Constant temperature control and detection device of gas sensor

Abstract

The invention discloses a constant-temperature control and detection device of a gas sensor. The constant-temperature control and detection device comprises a filter assembly, a gas chamber, a semiconductor chilling plate, a heat dissipation assembly and a temperature controller, wherein the semiconductor chilling plate and the heat dissipation assembly are arranged on the gas chamber; the gas chamber comprises a sample gas pretreatment gas chamber, a constant-temperature detection gas chamber arranged beside the sample gas pretreatment gas chamber, and a liquid storage assembly arranged below the sample gas pretreatment gas chamber; the filtering assembly is communicated with the sample gas pretreatment gas chamber; and the sample gas pretreatment gas chamber is also respectively communicated with the liquid storage assembly and the constant-temperature detection gas chamber. According to the invention, the direction of the driving current of the semiconductor chilling plate is changed, so that heating and refrigerating functions are realized at the same time; the front-stage'sample gas pretreatment gas chamber 'realizes rapid heating / cooling of sampled gas, and also realizes filtration and collection of condensed water in the cooling process; and the rear-stage constant-temperature detection gas chamber realizes constant-temperature control on the detection gas chamber, so that the gas sensor, the temperature and humidity sensor and the gas chamber are in a constant room temperature range most suitable for detection.

Description

Technical Field

[0001] The present invention relates to the technical field of gas sensors, and in particular to a constant temperature control and detection device for a gas sensor. Background Art

[0002] As the country attaches great importance to public safety and the public's environmental awareness increases, the demand for monitoring the atmospheric environment and pollutants is growing, which has promoted the rapid development of the atmospheric monitoring industry. In this field, electrochemical gas sensors are able to detect a variety of atmospheric pollutants, such as carbon monoxide (CO), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ) and ozone (O 3 ) and become one of the key technologies. These sensors, with their low range and high precision, play an important role in accurately monitoring and analyzing atmospheric pollutants.

[0003] However, traditional electrochemical gas sensors have some significant limitations in practical applications. First, these sensors are very sensitive to the temperature and humidity of the environment and can usually only work properly within a narrow temperature range (0-40°C). In outdoor environments, due to large temperature fluctuations, these sensors often have difficulty maintaining stable detection accuracy. Under extreme climatic conditions, such as temperatures below -20°C or above 50°C, the sensors may suffer permanent damage, resulting in false alarms or missed alarms, seriously affecting the reliability of the monitoring results.

[0004] In order to meet these challenges, constant temperature control technology is currently widely used in the industry to maintain the operating temperature of the sensor. However, existing constant temperature control solutions have many shortcomings. Some solutions only provide heating functions and cannot effectively control the sensor temperature in a high temperature environment, resulting in a decrease in sensor performance. Although other solutions have cooling capabilities, the cooling effect is poor in ultra-high temperature environments (such as over 50°C), and the sensor temperature cannot be stabilized within the optimal working range (25±5°C), thus failing to ensure detection accuracy. In addition, some cooling solutions will cause an increase in relative humidity while lowering the temperature, and then form condensed water on the sensor surface, which not only affects the normal operation of the sensor, but may even cause damage to the sensor. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a constant temperature control and detection device for a gas sensor, wherein a sample gas pretreatment chamber mainly realizes constant temperature treatment of the ambient gas sample gas, so that the sample gas temperature enters the optimal detection temperature range. At the same time, if it is in a high temperature environment, the condensed water generated in the condensation process of the sample gas is collected to prevent the condensed water from entering the rear end constant temperature detection chamber; the constant temperature detection chamber mainly realizes constant temperature control of the detection sensor and the circuit, so that the sensor and the circuit are in the optimal operating temperature range; at the same time, because the front-stage sample gas pretreatment chamber has pre-cooled and dehumidified the sample gas, after the sample gas enters the constant temperature detection chamber, its temperature is close to that of the sensor, thereby avoiding the high-temperature sample gas from entering the low-temperature sensor, thereby causing water droplets to condense on the sensor surface.

