Infrared gas analyzer environmental pressure compensation device and compensation method under constant temperature condition

Abstract

The application discloses an environmental pressure compensation device of an infrared gas analyzer under constant temperature conditions, which comprises a sealed box body, a hollow cylindrical working gas chamber shell is arranged in the sealed box body, the upper surface of the working gas chamber shell is attached to the top end upper surface of the sealed box body, the lower surface of the working gas chamber shell is attached to the lower surface of the sealed box body, the working gas chamber shell divides the inside of the sealed box body into a working gas chamber and an adjusting gas chamber, and the infrared gas analyzer is arranged in the working gas chamber. The application also provides an environmental pressure compensation method of the infrared gas analyzer under constant temperature conditions. The environmental pressure compensation device and the compensation method of the infrared gas analyzer under constant temperature conditions reduce the influence of temperature and pressure changes in the environment of the infrared gas analyzer on the measurement accuracy, and provide a theoretical method and technical equipment for industrial environmental gas concentration measurement.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas sensor monitoring, and particularly to an environmental pressure compensation device and method for infrared gas analyzer under constant temperature conditions. BACKGROUND

[0002] The detection accuracy of a gas sensor is usually related to pressure under constant temperature conditions, and the instability of the pressure leads to a decrease in the accuracy of the sensor. When infrared light passes through a gas, the intensity of the incident light becomes weaker than that of the outgoing light, and the concentration of the gas is detected by measuring the energy difference. The compensation method commonly used at present is to perform corresponding algebraic operations on the collected gas concentration by using a mathematical model to output the corresponding gas concentration. When the atmospheric pressure changes, the gas in a unit volume is compressed, that is, the intermolecular distance of the gas changes, so that the energy absorbed by the infrared light increases, but the concentration of the gas does not change. Therefore, the measured concentration has a large deviation compared with the true value. When the pressure at the same place often changes in a large range or the pressure at the calibration site of the sensor and the pressure at the use site change greatly, the infrared gas analyzer needs to be pressure corrected, and the existing pressure compensation method cannot accurately analyze the concentration of the gas component to be detected. SUMMARY

[0003] In order to solve the above technical problems, the present application aims to provide an environmental pressure compensation device and method for infrared gas analyzer under constant temperature conditions.

[0004] To achieve the above-mentioned purpose, the technical solution provided by the present application is as follows: an environmental pressure compensation device for infrared gas analyzer under constant temperature conditions, comprising a sealed box body, a hollow cylindrical working gas chamber shell is arranged in the sealed box body, the upper surface of the working gas chamber shell is attached to the top end of the upper surface of the sealed box body, the lower surface of the working gas chamber shell is attached to the lower surface of the sealed box body, the working gas chamber shell separates the inside of the sealed box body into a working gas chamber and an adjusting gas chamber, and an infrared gas analyzer is placed in the working gas chamber.

[0005] A first pressure sensor and a pressure regulating device are arranged in the adjusting gas chamber, the first pressure sensor is used to measure the pressure in the adjusting gas chamber, and the pressure regulating device is used to regulate the pressure in the working gas chamber.

[0006] A temperature sensor is further arranged in the adjusting gas chamber, the temperature sensor is used to measure the environmental temperature of the adjusting gas chamber, a constant temperature control device and a second pressure sensor are installed on the working gas chamber shell, the constant temperature control device is used to regulate the temperature in the adjusting gas chamber and the working gas chamber, and the second pressure sensor is used to measure the pressure in the working gas chamber.

[0007] The pressure regulating device and the constant temperature control device are connected to a PLC terminal control device through wires.

[0008] The signal transmission device is connected with the first pressure sensor, the second pressure sensor and the temperature sensor through wires, and is signal-connected with the PLC terminal control device; the signal transmission device receives the pressure data measured by the first pressure sensor and the second pressure sensor and the temperature data measured by the temperature sensor, and transmits the pressure data and the temperature data to the PLC terminal control device; the PLC terminal control device controls the pressure regulating device to act to adjust the gas pressure in the working gas chamber to reach a standard pressure state, and controls the constant temperature control device to act to adjust the temperature in the working gas chamber and the adjusting gas chamber to reach a constant temperature state.

[0009] Further, the closed box body is a hollow cylindrical structure.

