Multi-channel refrigerant leakage detector

Abstract

The utility model relates to the technical field of gas detection, in particular to a multi-channel refrigerant leakage detector. The multi-channel refrigerant leakage detector comprises a gas absorption chamber. Two ends of the gas absorption chamber are respectively provided with an infrared blackbody light source and a multi-channel infrared detector. Wherein the multi-channel infrared detector comprises a reference channel and at least two detection channels, and optical filters corresponding to the detection channels are respectively configured to be suitable for detecting any one of carbon dioxide, hydrocarbon refrigerants and halogen refrigerants; the detection channels are suitable for detecting different types of refrigerants; and the control unit is connected with the infrared blackbody light source and the multi-channel infrared detector and is used for generating a detection result according to a detection signal of the multi-channel infrared detector. According to the multi-channel refrigerant leakage detector, leakage of various refrigerants can be conveniently and accurately detected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas detection, in particular to a multi-channel refrigerant leakage detector. BACKGROUND

[0002] A gas sniffer is a device used for detecting and analyzing gas leakage, widely used in industries, environmental protection, safety and other fields. It can detect a variety of gases, including but not limited to flammable gas, toxic gas, volatile organic compounds (VOCs) and the like.

[0003] In the gas sniffer, the infrared gas sniffer using non-dispersive infrared technology (NDIR, Non-Dispersive InfraRed) for gas detection is widely used in various gas detection scenarios due to its advantages of not directly contacting with the gas and long service life.

[0004] In the prior art, when detecting the leakage of refrigerant for some equipment, due to the different types of refrigerant gas, it is often necessary to replace the corresponding gas sniffer for detection or replace the detection sensor in the gas sniffer according to the type of the detected refrigerant, which is very inconvenient and not intelligent. SUMMARY

[0005] In order to solve the problems existing in the prior art, the purpose of the present application is to provide a multi-channel refrigerant leakage detector which can accurately detect the leakage of multiple refrigerants without replacing the sensor.

[0006] To achieve the above purpose, the present application provides a multi-channel refrigerant leakage detector, comprising:

[0007] A gas absorption chamber, two ends of the gas absorption chamber are respectively provided with an infrared blackbody light source and a multi-channel infrared detector; wherein the multi-channel infrared detector comprises one reference channel and at least two detection channels, the filter corresponding to each detection channel is respectively configured to be suitable for detecting any one of carbon dioxide, hydrocarbon refrigerant and halogen refrigerant; the types of refrigerants suitable for detection by each detection channel are different;

[0008] A control unit connected with the infrared blackbody light source and the multi-channel infrared detector, used for generating a detection result according to the detection signal of the multi-channel infrared detector.

[0009] Further, the multi-channel infrared detector is a four-channel infrared detector, and the four-channel infrared detector comprises a reference channel, a carbon dioxide detection channel, a hydrocarbon refrigerant detection channel and a halogen refrigerant detection channel.

[0010] The filter corresponding to the reference channel has a center wavelength of 3.95 μm; the filter corresponding to the carbon dioxide detection channel has a center wavelength of 4.26 μm; the filter corresponding to the hydrocarbon refrigerant detection channel has a center wavelength of 3.4 μm; and the filter corresponding to the halogen refrigerant detection channel has a center wavelength of 8-14 μm.

[0011] Furthermore, a front cover and a rear cover are respectively provided at both ends of the gas absorption chamber. A first PCB board is provided on the front cover, and the infrared blackbody light source is provided on the first PCB board. A second PCB board is provided on the rear cover, and the multi-channel infrared detector is provided on the second PCB board. A third PCB board is provided on the upper part of the gas absorption chamber, and the control unit is provided on the third PCB board.

[0012] A further connection is provided between the multi-channel infrared detector and the control unit:

[0013] A switch, connected to the multi-channel infrared detector and the control unit, is used to select the channel through which the multi-channel infrared detector outputs the detection signal;

[0014] A filtering and amplification circuit, connected to the switch, is used to filter and amplify the detection signal before outputting it to the control unit.

