Contact combustion type gas sensor and manufacturing method thereof

Abstract

The present invention relates to a contact combustion gas sensor provided with a coil-exposed detection element for detecting flammable gas leakage, and a method for manufacturing the same, the contact combustion gas sensor being provided with a detection element (210) that reacts with contact gas and a compensation element (260) that does not react with contact gas, the detection element (210) comprising a coil wire (222) and a thermal block (240), the coil wire (222) has a coil shape, an exposed portion of the coil wire (222) that is in direct contact with the outside air performs a direct catalyst combustion reaction with gas in contact with the outside air, and the thermal block (240) is disposed inside the coil wire (222), and a portion of the thermal block (240) is coupled to the coil wire (222) to support the coil wire (222).

Description

[Technical Field]

[0001] This invention relates to a contact combustion type gas sensor for detecting flammable gas leaks and a method for manufacturing the same, wherein the gas sensor has a coil-exposed detection element. [Background Technology]

[0002] In many fields, such as hydrogen fuel cells in hydrogen-powered vehicles or distributed cogeneration power generation units, heating equipment such as boilers, cooking equipment such as kitchens in homes and restaurants, handling equipment such as automobiles, and industrial heating equipment, flammable gases such as hydrogen, methane, and propane are used. In order to prevent leakage and explosion, most of them are obligated to use contact combustion gas sensors.

[0003] The contact combustion gas sensor comprises a detection element and a compensation element, and is measured using a Wheatstone bridge circuit method. The detection and compensation elements share the following characteristics: both involve coating a composite ceramic slurry based on alumina in a loop shape onto a platinum coil with the same resistance; and both operate by heating the platinum coil to approximately 300–350 degrees Celsius. The difference lies in the fact that, only the detection element has a platinum or palladium nanocatalyst dispersed / added on its surface, facilitating a combustion reaction upon contact with combustible gases (methane, propane, hydrogen, isobutane, etc.), and detecting the increase in resistance of the platinum coil accompanying the combustion reaction. Simultaneously, the resistance of the compensation element, which lacks a dispersed catalyst and does not exhibit a combustion reaction, is used as a reference.

[0004] Contact combustion gas sensors play a crucial role in preventing major accidents by detecting leaks of city gas (synthetic natural gas), propane, and, most recently, hydrogen, through alarms and valve closures. Occasionally, however, gas leaks may occur but alarms may be delayed or absent entirely. While the cause is often difficult to pinpoint after an incident, it is presumed to be due to imperfections in the detection and compensation technologies of the contact combustion gas sensors.

[0005] <Prior Technology Documents>

[0006] (Patent Document 1) JP 4578990 B2 [Summary of the Invention] [Technical Issues]

[0007] The purpose of this invention is to provide a contact combustion type gas sensor. [Technical Solution]

[0008] According to an embodiment of the present invention, a contact combustion gas sensor with a coil exposed detection element may include the detection element 210 and a compensation element 260. The detection element 210 reacts with the contact gas, while the compensation element 260 does not react with the contact gas. The detection element 210 includes: a coil wire 222, which is coil-shaped, and the exposed portion of the coil wire 222 that is in direct contact with external air undergoes a direct catalytic combustion reaction with the contact gas in the external air; and a heat block 240, which is disposed inside the coil wire 222 and a portion of which is combined with the coil wire 222 to support the coil wire 222.

[0009] In addition, the coil wire 222 mentioned above can be made of platinum-based materials.

[0010] Furthermore, the exposed portion ratio of the aforementioned coil wire 222 can be 40% to 90% of the surface area of ​​the aforementioned coil wire 222.

[0011] In addition, the aforementioned hot block 240 may have a cover module that covers a portion of the aforementioned coil wire 222.

[0012] Furthermore, the aforementioned cover module is at least one of module ring 245 and module rod 246. The module ring 245 is a portion of the area surrounding the aforementioned coil wire 222, and the module rod 246 is rod-shaped and attached to the aforementioned heat block 240 along the length direction of the aforementioned heat block 240.

[0013] In addition, the coil wire 222 can be one of the platinum group metals such as platinum (Pt), palladium (Pd), rhodium (Rh), iridium (Ir) and ruthenium (Ru), or an alloy of two or more of the above platinum group metals.

[0014] Furthermore, the wire diameter of the direct catalytic combustion reaction coil 220 is preferably 5 to 40 μm. The resistance of the direct catalytic combustion reaction coil 220 at room temperature is preferably 2 to 20 Ω. The coil diameter of the direct catalytic combustion reaction coil 220 is preferably 0.1 to 0.5 mm. The number of turns (windings) of the direct catalytic combustion reaction coil 220 is preferably 7 to 15 turns.

[0015] In addition, a direct catalytic combustion reaction coil 220 may be included, which has the aforementioned coil wires 222.

[0016] In addition, the direct catalytic combustion reaction coil 220 is powered and releases heat to maintain the preset reaction operating temperature; the direct catalytic combustion reaction in contact with the gas generates heat of combustion so that the temperature can be raised to a level higher than the reference operating temperature of the compensation element 260.

[0017] In addition, the aforementioned hot block 240 retains the aforementioned power source heat and combustion heat to reduce heat loss. The hot block 240 has pores inside, which react with the aforementioned contact gas to generate additional heat through catalytic combustion.

[0018] In addition, the aforementioned hot block 240 can be a cylindrical, elliptical, or polygonal column shape.

[0019] In addition, the aforementioned hot block 240 is divided into multiple modules, including a base module and an adhesive module. The base module serves as the internal foundation, and the adhesive module 244 connects the base module 242 and the direct catalyst combustion reaction coil 220.