[0006] In order to achieve the above-mentioned object, the present invention provides a constant temperature control and detection device for a gas sensor, comprising: a filter component, an air chamber, a semiconductor cooling sheet and a heat dissipation component placed on the air chamber, and a temperature controller;

[0007] The gas chamber comprises a sample gas pretreatment gas chamber, a constant temperature detection gas chamber arranged next to the sample gas pretreatment gas chamber, and a liquid storage assembly arranged below the sample gas pretreatment gas chamber;

[0008] The filter assembly is connected to the sample gas pretreatment chamber and is used to filter water vapor and dust in the sample gas;

[0009] The sample gas pretreatment chamber is also connected to the liquid storage component and the constant temperature detection chamber respectively, and is used to adjust the temperature of the filtered gas sample;

[0010] A gas detection component is also provided in the constant temperature detection air chamber, and the constant temperature detection air chamber is used to maintain the gas detection component to operate at an optimal working temperature;

[0011] The liquid storage component is used to collect condensed water generated in the sample gas pretreatment chamber during the cooling process;

[0012] The semiconductor refrigeration sheet is used to heat or cool the air chamber;

[0013] The heat dissipation component is also connected to the constant temperature detection air chamber for exchanging heat with the environment and assisting the semiconductor refrigeration sheet in regulating the temperature;

[0014] The corresponding end of the temperature controller is electrically connected to the semiconductor refrigeration chip, and is used to drive the semiconductor refrigeration chip to achieve heating or cooling of the sample gas pretreatment chamber and the constant temperature detection chamber.

[0015] Preferably, the constant temperature control and detection device of the gas sensor also includes an insulation component, a thermocouple, and a signal acquisition board; the gas chamber is placed in the insulation component; the thermocouple is placed in the gas chamber for temperature detection of the gas chamber; the corresponding end of the temperature controller is also electrically connected to the corresponding end of the thermocouple.

[0016] Preferably, the thermal insulation component includes thermal insulation foam and glass wool connected to the top of the thermal insulation foam, wherein the thermal insulation foam and glass wool are used for insulation to prevent the air chamber from directly exchanging heat with the external environment or the heat dissipation component; a notch is opened in the middle of the glass wool, and the semiconductor refrigeration plate is placed in the notch; the heat dissipation component is arranged on the glass wool.

[0017] Preferably, a serpentine air path is provided in the sample gas pretreatment chamber so that the sample gas has sufficient contact area with the chamber wall to quickly adjust the sample gas temperature to the temperature set by the temperature controller; one end of the serpentine air path is connected to the filter assembly, and the other end is connected to the constant temperature detection chamber.

[0018] Preferably, the filter assembly comprises a filter, which uses a polymer PTFE filter element to filter water vapor and dust in the gas sample.

[0019] Preferably, the liquid storage component includes a condensation reflux liquid storage tank and a condensation reflux pipe; the condensation reflux liquid storage tank is connected to the serpentine air path through the condensation reflux pipe; the bottom of the condensation reflux liquid storage tank is also connected to a condensation reflux drain pipe, and a solenoid valve is also installed on the condensation reflux drain pipe, and the corresponding end of the solenoid valve is electrically connected to the corresponding end of the signal acquisition board.

[0020] Preferably, the constant temperature detection air chamber is further provided with a sensor circuit board, an oxygen-reducing resin, a filter membrane, a sealing gasket, and a sealing ring;

[0021] The gas detection components are all arranged on a sensor circuit board, and sensor fixing housings are also installed on both sides of the sensor circuit board for fixing the gas detection components;

[0022] The corresponding end of the sensor circuit board is also electrically connected to the corresponding end of the signal acquisition board;

[0023] The reducing resin is arranged at the bottom of the sensor circuit board and is used for sealing the sensor circuit board and external leads;

[0024] The sealing gasket is used to seal the sensor fixed housing and the gas detection component; the filter membrane is arranged on the sealing gasket;

[0025] The sealing ring is arranged on the filter membrane and abuts against the wall of the constant temperature detection air chamber, and is used for sealing between the gas detection component and the wall of the constant temperature detection air chamber.

[0026] Preferably, the gas detection component comprises a gas sensor and a temperature and humidity sensor, and the gas sensor and the temperature and humidity sensor are used to detect the gas concentration and the temperature and humidity in the gas chamber.

[0027] Preferably, the heat dissipation assembly includes a radiator, which includes a heat dissipation base, a radiator air duct arranged on the heat dissipation base, and a heat sink arranged on the heat dissipation base and placed above the radiator air duct; a plug is also installed on the radiator air duct; the air inlet of the radiator air duct is connected to the constant temperature detection air chamber through an air connecting pipe.

[0028] Preferably, the sealing ring and the sealing gasket are made of nitrile rubber, the filter membrane is made of high molecular PTFE membrane; and the heat insulating foam is made of polyurethane foam plastic.

