TWI804391B - Gas sensing module - Google Patents

Abstract

A gas sensing module includes a base, a gas sensor, and a light emitting unit. The base comprises a receiving space and two openings which are on two opposite ends of the receiving space and in spatial communication with the receiving space. The gas sensor is deposited in the receiving space, and is applied for sensing the gas which passes through the openings and the receiving space. The gas sensor comprises a substrate and a sensor which is deposited on the substrate. The substrate is made of high thermally conductive material. The light emitting unit comprises a UV light emitting member which is deposited on the substrate near the gas sensor.

Description

Gas Sensing Module

The present invention relates to a sensing module, in particular to a gas sensing module.

The technology of the gas sensing module has been widely used in the fields of people's livelihood and industry. Its sensing principle includes electrochemistry, infrared light, catalytic combustion and semiconductor-type sensing mechanism. An existing gas sensing module uses a semiconductor-type sensing mechanism. The surface of the sensor adsorbs gas molecules as electron donors or acceptors. Therefore, its sensing mechanism includes hole-induced conduction and electron-induced conduction, which will result in a change in the output resistance signal of the sensing element. Change, the change of resistance is a function of gas concentration, use this relationship to detect gas concentration. This sensing principle has excellent reliability and recycling characteristics. However, it takes up to 20-30 minutes for the sensor to completely desorb the gas after use, which seriously affects the restart time of the sensor, so there is still a problem. room for improvement.

Therefore, one object of the present invention is to provide a gas sensing module capable of solving at least one of the above problems.

Therefore, the gas sensing module of the present invention includes a base, including an accommodating space and two openings located at opposite ends and communicating with the accommodating space; a gas sensor is arranged in the accommodating space, the The gas sensor includes a substrate and a sensing element arranged on the substrate; and a light emitting unit including at least one UV light emitting element arranged on the substrate and adjacent to the sensing element.

In some embodiments, the base further includes a reflective plate disposed in the accommodating space, and the ultraviolet light emitted by the UV light-emitting element can be concentrated and irradiated to the sensing element through the reflective plate.

In some embodiments, the base further includes a bottom plate and an arched top cover, and the bottom plate and the top cover define the accommodating space and the openings.

In some embodiments, the bottom plate is shaped like a slot and two grooves on both sides of the slot, the slot is used for the substrate of the gas sensor, and the grooves are used for the reflection plate.

In some implementation aspects, the reflective plate is arched and has a reflective surface facing the light emitting unit, and the reflective surface is a curved surface.

In some implementation aspects, the substrate is coated with thermally conductive glue.

In some embodiments, the wavelength of ultraviolet light emitted by the UV light-emitting element is between 200-400 nm.

In some embodiments, the light emitting unit includes two UV light emitting elements, which are respectively arranged on two sides of the sensing element.

The present invention has at least the following effects: because the UV light-emitting element of the light-emitting unit is arranged on the substrate and adjacent to the sensing element, and the substrate is made of a high thermal conductivity material, the heat generated by the UV light-emitting element is used for The sensing element is heated to increase the temperature of the sensing element to accelerate the desorption rate of the gas from the sensing element, thereby shortening the recovery time of the sensing element so that it can be used again, effectively improving the use efficiency. The ultraviolet light of the UV light-emitting element irradiating the sensing element can also accelerate the desorption rate of the gas from the sensing element, so as to shorten the recovery time of the sensing element.

Referring to FIG. 1 and FIG. 2 , an embodiment of a gas sensing module 10 of the present invention is suitable for sensing household or industrial waste gases, such as CO, CO2, NO, and NO2. The gas sensing module 10 includes a base 1 , a gas sensor 2 and a light emitting unit 3 .

Referring to FIGS. 1 to 3 , the base 1 includes a bottom plate 11 , an arched top cover 12 and a reflector 15 disposed on the bottom plate 11 . The bottom plate 11 and the top cover 12 define an accommodating space 13 and two openings 14 located at opposite ends and communicating with the accommodating space 13 . The bottom plate 11 forms a slot 111 and two grooves 112 on both sides of the slot 111 , the slot 111 is used for the gas sensor 2 , and the grooves 112 are used for the reflection plate 15 . The reflecting plate 15 is arched and located in the accommodating space 13 , and has a reflecting surface 151 facing the bottom plate 11 , and the reflecting surface 151 is a curved surface.