[0020] Furthermore, the aforementioned basic module 242 may be one of the following: a metal oxide rod containing at least one of oxidized Co, Ni, Mn, Cr, Ti, Cu, Sn, Fe, V, Ag, In, La, W, and Zn; a ceramic rod containing at least one of alumina and silicon dioxide; or a composite ceramic rod containing the aforementioned metal oxide and the aforementioned ceramic oxide.

[0021] In addition, the aforementioned adhesive module 244 may contain at least the aforementioned transition metal oxide and precious metal powder.

[0022] In addition, the aforementioned compensation element 260 may include a compensation element coil and a compensation element surround, wherein the compensation element coil 270 serves as a coil-type electrode wire, and the compensation element surround 280 surrounds the aforementioned compensation element coil 270.

[0023] In addition, the aforementioned compensation element coil 270 can convert electrical energy into heat energy to achieve the aforementioned reference operating temperature.

[0024] Furthermore, the aforementioned compensation element coil 280 can disconnect the aforementioned compensation element coil 270 from the aforementioned external air.

[0025] Furthermore, the aforementioned compensation element ring 280 may be free of internal gaps and connecting channels.

[0026] Furthermore, the aforementioned compensation element coil 270 may include a coil conductor 272 and a ring-through conductor 274. The coil conductor 272 is spiral in shape, and the ring-through conductor 274 connects one end of the coil conductor 272 to the power supply and passes through the compensation element ring 280. The compensation element ring 280 is cylindrical in shape and has a ring protrusion 282 formed in the through portion of the ring-through conductor 274.

[0027] Furthermore, the coil wire 272 may be cylindrical, and the distance between the coil wire 272 and the surface of the compensation element ring 280 is the shortest between the cylindrical side of the coil wire 272 and the surface of the compensation element ring 280.

[0028] Furthermore, the aforementioned compensation element ring 280 can be formed from two or more of the following pastes: alumina, silicon oxide, and metal oxide, and an inorganic binder.

[0029] A method for manufacturing a contact combustion gas sensor with an exposed coil detection element according to an embodiment of the present invention is provided. The contact combustion gas sensor is cylindrical and includes a detection element 210 and a compensation element 260. The detection element 210 reacts with the contact gas, while the compensation element 260 does not react with the contact gas. The manufacturing method includes: a base module 242 manufacturing step, wherein the base module 242 serves as an internal base among multiple modules of a hot block 240, and the hot block 240 supports a direct catalytic combustion reaction coil 220, which is a platinum-based coil that is in contact with external air in the detection element 210 and directly undergoes catalytic combustion reaction with the contact gas; an adhesive module 244 manufacturing step, wherein the adhesive module 244 is used to connect the base module 242 and the direct catalytic combustion reaction coil 220; and a compensation element surround 280 manufacturing step, wherein the compensation element surround 280 is used to surround the compensation element coil 270, which serves as a coil-type electrode wire in the compensation element 260.

[0030] In addition, the aforementioned compensation element ring 280 can be a cylindrical shape with protrusions at both ends.

[0031] Furthermore, the manufacturing steps of the aforementioned basic module 242 include: a basic module slurry manufacturing step, in which an organic binder or carbon powder is added to one of the following powders: an oxidized metal oxide powder containing at least one of Co, Ni, Mn, Cr, Ti, Cu, Sn, Fe, V, Ag, In, La, W and Zn; a ceramic powder containing at least one of alumina and silicon dioxide; and a composite ceramic powder containing the aforementioned metal oxide powder and the aforementioned ceramic powder; and a drying and low-temperature heat treatment step, in which the aforementioned basic module slurry is shaped into a specific shape and the shaped basic module slurry is dried and subjected to low-temperature heat treatment.

[0032] In addition, the aforementioned composite ceramic powder can have an intermediate particle size of 0.1 to 10 μm to ensure air permeability.

[0033] In addition, the manufacturing steps of the above-mentioned adhesive module 244 may include: an adhesive module slurry manufacturing step, which involves adding at least one of CuO, ZnO, SnO2, TiO2, NiO, Co3O4, MnO2, AgO2, WO3 and precious metal powders to the base module slurry to enable the contact gas to undergo catalytic combustion, thereby manufacturing the adhesive module slurry; and a step of applying the adhesive module slurry to the surface of the base module 242 and then performing drying and high-temperature heat treatment.

[0034] Furthermore, the manufacturing steps of the aforementioned compensation element coil 280 include: a coil core module slurry manufacturing step; a coil core 285 forming step, in which the coil core module slurry is applied to the compensation element coil 270, and then dried and subjected to low-temperature heat treatment to form a circular or elliptical coil core; a coil outer surface module slurry manufacturing step, wherein the coil outer surface module slurry is made of the same material as the coil core module slurry, but with a higher viscosity; and a coil outer surface 286 forming step, in which the coil outer surface module slurry is applied to the outer surface of the coil core 285 to form a cylindrical shape with protrusions at both ends, and then dried and subjected to high-temperature heat treatment to form the coil outer surface 286.

[0035] In addition, the above-mentioned core module slurry may contain: composite ceramic powder, which contains metal oxide powder and ceramic powder, wherein the metal oxide powder is at least one of oxidized Ti, Cu, Sn and Zn, and the ceramic powder contains at least one of alumina and silicon dioxide; inorganic binder; and one of water and alcohol.

[0036] In addition, the particle size of each component material of the above-mentioned outer surface module slurry can be below 50 nm. [Invention Effects]

[0037] In the manufacture of the detection element of a contact combustion gas sensor with an exposed coil detection element, platinum and palladium nanoparticle dispersed catalysts can be eliminated, thereby reducing costs. Furthermore, by preventing the release of toxic substances such as chlorine and preventing catalyst poisoning of the nanoparticles, the sensor sensitivity can be prevented from decreasing over time.

[0038] Furthermore, the manufacturing process for the detection element is simplified because a double-ring layer is not required.