[0029] The technical solution of the present invention has the following beneficial effects:

[0030] The present invention realizes heating and cooling functions at the same time by changing the direction of the driving current of the semiconductor refrigeration plate; the front-stage "sample gas pretreatment chamber" realizes rapid heating / cooling of the sampled gas, and realizes filtering and collection of condensed water during the cooling process; the rear-stage "constant temperature detection chamber" realizes constant temperature control of the detection chamber, so that the gas sensor, the temperature and humidity sensor and the chamber are in a constant room temperature range most suitable for detection; in a high temperature and high humidity environment, the sample gas is first cooled and dehumidified to ensure that the internal humidity of the "constant temperature detection chamber" is within a reasonable range, and the sample gas temperature is consistent with the sensor temperature, and condensed water droplets cannot be generated on the sensor surface. At the same time, the sampling tail gas secondary utilization technology reduces energy loss and improves cooling or heating efficiency; therefore, the detection accuracy and service life in harsh environments are greatly improved, thereby solving the above-mentioned problems.

[0031] The present invention adopts a two-stage graded air chamber design to adjust the temperature of the sampled gas and the sensor respectively, so that the temperature is more stable and the surface and internal temperatures of the sensor are more balanced; the front "sample gas pretreatment air chamber" design can quickly realize the temperature increase / lowering treatment of the sampled gas, and filter and collect the condensed water when cooling; the exhaust gas reuse design allows the gas in the constant temperature air chamber to return to the radiator after detection, and utilizes the huge temperature difference between the sample gas and the radiator to quickly exchange heat with the radiator, thereby improving the temperature control efficiency.

[0032] The present invention ensures that the gas sensor always operates at the optimal operating temperature, thereby significantly improving the detection accuracy of atmospheric pollutants. The present invention can work normally under extreme temperature conditions (such as below -20 degrees Celsius or above 50 degrees Celsius), expanding the application range of gas sensors and making them suitable for more environments; the constant temperature detection chamber has a built-in temperature and humidity sensor, allowing the signal acquisition board to monitor the state of the chamber at any time, and compensate and correct the detection data according to the actual temperature and humidity conditions. At the same time, if the temperature and humidity are detected to be out of range, a fault alarm can be issued.

[0033] The present invention avoids humidity increase and condensation water generation caused by refrigeration through effective temperature and humidity control, ensures that the sensor surface always remains dry, and thus improves the stability and accuracy of the sensor; the temperature controller and signal acquisition board integrated in the present invention realize automatic temperature regulation and fault alarm, reduces manual intervention, and improves the intelligence level of the system.

[0034] The heat dissipation component and thermal insulation component designs of the present invention optimize the heat exchange efficiency and improve the speed and effect of constant temperature control; the use of high-efficiency materials such as polyurethane foam plastics and polymer PTFE membranes improves the durability and performance of the device; the present invention uses thermal insulation foam plastics to wrap the air chamber, which greatly reduces the heat exchange rate between the air chamber and the external environment, thereby effectively reducing the temperature control power and temperature stability; the use of thermal insulation glass wool boards to isolate the air chamber and the radiator, greatly reducing the heat exchange rate between the air chamber and the radiator, thereby effectively improving the temperature control efficiency and temperature balance; by reducing energy consumption, reducing maintenance requirements and extending sensor life, the present invention provides a cost-effective atmospheric pollutant monitoring solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the structural layout of the present invention;

[0036] Figure 2 It is a schematic diagram of the structure of the present invention;

[0037] Figure 3 For the present invention Figure 2 Sectional view of AA;

[0038] Figure 4 For the present invention Figure 3 Cross-section view of BB

[0039] Figure 5 It is an exploded view of the structure of the present invention. DETAILED DESCRIPTION

[0040] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0041] Reference Figures 1 to 5The present invention provides a constant temperature control and detection device for a gas sensor, comprising: a filter component, an air chamber 89, a semiconductor cooling sheet 12 and a heat dissipation component placed on the air chamber 89, and a temperature controller 15;

[0042] The gas chamber 89 includes a sample gas pretreatment gas chamber 8, a constant temperature detection gas chamber 9 placed next to the sample gas pretreatment gas chamber 8, and a liquid storage assembly placed below the sample gas pretreatment gas chamber 8;

[0043] The filter assembly is connected to the sample gas pretreatment chamber 8, and is used to filter the water vapor and dust in the gas sample; the sample gas pretreatment chamber 8 is connected to the filter assembly, and the gas sample is first filtered to remove dust and other particles. Then, the gas sample is temperature-regulated in the pretreatment chamber 8 to ensure that its temperature meets the requirements of subsequent testing. In addition, the pretreatment chamber 8 is also responsible for collecting condensed water that may be generated when the temperature of the gas sample decreases to prevent it from affecting the test results.

