High-dew-point gas detection sensor
By installing a heat-conducting shell and a temperature control unit on the outside of the probe body, the problem of water droplet accumulation on the mirror surface of traditional chilled mirror dew point meters during high dew point gas detection is solved, and accurate detection of high dew point gases is achieved.
Patent Information
- Application Number
- CN202422736397.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-11
- Publication Date
- 2025-09-09
- Estimated Expiration
- 2034-11-11
AI Technical Summary
Traditional chilled mirror dew point meters cannot accurately detect high dew point gases because water droplets easily form on the mirror surface, making it impossible for the photoelectric detection system to identify the dew layer.
A heat-conducting shell is installed outside the probe body, and a first temperature control unit is set inside it to heat the test cavity to make the temperature higher than the gas dew point. Combined with the second temperature control unit in the heat-conducting base, a high temperature difference environment is maintained to prevent the formation of liquid condensation water, and condensation is only condensed on the mirror surface.
It effectively prevents condensed water from condensing in the test chamber, ensures that high dew point gas flows through the mirror in gaseous state, and realizes accurate detection of high dew point gas.
Smart Images
Figure CN223320339U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of cold mirror dew point meters, in particular to a high dew point gas detection sensor. Background Art
[0002] Gas dew point detection plays a key role in environmental monitoring and process control. Chilled mirror dew point meters are often the preferred detection equipment due to their high precision. The basic principle of a chilled mirror dew point meter is that gases with different water vapor contents will condense on the mirror surface at different temperatures. A photoelectric detection system is used to detect the dew layer and measure the temperature at the time of condensation, which is the dew point temperature of the gas.
[0003] As the dew point increases, the water content in the gas increases at a geometric rate. For example, when the dew point of the gas changes from 20°C to 25°C, the water content increases from 17g / m3 to 25g / m3. The change is 18g / m3, the increment is 1g / m3. When the gas dew point temperature changes from 90℃ to 95℃, its water content changes from 407g / m3 to 491g / m3, with an increment of up to 84g / m3. In the process of controlling the temperature of the mirror, the mirror temperature will inevitably be higher than the dew point and lower than the dew point. When the mirror temperature is lower than the dew point, water condenses quickly on the mirror. When measuring low-humidity dew point gas, due to the low absolute water content, it is not easy to form aggregated liquid water. However, when detecting high dew point gas, due to the high absolute humidity, aggregated water droplets are easily formed in the test chamber of the chilled mirror dew point meter. The water droplets converge around the mirror, filling or even submerging the entire mirror, resulting in the photoelectric detection system being unable to accurately identify the dew layer. This makes the traditional chilled mirror dew point meter unable to perform high dew point range calibration. Therefore, it is urgent to develop a chilled mirror dew point meter sensor suitable for high dew point gas detection. Utility Model Content
[0004] In order to solve the above-mentioned deficiencies in the prior art, the utility model provides a high dew point gas detection sensor.
[0005] The present invention provides a high dew point gas detection sensor, comprising a probe body, a photoelectric detection unit, and a mirror condensation unit. The probe body includes a test cavity for circulating the gas to be detected. The mirror condensation unit is mounted at the bottom of the test cavity, and the photoelectric detection unit is mounted at the top of the test cavity. A heat-conducting housing is mounted on the probe body outside the test cavity. The heat-conducting housing has an air inlet and an air outlet for communicating with the test cavity. A first temperature control unit is mounted within the heat-conducting housing for heating the heat-conducting housing. The heat-conducting housing with the first temperature control unit is mounted outside the probe body. The first temperature control unit heats the heat-conducting housing to raise the temperature within the test cavity to above the dew point of the gas to be detected. The greater the difference between the temperature within the test cavity and the dew point of the gas to be detected, the easier it is for water to evaporate, and the less likely it is for liquid condensation to form in the test cavity. This maintains a dry environment around the mirror, allowing the high dew point gas to flow through the mirror in a gaseous state, cooling and condensing only on the mirror, thereby completing the detection of the high dew point gas.
[0006] The probe body includes a detector and a thermal base connected sequentially from top to bottom. The test cavity is arranged transversely within the detector. A first mounting chamber for mounting a photoelectric detection unit is defined at the top of the detector. A second mounting chamber, communicating with the test cavity and for mounting a mirror condensation unit, is defined at the top of the thermal base. A second temperature control unit is installed within the thermal base to heat the thermal base. The second temperature control unit is added below the probe body. The thermal conductivity of the thermal base transfers heat from the second temperature control unit to the cooler, neutralizing heat loss from the heat-conducting housing due to ambient heat dissipation, thereby further maintaining a high temperature environment within the test cavity.