[0039] Furthermore, if a cylindrical compensating element with a handle is used in the manufacturing process, it can prevent or suppress the formation of vents at both ends of the coil and the electrode wire section, thus ensuring stable operation under any harsh operating conditions. Its effectiveness is particularly pronounced in small, highly unstable, and flammable gases such as hydrogen.

[0040] In addition, contact combustion gas sensors with exposed coil detection elements have a longer lifespan and can prevent false alarms and / or delayed alarms. [Attached Image Description]

[0041] Figure 1 This is a three-dimensional view of a contact combustion gas sensor with an exposed coil detection element.

[0042] Figure 2 yes Figure 1 A three-dimensional view of the detection element.

[0043] Figure 3 and Figure 4 To illustrate the leakage level of the direct catalytic combustion reaction coil used for detecting the element, a longitudinal section of the direct catalytic combustion reaction coil is shown. Figure 2 A cross-sectional view of part A.

[0044] Figure 5 yes Figure 2 A cross-sectional view of a hot block or a hot block with a coiled wire.

[0045] Figure 6 and Figure 7 yes Figure 1 Cross-sectional view of the compensation element.

[0046] Figures 8-11 This is a flowchart of a manufacturing method for a contact combustion gas sensor with an exposed coil detection element.

[0047] Figure 12 This is a perspective view of the existing detection module corresponding to the detection element of this application.

[0048] Figure 13 and Figure 14 This is a perspective view of the detection element based on other embodiments.

[0049] Figure 15 This is a front view of a detection element based on yet another embodiment. Figure 16 yes Figure 15 Cross-sectional view of BB'.

Detailed Implementation Methods

[0050] The present invention will now be described in more detail with reference to the accompanying drawings.

[0051] The terms "first," "second," etc., can be used to describe multiple constituent elements, but the constituent elements should not be limited by these terms. The purpose of using these terms is solely to distinguish one constituent element from others. For example, without departing from the scope of this invention, a first constituent element can be named a second constituent element, and similarly, a second constituent element can be named a first constituent element. Terms such as "and / or" include a combination of multiple related described items or one of multiple related described items. Although "or" can be interpreted as exclusive and in context, generally, unless explicitly stated as "otherwise," "logically exclusive," etc., it is interpreted as "and / or," i.e., logical sum.

[0052] When a component is mentioned as being "connected" or "connected" to other components, it may be directly connected or connected to other components, but it should be understood that other components may exist in between. Conversely, when a component is "directly connected" or "directly connected" to other components, it should be understood that no other components exist in between. The connection or connection between the first and second components on a network indicates that data can be sent and received between the first and second components via wired or wireless means.

[0053] Furthermore, the suffixes “module” and “section” used in the following description for the purpose of writing this specification are used purely for convenience and do not have any particularly important meaning or function in themselves. Therefore, the terms “module” and “section” may be used interchangeably.

[0054] In practical applications, such constituent elements may be combined from two or more constituent elements to form one constituent element, or one constituent element may be subdivided into two or more constituent elements, depending on the needs. The same reference numerals are assigned to the same or similar constituent elements throughout the drawings. Detailed descriptions of constituent elements with the same reference numerals may be omitted as they are replaced by descriptions of the aforementioned constituent elements.

[0055] Furthermore, this invention includes all possible combinations of the embodiments shown in this specification. While the various embodiments of the invention differ from one another, they are not mutually exclusive. One embodiment with a particular shape, structure, function, and characteristic described in this specification can be implemented through other embodiments. For example, the constituent elements mentioned in the first and second embodiments can perform all the functions of the first and second embodiments.

[0056] When flammable gases react with oxygen, they generate heat. Contact combustion gas sensors with exposed coil detection elements convert this heat into an electrical signal to detect the gas. These sensors can be used for detecting city gas or propane, as well as flammable and toxic gases in hydrogen-powered vehicles and factories.

[0057] Figure 1 This is a three-dimensional view of a contact combustion gas sensor with an exposed coil detection element. Figure 2 yes Figure 1 A three-dimensional view of the detection element. Figure 13 This is a perspective view of the detection element based on other embodiments. Figure 3 and Figure 4 To illustrate the leakage level of the direct catalytic combustion reaction coil used for detecting the element, a longitudinal section of the direct catalytic combustion reaction coil is shown. Figure 2 A cross-sectional view of part A. Figure 5 yes Figure 2 A cross-sectional view of a hot block or a hot block with a coiled wire. Figure 6 and Figure 7 yes Figure 1 Cross-sectional view of the compensation element. Figures 8-11 This is a flowchart of a manufacturing method for a contact combustion gas sensor with an exposed coil detection element. Figure 12 This is a perspective view of the existing detection module corresponding to the detection element of this application. Figure 13 and Figure 14 This is a perspective view of the detection element based on other embodiments. Figure 15 This is a front view of a detection element based on yet another embodiment. Figure 16 yes Figure 15 Cross-sectional view of BB'.

[0058] Reference Figure 1 According to an embodiment of the present invention, a contact combustion gas sensor with an exposed coil detection element may include a detection element 210 and a compensation element 260. The detection element 210 reacts with the contact gas, while the compensation element 260 does not react with the contact gas. The "contact gas" is a combustible gas and can be selected according to the operating temperature of the detection element 210.

[0059] Reference Figure 2 The detection element 210 may include a direct catalyst combustion reaction coil 220 and a hot block 240.

[0060] At least a portion of the direct catalytic combustion reaction coil 220 is in contact with outside air. The direct catalytic combustion reaction coil 220 can undergo a direct catalytic combustion reaction with the contact gas. A heating element 240 can support the direct catalytic combustion reaction coil 220. The heating element 240 can be disposed inside the direct catalytic combustion reaction coil 220. Specifically, the heating element 240 can be disposed inside the coil conductor 222.