[0044] The sample gas pretreatment chamber 8 is also connected to the liquid storage component and the constant temperature detection chamber 9 respectively, and is used to adjust the temperature of the filtered gas sample; it is used to pretreat the filtered gas sample so that the temperature of the sample gas rises or drops quickly to the chamber temperature; wherein the sample gas pretreatment chamber 8 is made of aluminum alloy, and is mainly used for temperature control of the sample gas, and realizes the collection of condensed water in a high temperature environment;

[0045] The constant temperature detection chamber 9 is also provided with a gas detection component, and the constant temperature detection chamber 9 is used to maintain the gas detection component to operate at an optimal working temperature; wherein the constant temperature detection chamber is made of aluminum alloy;

[0046] The liquid storage component is used to collect condensed water generated in the sample gas pretreatment chamber during the cooling process; the design of the liquid storage component can prevent the condensed water from flowing back into the pretreatment chamber or the detection chamber, thereby avoiding interference with the detection of the gas sample.

[0047] The semiconductor refrigeration sheet 12 is used to heat or cool the gas chamber to achieve constant temperature control and ensure that the gas detection component works at a suitable temperature;

[0048] The heat dissipation component is also connected to the constant temperature detection air chamber 9, and is used to exchange heat with the environment, assist the semiconductor refrigeration sheet 12 in regulating the temperature, and improve the heat exchange efficiency;

[0049] The corresponding end of the temperature controller 15 is electrically connected to the semiconductor refrigeration chip 12, and has a forward and reverse driving function, which is used to drive the semiconductor refrigeration chip 12 to achieve heating or cooling of the sample gas pretreatment chamber and the constant temperature detection chamber 9, and realize constant temperature control;

[0050] Furthermore, the constant temperature control and detection device of the gas sensor also includes an insulation component, a thermocouple 20, and a signal acquisition board 16; the gas chamber 89 is placed in the insulation component; the thermocouple 20 is placed in the gas chamber 89, and is used for temperature detection of the gas chamber 89; the corresponding end of the temperature controller 15 is also electrically connected to the corresponding end of the thermocouple 20; wherein the thermocouple 20 is used for temperature detection of the gas chamber 89, and the temperature controller 15 performs temperature control; the signal acquisition board 16: is used to collect signals of the gas sensor 6 and the temperature and humidity sensor 7 in the constant temperature detection gas chamber 9, as well as control the solenoid valve 18, to achieve automatic control.

[0051] Furthermore, the thermal insulation component includes thermal insulation foam 10 and glass wool 11 connected to the top of the thermal insulation foam 10, wherein the thermal insulation foam 10 and the glass wool 11 are used for insulation to prevent the air chamber 89 from directly exchanging heat with the external environment or the heat dissipation component; a notch is opened in the middle of the glass wool 11, and the semiconductor refrigeration plate 12 is placed in the notch; the heat dissipation component is arranged on the glass wool 11; the thermal insulation foam 10 adopts polyurethane foam plastic (PU), which is mainly used for insulation of the air chamber 89 to prevent the air chamber 89 from exchanging heat with the external environment; glass wool 11: mainly used for insulation between the air chamber 11 and the heat dissipation component to prevent the air chamber from directly exchanging heat with the radiator.

[0052] Furthermore, a serpentine gas path channel 30 is provided in the sample gas pretreatment chamber 8, so that the sample gas has sufficient contact area with the chamber wall to quickly adjust the sample gas temperature to the temperature set by the temperature controller 15; one end of the serpentine gas path channel 30 is connected to the filter component, and the other end is connected to the constant temperature detection chamber 9; the main function of the sample gas pretreatment chamber 8 is to adjust the temperature of the filtered gas sample so that it reaches a temperature condition suitable for gas detection. It achieves rapid and accurate temperature control by working in coordination with the semiconductor refrigeration plate 12 and the temperature controller 15; the serpentine gas path channel 30 is an important structure in the sample gas pretreatment chamber 8, and its design purpose is to increase the contact area between the sample gas and the chamber wall. This design enables the sample gas to more effectively exchange heat with the chamber wall when passing through the chamber, thereby accelerating the sample gas temperature adjustment speed and quickly reaching the target temperature set by the temperature controller; the serpentine gas path channel 30 increases the residence time of the sample gas in the chamber through its extended path, which helps to improve the heat exchange efficiency and ensure the uniformity and accuracy of the sample gas temperature.