[0015] Furthermore, it also includes:

[0016] An acceleration sensor, connected to the control unit, is used to detect the acceleration of the refrigerant leak detector.

[0017] Furthermore, the infrared blackbody light source is configured to be driven by a constant power drive circuit.

[0018] Furthermore, the constant power drive circuit includes:

[0019] The DC-DC chip includes an EN terminal, a PGND terminal, an OC terminal, a VCC terminal, an LX terminal, a NC terminal, an FB terminal, and a GND terminal. The PGND terminal is connected to the power supply node via a seventh capacitor; the PGND terminal is also connected to the GND node; the OC terminal is connected to the GND node via a tenth resistor; the VCC terminal is connected to the power supply node; the EN terminal is connected to the power supply node and is controlled by the control unit; the LX terminal is connected to the anode of the first diode D1, and the cathode of the first diode is connected to the FB terminal via a third capacitor; the NC terminal is left floating; the FB terminal is grounded via a sampling resistor; and the GND terminal is connected to the GND node.

[0020] The first capacitor is located between the power node and the GND node.

[0021] The fourth capacitor is connected in parallel across the seventh capacitor;

[0022] a first inductor, disposed between the power supply node and the anode of the first diode;

[0023] a monitoring chip, comprising a GND terminal, an IN terminal, two NC terminals, a VCC terminal, a POUT terminal, an RS- terminal and an RS+ terminal; wherein the GND terminal is connected with the GND node; the VCC terminal is connected with the power supply node; a second capacitor is further disposed between the GND terminal and the VCC terminal; the IN terminal is connected with the GND node through a ninth capacitor; the POUT terminal is connected with the FB terminal of the DC-DC chip through a first resistor; the RS- terminal is connected with the GND node through an eleventh resistor and a ninth resistor; the RS+ terminal is connected with the cathode of the first diode;

[0024] a thirty-fifth resistor, having two ends connected with the cathode of the first diode and a light source voltage node respectively; the light source voltage node is further connected with the RS- terminal; a fifth capacitor and a sixth capacitor are further connected in parallel between the light source voltage node and the GND node.

[0025] Further, the gas absorption chamber is wrapped by two shielding covers.

[0026] Further, the control unit is further connected with a Bluetooth module, which is used for transmitting the detection result through Bluetooth.

[0027] The multi-channel refrigerant leakage detector of the present application can detect three kinds of refrigerants without replacing the detection sensor by using a multi-channel infrared detector configured with different specifications of filters.

[0028] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art, and will be learned from practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate the present application, and are used to explain the present application, and do not constitute a limitation on the present application. In the drawings:

[0030] Fig. 1 It is a principle block diagram of the multi-channel refrigerant leakage detector of the present application embodiment 1;

[0031] Fig. 2 It is a structure schematic diagram of the gas absorption chamber of the present application embodiment 1;

[0032] Fig. 3 It is a structure schematic diagram of the constant power driving circuit of the present application embodiment 1;

[0033] BRIEF DESCRIPTION OF DRAWINGS: 1-First PCB board, 2-Infrared blackbody light source, 3-Side foam, 4-First shielding cover, 5-Third PCB board, 6-Gas absorption chamber, 7-Bottom foam, 8-Second shielding cover, 9-Top foam, 10-Sealing ring, 11-Multi-channel infrared detector, 12-Second PCB board, 13-Screw, 14-Back cover, 100-Control unit, 102-Switch, 103-Filtering and amplifying circuit, 105-Communication unit, 106-Constant power driving circuit, 107-Acceleration sensor. DETAILED DESCRIPTION

[0034] Embodiments of the present application will be described in more detail by referring to the drawings. Although certain embodiments of the present application are shown in the drawings, it is understood that the present application can be embodied in various forms and should not be interpreted as being limited to the embodiments set forth herein, but rather, these embodiments are provided so that the present application can be more thoroughly and completely understood. It is understood that the drawings and embodiments of the present application are for exemplary purposes only and are not intended to limit the scope of the present application.