[0061] Reference Figure 12The existing detection module 120 is configured such that its surrounding surface undergoes a catalytic combustion reaction with the contact gas to change its internal resistance. The detection module 120 may include: a detection module platinum wire 122, a detection module surrounding ring 124, and a detection module nano-dispersed catalyst layer 126.

[0062] The nano-dispersed catalyst layer 126 of the detection module can be disposed on the surface of the detection module enclosure 124. The nano-dispersed catalyst layer 126 can be a layer in which a catalyst such as platinum or palladium is dispersed in nano-sized particles and attached to the surface of the detection module enclosure 124. When the catalyst in the nano-dispersed catalyst layer 126 comes into contact with combustible gases (methane, propane, hydrogen, isobutane, etc.), a combustion reaction easily occurs, causing the temperature of the detection module enclosure 124 to rise. This temperature rise in the detection module enclosure 124 leads to a further increase in the temperature of the internal detection module platinum wire 122, subsequently increasing the resistance value of the platinum wire 122.

[0063] In the detection module 120, because a two-layer carrier coating of alumina composite slurry is applied to the platinum coil, and noble metal catalyst particles such as nano-platinum are dispersed and attached to the surface, catalyst poisoning may occur. This can lead to reduced sensor sensitivity and shortened sensor lifespan.

[0064] In addition, the detection module 120 also needs to undergo a process of holding palladium chloride solution and heat treatment at around 600°C, which may lead to environmental pollution problems such as the emission of toxic gases such as chlorine and hydrogen chloride.

[0065] Furthermore, the catalyst on the outer surface of the detection module enclosure 124, namely the nano-dispersed catalyst layer 126 of the detection module, is mainly located in the micropores. The catalyst may be buried over time due to constant heating above 300°C, and the nanoparticles may aggregate, reducing or eliminating the sensor performance. It may also react with other impurity elements (Cl, F, S, P, Pb, As, Si, Ca, Na, etc.) inside or outside the detection module enclosure 124, causing a decrease in catalyst performance.

[0066] These factors cause contact combustion gas sensors to trigger false alarms or have a short lifespan of less than 2 years.

[0067] The biggest problem in the manufacturing of existing detection elements is the method, chemical materials, and processes used to uniformly coat the surface of the nano-platinum group dispersible catalyst onto the ring surface. The treatment of the nano-catalyst on the ring surface is crucial. Solutions to these problems include preventing burial within micropores, preventing nanoparticle aggregation or crystallization caused by time-varying temperature changes during isothermal heating, preventing the loss of nano-catalyst dispersion due to interruption of reactions with other impurities within or from the outside of the ring, and modifying the detection method based on the nano-catalyst dispersion morphology. Furthermore, reducing or eliminating the use of chemicals such as palladium chloride in material processing, omitting high-temperature heat treatment processes, and eliminating processes that release toxic gases such as chlorine and hydrogen chloride can also be solutions to these problems.

[0068] Accordingly, the detection element 210 of this invention abandons the existing catalyst combustion method that uses platinum, palladium, or other nanocatalysts dispersed in a double-ring structure. Instead, the detection element 210 can directly initiate a direct catalytic combustion reaction on the surface of a platinum wire using a platinum-based microcoil. Furthermore, to further improve efficiency, a co-catalytic ceramic-shaped hot mass can be formed inside the platinum-based coil, and a breathable insulating agent can be used to maintain a high temperature above 300°C with low power, thereby expanding the reaction area and promoting the catalytic combustion reaction through latent heat characteristics and far-infrared radiation.

[0069] Therefore, in the contact combustion gas sensor of the present invention, which has a coil exposure type detection element, the ratio of the longitudinal profile of the coil wire 222, in which the hot block 240 is wound in the direct catalytic combustion reaction coil 220, to the outside is preferably 40% to 90%. The direct catalytic combustion reaction coil 220 may include: coil wire 222; and connecting wire 224 for connecting the power supply and the coil wire 222.

[0070] The coil conductor 222 can be in the shape of a coil. In the coil shape of the coil conductor 222, the exposed portion that is in direct contact with the outside air can undergo a direct catalytic combustion reaction with the catalytic combustion gas. The hot block 240 can be disposed within the direct catalytic combustion reaction coil 220, particularly inside the coil conductor 222, and can be partially combined with the coil conductor 222 to support the coil conductor 222.

[0071] The exposed portion ratio of the coil wire 222 can be 40% to 90% of the surface area of ​​the coil wire 222.

[0072] If the exposed ratio of the coil wire 222 is less than 40%, the catalytic combustion reaction between the coil wire 222 and the contact gas becomes too small, and the resistance change may be minimal. If the exposed ratio of the coil wire 222 is greater than 90%, excessive heat is released into the air while maintaining the operating temperature of the coil wire 222, leading to increased power consumption, reduced bonding force between the coil wire 222 and the hot block 240, and potential detachment between the coil wire 222 and the hot block 240. Therefore, the exposed ratio of the coil wire 222 is preferably 40% to 90%.

[0073] The exposure ratio of the coil wire 222 represents the ratio of the exposed portion to the total surface area of ​​the coil wire 222. The exposure ratio of a specific part of the coil wire 222 can be 40% to 90%. This is because, as mentioned earlier, the degree of heat release, the degree of bonding, and the degree of reaction need to be considered. (Refer to...) Figure 3 and Figure 4 The exposure ratio of a specific part of the coil conductor 222 can represent the ratio of the exposed arc (222-1) length or central angle to the circumference (222-1 & 222-2) of the longitudinal section of the coil conductor 222. Figure 3 The exposure ratio is shown to be 40%. Figure 4 The exposure rate is shown to be 90%.

