Gas monitor and gas monitoring system

Abstract

The utility model provides a gas monitor and a gas monitoring system. The gas monitor comprises an optical module (1) and a gas distribution unit (2), the gas distribution unit (2) comprises a gas distribution block (21) and is provided with an inlet (22) for introducing purging gas, and the purging gas can be shunted through the gas distribution block (21) and flows to an optical cavity (11) of the optical module (1). And the blowing device is used for blowing out pollutants in the optical cavity (11). According to the invention, the optical chamber of the optical module of the gas monitor can be purged in a convenient, rapid and non-disassembly manner, and pollutants in the optical chamber can be removed.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of gas monitoring, and in particular, to a gas monitor and a gas monitoring system. BACKGROUND

[0002] This section is intended to provide background information to assist with understanding various technologies described herein. As the title of this section implies, what is included is in no way to be construed as an admission that what is included is prior art to what is disclosed herein. Thus, any statement or admissions should in no way serve as an acknowledgement to what is considered to be prior art to what is disclosed herein.

[0003] For the gas monitor, after a long time of operation, dust, paper scraps or other contaminants can enter the internal cavity of the optical module, resulting in reduced detection accuracy, optical module failure or false positives due to color changes of the paper strip caused by the contaminants. Therefore, the gas monitor needs to be regularly purged and maintained for the optical cavity.

[0004] In some technical solutions, the optical module of the gas monitor is directly connected with the differential pressure sensor through a pipeline, thereby enabling the differential pressure sensor to be directly connected to the internal cavity of the optical module. When cleaning of the optical module is required, the housing or side cover of the monitor needs to be first opened, and then the pipeline connected between the differential pressure sensor and the optical module needs to be pulled out, and a compressed air gun or a leather tiger used to emit cleaning gas is aimed at the internal cavity for repeated blowing, and finally the previously pulled-out pipeline is reassembled and the housing or side cover is closed when the blowing is completed.

[0005] In particular, considering that the gas monitor has a large number of detection points, the pipelines of the corresponding number of optical cavities need to be individually disassembled, cleaned and reassembled. The entire maintenance process is relatively cumbersome. In addition, the time-consuming of disassembling and assembling the pipelines is relatively long, which reduces the online time of the gas monitor and may have the risk of causing damage to the gas monitor. UTILITY MODEL CONTENT

[0006] The purpose of the present disclosure is to realize purging of the optical cavity of the optical module of the gas monitor in a convenient, fast and non-disassembly manner, and to remove the contaminants in the optical cavity.

[0007] In addition, the purpose of the present disclosure is to solve or at least alleviate one or more problems existing in the prior art.

[0008] The present disclosure solves the above problems by providing a gas monitor and a gas monitoring system. In particular, according to an aspect of the present disclosure, there is provided:

[0009] A gas monitor, wherein the gas monitor comprises an optical module and a gas distribution unit, the gas distribution unit comprising a gas distribution block and being provided with an inlet port for passing in a purge gas, the purge gas being distributable through the gas distribution block and flowing to an optical chamber of the optical module for purging contaminants in the optical chamber.

[0010] Optionally, according to an embodiment of the present disclosure, the gas distribution block is provided with a plurality of distribution outlets, each of which is connected to a purge gas input end of the optical module, and each of the purge gas input ends is in communication with the optical chamber.

[0011] Optionally, according to an embodiment of the present disclosure, the gas distribution unit further comprises a solenoid valve, which is arranged upstream of the gas distribution block and downstream of the inlet port.

[0012] Optionally, according to an embodiment of the present disclosure, the gas distribution unit further comprises a plurality of solenoid valves, which are correspondingly arranged with the distribution outlets, and the gas distribution block has a distribution passage for distributing the purge gas flowing through the inlet port to each solenoid valve.

[0013] Optionally, according to an embodiment of the present disclosure, the gas monitor comprises a flow sensor for sensing a flow of a sampling gas of a sampling gas inlet pipe of the gas monitor.

[0014] Optionally, according to an embodiment of the present disclosure, the flow sensor is a differential pressure sensor for sensing a differential pressure between an input end and an output end of a sampling gas inlet pipe of the gas monitor, and the output end is arranged in the optical chamber.

