Gas leakage detection method and detection circuit

Abstract

The invention provides a gas leakage detection method and circuit, and the method comprises the steps: obtaining a plurality of calibration electric signals of calibration concentrations of target gas through employing a gas concentration sensor, and forming a concentration electric signal calibration table; determining the linear correlation between the gas concentration of the target gas and the detection electric signal based on a concentration electric signal calibration table; obtaining a leakage threshold value corresponding to the gas alarm concentration by combining the concentration electric signal calibration table and the linear correlation; a gas concentration sensor is adopted to obtain the real-time detection concentration of target gas in real time, and when the real-time detection concentration reaches a leakage threshold value, an alarm signal is sent out. The method has no destructive influence on the detection environment and no material loss, and is simple in structure, stable in performance, convenient to use, stable in signal and long in service life by detecting the concentration and leakage state of the target gas, and the corresponding detection circuit is small in structure and convenient to mount and dismount.

Description

Technical Field

[0001] The present invention relates to the field of gas leakage detection, and more specifically, to a gas leakage detection method and detection circuit. Background Art

[0002] Traditional gas leak detection methods generally use electrochemical methods, but electrochemical methods are generally accompanied by chemical reactions, which will inevitably cause a certain degree of change to the target environment being detected. It can be regarded as a destructive test to a certain extent, and generally there will be a continuous loss of some chemical substances. Summary of the Invention

[0003] The purpose of the embodiments of the present application is to provide a gas leakage detection method and detection circuit to solve the technical problem of chemical substance loss in existing gas leakage detection.

[0004] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are: In one aspect, a method for detecting a gas leak is provided, comprising the following steps: S100: Using a gas concentration sensor, obtaining calibration electrical signals of several calibration concentrations of the target gas, and forming a concentration electrical signal calibration table; S200: Determine the linear correlation between the gas concentration of the target gas and the detection electrical signal based on the concentration electrical signal calibration table; S300: Acquire a leakage threshold corresponding to the gas alarm concentration by combining the concentration electrical signal calibration table and the linear correlation; S400: using the gas concentration sensor to obtain the real-time detection concentration of the target gas in real time, and when the real-time detection concentration reaches the leakage threshold, issuing an alarm signal.

[0005] In one embodiment, step S100 includes the following steps: S110: Acquire a first calibration electrical signal corresponding to a first calibration concentration; S120: Acquire a second calibration electrical signal corresponding to a second calibration concentration; S130: Obtaining a third calibration electrical signal corresponding to a third calibration concentration; S140: Acquire a fourth calibration electrical signal corresponding to a fourth calibration concentration, wherein the first calibration concentration, the second calibration concentration, the third calibration concentration, and the fourth calibration concentration are different.

[0006] In one embodiment, the PPM of the first calibration concentration is 0%, the PPM of the second calibration concentration is 10%, the PPM of the third calibration concentration is 40%, and the PPM of the fourth calibration concentration is 50%.

[0007] In one embodiment, the first calibration concentration is 0% of the measuring range of the gas concentration sensor, the second calibration concentration is 10% of the measuring range of the gas concentration sensor, the third calibration concentration is 40% of the measuring range of the gas concentration sensor, and the fourth calibration concentration is 50% of the measuring range of the gas concentration sensor.

[0008] In one embodiment, step S400 includes the following steps: S410: Acquire an initial concentration electrical signal using the gas concentration sensor; S420: Using a temperature sensor to obtain the current temperature and calculate a temperature compensation incremental electrical signal; S430: Calculating the real-time detection concentration based on the difference between the initial concentration electrical signal and the temperature-compensated incremental electrical signal.

[0009] In one embodiment, in step S420, the current temperature is recorded as Tmpr_TRaw, the calibration temperature is recorded as TComp_TRawBase, the difference between the current temperature and the calibration temperature is recorded as Tmpr_DltTRaw, and the temperature compensation incremental electrical signal is recorded as Sens_DltSRaw. Then: Sens_DltSRaw=Tcomp_Coe0+Tcomp_Coe1*(Tmpr_DltTRaw)+Tcomp_Coe2*(Tmpr_DltTRaw)*(Tmpr_DltTRaw)+Tcomp_Coe3*(Tmpr_DltTRaw)*(Tmpr_DltTRaw)*(Tmpr_DltTRaw); Among them, Tcomp_Coe0, Tcomp_Coe1, Tcomp_Coe2, and Tcomp_Coe3 are the zero-order temperature compensation coefficient, the first-order temperature compensation coefficient, the second-order temperature compensation coefficient, and the third-order temperature compensation coefficient, respectively.

[0010] In one embodiment, before step S100, the method further includes the following steps: S510: At the calibration temperature, using the gas concentration sensor to obtain a first temperature scale electrical signal corresponding to a PPM of the target gas of 0; S520: At the first reference temperature, using the gas concentration sensor to obtain a second temperature scale electrical signal corresponding to a PPM of the target gas of 0; S530: At the second reference temperature, using the gas concentration sensor to obtain a third temperature scale electrical signal corresponding to a PPM of the target gas of 0; S540: Under the third reference temperature, using the gas concentration sensor to obtain a fourth temperature scale electrical signal corresponding to a PPM of the target gas of 0; S550: Based on steps S510 to S540, the zero-order temperature compensation coefficient Tcomp_Coe0, the first-order temperature compensation coefficient Tcomp_Coe1, the second-order temperature compensation coefficient Tcomp_Coe2, and the third-order temperature compensation coefficient Tcomp_Coe3 are calculated.

[0011] In one embodiment, after step S430, the following steps are further included: S441: using a humidity sensor to obtain humidity increment; S442: Calculating a humidity compensation amount based on the humidity increment and the temperature coefficient; S443: Obtaining the PPM concentration before moisture compensation based on the difference between the initial concentration electrical signal and the temperature compensation incremental electrical signal; S444: Perform humidity compensation on the PPM concentration before humidity compensation using the humidity compensation amount to obtain the real-time detected concentration.

[0012] In one embodiment, after step S444, the following steps are further included: S451: Using the air pressure sensor to obtain the air pressure increment; S452: Obtaining an air pressure parameter based on the air pressure increment; S453: Divide the real-time detection concentration after humidity compensation by the air pressure parameter to obtain the real-time detection concentration after air pressure compensation.