[0074] The exposure ratio of the coil wire 222 can be adjusted by the slurry viscosity, which will be described later.

[0075] The exposure ratio of all parts of the coil conductor 222 is not limited to 40%–90%. (Refer to...) Figures 13-16 The heating block 240 may include a cover module (245, 246, etc.) that covers a portion of the coil wire 222. The cover module can securely bond and / or support the coil wire 222 to the heating block 240.

[0076] The cover module may have a module ring 245, which is a portion of the periphery of the coil wire 222.

[0077] Reference Figure 13 The module ring 245 can be a ring-shaped first module ring 245-1, which has the same outer diameter as the center of the hot block 240. (Refer to...) Figure 14 Module ring 245 can be a second annular module ring 245-2, the outer diameter of which is larger than the outer diameter of the center of the hot block 240. (Refer to...) Figure 15 The module ring 245 can be a hemispherical third module ring 245-3, which is attached to one end of the hot block 240. The third module ring 245-3 can represent a hemispherical shell portion.

[0078] Reference Figure 15 and Figure 16The cover module may include a rod-shaped module rod 246, which is attached to the heat block 240 (the coil shape formed by the coil wire 222) along its length. At least one end of the module rod 246 may be combined with a third module ring 245-3. In this case, the module rod 246 and the third module ring 245-3 may be formed as a single unit.

[0079] The module ring 245 and / or module rod 246 can securely support the coil wire 222 so that it does not fall off the hot block 240.

[0080] The direct catalytic combustion reaction coil 220 is preferably one of the platinum group metals, namely platinum (Pt), palladium (Pd), rhodium (Rh), iridium (Ir), and ruthenium (Ru), or an alloy of two or more platinum group metals. This platinum group metal monomer or alloy can provide a catalytic function at high temperatures to catalyze the combustion of combustible gases (in contact with the combustion gas) with oxygen. That is, the platinum group metal itself catalyzes the combustion of combustible gases, thus eliminating the need to form the nano-dispersed catalyst layer 126 of existing detection modules. Throughout the specification, "direct catalytic combustion reaction" can refer to the combustion reaction of combustible gases based on this catalytic function of the direct catalytic combustion reaction coil 220. "Direct catalytic combustion reaction" and "direct combustion reaction" can be used interchangeably. "Direct catalytic combustion reaction" can refer to the catalytic combustion reaction of the direct catalytic combustion reaction coil 220. "Direct catalytic combustion reaction" can be simply referred to as "direct combustion reaction." "Catalytic combustion reaction" can be referred to as "combustion reaction."

[0081] The wire diameter of the direct catalytic combustion reaction coil 220 is preferably 5–40 μm. The resistance of the direct catalytic combustion reaction coil 220 at room temperature is preferably 2–20 ohms. The coil diameter of the direct catalytic combustion reaction coil 220 is preferably 0.1–0.5 mm. The number of turns (windings) of the direct catalytic combustion reaction coil 220 is preferably 7–15 turns. This specification is compatible with existing contact combustion gas sensors.

[0082] The direct catalytic combustion reaction coil 220 needs to maintain a specific temperature to perform catalytic combustion reactions and other operations. This specific operating temperature is referred to as the "reaction operating temperature". Since the compensation element 260 needs to serve as a reference for the detection element 210, a specific reference temperature (hereinafter referred to as the "reference operating temperature") needs to be maintained. The reference operating temperature is preferably the same as the reaction operating temperature.

[0083] The direct catalytic combustion reaction coil 220 is powered (not shown) and releases heat (resistance heat) to maintain the reaction operating temperature of the direct catalytic combustion reaction coil 220 and / or the detection element 210 (especially, the hot block 240). Since the direct catalytic combustion reaction coil 220 undergoes a direct catalytic combustion reaction with the contact gas, it is preferable that at least the direct catalytic combustion reaction coil 220 maintains the reaction operating temperature. However, since a catalytic combustion reaction also occurs in the hot block 240, which is in contact with the outside like the direct catalytic combustion reaction coil 220, it is also more preferable that the hot block 240 maintains the reaction operating temperature.

[0084] The reaction operating temperature can be a specific temperature within the range of 300–350°C. The reaction operating temperature can be determined based on the type of gas to be detected.

[0085] Due to the heat of combustion of the contact gas in the direct catalytic combustion reaction based on the direct catalytic combustion reaction coil 220, the temperature of the direct catalytic combustion reaction coil 220 rises to above the reaction operating temperature.

[0086] Reference Figure 2 The heated mass 240 can be disposed inside the direct catalytic combustion reaction coil 220 to support the direct catalytic support combustion reaction coil 220. The heated mass 240 can be combined with a portion of the direct catalytic combustion reaction coil 220. The heated mass 240 can be cylindrical, but is not limited to this; it can be an ellipse or a polygonal prism.

[0087] The heat block 240 based on this embodiment can retain power source heat and combustion heat to reduce heat loss. In addition, it can provide a function equivalent to the propagation and diffusion of the direct catalytic combustion reaction of the direct catalytic combustion reaction coil 220.

[0088] Reference Figure 5 (a) The hot block 240 preferably has a plurality of pores 248 and / or internal channels 249 inside. The ventilation provided by the plurality of pores 248 and internal channels 249 can provide the effect of increasing the surface area, so that the combustion reaction of combustible gases can also occur inside the hot block 240. In particular, combustible gases can diffuse into the interior of the hot block 240 through the internal channels 249.

[0089] The heating element 240 is made of a ceramic material with relatively large particles, preferably lightweight while maintaining structural strength. The heating element 240 is preferably made of a material that can assist in the catalytic combustion reaction of the direct catalytic combustion reaction coil 220, helping to maintain the diffusion reaction and heat of catalytic combustion.