[0015] Optionally, according to an embodiment of the present disclosure, the differential pressure sensor has a first sensing end and a second sensing end, the first sensing end is connected to a sensing docking end of the gas distribution block, the sensing docking end is in communication with the optical chamber via the distribution outlet and the purge gas input end, and the second sensing end is used for sensing a gas pressure of the input end of the sampling gas inlet pipe of the gas monitor.

[0016] Optionally, according to an embodiment of the present disclosure, the gas monitor further comprises a light intensity sensor for sensing an intensity of a light receiving signal of the optical chamber.

[0017] Optionally, according to one embodiment of the present disclosure, the gas monitor further includes a controller configured to determine whether to perform the introduction of purge gas based on the cleaning interval expiration time of the gas monitor, the flow fluctuation rate of the sampling gas inlet pipe of the gas monitor, the intensity fluctuation rate of the light received signal of the optical chamber, the replacement of the paper tape for the optical chamber, or a user instruction.

[0018] Alternatively, according to one embodiment of this disclosure, the controller is integrated into the microcontroller of the gas monitor.

[0019] According to another aspect of this disclosure, a gas monitoring system is provided, wherein the gas monitoring system includes any of the above-described gas monitors and an industrial control computer.

[0020] Optionally, according to one embodiment of this disclosure, the gas monitoring system further includes an air compressor that can be connected to the inlet and is used to generate the purge gas. Attached Figure Description

[0021] Referring to the accompanying drawings, the above and other features of this disclosure will become apparent, wherein,

[0022] Figure 1 A perspective view of the connection relationship between the optical module, gas distribution unit and differential pressure sensor of a gas monitor according to the present disclosure is shown.

[0023] Figure 2 A perspective view of a gas distribution unit of a gas monitor according to the present disclosure is shown;

[0024] Figure 3 It shows Figure 2 A plan view of the gas distribution unit;

[0025] Figure 4 It shows Figure 1 A cross-sectional view of a gas monitor in monitoring mode;

[0026] Figure 5 It shows Figure 1 A cross-sectional view of a gas monitor in cleaning mode;

[0027] Figure 6 A flowchart of a cleaning method for a gas monitor according to this disclosure is shown; and

[0028] Figure 7 A flowchart of a testing method for a gas monitor according to this disclosure is shown. Detailed Implementation

[0029] It is easy to understand that, according to the technical solutions of the present disclosure, those skilled in the art can propose various structural modes and implementation modes that can be replaced with each other without changing the essential spirit of the present disclosure. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical solutions of the present disclosure, and should not be considered as the whole or as a limitation or restriction on the technical solutions of the present disclosure.

[0030] In this specification, the orientation terms mentioned or possibly mentioned in the specification, such as up, down, left, right, front, back, front, back, top, bottom, etc., are defined with respect to the structure shown in the drawings, and they are relative concepts, so they can change accordingly according to their different positions, different use states. Therefore, these or other orientation terms should not be interpreted as restrictive terms. In addition, the terms "first", "second", "third" or similar expressions are only used for description and differentiation purposes, and cannot be understood as indicating or implying the relative importance of the corresponding components.

[0031] Reference Figure 1 It shows a three-dimensional schematic diagram of the connection relationship between the optical module, the gas distribution unit and the differential pressure sensor of a gas monitor according to the present disclosure.

[0032] The gas monitor includes an optical module 1 and a gas distribution unit 2, the gas distribution unit 2 includes a gas distribution block 21 and is provided with an inlet 22 for introducing a purge gas, the purge gas can be distributed through the gas distribution block 21 and flow to the optical chamber 11 of the optical module 1, so as to purge the contaminants in the optical chamber 11.