[0035] It is understood that each of the steps recited in the method embodiments of the present application can be performed in different orders and / or in parallel. In addition, the method embodiments can include additional steps and / or omit performing the steps shown. The scope of the present application is not limited in this regard.

[0036] The term "comprising" and variations thereof as used herein are open-ended, that is, "comprising but not limited to." The term "based on" means "based, at least in part, on." The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments." Related terms are defined in the description that follows.

[0037] It should be noted that the modification of "one", "multiple" mentioned in this application is illustrative but not restrictive, and those skilled in the art should understand that unless the context clearly indicates otherwise, it should be understood as "one or more". "Multiple" should be understood as two or more. Hydrocarbon refrigerants, Hydrocarbon refrigerants are a class of natural refrigerants that use propane (R290), isobutane (R600A), propylene (R1270) and other hydrocarbons as the main component. This kind of refrigerant has been concerned in recent years because of its excellent environmental protection characteristics: its ozone layer destruction potential (ODP) is zero, and its global warming potential (GWP) is extremely low (such as R290, whose GWP is only 3, far lower than the 2088 of traditional refrigerant R410A), fully meeting the requirements of international environmental protection regulations for reducing greenhouse gas emissions. In addition, hydrocarbon refrigerants have excellent thermodynamic performance and high energy efficiency ratio (COP), which can significantly reduce system energy consumption and are suitable for household refrigerators, small air conditioners and commercial refrigeration equipment. However, its highly flammable and explosive characteristics (such as R290 explosion limit of 2.1% ~ 9.5%) pose strict requirements on safety design. The equipment needs to use explosion-proof electrical components, strict sealing process, and limit the charge amount (such as IEC standard stipulates that the charge amount of household refrigerator is not more than 150 grams). Despite the safety challenges, hydrocarbon refrigerants have been applied on a large scale in Europe, India and other places, and with the progress of technology, they are gradually expanding to the cold chain logistics and heat pump fields.

[0038] Halogen refrigerants, Halogen refrigerants are a class of compounds containing halogen elements (such as fluorine, chlorine, bromine, etc.), which have been widely used in refrigeration and air conditioning systems. This kind of refrigerant mainly includes chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) etc. Among them, R22 (difluoromonochloromethane) is one of the most common halogen refrigerants, which has good refrigeration effect, but because of its high potential to destroy the ozone layer, according to the relevant provisions of the Montreal Protocol, it is being gradually replaced. R134a (tetrafluoroethane) is also an important halogen refrigerant, which has a lower ozone layer destruction potential, but a higher global warming potential. The working principle of halogen refrigerants is to use their phase change characteristics at different temperatures and pressures to realize heat absorption and release, so as to achieve the effect of refrigeration. They are used in refrigeration systems, and through the coordinated work of components such as compressors, condensers, expansion valves and evaporators, the refrigeration cycle is completed. The application of halogen refrigerants is not limited to air conditioning and refrigerators, but also widely used in industrial refrigeration, commercial refrigeration equipment and automobile air conditioning systems, etc. However, due to its potential harm to the environment, many countries and regions are working to reduce the use of halogen refrigerants and promote more environmentally friendly alternatives.

[0039] In the following, the embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0040] Embodiment 1

[0041] In one embodiment of the present application, a multi-channel refrigerant leakage detector is provided, which can accurately detect the leakage of multiple refrigerants without the need to replace the sensor. The following will be described in detail with reference to the drawings. Figs. 1-3 The multi-channel refrigerant leakage detector of the present application is described in detail, including:

[0042] The gas absorption chamber 6 and the infrared blackbody light source 2 and the multi-channel infrared detector 11 respectively arranged at both ends of the gas absorption chamber 6, the multi-channel infrared detector 11 is a four-channel infrared detector, and the four channels are respectively a reference channel, a carbon dioxide detection channel, a carbon hydrogen refrigerant detection channel and a halogen refrigerant detection channel;

[0043] Among them, the filter corresponding to the reference channel is a filter with a center wavelength of 3.95μm and a bandwidth of 91nm; the filter corresponding to the carbon dioxide detection channel is a filter with a center wavelength of 4.26μm and a bandwidth of 180nm; the filter corresponding to the carbon hydrogen refrigerant detection channel is a filter with a center wavelength of 3.4μm and a bandwidth of 120nm; and the filter corresponding to the halogen refrigerant detection channel is a filter with a center wavelength of 8-14μm.