[0053] Furthermore, the filter assembly includes a filter 13, which uses a high molecular PTFE (polytetrafluoroethylene) filter element to filter water vapor and dust in the gas sample; the filter assembly is connected to one end of the serpentine gas channel 30 to ensure that the filtered gas sample can smoothly enter the sample gas pretreatment chamber 8.

[0054] Furthermore, the liquid storage assembly includes a condensation reflux liquid storage tank 17 and a condensation reflux pipe 171; the condensation reflux liquid storage tank 17 is connected to the serpentine gas path 30 through the condensation reflux pipe 171; the bottom of the condensation reflux liquid storage tank 17 is also connected to a condensation reflux drain pipe 171, and a solenoid valve 18 is also installed on the condensation reflux drain pipe 171, and the corresponding end of the solenoid valve 18 is electrically connected to the corresponding end of the signal acquisition board 16;

[0055] The main function of the liquid storage component is to collect the condensed water generated in the sample gas pretreatment chamber 8 during the cooling process. By effectively collecting and storing the condensed water, the liquid storage component prevents the condensed water from flowing back into the sample gas pretreatment chamber 8 or entering the constant temperature detection chamber 9, thereby avoiding affecting the accuracy of gas detection; the condensation reflux liquid storage tank 17 is a part of the liquid storage component, which is used to store the condensed water generated from the serpentine gas path channel 30. It is designed to accommodate the condensed water and can be discharged through the drain pipe at the bottom.

[0056] Furthermore, the constant temperature detection air chamber 9 is also provided with a sensor circuit board 5, an epoxy resin 19, a filter membrane 1, a sealing gasket 3, and a sealing ring 2; the gas detection components are all arranged on the sensor circuit board 5, and sensor fixing shells 4 are also installed on both sides of the sensor circuit board 5 for fixing the gas detection components; the sealing ring 3 and the sealing gasket 2 are made of nitrile rubber, and the filter membrane 1 is made of a polymer PTFE (polytetrafluoroethylene) membrane, which is used for filtering water vapor on the sensor surface; the thermal insulation foam 10 is made of polyurethane foam plastic.

[0057] The corresponding end of the sensor circuit board 5 is also electrically connected to the corresponding end of the signal acquisition board 15;

[0058] The reducing resin 19 is disposed at the bottom of the sensor circuit board 5 and is used to seal the sensor circuit board 5 and external leads to prevent gas leakage in the detection chamber;

[0059] The sealing pad 3 is used to seal the sensor fixed housing 4 and the gas detection component, reduce the cavity dead angle in the sensor fixed housing 4, prevent gas residue, and improve the response speed. The sealing pad 3 is made of nitrile rubber; the filter membrane 1 is arranged on the sealing pad 3;

[0060] The sealing ring 2 is arranged on the filter membrane 1 and abuts against the wall of the constant temperature detection chamber 9. It is used for sealing between the gas detection component and the constant temperature detection chamber wall 9, reducing the cavity dead corners in the constant temperature detection chamber 9, preventing gas residue, and improving the response speed; wherein the filter membrane 1: adopts a polymer PTFE (polytetrafluoroethylene) membrane, the sealing ring 2 is made of nitrile rubber, and the sensor fixed shell 4 is made of aluminum alloy.

[0061] Furthermore, the gas detection component includes a gas sensor 6 and a temperature and humidity sensor 7, which are used to detect the gas concentration and temperature and humidity in the gas chamber; the gas sensor 6 is specially designed to detect the concentration of a specific gas in the gas chamber. This sensor can respond to specific gas molecules and convert them into electrical signals, so that subsequent analysis and processing can be performed. The gas sensor 6 is widely used in environmental monitoring, industrial safety, medical diagnosis and other fields, and can detect including but not limited to carbon monoxide (CO), carbon dioxide (CO 2 ), oxygen (O 2 ), hydrogen sulfide (H 2 S) and other gases. The temperature and humidity sensor 7 is responsible for measuring the temperature and humidity in the air chamber. Temperature and humidity are important factors affecting the accuracy of gas detection. Therefore, the temperature and humidity sensor provides real-time data to ensure that gas detection is carried out under optimal conditions. By real-time monitoring of the gas concentration and temperature and humidity in the air chamber, the temperature and humidity sensor 7 provides the system with necessary feedback, so that the temperature controller 15 can adjust the working state of the semiconductor refrigeration sheet 12 to maintain a suitable environment in the constant temperature detection air chamber 9.

