R290 refrigerant gas leakage detection method and detection device

Abstract

The present invention discloses a method and device for detecting leakage of R290 refrigerant gas, which include: obtaining status information of a reflective surface in an infrared air chamber of an infrared sensor, the status information including a non-condensed / non-frosted state and a condensed / frosted state; if the reflective surface is in the non-condensed / non-frosted state, using an infrared sensor to detect whether R290 refrigerant gas is present in the infrared air chamber, and outputting a first signal to a controller when R290 refrigerant gas is detected; if the reflective surface is in the condensed / frosted state, using an auxiliary sensor to detect whether R290 refrigerant gas is present, and outputting a second signal to the controller when R290 refrigerant gas is detected, wherein the detection principle of the auxiliary sensor is different from the detection principle of the infrared sensor, and the detection principle adopted by the auxiliary sensor is not affected by condensation / frosting; in this way, effective detection of R290 refrigerant gas can be achieved while ensuring that power consumption is not too high.

Description

Technical Field

[0001] The present invention relates to the technical field of gas detection, and in particular to an R290 refrigerant gas leakage detection method and an R290 refrigerant gas leakage detection device. Background Art

[0002] Refrigerants, essential for thermal comfort control, are widely used in refrigerators, industrial refrigeration, air conditioners, and many other applications. R290 (A3) is a member of a new class of green and environmentally friendly refrigerants, significantly less destructive to the ozone layer than R22. With calls for ozone layer protection growing globally, the development of new refrigerants is of great significance.

[0003] Since R290 refrigerant gas is flammable and explosive, if it leaks during use, the concentration in the local environment may reach combustion proportions, posing a serious threat to life and property. Therefore, it is necessary to monitor the R290 refrigerant gas concentration in the use environment in real time and have an alarm function.

[0004] Thermal conductivity gas sensors are used in refrigerant leak detection due to their small size, high reliability, immunity to condensation and frosting, and fast response time. However, they suffer from poor detection accuracy for R290 refrigerant gas, which has a low explosion limit and a thermal conductivity close to that of air.

[0005] Ultrasonic gas sensing technology uses the principle of measuring the speed of sound during ultrasonic propagation, then measures the average molecular weight of the gas, and then calculates the concentration of the gas to be measured. It has the advantages of small size, low power consumption, fast response time, and long life. However, this detection principle also has the defect of poor detection accuracy for R290 refrigerant gas, which has a low explosion limit and a molecular mass close to the average molecular weight of air.

[0006] NDIR infrared gas sensors, on the other hand, utilize infrared absorption principles to detect gas concentrations, offering high selectivity. By selecting different filters, they can detect a wide range of gases, adapting to diverse application requirements. Their high sensitivity allows them to detect even extremely low concentrations of gas. Furthermore, NDIR sensors offer fast response times and long lifespans, making them capable of detecting R290 refrigerant gas. For example, as described in patent CN221549928U, the applicant discovered that when used in air conditioning applications, NDIR infrared gas sensors are susceptible to condensation and frosting caused by rapid temperature changes in some refrigeration systems. Therefore, the sensors require heating and insulation functions to prevent condensation and frosting, but this increases the sensor's size and power consumption, limiting its application.

[0007] In addition, MOX sensors, electrochemical sensors and thermocatalytic sensors can also detect R290 refrigerant gas. However, the sensitivity of MOX sensors decreases as their usage time increases, and electrochemical sensors and thermocatalytic sensors have a short service life. Summary of the Invention

[0008] The main purpose of the present invention is to provide an R290 refrigerant gas leakage detection method and an R290 refrigerant gas leakage detection device with improved detection reliability.

[0009] To achieve the above object, the present invention proposes a method for detecting R290 refrigerant gas leakage, comprising the following steps:

[0010] Step S1, obtaining state information of a reflective surface in an infrared chamber of an infrared sensor, wherein the state information includes a non-condensed / non-frosted state and a condensed / frosted state;

[0011] Step S2: If the reflecting surface is in the non-condensing / non-frosting state, the infrared sensor is used to detect in real time whether R290 refrigerant gas is present in its infrared air chamber, and a first signal is output to the controller when the R290 refrigerant gas is detected; if the reflecting surface is in the condensing / frosting state, the auxiliary sensor is used to detect in real time whether R290 refrigerant gas is present, and a second signal is output to the controller when the R290 refrigerant gas is detected; wherein the detection principle of the auxiliary sensor is different from the detection principle of the infrared sensor, and the detection principle adopted by the auxiliary sensor is not affected by condensation / frosting.

[0012] The present invention also provides an R290 refrigerant gas leakage detection device, which is applicable to the R290 refrigerant gas leakage detection method. The R290 refrigerant gas leakage detection device includes:

[0013] The housing is provided with an air inlet for allowing the gas to be measured to enter the housing;

[0014] An infrared sensor is disposed in the housing, and its infrared air chamber is connected to the air inlet to allow the gas to be tested to pass through for detection;

[0015] an auxiliary sensor, disposed in the housing and in communication with the air inlet, for detecting whether R290 refrigerant gas is present in the gas to be tested, wherein the detection principle of the auxiliary sensor is different from that of the infrared sensor, and the detection principle adopted by the auxiliary sensor is not affected by condensation / frosting; and

[0016] The controller is electrically connected to the infrared sensor and the auxiliary sensor, and is used to obtain status information of the reflective surface in the infrared chamber and receive the first signal of the infrared sensor or the second signal of the auxiliary sensor according to the status information.