[0044] In some other embodiments, the multi-channel infrared detector 11 can also be a three-channel infrared detector, which can include a reference channel and any two of the above detection channels.

[0045] It should be noted that the center wavelength and bandwidth parameters of each filter can be adjusted before delivery according to the detection accuracy and the center wavelength of the expected detected refrigerant.

[0046] It should be noted that the filter with a center wavelength of 3.4μm and a bandwidth of 120nm used in the carbon hydrogen refrigerant detection channel in this embodiment can accurately detect R290 refrigerant and R600A refrigerant, because the center wavelengths of R290 and R600A are both 3.4μm.

[0047] It can be understood that a gas pump can also be arranged between the gas inlet and the gas outlet of the multi-channel refrigerant leakage detector to suck the gas to be detected into the absorption chamber.

[0048] The control unit 100 is connected with the infrared blackbody light source 2 and the multi-channel infrared detector 11, and is used to generate a detection result according to the detection signal of the multi-channel infrared detector 11.

[0049] In the embodiment, the gas absorption chamber 6 is provided with a front cover 15 and a rear cover 14 at two ends respectively, the first PCB board 1 is arranged on the front cover 15, the infrared blackbody light source 2 is arranged on the first PCB board 1, the second PCB board 12 is arranged on the rear cover 14, the multi-channel infrared detector 11 is arranged on the second PCB board 12, the upper part of the gas absorption chamber 6 is provided with the third PCB board 5, the control unit 100 is arranged on the third PCB board 5, and the front cover 15 and the rear cover 14 are fixed by the screw 13.

[0050] It can be understood that the control unit 100 determines the concentration of the to-be-detected gas according to the detection signals of the detection channel and the detection signals of the reference channel selected by the multi-channel infrared detector 11, and the principle is the Beer-Lambert law, which will not be repeated here.

[0051] It can be understood that the control unit 100 can also determine the point position of the leakage only according to the detection signal change of the detection channel selected by the multi-channel infrared detector 11 at different detection point positions, without relying on the reference channel to generate a specific concentration value, and only qualitative detection is performed.

[0052] In the embodiment, the multi-channel infrared detector 11 and the control unit 100 are further provided with:

[0053] The switch 102 is connected with the multi-channel infrared detector 11 and the control unit 100, and is used for selecting the channel of the multi-channel infrared detector 11 outputting the detection signal;

[0054] The filter amplification circuit 103 is connected with the switch 102, and is used for filtering and amplifying the detection signal and then outputting to the control unit 100.

[0055] In the embodiment, the gas absorption chamber 6 is wrapped by the first shielding cover 4 and the second shielding cover 8.

[0056] In the embodiment, the top foam 9 is arranged between the gas absorption chamber 6 and the first shielding cover 4, the side foam 3 is arranged between the gas absorption chamber 6 and the infrared blackbody light source 2, the bottom foam 7 is arranged between the gas absorption chamber 6 and the second shielding cover 8, and the sealing ring 10 is further arranged between the gas absorption chamber 6 and the multi-channel infrared detector 11.

[0057] In the embodiment, the communication unit 105, that is, the Bluetooth module, is further arranged, the Bluetooth module is connected with the control unit 100, and is used for transmitting the detection result through Bluetooth.

[0058] It can be understood that the Bluetooth module is connected with the mobile terminal APP, which not only prepares for subsequent product upgrading, but also saves the detection data when the user uses, so that the product is more intelligent and convenient.

[0059] In some other embodiments, the communication unit 105 can also use other wired or wireless communication modules to transmit the detection results to other terminals for users to view the detection results.

