Temperature control system of high-precision laser gas analyzer

Abstract

The invention discloses a temperature control system of a high-precision laser gas analyzer. The temperature control system comprises an analyzer, a high-temperature box is arranged at the upper part of the analyzer, a measuring cell, a measuring cell heating block, a measuring cell bracket, a high-temperature box heat insulating layer and a measuring cell temperature measuring element are arranged in the high-temperature box, and the measuring cell heating block is mounted on the measuring cell and is tightly attached to the measuring cell; the measuring cell temperature measuring element is installed on the measuring cell and is not in direct contact with the measuring cell heating block. According to the temperature control system of the high-precision laser gas analyzer, temperature control of each module of the laser gas analyzer is realized, the detection precision of the laser gas analyzer is improved, and the application scene of the laser gas analyzer is expanded.

Description

Technical Field

[0001] The invention relates to the technical field of gas analysis, and in particular to a temperature control system of a high-precision laser gas analyzer. Background Art

[0002] With the rise of emerging industries such as semiconductors, chips, and intelligent manufacturing, and with the demand for environmental protection and the continuous development and sophistication of modern industrial technology, companies' demand for environmental monitoring and process control precision is also growing.

[0003] The core components of the laser gas analyzer are the laser, detector and measuring cell. The scanning wavelength of the laser is determined by the temperature and driving current of the laser. The more stable the temperature and current of the laser, the more stable the start and end wavelengths of the laser. The ambient temperature of the laser has a greater impact on the temperature of the laser. The sensitivity of the detector is determined by the temperature of the detector. The lower the temperature of the detector, the higher the sensitivity of the detector and the higher the signal-to-noise ratio. When the ambient temperature of the detector is lower, the temperature that the detector can reach is lower. In order to ensure the phase stability and chemical properties of the components to be measured, it is usually necessary to control the temperature of the measuring cell within a relatively high range. At the same time, in order to ensure the stability of the main optical path, that is, the stability of the optical-mechanical structure of the measuring cell, it is also necessary to ensure the relative stability of the temperature of the measuring cell. Therefore, how to meet the different temperature requirements of the laser, detector and measuring cell, and how to eliminate the mutual influence of the temperature among the three are the key to a high-precision laser gas analyzer. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above-mentioned problems existing in the temperature control system of the existing high-precision laser gas analyzer, the present invention is proposed.

[0006] Therefore, the object of the present invention is to provide a temperature control system for a high-precision laser gas analyzer, which eliminates the temperature interference between different modules inside the laser gas analyzer and improves the measurement accuracy of the laser gas analyzer.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a temperature control system for a high-precision laser gas analyzer, comprising an analyzer;

[0008] A high temperature box is provided on the upper part of the analyzer, and the interior of the high temperature box contains a measuring cell, a measuring cell heating block, a measuring cell bracket, a high temperature box insulation layer and a measuring cell temperature measuring element. The measuring cell heating block is installed on the measuring cell and fits tightly with the measuring cell; the measuring cell temperature measuring element is installed on the measuring cell and does not directly contact the measuring cell heating block;

[0009] An optical box is arranged at the lower left part of the analyzer, and the interior of the optical box includes a laser module, a main control & acquisition board, a Peltier, a hot end fin, a hot end fan, a cold end fin, a cold end fan, an optical box insulation layer and an optical box temperature measuring element; the laser module includes a laser 1, a laser 2, a laser 3, a dichroic mirror 1, a dichroic mirror 2 and a reflector 1, and the laser 1, the laser 2 and the laser 3 are encapsulated with a Peltier temperature control chip; the Peltier is located in the middle of the optical box insulation layer, the hot end of the Peltier faces the inner side of the optical box, the hot end of the Peltier and the hot end fin, and the cold end and the cold end fin should fit tightly, and the surface is coated with thermal conductive silicone grease; the hot end fan and the cold end fan are respectively installed on the corresponding fins, and the wind direction is towards the fin direction; the optical box temperature measuring element is installed at the air outlet of the hot end fin and does not contact the hot end fin;