[0017] In the technical solution of the present invention, based on the status information of the reflecting surface in the infrared gas chamber of the infrared sensor, when the reflecting surface is in a non-condensing / non-frosting state, the infrared sensor is selected to detect in real time whether there is R290 refrigerant gas. When the reflecting surface is in a condensing / frosting state, an auxiliary sensor whose detection principle is different from that of the infrared sensor and whose detection principle is not affected by condensation / frosting can be used to detect in real time whether there is R290 refrigerant gas. In this way, the infrared sensor and the auxiliary sensor are combined to detect whether R290 refrigerant gas leakage occurs, that is, when the reflecting surface is in the condensing / frosting state and affects the measurement of the infrared sensor, the auxiliary sensor is used for detection and outputs a second signal to the controller, thereby solving the problem that the infrared sensor is affected by condensation / frosting caused by rapid changes in temperature and humidity in the refrigeration system, and the problem of large size and high power consumption caused by adding a heating circuit to prevent condensation and frosting. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 the structures shown in these drawings without paying any creative work.

[0019] Figure 1 Flowchart of the R290 refrigerant gas leakage detection method provided by the present invention;

[0020] Figure 2 This is a flowchart of an embodiment of step S111;

[0021] Figure 3 is a flowchart of another embodiment of step S111;

[0022] Figure 4 This is a schematic structural diagram of an embodiment of the R290 refrigerant gas leakage detection device provided by the present invention (the auxiliary device is a thermal conductivity sensor);

[0023] Figure 5 A schematic diagram of another embodiment of the R290 refrigerant gas leakage detection device provided by the present invention (the auxiliary device is an acoustic resonance ultrasonic sensor)

[0024] Description of Figure Numbers:

[0025] 100. R290 refrigerant gas leakage detection device;

[0026] 1. Shell, 11. Upper cover, 111. Air inlet; 12. Lower cover;

[0027] 2. Infrared sensor;

[0028] 3. Auxiliary sensor;

[0029] 4. Waterproof and breathable membrane;

[0030] 5. Electromagnetic shielding cover.

[0031] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0033] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0034] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] NDIR infrared gas sensors, on the other hand, utilize infrared radiation to detect gas concentrations, offering a high degree of selectivity. By selecting different filters, they can detect a variety of gases, adapting to diverse application requirements. Their high sensitivity allows them to detect even extremely low concentrations of gas. Furthermore, NDIR sensors offer fast response times and long lifespans, making them capable of detecting R290 refrigerant gas. For example, as described in patent CN221549928U, the applicant discovered that when used in air conditioning applications, NDIR infrared gas sensors are susceptible to condensation and frosting caused by rapid temperature changes in some refrigeration systems. Therefore, the sensors require heating and insulation functions to prevent condensation and frosting. However, this increases the sensor's size and power consumption, limiting its application.

[0036] In view of this, the present invention provides a method for detecting leakage of R290 refrigerant gas. Figures 1 to 3 This is a flow chart of the R290 refrigerant gas leakage detection method provided by the present invention.

[0037] See also Figure 1 , the R290 refrigerant gas leakage detection method comprises the following steps:

[0038] Step S1: Acquire state information of a reflective surface in an infrared chamber of an infrared sensor, wherein the state information includes a non-condensed / non-frosted state and a condensed / frosted state.

[0039] Step S2: If the reflecting surface is in the non-condensing / non-frosting state, the infrared sensor is used to detect in real time whether R290 refrigerant gas is present in its infrared gas chamber, and a first signal is output to the controller when the R290 refrigerant gas is detected. If the reflecting surface is in the condensing / frosting state, an auxiliary sensor is used to detect in real time whether R290 refrigerant gas is present, and a second signal is output to the controller when the R290 refrigerant gas is detected, wherein the detection principle of the auxiliary sensor is different from the detection principle of the infrared sensor, and the detection principle adopted by the auxiliary sensor is not affected by condensation / frosting.

[0040] In the technical solution of the present invention, based on the status information of the reflecting surface in the infrared gas chamber of the infrared sensor, when the reflecting surface is in a non-condensing / non-frosting state, the infrared sensor is selected to detect in real time whether there is R290 refrigerant gas. When the reflecting surface is in a condensing / frosting state, an auxiliary sensor whose detection principle is different from that of the infrared sensor and whose detection principle is not affected by condensation / frosting can be used to detect in real time whether there is R290 refrigerant gas. In this way, the infrared sensor and the auxiliary sensor are combined to detect whether R290 refrigerant gas leakage occurs, that is, when the reflecting surface is in the condensing / frosting state and affects the measurement of the infrared sensor, the auxiliary sensor is used for detection and outputs a second signal to the controller, thereby solving the problem that the infrared sensor is affected by condensation / frosting caused by rapid changes in temperature and humidity in the refrigeration system, and the problem of large size and high power consumption caused by adding a heating circuit to prevent condensation and frosting.