[0013] In one embodiment, step S400 further includes the following steps: converting the PPM concentration value of the real-time detected concentration into an LFL concentration value.

[0014] In another aspect, a gas leak detection circuit is provided, comprising a thermal conductivity chip module, an operational amplifier, and a microcontroller unit electrically connected in sequence, wherein the thermal conductivity chip module is used to sense the concentration of a target gas in a measured environment; the microcontroller unit comprises a memory, a processor, and a computer program stored in the memory and executable on the processor; when the processor executes the computer program, the gas leak detection method described in any one of the above items is implemented, and an alarm signal is sent through the microcontroller unit.

[0015] The gas leakage detection method and detection circuit provided by the embodiment of the present application have at least the following beneficial effects: in electrochemical detection, electrodes or reaction reagents will be continuously consumed during the detection process and need to be replaced regularly to ensure accuracy, which not only increases the cost of consumables, but may also cause detection errors due to untimely replacement. This method uses a gas concentration sensor to detect thermal properties to detect gas concentration, form a concentration electrical signal calibration table, and then determine the linear correlation between gas concentration and detection electrical signal; combining the concentration electrical signal calibration table and the linear correlation, obtain the leakage threshold corresponding to the gas alarm concentration, so that when the leakage threshold is reached, real-time detection and alarm are achieved, and this method has no destructive effect on the detection environment, and no material loss is generated, and it has a simple structure, stable performance, and is easy to use. By checking the concentration of the target gas and the leakage status, the signal is stable and has a long service life. The corresponding detection circuit structure is compact and easy to install and disassemble. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or exemplary technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 A schematic diagram of a flow chart of a gas leakage detection method provided in an embodiment of the present application; Figure 2 A circuit diagram of a power module provided in an embodiment of the present application; Figure 3 A circuit diagram of a thermal conductivity chip module provided in an embodiment of the present application; Figure 4 is a circuit diagram of a voltage divider resistor module provided in one embodiment of the present application; Figure 5 is a circuit diagram of an operational amplifier provided in one embodiment of the present application; Figure 6 Schematic diagram of a concentration electrical signal calibration table provided in one embodiment of the present application; Figure 7 This is a flow chart of step S400 in one embodiment of the present application; Figure 8 This is a schematic diagram of a temperature compensation process in one embodiment of the present application; Figure 9 Schematic diagram of the humidity compensation process in one embodiment of the present application; Figure 10 Schematic diagram of the process of air pressure compensation in one embodiment of the present application; Figure 11This is a circuit connection diagram of a thermal conductivity chip module, a voltage divider resistor module, and an operational amplifier in one embodiment of the present application; Figure 12 A circuit diagram of a micro control unit provided in one embodiment of the present application.

[0018] Among them, the main marks of the drawings in the figure are: 100, power supply module; 200, thermal conductivity chip module; 300, voltage divider resistor module; 400, operational amplifier; 500, micro control unit. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0020] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0022] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, when the phrases "in one embodiment" or "in some embodiments" appear in various places throughout this specification, not all references are to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Example

[0023] See also Figure 1 The gas leakage detection method provided in the embodiment of the present application is now described. The gas leakage detection method comprises the following steps: S100: Using a gas concentration sensor, obtain calibration electrical signals of several calibration concentrations of the target gas to form a concentration electrical signal calibration table. In some embodiments, combined with Figure 3、 Figure 5 、 Figure 11 and Figure 12 The gas concentration sensor includes a thermal conductive chip module 200 ( Figure 3 )、Operational amplifier 400( Figure 5 ) and the micro control unit 500 ( Figure 12 ), thermal conductivity chip module 200 senses changes in ambient air properties, then uses operational amplifier 400 to perform preliminary signal processing. The result is then transmitted to microcontroller unit (MCU) 500 for further processing, turning it into user-friendly data for easy integration into various application systems. Operational amplifier 400 can optionally be a signal processing IC (Integrated Circuit).

[0024] S200: Based on the concentration electrical signal calibration table, determine the linear correlation between the gas concentration of the target gas and the detection electrical signal. The linear correlation can be positive or negative, and there is no need to solve the specific functional relationship. Generally, the gas concentration and the detection electrical signal are positively correlated, but because there may be polarity reversal elements in the detection circuit, the two are negatively correlated. This method does not need to consider whether there are polarity elements in the detection circuit, and does not need to know the circuit design details in advance. Through the multiple calibration electrical signals finally output, it is determined whether it is positively correlated or negatively correlated, and the rising and falling relationship between the gas concentration and the detection electrical signal is obtained.

[0025] S300: Combine the concentration electrical signal calibration table and the linear correlation to obtain the leakage threshold corresponding to the gas alarm concentration. For example, based on the linear correlation, it is determined that the gas concentration and the detection electrical signal are positively correlated. Then, the gas alarm concentration is combined with the concentration electrical signal calibration table and the corresponding detection electrical signal is calculated through interpolation. The leakage threshold can be based on the gas concentration or the detection electrical signal, and is not specifically limited here. When the leakage threshold is the gas concentration, the gas alarm concentration only needs to be input into the gas concentration sensor, and the microcontroller unit 500 will calculate the corresponding detection electrical signal. When the leakage threshold is the detection electrical signal, the staff will calculate the corresponding detection electrical signal and then input it into the microcontroller unit 500.

[0026] S400: A gas concentration sensor is used to obtain the target gas's real-time concentration. When the real-time concentration reaches the leakage threshold, an alarm signal is issued. This method requires only binary judgment, greatly reducing the detection difficulty and eliminating complex calculations, thus reducing calculation errors and improving detection accuracy.

