

[0013] In one embodiment, the water inlet structure includes: a water tank; a water inlet pipe, one end of which is connected to the water tank and the other end of which is connected to the other end of the water inlet pipeline; and a water outlet pipe, one end of which is connected to the water tank and the other end of which is connected to the other end of the water outlet pipeline.

[0014] In one embodiment, the exhaust assembly includes: an exhaust pipe, one end of which is connected to a drainage metering assembly; and a fourth control valve disposed on the exhaust pipe.

[0015] In one embodiment, a control component is also included, which is electrically connected to the drainage metering component and the venting component. The present invention also provides a calculation method for calculating the amount of gas desorbed from a sample to be desorbed, comprising the following steps: Step 1: Place the sample to be desorbed into the sample desorption container and heat it for desorption. Step 2: Measure the pressure of the water column in the metering tube using the drainage metering component, and display the water level height in the metering tube. Step 3: Calculate the desorbed gas volume in a single cycle according to the desorbed gas volume calculation formula; Step 4: Calculate the desorbed gas volume in multiple consecutive single cycles based on Step 2 and Step 3. Step 5: The desorbed gas volume in multiple consecutive single cycles is accumulated to obtain the desorbed gas volume of the sample to be desorbed. The above-mentioned technical features can be combined in various suitable ways or replaced by equivalent technical features, as long as the purpose of the present invention can be achieved.

[0016] The desorption gas volume testing device and calculation method provided by this invention have at least the following advantages compared with the prior art: The pressure and liquid level of the water column in the metering tube are measured by a drainage metering component. These values ​​are then substituted into the desorbed gas volume calculation formula to calculate the desorbed gas volume for a single cycle. The calculated desorbed gas volumes over multiple consecutive single cycles are then summed to obtain the total desorbed gas volume of the sample. Compared to desorbed gas volume testing devices and calculation methods in related technologies, the desorbed gas volume testing device in this application does not require consideration of the composition of the desorbed gas. It automates volume measurement through changes in liquid level and pressure. This measurement method is convenient, fast, has low error, and high accuracy, enabling accurate determination of the desorbed gas volume of shale in-situ. Attached Figure Description

[0017] The invention will now be described in more detail with reference to embodiments and the accompanying drawings. Figure 1 A schematic diagram of the desorption gas volume testing device of the present invention is shown; In the accompanying drawings, the same parts use the same reference numerals. The drawings are not to scale.

[0018] Figure label: 10. Sample desorption vessel; 20. Drainage metering assembly; 21. Metering tube; 211. Air inlet; 212. Drain outlet; 213. Water inlet; 22. First pressure monitoring device; 23. T-junction; 231. First inlet / outlet; 232. Second inlet / outlet; 233. Third inlet / outlet; 24. First pipeline; 25. Second pipeline; 26. Drainage pipeline; 27. Second pressure monitoring device; 28. Water inlet pipeline; 29. ​​Water inlet structure; 291. Water tank; 292. Water inlet pipe; 293. Water outlet pipe; 294. Normally open submersible pump; 30. Exhaust assembly; 31. Exhaust pipeline; 41. First control valve; 42. Second control valve; 43. Third control valve; 44. Fourth control valve; 50. Control assembly; 51. Computer control system; 52. Atmospheric environment sensor; 100. Sample to be desorbed. Detailed Implementation

[0019] The invention will now be further described with reference to the accompanying drawings.

[0020] It should be noted that the sample to be desorbed 100 in this application is a shale sample collected from the field, and the desorption gas volume testing device in this application is used for the desorption measurement of the gas content of shale in the field.

[0021] like Figure 1 As shown, the present invention provides a desorption gas volume testing device, which includes a sample desorption tank 10, a water displacement metering component 20 and an exhaust component 30.

[0022] The sample desorption container 10 is used to hold the sample 100 to be desorbed; the drainage metering component 20 is connected to the sample desorption container 10 and is used to measure the desorbed gas generated by the sample 100; the exhaust component 30 is connected to the drainage metering component 20 and is used to discharge the desorbed gas in the drainage metering component 20; the drainage metering component 20 includes a metering tube 21 and a first pressure monitoring element 22 disposed at the bottom of the metering tube 21, wherein the metering tube 21 is used to measure the liquid level height of the water column in the metering tube 21, and the first pressure monitoring element 22 can collect the pressure value of the water column in real time.