[0041] Furthermore, the auxiliary sensor is a thermal conductivity sensor, an acoustic resonance ultrasound sensor, a photoacoustic spectroscopy sensor, a MOX sensor, an electrochemical sensor or a thermocatalytic sensor.

[0042] It should be noted that because the practicality of the MOX sensor, electrochemical sensor, and thermocatalytic sensor is limited by their usage time, when the reflective surface is in the condensation / frosting state, the MOX sensor, electrochemical sensor, or thermocatalytic sensor is in the on state, and when the reflective surface is in the non-condensation / frosting state, the MOX sensor, electrochemical sensor, or thermocatalytic sensor is in the off state. In other words, the MOX sensor, electrochemical sensor, and thermocatalytic sensor are only activated and used when the reflective surface is in the condensation / frosting state.

[0043] The thermal conductivity sensor, acoustic resonance ultrasonic sensor, and photoacoustic spectroscopy sensor themselves have a long service life, and their sensitivity is less affected by the use time. Therefore, when the auxiliary sensor is one of the thermal conductivity sensor, acoustic resonance ultrasonic sensor, and photoacoustic spectroscopy sensor, the auxiliary sensor can be used intermittently, that is, when the reflecting surface is in the non-condensing / non-frosting state, the infrared sensor is used for detection, and the auxiliary sensor is in the off state; when the reflecting surface is in the condensing / frosting state, the auxiliary sensor is in the on state for detection; of course, the auxiliary sensor can also start detection at the same time as the infrared sensor, which can be used to verify the detection results of the infrared sensor.

[0044] In some embodiments of the present invention, step S2 specifically includes:

[0045] Step S21', starting the infrared sensor and the auxiliary sensor to detect in real time whether R290 refrigerant gas is present; if the reflecting surface is in the non-condensing / non-frosting state, the infrared sensor outputs the first signal to the controller when detecting the R290 refrigerant gas; if the reflecting surface is in the condensing / frosting state, the auxiliary sensor outputs the second signal to the controller when detecting the R290 refrigerant gas.

[0046] In this way, the detection result of the infrared sensor can be synchronously verified in combination with the auxiliary sensor. That is, when the infrared sensor detects that the R290 refrigerant gas concentration value reaches the detection accuracy of the auxiliary sensor, the auxiliary sensor is used to verify whether R290 refrigerant gas exists, and then the result is output as needed. It should be noted that the output result at this time can be flexibly configured in the actual product. For example, when the auxiliary sensor detects R290 refrigerant gas, the algorithm remains unchanged. When the auxiliary sensor does not detect refrigerant gas, the data can be recorded for subsequent analysis, or the output of the first signal can be stopped.

[0047] In some other embodiments of the present invention, step S2 specifically includes:

[0048] Step S21'': If the reflecting surface is in the non-condensing / non-frosting state, the infrared sensor is used to detect in real time whether R290 refrigerant gas is present in its infrared gas chamber, and the first signal is output to the controller when the R290 refrigerant gas is detected. After the R290 refrigerant gas concentration value detected by the infrared sensor reaches the auxiliary sensor detection accuracy, the auxiliary sensor is started to detect in real time whether R290 refrigerant gas is present, and the second detected signal is output to the controller. If the reflecting surface is in the condensing / frosting state, the auxiliary sensor is used to detect in real time whether R290 refrigerant gas is present, and the second signal is output to the controller when R290 refrigerant gas is detected.

[0049] In this way, not only the startup time of the auxiliary sensor can be reduced, but also the detection result of the infrared sensor can be synchronously verified in combination with the auxiliary sensor, which will not be elaborated here.

[0050] Specifically, the step S1 includes:

[0051] Step S11: Acquire status information of the reflective surface according to the infrared sensor and / or the temperature and humidity sensor.

[0052] That is, in the present invention, the state information of the reflecting surface can be obtained according to either the infrared sensor or the temperature and humidity sensor, or by combining the infrared sensor and the temperature and humidity sensor.

[0053] Furthermore, in the first embodiment of the present invention, the infrared sensor is a dual-channel infrared sensor having a first detector corresponding to a detection channel and a second detector corresponding to a reference channel. The filter provided in the detection channel can filter light of a wavelength band absorbed by the R290 refrigerant gas, and the filter provided in the reference channel can filter light of a wavelength band that is not absorbed by any gas that has or may be generated in the application scenario of the detection device of this embodiment. The first signal change rate x1 of the light signal received by the first detector at least reflects the change of the R290 refrigerant gas, and the second signal change rate x2 of the light signal received by the second detector at least reflects the change of the environment. In this way, the state information of the reflective surface in the infrared air chamber can be directly obtained through the infrared sensor.

[0054] The step S11 specifically includes:

[0055] Step S111: Obtain state information of the reflecting surface at least according to the second signal change rate x2.

[0056] Furthermore, the state information of the reflecting surface may be further obtained through the change values of the first signal change rate x1 and the second signal change rate x2 and their differences.

