Electrochemical carbon monoxide sensor

Abstract

The utility model relates to an electrochemical carbon monoxide sensor which comprises an outer shell, a sealing ring, an upper shell flange wing contained in the sealing ring, an anode supporting sheet and a rubber layer on the lower portion of the sealing ring, the sealing ring is pressed downwards on the upper side of the sealing ring, so that the anode supporting sheet moves downwards, and a mechanical power structure for pressing a membrane electrode unit is formed. The upper surface of the anode supporting piece is connected with the upper shell flange wing, the lower surface of the anode supporting piece is connected with the lower rubber layer of the sealing ring, the height of the stepped boss of the disc-shaped anode supporting piece is smaller than the thickness of the lower rubber layer of the sealing ring, and the difference height ranges from 0.1 mm to 0.5 mm. The stepped boss of the disc-shaped anode supporting sheet moves downwards to be in contact with the anode collector membrane positioning sheet and then forms a rigid limiting structure with the cathode supporting sheet, and the total compression rate of the membrane electrode unit through the rigid limiting structure is 10-30%. According to the utility model, the uniform shrinkage of the anode current collecting membrane, the membrane electrode and the cathode current collecting membrane can be ensured, the dispersion of electrical properties is reduced, and the long service life is realized.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the sensor technical field, especially relate to a kind of electrochemical carbon monoxide sensor. BACKGROUND

[0002] Carbon monoxide gas is characterized by being toxic and colorless and odorless, which cannot be found by human senses, and needs to rely on a carbon monoxide sensor. An electrochemical gas sensor is a detector that measures the current generated by the oxidation or reduction of the measured gas at the electrode to obtain the concentration of the object gas. The carbon monoxide gas sensor is used with an alarm, which is the core detection element in the alarm, and is based on the principle of constant potential electrolysis. When carbon monoxide diffuses to the gas sensor, an electric current is generated at the output end, which is provided to the sampling circuit in the alarm, and plays a role in converting chemical energy into electrical energy. When the gas concentration changes, the output current of the gas sensor also changes in direct proportion, which is converted and amplified by the intermediate circuit of the alarm to drive different execution devices to complete the detection and alarm functions of sound, light and electricity, and together with the corresponding control device, an environmental detection or monitoring alarm system is formed. The conventional electrochemical carbon monoxide gas sensor mainly includes a gas inlet, a membrane electrode reaction unit and a shell, the gas inlet is a part through which the gas (e.g. carbon monoxide) enters from the outside, including an anode terminal, an upper shell, a degassing filter part and a sealing ring. The membrane electrode reaction part includes an anode support sheet, an anode current collector film guide film, an anode current collector film, a membrane electrode, a cathode current collector film, a cathode current collector film guide film and a cathode support sheet. The shell includes a reaction space part, a water space part and a negative electrode terminal, the upper edge of the reaction space part is provided with a curling part, and a space separator jaw is arranged between the reaction space part and the water space part. The principle of detecting carbon monoxide gas by the electrochemical carbon monoxide gas sensor: the carbon monoxide gas introduced through the anode gas inlet of the anode support sheet passes through the anode current collector film and undergoes oxidation reaction on the anode reaction surface of the membrane electrode, and the carbon monoxide is oxidized into carbon dioxide. At this time, hydrogen ions are generated by the decomposition of water molecules. The generated hydrogen ions pass through the cathode gas inlet of the cathode support sheet and the cathode current collector film, and generate water (H2O) and oxidation reaction: CO + H2O ⇒ CO2 + 2H+ + 2e- through the oxidation-reduction reaction: 1 / 2O2+ 2H++ 2e- ⇒ H2O. In this way, the electrochemical carbon monoxide gas sensor measures the gas concentration of carbon monoxide by using the oxidation-reduction reaction between the anode reaction surface and the cathode reaction surface and the current intensity proportional to the amount of carbon monoxide oxidation reaction. The patent document with the authorization announcement number CN 217033834 U discloses a carbon monoxide sensor.The carbon monoxide sensor comprises: a main shell; a lower support plate arranged in the main shell, the lower support plate divides the main shell into a water containing cavity below the lower support plate and a reaction cavity above the lower support plate, and the water containing cavity has water therein; a multilayer membrane assembly arranged in the reaction cavity on the lower support plate; and a cover assembly on the multilayer membrane assembly, the cover assembly comprises: a top cover, an upper support plate, a filter body between the top cover and the upper support plate, and a sealing ring wrapped outside the top cover and the upper support plate; wherein a curled edge portion is formed at the top of the main shell, the curled edge portion compresses the sealing ring of the cover assembly and the multilayer membrane assembly towards the lower support plate.