[0090] The hot mass 240 can be formed from a sintered body. The material of the hot mass 240 can be one of most metal oxides (oxides of Co, Ni, Mn, Cr, Ti, Cu, Sn, Fe, V, Ag, In, La, W, Zn, etc.), alumina, and silicon dioxide, or a composite ceramic composed of combinations of these. These materials exhibit excellent catalytic properties, far-infrared radiation characteristics, and long-term thermal stability. The metal oxides can undergo a catalytic combustion reaction with the contact gas, releasing heat of reaction. This heat of reaction further increases the resistance of the coil wire 222, which can further improve the sensitivity of gas detection.

[0091] The particle size of the sintered material for hot bulk 240 is suitable to be 0.1μm to 0.4mm. If it is less than 0.1μm, the air permeability will be poor, and if it is greater than 0.4mm, it may cause problems in molding.

[0092] To ensure the air permeability of the hot block 240, the material itself preferably has many pores and a large non-surface area. To ensure air permeability, organic binders or carbon materials can be mixed into the sintered material. The organic binders or carbon materials can generate air passages when they are discharged in the form of carbon dioxide and water vapor during the heat treatment process.

[0093] Reference Figure 5 , Figure 15 and Figure 16 The thermal block 240 can be divided into multiple modules. The thermal block 240 includes at least a basic module 242 and an adhesive module 244.

[0094] Reference Figure 15 and Figure 16 A coil wire 222 is disposed outside the base module 242, and an adhesive module 244 can combine the base module 242 and the coil wire 222. Although the inner diameter of the coil formed by the coil wire 222 is shown in the figure to be larger than the outer diameter of the base module 242, this is not a limitation. The outer diameter of the base module 242 and the inner diameter of the coil formed by the coil wire 222 may be substantially the same, or the inner diameter of the coil formed by the coil wire 222 may be larger than the outer diameter of the base module 242. This may occur due to manufacturing errors.

[0095] The base module 242 can serve as the foundation inside the hot block 240. The bonding module 244 can connect the base module 242 and the direct catalytic combustion reaction coil 220.

[0096] The base module 242 can be in the shape of a cylindrical rod. Depending on the material, the base module 242 can be a metal oxide rod, a ceramic rod, or a composite ceramic rod. The metal oxide rod can be formed from a material containing at least one of the following oxides: Co, Ni, Mn, Cr, Ti, Cu, Sn, Fe, V, Ag, In, La, W, and Zn. The ceramic rod can be formed from a material containing at least one of the following: alumina and silicon dioxide. The composite ceramic rod can be formed from a material containing both metal oxides and ceramic oxides.

[0097] The adhesive module 244 can be molded from a material containing transition metal oxides. The adhesive module 244 can also be molded from a material containing transition metal oxides and / or precious metal powders. Although precious metal powders have good reactivity with contact combustion gases, their high price makes them difficult to occupy a large proportion.

[0098] The bonding module 244 may also contain metal powder as a non-oxide. As a non-oxide, the metal powder can become an oxide during high-temperature heat treatment and has electrical insulation and catalytic properties.

[0099] Figure 5 (b) and Figure 5 (c) shows the case where the coil wire 222 is wound around the adhesive module 244. For example... Figure 5 (b) and Figure 5 As shown in (c), the two ends of the hot block 240 may not be perpendicular, but rather circular. Figure 5 (b) shows the adhesive module 244 generated when the viscosity of the slurry used as the material for the adhesive module 244 is high. Figure 5 (c) shows the adhesive module 244 generated when the viscosity of the slurry used as the material for the adhesive module 244 is low. The exposure ratio of the coil wire 222 can be adjusted by the viscosity of the slurry as described above.

[0100] Reference Figure 6 and Figure 7 The compensation element 260 may include a compensation element coil 270 and a compensation element surround 280. The compensation element coil 270 serves as a coil-type electrode wire, and the compensation element surround 280 surrounds the compensation element coil 270.

[0101] The compensating element coil 270 converts electrical energy into heat energy to maintain the compensating element 260 at a reference operating temperature. In fact, it is preferable that the compensating element coil 270 maintains the reference operating temperature.

[0102] In a contact combustion gas sensor equipped with an exposed coil detection element, a Wheatstone bridge circuit can be used to detect the increase in resistance of the detection element 210. The Wheatstone bridge circuit may include a direct catalytic combustion reaction coil 220 and a compensation element coil 270. The compensation element coil 270 preferably measures the same voltage (resistance) as the direct catalytic combustion reaction coil 220 in the absence of combustible gas. Therefore, while the compensation element coil 270 has a shape and specifications corresponding to the direct catalytic combustion reaction coil 220, it is not limited thereto. That is, when the compensation element coil 270 is in the absence of combustible gas at the operating temperature, it preferably has the same resistance value as the direct catalytic combustion reaction coil 220.

[0103] The compensating element coil 270 may include a coil conductor 272 and a coil-through conductor 274. The coil conductor 272 is helical in shape, and the coil-through conductor 274 connects one end of the coil conductor 272 to a power source and passes through the compensating element coil 280. The compensating element coil 280 may be cylindrical in shape and has a coil protrusion 282 formed in the through portion of the coil-through conductor 274. Due to the coil protrusion 282, the compensating element coil 280 may be a cylindrical shape with a handle.

[0104] The compensation element ring 280 is cylindrical in shape, and can be as follows: Figure 15 The detection element 210 has a shape with bulging ends. That is, the inner diameter of the two ends of the compensation element ring 280 can be larger than the inner diameter of the center.