[0057] See also Figure 2 , the step S111 specifically includes:

[0058] Step S1111: Obtain the first signal change rate x1 and the second signal change rate x2.

[0059] Step S1112: within the first preset time, if the light signal received by the first detector and the light signal received by the second detector both decrease, and x1<λ1, x2<λ1 and |x1-x2|<λ2, it is determined that a temperature change occurs in the infrared chamber and the reflecting surface is in the non-condensing / non-frosting state; within the first preset time, if the light signal received by the first detector and the light signal received by the second detector both decrease, and x1<λ1, x2<λ1 and |x1-x2|>λ2, it is determined that a temperature change occurs in the infrared chamber and the reflecting surface is in the non-condensing / non-frosting state, and R290 refrigerant gas exists; if within the second preset time, the first If the optical signal received by the detector and the optical signal received by the second detector both decrease and |x1-x2|<λ2, and the rate of change x2 of the second signal increases and x2>λ3 within the third preset time, it is determined that the reflecting surface is in the condensation / frosting state; if the optical signal received by the first detector and the optical signal received by the second detector both decrease and |x1-x2|<λ2 within the second preset time, and change to x1>x2>λ3 within the third preset time, it is determined that the reflecting surface is in the condensation / frosting state and R290 refrigerant gas is suspected to be present; wherein λ1 is the first preset threshold, λ2 is the second preset threshold, λ3 is the third preset threshold, and λ2<λ1<λ3.

[0060] It should be noted that the light signal received by the first detector and the light signal received by the second detector both decrease, and x1<λ1, x2<λ1 and |x1-x2|<λ2, that is, the light signal received by the first detector and the light signal received by the second detector both decrease, and the change rates of the two signals are small and close (that is, basically the same). At this time, it can be judged that the temperature changes in the infrared chamber and the reflecting surface is in the non-condensed / non-frosted state.

[0061] The optical signal received by the first detector and the optical signal received by the second detector both decrease, and x1<λ1, x2<λ1 and |x1-x2|>λ2, that is, the optical signal received by the first detector and the optical signal received by the second detector both decrease, and the change rates of the two signals differ greatly. At this time, it can be determined that a temperature change occurs in the infrared chamber and the reflecting surface is in the non-condensed / non-frosted state. At the same time, it also indicates that the infrared sensor detects R290 refrigerant gas, that is, R290 refrigerant gas is present.

[0062] Within the second preset time, the optical signal received by the first detector and the optical signal received by the second detector both decrease and |x1-x2|<λ2, and within the third preset time, the second signal change rate x2 increases and x2>λ3. That is, the optical signal received by the first detector and the optical signal received by the second detector both decrease, and the two signal change rates are close (that is, basically the same) within the second preset time, but within the third preset time, the second signal change rate x2 suddenly increases and is greater than the third preset threshold λ3. At this time, it can be determined that the reflecting surface is in the condensation / frosting state.

[0063] Within the second preset time, the optical signal received by the first detector and the optical signal received by the second detector both decrease and |x1-x2|<λ2, and within the third preset time, they change to x1>x2>λ3, that is, the optical signal received by the first detector and the optical signal received by the second detector both decrease, and within the second preset time, the change rates of the two signals are close (that is, basically the same), but within the third preset time, the first signal change rate x1 and the second signal change rate x2 both suddenly increase to be greater than λ3, and the first signal change rate x1 is greater than the second signal change rate x2. At this time, it can be determined that the reflecting surface is in the condensation / frosting state. At the same time, it also indicates that the infrared sensor may have detected R290 refrigerant gas, that is, R290 refrigerant gas is suspected to be present.

[0064] In addition, when the light signal received by the first detector decreases, while the light signal received by the second detector remains substantially unchanged, it indicates that the infrared sensor may have detected R290 refrigerant gas.

[0065] Specifically, in another embodiment of the present invention, a temperature sensor is further provided;

[0066] The step S111 specifically includes:

[0067] Step S1111′, obtaining the first signal change rate x1 and the second signal change rate x2;

[0068] Step S1112′: within a first preset time, if the temperature change detected by the temperature sensor is greater than or equal to a fourth preset threshold, and if the light signal received by the second detector decreases and x2<λ1, then it is determined that a temperature change occurs in the infrared chamber and the reflecting surface is in the non-condensing / non-frosting state; if the light signal received by the second detector decreases within a second preset time, and within a third preset time, the rate of change x2 of the second signal increases and x2>λ3, then it is determined that the reflecting surface is in the condensing / frosting state;

[0069] If the temperature change detected by the temperature sensor is less than a fourth preset threshold, it is determined that the reflective surface is in the non-condensing / non-frosting state.

[0070] It should be noted that the first preset time can be set to 30s, 60s, 90s, etc., the second preset time and the third preset time are within the first preset time, and the first preset time is greater than or equal to the sum of the second preset time and the third preset time.

[0071] Specifically, in the second embodiment of the present invention, step S11 specifically includes:

[0072] Step S111 ′: using the temperature and humidity sensor to obtain the ambient temperature and humidity.