[0007] The heat-conducting shell is a cover structure with an opening at the lower end. The opening of the heat-conducting shell is provided with an internal thread portion, and the upper end of the heat-conducting seat is provided with an external thread portion that matches the internal thread portion.
[0008] A lower cavity is provided in the thermal base, and a control adapter board is provided in the lower cavity, which is electrically connected to the photoelectric detection unit, the mirror condensation unit and the second temperature control unit in sequence. The control adapter board is communicatively connected to the control system of the dew point meter via a main connector installed at the bottom of the thermal base.
[0009] The thermally conductive housing includes an upper cavity, which houses a temperature control circuit board electrically connected to the first temperature control unit. A first auxiliary connector electrically connected to the temperature control circuit board is mounted on the thermally conductive housing, and a second auxiliary connector electrically connected to the control adapter board is mounted on the bottom of the thermally conductive base. The first and second auxiliary connectors are communicatively connected via a plug connector. Through the communication connection between the first and second auxiliary connectors, the control signals of the first and second temperature control units are integrated onto a single control adapter board, thereby improving the integration of the sensor.
[0010] One end of the gas inlet is connected to a sample feed line, which is wrapped with a heating tape. The temperature of the heating tape is not lower than that of the sample gas. Wrapping the heating tape in the sample feed line can prevent premature condensation of the gas to be measured, thereby reducing the moisture content and affecting the measurement results.
[0011] The beneficial effects of the present utility model are as follows: the device installs a heat-conducting shell with a first temperature control unit on the outside of the probe body, and the first temperature control unit heats the heat-conducting shell to raise the temperature in the test cavity to above the dew point of the gas to be measured, thereby keeping the environment around the mirror in a dry state, thereby ensuring that the high dew-point gas flows through the mirror in a gaseous state, and cools and condenses only at the mirror surface, thereby completing the detection of high dew-point gas. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is a structural diagram of the utility model;
[0013] Figure 2 It is a cross-sectional schematic diagram of the utility model;
[0014] Figure 3 It is a disassembly diagram of the utility model;
[0015] Figure 4 This is a new working principle diagram of the present invention.
[0016] Figure numerals: 1. Probe body; 101. Detector; 102. Thermal seat; 103. External threaded portion; 104. Test cavity; 105. First installation cavity; 106. Second installation cavity; 107. Lower cavity; 108. Circuit channel; 2. Thermal shell; 201. Air inlet; 202. Air outlet; 203. Internal threaded portion; 204. Upper cavity; 3. Photoelectric detection unit; 4. Mirror condensation unit; 5. First temperature control unit; 6. Second temperature control unit; 7. Control adapter board; 8. Temperature control circuit board; 9. Main connector; 10. First auxiliary connector; 11. Second auxiliary connector; 12. Heating tape; 13. Temperature control equipment; 14. Control system. DETAILED DESCRIPTION
[0017] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention are clearly and completely described below in conjunction with the accompanying drawings. Other embodiments obtained by those skilled in the art without making any creative work should fall within the scope of protection of the present invention.
[0018] like Figure 1 and Figure 2 As shown, the utility model provides a high dew point gas detection sensor, including a probe body 1, a photoelectric detection unit 3 and a mirror condensation unit 4. The probe body 1 has a test cavity 104 for circulating the gas to be detected, the mirror condensation unit 4 is installed at the bottom of the test cavity 104, and the photoelectric detection unit 3 is installed at the top of the test cavity 104. The detection light emitted by the photoelectric detection unit 3 passes through the test cavity 104 and is projected onto the mirror surface of the mirror condensation unit 4, and receives the electrical signal generated by the light reflected by the mirror to detect the condensation state of the mirror condensation unit 4.
[0019] A heat-conducting housing 2 is mounted on the probe body 1 outside the test cavity 104. An air inlet 201 and an air outlet 202 are defined on the outside of the heat-conducting housing 2 for communicating with the test cavity 104. A first temperature control unit 5 is mounted within the heat-conducting housing 2 for heating the heat-conducting housing 2. By mounting the heat-conducting housing 2 with the first temperature control unit 5 outside the probe body 1, the first temperature control unit 5 heats the heat-conducting housing 2, thereby raising the temperature within the test cavity 104 to above the dew point of the gas being measured. The greater the difference between the temperature within the test cavity 104 and the dew point of the gas being measured, the easier it is for water to evaporate, and the less likely it is for liquid condensate to form in the test cavity 104. Specifically, in this embodiment, the temperature difference is generally maintained at approximately 10°C, thereby keeping the environment surrounding the mirror surface dry. High-dew-point gas flows through the mirror surface in a gaseous state, cooling and condensing only on the mirror surface, thereby completing the detection of high-dew-point gas.