[0062] Furthermore, the heat dissipation assembly includes a radiator, which includes a heat dissipation base 141, a radiator air channel 140 arranged on the heat dissipation base 141, and a heat sink 142 arranged on the heat dissipation base 141 and placed above the radiator air channel 140; a plug 143 is also installed on the radiator air channel 140; the air inlet of the radiator air channel 140 is connected to the constant temperature detection air chamber 9 through an air connection pipe 33; wherein the radiator 14 is made of aluminum alloy and can be equipped with a fan, which is mainly used for rapid heat exchange with ambient air. The heat sink 141 provides a stable installation foundation for the radiator 14 and serves as a supporting structure for the radiator airway 140 and the heat sink 142. The radiator airway 140 is a channel for gas circulation, which is used to guide the heat in the constant temperature detection air chamber to the heat sink 142 and dissipate it to the external environment through the heat sink 142. The plug 143 is installed at one end of the radiator airway 140 to close the radiator airway 140 to prevent dust and other impurities from entering the interior of the radiator 14, and at the same time, it can also enhance the structural integrity of the airway.

[0063] The working principle of the present invention is as follows:

[0064] Atmospheric air passes through the filter 13 to filter out dust in the air, and then the sample gas enters the sample gas pretreatment chamber 8. The serpentine air path 30 inside the sample gas pretreatment chamber ensures that the sample gas has sufficient contact area with the chamber 89, so that the temperature of the sample gas can quickly rise / fall to near the chamber temperature (i.e., the set temperature of the temperature controller 15); in a low-temperature environment, the inlet sample gas temperature is lower than the chamber temperature. After the sample gas enters, it exchanges heat with the chamber, and the heat is transferred from the chamber to the sample gas. The sample gas temperature rises, the absolute humidity in the sample gas remains unchanged, but the relative humidity decreases, and no water droplets are generated; in a high-temperature environment, the inlet sample gas temperature is higher than the chamber temperature. After the sample gas enters, it exchanges heat with the chamber, and the heat is transferred from the sample gas to the chamber. The sample gas temperature decreases, and at the same time, the sample gas contacts the cold chamber wall to produce condensed water, which is collected along the chamber wall under the action of gravity into the condensation reflux liquid storage tank 17.

[0065] The sample gas after pretreatment enters the inner cavity of the constant temperature detection chamber 9, and then diffuses freely to the surface of the gas sensor 6 and the temperature and humidity sensor 7. During the diffusion process, the sample gas temperature is first filtered again through the filter membrane 1. At this time, the sample gas temperature is basically consistent with the chamber temperature (i.e., the set temperature of the temperature controller 15), and both are within the optimal detection temperature range of the gas sensor 6 and the temperature and humidity sensor 7. During this period, the temperature and humidity are roughly in a relatively constant state, which is conducive to improving the detection accuracy and stability of the gas sensor 6 and the temperature and humidity sensor 7. In addition, the temperature and humidity sensor 7 pre-placed in the constant temperature detection chamber 9 can detect the temperature and humidity inside the constant temperature detection chamber 9 in real time to determine whether the temperature controller 15 is faulty and send out an alarm signal.

[0066] After the sample gas is discharged from the constant temperature detection air chamber 9, it enters the air pipe inside the radiator 14 again, and is finally discharged from the other end of the radiator 14; since the temperature of the sample gas is very different from the temperature of the radiator 14, the sample gas is reused again, thereby improving the energy utilization efficiency; in a low temperature environment, the sample gas temperature is higher than the ambient temperature, and the radiator 14 temperature is lower than the ambient temperature. Heat enters the radiator 14 through heat exchange, and then re-enters the air chamber 89 from the semiconductor refrigeration plate 12, reducing heat loss, which is faster and more effective than the radiator 14 absorbing heat from the ambient air; in a high temperature environment, the sample gas temperature is lower than the ambient temperature, and the radiator 14 temperature is higher than the ambient temperature. Heat enters the sample gas through heat exchange, and the sample gas absorbs a large amount of heat, which is faster and more effective than the radiator 14 dissipating heat into the environment.