[0010] Further, the adjusting gas chamber is under room temperature and normal pressure conditions, and the adjusting gas in the adjusting gas chamber is air.

[0011] Further, the pressure regulating device comprises an air charging pump, an air exhausting pump, an air charging pump driving motor and an air exhausting pump driving motor, the air charging pump driving motor and the air exhausting pump driving motor are connected with the PLC terminal control device respectively, the air charging pump driving motor is connected with the air charging pump, the air exhausting pump driving motor is connected with the air exhausting pump, and the air charging pump and the air exhausting pump are connected with the working gas chamber respectively for air charging and air exhausting to the working gas chamber, so that the pressure of the working gas chamber is adjusted.

[0012] Further, the constant temperature control device comprises a heating device and a refrigerating device, and the heating device and the refrigerating device are connected with the PLC terminal control device respectively.

[0013] Further, the working gas chamber is further provided with a to-be-measured gas inlet pipe and a to-be-measured gas outlet pipe, the to-be-measured gas inlet pipe and the to-be-measured gas outlet pipe are embedded in the infrared gas analyzer, an inlet valve is arranged on the to-be-measured gas inlet pipe, an outlet valve is arranged on the to-be-measured gas outlet pipe, and the inlet valve and the outlet valve are connected with the PLC terminal control device respectively.

[0014] Further, the standard pressure state is that the pressure of the working gas chamber reaches a standard state pressure value P0 set by the second pressure sensor, and the constant temperature state is that the temperature data measured by the temperature sensor reaches a constant temperature control value T0 set by the temperature sensor.

[0015] Further, the standard state pressure value P0 is 100 kpa, and the constant temperature control value T0 is 45 DEG C.

[0016] The application also provides an infrared gas analyzer environmental pressure compensation method under constant temperature conditions, which is realized by using the infrared gas analyzer environmental pressure compensation device under constant temperature conditions, and comprises the following steps:

[0017] Step 1, the pressure value P of the adjusting chamber is measured by adjusting the first pressure sensor in the chamber c ;

[0018] Step 2, when starting to measure, the standard state pressure value P0 of the second pressure sensor in the working chamber and the constant temperature control value T0 of the temperature sensor are set first;

[0019] Step 3, the first pressure sensor measures the pressure value P of the adjusting chamber c , the second pressure sensor transmits the standard state pressure value P0 to the signal transmission device, and the signal transmission device transmits the obtained pressure value P c of the adjusting chamber and the standard state pressure value P0 to the PLC terminal control device;

[0020] The temperature sensor transmits the measured ambient temperature data and the constant temperature control value T0 set in step 2 to the signal transmission device, and the signal transmission device transmits the ambient temperature data and the constant temperature control value T0 to the PLC terminal control device;

[0021] Step 4, after obtaining the pressure value P c of the adjusting chamber and the standard state pressure value P0, the PLC terminal control device calculates the required adjusting gas volume V, and the PLC terminal control device controls the air pump or air pump in the adjusting chamber to work to adjust the pressure in the working chamber to P0;

[0022] At the same time, the temperature in the working chamber and the adjusting chamber is adjusted by the constant temperature control device, and when the temperature reaches the constant temperature state, i.e. the temperature data measured by the temperature sensor reaches the constant temperature control value T0, the to-be-measured gas can be input to the infrared gas analyzer through the to-be-measured gas inlet pipe for gas concentration measurement;

[0023] Step 5, after the measurement is completed, the gas is exhausted through the to-be-measured gas outlet pipe.

[0024] Further, in step 4, the calculation process of the PLC terminal control device is as follows:

[0025] Step a, first determine the required compensation pressure difference according to formula (1):

[0026] ΔP = P c -P0 (1)

[0027] Where: ΔP is the required compensation pressure difference, kPa; P0 is the set standard state pressure value of the second pressure sensor; P c is the pressure value of the adjusting chamber measured by the first pressure sensor, kPa;

[0028] Step b, calculate the required adjusting gas volume V according to formula (8):

[0029]

[0030] V = C * V 3 ; C is the molar concentration of the adjusting gas, mol / L; V t is the standard volume of the adjusting gas, L / mol, R is the ideal gas constant, T is the temperature in Kelvin, K, T = 273.15 + T0, T0 is the constant temperature control value of the temperature sensor, ℃;

[0031] Step c, the air charging pump or air exhaust pump is controlled by the PLC terminal control device to charge or exhaust the working gas chamber according to the required adjusting gas volume V calculated in step b, so as to adjust the pressure of the working gas chamber to P0.