[0073] Step S112': within the first preset time, if the ambient temperature rises from below zero to zero degrees Celsius or above, and the air has a certain humidity, it is determined that the reflective surface is in a frosted state; if the ambient temperature rises from above zero degrees Celsius and the ambient humidity is greater than or equal to the condensation humidity critical point at this temperature, it is determined that the reflective surface is in a condensed state.

[0074] It should be noted that, at a certain temperature, the humidity in the air reaches a preset value and enters a condensation state, and the preset value is the condensation humidity critical point.

[0075] In addition, when the status information of the reflective surface is obtained according to the temperature and humidity sensor, the infrared sensor may be used for verification to confirm the actual status of the reflective surface.

[0076] Therefore, in the third embodiment of the present invention, the infrared sensor is a dual-channel infrared sensor having a first detector corresponding to a detection channel and a second detector corresponding to a reference channel; the status information also includes a suspected condensation / frosting state; and step S11 specifically includes:

[0077] Step S111'', judging the state of the reflecting surface according to the ambient temperature and humidity detection results of the temperature and humidity sensor to obtain a first state judgment result, and judging the state of the reflecting surface according to at least the second signal change rate x2 of the light signal received by the second detector to obtain a second state judgment result.

[0078] It should be noted that in this step, the specific steps for obtaining the first state determination result based on the temperature and humidity sensor are substantially the same as steps S111' and S112' described above, and therefore are not further described. Similarly, in this step, the specific steps for obtaining the second state determination result based on the first signal change rate x1 of the optical signal received by the first detector and the second signal change rate x2 of the optical signal received by the second detector are substantially the same as steps S1111 and S1112 described above, and therefore are not further described.

[0079] Step S112'': if both the first state judgment result and the second state judgment result indicate that the reflective surface is in the condensation / frosting state, confirming that the reflective surface is in the condensation / frosting state;

[0080] If the first state judgment result is a non-condensation / non-frosting state, and the second state judgment result is a condensation / frosting state, confirming that the reflective surface is in the suspected condensation / frosting state;

[0081] If the first state judgment result is that the reflective surface is in the condensation / frosting state, and the second state judgment result is that the reflective surface is not in the condensation / frosting state, confirming that the reflective surface is in the suspected condensation / frosting state;

[0082] If both the first state judgment result and the second state judgment result are that the infrared chamber is not in the condensation / frosting state, it is confirmed that the infrared chamber is in the non-condensation / non-frosting state.

[0083] In this way, by combining the first state judgment result and the second state judgment result for comprehensive judgment, more accurate state information of the reflecting surface can be obtained, thereby improving the accuracy of the R290 refrigerant gas leakage detection result.

[0084] Furthermore, the step S2 specifically includes:

[0085] Step S21: If the reflecting surface is in the non-condensing / non-frosting state, the infrared sensor is used to detect in real time whether there is R290 refrigerant gas in its infrared gas chamber, and the first signal is output to the controller when the R290 refrigerant gas is detected; if the reflecting surface is in the confirmed condensation / frosting state, the auxiliary sensor is used to detect in real time whether there is R290 refrigerant gas, and the second signal is output to the controller when the R290 refrigerant gas is detected; if the reflecting surface is in the suspected condensation / frosting state, when the infrared sensor does not detect R290 refrigerant gas, no signal is output; when the infrared sensor detects R290 refrigerant gas and the auxiliary sensor does not detect R290 refrigerant gas, no signal is output; when the infrared sensor detects R290 refrigerant gas and the auxiliary sensor detects R290 refrigerant gas, the second signal is output to the controller.

[0086] That is, in the third embodiment of the present invention, when it is determined that the reflecting surface is in the non-condensed / non-frosted state, the first signal obtained by detection by the infrared sensor is output to the controller, and when it is determined that the reflecting surface is in the condensed / frosted state, the second signal obtained by detection by the auxiliary sensor is output to the controller, and when the reflecting surface is in the suspected condensed / frosted state, the infrared sensor and the auxiliary sensor both perform real-time detection, but when the infrared sensor or the auxiliary sensor does not detect the R290 refrigerant gas, no signal is output, and when both the infrared sensor and the auxiliary sensor detect the R290 refrigerant gas, the second signal is output.

[0087] The present invention further provides an R290 refrigerant gas leakage detection device 100, which is applicable to the R290 refrigerant gas leakage detection method described above.

[0088] For details, please refer to Figure 4 and Figure 5The R290 refrigerant gas leakage detection device 100 includes a shell 1, an infrared sensor 2, an auxiliary sensor 3 and a controller. The shell 1 is provided with an air inlet 111 for the gas to be tested to pass into the shell 1; the infrared sensor 2 is arranged in the shell 1, and its infrared air chamber is communicated with the air inlet 111 for the gas to be tested to pass into and be detected; the auxiliary sensor 3 is arranged in the shell 1 and is communicated with the air inlet 111 for detecting whether R290 refrigerant gas exists in the gas to be tested. The detection principle of the auxiliary sensor 3 is different from that of the infrared sensor 2, and the auxiliary sensor 3 is not affected by condensation / frost; the controller is electrically connected to the infrared sensor 2 and the auxiliary sensor 3, and is used to obtain status information of the reflective surface in the infrared air chamber, and receive the first signal of the infrared sensor 2 or the second signal of the auxiliary sensor 3 according to the status information.