[0003] The carbon monoxide sensors on the market have basically the same structure, but the production processes are different. According to the principle of the carbon monoxide gas sensor detecting carbon monoxide gas, the deformation thickness of the anode current collecting film, the cathode current collecting film and the membrane electrode after processing is a major factor affecting the dispersion of the electrical properties of the sensor. The conventional process is to control the deformation thickness of the anode current collecting film, the cathode current collecting film and the membrane electrode by the thickness change of the lower end of the sealing ring when the curled edge is formed at the top of the main shell. Since the elastic deformation amount of the lower end of the sealing ring cannot be accurately controlled, the deformation thickness of the anode current collecting film, the cathode current collecting film and the membrane electrode is inconsistent, and the dispersion of the electrical properties of the produced sensor is inconsistent. The built-in water solute in the existing product gradually evaporates through the cathode current collecting film and the anode current collecting film, and the water loss speed is relatively fast, resulting in a relatively short service life.

[0004] The industry urgently needs to find a method to minimize the dispersion of electrical properties and prolong the service life while maintaining the manufacturing cost. Content of the utility model

[0005] The utility model aims at overcoming the technical defects of the above-mentioned technology, and provides an electrochemical carbon monoxide sensor, which can ensure the consistency of the shrinkage of the anode current collecting film, the membrane electrode and the cathode current collecting film of the membrane electrode reaction part by increasing the rigid limiting structure inside the sensor, maximize the dispersion of the electrical properties, and slow down the water evaporation speed through the secondary sealing between the membrane electrodes, thereby achieving a longer service life.

[0006] The utility model discloses a technical scheme that realizes the above-mentioned purpose: an electrochemical carbon monoxide sensor, comprising a shell, the shell is divided into reaction space and water containing space through necking, the shell is curved along the central direction at the top of reaction space, has the edge curling portion of the upper surface of containing sealing ring to pressurize downward, the sealing ring is sealedly connected with upper shell, the inner chamber of upper shell is sequentially provided with first waterproof dustproof filter sheet, activated carbon layer, second waterproof dustproof filter sheet, filter sheet support sheet, anode support sheet, anode current collecting film positioning sheet and cathode support sheet from top to bottom, the positioning hole of anode current collecting film positioning sheet is sequentially provided with anode current collecting film, membrane electrode and cathode current collecting film, three layers of anode current collecting film, membrane electrode and cathode current collecting film constitute membrane electrode unit, the thickness of anode current collecting film positioning sheet is less than the thickness of anode current collecting film, the thickness of the laminated sheet of cathode current collecting film and membrane electrode is greater than the thickness of cathode current collecting film positioning sheet, form the lower space between the upper surface of cathode current collecting film positioning sheet and the lower surface of anode current collecting film positioning sheet, and the upper space between the upper surface of anode current collecting film positioning sheet and the lower surface of anode support sheet, the flange wing of upper shell, anode support sheet and sealing ring lower rubber layer contained by sealing ring, sealing ring is pressed down its upper side, make anode support sheet move downward, constitute the mechanical power structure of compact membrane electrode unit, the cross section shape of anode support sheet is circular disc with step platform, the upper surface of circular disc anode support sheet outer edge is connected with upper shell flange wing, its lower surface is connected with sealing ring lower rubber layer, the height of step boss of circular disc anode support sheet is less than the thickness of sealing ring lower rubber layer, the difference height is 0.1mm-0.5mm, after circular disc anode support sheet step boss moves down and touches with anode current collecting film positioning sheet, form rigid limiting structure with cathode support sheet, the total compression rate of membrane electrode unit through rigid limiting structure is 10%-30%;The cross section shape of cathode support sheet is circular disc with step platform, the circular ring anode current collecting film positioning sheet is arranged between the step boss bottom of anode support sheet and the step concave platform of cathode support sheet, the inner diameter of circular ring anode current collecting film positioning sheet is less than the outer diameter of membrane electrode and cathode current collecting film, the inner circle of anode current collecting film positioning sheet is on the upper surface of membrane electrode, forms the sealed connection of shell-sealing ring-anode current collecting film positioning sheet-membrane electrode.

[0007] Preferably, the cathode support sheet is circular, and the cathode current collecting film positioning sheet and the anode current collecting film positioning sheet are arranged between the cathode support sheet and the anode support sheet, the center hole of the cathode current collecting film positioning sheet is provided with the membrane electrode and the cathode current collecting film, and the cathode current collecting film positioning sheet center hole is provided with a cathode current collecting film containing space between the membrane electrode and the cathode current collecting film, which can accommodate the compression deformation amount of the membrane electrode and the cathode current collecting film.