[0027] In electrochemical detection, electrodes or reaction reagents will be continuously consumed during the detection process and need to be replaced regularly to ensure accuracy. This not only increases the cost of consumables, but may also cause detection errors due to untimely replacement. The present method uses a gas concentration sensor to detect thermal properties to detect gas concentration, forming a concentration electrical signal calibration table, and then determining the linear correlation between gas concentration and the detection electrical signal; combining the concentration electrical signal calibration table and the linear correlation, the leakage threshold corresponding to the gas alarm concentration is obtained, so that when the leakage threshold is reached, real-time detection and alarm are achieved. The present method has no destructive impact on the detection environment, and no material loss occurs. It has a simple structure, stable performance, and is easy to use. By checking the concentration of the target gas and whether it is leaking or not, the signal is stable and has a long service life. The corresponding detection circuit structure is compact and easy to install and disassemble. In addition, the present method does not need to calculate the specific functional relationship between the concentration and the electrical signal, but only needs to obtain the linear correlation between the two through calibration data. In some embodiments, step S100 includes the following steps: S110: Obtain a first calibration electrical signal SRaw1 corresponding to a first calibration concentration.

[0028] S120: Obtain a second calibration electrical signal SRaw2 corresponding to a second calibration concentration.

[0029] S130: Obtain a third calibration electrical signal SRaw3 corresponding to a third calibration concentration.

[0030] S140: Obtain a fourth calibration electrical signal SRaw4 corresponding to a fourth calibration concentration, wherein the first calibration concentration, the second calibration concentration, the third calibration concentration, and the fourth calibration concentration are different.

[0031] In order to obtain the linear correlation between the electrical signal and the concentration of the target gas, this method needs to be calibrated with different calibration concentrations of the target gas before use in leak detection, and the corresponding calibration electrical signal SRaw is detected and made into a table (see Figure 6 ), forming a relationship from the calibration electrical signal SRaw to the concentration data of the target gas for data processing.

[0032] Among them, calibration data with more than three calibration concentrations can more comprehensively reflect the changing patterns between gas concentration and electrical signals, more reliably eliminate accidental error interference, avoid overall detection failure caused by single-point drift, and lay the foundation for detection accuracy. Even if the sensor has slight nonlinearity in a local area, the overall trend judgment of four points can still reliably establish linear correlation, eliminating the need for high-precision, high-cost components, while ensuring detection accuracy and controlling hardware costs. Specifically, there are only four calibration concentrations, and based on the linear relationship established by the four points (such as fitting a straight line through the least squares method), the electrical signal can be quickly converted into a concentration value through simple linear interpolation or formula calculation during real-time detection. Without the need for complex algorithms, it simplifies the difficulty of data processing and ensures the reliability of the core logic. This simplicity reduces the computing burden of the MCU and reduces the source of errors in real-time processing.

[0033] In some embodiments, the PPM of the first calibration concentration is 0%, which accurately captures the reference value of the electrical signal when there is no target gas, eliminates the influence of sensor zero drift or environmental background interference, and ensures the accuracy of low-concentration leak detection. The PPM of the second calibration concentration is 10%, which corresponds to a slight leakage scenario and can effectively identify the early leakage state, provide data support for timely warning, and avoid safety risks caused by the spread of the leakage. The PPM of the third calibration concentration is 40%, and the PPM of the fourth calibration concentration is 50%. The two cover the concentration range close to or reaching the leakage threshold, ensuring that the detection accuracy can still be maintained in the stage of intensified leakage, and providing a direct reference for the setting of the leakage threshold. Among them, the local nonlinear effect is weakened by multi-point fitting, so that the linear correlation judgment is closer to the actual detection law.

[0034] In some embodiments, the first calibration concentration is 0% of the gas concentration sensor's range, with 0% of the range serving as the reference zero point to eliminate environmental background interference. The second calibration concentration is 10% of the gas concentration sensor's range, with 10% of the range corresponding to early trace leaks, ensuring low-concentration detection accuracy. The third calibration concentration is 40% of the gas concentration sensor's range, and the fourth calibration concentration is 50% of the gas concentration sensor's range. The ranges of gas concentration sensors of different models may vary significantly. Setting the calibration concentration as a ratio of the range rather than an absolute value allows the same detection method to be applied to sensors of different specifications, significantly improving the method's versatility and compatibility.

[0035] It can be understood that in step S100, the calibration concentrations may be four groups, or may be more than four groups, such as five groups or six groups, which is not limited here.

[0036] In some embodiments, combined Figure 7 In step S400, the following steps are included: S410: Obtain an initial concentration electrical signal using a gas concentration sensor.

[0037] S420: Using a temperature sensor to obtain the current temperature, and calculating a temperature compensation incremental electrical signal.

[0038] S430: Calculate the real-time detection concentration based on the difference between the initial concentration electrical signal and the temperature compensation incremental electrical signal.

[0039] Thermal conductivity gas sensors rely on the thermal properties of gases (such as thermal conductivity), with temperature being the key factor influencing these properties. By acquiring the current temperature in real time through a temperature sensor, the corresponding temperature-compensated incremental electrical signal (i.e., the signal error caused by temperature deviation) is calculated and this error is removed from the initial concentration signal. This minimizes the impact of temperature on the test results and ensures consistent concentration detection across different temperature environments. This eliminates the influence of temperature on detection accuracy and improves measurement stability.

[0040] In some embodiments, in step S420, the current temperature is recorded as Tmpr_TRaw, the calibration temperature is recorded as TComp_TRawBase, the difference between the current temperature Tmpr_TRaw and the calibration temperature TComp_TRawBase is recorded as Tmpr_DltTRaw, and the temperature compensation incremental electrical signal is recorded as Sens_DltSRaw. Then: Sens_DltSRaw=Tcomp_Coe0+Tcomp_Coe1*(Tmpr_DltTRaw)+Tcomp_Coe2*(Tmpr_DltTRaw)*(Tmpr_DltTRaw)+Tcomp_Coe3*(Tmpr_DltTRaw)*(Tmpr_DltTRaw)*(Tmpr_DltTRaw).

[0041] Among them, Tcomp_Coe0, Tcomp_Coe1, Tcomp_Coe2, and Tcomp_Coe3 are the zero-order temperature compensation coefficient, the first-order temperature compensation coefficient, the second-order temperature compensation coefficient, and the third-order temperature compensation coefficient, respectively.