[0010] An electric control box is provided at the lower right part of the analyzer; the electric control box contains a detector module, a temperature control module, and a power supply module; the detector module includes a detector 1 and a detector 2; a Peltier temperature control chip is encapsulated inside the detector 1 and the detector 2, and the temperature control of the laser 1, the laser 2, the laser 3, the detector 1, and the detector 2 is realized by controlling the Peltier temperature control chip inside the main control & acquisition board;

[0011] The high temperature box, the optical box and the electric control box are connected through an optical path conversion module, which includes a second reflector, a third reflector, a fourth reflector, a third dichroic mirror, a fifth reflector and a purge port, and the purge port is located at the optical box position.

[0012] As a preferred solution of the temperature control system of the high-precision laser gas analyzer of the present invention, the internal temperature range of the high-temperature box is 50-250°C.

[0013] As a preferred solution of the temperature control system of the high-precision laser gas analyzer described in the present invention, the material of the measuring cell bracket is a plastic with low thermal conductivity and heat resistance, including one or more of polyphenylene sulfide (PPS), polyethersulfone resin (PES), polytetrafluoroethylene (PTFE), soluble polytetrafluoroethylene (PFA), polyetheretherketone (PEEK), and polyimide (PAI).

[0014] As a preferred solution of the temperature control system of the high-precision laser gas analyzer described in the present invention, the thermal conductivity of the high-temperature box insulation layer is lower than 0.04W / (m·K), and includes aerogel, glass fiber, and air; the thickness of the high-temperature box insulation layer is greater than or equal to 20mm.

[0015] As a preferred solution of the temperature control system of the high-precision laser gas analyzer of the present invention, the internal temperature range of the optical box is 45-55°C.

[0016] As a preferred solution of the temperature control system of the high-precision laser gas analyzer described in the present invention, the thermal conductivity of the optical box insulation layer should be lower than 0.04W / (m·K), including aerogel, glass fiber, and air; the thickness of the optical box insulation layer should be greater than or equal to 10mm.

[0017] As a preferred solution of the temperature control system of the high-precision laser gas analyzer described in the present invention, the temperature control module controls the temperature of the high-temperature box through a relay, and the temperature control accuracy is 0.1°C; the temperature control module controls the temperature of the optical box through voltage regulation, and the temperature control accuracy is 0.05°C.

[0018] As a preferred solution of the temperature control system of the high-precision laser gas analyzer described in the present invention, the outer shell material of the optical path conversion module is a plastic with low thermal conductivity and heat resistance, including one or more of polyphenylene sulfide (PPS), polyethersulfone resin (PES), polytetrafluoroethylene (PTFE), soluble polytetrafluoroethylene (PFA), polyetheretherketone (PEEK), and polyimide (PAI).

[0019] Beneficial effects of the present invention: The temperature control system of the high-precision laser gas analyzer provided by the present invention realizes separate temperature control of each module of the laser gas analyzer, improves the detection accuracy of the laser gas analyzer, and expands the application scenarios of the laser gas analyzer. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0021] Figure 1 A schematic diagram of a temperature control system of a high-precision laser gas analyzer proposed by the present invention;

[0022] Figure 2 A wind direction diagram of a temperature control system of a high-precision laser gas analyzer proposed by the present invention;

[0023] Figure 3 This is a light path diagram of the temperature control system of a high-precision laser gas analyzer proposed by the present invention. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0025] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0026] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0027] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0028] Reference Figure 1-Figure 3 A temperature control system for a high-precision laser gas analyzer includes a high-temperature box 2, an electric control box 11, an optical box 20, and an optical path conversion module 32. The high-temperature box 2 is located at the upper part of the analyzer, the optical box 20 and the electric control box 11 are located at the lower left and lower right parts of the analyzer respectively, and the optical path conversion module 32 runs through the high-temperature box 2, the optical box 20, and the electric control box 11. The high-temperature box 2, the electric control box 11, the optical box 20, and the optical path conversion module 32 are all installed on the same analyzer base.