[0008] Preferably, the cross section shape of the sealing ring is inverted "U" shape, the ratio of the upper thickness to the lower thickness is 3:1~6:1, the upper thickness is 1.5~1.8mm, and the lower thickness is 0.3~0.6mm.

[0009] Preferably, the activated carbon layer adopts granular activated carbon or fibrous activated carbon cotton.

[0010] Preferably, the shell has a diameter of 14-17 mm, a height of 20-50 mm, and a thickness of 0.2-0.3 mm, and is made of stainless steel.

[0011] Preferably, the anode support sheet has a diameter of 11-16 mm and a thickness of 0.6-1.0 mm, and is made of stainless steel.

[0012] Preferably, the anode current collector film positioning sheet has a thickness of 0.25-0.45 mm and is made of PET, PP or PE.

[0013] Preferably, the anode current collector film and the cathode current collector film have a thickness of 0.35-0.55 mm respectively, and are made of PTFE conductive gas diffusion membrane material.

[0014] Preferably, the membrane electrode has a thickness of 0.1-0.2 mm and is made of MEA membrane electrode material.

[0015] Preferably, the cathode support sheet has an outer diameter of 11-16 mm and a thickness of 0.6-1.0 mm, and is made of stainless steel.

[0016] Beneficial effects: compared with the prior art, the improved sensor of the utility model is packaged, the anode / cathode current collector film and the membrane electrode have accurate final compression height, even under different flanging pressures, the consistency of the compression thickness can be ensured, that is, the purpose of reducing the electric characteristic dispersion between sensor products can be achieved. The shrinkage of the anode current collector film, the membrane electrode and the cathode current collector film can be homogenized, and the dispersion of electric performance is reduced. Not only the consistency of the product is improved, but also the loss of moisture is reduced through the secondary sealing mode inside the sensor, and the service life is effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic view of the appearance of an electrochemical carbon monoxide sensor of the utility model;

[0018] Figure 2 is an exploded view of the electrochemical carbon monoxide sensor of the utility model;

[0019] Figure 3 is a longitudinal sectional view of the electrochemical carbon monoxide sensor of the utility model;

[0020] Figure 4is a compressed structure schematic view of the embodiment 1 of the electrochemical carbon monoxide sensor of the utility model;

[0021] Figure 5 is a compressed structure schematic view of the embodiment 1 of the electrochemical carbon monoxide sensor of the utility model;

[0022] Figure 6 is a compressed structure schematic view of the embodiment 2 of the electrochemical carbon monoxide sensor of the utility model;

[0023] Figure 7 is a compressed structure schematic view of the embodiment 2 of the electrochemical carbon monoxide sensor of the utility model

[0024] Figure 8 is a compressed structure schematic view of the embodiment 3 of the electrochemical carbon monoxide sensor of the utility model;

[0025] Figure 9 is a compressed structure schematic view of the embodiment 3 of the electrochemical carbon monoxide sensor of the utility model

[0026] Figure 10 is a schematic diagram of the electrochemical reaction principle of the electrochemical carbon monoxide sensor of the utility model.

[0027] In the figure: 1000, carbon monoxide sensor, 100, gas inflow part, 110, anode terminal, 120, upper shell, 121, gas inflow buckle, 122, upper shell flange wing, 130, interference gas filter part, 131, first waterproof dustproof filter sheet, 132, activated carbon layer, 133, second waterproof dustproof filter sheet, 134, filter sheet support sheet, 134a, filter sheet support sheet gas inflow port, 140, sealing ring, 140-1, lower rubber layer, 200, membrane electrode reaction part, 210, anode support sheet, 211, gas inflow port, 220, anode current collector film positioning sheet, 221, anode current collector film positioning sheet positioning hole, 230, anode current collector film, 240, membrane electrode, 241, anode reaction surface, 242, cathode reaction surface, 250, cathode current collector film, 260, cathode current collector film positioning sheet, 261, cathode current collector film positioning sheet positioning hole, 270, cathode support sheet, 271, gas moisture inflow port, 272, cathode current collector film containing space, 300, outer shell, 310, reaction space, 311, hem part, 320, water containing space, 321, neck-in, 330, cathode terminal. DETAILED DESCRIPTION

[0028] In order to more clearly understand the above purpose, features and advantages of the present application, the present application will be described in detail below in conjunction with the drawings and specific embodiments. It should be noted that the embodiments and features in the embodiments can be combined with each other without conflict. In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, and the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as understood by those skilled in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application.

[0029] In the embodiments of the present application, in order to facilitate the description without limiting the present application, the term "connection" used in the patent application specification and claims of the present application is not limited to physical or mechanical connection, but can include electrical connection, whether direct or indirect. "Up", "down", "below", "left", "right" and the like are only used to represent the relative positional relationship, and when the absolute position of the described object changes, the relative positional relationship also changes accordingly.