[0032] Compared with the prior art, the beneficial results of the present application are as follows:

[0033] The present application is an environmental pressure compensation device and method for an infrared gas analyzer under constant temperature conditions. The working gas chamber is separated from the external environment by the adjusting chamber, which avoids the influence of external environmental components such as moisture and dust on the measurement accuracy of the infrared gas analyzer, and the adjusting chamber simulates the external environment to make the working gas chamber work in a more accurate pressure and temperature environment. The infrared gas analyzer is placed in the working gas chamber, and the standard state pressure value P0 of the second pressure sensor of the working gas chamber and the constant temperature control value T0 of the temperature sensor are set. The pressure of the working gas chamber is adjusted by the pressure regulating device in the adjusting chamber, and the temperature in the working gas chamber and the adjusting chamber is adjusted by the constant temperature control device. When the temperature reaches a constant temperature state, i.e. the temperature data measured by the temperature sensor reaches the constant temperature control value T0, the measured gas can be input to the infrared gas analyzer through the measured gas inlet pipe for gas concentration measurement. Further, pressure compensation under constant temperature conditions is realized, so that the infrared gas analyzer in the working gas chamber works under standard pressure.

[0034] The environmental pressure compensation device and method for an infrared gas analyzer under constant temperature conditions of the present application reduce the influence of temperature and pressure changes in the environment of the infrared gas analyzer on its measurement accuracy, and provide a theoretical method and technical equipment for industrial environmental gas concentration measurement. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a structural schematic diagram of the environmental pressure compensation device for an infrared gas analyzer under constant temperature conditions of the present application;

[0036] Figure 2 is a top view of Figure 1 ;

[0037] Figure 3 isFigure 1 side view of the closed box body;

[0038] Figure 4 is a control flow chart of the PLC terminal control device of the present application;

[0039] In the figure: 1, closed box body; 2, working gas chamber shell; 3, working gas chamber; 4, adjusting gas chamber; 5, infrared gas analyzer; 6, gas inlet pipe of gas to be measured; 7, air charging pump; 8, air exhausting pump; 9, air charging pump driving motor; 10, air exhausting pump driving motor; 11, temperature sensor; 12, constant temperature control device; 121, heating device; 122, refrigerating device; 13, second pressure sensor; 14, PLC terminal control device; 15, signal transmission device; 16, first pressure sensor; 17, gas outlet pipe of gas to be measured; 18, inlet valve; 19, outlet valve. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0041] Embodiment one

[0042] With reference to Figures 1-4 , the constant temperature condition infrared gas analyzer environmental pressure compensation device comprises a closed box body 1, a hollow cylindrical working gas chamber shell 2 is arranged in the closed box body 1, the upper surface of the working gas chamber shell 2 is attached to the top end upper surface of the closed box body 1, the lower surface of the working gas chamber shell 2 is attached to the lower surface of the closed box body 1, the working gas chamber shell 2 divides the inside of the closed box body 1 into a working gas chamber 3 and an adjusting gas chamber 4, and an infrared gas analyzer 5 is placed in the working gas chamber 3;

[0043] A first pressure sensor 16 and a pressure regulating device are arranged in the adjusting gas chamber 4, the first pressure sensor 16 is used for measuring the pressure in the adjusting gas chamber 4, and the pressure regulating device is used for regulating the pressure in the working gas chamber 3;

[0044] A temperature sensor 11 is further arranged in the adjusting gas chamber 4, the temperature sensor 11 is used for measuring the environmental temperature of the adjusting gas chamber 4 (the temperature of the working gas chamber 3 is the same as that of the adjusting gas chamber 4), a constant temperature control device 12 and a second pressure sensor 13 are installed on the working gas chamber shell 2, the constant temperature control device 12 is used for regulating the temperature in the adjusting gas chamber 4 and the working gas chamber 3, and the second pressure sensor 13 is used for measuring the pressure in the working gas chamber 3;

[0045] The pressure regulating device and the constant temperature control device 12 are connected with the PLC terminal control device 14 through wires.