[0089] In this way, by integrating the infrared sensor 2 and the auxiliary sensor 3 to detect the leakage of R290 refrigerant gas, specifically, using the infrared sensor 2 as the main sensor and the auxiliary sensor 3 as the auxiliary sensor for detection, not only can the problem of infrared sensor 2 being affected by condensation and frosting caused by rapid changes in temperature and humidity in the refrigeration system, and the problem of adding a heating circuit to prevent condensation and frosting, which is large in size and high in power consumption, be solved, but the probability of the reflective surface being in the condensation / frosting state is also low, and when in the condensation / frosting state, the auxiliary sensor 3 can still detect the R290 refrigerant gas and output a signal value. The R290 refrigerant gas leakage detection device 100 provided by the present invention has the characteristics of low power consumption, long life, resistance to condensation / frosting interference, and high detection accuracy.

[0090] It should be noted that, in some embodiments of the present invention, the infrared sensor 2 is not only used to detect whether there is R290 refrigerant gas in the gas to be tested, but also can be used to detect the status information of the reflective surface in the infrared chamber.

[0091] It should also be noted that, in the present invention, the relative positions of the auxiliary sensor 3 and the infrared sensor 2 are not limited, and the auxiliary sensor 3 may be arranged outside the infrared sensor 2 (such as Figure 4 and Figure 5 As shown), at this time, the auxiliary sensor 3 detects the gas to be measured that is passed into the shell 1, or the auxiliary sensor 3 can be arranged in the infrared sensor 2. At this time, the auxiliary sensor 3 detects the gas to be measured that is passed into the infrared gas chamber.

[0092] It should also be noted that, in one embodiment of the present invention, a vent hole is provided on the housing 1 , an air intake grille is provided at the vent hole, and the air inlet 111 is formed on the air intake grille.

[0093] Furthermore, the controller executes the steps of the R290 refrigerant gas leakage detection method described above.

[0094] Specifically, the auxiliary sensor 3 is a thermal conductivity sensor (such as Figure 4 As shown), acoustic resonance ultrasonic sensor (as Figure 5 shown), MOX sensor, electrochemical sensor or thermocatalytic sensor.

[0095] Specifically, the R290 refrigerant gas leak detection device 100 further includes a temperature and humidity sensor disposed within the housing 1 for detecting ambient temperature and humidity. The controller is electrically connected to the temperature and humidity sensor. Thus, the temperature and humidity sensor detects ambient temperature and humidity, and the relationship between ambient temperature and humidity and condensation / frosting is combined to obtain information about the reflective surface's status.

[0096] More specifically, the infrared sensor 2 and the temperature and humidity sensor may be combined to obtain the status information of the reflecting surface to improve accuracy.

[0097] For details, please refer to Figure 4 and Figure 5 The shell 1 includes an upper cover 11 and a lower cover 12, and the upper cover 11 and the lower cover 12 are buckled together to form a accommodating cavity. The air inlet 111 is provided at the upper cover 11 or the lower cover 12; the R290 refrigerant gas leakage detection device 100 also includes a waterproof and breathable membrane 4 and at least one electromagnetic shielding cover 5, and the waterproof and breathable membrane 4 is provided at the air inlet 111; the electromagnetic shielding cover 5 is provided in the accommodating cavity, and the infrared sensor 2 and / or the auxiliary sensor 3 are housed therein; the controller is provided in the accommodating cavity.

[0098] In this way, the upper cover 11 and the lower cover 12 are snap-fitted together, making installation and removal easy. Furthermore, by providing the waterproof and breathable membrane 4 at the air inlet 111, water can be prevented from entering the housing 1, thereby damaging the electronic components within the housing 1 and even causing safety accidents. Furthermore, by providing the electromagnetic shielding cover 5, external electromagnetic interference can be effectively shielded, improving the anti-interference performance of the infrared sensor 2 and the auxiliary sensor 3.

[0099] It should be noted that, in the present invention, one electromagnetic shielding cover 5 can be provided, and the infrared sensor 2 and the auxiliary sensor 3 are both provided in the electromagnetic shielding cover 5. Of course, two electromagnetic shielding covers 5 can also be provided, and the infrared sensor 2 is provided in one of the two electromagnetic shielding covers 5, and the auxiliary sensor 3 is provided in the other.

[0100] Specifically, in one embodiment of the present invention, the first signal and the second signal each include not only a concentration signal but also an alarm signal. In this regard, the controller is further configured to electrically connect to an external alarm device to control the operation of the external alarm device upon receiving the first signal or the second signal.

[0101] Of course, the controller may also be electrically connected to an external terminal to transmit the received first signal or the second signal to the external terminal.