[0030] For details, see the drawings Figures 1-3The embodiment provides an electrochemical carbon monoxide sensor 1000, which comprises a shell 300, the shell is divided into a reaction space 310 and a water containing space 320 through a neck 321, the shell is curved along a central direction at the top of the reaction space, and a curled edge part 311 is arranged on the upper surface of a sealing ring 140 and seals the upper shell 120, the inner cavity of the upper shell is sequentially provided with a first waterproof and dustproof filter sheet 131, an activated carbon layer 132, a second waterproof and dustproof filter sheet 133, a filter sheet support sheet 134, an anode support sheet 210, an anode current collector membrane positioning sheet 220 and a cathode support sheet 270 from top to bottom, the anode current collector membrane positioning sheet is sequentially provided with an anode current collector membrane 230, a membrane electrode 240 and a cathode current collector membrane 250 in the positioning hole 221, the anode current collector membrane, the membrane electrode and the cathode current collector membrane form a membrane electrode unit, the thickness of the anode current collector membrane positioning sheet is less than the thickness of the anode current collector membrane, the thickness of the cathode current collector membrane and the membrane electrode is greater than the thickness of the cathode current collector membrane positioning sheet, and the lower space between the upper surface of the cathode current collector membrane positioning sheet and the lower surface of the anode current collector membrane positioning sheet and the upper space between the upper surface of the anode current collector membrane positioning sheet and the lower surface of the anode support sheet are formed, the sealing ring contains the upper shell flange wing 122, the anode support sheet and the lower rubber layer 140-1 of the sealing ring, the sealing ring is pressed from the upper side, the anode support sheet is moved downward, and a mechanical power structure for compressing the membrane electrode unit is formed, the anode support sheet is in the shape of a circular disc with a stepped platform in the cross section, the outer edge of the circular disc-shaped anode support sheet is connected with the upper shell flange wing, the lower surface of the circular disc-shaped anode support sheet is connected with the lower rubber layer of the sealing ring, the height of the stepped boss of the circular disc-shaped anode support sheet is less than the thickness of the lower rubber layer of the sealing ring, the difference in height is 0.1mm-0.5mm, the stepped boss of the circular disc-shaped anode support sheet is in rigid limiting structure with the cathode support sheet after the stepped boss is moved downward and touches the anode current collector membrane positioning sheet, and the total compression rate of the membrane electrode unit through the rigid limiting structure is 10%-30%; the cathode support sheet is in the shape of a circular disc with a stepped platform in the cross section, the anode current collector membrane positioning sheet is arranged between the stepped boss bottom of the anode support sheet and the stepped recess of the cathode support sheet, the inner diameter of the positioning hole 221 of the circular ring-shaped anode current collector membrane positioning sheet is less than the outer diameter of the membrane electrode and the cathode current collector membrane, the inner circle of the anode current collector membrane positioning sheet is overlapped on the upper surface of the membrane electrode, and the sealing connection structure of the shell-sealing ring-anode current collector membrane positioning sheet-membrane electrode is formed.

[0031] Anode current collector film positioning piece positioning hole 221 is provided with anode current collector film 230, anode current collector film is partially placed on membrane electrode 240, membrane electrode 240 is connected with cathode current collector film 250, cathode current collector film is on cathode support piece 270, cathode support piece is supported on outer shell space area division table 321, first waterproof dustproof filter piece 131, activated carbon layer 132, second waterproof dustproof filter piece 133, filter piece support piece 134 and filter piece support piece gas flow inlet 134a constitute interference gas filter part 130, and the upper shell 120, gas flow inlet buckle 121, upper shell flange wing 122 and interference gas filter part 130 constitute gas inlet part 100.

[0032] Another scheme of the embodiment is that the cathode support piece is in the shape of a circular ring, and the cathode support piece and the anode support piece are provided with a cathode current collector film positioning piece 260 and an anode current collector film positioning piece 220, the cathode current collector film positioning piece is provided with a membrane electrode 240 and a cathode current collector film 250 in a center hole, and a cathode current collector film accommodating space 272 is arranged between the center hole of the cathode current collector film positioning piece and the membrane electrode 240 and the cathode current collector film, so as to accommodate the compression deformation amount of the membrane electrode and the cathode current collector film.

[0033] A preferred scheme of the embodiment is that the cross-sectional shape of the sealing ring is in the shape of an inverted “U”, the ratio of the upper thickness to the lower thickness is 3:1-6:1, the upper thickness is 1.5-1.8 mm, and the lower thickness is 0.3-0.6 mm.