Referring to FIGS. 2 to 4 , the gas sensor 2 is disposed in the accommodating space 13 for detecting the gas passing through the openings 14 and the accommodating space 13 . The gas sensor 2 includes a substrate 21 and a sensing element 22 disposed on the substrate 21. The substrate 21 is made of a material with high thermal conductivity, such as aluminum metal, but not limited thereto. The sensing element 22 Graphene is used, but it is not limited thereto. The substrate 21 is coated with a thermally conductive adhesive 23 to further increase thermal conductivity. The gas sensor 2 used in this embodiment adopts a semiconductor-type sensing mechanism, but it is not limited thereto. Selective adsorption, the surface of the sensing element 22 adsorbs gas molecules as electron donors or acceptors, so its sensing mechanism includes hole-induced conduction and electron-induced conduction, resulting in a change in the output resistance signal of the sensing element 22, The change in resistance is a function of gas concentration, and this relationship can be used to detect gas concentration. The light emitting unit 3 includes two UV light emitting elements 31 disposed on the substrate 21 and adjacent to the sensing element 22 , specifically, the UV light emitting elements 31 are respectively disposed on two sides of the sensing element 22 . Each UV light-emitting element 31 is a UV LED, which emits ultraviolet light with a wavelength of 200-400nm. The heat energy generated by the operation of the UV light emitting element 31 is used to heat the sensing element 22, increasing the temperature of the sensing element 22 to accelerate the rate of desorption of gas from the sensing element 22, thereby shortening the recovery time of the sensing element 22 and can be used again. Moreover, the UV luminous element 31 can be arched and positioned above the UV luminous element 31 by the reflecting plate 15, and the ultraviolet light emitted by the UV luminous element 31 can be reflected and concentrated on the sensing element 22 through the reflective surface 151. The desorption rate of the gas from the sensing element 22 is accelerated to shorten the recovery time of the sensing element 22 . Wherein, the number of UV light emitting elements 31 is not limited to two, and may be other numbers in other embodiments, as long as at least one is adjacent to the sensing element 22 . The reflecting plate 15 is not limited to being arched, and the reflecting surface 151 is also not limited to a curved surface, as long as the characteristic structure that can reflect the ultraviolet light emitted by the UV light emitting element 31 and gather it on the sensing element 22 is applicable.

Referring to FIG. 5 , it illustrates the temperature raising effect of the UV light emitting element 31 on the sensing element 22 under different operating powers. The greater the power of the UV light emitting element 31 , the better the temperature raising effect of the sensing element 22 . Referring next to Fig. 6, it illustrates that the gas sensor 2 is in the recovery stage (the condition that the reflector 15 is not installed), and the heat energy generated by the operation of the UV light emitting element 31 is used to heat the gas sensor 2, thereby observing The temperature of the gas sensor 2 increases to reduce the recovery time. The higher the power of the UV light-emitting element 31 , the higher the temperature of the gas sensor 2 is. According to the experimental results, the higher the temperature of the gas sensor 2 is, the faster the desorption rate of the gas is, thereby shortening the recovery time of the sensor. Among them, NO ON means that the NO gas is started to be detected by the gas sensor 2, air means that the detection is completed, and the time interval until the next NO ON means the recovery time. Referring to FIG. 7 again, it illustrates the influence of whether the reflector 15 is provided on the recovery time of the gas sensor 2 . From the comparison of the experimental results, it is known that when the power of the UV light emitting element 31 is increased from 1.15W to 3.6W, the recovery time is shortened from 896 seconds to 308 seconds under the condition that the temperature of the gas sensor 2 is only increased but the reflector 15 is not installed. seconds, and when the reflecting plate 15 is installed, the recovery time is shortened from 896 seconds to about 110 seconds, and the shortening range is greatly increased.