[0033] It should be understood that the gas monitor is used to detect whether the measured gas or sample gas leaks and the gas concentration, for example, for toxic gas monitoring. The basic detection principle is, for example, that a special reagent is coated on a paper tape or a color tape, and if the measured gas exists in the ambient air, the gas will react with the reagent, causing the paper tape to change color, at which time the reflected light intensity of the light source irradiated on the paper tape will change. And the amount of change of reflected light per unit time has a certain relationship with the concentration of the measured gas in the air, so the concentration of the gas can also be determined according to the change of light. In this regard, the gas monitor can have multiple detection points, for example Figure 1 The gas monitor has 12 detection points, or 12 monitoring channels. In practice, the number of detection channels can be flexibly adjusted, and multiple (for example, 8) gas monitors can also be used to further increase the number of sampling channels, in order to improve the parallel sampling and monitoring capability of different gases. As can be seen, the optical chamber of the gas monitor is a very sensitive sensitive component, and the cleanliness inside the optical chamber significantly affects the detection accuracy of the gas monitor.

[0034] According to the background art, dust, paper scraps (e.g. produced by paper tape) or other contaminants can enter the inner chamber of the optical module after long-term operation of the gas monitor, resulting in reduced detection accuracy. Therefore, the gas monitor needs to be regularly purged and maintained. By means of the above technical solution, when cleaning is required, the purge gas can be directly introduced through the inlet, and then distributed by the gas distribution block and flowed into the optical chamber, so that the contaminants can be discharged. In this process, no disassembly is required, and the process of aeration is simple and fast. For example, the device for generating purge gas can be connected to the inlet when needed, or the device for generating purge gas can be connected to the inlet at all times, and the device can be turned on when needed, to further improve the cleaning efficiency and reduce the preparation time of the cleaning mode. The product competitiveness is also improved. In addition, the distribution effect of the gas distribution block can distribute and divide the incoming purge gas, prolonging the service life of the optical module. The way in which the contaminants leave the optical chamber will be described later in conjunction with Figure 5 The purge gas is compressed air, which is low in cost, easy to obtain, simple to operate and high in safety.

[0035] In conjunction with Figure 2 and Figure 3 , wherein, Figure 2 shows a perspective view of a gas distribution unit of a gas monitor according to the present disclosure; and Figure 3 shows Figure 2 a plan view of the gas distribution unit of

[0036] Considering that the detection points of the optical chamber of the gas monitor are usually multiple, it is feasible that the gas distribution block 21 is provided with multiple distribution outlets 211, each distribution outlet 211 is connected with a purge gas inlet end 12 of the optical module 1, and each purge gas inlet end 12 is in communication with the optical chamber 11.

[0037] It can be seen that according to the technical scheme, the use of the gas distribution block can also efficiently enable each detection point on the optical module to be correspondingly purged, and the purge gas can be more uniformly distributed, and the uniform distribution of the purge gas helps to more thoroughly remove the contaminants in the optical chamber, thereby maintaining the cleanliness thereof and improving the accuracy and stability of the measurement. This also facilitates flexible adjustment of the purge process. For example, in the cleaning mode, all or multiple detection points can be selected to be simultaneously purged and cleaned, or each detection point can be sequentially cleaned. In the former scheme, the cleaning efficiency is higher, but a larger gas flow is required; in the latter mode, a larger gas flow is not required, but the cleaning time will be longer. Those skilled in the art can flexibly adjust the connection or opening and closing of each distribution outlet of the gas distribution block according to the number of detection points to be cleaned and the time and cost requirements. It can also be known that the shape, size, position, number, etc. of the distribution outlet can be determined according to the purge gas input end of the optical module to be matched.

[0038] In order to realize the on-off or flow control of the purge gas, in some embodiments of the present disclosure, the gas distribution unit 2 further comprises a solenoid valve 23 arranged upstream of the gas distribution block 21 and downstream of the inlet 22. Here, the solenoid valve is arranged between the upstream of the gas distribution block and the downstream of the inlet, so that the purge gas introduced through the inlet first passes through the solenoid valve and then flows into the gas distribution block, and then is branched and introduced into the optical chamber of the optical module. The solenoid valve can thus be regarded as a kind of total switch. In this case, the inlet can be opened on the shell of the gas distribution unit on the side of the solenoid valve. The feature of this design is, for example, that the number of solenoid valves can be controlled, and thus the cost is relatively controllable, but the gas flow through the solenoid valve can be larger. In addition, the characteristics of using the solenoid valve itself also include being suitable for intelligent or automatic control, fine flow control, and easy maintenance. The control mode of the solenoid valve will be explained later in combination with Figure 6 and Figure 7 In addition, in terms of the form of the valve, stop valves, gate valves, ball valves, butterfly valves, etc. can also be considered, and the flow control can be independently or assistedly completed by the device for generating the purge gas.