[0023] In the above setup, the pressure and liquid level of the water column in the metering pipe 21 are measured by the drainage metering component. These measured values ​​are then substituted into the desorbed gas volume calculation formula to calculate the desorbed gas volume for a single cycle. The calculated desorbed gas volumes from multiple consecutive single cycles are then summed to obtain the desorbed gas volume of the sample 100 to be desorbed. Compared to desorbed gas volume testing devices and calculation methods in related technologies, the desorbed gas volume testing device in this application does not require consideration of the composition of the desorbed gas. It automates volume measurement through changes in liquid level and pressure. This measurement method is convenient, fast, has low error, and high accuracy, enabling accurate determination of the desorbed gas volume of the shale in-situ.

[0024] Specifically, in one embodiment, the first pressure monitoring element 22 employs a pressure sensor.

[0025] Specifically, in one embodiment, the metering tube 21 is a glass tube with a fixed scale, which facilitates intuitive observation of the changes in desorbed gas and liquid level inside the glass tube.

[0026] Specifically, such as Figure 1 As shown, in one embodiment, the glass tube can be disassembled and replaced. For samples with different desorption amounts and desorption rates, a glass tube of appropriate diameter can be used for gas measurement, making the data more accurate and reliable.

[0027] Specifically, such as Figure 1 As shown, in one embodiment, the glass tubes are of types A, B, and C, etc. Glass tube A is connected to a device, while glass tubes B, C, etc., are not connected. In this application, one type can be selected based on the actual degassing volume and rate of the sample 100 to be desorbed.

[0028] Specifically, such as Figure 1 As shown, in one embodiment, the metering tube 21 is provided with an air inlet 211 and a drain outlet 212. The drain metering assembly 20 also includes a tee 23, a first pipeline 24, a first control valve 41, and a second pipeline 25. The tee 23 has a first inlet / outlet 231, a second inlet / outlet 232, and a third inlet / outlet 233, with the third inlet / outlet 233 connected to the exhaust assembly 30. One end of the first pipeline 24 is connected to the sample desorption vessel 10, and the other end is connected to the first inlet / outlet 231. The first control valve 41 is disposed on the first pipeline 24. One end of the second pipeline 25 is connected to the air inlet 211, and the other end is connected to the second inlet / outlet 232. In the above configuration, the first pipe 24 and the second pipe 25 are air inlet pipes. The desorption gas generated in the sample desorption container 10 can be drained and collected through the metering pipe 21 via the air inlet pipes. Specifically, in one embodiment, the first control valve 41 is a normally open electromagnetic valve.

[0029] Specifically, such as Figure 1 As shown, in one embodiment, the drainage metering assembly 20 further includes a drainage pipe 26 and a second control valve 42. One end of the drainage pipe 26 is connected to the drain outlet 212; the second control valve 42 is disposed on the drainage pipe 26.

[0030] In the above configuration, the drain pipe 26 can drain the water squeezed out by the desorbed gas in the metering pipe 21, thereby ensuring that the metering pipe 21 can collect the desorbed gas. This ensures that the drainage and gas collection function of the desorbed gas volume testing device is realized.

[0031] Specifically, in one embodiment, the second control valve 42 is a pressure servo valve.

[0032] Specifically, such as Figure 1 As shown, in one embodiment, a second pressure monitoring element 27 is provided on the first pipeline 24. The second pressure monitoring element 27 is located between the first control valve 41 and the tee 23. The second control valve 42 can control the drainage rate of the drainage pipeline 26 according to the pressure value monitored by the second pressure monitoring element 27.

[0033] In the above configuration, since the second control valve 42 can control the drainage rate of the drainage pipe 26 according to the pressure value monitored by the second pressure monitoring device 27, the liquid in the metering tube 21 is discharged by controlling the opening of the pressure servo valve to different degrees, so that the second pressure monitoring device 27 is in a pressureless state, thereby ensuring that the first pressure monitoring device 22 is not affected by pressurized desorption, accurately collecting the pressure of the water column in the metering tube 21, and thus ensuring that the desorbed gas volume of the sample 100 to be desorbed can be accurately calculated subsequently.

[0034] Specifically, in one embodiment, the second pressure monitoring element 27 employs a pressure sensor.

[0035] Specifically, such as Figure 1 As shown, in one embodiment, the metering pipe 21 is provided with an inlet 213, and the drainage metering component 20 also includes an inlet pipe 28 and a third control valve 43.

[0036] One end of the water inlet pipe 28 is connected to the water inlet 213; the third control valve 43 is installed on the water inlet pipe 28.