[0060] In the present embodiment, an acceleration sensor 107 is also provided, which is connected with the control unit 100, for detecting the acceleration of the refrigerant leakage detector, judging the abnormal operation of the detection gesture in real time, determining the validity of the detection signal, reducing the risk of false alarm, and realizing more accurate and intelligent detection. According to the requirements of ergonomics and instrument operation, the normal acceleration is 0.5-2m / s 2 When the acceleration is greater than 3.5m / s 2 There is a certain probability of false alarm, so when the acceleration greater than 3.5m / s 2 is detected, the detection signal is not considered valid, and no measurement result is generated.

[0061] In the present embodiment, by adjusting the emission angle of the infrared blackbody light source 2 and the distance from the gas absorption chamber 6, at least 80% of the infrared light emitted by the infrared blackbody light source 2 enters the gas absorption chamber 6, and at least 80% of the infrared light after the gas absorption chamber 6 is irradiated on the infrared detector 11, so as to ensure the detection accuracy.

[0062] It can be understood that the multi-channel refrigerant leakage detector is also provided with a gas inlet, a gas pump, a gas outlet and other conventional structures for absorbing and discharging the gas to be measured, which will not be described here.

[0063] In the present embodiment, the infrared blackbody light source 2 is configured to be driven by a constant power driving circuit 106, referring to Fig. 3 , Fig. 3 The constant power driving circuit of the infrared blackbody light source is shown in the structure diagram, as shown in the figure, which includes:

[0064] The DC-DC chip U2, model FP6298, includes EN end, PGND end, OC end, VCC end, LX end, NC end, FB end and GND end, wherein the PGND end (input power ground) is connected with the power node VBAT through the seventh capacitor C7; the PGND end (input power ground) is also connected with the GND node; the OC end (overcurrent protection end) is connected with the GND node through the tenth resistor R10; the VCC end is connected with the power node VBAT; the EN end (enable end) is connected with the power node VBAT and is controlled by the control unit; the LX end (switch MOS end) is connected with the positive electrode of the first diode D1, the negative electrode of the first diode D1 is connected with the FB end (feedback input end) through the third capacitor C3; the NC end is suspended; the FB end is grounded through the sampling resistor R2; the GND end (output ground end) is connected with the GND node.

[0065] A first capacitor C1 is arranged between the power supply node VBAT and the GND node.

[0066] A fourth capacitor C4 is arranged in parallel across the seventh capacitor C7.

[0067] A first inductor L1 is arranged between the power supply node VBAT and the anode of the first diode D1.

[0068] A monitoring chip U1, model MAX421, comprises a GND terminal, an IN terminal, two NC terminals, a VCC terminal, a POUT terminal, an RS- terminal and an RS+ terminal; the GND terminal is connected to the GND node; the VCC terminal is connected to the power supply node VBAT; a second capacitor C2 is further arranged between the GND terminal and the VCC terminal; the IN terminal is connected to the GND node through a ninth capacitor C9; the POUT terminal is connected to the FB terminal of the DC-DC chip through a first resistor R1; the RS- terminal is connected to the GND node through an eleventh resistor R11 and a ninth resistor R9; the RS+ terminal is connected to the cathode of the first diode D1.

[0069] A thirty-fifth resistor R35 has its two ends connected to the cathode of the first diode D1 and a light source voltage node P_5V respectively; the light source voltage node P_5V is further connected to the RS- terminal; the fifth capacitor C5 and the sixth capacitor C6 are further arranged in parallel between the light source voltage node P_5V and the GND node.

[0070] The working principle of the constant-power driving circuit 106 is as follows:

[0071] The control unit enables the EN pin of the DC-DC chip; when the EN is high, the sixth resistor R6 and the twelfth capacitor C12 are filtered by resistance and capacitance, so that the signal is smoother, and the output voltage is also correspondingly smoothed. At the same time, through the sampling resistor R2, the current flowing through the infrared blackbody light source 2 is detected; if the current is too large, feedback adjustment is performed through the monitoring chip MAX4210, the Upout becomes larger, the voltage of the FB pin of the DC-DC chip is larger, and the output voltage of the DC-DC chip is reduced. If the sampling resistor R2 detects that the current is too small, the voltage of the Upout of the monitoring chip is reduced, the voltage of the FB pin of the DC-DC chip is reduced, and the DC-DC chip outputs a larger voltage to maintain the power of the light source. In addition, the control unit 100 detects the Upout voltage signal; if the signal is abnormal, the single-chip microcomputer switches the enablement end EN pin, and the DC-DC chip stops power supply to the light source, thereby protecting the infrared blackbody light source 2.