[0034] The upper thickness of the sealing ring of the embodiment is 1.5 mm, and the lower thickness is 0.3 mm.

[0035] A preferred scheme of the embodiment is that the protruding height of the upper shell is 2-5 mm. The protruding height of the upper shell of the embodiment is 3 mm.

[0036] A preferred scheme of the embodiment is that the upper shell is fixedly connected with an anode terminal 110, the thickness of the anode terminal is 0.1-0.3 mm, and the anode terminal is made of a metal material. In the embodiment, the anode terminal is made of a nickel strip.

[0037] A preferred scheme of the embodiment is that the activated carbon layer is made of granular activated carbon or fibrous activated carbon cotton.

[0038] A preferred scheme of the embodiment is that the outer shell has a diameter of 14-17 mm, a height of 20-50 mm, and a thickness of 0.2-0.3 mm, and is made of a metal material. In the embodiment, the outer shell has a diameter of 14 mm, a height of 25 mm, and a thickness of 0.2 mm, and is made of a metal material. In the embodiment, the outer shell is made of stainless steel.

[0039] The preferred scheme of the embodiment is that the bottom of the shell is fixed with a cathode terminal 330, which has a thickness of 0.1-0.3 mm and is made of metal material. In this embodiment, the nickel strip is used.

[0040] The preferred scheme of the embodiment is that the anode support sheet has a diameter of 11-16 mm and a thickness of 0.6-1.0 mm, the center of the anode support sheet is provided with a gas flow inlet with a diameter of 0.15-0.3 mm, and the anode support sheet is made of metal material. In this embodiment, the anode support sheet has a diameter of 13 mm, a thickness of 0.8 mm, and a gas flow inlet with a diameter of 0.15 mm in the center of the anode support sheet, and the anode support sheet is made of stainless steel material.

[0041] The preferred scheme of the embodiment is that the anode current collector film positioning sheet has a thickness of 0.25-0.45 mm and is made of PET, PP or PE material. In this embodiment, the anode current collector film positioning sheet has a thickness of 0.4 mm and is made of PE material.

[0042] The preferred scheme of the embodiment is that the thickness of the anode current collector film and the thickness of the cathode current collector film are respectively 0.35-0.55 mm, and the anode current collector film and the cathode current collector film are made of PTFE (polytetrafluoroethylene) conductive gas diffusion film material. In this embodiment, the thickness of the anode current collector film and the thickness of the cathode current collector film are respectively 0.5 mm.

[0043] The preferred scheme of the embodiment is that the membrane electrode has a thickness of 0.1-0.2 mm and is made of MEA membrane electrode material. In this embodiment, the membrane electrode has a thickness of 0.1 mm.

[0044] The preferred scheme of the embodiment is that the cathode support sheet has an outer diameter of 11-16 mm and a thickness of 0.6-1.0 mm, a plurality of gas and moisture flow inlets are provided on the cathode support sheet, the gas and moisture flow inlets have a diameter of 0.15-0.3 mm, and the cathode support sheet is made of metal material. In this embodiment, the cathode support sheet has an outer diameter of 13 mm and a thickness of 0.8 mm, the gas and moisture flow inlets on the cathode support sheet have a diameter of 0.15 mm, and the cathode support sheet is made of stainless steel material.

[0045] Working principle of the electrochemical carbon monoxide sensor:

[0046] For details, see the accompanying drawings Figure 10 The center of the anode support sheet 210 is provided with a gas flow inlet 211, the cathode support sheet 270 is provided with a gas and moisture flow inlet 271, and the anode reaction surface 241 and the cathode reaction surface 242 of the membrane electrode 240 between the anode support sheet and the cathode support sheet each undergo oxidation and reduction reactions, respectively, and generate an electric current, and the size of the electric current is proportional to the amount of carbon monoxide oxidation reaction, so that the concentration of carbon monoxide can be measured. The reaction formula of the reaction occurring on the anode reaction surface and the cathode reaction surface is as follows:

[0047] Reaction 1 (anode): CO + H2O → CO2+ 2H + + 2e -

[0048] Reaction 2 (cathode): 1 / 2O2+ 2H + + 2e - → H2O

[0049] Net reaction: CO + 1 / 2O2 → CO2

[0050] Carbon monoxide gas flowing in through the gas inlet of the anode support sheet is oxidized by reaction 1 with water at the membrane electrode anode reaction surface through the anode current collector membrane, and carbon monoxide is oxidized to carbon dioxide while water molecules are decomposed to hydrogen ions (H+). The hydrogen ions are reduced to water by reaction 2 with oxygen flowing in through the cathode current collector membrane and the gas water inlet at the cathode reaction surface. The movement of electrons generated in the above reaction process generates an electric current.