[0067] The temperature controller 15 obtains the temperature conditions in the air chamber 89 in real time through the thermocouple 20, and controls the semiconductor refrigeration chip 12 according to the set temperature. If the set temperature is lower than the actual temperature of the air chamber, the semiconductor refrigeration chip 12 is driven forward, and heat is transferred from the air chamber 89 to the radiator 14 to achieve the cooling function; if the set temperature is higher than the actual temperature of the air chamber, the semiconductor refrigeration chip 12 is driven reversely, and heat is transferred from the radiator 14 to the air chamber to achieve the heating function.

[0068] It can be seen from the above embodiments that the present invention realizes the heating and cooling functions at the same time by changing the direction of the driving current of the semiconductor refrigeration plate; the front-stage "sample gas pretreatment chamber" realizes rapid heating / cooling of the sampled gas, and at the same time realizes the filtering and collection of condensed water during the cooling process; the rear-stage "constant temperature detection chamber" realizes constant temperature control of the detection chamber, so that the gas sensor and the temperature and humidity sensor and the chamber are in a constant room temperature range that is most suitable for detection; in a high temperature and high humidity environment, the sample gas is first cooled and dehumidified to ensure that the internal humidity of the "constant temperature detection chamber" is within a reasonable range, and at the same time the sample gas temperature is consistent with the sensor temperature, and condensed water droplets cannot be generated on the sensor surface. At the same time, the sampling exhaust gas secondary utilization technology reduces energy loss and improves cooling or heating efficiency; therefore, the detection accuracy and service life in harsh environments are greatly improved, thereby solving the above-mentioned problems.

[0069] The present invention adopts a two-stage graded air chamber design to adjust the temperature of the sampled gas and the sensor respectively, so that the temperature is more stable and the surface and internal temperatures of the sensor are more balanced; the front "sample gas pretreatment air chamber" design can quickly realize the temperature increase / lowering treatment of the sampled gas, and filter and collect the condensed water when cooling; the exhaust gas reuse design allows the gas in the constant temperature air chamber to return to the radiator after detection, and utilizes the huge temperature difference between the sample gas and the radiator to quickly exchange heat with the radiator, thereby improving the temperature control efficiency.

[0070] The present invention ensures that the gas sensor always operates at the optimal operating temperature, thereby significantly improving the detection accuracy of atmospheric pollutants. The present invention can work normally under extreme temperature conditions (such as below -20 degrees Celsius or above 50 degrees Celsius), expanding the application range of gas sensors and making them suitable for more environments; the constant temperature detection chamber has a built-in temperature and humidity sensor, allowing the signal acquisition board to monitor the state of the chamber at any time, and compensate and correct the detection data according to the actual temperature and humidity conditions. At the same time, if the temperature and humidity are detected to be out of range, a fault alarm can be issued.

[0071] The present invention avoids humidity increase and condensation water generation caused by refrigeration through effective temperature and humidity control, ensures that the sensor surface always remains dry, and thus improves the stability and accuracy of the sensor; the temperature controller and signal acquisition board integrated in the present invention realize automatic temperature regulation and fault alarm, reduces manual intervention, and improves the intelligence level of the system.

[0072] The heat dissipation component and thermal insulation component designs of the present invention optimize the heat exchange efficiency and improve the speed and effect of constant temperature control; the use of high-efficiency materials such as polyurethane foam plastics and polymer PTFE membranes improves the durability and performance of the device; the present invention uses thermal insulation foam plastics to wrap the air chamber, which greatly reduces the heat exchange rate between the air chamber and the external environment, thereby effectively reducing the temperature control power and temperature stability; the use of thermal insulation glass wool boards to isolate the air chamber and the radiator, greatly reducing the heat exchange rate between the air chamber and the radiator, thereby effectively improving the temperature control efficiency and temperature balance; by reducing energy consumption, reducing maintenance requirements and extending sensor life, the present invention provides a cost-effective atmospheric pollutant monitoring solution.

[0073] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A constant temperature control and detection device for a gas sensor, characterized in that: include: Filter assembly, air chamber, semiconductor cooling sheet and heat dissipation assembly placed on the air chamber, and temperature controller; The gas chamber comprises a sample gas pretreatment gas chamber, a constant temperature detection gas chamber arranged next to the sample gas pretreatment gas chamber, and a liquid storage assembly arranged below the sample gas pretreatment gas chamber; The filter assembly is connected to the sample gas pretreatment chamber and is used to filter water vapor and dust in the sample gas; The sample gas pretreatment chamber is also connected to the liquid storage component and the constant temperature detection chamber respectively, and is used to adjust the temperature of the filtered gas sample; A gas detection component is also provided in the constant temperature detection air chamber, and the constant temperature detection air chamber is used to maintain the gas detection component to operate at an optimal working temperature; The liquid storage component is used to collect condensed water generated in the sample gas pretreatment chamber during the cooling process; The semiconductor refrigeration sheet is used to heat or cool the air chamber; The heat dissipation component is also connected to the constant temperature detection air chamber for exchanging heat with the environment and assisting the semiconductor refrigeration sheet in regulating the temperature; The corresponding end of the temperature controller is electrically connected to the semiconductor refrigeration chip, and is used to drive the semiconductor refrigeration chip to achieve heating or cooling of the sample gas pretreatment chamber and the constant temperature detection chamber.