[0020] like Figure 2As shown, the probe body 1 includes a detector 101 and a thermal seat 102 connected in sequence from top to bottom, the test cavity 104 is arranged in the detector 101 along the horizontal direction, and a first installation cavity 105 for installing the photoelectric detection unit 3 is provided on the top of the detector 101, and a second installation cavity 106 connected to the test cavity 104 and for installing the mirror condensation unit 4 is provided on the top of the thermal seat 102. In this embodiment, the photoelectric detection unit 3 and the mirror condensation unit 4 are existing technologies, wherein the photoelectric detection unit includes an emitting end for emitting detection light and a receiving end for receiving reflected light, and the mirror condensation unit 4 includes a lens and a refrigeration stack fixed in the second installation cavity 106 from top to bottom, and a platinum resistance temperature sensor for detecting the lens temperature is embedded in the cold end of the refrigeration stack. At the same time, in order to ensure the sealing of the second installation cavity 106, the second installation cavity 106 is filled with glue sealing.
[0021] Further preferably, to neutralize heat loss from the thermally conductive housing 2 due to ambient heat dissipation, thereby further maintaining the high temperature difference between the dew point of the test chamber 104 and the measured gas, a second temperature control unit 6 is installed within the thermally conductive base 102 to heat the thermally conductive base 102. In this embodiment, the first temperature control unit 5 and the second temperature control unit 6 are each composed of at least two heating tubes and a thermocouple. The heating tubes and thermocouple are respectively embedded and sealed within the thermally conductive housing 2 / thermal conductive base 102. The temperature value fed back by the thermocouple controls the on / off switching of the corresponding heating tube, thereby completing the temperature control operation.
[0022] Further preferably, the heat-conducting shell 2 and the probe body 1 in this embodiment are made of aluminum alloy to ensure the thermal conductivity of the entire shell part, which is beneficial to the heating control of the test cavity 104 environment. In other embodiments, stainless steel can also be used.
[0023] like Figure 3 As shown, in this embodiment, the heat-conducting shell 2 is a cover structure with an opening at the lower end. The opening of the heat-conducting shell 2 has an internal threaded portion 203, and the upper end of the heat-conducting seat 102 has an external threaded portion 103 that cooperates with the internal threaded portion 203. The threaded cooperation between the external threaded portion 103 and the internal threaded portion 203 realizes the detachable separation of the heat-conducting shell 2 and the heat-conducting seat 102. The probe body 1 separated from the heat-conducting shell 2 can be used for the detection of normal gas, ensuring the adaptability of the sensor.
[0024] like Figure 2As shown, a lower cavity 107 is provided in the thermal base 102, and a control adapter board 7 is provided in the lower cavity 107, which is electrically connected to the photoelectric detection unit 3, the mirror condensation unit 4 and the second temperature control unit 6 in sequence. Preferably, a circuit channel 108 for the corresponding leads of the photoelectric detection unit 3 and the mirror condensation unit 4 to pass through is opened in the detector 101 and the thermal base 102, and the circuit channel 108 is sealed by glue; a lower cover for sealing the lower cavity 107 is installed at the bottom of the thermal base 102, and a direct connector is installed on the lower cover, such as Figure 4 As shown, the control adapter board 7 is communicatively connected to the control system 14 of the dew point meter via the main connector 9; an upper cavity 204 is provided in the heat-conducting housing 2, and a temperature control circuit board 8 electrically connected to the first temperature control unit 5 is provided in the upper cavity 204. An upper cover for sealing the upper cavity 204 is installed on the top of the heat-conducting housing 2, and a first auxiliary connector 10 is installed on the upper cover. The temperature control circuit board 8 is electrically connected to the first auxiliary connector 10 via a needle electrode. In order to improve the integration of the sensor, a second auxiliary connector 11 is installed on the lower cover. The second auxiliary connector 11 is electrically connected to the control adapter board 7 via a needle electrode, as shown in FIG. Figure 4 As shown, the first auxiliary connector 10 and the second auxiliary connector 11 are communicatively connected via a plug connector, so that the control signals of the first temperature control unit 5 and the second temperature control unit 6 are integrated on a control adapter board 7 .