[0029] The high temperature box 2 contains a measuring cell 4, a measuring cell heating block 3, a measuring cell bracket 5, a high temperature box insulation layer 35, and a measuring cell temperature measuring element 1. The heating source in the high temperature box 2 is the measuring cell heating block 3, which is installed on the measuring cell 4 and fits tightly with the measuring cell 4. The internal temperature control range of the high temperature box 2 is 50-250°C. The specific control temperature is determined by the actual application scenario and the measurement component, and the temperature control accuracy is 0.1°C. The measuring cell 4 is directly installed on the base of the analyzer through the measuring cell bracket 5. The measuring cell bracket 5 runs through the bottom of the high temperature box 2. At the same time, it is necessary to ensure that the measuring cell 4 and the measuring cell heating block 3 do not contact the outer shell of the high temperature box 2. The material of the measuring cell bracket 5 should be a plastic with low thermal conductivity and heat resistance, preferably polyphenylene sulfide (PPS), polyethersulfone resin (PES), polytetrafluoroethylene (PTFE), soluble polytetrafluoroethylene (PFA), polyetheretherketone (PEEK), and polyimide (PAI), to ensure that the heat of the measuring cell will not be conducted to other modules through the measuring cell bracket 5 and the analyzer base, causing thermal interference. The thickness of the high temperature box insulation layer 35 should be greater than or equal to 20mm, and its thermal conductivity should be lower than 0.04W / (m·K), preferably aerogel, glass fiber, and air, which can reduce the escape of heat inside the high temperature box 2. The temperature control of the high temperature box 2 is controlled by the temperature control module 12, and the temperature regulation control form is a relay form. The measuring cell temperature measuring element 1 is installed on the measuring cell 4 but is not in direct contact with the measuring cell heating block 3.

[0030] The optical box 20 contains a laser module 29, a main control & acquisition board 21, a Peltier 16, a hot end fin 17, a hot end fan 18, a cold end fin 15, a cold end fan 14, an optical box insulation layer 19, and an optical box temperature measuring element 22; the electric control box 11 contains a detector module 10, a temperature control module 12, and a power supply module 13. Among them, the Peltier 16, the hot end fin 17, the hot end fan 18, the cold end fin 15, the cold end fan 14, and the optical box insulation layer 19 are shared by the optical box 20 and the electric control box 11, and only control the internal temperature of the optical box 20. The electric control box part only cools down but does not control the temperature. The internal temperature range of the optical box 20 is 45-55°C. The specific temperature is determined by the actual application scenario, and the temperature control accuracy is 0.05°C. The temperature measurement accuracy of the optical box temperature measuring element 22 should reach 0.01°C to ensure that the temperature control accuracy reaches the level of 0.05°C. The optical box temperature measuring element 22 is installed at the air outlet of the hot end fin 17 and does not contact the hot end fin 17. The optical box 20 contains a heat insulation layer, and the electrical control box 11 does not contain a heat insulation layer. The thickness of the optical box heat insulation layer 19 should be greater than or equal to 10mm, and the thermal conductivity should be lower than 0.04W / (m·K). It is preferably aerogel, glass fiber, and air. In this way, the internal temperature control of the optical box 20 can be ensured not to be affected by the external environment, and the hot end and cold end of the Peltier 16 can be isolated as much as possible to improve the working efficiency of the Peltier. The Peltier 16 is located in the middle of the optical box heat insulation layer 19, the hot end of the Peltier faces the inner side of the optical box 20, and the cold end faces the inner side of the electrical control box 11. The hot end of the Peltier 16 and the hot end fin 17, and the cold end and the cold end fin 15 should fit tightly, and the surface is coated with thermal conductive silicone grease. The hot end fan 18 and the cold end fan 14 are respectively installed on the corresponding fins, and the wind direction is toward the fin direction, refer to Figure 2 In the optical box 20, the hot end fan 18 blows the wind to the hot end fin 17, takes away the heat on the fin, blows it out from the upper and lower ends of the fin, circulates along the box body and returns to the fan; in the electric control box 11, the cold end fan 14 blows the wind to the cold end fin 15, blows it out from the upper and lower ends of the fin, circulates along the box body and returns to the fan, so that the air in the box and the cold end fin can fully exchange heat, and the temperature in the electric control box 11 can be reduced. The temperature control of the optical box 20 is controlled by the temperature control module 12, and the working power of the Peltier is adjusted by adjusting the power supply voltage to the Peltier, thereby realizing temperature control.