[0039] In the embodiment shown in Figure 2 and Figure 3 , the gas distribution unit 2 further comprises a plurality of solenoid valves 23, which correspondingly cooperate with the distribution outlets 211, and the gas distribution block 21 has a distribution passage for branching the purge gas flowing through the inlet 22 to each solenoid valve 23.

[0040] It can be seen that in this embodiment, the electromagnetic valve corresponds to the distribution outlet one by one, and can more targetedly control the cleaning of each detection point, and the control mode is more flexible, and the electromagnetic valve can be opened in the whole purge mode or opened one by one in the single sequential purge mode. In the case that the pollution degree of each detection point is different, only the electromagnetic valve corresponding to the detection point needing cleaning can be opened, and the on-off or flow of each electromagnetic valve can be adjusted according to the pollution degree. It can also be seen that after the purge gas is introduced through the inlet, it first flows through the distribution passage of the gas distribution block, then flows through the electromagnetic valve, and then flows into the corresponding purge gas input end of the optical module through the distribution outlet.

[0041] Here, the electromagnetic valve can be arranged or formed in the lower part of the gas distribution unit, the gas distribution block can be arranged or formed in the upper part of the gas distribution unit, and the inlet can be arranged on one side of the gas distribution block in the upper part and open outward. Thus, in combination with Figure 3 With Figure 5 It can be seen that the purge gas flowing into the inlet is first downwardly flowed through the electromagnetic valve, then upwardly flowed through the gas distribution block again, and finally flowed into the optical cavity of the optical module, so that the gas distribution block has the functions of gas flow distribution and point-by-point guiding of the distributed gas flow. For this, it should be understood that the gas distribution block is designed to have a distribution passage arranged inside the gas distribution block and communicated with the inlet, and the distribution passage can extend in the longitudinal direction (length direction) of the gas distribution block, and the extension structure has a plurality of branch passages, each branch passage is communicated with a corresponding electromagnetic valve, and the corresponding electromagnetic valve is further communicated with a corresponding guide passage arranged in the gas distribution block, and the guide passage is communicated with the distribution outlet, and finally completes the gas delivery to the optical cavity of the optical module. In other embodiments, the electromagnetic valve can also be arranged in the upper part of the gas distribution unit, or in other words, the electromagnetic valve can be arranged between the gas distribution block and the optical module, and the similar technical effects can also be achieved in a similar manner.

[0042] It can be seen that the opening and closing of the electromagnetic valve can support two different modes of the gas monitor. When the electromagnetic valve is closed, the gas monitor is in a monitoring mode, which can be in a normal working state, and the gas flow can be detected by the flow sensor to be introduced below; when the electromagnetic valve is opened, the gas monitor is in a cleaning mode, and enters a shutdown state, the purge gas flows into the optical cavity through the inlet for cleaning work, and the flow sensor does not need to detect the gas flow at this time.

[0043] From Figure 1It can also be seen that the gas monitor comprises a differential pressure sensor 3 for sensing the pressure difference between the input end and the output end of the sampling gas inlet pipe of the gas monitor, and the output end is arranged in the optical chamber 11.

[0044] It should be noted that in one practical application, the sampling gas is introduced from the input end with a large flow rate, which can improve the response speed, and the small flow rate of the gas is respectively input to the sampling gas end (output end) of each optical module, wherein the small flow rate of the gas flow can reduce the pressure and stress of the paper tape to prevent the paper tape from being broken, and the small flow rate is sufficient for monitoring. In this case, the input end sensed by the differential pressure sensor can correspond to the input end of the small flow rate of the gas respectively transported to each detection point. In addition, the input end is also sometimes referred to as the front end of the inlet pipe, and the output end is also sometimes referred to as the rear end of the inlet pipe, wherein, Figure 1 、 Figure 4 and Figure 5 The rear end portion 7 of the sampling gas inlet pipe is schematically shown. It can also be understood that in other practical applications, the large flow rate of the gas can be respectively input to the sampling gas end (output end) of each optical module.