[0072] In the embodiment, the constant-power driving circuit 106 adds soft start, avoids the oscillation of the power supply voltage caused by the power-on moment, and further adds RC resistance and capacitance filtering to prevent the peak current from damaging the infrared blackbody light source 2.

[0073] In some other embodiments, the constant power drive circuit 106 can also be other constant power drive circuits provided with RC blocking capacitor filtering and soft start to ensure stable operation of the infrared blackbody light source.

[0074] It can be understood that the multi-channel refrigerant leakage detector according to the embodiments of the present application can detect the point where the gas leakage may exist by detecting the gas concentration, and the greater the detected gas concentration value, the closer to the point where the gas leakage may exist.

[0075] Exemplarily, one working process of the embodiments of the present application is as follows:

[0076] If it is necessary to detect each point where the carbon dioxide refrigerant leakage may exist, first, the refrigerant leakage detector is powered on and warmed up for 30 seconds, and the gas pump and the infrared blackbody light source 2 are turned on; the acceleration signal is read in real time; the carbon dioxide detection channel of the multi-channel infrared detector 11 is controlled by the control unit 100, the detection signal of the carbon dioxide detection channel is collected in real time and output to the control unit after being filtered and amplified by the filter amplification circuit; the gas inlet of the refrigerant leakage detector is aligned with each point in turn, and the control unit 100 judges whether each point has carbon dioxide leakage according to the change of the real-time detection signal, and gives the detection result of whether there is leakage.

[0077] Exemplarily, another working process of the embodiments of the present application is as follows:

[0078] When the refrigerant leakage detector is used to detect each point where the carbon dioxide refrigerant leakage may exist, first, the refrigerant leakage detector is powered on and warmed up for 30 seconds, the gas pump is turned on, and the pulse width modulation infrared blackbody light source 2 is turned on; the acceleration signal is read in real time; then the gas inlet of the refrigerant leakage detector is aligned with each point in turn to start detection, when each point is detected, the control unit 100 selects the reference channel and the carbon dioxide detection channel of the multi-channel infrared detector in turn, and the line board analog switch is electronically switched; the detection signal is collected and filtered and amplified by the filter amplification circuit, and then enters the control unit for processing; the control unit generates the quantitative detection result of the point according to the ratio of the detection signal of the selected carbon dioxide channel and the detection signal of the reference channel.

[0079] The above description merely illustrates the application of a part of the embodiments of the present application and the explanation of the principles of the applied technology. It should be understood by those skilled in the art that the disclosed range of the present application is not limited to the technical solutions formed by the specific combinations of the technical features described above, and should also cover other technical solutions formed by any combinations of the technical features described above or their equivalent features without departing from the disclosed concept. For example, the technical solutions formed by replacing the above features with the technical features disclosed in the present application (but not limited to) having similar functions.

[0080] Furthermore, although operations have been depicted in a particular order, this should not be understood as requiring such order nor limiting it to only that order. Multi-tasking and parallel processing can be advantageous in certain circumstances. Likewise, although several specific implementation details have been discussed, these should not be construed as limiting the scope of the application. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination.

[0081] Although the subject matter has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A multi-channel refrigerant leak detector, comprising: include: A gas absorption chamber is provided at both ends, with an infrared blackbody light source and a multi-channel infrared detector respectively. The multi-channel infrared detector includes a reference channel and at least two detection channels. The filters corresponding to the detection channels are configured to detect any one of the following refrigerants: carbon dioxide, hydrocarbon refrigerants, and halogen refrigerants. Each detection channel is suitable for detecting different types of refrigerants. The control unit, connected to the infrared blackbody light source and the multi-channel infrared detector, is used to generate detection results based on the detection signals from the multi-channel infrared detector.