[0042] The effect of temperature on thermal conductivity gas sensors is not a simple linear relationship. In the low temperature range (e.g., -10°C to 20°C), the effect of temperature changes on gas thermal conductivity may be approximately linear. In the medium to high temperature range (e.g., 20°C to 50°C), factors such as sensor self-heating and increased gas molecular motion may cause quadratic or cubic nonlinearity (e.g., signal deviation increases rapidly after a certain temperature rise). A cubic polynomial (containing terms from zero to three degrees) can flexibly fit this complex nonlinear relationship through coefficients (Tcomp_Coe0 to Tcomp_Coe3). Compared to using linear compensation (linear terms) or quadratic compensation alone, this significantly reduces compensation error across different temperature ranges, making the corrected signal closer to the electrical signal corresponding to the true concentration. This ensures that the alarm threshold is based on a true, reliable signal, improving the safety factor of the entire detection system.

[0043] In some embodiments, combined Figure 8 Before step S100, the method further includes the following steps: S510: Under the calibration temperature, a gas concentration sensor is used to obtain a first temperature scale electrical signal corresponding to a target gas PPM of 0.

[0044] S520: At the first reference temperature, using a gas concentration sensor to obtain a second temperature scale electrical signal corresponding to a target gas PPM of 0.

[0045] S530: At the second reference temperature, a gas concentration sensor is used to obtain a third temperature scale electrical signal corresponding to a target gas PPM of 0.

[0046] S540: At the third reference temperature, using a gas concentration sensor to obtain a fourth temperature scale electrical signal corresponding to a target gas PPM of 0.

[0047] S550: Based on steps S510 to S540, the zero-order temperature compensation coefficient Tcomp_Coe0, the first-order temperature compensation coefficient Tcomp_Coe1, the second-order temperature compensation coefficient Tcomp_Coe2, and the third-order temperature compensation coefficient Tcomp_Coe3 are calculated.

[0048] When the target gas concentration is zero, the sensor's electrical signal drift is caused solely by temperature changes (excluding interference from gas concentration). Steps S510 through S540 list four equations, which can be solved simultaneously to yield four temperature compensation coefficients (Tcomp_Coe0 through Tcomp_Coe3).

[0049] The initial concentration electrical signal is Sens_SRaw, and the specific calculation code for the temperature compensation incremental electrical signal Sens_DltSRaw is as follows: Tcomp_X = Tmpr_DltTRaw; Usr_TComp_Polynomial_Cubic2(Tcomp_X,&Tcomp_Y); Sens_DltSRaw = Tcomp_Y; Sens_Raw_After_TmpComp = Sens_SRaw - Sens_DltSRaw; uint8_t Tcomp_Flag; float Tcomp_X; float Tcomp_Coe0; float Tcomp_Coe1; float Tcomp_Coe2; float Tcomp_Coe3; float Tcomp_Y; void Usr_TComp_Polynomial_Cubic2(float nbr, float *out) { float Temp0; float Temp1; if((Tcomp_Flag<4)||(TComp_TRawBase == 0)||(TComp_TRawBase==0xFFFF)) { / / if without correct parameters; *out = 0; return; } / / printf("nbr,%d,", nbr); Temp0 = nbr*nbr*nbr; Temp0 *= Tcomp_Coe3; Temp1 = nbr*nbr; Temp1 *= Tcomp_Coe2; Temp0 += Temp1; Temp1 = nbr; Temp1 *= Tcomp_Coe1; Temp0 += Temp1; Temp0 += Tcomp_Coe0; / / printf("Poly,%d,", tmp_A_Item); if(Temp0>= (float)(32766.9)) { *out = 32767; return; } else if (Temp0<= (float)(-32766.9)) { *out = -32767; return; } *out = Temp0; / / printf("return,%d,", *out); return; } In some embodiments, combined Figure 9 After step S430, the following steps are further included: S441: Use the humidity sensor to obtain the humidity increment. The humidity increment is the difference between the current humidity and the calibrated humidity. The calibrated humidity can be set to 0%.

[0050] S442: Calculate the humidity compensation based on the humidity increment and the temperature coefficient. The temperature coefficient, Tmpr_DltTRaw, is the difference between the current temperature, Tmpr_TRaw, and the calibration temperature, TComp_TRawBase. The effect of humidity on gas thermal conductivity is not fixed but varies with temperature (for example, at the same humidity, the thermal conductivity of water vapor in a high-temperature environment differs from that in a low-temperature environment). By incorporating the temperature coefficient into the calculation of humidity compensation, the humidity compensation weight can be dynamically adjusted at different temperatures, avoiding undercompensation caused by ignoring the interaction between temperature and humidity, and ensuring that humidity correction more closely reflects actual physical laws.

[0051] S443: The pre-humidity compensation PPM concentration is calculated based on the difference between the initial concentration signal and the temperature compensation incremental signal. Temperature compensation is performed first, followed by humidity compensation, making the correction logic for the two environmental factors independent. This decoupled design facilitates the separate optimization of humidity and temperature compensation parameters, reducing debugging difficulties. Furthermore, the humidity incremental signal is calculated at the calibration temperature. This makes it more scientific and rational to first compensate the initial concentration signal back to the pre-humidity compensation PPM concentration at the calibration temperature before performing humidity compensation.

[0052] S444: Humidity compensation is performed on the PPM concentration before the humidity compensation using the humidity compensation amount to obtain the real-time detection concentration. Specifically, the real-time detection concentration = the PPM concentration before the humidity compensation - the humidity compensation amount.

[0053] Introducing the humidity compensation mechanism in steps S441 to S444 is a further optimization of the gas detection environmental factors, which can effectively eliminate the interference of humidity on detection accuracy.

[0054] In one embodiment, before step S442 , a calculation formula for the humidity compensation amount H_comp is first solved: H_comp= Hcomp_Coe0 + Hcomp_Coe1×Tmpr_DltTRaw + Hcomp_Coe2×H_delta + Hcomp_Coe3×Tmpr_DltTRaw×H_delta.