[0046] The signal transmission device 15 is arranged at the bottom of the closed box 1, and is connected with the first pressure sensor 16, the second pressure sensor 13 and the temperature sensor 11 through wires, and is signal connected with the PLC terminal control device 14. The signal transmission device 15 receives the pressure data measured by the first pressure sensor 16 and the second pressure sensor 13 and the temperature data measured by the temperature sensor 11, and transmits the data to the PLC terminal control device 14. The PLC terminal control device 14 controls the pressure regulating device to adjust the pressure in the working gas chamber 3 to reach the standard pressure state, and controls the constant temperature control device 12 to adjust the temperature in the working gas chamber 3 and the adjusting gas chamber 4 to reach the constant temperature state.

[0047] The closed box 1 is a hollow cylindrical structure.

[0048] The adjusting gas chamber 4 is under room temperature and normal pressure, and the adjusting gas in the adjusting gas chamber 4 is air.

[0049] The pressure regulating device includes an air charging pump 7, an air exhausting pump 8, an air charging pump driving motor 9 and an air exhausting pump driving motor 10. The air charging pump driving motor 9 and the air exhausting pump driving motor 10 are connected with the PLC terminal control device 14 respectively. The air charging pump driving motor 9 is connected with the air charging pump 7, and the air exhausting pump driving motor 10 is connected with the air exhausting pump 8. The air charging pump 7 and the air exhausting pump 8 are connected with the working gas chamber 3 respectively, for charging and exhausting air to the working gas chamber 3, so as to adjust the pressure in the working gas chamber 3.

[0050] The constant temperature control device 12 includes a heating device 121 and a refrigerating device 122, which are connected with the PLC terminal control device respectively.

[0051] The working gas chamber 3 is also provided with a to-be-measured gas inlet pipe 6 and a to-be-measured gas outlet pipe 17, which are embedded in the infrared gas analyzer 5. The to-be-measured gas inlet pipe 6 is provided with an inlet valve 18, and the to-be-measured gas outlet pipe 17 is provided with an outlet valve 19. The inlet valve 18 and the outlet valve 19 are connected with the PLC terminal control device 14 respectively.

[0052] The standard pressure state is that the pressure in the working gas chamber 3 reaches the standard state pressure value P0 set by the second pressure sensor 13, and the constant temperature state is that the temperature data measured by the temperature sensor 11 reaches the constant temperature control value T0 set by the temperature sensor 11.

[0053] The standard state pressure value P0 is 100 kpa, and the constant temperature control value T0 is 45℃.

[0054] In this embodiment, the height of the closed box 1 is 200mm, the volume of the working gas chamber 3 is 0.01m 3 , and the volume of the adjusting gas chamber 4 is 0.0424m 3 .

[0055] Working principle: the PLC terminal control device 14 controls the air exhaust pump driving motor 10 to drive the air exhaust pump 8 to exhaust the working gas chamber 3 or controls the air filling pump driving motor 9 to drive the air filling pump 7 to fill the working gas chamber 3 according to the pressure in the adjusting gas chamber 4 measured by the first pressure sensor 16, so as to change the gas pressure in the working gas chamber 3, so that the working gas chamber 3 reaches the standard pressure state, and at the same time, the PLC terminal control device 14 controls the constant temperature control device 12 to work according to the temperature data measured by the temperature sensor 11, so as to control the temperature in the adjusting gas chamber 4 and the working gas chamber 3 to reach the constant temperature state, at this time, the PLC terminal control device 14 controls to close the pressure regulating device and the constant temperature control device 12, and at the same time, controls the air inlet valve 18 to open, and the measured gas enters the infrared gas analyzer 5 to start the gas concentration measurement, and after the measurement is completed, the air outlet valve 19 is opened to discharge the gas.