[0031] Laser 1 27, laser 2 25, laser 3 23 in the laser module 29 and detector 1 9 and detector 2 8 in the detector module 10 are all encapsulated with Peltier temperature control chips. The temperature control of the laser and the detector is achieved through the interaction between the main control & acquisition board 21 and the Peltier temperature control chips inside the laser and the detector.

[0032] The optical path conversion module 32 includes a reflector 2 34, a reflector 3 33, a reflector 4 31, a dichroic mirror 3 7, a reflector 5 6, and a purge port 30. It is mainly to realize the conversion of the optical path of the analyzer and achieve the purpose of measurement. The outer shell material of the optical path conversion module 32 should be a plastic with low thermal conductivity and heat resistance, preferably polyphenylene sulfide (PPS), polyethersulfone resin (PES), polytetrafluoroethylene (PTFE), soluble polytetrafluoroethylene (PFA), polyetheretherketone (PEEK), and polyimide (PAI). This is to prevent the internal temperatures of the three boxes from interfering with each other through the optical path conversion module 32. The purge port 30 is located inside the optical box 20. First, it can ensure the cleanliness of the external optical path, reduce the interference of the external optical path, and improve the measurement accuracy of the analyzer; second, it prevents the high-temperature gas inside the high-temperature box 2 from entering the optical box 20 and the electrical control box 11 through convection.

[0033] Reference Figure 3 The optical path of the high-precision laser gas analyzer during operation is shown in the figure: the laser 27 emits a laser, which is reflected after reaching the dichroic mirror 28, reflected after reaching the reflector 2 34, enters the measuring cell 4, and is emitted after multiple reflections in the measuring cell 4 to reach the reflector 3 33, and is reflected to the reflector 4 31, and then is reflected by the reflector 4 31 to the dichroic mirror 3 7, and is reflected by the dichroic mirror 3 7 into the detector 1 9 to complete detection and analysis; the laser 25 emits a laser, which is reflected after reaching the dichroic mirror 2 26, transmitted after reaching the dichroic mirror 1 28, reflected after reaching the reflector 2 34, enters the measuring cell 4, and is emitted after multiple reflections in the measuring cell 4 to reach the reflector 3 33. After reaching the measuring cell 4, after being reflected multiple times in the measuring cell 4, it is emitted and reaches the reflector three 33, and then is reflected to the reflector four 31, and then is reflected by the reflector four 31 to the dichroic mirror three 7, and then is transmitted, and after reaching the reflector five 6, it is reflected into the detector two 8 to complete the detection and analysis. The laser three 23 emits a laser, which is reflected after reaching the reflector one 24, and then is transmitted after reaching the dichroic mirror two 26, and then is transmitted after reaching the dichroic mirror one 28, and then is reflected after reaching the reflector two 34, and enters the measuring cell 4. After being reflected multiple times in the measuring cell 4, it is emitted and reaches the reflector three 33, and then is reflected to the reflector four 31, and then is reflected by the reflector four 31 to the dichroic mirror three 7, and then is transmitted, and after reaching the reflector five 6, it is reflected into the detector two 8 to complete the detection and analysis.