[0055] The specific solution process involves fitting the humidity compensation zero-order coefficient Hcomp_Coe0 (a constant term used to correct baseline deviation), the humidity compensation temperature coefficient Hcomp_Coe1 (weight associated with the temperature parameter), the humidity compensation humidity coefficient Hcomp_Coe2 (weight associated with the humidity increment), and the humidity compensation interaction coefficient Hcomp_Coe3 (related to the cross-influence of temperature and humidity) for calibration experiments at the calibration temperature (T0). The temperature parameter Tmpr_DltTRaw is defined as Tmpr_TRaw - T0 (i.e., the difference between the current temperature Tmpr_TRaw and the calibration temperature T0). The current humidity (H_current) is read using a humidity sensor. The humidity increment (H_delta) is calculated as: current humidity H_current - calibration humidity H0 (since H0 = 0%, H_delta = H_current). The humidity compensation zero-order coefficient Hcomp_Coe0, humidity compensation temperature coefficient Hcomp_Coe1, humidity compensation humidity coefficient Hcomp_Coe2, and humidity compensation interaction coefficient Hcomp_Coe3 are solved by solving four equations.

[0056] In some embodiments, combined Figure 10 After step S444, the following steps are also included: S451: Use the air pressure sensor to obtain the air pressure increment.

[0057] S452: Based on the pressure increment, the pressure parameter is obtained. After the pressure parameter correction, the detection values ​​in all environments are normalized to the standard pressure reference, ensuring a consistent logic for determining the alarm threshold and avoiding safety risks caused by pressure differences. Specifically, the pressure parameter = 1 + k × pressure increment, where k is the pressure calibration factor.

[0058] S453: Divide the real-time detection concentration after humidity compensation by the air pressure parameter to obtain the real-time detection concentration after air pressure compensation.

[0059] Gas concentration (PPM) is essentially the number of target gas molecules per unit volume, and air pressure directly affects gas volume. When air pressure decreases (such as in high-altitude environments), the gas volume expands, and the "number of molecules per unit volume" corresponding to the same number of molecules will be falsely lower (the actual concentration remains unchanged, but the signal is displayed as low). Without air pressure compensation, the same actual concentration will be converted to different PPM values ​​at different air pressures. By correcting the air pressure parameter (dividing the signal by the air pressure parameter, essentially normalizing it to the concentration at standard air pressure), this "volume effect" error caused by air pressure fluctuations can be eliminated, making the test results more consistent with the true molecular density of the gas. This further improves detection accuracy by eliminating the interference of air pressure changes on gas concentration detection.

[0060] Specifically, the pressure calibration coefficient k is obtained through a pressure calibration experiment. The corresponding relationship between the pressure increment and the concentration deviation is established, and finally the pressure calibration coefficient k is obtained by fitting calculation. Optionally, under the calibration pressure P0, calibration temperature, and calibration humidity, the target gas uses a preset concentration, such as 2000 PPM methane, and a closed container with adjustable pressure is used to simulate an environment of 0.5~1.2 times the calibration pressure. First, the detection value C of the gas concentration sensor under different pressures P is collected. 测 , second, calculate the ideal concentration value C caused by the pressure change 理 =C0×(P / P0), third, according to 1+k×ΔP=C 理 / C 测 , obtain k, and use the least squares method to fit the k values ​​of multiple pressure points, and take the average or optimal fitting value.

[0061] In some embodiments, step S400 also includes converting the real-time detected concentration value (PPM) to a LFL value. The LFL values ​​of different combustible gases vary significantly (for example, hydrogen's LFL is approximately 4%, while ethanol's LFL is approximately 3.3%), making it difficult to compare risks using PPM values ​​alone. However, converting to a percentage of the LFL allows for a uniform risk measurement relative to the gas's lower explosive limit. Regardless of the gas type, a concentration of 10% of the LFL represents a consistent relative level of explosive risk (i.e., 10% of the lower explosive limit), facilitating the establishment of a unified safety threshold.

[0062] In some embodiments, combined Figure 2 and Figure 11The gas concentration sensor also includes a power module 100. The voltage output terminal of the power module 100 is connected to the thermal conductivity chip module 200 to independently supply power to the thermal conductivity chip module 200. The operational amplifier 400 and the microcontroller unit 500 can be powered by a power supply voltage provided by an external device. The external device can be an integrated object of the gas leak detection device. If the gas leak detection device is integrated into an air conditioner, the external device is the air conditioner.

[0063] In this embodiment of the present application, the thermal conductivity chip module 200 is independently powered by the power module 100, effectively suppressing power supply coupling interference and meeting the differentiated voltage requirements for powering the thermal conductivity chip module 200, the operational amplifier 400, and the microcontroller unit 500. Specifically, the thermal conductivity chip module 200 is prone to generating high-frequency ripple during operation. Independent power supply prevents this noise from coupling from the common power supply to the operational amplifier 400 and the microcontroller unit 500, thereby reducing analog signal acquisition errors. During gas leak detection, the thermal conductivity chip module 200 may draw sudden high currents. Independent power supply prevents load fluctuations from causing voltage drops in the microcontroller unit 500 and triggering reset failures.

[0064] In some embodiments, combined Figure 4 and Figure 11 The gas concentration sensor also includes a voltage divider resistor module 300. The negative output terminal of the thermal conductivity chip module 200 is connected to the input terminal of the voltage divider resistor module 300, and the positive output terminal of the thermal conductivity chip module 200 is connected to the positive input terminal of the operational amplifier 400. The first output terminal of the voltage divider resistor module 300 is connected to the negative input terminal of the operational amplifier 400, the second output terminal of the voltage divider resistor module 300 is connected to the analog power input terminal of the operational amplifier 400, and the output terminal of the operational amplifier 400 is connected to the microcontroller unit 500.

[0065] In the embodiment of the present application, the thermal conductivity chip module 200 can sense the concentration of the target gas in the measured environment. When the target gas concentration in the measured environment changes, the thermal conductivity chip module 200 generates an electrical signal difference and outputs a differential voltage signal. The output differential voltage signal is divided by the voltage divider resistor module 300 and input into the operational amplifier 400, where the operational amplifier 400 performs signal amplification processing to obtain the original signal value. The original signal value is then input into the microcontroller unit 500 for processing to obtain a gas leak detection result. Based on the principle that gas concentration affects thermal conductivity, this application determines the change in gas concentration by detecting changes in the gas's heat transfer ability. This can significantly shorten the warm-up process and detection time, and has lower power consumption. Unlike electrochemical sensors that suffer from material loss, the sensor of this embodiment has an extremely long service life. Furthermore, the differential voltage signal output by the thermal conductivity chip module 200 is divided by the voltage divider resistor module 300 before being input into the operational amplifier 400, ensuring that it matches the voltage processing range of the subsequent operational amplifier 400. By setting the voltage divider resistor module 300, the tiny leakage signal can be placed in the high sensitivity range of the operational amplifier 400 after voltage division by the voltage divider resistor module 300, thereby improving the operational amplifier 400's ability to resolve weak leakage signals and enhancing detection sensitivity.