[0056] Embodiment two

[0057] The infrared gas analyzer environmental pressure compensation method under constant temperature conditions is realized by using the infrared gas analyzer environmental pressure compensation device under constant temperature conditions in the embodiment one, wherein the range of the infrared gas analyzer 5 in this embodiment is 100ppm, and the preset measurement concentration of the measured gas is 2%, 4%, 6%, 8% and 10% of CH4 gas, and the steps include:

[0058] Step 1: the pressure value P c of the adjusting gas chamber 4 is measured by the first pressure sensor 16 in the adjusting gas chamber 4;

[0059] Step 2: when starting to measure, the standard state pressure value P0 of the second pressure sensor 13 in the working gas chamber 3 and the constant temperature control value T0 of the temperature sensor 11 are set, in this embodiment, P0=100kPa and T0=45℃;

[0060] Step 3: the first pressure sensor 16 transmits the measured pressure value P c of the adjusting gas chamber 4 to the signal transmission device 15, and the second pressure sensor 13 transmits the standard state pressure value P0 to the signal transmission device 15, and the signal transmission device 15 transmits the obtained pressure value P c of the adjusting gas chamber 4 and the standard state pressure value P0 to the PLC terminal control device 14;

[0061] Temperature sensor 11 transmits the measured ambient temperature data and the constant temperature control value T0 set in step 2 to signal transmission device 15, and signal transmission device 15 transmits the ambient temperature data and constant temperature control value T0 to PLC terminal control device 14.

[0062] Step 4, the PLC terminal control device 14 adjusts the pressure value P of the regulating air chamber 4 according to the obtained pressure value P. c After the standard pressure value P0, the PLC terminal control device 14 calculates the required regulating gas volume V, and controls the air pump 7 or air pump 8 in the regulating gas chamber 4 to work and regulate the pressure in the working gas chamber 3 to P0.

[0063] At the same time, the temperature in the working gas chamber 3 and the regulating gas chamber 4 is regulated by the constant temperature control device 12. When the temperature reaches the constant temperature state, that is, when the temperature data measured by the temperature sensor 11 reaches the constant temperature control value T0, the gas to be tested can be input into the infrared gas analyzer 5 through the gas inlet pipe 6 to measure the gas concentration.

[0064] Step 5: After the measurement is completed, the gas is vented through the gas outlet pipe 17.

[0065] In step 4, the calculation process of the PLC terminal control device 14 is as follows:

[0066] Step a, first determine the pressure difference to be compensated according to formula (1):

[0067] ΔP=P c -P0 (1)

[0068] Where: ΔP is the pressure difference to be compensated, kPa; P0 is the standard state pressure value of the second pressure sensor 13, set in kPa; P c The pressure value of the regulating chamber 4 measured by the first pressure sensor 16, in kPa;

[0069] Step b, calculate the required volume of regulating gas V according to formula (8):

[0070]

[0071] Where: V is the required volume of the regulating gas, m 3 C represents the adjusting gas molar concentration, in mol / L; V t To adjust the standard gas volume, L / mol, R is the ideal gas constant, T is the Kelvin temperature, K, T = 273.15 + T0, T0 is the set constant temperature control value of temperature sensor 11, °C;

[0072] Specifically, formula (8) is calculated through the following steps:

[0073] From the ideal gas equations (2) and (3),

[0074] P c V = nRT (2)

[0075] T = 273.15 + T0 (3)

[0076] Where: P c V is the pressure value of the regulating gas chamber measured by the first pressure sensor 16, in kPa; V is the required regulating gas volume, in m³. 3 n is the number of moles of the regulating gas, in mol; R is the ideal gas constant, R = 8.13; T0 = 45℃, T = 318.15K;

[0077] have to:

[0078]

[0079]

[0080] because:

[0081]

[0082] n = CV t (7)

[0083] In equations (6) and (7): C is the molar concentration of the regulating gas, mol / L; V t To adjust the standard volume of the gas, m 3 ;

[0084] but:

[0085]

[0086] In this embodiment, C = 0.045 mol / L, V t =1m 3 R = 8.13, T = 318.15K. Substituting these values ​​into equation (8), we get...

[0087] In step 1 of this embodiment, the first pressure sensor 16 in the regulating chamber 4 measures the pressure value P of the regulating chamber 4. c The pressures are 80 kPa, 85 kPa, 90 kPa, 95 kPa, 105 kPa, 110 kPa, 115 kPa, and 120 kPa, respectively. Based on the measured pressure value P of the regulating chamber 4... c ΔP is calculated using formula (1), and the required volume of regulating gas V is calculated using formula (8). The calculation results are shown in Table 1.

[0088] Table 1. Required volume of regulating gas V for working chamber pressure regulation

[0089]

[0090] Step c: The PLC terminal control device controls the air pump 7 or the air pump 8 to fill or evacuate the working gas chamber according to the required adjustment gas volume V calculated in step b, and adjust the working gas chamber pressure to P0 (P0 = 100 kPa).