2. The multi-channel refrigerant leak detector of claim 1, wherein, The multi-channel infrared detector is a four-channel infrared detector, which includes a reference channel, a carbon dioxide detection channel, a hydrocarbon refrigerant detection channel, and a halogen refrigerant detection channel. The filter corresponding to the reference channel has a center wavelength of 3.95 μm; the filter corresponding to the carbon dioxide detection channel has a center wavelength of 4.26 μm; the filter corresponding to the hydrocarbon refrigerant detection channel has a center wavelength of 3.4 μm; and the filter corresponding to the halogen refrigerant detection channel has a center wavelength of 8-14 μm.

3. The multi-channel refrigerant leak detector of claim 1, wherein, The gas absorption chamber is provided with a front cover and a rear cover at both ends. A first PCB board is provided on the front cover, and an infrared blackbody light source is provided on the first PCB board. A second PCB board is provided on the rear cover, and a multi-channel infrared detector is provided on the second PCB board. A third PCB board is provided on the upper part of the gas absorption chamber, and a control unit is provided on the third PCB board.

4. The multi-channel refrigerant leak detector of claim 1, wherein, A further connection is provided between the multi-channel infrared detector and the control unit: A switch, connected to the multi-channel infrared detector and the control unit, is used to select the channel through which the multi-channel infrared detector outputs the detection signal; A filtering and amplification circuit, connected to the switch, is used to filter and amplify the detection signal before outputting it to the control unit.

5. The multi-channel refrigerant leak detector of claim 1, wherein, Also includes: An acceleration sensor, connected to the control unit, is used to detect the acceleration of the refrigerant leak detector.

6. The multi-channel refrigerant leak detector of claim 1, wherein, It also includes a Bluetooth module, which is connected to the control unit and is used to transmit the detection results via Bluetooth.

7. The multi-channel refrigerant leak detector of claim 1, wherein, The infrared blackbody light source is configured to be driven by a constant power drive circuit.

8. The multi-channel refrigerant leak detector of claim 7, wherein, The constant power drive circuit includes: The DC-DC chip includes an EN terminal, a PGND terminal, an OC terminal, a VCC terminal, an LX terminal, a NC terminal, an FB terminal, and a GND terminal. The PGND terminal is connected to the power supply node via a seventh capacitor; the PGND terminal is also connected to the GND node; the OC terminal is connected to the GND node via a tenth resistor; the VCC terminal is connected to the power supply node; the EN terminal is connected to the power supply node and is controlled by the control unit; the LX terminal is connected to the anode of the first diode D1, and the cathode of the first diode is connected to the FB terminal via a third capacitor; the NC terminal is left floating; the FB terminal is grounded via a sampling resistor; and the GND terminal is connected to the GND node. The first capacitor is located between the power node and the GND node. The fourth capacitor is connected in parallel across the seventh capacitor; The first inductor is positioned between the power supply node and the positive terminal of the first diode; The monitoring chip comprises a GND terminal, an IN terminal, two NC terminals, a VCC terminal, a POUT terminal, an RS- terminal and an RS+ terminal; the GND terminal is connected with a GND node; the VCC terminal is connected with a power supply node; a second capacitor is further arranged between the GND terminal and the VCC terminal; the IN terminal is connected with the GND node through a ninth capacitor; the POUT terminal is connected with an FB terminal of a DC-DC chip through a first resistor; the RS- terminal is connected with the GND node through an eleventh resistor and a ninth resistor; the RS+ terminal is connected with a cathode of a first diode; A thirty-fifth resistor has its two ends connected with the cathode of the first diode and a light source voltage node respectively; the light source voltage node is further connected with the RS- terminal; a fifth capacitor and a sixth capacitor are further arranged in parallel between the light source voltage node and the GND node.

9. The multi-channel refrigerant leak detector of claim 1, wherein, The gas absorption chamber is wrapped by two shielding covers.

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