[0066] Figure 2 FIG. 1 is a circuit diagram of a power module 100 provided in an embodiment of the present application. Figure 2As shown, the power module 100 includes a power control chip U1 and a first capacitor C1. The first pin (i.e., IN pin) of the power control chip U1 serves as a voltage input terminal for receiving a power voltage provided by an external device. The second pin (i.e., GND pin) of the power control chip U1 is grounded. The third pin (i.e., EN / NC pin) of the power control chip U1 serves as an enable control terminal for receiving the regulated output voltage VLDO_EN of an LDO (linear regulator). This regulated output voltage VLDO_EN controls whether the power control chip U1 is active, enabling intermittent power supply to the thermal conductivity chip module 200. For example, when the regulated output voltage VLDO_EN connected to the third pin of the power control chip U1 is high, the power control chip U1 is active, thus providing power to the thermal conductivity chip module 200. However, when the regulated output voltage VLDO_EN connected to the third pin of the power control chip U1 is low, the power control chip U1 is inactive and cannot provide power to the thermal conductivity chip module 200. The fifth pin (i.e., the OUT pin) of the power control chip U1 serves as a voltage output terminal and is connected to the thermal conductivity chip module 200 to supply power to the thermal conductivity chip module 200. The fifth pin of the power control chip U1 is also connected to the first terminal of a first capacitor C1, the second terminal of which is grounded. The first capacitor C1 can directly bypass high-frequency interference from the voltage output terminal to ground, preventing noise from being transmitted to subsequent circuits (i.e., the thermal conductivity chip module 200).

[0067] In this embodiment of the present application, an automotive-grade LDO device is used to convert an unstable input power source (such as a vehicle battery) into a stable, pure output voltage, which is then connected to the power module 100. This converts the fluctuating input into a precise, reliable regulated output, which is then connected to a load circuit such as the thermal conductivity chip module 200. This reduces temperature drift and prevents power supply ripple from contaminating the microvolt-level differential signal output by the thermal conductivity chip module 200.

[0068] Figure 3 FIG. 1 is a circuit diagram of a thermal conductive chip module 200 provided in an embodiment of the present application. Figure 3As shown, the thermal conductivity chip module 200 includes a single thermal conductivity chip U2 and a first resistor R1 arranged in series. The single thermal conductivity chip U2 includes a first heat source pin HEATER1, a second heat source pin HEATER2, a positive thermal resistor pin TH+, and a negative thermal resistor pin TH-. A thermopile is connected between the positive thermal resistor pin TH+ and the negative thermal resistor pin TH-. The positive thermal resistor pin TH+ serves as the positive output terminal of the thermal conductivity chip module 200 and is connected to the positive input terminal (i.e., the SIP pin) of the operational amplifier 400. The negative thermal resistor pin TH- serves as the negative output terminal of the thermal conductivity chip module 200 and is connected to the input terminal of the voltage divider resistor module 300. The first heat source pin HEATER1 is grounded, the second heat source pin HEATER2 is connected to the first terminal of the first resistor R1, and the second terminal of the first resistor R1 is connected to the voltage output terminal of the power module 100, i.e., to the fifth pin of the power control chip U1.

[0069] In an embodiment of the present application, when a specified voltage is applied between the first heat source pin HEATER1 and the second heat source pin HEATER2, a stable heat source is generated between the first heat source pin HEATER1 and the second heat source pin HEATER2, and heat is transferred to the surface of the thermopile through the gas molecules in the measured environment. When the target gas concentration in the measured environment changes, an electrical signal difference can be generated between the positive thermistor pin TH+ and the negative thermistor pin TH-, and the differential signal is detected; the target gas concentration is proportional to the heat carried by the gas molecules in the measured environment.

[0070] The size of the specified voltage can be set according to the actual application scenario. Different application scenarios correspond to different specified voltages. Therefore, gas leaks in different application scenarios can be detected, reducing the impact of environmental changes on the accuracy of detection results.

[0071] In the embodiment of the present application, the first resistor R1 is a voltage dividing resistor connected to the fifth pin of the power control chip U1 and can perform voltage dividing processing on the power voltage provided by the power module 100 .

[0072] Specifically, the first resistor R1 can be detachably connected between the second heat source pin HEATER2 of the single thermal conductivity chip U2 and the fifth pin of the power control chip U1, thereby meeting the voltage requirements of different thermal conductivity chip modules 200. Alternatively, the first resistor R1 can be an adjustable resistor, similarly meeting the voltage requirements of different thermal conductivity chip modules 200.

[0073] In the embodiment of the present application, the core principle of the thermal conductivity chip module 200 for detecting gas leaks is based on the physical difference in thermal conductivity of different gases. Leak identification is achieved by measuring the change in thermal conductivity characteristics caused by changes in gas composition. Specifically, different gas molecular structures lead to different thermal conductivity capabilities. The thermal conductivity of gases (such as R134a and R410A) is significantly lower than that of air. When gas leaks, the thermal conductivity of the local gas mixture will be significantly reduced due to the increase in gas concentration. A single thermal conductivity chip U2 can usually adopt a Wheatstone bridge design, that is, two thermistors form a bridge arm, one exposed to the ambient gas (detection end) and the other sealed in a reference gas (compensation end). When gas leaks, the heat dissipation efficiency of the detection end decreases, causing the temperature to rise, thereby generating a change in resistance value, and ultimately causing the bridge to be unbalanced, outputting a differential voltage signal.