[0045] It should be understood that the basic principle of the differential pressure sensor is that, for example, in one embodiment of the differential pressure sensor, it is configured to convert the change of the pressure difference before and after into the change of the built-in pressure-sensitive element of the sensor, and then process and modulate the (weak) signal generated by the deformation of the pressure-sensitive element, or through analog-to-digital conversion and chip operation processing, finally output analog signal or digital signal. The differential pressure sensor can obtain the pressure difference between the input end and the output end, and then calculate the flow rate of the gas.

[0046] Since the output end is located in the optical chamber, the environmental conditions (such as pollutants) in the optical chamber will affect the pressure of the output end, and then affect the flow rate, causing flow rate fluctuations. Therefore, the pollution situation inside the optical chamber can be reflected by the flow rate fluctuations obtained directly or indirectly by the differential pressure sensor, and cleaning can be performed when needed.

[0047] It can also be understood that the number of differential pressure sensors is set to be consistent with the number of detection points of the optical module, so that each differential pressure sensor can detect the environmental conditions of each detection point, and the corresponding electromagnetic valve can be opened as needed for cleaning work. In addition, these differential pressure sensors can be arranged in alignment on the printed circuit board 5, so that the sensor group composed of these differential pressure sensors and the entire gas monitor have high integration and compactness, and the differential pressure sensors can be conveniently managed and maintained.

[0048] It is also possible to consider using various flow sensors such as vortex flow sensors, turbine flow sensors, electromagnetic flow sensors, ultrasonic flow sensors, thermal flow sensors, etc. in addition to the differential pressure sensor. Therefore, in general, in some embodiments of the present disclosure, the gas monitor can include a flow sensor for sensing the sampling gas flow of the sampling gas inlet pipe of the gas monitor, and the above technical effects can be achieved. Here, the flow sensor can achieve two functions. On the one hand, it is used for monitoring the state of the instrument, such as monitoring the gas flow through the optical chamber of the optical module, ensuring the gas flow value (e.g. 200cc), and keeping the flow stable. On the other hand, the fluctuation rate of the flow is monitored by the flow sensor as one of the criteria for judging the pollution inside the optical chamber, and cleaning is performed when necessary.

[0049] However, it should also be understood that the differential pressure sensor is more targeted because one end can directly measure the gas pressure at the output end in the optical chamber. In addition, the differential pressure sensor itself also has characteristics including high precision, wide measurement range, high stability, fast response, high temperature resistance, corrosion resistance, and suitability for miniaturization and integration, etc.

[0050] In combination with Figure 4 and Figure 5 wherein, Figure 4 shows a cross-sectional view of the gas monitor of Figure 1 in a monitoring mode; and Figure 5 shows a cross-sectional view of the gas monitor of Figure 1 in a cleaning mode.

[0051] The differential pressure sensor 3 has a first sensing end 31 and a second sensing end 32, the first sensing end 31 is connected with the sensing docking end 212 of the gas distribution block 21, the sensing docking end 212 communicates with the optical chamber 11 via the distribution outlet 211 and the purge gas input end 12, and the second sensing end 212 is used to sense the gas pressure of the input end of the sampling gas inlet pipe of the gas monitor. Wherein, the distribution outlet and the purge gas input end can be connected by the first pipeline 4, and similarly, the first sensing end and the sensing docking end can also be connected by the second pipeline 6.

[0052] The technical solution ingeniously integrates the sensing function of the differential pressure sensor and the cleaning function of the purge gas passing through the gas distribution unit into the optical module, so that the gas distribution block has such a dual function. Specifically, since the sensing docking end is in communication with the optical chamber through the distribution outlet and the purge gas input end, and the sensing docking end is connected with the first sensing end of the differential pressure sensor, the differential pressure sensor can remotely sense the air pressure in the internal chamber of the optical module, so that the differential pressure sensor can be arranged separately, for example, on a printed circuit board, and such a design form does not affect the flow process of the purge gas or the sampling process of the sampling gas in the normal working of the gas monitor. Even in the cleaning mode, the purge gas in the working state occupies the distribution outlet of the gas distribution unit, the purge gas input end of the optical module and enters the internal optical chamber, but at this time, since it is in the cleaning mode, the flow sensor or the differential pressure sensor does not need to play a sensing function at this time, and can be tested after cleaning. In other embodiments, the first sensing end of the differential pressure sensor can be connected to the chamber of the optical module in other ways, and the arrangement position and the situation of the differential pressure sensor can be adjusted adaptively. For example, the differential pressure sensor is arranged on the gas distribution unit or the optical module, and the first sensing end of the differential pressure sensor is connected to the distribution outlet or the purge gas input end, or a separate through hole is formed in the chamber of the optical module to connect the first sensing end of the differential pressure sensor, and the like.