[0037] In the above configuration, the water inlet pipe 28 can supply water to the metering pipe 21 to ensure that there is enough water in the metering pipe 21, thereby ensuring that the metering pipe 21 can collect desorbed gas by the method of drainage and gas collection.

[0038] Specifically, in one embodiment, the third control valve 43 is a pressure servo valve.

[0039] Specifically, such as Figure 1 As shown, in one embodiment, the drainage metering component 20 further includes a water inlet structure 29, which is connected to the other end of the water inlet pipe 28.

[0040] In the above configuration, the water inlet structure 29 can provide a water source for the metering pipe 21 to ensure that the water inlet pipe 28 can supply enough water into the metering pipe 21, thereby ensuring that the metering pipe 21 can collect desorbed gas by the method of drainage and gas collection.

[0041] Specifically, such as Figure 1 As shown, in one embodiment, the water inlet structure 29 includes a water tank 291, a water inlet pipe 292, and a water outlet pipe 293.

[0042] One end of the inlet pipe 292 is connected to the water tank 291, and the other end is connected to the other end of the inlet pipe 28; one end of the outlet pipe 293 is connected to the water tank 291, and the other end is connected to the other end of the drain pipe 26.

[0043] Specifically, such as Figure 1 As shown, in one embodiment, the water outlet pipe 293 is connected to the drainage pipe 26.

[0044] It should be noted that when water enters through the inlet structure 29, the second control valve 42 is in the closed state and the third control valve 43 is in the open state, pressurizing the water tank 291 to inject water into the metering pipe 21. When water enters through the inlet structure 29, the second control valve 42 is in the open state and the third control valve 43 is in the closed state.

[0045] Specifically, such as Figure 1 As shown, in one embodiment, a normally open submersible pump 294 is provided in the water tank 291 to pump water from the water tank 291 into the metering pipe 21.

[0046] Specifically, such as Figure 1 As shown, in one embodiment, the exhaust assembly 30 includes an exhaust pipe 31 and a fourth control valve 44.

[0047] One end of the exhaust pipe 31 is connected to the drainage metering component 20, and the fourth control valve 44 is installed on the exhaust pipe 31.

[0048] It should be noted that the exhaust pipe 31 can pass the relatively pure desorption gas collected in the metering pipe 21 into the external desorption gas collection device.

[0049] Specifically, in one embodiment, the fourth control valve 44 is an electromagnetic venting valve.

[0050] Specifically, such as Figure 1 As shown, in one embodiment, the desorption gas volume testing device further includes a control component 50, which is electrically connected to the drainage metering component 20 and the exhaust component 30.

[0051] Specifically, such as Figure 1 As shown, in one embodiment, the control component 50 includes a computer control system 51 and an atmospheric environment sensor 52.

[0052] The atmospheric environment sensor 52 employs a set of temperature and pressure sensors. It is electrically connected to the computer control system 51 to provide feedback on the pressure and temperature of the external environment. The computer control system 51 is also electrically connected to the first control valve 41, the second control valve 42, the third control valve 43, the fourth control valve 44, the first pressure monitoring element 22, and the second pressure monitoring element 27. It can receive pressure information from the first pressure monitoring element 22 and the second pressure monitoring element 27, and can also control the operation of the aforementioned control valves.

[0053] The present invention also provides a calculation method for calculating the amount of gas desorbed from a sample 100 to be desorbed, comprising the following steps: Step 1: Place the sample to be desorbed into the sample desorption container and heat it for desorption. Step 2: Measure the pressure of the water column in the metering tube using the drainage metering component, and display the water level height in the metering tube. Step 3: Calculate the desorbed gas volume in a single cycle according to the desorbed gas volume calculation formula; Step 4: Calculate the desorbed gas volume in multiple consecutive single cycles based on Step 2 and Step 3. Step 5: The desorbed gas volume in multiple consecutive single cycles is accumulated to obtain the desorbed gas volume of the sample to be desorbed.

[0054] It should be noted that, assuming the desorption time of the sample 100 to be desorbed is T (the time period from the start of gas production to the end of gas production), T includes multiple consecutive time periods T1 (single period), for example, T1 can be set to 30 seconds. The desorption gas volume testing device of this application can calculate the desorption gas volume within multiple consecutive single periods, and the desorption gas volume of the sample 100 to be desorbed can be obtained by summing the desorption gas volumes within multiple consecutive single periods.