[0102] 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 transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for detecting leakage of R290 refrigerant gas, characterized in that: The R290 refrigerant gas leakage detection method comprises the following steps: Step S1, obtaining state information of a reflective surface in an infrared chamber of an infrared sensor, wherein the state information includes a non-condensed / non-frosted state and a condensed / frosted state; Step S2: If the reflecting surface is in the non-condensing / non-frosting state, the infrared sensor is used to detect in real time whether R290 refrigerant gas is present in its infrared air chamber, and a first signal is output to the controller when the R290 refrigerant gas is detected; if the reflecting surface is in the condensing / frosting state, the auxiliary sensor is used to detect in real time whether R290 refrigerant gas is present, and a second signal is output to the controller when the R290 refrigerant gas is detected; wherein the detection principle of the auxiliary sensor is different from the detection principle of the infrared sensor, and the detection principle adopted by the auxiliary sensor is not affected by condensation / frosting.

2. The R290 refrigerant gas leakage detection method according to claim 1, wherein: The step S1 specifically includes: Step S11: Acquire status information of the reflective surface according to the infrared sensor and / or the temperature and humidity sensor.

3. The R290 refrigerant gas leakage detection method according to claim 2, wherein: The infrared sensor is a dual-channel infrared sensor having a first detector corresponding to a detection channel and a second detector corresponding to a reference channel. A first signal change rate x1 of the optical signal received by the first detector reflects at least a change in the R290 refrigerant gas, and a second signal change rate x2 of the optical signal received by the second detector reflects at least a change in the environment. The step S11 specifically includes: Step S111: Obtain state information of the reflecting surface at least according to the second signal change rate x2.

4. The R290 refrigerant gas leakage detection method according to claim 3, wherein: The step S111 specifically includes: Step S1111, obtaining the first signal change rate x1 and the second signal change rate x2; Step S1112: If, within a first preset time, both the optical signal received by the first detector and the optical signal received by the second detector decrease, and x1<λ1, x2<λ1, and |x1-x2|<λ2, it is determined that a temperature change occurs in the infrared chamber and the reflective surface is in the non-condensing / non-frosting state; Within a first preset time, if the optical signal received by the first detector and the optical signal received by the second detector both decrease, and x1<λ1, x2<λ1, and |x1-x2|>λ2, it is determined that a temperature change occurs in the infrared chamber, the reflecting surface is in the non-condensing / non-frosting state, and R290 refrigerant gas is present; If the optical signal received by the first detector and the optical signal received by the second detector both decrease within the second preset time and |x1-x2|<λ2, and the rate of change x2 of the second signal increases within the third preset time and x2>λ3, it is determined that the reflective surface is in the condensation / frosting state; If the optical signal received by the first detector and the optical signal received by the second detector both decrease and |x1-x2|<λ2 within the second preset time, and change to x1>x2>λ3 within the third preset time, it is determined that the reflecting surface is in the condensation / frosting state and R290 refrigerant gas is suspected to be present; Wherein, λ1 is a first preset threshold, λ2 is a second preset threshold, λ3 is a third preset threshold, and λ2<λ1<λ3.

5. The R290 refrigerant gas leakage detection method according to claim 3, wherein: A temperature sensor is also provided; The step S111 specifically includes: Step S1111′, obtaining the first signal change rate x1 and the second signal change rate x2; Step S1112′: within a first preset time, if the temperature change detected by the temperature sensor is greater than or equal to a fourth preset threshold, and if the light signal received by the second detector decreases and x2<λ1, then it is determined that a temperature change occurs in the infrared chamber and the reflecting surface is in the non-condensing / non-frosting state; if the light signal received by the second detector decreases within a second preset time, and within a third preset time, the rate of change x2 of the second signal increases and x2>λ3, then it is determined that the reflecting surface is in the condensing / frosting state; If the temperature change detected by the temperature sensor is less than a fourth preset threshold, it is determined that the reflective surface is in the non-condensing / non-frosting state.

6. The R290 refrigerant gas leakage detection method according to claim 2, wherein: The step S11 specifically includes: Step S111', using the temperature and humidity sensor to obtain the ambient temperature and humidity; Step S112': within the first preset time, if the ambient temperature rises from below zero to zero degrees Celsius or above, and there is humidity in the air, it is determined that the reflective surface is in a frosted state; within the first preset time, if the ambient temperature rises from above zero degrees Celsius and the ambient humidity is greater than or equal to the condensation humidity critical point at that temperature, it is determined that the reflective surface is in a condensed state.

7. The R290 refrigerant gas leakage detection method according to claim 2, wherein: The infrared sensor is a dual-channel infrared sensor having a first detector corresponding to a detection channel and a second detector corresponding to a reference channel; Also includes suspected condensation / frost conditions; The step S11 specifically includes: Step S111'', determining the state of the reflecting surface according to the ambient temperature and humidity detection result of the temperature and humidity sensor to obtain a first state determination result, and determining the state of the reflecting surface according to at least a second signal change rate x2 of the light signal received by the second detector to obtain a second state determination result; Step S112'': if both the first state judgment result and the second state judgment result indicate that the reflective surface is in the condensation / frosting state, confirming that the reflective surface is in the condensation / frosting state; If the first state judgment result is a non-condensation / non-frosting state, and the second state judgment result is a condensation / frosting state, confirming that the reflective surface is in the suspected condensation / frosting state; If the first state judgment result is that the reflective surface is in the condensation / frosting state, and the second state judgment result is that the reflective surface is not in the condensation / frosting state, confirming that the reflective surface is in the suspected condensation / frosting state; If both the first state judgment result and the second state judgment result are that the infrared chamber is not in the condensation / frosting state, it is confirmed that the infrared chamber is in the non-condensation / non-frosting state.