[0053] In addition to using the flow of the sampling gas as a standard for judging whether the optical chamber of the optical module is contaminated, the judgment can also be made by means of light signals. Specifically, in some embodiments of the present disclosure, the gas monitor further comprises a light intensity sensor for sensing the intensity of the light receiving signal of the optical chamber 11.

[0054] According to the technical solution, if contamination such as dust, paper scraps or impurities accumulates inside the optical chamber, these contaminants can absorb or scatter part of the light, causing the light signal intensity received by the light intensity sensor to change, for example, to become smaller or larger (for example, dust and other contaminants falling on the paper strip). Therefore, by detecting the signal intensity output by the light intensity sensor and comparing it with the signal intensity in the normal state, it can be inferred whether there is contamination inside the optical chamber. For this purpose, the light intensity sensor is arranged in the optical chamber and can collect the light intensity of the spots on the chemical paper strip. This method provides an effective technical means for contamination detection of the optical chamber. The characteristics of the light intensity sensor include high precision, high sensitivity, wide measurement range, good stability, fast response, non-contact and low power consumption, etc.

[0055] It is also understandable that, as one embodiment of a light intensity sensor, it can utilize a photosensitive element to convert light signals into electrical signals. The photosensitive element, as the core component, can be a photodiode or a phototransistor. When light shines on the photosensitive element, it induces a photocurrent, the magnitude of which is proportional to the light intensity. Therefore, by measuring the magnitude of the photocurrent, the light intensity can be calculated. In addition, in other embodiments, silicon photovoltaic cells or CCD chips can also be used as photosensitive elements to measure light intensity. When the light source in the optical cavity of the optical module is infrared light, thermistor sensors, thermocouple sensors, pyroelectric sensors, and photoconductive sensors can be considered as light intensity sensors.

[0056] It should also be understood that the discharge pathways for contaminants carried by the purge gas can be designed to ensure their smooth discharge without affecting the components of the gas monitor. This can be combined with... Figure 5 The arrows can be used to interpret this. Exemplarily, the optical module of the gas monitor is divided into a first sub-module 13 located at the top and a second sub-module 14 located at the bottom, with the optical chamber located in the first sub-module. In normal operating mode, these two sub-modules are interconnected; in cleaning mode, the movable part 141 of the second sub-module can move away from the first sub-module, creating a gap between the two sub-modules to facilitate the side discharge of purge gas along with contaminants. Simultaneously, the chemical paper strip located therein also serves to prevent exhaust gas from flowing into the second sub-module. Subsequently, the movable part can be reset by, for example, a return spring 142 located in the second sub-module, and reconnected to the first sub-module. In some other embodiments, the second sub-module may have an internal discharge channel to facilitate the discharge of purge gas and contaminants to a predetermined location.

[0057] Combination Figure 6 and Figure 7 ,in, Figure 6 A flowchart of a cleaning method for a gas monitor according to this disclosure is shown; and Figure 7 A flowchart of a testing method for a gas monitor according to this disclosure is shown.

[0058] The gas monitor also includes a controller configured to determine whether to introduce the purging gas based on the cleaning time of the gas monitor, the flow rate fluctuation of the sampling gas inlet pipe of the gas monitor, or the intensity fluctuation of the light received signal in the optical chamber 11.