[0055] The following is combined Figure 1 Here is a detailed description of a complete embodiment of this application: The present invention includes a sealed sample desorption vessel 10, in which a cored shale sample is placed and heated for desorption. An electromagnetic normally open valve is connected to the upper end of the sample desorption vessel 10 to control the outflow and shut-off of the desorbed gas in the sample desorption vessel 10. A three-way valve 23 is connected after the electromagnetic normally open valve, which is connected to the sample desorption vessel 10, the metering tube 21 and the electromagnetic venting valve respectively. The upper end of the glass tube is connected to an electromagnetic venting valve, which is used to release the desorbed gas collected in the sample desorption vessel 10 within the glass tube. A water column bottom pressure sensor is installed at the bottom of the glass tube to measure the pressure of the water column inside the glass tube in real time. The lower end of the glass tube is connected to a drainage pressure servo valve, controlled by a gas pressure sensor. The valve opens to varying degrees depending on the magnitude of the gas pressure detected by the gas pressure sensor, thereby controlling the outflow of liquid from the glass tube. The other end of the drainage pressure servo valve is connected to a connecting pipe (outlet pipe 293) that communicates with the bottom of the water tank 291. When gas from the sample desorption vessel 10 enters the glass tube, the drainage pressure servo valve opens, and the liquid in the glass tube flows into the water tank 291 through the connecting pipe, achieving pressureless drainage and gas collection.

[0056] The liquid inside the glass tube does not completely fill the tube. The liquid level is controlled by a high-precision water column bottom pressure sensor (first pressure monitoring element 22) installed at the bottom. When the liquid level in the glass tube reaches the set maximum height D, the water column pressure at this time is calibrated to be P. max When the liquid level in the glass tube reaches the set minimum height E, the calibrated water column pressure is P. min The liquid level difference between the highest (D) and lowest (E) liquid levels inside the glass tube is calibrated as H. max Furthermore, since the inner diameter and area S of the glass tube are fixed, the maximum volume of liquid that can be discharged from the glass tube in a single cycle is also fixed, i.e., V. max =H max S.

[0057] When the desorbed gas in the glass tube reaches the minimum liquid level E, the computer control system 51 automatically closes the normally open electromagnetic valve and opens the electromagnetic venting valve to release the gas. At the same time, it controls the pressure servo valve for water inlet at the lower end of the glass tube to open, and pumps water from the water tank 291 into the glass tube through the connecting pipe via the normally open submersible pump 294 immersed in the water tank 291, so that the liquid level in the glass tube is restored to the maximum liquid level D, the electromagnetic venting valve is closed, and the normally open electromagnetic valve is opened.

[0058] Therefore, through the above-mentioned device, the present invention realizes gas collection by the drainage gas collection method. The desorbed gas pressure sensor is linked with the pressure servo valve to avoid measurement under pressure. At the same time, there is no need to consider the gas composition. The volume of desorbed gas is directly measured by the reading of the pressure sensor at the bottom of the water column. The data error is small, the reliability is high, and the data is stable and reliable.

[0059] A gas pressure sensor is installed between the electromagnetic normally open valve and the three-way valve 23. The purpose of the gas pressure sensor is to measure the pressure of the gas flowing through it. When the pressure is greater than 0, the valve opens to varying degrees depending on the desorbed gas pressure at the sensor, eliminating errors in the data from the water column bottom pressure sensor caused by gas pressure within the glass tube. Therefore, by directly applying the formula to the actual water column pressure data obtained from the bottom pressure sensor, the gas desorption amount is obtained, resulting in more stable and reliable data. The computer control system 51 includes an atmospheric environment sensor 52. The atmospheric environment sensor 52 collects ambient temperature and atmospheric pressure values. Simultaneously, the computer control system 51 integrates and controls the electromagnetic normally open valve, electromagnetic vent valve, water column bottom pressure sensor, pressure servo valves for inlet and outlet drainage, and the gas pressure sensor, collecting real-time data. Therefore, the automated control required by the device of this invention is achieved.

[0060] In an alternative embodiment not shown in the accompanying drawings, each glass tube is equipped with a separate solenoid normally open valve, a solenoid vent valve, a water column bottom pressure sensor, a drain and inlet pressure servo valve, and a gas pressure sensor, forming a separate metering unit for a single desorbed sample 100. The water tank 291 can be connected to multiple metering units via a connecting pipe and a normally open submersible pump 294. This design enables simultaneous analysis of multiple desorbed samples 100, facilitating efficient and convenient high-density, fast-paced coring evaluation.