[0091] Table 2 shows the gas concentration values ​​measured by the infrared gas analyzer 5 under constant temperature conditions (T0 = 45℃) with different pressure values ​​Pc of the regulating gas chamber 4.

[0092] Table 2. Actual CH4 concentration measured by the infrared gas analyzer after pressure compensation.

[0093]

[0094] Comparative Example

[0095] The infrared gas analyzer 5 was kept at a constant temperature of 45℃, and the pressure value P of the gas chamber 4 was adjusted. c Similar to Example 2, without pressure compensation, the actual CH4 concentration measured by the infrared gas analyzer 5 is shown in Table 3.

[0096] Table 3. Actual CH4 concentration measured by an infrared gas analyzer without pressure compensation.

[0097]

[0098] As can be seen from Embodiment 2 and the comparative example of the present invention, the actual measured gas concentration value of the infrared gas analyzer 5 after pressure compensation in Embodiment 2 converges towards the standard gas concentration value, thereby improving the measurement accuracy of the infrared gas analyzer.

[0099] This invention constructs a pressure compensation device and method for measuring gas concentration values ​​using an infrared gas analyzer 5 under different pressure environments at constant temperature. Simultaneously, the ambient pressure during the calibration of the infrared gas analyzer 5, i.e., the standard state pressure value P0 = 100 kPa set by the second pressure sensor 13, the constant temperature condition T0 = 45℃, and the gas concentrations to be measured at 2%, 4%, 6%, 8%, and 10% of the full scale of the infrared gas analyzer 5, are selected as reference benchmarks for pressure compensation. Pressure compensation is performed on gases under different ambient pressure conditions, correcting the deviation in the measured gas concentration values ​​of the infrared gas analyzer 5 caused by changes in ambient pressure. This allows the testing accuracy of the infrared gas analyzer 5 to converge towards the standard gas concentration value, thereby achieving the effect of pressure compensation. The embodiments of this invention provide a pressure compensation device and method for measuring CH4 using an infrared gas analyzer 5. In practical applications, the same compensation can be performed on infrared gas analyzers measuring other gases, which will not be elaborated further here.

[0100] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An environmental pressure compensation device for an infrared gas analyzer under constant temperature conditions, characterized in that, The device includes a sealed enclosure, inside which is a hollow cylindrical working gas chamber shell. The upper surface of the working gas chamber shell is attached to the top surface of the sealed enclosure, and the lower surface of the working gas chamber shell is attached to the lower surface of the sealed enclosure. The working gas chamber shell divides the interior of the sealed enclosure into a working gas chamber and a regulating gas chamber. An infrared gas analyzer is placed inside the working gas chamber. A first pressure sensor and a pressure regulating device are provided in the regulating air chamber. The first pressure sensor is used to measure the pressure in the regulating air chamber, and the pressure regulating device is used to regulate the pressure inside the working air chamber. The regulating air chamber is also equipped with a temperature sensor, which is used to measure the ambient temperature of the regulating air chamber. A constant temperature control device and a second pressure sensor are installed on the working air chamber shell. The constant temperature control device is used to regulate the temperature in the regulating air chamber and the working air chamber, and the second pressure sensor is used to measure the pressure in the working air chamber. The voltage regulating device and the constant temperature control device are both connected to the PLC terminal control device via wires; A signal transmission device is installed at the bottom of the sealed housing. The signal transmission device is connected to the first pressure sensor, the second pressure sensor, and the temperature sensor via wires. The signal transmission device is also connected to the PLC terminal control device. The signal transmission device receives the pressure data measured by the first pressure sensor and the second pressure sensor, as well as the temperature data measured by the temperature sensor, and transmits it to the PLC terminal control device. The PLC terminal control device controls the pressure regulating device to adjust the gas pressure in the working chamber to reach the standard pressure state, and controls the temperature control device to adjust the working chamber and the temperature in the regulating chamber to reach a constant temperature state. The pressure regulating device includes an air pump, an air pump, an air pump drive motor, and an air pump drive motor. The air pump drive motor and the air pump drive motor are respectively connected to a PLC terminal control device. The air pump drive motor is connected to an air pump, and the air pump drive motor is connected to an air pump. The air pump and the air pump are respectively connected to the working air chamber for filling and evacuating air into the working air chamber, thereby realizing the pressure regulation of the working air chamber. The standard pressure state is when the pressure in the working chamber reaches the standard pressure value P0 set by the second pressure sensor, and the constant temperature state is when the temperature data measured by the temperature sensor reaches the constant temperature control value T0 set by the temperature sensor. The standard pressure value P0 = 100 kPa and the constant temperature control value T0 = 45℃.