[0074] Figure 4 FIG. 3 is a circuit diagram of a voltage divider resistor module 300 provided in an embodiment of the present application. Figure 4 As shown, the voltage divider resistor module 300 includes a second resistor R2, a third resistor R3, a fourth resistor R4, and a second capacitor C2. The first end of the second resistor R2, serving as the second output of the voltage divider resistor module 300, is connected to the analog power input (i.e., the SVDD pin) of the operational amplifier 400. The second end of the second resistor R2, serving as the first output of the voltage divider resistor module 300, is connected to the negative input (i.e., the SIN pin) of the operational amplifier 400. The negative output (i.e., the negative thermal resistor pin TH-) of the thermal conductivity chip module 200 is connected to the first end of the third resistor R3. The second end of the third resistor R3 is connected to the negative input (i.e., the SIN pin) of the operational amplifier 400. The second end of the third resistor R3 is also connected to the second end of the second resistor R2 and then connected to the negative input (i.e., the SIN pin) of the operational amplifier 400. The negative output (i.e., the negative thermal resistor pin TH-) of the thermal conductivity chip module 200 is also connected to the first end of the fourth resistor R4. The second end of the fourth resistor R4 is grounded. Optionally, a common mode voltage VCM is connected between the third resistor R3 and the fourth resistor R4. The second capacitor C2 is connected between the positive input terminal (ie, the SIP pin) and the negative input terminal (ie, the SIN pin) of the operational amplifier 400.

[0075] In this embodiment of the present application, the positive signal output from the positive output terminal of the thermal conductivity chip module 200 (i.e., the positive thermal resistor pin TH+) is directly connected to the non-inverting terminal of the operational amplifier 400. The negative signal output from the negative output terminal of the thermal conductivity chip module 200 (i.e., the negative thermal resistor pin TH-) is divided by a third resistor R3 and then input to the inverting terminal of the operational amplifier 400, forming a standard differential amplification structure. A second capacitor C2 is connected across the positive and negative input terminals of the operational amplifier 400 to form a differential low-pass filter, which suppresses high-frequency noise. The negative signal output from the negative output terminal of the thermal conductivity chip module 200 (i.e., the negative thermal resistor pin TH-) is divided by a third resistor R3 and a second resistor R2 and then coupled to the SVDD pin of the operational amplifier 400. This achieves common-mode tracking and noise cancellation. Specifically, the analog power supply pin can compensate for input common-mode fluctuations, and the analog power supply pin signal injection can suppress common-mode interference. Especially in weak signal scenarios, this noise elimination and interference suppression can improve the resolution of weak leakage signals and enhance the sensitivity of gas leak detection.

[0076] In this embodiment of the present application, when a gas leak occurs, the thermal conductivity chip module 200 may output a high-voltage differential signal (e.g., ±5V), exceeding the input voltage range of the operational amplifier 400 (typically ±3.3V). The voltage divider resistor module 300 proportionally attenuates the signal to match the voltage handling range of the operational amplifier 400, preventing input saturation or damage to the operational amplifier 400. Furthermore, the thermal conductivity chip module 200 has a high output impedance, and direct connection to the high input impedance of the operational amplifier 400 can easily cause signal reflections. The voltage divider resistor module 300 acts as a buffer layer, reducing signal distortion caused by sensor loading. To address the wide dynamic range of both minute leakage signals (mV level) and large leakage signals (V level), the voltage divider resistor module 300 allows for adjustable amplification. For example, in the high-voltage range, enabling voltage division prevents overloading of the operational amplifier 400. In the low-voltage range, bypassing the voltage divider resistor allows for direct amplification of weak signals, improving resolution and detection sensitivity.

[0077] Figure 5 This is a circuit diagram of an operational amplifier 400 provided in one embodiment of the present application. In some embodiments, operational amplifier 400 is an instrumentation-grade programmable operational amplifier 400. The instrumentation-grade programmable operational amplifier 400 can adjust gain in real time via a digital interface without replacing external resistors, achieving a gain error of less than 0.01%, thus avoiding the accuracy loss associated with resistor temperature drift in traditional op amps.

[0078] In some embodiments, the voltage output terminal of the power module 100 can intermittently power the thermal conductivity chip module 200. The thermal conductivity chip module 200 only requires high current heating during the detection cycle. Intermittent power supply allows it to enter a microampere-level sleep state when idle, thereby reducing power consumption and extending device life. The power module 100 can be linked with the microcontroller unit 500 to achieve on-demand power supply.

[0079] Figure 12 This is a circuit diagram of a microcontroller unit 500 provided in one embodiment of the present application. In some embodiments, the microcontroller unit 500 is connected to an operational amplifier 400 to receive the original signal value obtained through signal amplification processing by the operational amplifier 400. The microcontroller unit 500 performs computations on the detected original signal value to ultimately determine a leakage determination result. The microcontroller unit 500 performs computations on the detected original signal value to ultimately determine a leakage determination result, which is conventional technology and will not be further described here. Example

[0080] The present application provides a gas leak detection circuit, comprising a thermal conductivity chip module 200, an operational amplifier 400, and a microcontroller unit 500 electrically connected in sequence. The thermal conductivity chip module 200 is used to sense the concentration of a target gas in a measured environment. The microcontroller unit 500 includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the gas leak detection method according to any one of the first embodiments is implemented, and an alarm signal is sent through the microcontroller unit 500.

[0081] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0082] The memory can be an internal storage unit of the operational amplifier 400 or an external storage device of the operational amplifier 400, such as a plug-in hard drive, a SmartMedia Card (SMC), a Secure Digital (SD) card, a flash memory card, etc., configured for the operational amplifier 400. Furthermore, the memory can include both the internal storage unit of the operational amplifier 400 and an external storage device. The memory is used to store the computer program and other programs and data required by the terminal device. The memory can also be used to temporarily store data that has been output or is about to be output.

[0083] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0084] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0085] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0086] In the embodiments provided in this application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are merely illustrative. For example, the division of modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0087] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0088] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0089] If the integrated module / unit is implemented as a software functional unit and sold or used as a standalone product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application can implement all or part of the process steps in the above-mentioned method embodiments by using a computer program to instruct the relevant hardware. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of each of the above-mentioned method embodiments. The computer program includes computer program code, which can be in source code form, object code form, executable file, or some intermediate form. Computer-readable media can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, removable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signals, telecommunications signals, and software distribution media. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased based on the requirements of legislation and patent practice in a jurisdiction. For example, in some jurisdictions, based on legislation and patent practice, computer-readable media does not include electric carrier signals and telecommunications signals.