[0051] The key technology of the utility model is: in the process of shell hemming, the sealing ring, the upper shell flange wing and the anode support sheet are extruded under stress, at this time, the anode current collector membrane, the membrane electrode and the cathode current collector membrane will produce a downward compression amount. The improved structure of the utility model adopts a mechanical limiting structure, which can make the compression amount of the anode current collector membrane, the membrane electrode and the cathode current collector membrane independent of the shell hemming amount and the elastic deformation compression amount of the sealing ring, so that the anode current collector membrane, the membrane electrode and the cathode current collector membrane are limited in a fixed compression amount range. The height ratio (H2 / H1) value of the anode / cathode current collector membrane and the membrane electrode before and after compression is limited to 70%~90%. The inner diameter of the anode current collector membrane positioning sheet is smaller than the outer diameter of the membrane electrode and the cathode current collector membrane, the inner circle of the anode current collector membrane positioning sheet is placed on the membrane electrode 240, and the sealing between the shell-sealing ring-anode current collector membrane positioning sheet-membrane electrode is blocked, so that the water vapor flowing out through the cathode current collector membrane is prevented from directly evaporating through the anode current collector membrane, the evaporation speed of the water-soluble substance in the sensor is slowed down, and the service life of the sensor is prolonged.

[0052] The structural characteristics of the utility model are: when the upper shell compresses the anode current collector membrane through the anode support sheet, the anode support sheet tightly adheres to the anode current collector membrane positioning sheet and the cathode support sheet, and plays a mechanical limiting role. Regardless of the pressure of the upper shell, a certain height space is always maintained between the anode support sheet and the cathode support sheet at this time, therefore, the compression amount range of the anode current collector membrane, the membrane electrode and the cathode current collector membrane can be limited / maintained at a fixed value, (in an ideal state, in the range of 10~30%) so that the dispersion of electrical characteristics between carbon monoxide gas sensor products is minimized. Embodiment

[0053] See the attached Figures 4-5The system includes an outer shell 300, which is divided into a reaction space 310 and a water-containing space 320 by a necking 321. The upper end of the reaction space is provided with a rolled edge portion 311, which, after being rolled, encloses a sealing ring 140. An upper shell 120 and an anode support plate 210 are fitted inside the sealing ring. From top to bottom, the upper shell contains a first waterproof and dustproof filter 131, an activated carbon layer 132, a second waterproof and dustproof filter 133, a filter support plate 134, an anode support plate 210, and an anode current collector membrane 230. The system comprises a membrane electrode 240, a cathode current collector 250, an anode current collector positioning plate 220, and a cathode support plate 270. An anode current collector 230 is placed in the positioning hole 221 of the anode current collector positioning plate, with a portion of the anode current collector partially resting on the membrane electrode 240 near its center. The cathode current collector 250 is connected below the membrane electrode 240, and the cathode current collector rests on the cathode support plate 270. The cathode support plate is supported on the outer shell necking 321. The compression ratio of the three layers—the anode current collector, the membrane electrode, and the cathode current collector—is 10%-30%. A gas inlet 121 is located at the upper end of the upper shell, and an upper shell flange 122 is located at the bottom of the upper shell. A gas inlet 134a is located on the filter support plate.

[0054] In this embodiment, the anode support plate 210 is a stepped disc shape, and the cathode support plate 270 is also a stepped disc shape. An anode current collector positioning plate 220 is placed between the bottom of the stepped platform of the anode support plate 210 and the stepped recess of the cathode support plate 270. Figure 4 As shown, H1 is formed when the anode support plate 210 is pressed down. Figure 5 The limiting height H2 ensures that the compressibility of the anode / cathode current collector and membrane electrode is H2 / H1 = 0.7~0.9.

[0055] The cathode support plate 270 shown has a chamfered central stepped platform, which forms a cathode current collector receiving space 272 between itself and the membrane electrode 240 and the cathode current collector 250, which can accommodate the compression deformation of the membrane electrode and the cathode current collector. Example