[0025] like Figure 1 and Figure 4 As shown, in order to avoid premature condensation of the gas to be measured, thereby reducing the water content and affecting the accuracy of the measurement results, one end of the air inlet 201 is connected to a sampling pipeline, and the outside of the sampling pipeline is wrapped with a heating tape 12. Preferably, the heating tape 12 is electrically connected to the temperature control device 13 so that the temperature of the heating tape 12 is not lower than the temperature of the inlet gas.
[0026] When implementing the above technical solution, the sensor is connected to the control system 14 of the dew point meter through the communication connector, the heating cable 12 is connected to the temperature control device 13, the dew point prediction range of the gas to be measured is 80-90°C, the heating cable 12, the heat-conducting shell 2 and the heat-conducting seat 102 are all heated to 100°C, so that the temperature in the sampling pipeline and the test cavity 104 is higher than the dew point temperature of the gas to be measured by more than 10°C, and the gas to be measured enters the sensor from the air inlet 201 and passes over the mirror. At the same time, the temperature of the refrigeration stack of the mirror condensation unit 4 is controlled. When the temperature of the mirror is When the temperature is lower than the dew point, condensation is easily formed due to the high water content of the high dew point gas. The test chamber 104 has a temperature difference of more than 10°C, which causes the formed condensation to evaporate quickly, effectively preventing condensation in the test chamber 104. As a result, cooling and condensation only occur on the mirror surface, forming a stable dew layer. The control system 14 receives the stable voltage signal fed back from the photoelectric detection unit 3 to determine the equilibrium state of the detection. At this time, the mirror surface temperature fed back by the platinum resistance temperature sensor is used to obtain the dew point value of the high dew point gas, thereby realizing the calibration of this sensor in the high dew point range.
Claims
1. A high dew point gas detection sensor, comprising a probe body, a photoelectric detection unit, and a mirror condensation unit, wherein the probe body has a test cavity for circulating the gas to be detected, the mirror condensation unit is installed at the bottom of the test cavity, and the photoelectric detection unit is installed at the top of the test cavity, characterized in that: A heat-conducting shell is installed on the probe body outside the test cavity. An air inlet and an air outlet for communicating with the test cavity are opened on the outside of the heat-conducting shell. A first temperature control unit is installed in the heat-conducting shell to heat the heat-conducting shell.
2. A high dew point gas detection sensor according to claim 1, characterized in that: The probe body includes a detector and a thermal conductive seat connected in sequence from top to bottom. The test cavity is arranged in the detector along the horizontal direction. A first installation cavity for installing a photoelectric detection unit is provided on the top of the detector. A second installation cavity connected to the test cavity and for installing a mirror condensation unit is provided on the top of the thermal conductive seat. A second temperature control unit is installed in the thermal conductive seat to heat the thermal conductive seat.
3. A high dew point gas detection sensor according to claim 2, characterized in that: The heat-conducting shell is a cover structure with an opening at the lower end. The opening of the heat-conducting shell is provided with an internal thread portion, and the upper end of the heat-conducting seat is provided with an external thread portion that matches the internal thread portion.
4. A high dew point gas detection sensor according to claim 2, characterized in that: A lower cavity is provided in the thermal base, and a control adapter board is provided in the lower cavity, which is electrically connected to the photoelectric detection unit, the mirror condensation unit and the second temperature control unit in sequence. The control adapter board is communicatively connected to the control system of the dew point meter via a main connector installed at the bottom of the thermal base.
5. A high dew point gas detection sensor according to claim 4, characterized in that: An upper cavity is provided in the heat-conducting housing, and a temperature control circuit board electrically connected to the first temperature control unit is provided in the upper cavity. A first auxiliary connector electrically connected to the temperature control circuit board is installed on the heat-conducting housing, and a second auxiliary connector electrically connected to the control adapter board is installed at the bottom of the heat-conducting seat. The first auxiliary connector and the second auxiliary connector are communicatively connected via a plug connector.
6. A high dew point gas detection sensor according to any one of claims 1 to 5, characterized in that: One end of the air inlet is connected to a sampling pipeline, and the outside of the sampling pipeline is wrapped with a heating tape, and the temperature of the heating tape is not lower than the temperature of the sampling gas.