8. The R290 refrigerant gas leakage detection method according to claim 7, wherein: The step S2 specifically includes: Step S21: If the reflecting surface is in the non-condensing / non-frosting state, the infrared sensor is used to detect in real time whether there is R290 refrigerant gas in its infrared gas chamber, and the first signal is output to the controller when the R290 refrigerant gas is detected; if the reflecting surface is in the confirmed condensation / frosting state, the auxiliary sensor is used to detect in real time whether there is R290 refrigerant gas, and the second signal is output to the controller when the R290 refrigerant gas is detected; if the reflecting surface is in the suspected condensation / frosting state, when the infrared sensor does not detect R290 refrigerant gas, no signal is output; when the infrared sensor detects R290 refrigerant gas and the auxiliary sensor does not detect R290 refrigerant gas, no signal is output; when the infrared sensor detects R290 refrigerant gas and the auxiliary sensor detects R290 refrigerant gas, the second signal is output to the controller.

9. The R290 refrigerant gas leakage detection method according to claim 1, wherein: The auxiliary sensor is one of a thermal conductivity sensor, an acoustic resonance ultrasound sensor, and a photoacoustic spectroscopy sensor; The step S2 specifically includes: step S21', starting the infrared sensor and the auxiliary sensor to detect in real time whether there is R290 refrigerant gas, if the reflecting surface is in the non-condensing / non-frosting state, the infrared sensor outputs the first signal to the controller when detecting the R290 refrigerant gas; if the reflecting surface is in the condensing / frosting state, the auxiliary sensor outputs the second signal to the controller when detecting the R290 refrigerant gas; or, the step S2 specifically includes: step S21'', if the reflecting surface is in the non-condensing / non-frosting state, using the infrared sensor The external sensor detects in real time whether R290 refrigerant gas is present in its infrared gas chamber, and outputs the first signal to the controller when the R290 refrigerant gas is detected. After the R290 refrigerant gas concentration value detected by the infrared sensor reaches the detection accuracy of the auxiliary sensor, the auxiliary sensor is started to detect in real time whether R290 refrigerant gas is present, and the second detected signal is output to the controller. If the reflecting surface is in the condensation / frosting state, the auxiliary sensor is used to detect in real time whether R290 refrigerant gas is present, and the second signal is output to the controller when R290 refrigerant gas is detected.

10. The R290 refrigerant gas leakage detection method according to claim 1, wherein: The auxiliary sensor is one of a MOX sensor, an electrochemical sensor, and a thermal catalytic sensor; When the reflecting surface is in the condensation / frosting state, the MOX sensor, the electrochemical sensor or the thermocatalytic sensor is in the on state; when the reflecting surface is in the non-condensation / non-frosting state, the MOX sensor, the electrochemical sensor or the thermocatalytic sensor is in the off state.

11. An R290 refrigerant gas leakage detection device, characterized in that: The R290 refrigerant gas leakage detection device includes: The housing is provided with an air inlet for allowing the gas to be measured to enter the housing; An infrared sensor is disposed in the housing, and its infrared air chamber is connected to the air inlet to allow the gas to be tested to pass through for detection; an auxiliary sensor disposed in the housing and in communication with the air inlet, for detecting whether R290 refrigerant gas is present in the gas to be tested, wherein the detection principle of the auxiliary sensor is different from that of the infrared sensor, and the auxiliary sensor is not affected by condensation / frosting; and The controller is electrically connected to the infrared sensor and the auxiliary sensor, and is used to obtain status information of the reflective surface in the infrared chamber and receive the first signal of the infrared sensor or the second signal of the auxiliary sensor according to the status information.

12. The R290 refrigerant gas leakage detection device according to claim 11, wherein: The controller performs the steps of the R290 refrigerant gas leakage detection method according to any one of claims 1 to 10; The auxiliary sensor is a thermal conductivity sensor, an acoustic resonance ultrasonic sensor, a MOX sensor, an electrochemical sensor or a thermal catalytic sensor; The R290 refrigerant gas leakage detection device further includes a temperature and humidity sensor disposed in the housing for detecting ambient temperature and humidity; The controller is electrically connected to the temperature and humidity sensor; The housing includes an upper cover and a lower cover, the upper cover and the lower cover are buckled and connected to form a accommodating cavity, and the air inlet is provided on the upper cover or the lower cover; The R290 refrigerant gas leakage detection device further includes: a waterproof and breathable membrane, provided at the air inlet; and At least one electromagnetic shielding cover, disposed in the accommodating cavity, and containing the infrared sensor and / or the auxiliary sensor; The controller is disposed in the accommodating cavity.

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