[0059] Thus, as mentioned before, the cleaning can be determined according to the expiration of the cleaning interval, the flow rate variation, the light intensity variation or some operation such as replacing the paper tape. Accordingly, a cleaning method according to the present disclosure comprises the following steps: S1: in response to 7 days before the expiration of the cleaning interval, the flow rate fluctuation rate of the sampling gas inlet pipe being greater than or equal to 30%, the intensity fluctuation rate of the light receiving signal being greater than or equal to 30%, or replacing the paper tape for the optical chamber, entering step S2; S2: outputting a reminder signal, entering step S3, wherein the reminder signal can be a sound signal, an image signal, a text signal or a combination thereof, etc., to remind the user or the maintenance personnel to clean the optical chamber; S3: in response to the relevant personnel confirming to enter the cleaning mode, entering step S4; S4: starting to clean the optical chamber, entering step S5, wherein the compressed gas is introduced through the inlet by the device for generating compressed gas and finally enters the optical chamber of the optical module in the manner described before, in the process, the gas monitor stops the normal working mode, and the electromagnetic valve is controlled to open at the expected opening degree to input the compressed air into the optical chamber, at this time, as mentioned before, the differential pressure sensor can not detect the differential pressure; S5: after the cleaning is completed, resetting the cleaning time, for example, setting its value to 60 days, and entering the countdown state, when its value is less than 7 days, the method can be triggered again. At this time, the electromagnetic valve is in the closed state, the purge gas does not flow through the distribution outlet and the purge gas input end, so that the differential pressure sensor can be in the state of detecting the pressure inside the optical chamber. It can also be understood that the fluctuation rate herein covers both upward fluctuation and downward fluctuation. It is also possible to perform the cleaning step in response to a user manual control instruction. The advantage of cleaning when replacing the paper tape is that the replacement of the paper tape requires shutdown, so that the replacement time of the paper tape can be used to perform the purge operation, the time utilization rate is high and the online time is not affected, thereby the use time of the gas detector before the next cleaning can be improved.

[0060] It is also possible to provide a verification mechanism after the cleaning is completed to verify whether the previous cleaning step is performed in place or meets the requirements. Specifically, a verification method according to the present disclosure comprises the following steps: P1: in response to the flow rate fluctuation rate of the sampling gas inlet pipe being less than 30%, entering step P2; P2: in response to the intensity fluctuation rate of the light receiving signal being less than 30%, entering step P3; P3: outputting a signal that the cleaning is completed. Optionally, at this time, the cleaning time is reset, for example, setting its value to 60 days. Alternatively, in steps P1 and P2, if the indicators after the cleaning still do not meet the requirements, a prompt information can be sent to the relevant personnel to contact the supplier to seek professional assistance. The cleaning method and the verification method of the present disclosure can be performed by the controller.

[0061] It should be understood that the naming of various method steps herein is merely for the convenience of distinguishing and referring to the method steps, and does not represent the necessity of the sequence of the method steps (unless otherwise specified), which can be adjusted according to actual conditions or even executed simultaneously. For example, step S2 can be cancelled, steps P1 and P2 can be executed simultaneously, and there is no mandatory sequence between the two, and the like.

[0062] Regarding the input mode of the purge gas, it should be noted that the purge gas can be continuously blown into the optical chamber, or can be blown into the optical chamber in a pulsed or intermittent manner. In the former scheme, since the purge gas is always input, the cleaning process is stable and easy to control, and the cleaning efficiency can be guaranteed; in the latter scheme, since the purge gas is input intermittently, for example, once every second, the environmental state in the optical chamber will change during the interval, so that the pollutants change position for a period of time to increase the probability of being blown away next time, which has better cleaning effect for some pollutants in a tricky position, and can also avoid the situation that the pollutants are always blown against the edge and cannot be blown out in the continuous blowing mode.

[0063] Regarding the configuration mode of the controller, in some embodiments of the present disclosure, the controller is integrated into the MCU (Microcontroller Unit, sometimes also referred to as micro control unit) of the gas monitor. This integrated design has better compatibility, does not increase the burden of additional components for the gas monitor, does not increase the structural complexity, has good reliability, and the cost is controllable. In addition, the controller can utilize the resources (such as computing power) of the MCU to realize its own functions, so as to ensure the performance of the controller.

[0064] According to another aspect of the present disclosure, the present disclosure also relates to a gas monitoring system, wherein the gas monitoring system comprises any of the above-mentioned gas monitors and an industrial computer. Thus, the various embodiments of the gas monitoring system of the present disclosure and the various technical effects that can be achieved can inherit the embodiments of the gas monitor and the corresponding technical effects, which will not be repeated here.