To sum up, the gas sensing module 10 of the present invention is provided with the UV light-emitting element 31 of the light-emitting unit 3 on the substrate 21 and adjacent to the sensing element 22, and the substrate 21 is made of a high thermal conductivity material, The heat energy generated by the operation of the UV light-emitting element 31 is used to heat the sensing element 22, increasing the temperature of the sensing element 22 to accelerate the desorption rate of the gas from the sensing element 22, thereby shortening the recovery of the sensing element 22 Time can be used again, effectively improving the efficiency of use. Moreover, the UV luminous element 31 can be arched and positioned above the UV luminous element 31 by the reflecting plate 15, and the ultraviolet light emitted by the UV luminous element 31 can be reflected and concentrated on the sensing element 22 through the reflective surface 151. The desorption rate of the gas from the sensing element 22 is accelerated to shorten the recovery time of the sensing element 22, so the purpose of the present invention can indeed be achieved.

But what is described above is only an embodiment of the present invention, and should not limit the scope of the present invention. All simple equivalent changes and modifications made according to the patent scope of the present invention and the content of the patent specification are still within the scope of the present invention. Within the scope covered by the patent of the present invention.

10: Gas sensing module 1: Base 11: Bottom plate 111: card slot 112: Groove 12: Top cover 13:Accommodating space 14: opening 15: reflector 151: reflective surface 2: Gas sensor 21: Substrate 22: Sensor 23: thermal adhesive 3: Lighting unit 31:UV light emitting parts

Other features and effects of the present invention will be clearly presented in the implementation manner with reference to the drawings, wherein: Fig. 1 is a perspective view of an embodiment of the gas sensing module of the present invention; Fig. 2 is a three-dimensional exploded view of this embodiment; Fig. 3 is a front view of this embodiment; Fig. 4 is a part of the top view of this embodiment, wherein a top cover and a reflection plate of a base are omitted; Fig. 5 is a broken line diagram illustrating the effect of the UV light-emitting element on the temperature increase of the sensing element under different operating powers; Figure 6 is a broken line diagram illustrating that when the gas sensor is in the recovery stage (the condition without a reflector), the heat energy generated by the operation of the UV light-emitting element is used to heat the sensor, thereby observing the gas sensor The effect of increasing temperature on reducing recovery time; and FIG. 7 is a broken line diagram illustrating the influence of whether the reflector is provided on the recovery time of the gas sensor.

10: Gas sensing module

1: Base

11: Bottom plate

111: card slot

112: Groove

12: Top cover

13:Accommodating space

14: opening

15: reflector

2: Gas sensor

Claims (7)

A gas sensing module, comprising: a base, including an accommodating space and two openings located at opposite ends and communicating with the accommodating space; a gas sensor, arranged in the accommodating space, for To detect the gas passing through the openings and the accommodating space, the gas sensor includes a substrate and a sensing element arranged on the substrate, the substrate is made of high thermal conductivity material; and a light emitting unit includes at least one The UV light-emitting element on the substrate and adjacent to the sensing element; wherein, the base also includes a reflective plate arranged in the accommodating space, and the ultraviolet light emitted by the UV light-emitting element can be concentrated and irradiated to the sensor through the reflective plate. test piece. The gas sensing module as claimed in claim 1, wherein the base further includes a bottom plate and an arched top cover, the bottom plate and the top cover define the accommodating space and the openings. The gas sensing module according to claim 2, wherein the base plate forms a slot and two grooves on both sides of the slot, the slots are used for the substrate of the gas sensor, and the grooves A groove is provided for the reflection plate. The gas sensing module as claimed in claim 2, wherein the reflection plate is arched and has a reflection surface facing the light emitting unit, and the reflection surface is a curved surface. The gas sensing module as claimed in item 1, wherein the substrate is coated with thermal conductive glue. The gas sensing module as claimed in item 1, wherein the ultraviolet light emitted by the UV light-emitting element has a wavelength of 200-400nm. The gas sensing module as claimed in item 1, wherein the light emitting unit includes two UV light emitting elements, which are respectively arranged on two sides of the sensing element.

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