[0061] The following will describe in detail the method for measuring desorption in the field using an on-site desorption measurement device, including the following steps: Step A: Instrument initialization, the computer automatically controls the opening of the inlet water pressure servo valve to make the water level in the glass tube calibrated to the highest liquid level height D value, the electromagnetic vent valve is closed, and the computer control system records the temperature and pressure at the atmospheric environment sensor. Step B: Place the shale sample in a sealed sample desorption vessel. After heating, the desorbed gas enters the glass tube through the electromagnetic normally open valve and the three-way valve. Step C: The gas pressure sensor located between the normally open electromagnetic valve and the three-way valve collects the desorbed gas pressure in real time. When the real-time pressure P in the glass tube... 气 When the pressure is greater than 0, the computer automatically controls the opening of the pressure servo valve at the lower end of the glass tube for drainage. The opening of this valve, at varying degrees, controls the liquid in the glass tube to enter the connecting pipe and then drain into the water tank, keeping the gas pressure sensor in a depressurized state. At this time, the pressure sensor at the bottom of the water column collects the water column pressure P in real time. 水 ; Step D: When the liquid level in the glass tube drops to the preset minimum liquid level height E, P 水 =Pmin At this time, the computer automatically controls the closing of the normally open electromagnetic valve and the opening of the electromagnetic vent valve to release air. At the same time, it controls the opening of the pressure servo valve for water inlet at the lower end of the glass tube, and pumps the liquid in the water tank into the glass tube through the normally open submersible pump. Step E: When the liquid level in the glass tube returns to the set maximum liquid level D and the pressure value at the gas pressure sensor is 0, restore the initial state, close the electromagnetic venting valve, open the electromagnetic normally open valve, and start the next desorption cycle. Step F: Calculate the desorbed gas volume based on the real-time pressure measured by the pressure sensor at the bottom of the water column.

[0062] The following will explain in detail how to calculate the desorbed gas volume in step F.

[0063] Based on the data from steps A and C, determine the fixed volume V released during the venting of the glass tube. max The value of V max =H max S (Formula 1) Among them, H max To calibrate the maximum liquid level difference H in the glass tube max S is the area of ​​the cross-section inside the glass tube; Assuming that at any two times T1 and T2, the water column pressure readings are P1 and P2 respectively, and the glass tube discharges gas for n single cycles during the interval between the two measurements, then the amount of desorbed gas during the interval between the two measurements is: V=(P1-P min +P max -P2)S / ρg +n H max S (Formula 2); Converted to standard state: V 标 =P 环 V / P 标 (Formula 3); Among them, P 标 P is the standard atmospheric pressure value. max P min The pressure values ​​at the pressure sensor at the bottom of the water column, P, are the preset maximum (D) and minimum (E) heights of the liquid level in the glass tube, respectively. 环 ρ is the ambient atmospheric pressure value when the instrument is working, S is the area of ​​the cross-section inside the glass tube, ρ is the liquid density in the glass tube, and g is the gravitational acceleration value.

[0064] It should be noted that combining formulas 1 to 3 yields the desorption gas volume calculation formula in this application: V 标 =P 环 [(P1-P min +P max -P2)S / ρg +nVmax ] / P 标 Therefore, the final V is 标 This is the desorbed gas volume under standard conditions obtained within the two measurement intervals. Then, the desorbed gas volume in multiple consecutive single periods is calculated; finally, the desorbed gas volumes in multiple consecutive single periods are summed to obtain the desorbed gas volume of the sample 100 to be desorbed.