[0065] It should be understood that the industrial computer of the gas monitoring system can be used to uniformly manage and control one or more gas monitors, in which case, the various controllers of the present disclosure can also be considered to be built into the industrial computer, which is convenient for centralized operation and management.

[0066] As mentioned before, the purge gas, e.g. compressed gas, for input to the access port can be generated by an external device, which can be permanently connected to the access port and switched on when needed, or which can be connected to the access port only when needed. Thus, the gas monitoring system further comprises as such external device an air compressor, which can be connected to the access port 22, for generating the purge gas. This technical solution allows for a convenient and efficient access to the purge gas as input source when needed for cleaning the optical chamber, reducing the preparation time. The air compressor should be understood in a broad sense as any device capable of generating compressed air, which for example can also encompass steel bottles, compressed air guns and the like.

[0067] It is to be understood that all the above preferred embodiments are exemplary and not restrictive, and that various modifications or variations to the specific embodiments described above, which a person skilled in the art can make under the concept of the present disclosure, shall be within the legal protection scope of the present disclosure.

Claims

1. A gas monitor comprising: The gas monitor comprises an optical module (1) and a gas distribution unit (2), the gas distribution unit (2) comprises a gas distribution block (21) and is provided with an inlet (22) for introducing a purge gas, the purge gas can be distributed through the gas distribution block (21) and flow to an optical cavity (11) of the optical module (1) to purge the contaminants in the optical cavity (11).

2. The gas monitor of claim 1, wherein, The gas distribution block (21) is provided with a plurality of distribution outlets (211), each distribution outlet (211) is connected with a purge gas input end (12) of the optical module (1), and each purge gas input end (12) is communicated with the optical cavity (11).

3. The gas monitor of claim 2, wherein, The gas distribution unit (2) further comprises a solenoid valve (23), which is arranged upstream of the gas distribution block (21) and downstream of the inlet (22).

4. The gas monitor of claim 2, wherein, The gas distribution unit (2) further comprises a plurality of solenoid valves (23), which correspond to the distribution outlets (211) one by one, and the gas distribution block (21) has a distribution passage for distributing the purge gas flowing through the inlet (22) to each solenoid valve (23).

5. The gas monitor of claim 2, wherein, The gas monitor comprises a flow sensor for sensing the flow of a sampling gas of a sampling gas inlet pipe of the gas monitor.

6. The gas monitor of claim 5, wherein, The flow sensor is a differential pressure sensor (3) for sensing the pressure difference between the input end and the output end of the sampling gas inlet pipe of the gas monitor, and the output end is arranged in the optical cavity (11).

7. The gas monitor of claim 6, wherein, The differential pressure sensor (3) has a first sensing end (31) and a second sensing end (32), the first sensing end (31) is connected with a sensing docking end (212) of the gas distribution block (21), the sensing docking end (212) is communicated with the optical cavity (11) through the distribution outlet (211), the purge gas input end (12), and the second sensing end (32) is used for sensing the gas pressure of the input end of the sampling gas inlet pipe of the gas monitor.

8. The gas monitor of claim 1, wherein, The gas monitor further comprises a light intensity sensor for sensing the intensity of a light receiving signal of the optical cavity (11).

9. The gas monitor of claim 1, wherein, The gas monitor further comprises a controller configured to determine whether to perform the introduction of the purge gas based on the cleaning interval expiration time of the gas monitor, the flow fluctuation rate of the sampling gas inlet pipe of the gas monitor, the intensity fluctuation rate of the light receiving signal of the optical cavity (11), the replacement of a paper tape for the optical cavity (11), or a user instruction.

10. The gas monitor of claim 9, wherein, The controller is integrated in a single-chip microcomputer of the gas monitor.

11. A gas monitoring system characterized by, The gas monitoring system comprises the gas monitor according to any one of claims 1 to 10 and an industrial computer.

12. The gas monitoring system of claim 11, wherein, The gas monitoring system further comprises an air compressor, which can be connected to the inlet (22) and used to generate the purge gas.

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