[0034] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A temperature control system for a high-precision laser gas analyzer, comprising an analyzer, characterized in that: A high temperature box (2) is arranged on the upper part of the analyzer, and the high temperature box (2) contains a measuring cell (4), a measuring cell heating block (3), a measuring cell bracket (5), a high temperature box insulation layer (35) and a measuring cell temperature measuring element (1). The measuring cell heating block (3) is installed on the measuring cell (4) and is tightly fitted with the measuring cell (4); the measuring cell temperature measuring element (1) is installed on the measuring cell (4) and is not in direct contact with the measuring cell heating block (3); An optical box (20) is provided at the lower left part of the analyzer, and the optical box (20) contains a laser module (29), a main control and acquisition board (21), a Peltier (16), a hot end fin (17), a hot end fan (18), a cold end fin (15), a cold end fan (14), an optical box insulation layer (19) and an optical box temperature measuring element (22); the laser module (29) contains a laser 1 (27), a laser 2 (25), a laser 3 (23), a dichroic mirror 1 (28), a dichroic mirror 2 (26) and a reflector 1 (24); the laser 1 (27), Laser 2 (25) and laser 3 (23) are internally encapsulated with a Peltier temperature control chip; the Peltier (16) is located in the middle of the optical box insulation layer (19), the hot end of the Peltier faces the inner side of the optical box (20), the hot end of the Peltier and the hot end fin (17), the cold end and the cold end fin (15) should fit tightly, and the surface is coated with thermal grease; the hot end fan (18) and the cold end fan (14) are respectively installed on the corresponding fins, and the wind direction is toward the fin direction; the optical box temperature measuring element (22) is installed at the air outlet of the hot end fin (17) and does not contact the hot end fin (17); An electric control box (11) is provided at the lower right part of the analyzer; the electric control box (11) contains a detector module (10), a temperature control module (12), and a power module (13); the detector module (10) contains a detector 1 (9) and a detector 2 (8); the detector 1 (9) and the detector 2 (8) are encapsulated with a Peltier temperature control chip; the temperature control of the laser 1 (27), the laser 2 (25), the laser 3 (23), the detector 1 (9), and the detector 2 (8) is achieved by controlling the Peltier temperature control chip inside the main control & acquisition board (21); The high temperature box (2), the optical box (20) and the electric control box (11) are connected through an optical path conversion module (32), the optical path conversion module (32) comprising a second reflector (34), a third reflector (33), a fourth reflector (31), a third dichroic mirror (7), a fifth reflector (6), and a purge port (30), and the purge port (30) is located at the optical box (20).

2. The temperature control system of the high-precision laser gas analyzer according to claim 1, characterized in that: The internal temperature of the high temperature box (2) ranges from 50 to 250°C.

3. The temperature control system of the high-precision laser gas analyzer according to claim 2, characterized in that: The material of the measuring cell bracket (5) is a heat-resistant plastic with low thermal conductivity, including one or more of polyphenylene sulfide (PPS), polyethersulfone resin (PES), polytetrafluoroethylene (PTFE), soluble polytetrafluoroethylene (PFA), polyetheretherketone (PEEK), and polyimide (PAI).

4. The temperature control system of the high-precision laser gas analyzer according to claim 3 is characterized in that: The high temperature box heat insulation layer (35) has a thermal conductivity lower than 0.04 W / (m·K) and comprises aerogel, glass fiber, and air; the thickness of the high temperature box heat insulation layer (35) is greater than or equal to 20 mm.

5. The temperature control system of the high-precision laser gas analyzer according to claim 1, characterized in that: The internal temperature of the optical box (20) ranges from 45°C to 55°C.

6. The temperature control system of the high-precision laser gas analyzer according to claim 5, characterized in that: The thermal conductivity of the optical box heat insulation layer (19) is lower than 0.04 W / (m·K), and comprises aerogel, glass fiber, and air; the thickness of the optical box heat insulation layer (19) is greater than or equal to 10 mm.

7. The temperature control system of the high-precision laser gas analyzer according to claim 1, characterized in that: The temperature control module (12) controls the temperature of the high temperature box in the form of a relay, with a temperature control accuracy of 0.1°C; the temperature control module (12) controls the temperature of the optical box in the form of a voltage regulation, with a temperature control accuracy of 0.05°C.

8. The temperature control system of the high-precision laser gas analyzer according to claim 1, characterized in that: The outer shell material of the optical path conversion module (32) is a heat-resistant plastic with low thermal conductivity, including one or more of polyphenylene sulfide (PPS), polyethersulfone resin (PES), polytetrafluoroethylene (PTFE), soluble polytetrafluoroethylene (PFA), polyetheretherketone (PEEK), and polyimide (PAI).

Images