[0065] In the description of this invention, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "rear", "inner", "outer", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0066] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A calculation method, characterized in that, The desorption gas volume testing device used in the calculation method includes: a sample desorption container for holding the sample to be desorbed; a drainage metering component connected to the sample desorption container for measuring the desorption gas generated by the sample to be desorbed; and an exhaust component connected to the drainage metering component for discharging the desorption gas within the drainage metering component. The drainage metering component includes a metering tube and a first pressure monitoring element disposed at the bottom of the metering tube. The metering tube displays the liquid level of the water column within it, and the first pressure monitoring element can collect the pressure value of the water column in real time. The metering tube is provided with a water inlet. The metering component also includes a water inlet structure, which comprises: a water tank; a normally open submersible pump installed in the water tank for pumping water from the tank into a metering pipe; the metering pipe having an air inlet and a drain outlet; the drainage metering component further includes: a drain pipe, one end of which is connected to the drain outlet; a second control valve installed on the drain pipe; a water inlet pipe, one end of which is connected to the water inlet; and a third control valve installed on the water inlet pipe; the water inlet structure also includes: a water inlet pipe, one end of which is connected to the water tank and the other end of which is connected to the other end of the water inlet pipe; and a water outlet pipe, one end of which is connected to the water tank and the other end of the drain pipe. The calculation method is used to calculate the amount of desorbed gas in the sample to be desorbed, and includes the following steps: Step 1: Place the sample to be desorbed into the sample desorption container for heating and desorption. Step 2: Measure the pressure of the water column in the metering tube using the drainage metering component, and display the water level height in the metering tube. Step 3: The desorption time of the sample to be desorbed is T, which includes multiple consecutive time periods T1. Calculate the desorbed gas volume within a single period according to the desorbed gas volume calculation formula. Step 4: Calculate the desorbed gas volume within multiple consecutive single periods based on Steps 2 and 3. Step 5: Sum the desorbed gas volumes within multiple consecutive single periods to obtain the total desorbed gas volume of the sample to be desorbed. The metering tube is a glass tube with a fixed scale. The upper end of the glass tube is connected to an electromagnetic venting valve, and the lower end of the glass tube is connected to a pressure servo valve for drainage. It is controlled by a gas pressure sensor and can open the valve to different degrees according to the gas pressure analyzed by the gas pressure sensor, thereby controlling the liquid flow out of the glass tube. When the desorbed gas in the glass tube reaches the minimum liquid level E, the computer control system automatically closes the normally open solenoid valve and opens the solenoid vent valve to release the gas. At the same time, it controls the pressure servo valve for water inlet at the lower end of the glass tube to open, and pumps water from the water tank into the glass tube through the connecting pipe via a normally open submersible pump immersed in the water tank, so that the liquid level in the glass tube returns to the maximum liquid level D. Then, the solenoid vent valve closes and the normally open solenoid valve opens. When the liquid level in the glass tube returns to the set maximum liquid level D and the pressure value at the gas pressure sensor is 0, the initial state is restored, the solenoid vent valve closes, the normally open solenoid valve opens, and the next desorption cycle begins. The fixed volume V released during the venting of the calibrated glass tube max The value of V max =H max S; where H max To calibrate the maximum liquid level difference H in the glass tube max Let S be the area of ​​the cross-section inside the glass tube; at any two times T1 and T2, the water column pressure readings are P1 and P2 respectively. If the glass tube discharges gas for n single cycles during the interval between the two measurements, then the amount of desorbed gas during the interval is: V = (P1 - P2) / (T1 - T2) / (T1 - T2) / (T1 - T2) / (T2 ... min +P max -P2)S / ρg+nH max S; converted to standard state: V 标 =P 环 V / P 标 Where P represents the standard atmospheric pressure value, P max P min The values ​​are the pressure at the bottom of the water column pressure sensor when the liquid level in the glass tube is preset to the maximum and minimum heights, respectively. P_ring represents the ambient atmospheric pressure during instrument operation, S is the cross-sectional area of ​​the glass tube, ρ is the liquid density in the glass tube, and g is the acceleration due to gravity. The desorbed gas volume is calculated using the formula: V 标 =P 环 [(P1-P min +P max -P2)S / ρg+nV max ] / P 标 The final V standard is the amount of desorbed gas obtained under standard conditions within the two measurement intervals.

2. The calculation method according to claim 1, characterized in that, The drainage metering component also includes: The three-way valve has a first inlet / outlet, a second inlet / outlet, and a third inlet / outlet, wherein the third inlet / outlet is connected to the exhaust assembly. The first pipeline has one end connected to the sample desorption vessel and the other end connected to the first inlet and outlet. The first control valve is installed on the first pipeline; The second pipeline has one end connected to the air inlet and the other end connected to the second inlet / outlet.

3. The calculation method according to claim 2, characterized in that, A second pressure monitoring device is installed on the first pipeline. The second pressure monitoring device is located between the first control valve and the three-way valve. The second control valve can control the drainage rate of the drainage pipeline according to the pressure value monitored by the second pressure monitoring device.

4. The calculation method according to claim 3, characterized in that, The water inlet structure is connected to the other end of the water inlet pipe.

5. The calculation method according to claim 1, characterized in that, The exhaust assembly includes: The exhaust pipe is connected at one end to the drainage metering component. The fourth control valve is located on the exhaust pipe.

6. The calculation method according to any one of claims 1 to 5, characterized in that, It also includes a control component that is electrically connected to the drainage metering component and the exhaust component.

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