[0056] See appendix for details Figures 6-7An electrochemical carbon monoxide sensor 1000 comprises a shell 300, which is divided into a reaction space 310 and a water-containing space 320 by a neck 321, and is provided with a curled edge portion 311 at the upper end of the reaction space, which contains a sealing ring 140 after curling, and the inner circle of the sealing ring is sleeved with an upper shell 120 and an anode support sheet 210, the inner circle of the upper shell is sequentially provided from top to bottom with a first waterproof and dustproof filter sheet 131, an activated carbon layer 132, a second waterproof and dustproof filter sheet 133, a filter sheet support sheet 134, the anode support sheet 210, an anode current collector film 230, a membrane electrode 240, a cathode current collector film 250, an anode current collector film positioning sheet 220 and a cathode support sheet 270, the anode current collector film 230 is arranged in the positioning hole 221 of the anode current collector film positioning sheet, the anode current collector film is partially overlapped on the membrane electrode 240 at the central part, the membrane electrode 240 is connected with the cathode current collector film 250 below, the cathode current collector film is above the cathode support sheet 270, the cathode support sheet is supported on the neck 321 of the shell, and the compression rate of the three layers of the anode current collector film, the membrane electrode and the cathode current collector film is 10%-30%. The upper end of the upper shell is provided with a gas inlet 121, the bottom of the upper shell is provided with an upper shell flange wing 122, and the filter sheet support sheet is provided with a gas inlet 134a.

[0057] The cathode support sheet is in a circular ring shape, and the cathode support sheet and the anode support sheet are provided with a cathode current collector film positioning sheet 260 and an anode current collector film positioning sheet 220, as shown in Figure 6 h1, when the anode support sheet 210 is pressed down, h1 forms Figure 7 a limiting height h2, which can ensure that the compression rate of the anode / cathode current collector film and the membrane electrode is h2 / h1=0.7~0.9.

[0058] The membrane electrode 240 and the cathode current collector film 250 are arranged in the positioning hole 261 of the cathode current collector film positioning sheet, and a cathode current collector film containing space 272 is arranged between the positioning hole of the cathode current collector film positioning sheet and the membrane electrode 240 and the cathode current collector film, which can contain the compression deformation amount of the membrane electrode and the cathode current collector film. Embodiment

[0059] See the attached Figures 8-9An electrochemical carbon monoxide sensor 1000 comprises a shell 300, which is divided into a reaction space 310 and a water-containing space 320 by a neck 321, the upper end of the reaction space is provided with a curled edge portion 311, the curled edge portion contains a sealing ring 140 after curling, the inner circle of the sealing ring is sleeved with an upper shell 120 and an anode support sheet 210, the inner circle of the upper shell is sequentially provided from top to bottom with a first waterproof and dustproof filter sheet 131, an activated carbon layer 132, a second waterproof and dustproof filter sheet 133, a filter sheet support sheet 134, the anode support sheet 210, an anode current collector film 230, a membrane electrode 240, a cathode current collector film 250, an anode current collector film positioning sheet 220 and a cathode support sheet 270, the anode current collector film 230 is arranged in the positioning hole 221 of the anode current collector film positioning sheet, the anode current collector film is partially arranged on the membrane electrode 240 at the central part, the cathode current collector film 250 is connected to the lower surface of the membrane electrode 240, the cathode current collector film is arranged on the upper surface of the cathode support sheet 270, the cathode support sheet is supported on the neck 321 of the shell, and the compression rate of the three layers of the anode current collector film, the membrane electrode and the cathode current collector film is 10%-30%. The upper end of the upper shell is provided with a gas inlet 121, the bottom of the upper shell is provided with an upper shell flange wing 122, and the filter sheet support sheet is provided with a gas inlet 134a.

[0060] The bottom of the anode support sheet is a plane, and the bottom of the anode support sheet is in contact with the lower rubber layer of the sealing ring. The lower rubber layer 140-1 of the sealing ring, the anode current collector film positioning sheet 220 and the cathode current collector film positioning sheet 260 are arranged between the anode support sheet and the cathode support sheet, as shown in T1. Figure 8 When the anode support sheet 210 is pressed downward, T1 forms Figure 9 a limiting height T2, so as to ensure that the compression rate of the anode / cathode current collector film and the membrane electrode is T2 / T1=0.7~0.9. The design thickness of the lower rubber layer 140-1 should be beyond the elastic deformation range, so that the sealing ring is basically similar to a rigid part after being compressed.

[0061] The above-mentioned detailed description of the electrochemical carbon monoxide sensor is illustrative rather than limiting, and a plurality of embodiments can be listed within the limited range, and therefore the changes and modifications within the overall concept of the utility model should be within the protection scope of the utility model.