[0105] The compensating element ring 280 can be cylindrical. To prevent venting, the distance (S0) between the cylindrical side of the coil wire 272 and the surface of the compensating element ring 280 is preferably the shortest among the distances (S0, S1, S2) between the coil wire 272 and the surface of the compensating element ring 280. If an existing commercial product is cut and ground, and observed under an electron microscope, the length S1 or S2 is 20-50 μm, which is 1 / 5 to 1 / 3 of the length S0 (100-150 μm). At this point, cracks and other damage are prone to occur at the S1 or S2 locations. These cracks form vents, allowing fuel gas, moisture, air, etc., to enter the compensating element ring 280. These intruders come into contact with the internal platinum coil, causing a catalytic combustion reaction. The catalytic combustion reaction increases the resistance of the platinum coil inside the compensating element, which may delay alarms or cause no alarm response even in the event of a fuel gas leak, potentially leading to a major accident. In particular, in hydrogen fuel gas with small molecules and unstable properties, it may trigger fatal malfunctions. The cylindrical shape with a handle of the present invention can prevent such damage and / or danger.

[0106] The compensation element ring 280 can isolate the compensation element coil 270 from the outside (external air). Therefore, the compensation element ring 280 is preferably formed from two or more pastes selected from alumina, silicon oxide, and metal oxides, and an inorganic binder. This is because when organic binders or carbon compounds are included, air or channels may be generated during sintering. Furthermore, to prevent the formation of voids or channels during sintering, the constituent material of the compensation element ring 280 is preferably formed from very fine nanoparticles. Therefore, the internal void size of the compensation element ring 280 is preferably 50 nm or less.

[0107] In existing contact combustion gas sensors, the compensation element has a shape and structure corresponding to the detection module 120, which does not have a detection module nano-dispersed catalyst layer 126. The compensation element maintains a certain temperature because it does not react with combustible gases and oxygen.

[0108] A perfect compensation element needs to maintain a temperature of 300–350°C throughout operation. Ideally, the operating temperature should remain unchanged under extreme environmental conditions, such as extreme variations in temperature and humidity, or prolonged use in environments with dust, toxic gases, or flammable gases. However, in practice, due to design errors or inappropriate material selection / processing, the temperature may fluctuate at the ends of the coil. Figure 6 The portion surrounding the through conductor 274 forms a ventilation channel, which is affected by temperature, humidity or flammable gas and thus changes in resistance.

[0109] In other words, it is very important to prevent cracks, pinholes, etc., from forming in the compensation element, especially at both ends.

[0110] Therefore, in this application, the thickness of both ends of the compensation element ring 280 is made thicker, forming a cylindrical shape with a handle, thereby eliminating the probability of generating gaps and / or air passages.

[0111] Furthermore, materials with a particle size of less than nm are used to form a dense structure. Even if conventional powder materials are used instead of nanomaterials in the primary ring (“Ring Core 285”), an ultrafine ceramic powder slurry with a particle size of less than 50 nm must be used in the second coating (“Ring Outer Surface 286”), and no carbon powder or organic binder is used. This allows for the filling and bonding of microcracks or pinholes formed on the compensation element ring. As a result, factors that have a major impact on sensitivity, long-term performance, and malfunctions can be improved.

[0112] Furthermore, organic binders or carbon materials used in existing technologies are not used, or if they are used, materials that do not create ventilation channels are employed. This is because when organic binders or carbon materials burn inside the compensation element ring 280 due to heat treatment during manufacturing processes or high heat during operation, their residues may cause pinholes or microcracks when discharged from the compensation element ring 280.

[0113] The following is for reference Figures 8-11 This describes a method for manufacturing a contact combustion gas sensor with an exposed coil detection element. (Reference) Figures 1 to 7 .

[0114] Reference Figure 8 According to an embodiment of the present invention, a method for manufacturing a contact combustion gas sensor with an exposed coil detection element can manufacture a base module 242 (S310). The base module 242 serves as an internal base among the multiple modules provided in the hot block 240. The hot block 240 supports a direct catalytic combustion reaction coil 220, which is a platinum-based coil in which at least a portion of the detection element 210 is in contact with external air and undergoes a direct catalytic combustion reaction with the contact gas.

[0115] Reference Figure 9 The basic module manufacturing step (S310) may include the step of manufacturing basic module slurry (S360).

[0116] An organic binder can be added to one of the following powders: metal oxide powder, ceramic powder, and composite ceramic powder, to manufacture a base module slurry. Metal oxide powder may refer to a powder composed of at least one of the following oxides: Co, Ni, Mn, Cr, Ti, Cu, Sn, Fe, V, Ag, In, La, W, and Zn. Ceramic powder may refer to a powder composed of at least one of the following: alumina and silicon dioxide. Composite ceramic powder may refer to a powder in which metal oxide powder and ceramic powder are mixed in an appropriate ratio. The parts described in this specification as consisting of specific elements are not limited thereto; unless otherwise specified, the aforementioned specific elements may include other elements.

[0117] The organic binder may be at least one of polyethylene glycol (PEG), polyvinyl alcohol (PVA), and carbon particles.

[0118] The ceramic composite powder preferably has an intermediate particle size of 0.1 to 10 μm to ensure air permeability.

[0119] The manufactured base module slurry can be formed into a specific shape (S365). The base module slurry can be formed inside the direct catalytic combustion reaction coil 220, or it can be separately manufactured into a rod shape on the outside and then inserted into the direct catalytic combustion reaction coil 220.

[0120] The slurry, which can be molded into a specific shape, can be dried (S370). Drying can be carried out at room temperature for about 1 hour.

[0121] The dried base module slurry can be subjected to low-temperature heat treatment (S375) to manufacture base module 242. The low-temperature heat treatment can be carried out at 150-350°C for about 1 hour.

[0122] Reference Figure 8 After manufacturing the base module 242, an adhesive module 244 (S320) connecting the base module 242 and the direct catalyst combustion reaction coil 220 can be manufactured.