2. The constant temperature control and detection device of the gas sensor according to claim 1, characterized in that: The constant temperature control and detection device of the gas sensor also includes a heat insulation component, a thermocouple, and a signal acquisition board; the gas chamber is placed in the heat insulation component; the thermocouple is placed in the gas chamber for temperature detection of the gas chamber; the corresponding end of the temperature controller is also electrically connected to the corresponding end of the thermocouple.

3. The constant temperature control and detection device of the gas sensor according to claim 2, characterized in that: The thermal insulation component includes thermal insulation foam and glass wool connected to the top of the thermal insulation foam, wherein the thermal insulation foam and glass wool are used for insulation to prevent the air chamber from directly exchanging heat with the external environment or the heat dissipation component; a notch is opened in the middle of the glass wool, and the semiconductor refrigeration plate is placed in the notch; the heat dissipation component is arranged on the glass wool.

4. The constant temperature control and detection device of the gas sensor according to claim 3, characterized in that: A serpentine gas path is provided in the sample gas pretreatment chamber, so that the sample gas has sufficient contact area with the chamber wall to quickly adjust the sample gas temperature to the temperature set by the temperature controller; one end of the serpentine gas path is connected to the filter component, and the other end is connected to the constant temperature detection chamber.

5. The constant temperature control and detection device for a gas sensor according to claim 4, characterized in that: The filter assembly comprises a filter, which adopts a high-molecular PTFE filter element and is used to filter water vapor and dust in the gas sample.

6. The constant temperature control and detection device for a gas sensor according to claim 5, characterized in that: The liquid storage component includes a condensation reflux liquid storage tank and a condensation reflux pipe; the condensation reflux liquid storage tank is connected to the serpentine air path through the condensation reflux pipe; the bottom of the condensation reflux liquid storage tank is also connected to a condensation reflux drain pipe, and a solenoid valve is also installed on the condensation reflux drain pipe, and the corresponding end of the solenoid valve is electrically connected to the corresponding end of the signal acquisition board.

7. The constant temperature control and detection device for a gas sensor according to claim 6, characterized in that: The constant temperature detection air chamber is also provided with a sensor circuit board, an oxygen-reducing resin, a filter membrane, a sealing pad, and a sealing ring; The gas detection components are all arranged on a sensor circuit board, and sensor fixing housings are also installed on both sides of the sensor circuit board for fixing the gas detection components; The corresponding end of the sensor circuit board is also electrically connected to the corresponding end of the signal acquisition board; The reducing resin is arranged at the bottom of the sensor circuit board and is used for sealing the sensor circuit board and external leads; The sealing gasket is used to seal the sensor fixed housing and the gas detection component; the filter membrane is arranged on the sealing gasket; The sealing ring is arranged on the filter membrane and abuts against the wall of the constant temperature detection air chamber, and is used for sealing between the gas detection component and the wall of the constant temperature detection air chamber.

8. The constant temperature control and detection device for a gas sensor according to claim 7, characterized in that: The gas detection component comprises a gas sensor and a temperature and humidity sensor, and the gas sensor and the temperature and humidity sensor are used to detect the gas concentration and the temperature and humidity in the gas chamber.

9. The constant temperature control and detection device of a gas sensor according to claim 4, characterized in that: The heat dissipation assembly includes a radiator, which includes a heat dissipation base, a radiator air duct arranged on the heat dissipation base, and a heat sink arranged on the heat dissipation base and placed above the radiator air duct; a plug is also installed on the radiator air duct; the air inlet of the radiator air duct is connected to the constant temperature detection air chamber through an air connecting pipe.

10. The constant temperature control and detection device of a gas sensor according to claim 7, characterized in that: The sealing ring and the sealing pad are made of nitrile rubber, the filtering membrane is made of high molecular PTFE membrane; and the heat insulating foam is made of polyurethane foam plastic.

Images