Claims

1. An electrochemical carbon monoxide sensor comprising a housing, the housing is divided into a reaction space and a water containing space by a neck, the housing is curved along the center direction at the top of the reaction space, having a curled edge part that pressurizes downward and contains the upper surface of a sealing ring, the sealing ring is sealingly connected with an upper shell, the inner cavity of the upper shell is sequentially provided with a first waterproof and dustproof filter, an activated carbon layer, a second waterproof and dustproof filter, a filter support sheet, an anode support sheet, an anode current collector film positioning sheet and a cathode support sheet from top to bottom, the positioning holes of the anode current collector film positioning sheet are sequentially provided with an anode current collector film, a membrane electrode and a cathode current collector film, the three layers of the anode current collector film, the membrane electrode and the cathode current collector film constitute a membrane electrode unit, the thickness of the anode current collector film positioning sheet is less than the thickness of the anode current collector film, the thickness of the stack of the cathode current collector film and the membrane electrode is greater than the thickness of the cathode current collector film positioning sheet, forming a lower space between the upper surface of the cathode current collector film positioning sheet and the lower surface of the anode current collector film positioning sheet, and an upper space between the upper surface of the anode current collector film positioning sheet and the lower surface of the anode support sheet, the sealing ring contains the flange wing of the upper shell, the anode support sheet and the lower rubber layer of the sealing ring, the sealing ring is pressed on the upper side, the anode support sheet moves downward, and the mechanical power structure for pressing the membrane electrode unit is formed, characterized in that: The anode support sheet is in the shape of a circular disc with a stepped platform in cross section, the outer edge of the circular disc-shaped anode support sheet is connected with the upper shell flange wing, the lower surface is connected with the lower rubber layer of the sealing ring, the stepped platform of the circular disc-shaped anode support sheet is lower than the thickness of the lower rubber layer of the sealing ring, the difference in height is 0.1mm-0.5mm, the stepped platform of the circular disc-shaped anode support sheet is lowered to touch the anode current collector film positioning sheet, and a rigid limiting structure is formed with the cathode support sheet, and the total compression rate of the membrane electrode unit through the rigid limiting structure is 10%-30%; the cathode support sheet is in the shape of a circular disc with a stepped platform in cross section, a circular ring-shaped anode current collector film positioning sheet is arranged between the stepped platform of the anode support sheet and the stepped concave platform of the cathode support sheet, the inner diameter of the circular ring-shaped anode current collector film positioning sheet is smaller than the outer diameter of the membrane electrode and the cathode current collector film, the inner circle of the anode current collector film positioning sheet is placed on the upper surface of the membrane electrode, and a sealed connection of the shell-sealing ring-anode current collector film positioning sheet-membrane electrode is formed.

2. The electrochemical carbon monoxide sensor according to claim 1, characterized in that: The cathode support sheet is in the shape of a circular ring, the cathode support sheet and the anode support sheet are provided with a cathode current collector film positioning sheet and an anode current collector film positioning sheet, a membrane electrode and a cathode current collector film are arranged in the central circular hole of the cathode current collector film positioning sheet, and a cathode current collector film containing space is arranged between the central circular hole of the cathode current collector film positioning sheet and the membrane electrode and the cathode current collector film, which can accommodate the compression deformation amount of the membrane electrode and the cathode current collector film.

3. The electrochemical carbon monoxide sensor of claim 1, wherein: The cross-sectional shape of the sealing ring is in the shape of an inverted "U", the ratio of the upper thickness to the lower thickness is 3:1-6:1, the upper thickness is 1.5-1.8mm, and the lower thickness is 0.3-0.6mm.

4. The electrochemical carbon monoxide sensor of claim 1, wherein: The active carbon layer adopts granular activated carbon or fibrous activated carbon cotton.

5. The electrochemical carbon monoxide sensor of claim 1, wherein: The shell has a diameter of 14-17mm, a height of 20-50mm, and a thickness of 0.2-0.3mm, and is made of stainless steel material.

6. The electrochemical carbon monoxide sensor of claim 1, wherein: The anode support sheet has a diameter of 11-16mm and a thickness of 0.6-1.0mm, a gas flow inlet with a diameter of 0.15-0.3mm is arranged in the center of the anode support sheet, and the anode support sheet is made of stainless steel material.

7. The electrochemical carbon monoxide sensor of claim 1, wherein: The anode current collector film positioning sheet has a thickness of 0.25-0.45mm and is made of PET, PP or PE material.

8. The electrochemical carbon monoxide sensor of claim 1, wherein: The thickness of the anode current collector film and the thickness of the cathode current collector film are 0.35-0.55mm respectively, and the PTFE conductive gas diffusion film material is used.

9. The electrochemical carbon monoxide sensor of claim 1, wherein: The thickness of the membrane electrode is 0.1-0.2mm, and the MEA membrane electrode material is used.

10. The electrochemical carbon monoxide sensor of claim 1, wherein: The cathode support sheet has an outer diameter of 11-16mm and a thickness of 0.6-1.0mm, a plurality of gas and moisture flow inlets with a diameter of 0.15-0.3mm are arranged on the cathode support sheet, and the cathode support sheet is made of stainless steel material.

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