2. The environmental pressure compensation device for an infrared gas analyzer under constant temperature conditions as described in claim 1, characterized in that, The sealed box is a hollow cylindrical structure.

3. The environmental pressure compensation device for an infrared gas analyzer under constant temperature conditions as described in claim 1, characterized in that, The regulating chamber is located at room temperature and normal pressure, and the regulating gas inside the regulating chamber is air.

4. The environmental pressure compensation device for an infrared gas analyzer under constant temperature conditions as described in claim 1, characterized in that, The constant temperature control device includes a heating device and a cooling device, which are respectively connected to a PLC terminal control device.

5. The environmental pressure compensation device for an infrared gas analyzer under constant temperature conditions as described in claim 1, characterized in that, The working gas chamber is also equipped with a gas inlet pipe and a gas outlet pipe. The gas inlet pipe and the gas outlet pipe are embedded in the infrared gas analyzer. The gas inlet pipe is equipped with an inlet valve, and the gas outlet pipe is equipped with an outlet valve. The inlet valve and the outlet valve are respectively connected to the PLC terminal control device.

6. A method for compensating the environmental pressure of an infrared gas analyzer under constant temperature conditions, implemented using the environmental pressure compensation device for an infrared gas analyzer under constant temperature conditions as described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Measure the pressure value P in the regulating chamber using the first pressure sensor within the regulating chamber. c ; Step 2: When starting the measurement work, first set the standard state pressure value of the second pressure sensor in the working chamber to P0 and the constant temperature control value of the temperature sensor to T0. Step 3, the first pressure sensor will measure the pressure value P in the regulating air chamber. c The second pressure sensor transmits the standard pressure value P0 to the signal transmission device, which then transmits the acquired pressure value P of the regulating chamber. c The standard pressure value P0 is transmitted to the PLC terminal control device. The temperature sensor transmits the measured ambient temperature data and the constant temperature control value T0 set in step 2 to the signal transmission device, and the signal transmission device transmits the ambient temperature data and the constant temperature control value T0 to the PLC terminal control device. Step 4, the PLC terminal control device determines the pressure value P of the regulating air chamber based on the obtained pressure value P. c After the standard pressure value P0 is obtained, the required regulating gas volume V is calculated by the PLC terminal control device. The PLC terminal control device controls the air pump or air pump in the regulating gas chamber to regulate the pressure in the working gas chamber to P0. Meanwhile, the temperature in the working gas chamber and the regulating gas chamber is adjusted by the constant temperature control device. When the temperature reaches the constant temperature state, that is, when the temperature data measured by the temperature sensor reaches the constant temperature control value T0, the gas to be tested can be input into the infrared gas analyzer through the gas inlet pipe for gas concentration measurement. Step 5: After the measurement is completed, the gas is vented through the gas outlet tube.

7. The method for compensating for environmental pressure in an infrared gas analyzer under constant temperature conditions as described in claim 6, characterized in that, In step 4, the calculation process of the PLC terminal control device is as follows: Step a, first determine the required pressure difference to be compensated according to formula (1): ΔP=P c -P0 (1); Where: ΔP is the pressure difference to be compensated, kPa; P0 is the standard state pressure value of the second pressure sensor; P c The pressure value of the regulating chamber measured by the first pressure sensor, in kPa; Step b, calculate the required volume of regulating gas V according to formula (8): ； Where: V is the required volume of the regulating gas, m 3 C represents the adjusting gas molar concentration, in mol / L; V t To adjust the standard gas volume, L / mol, R is the ideal gas constant, T is the Kelvin temperature, K, T = 273.15 + T0, T0 is the set temperature sensor constant temperature control value, °C; Step c: The PLC terminal control device controls the air pump or air pump to fill or evacuate the working gas chamber according to the required adjustment gas volume V calculated in step b, and adjust the working gas chamber pressure to P0.

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