[0090] The embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps in each method embodiment in embodiment 1 are implemented.

[0091] The embodiment of the present application further provides a computer program product. When the computer program product is run on a mobile terminal, the mobile terminal can implement the steps of each method embodiment in the above-mentioned embodiment 1 when executing the computer program product.

[0092] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0093] The above are merely optional embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for detecting gas leakage, characterized in that: The following steps are involved: S100: Using a gas concentration sensor, obtaining calibration electrical signals of several calibration concentrations of the target gas, and forming a concentration electrical signal calibration table; S200: Determine the linear correlation between the gas concentration of the target gas and the detection electrical signal based on the concentration electrical signal calibration table; S300: Acquire a leakage threshold corresponding to the gas alarm concentration by combining the concentration electrical signal calibration table and the linear correlation; S400: using the gas concentration sensor to obtain the real-time detection concentration of the target gas in real time, and when the real-time detection concentration reaches the leakage threshold, issuing an alarm signal.

2. The gas leakage detection method according to claim 1, wherein: Step S100 includes the following steps: S110: Acquire a first calibration electrical signal corresponding to a first calibration concentration; S120: Acquire a second calibration electrical signal corresponding to a second calibration concentration; S130: Obtaining a third calibration electrical signal corresponding to a third calibration concentration; S140: Acquire a fourth calibration electrical signal corresponding to a fourth calibration concentration, wherein the first calibration concentration, the second calibration concentration, the third calibration concentration, and the fourth calibration concentration are different.

3. The gas leakage detection method according to claim 2, wherein: The PPM of the first calibration concentration is 0%, the PPM of the second calibration concentration is 10%, the PPM of the third calibration concentration is 40%, and the PPM of the fourth calibration concentration is 50%; Alternatively, the first calibration concentration is 0% of the measuring range of the gas concentration sensor, the second calibration concentration is 10% of the measuring range of the gas concentration sensor, the third calibration concentration is 40% of the measuring range of the gas concentration sensor, and the fourth calibration concentration is 50% of the measuring range of the gas concentration sensor.

4. The gas leakage detection method according to claim 1, wherein: In step S400, the following steps are included: S410: Acquire an initial concentration electrical signal using the gas concentration sensor; S420: Using a temperature sensor to obtain the current temperature and calculate a temperature compensation incremental electrical signal; S430: Calculating the real-time detection concentration based on the difference between the initial concentration electrical signal and the temperature-compensated incremental electrical signal.

5. The gas leakage detection method according to claim 4, wherein: In step S420, the current temperature is recorded as Tmpr_TRaw, the calibration temperature is recorded as TComp_TRawBase, the difference between the current temperature and the calibration temperature is recorded as Tmpr_DltTRaw, and the temperature compensation incremental electrical signal is recorded as Sens_DltSRaw. Then: Sens_DltSRaw=Tcomp_Coe0+Tcomp_Coe1*(Tmpr_DltTRaw)+Tcomp_Coe2*(Tmpr_DltTRaw)*(Tmpr_DltTRaw)+Tcomp_Coe3*(Tmpr_DltTRaw)*(Tmpr_DltTRaw)*(Tmpr_DltTRaw); Among them, Tcomp_Coe0, Tcomp_Coe1, Tcomp_Coe2, and Tcomp_Coe3 are the zero-order temperature compensation coefficient, the first-order temperature compensation coefficient, the second-order temperature compensation coefficient, and the third-order temperature compensation coefficient, respectively.

6. The gas leakage detection method according to claim 5, wherein: Before step S100, the method further includes the following steps: S510: At the calibration temperature, using the gas concentration sensor to obtain a first temperature scale electrical signal corresponding to a PPM of the target gas of 0; S520: At the first reference temperature, using the gas concentration sensor to obtain a second temperature scale electrical signal corresponding to a PPM of the target gas of 0; S530: At the second reference temperature, using the gas concentration sensor to obtain a third temperature scale electrical signal corresponding to a PPM of the target gas of 0; S540: Under the third reference temperature, using the gas concentration sensor to obtain a fourth temperature scale electrical signal corresponding to a PPM of the target gas of 0; S550: Based on steps S510 to S540, the zero-order temperature compensation coefficient Tcomp_Coe0, the first-order temperature compensation coefficient Tcomp_Coe1, the second-order temperature compensation coefficient Tcomp_Coe2, and the third-order temperature compensation coefficient Tcomp_Coe3 are calculated.

7. The gas leakage detection method according to claim 4, wherein: After step S430, the following steps are further included: S441: using a humidity sensor to obtain humidity increment; S442: Calculating a humidity compensation amount based on the humidity increment and the temperature coefficient; S443: Obtaining the PPM concentration before moisture compensation based on the difference between the initial concentration electrical signal and the temperature compensation incremental electrical signal; S444: Perform humidity compensation on the PPM concentration before humidity compensation using the humidity compensation amount to obtain the real-time detected concentration.

8. The gas leakage detection method according to claim 7, wherein: After step S444, the following steps are further included: S451: Using the air pressure sensor to obtain the air pressure increment; S452: Obtaining an air pressure parameter based on the air pressure increment; S453: Divide the real-time detection concentration after humidity compensation by the air pressure parameter to obtain the real-time detection concentration after air pressure compensation.

9. The gas leakage detection method according to any one of claims 1 to 8, characterized in that: Step S400 also includes the following steps: converting the PPM concentration value of the real-time detection concentration into an LFL concentration value.

10. A gas leakage detection circuit, characterized in that: The device comprises a thermal conductivity chip module, an operational amplifier, and a microcontroller unit electrically connected in sequence, wherein the thermal conductivity chip module is used to sense the concentration of a target gas in a measured environment; the microcontroller unit comprises a memory, a processor, and a computer program stored in the memory and executable on the processor; when the processor executes the computer program, the gas leakage detection method according to any one of claims 1 to 9 is implemented, and an alarm signal is sent through the microcontroller unit.

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