[0123] Reference Figure 10 The manufacturing steps of the adhesive module 244 may include: adding a material with catalytic function to the base module slurry to manufacture the adhesive module slurry (S410). Thus, the adhesive module 244 enables catalytic combustion of the contact gas. The adhesive module slurry may be a paste made by adding at least one of CuO, ZnO, SnO2, TiO2, NiO, Co3O4, MnO2, AgO2, WO3, and precious metal powder to the base module slurry.

[0124] Materials with catalytic function can be at least transition metal oxides and precious metal powders. All transition metal oxides and precious metal powders with catalytic combustion properties (0-5% by weight relative to transition metal oxides) can be mixed to manufacture the adhesive module slurry. Regarding the adhesive module slurry, a composite powder material is manufactured by mixing two or more ceramic or metal oxide powders with co-catalytic properties and diameters of 0.1 μm to 0.4 mm in a certain weight ratio. A small amount of organic binder such as PEG or PVA, or carbon with a diameter of 0.1 μm to 10 μm, can be added to this composite powder material to manufacture the adhesive module slurry. Precious metal powders have higher catalytic function than transition metal oxides, but are more expensive. Since the catalytic combustion reaction in the adhesive module 244 accounts for a small proportion, a lower proportion of precious metal powder is acceptable.

[0125] The manufactured adhesive module slurry can be applied to the surface of the base module 242 (S415). Here, the shape of the hot block 240 can be finally completed. The adhesion, contact area, and self-strength of the base module 242 and the direct catalytic combustion reaction coil 220 can be adjusted in this step. In this step, the adhesive module slurry can be applied to the direct catalytic combustion reaction coil 220 so that the leakage of the direct catalytic combustion reaction coil 220 is more than 40% and less than 90%.

[0126] After the adhesive module slurry is shaped, it is dried (S420) and subjected to high-temperature heat treatment (S425) to manufacture the adhesive module 244.

[0127] It can be subjected to high-temperature heat treatment at 600–900℃ for 30 minutes. Through this high-temperature heat treatment, non-metallic organic matter is removed, and ordinary metals are reduced to oxides.

[0128] The first and second embodiments concerning the manufacture of the detection element 210 are as follows.

[0129] [Example 1]

[0130] A composite ceramic powder material was prepared by mixing alumina ceramics with a diameter of 0.1 μm to 10 μm in a weight ratio of 40, tin dioxide in a weight ratio of 30, and titanium dioxide in a weight ratio of 30 in a ball mill. A small amount of polyethylene glycol organic binder and 1–5 μm activated carbon powder were added to this composite ceramic powder material to create a base module slurry. At this point, 10 g of composite ceramic powder, 2 g of organic binder, and 1 g of activated carbon were mixed, and a small amount of water was added to adjust the viscosity. The viscosity was suitable when a small droplet of slurry could be formed on the tip of an injection needle. The base module slurry was then filled only inside a platinum-based coil.

[0131] After drying at room temperature for 1 hour, the basic module 242 is manufactured by performing a first-level heat treatment at 250°C for 1 hour in an air atmosphere.

[0132] Next, cobalt oxide powder material with a diameter of 0.1 mm or less, which has superior catalyst properties, is added to the base module slurry at a weight ratio of more than 50%, and then thoroughly mixed. Water is added to create a bonding module slurry with a viscosity adjusted to be lower than that of the base module slurry. The base module 242 is then coated with the bonding module slurry. Here, the hot block 240 is cylindrical, with a length the same as that of the coil, its bottom contacting the coil, and the other parts lightly contacting the inner surface of the direct catalytic combustion reaction coil 220 (especially the "coil wire 222").

[0133] After drying at room temperature for 1 hour, as a second heat treatment, the element is placed in an electric furnace and heat-treated in air at 800°C for 30 minutes to complete the detection element 210.

[0134] [Example 2]

[0135] A composite powder material was prepared by mixing alumina ceramics with a diameter of 0.1 μm to 10 μm at a weight ratio of 40, tin dioxide at a weight ratio of 30, and nickel oxide at a weight ratio of 30 in a ball mill. A small amount of liquid polyvinyl acetate organic binder was added to this composite powder material to create a base module slurry. At this stage, 10 g of the composite powder and 3 g of the organic binder were mixed, and a small amount of water was added to adjust the viscosity. The viscosity was suitable when a small droplet of slurry could be formed on the tip of an injection needle.

[0136] The process involves applying the prepared base module slurry only to the inside of the direct catalytic combustion reaction coil 220. Holding one side of the direct catalytic combustion reaction coil 220, immerse it once in the slurry solution and then slowly lift it to the outside. Only fill the coil with the slurry. Then, in a horizontal position, dry it at 100°C for 1 hour, followed by a primary heat treatment at 200°C in air for 1 hour.

[0137] Next, manganese oxide powder with a diameter of less than 0.1 μm, which has superior catalyst properties, is added to the primary composite powder material at a weight ratio of 50%, and then thoroughly mixed. Subsequent procedures are the same as in Example 1.

[0138] Reference Figure 8 The manufacturing method of the contact combustion gas sensor with exposed coil detection element may further include a manufacturing step (S330) of compensation element ring 280, wherein the compensation element ring 280 surrounds the compensation element coil 270, which serves as a coil type electrode wire in the compensation element 260.

[0139] Reference Figure 11 The manufacturing steps of the compensation element ring 280 may include a ring core module slurry manufacturing step (S410). The particle size of the composite ceramic powder is preferably below 50 nanometers.

[0140] To manufacture the core module slurry, a composite ceramic powder containing metal oxide powder and ceramic powder can be prepared. The metal oxide powder can be at least one of the oxides Ti, Cu, Sn, Fe, V, Ag, In, La, W, and Zn. The ceramic powder can be at least one of alumina and silicon dioxide.

[0141] Inorganic binders are added to composite ceramic powder, followed by water or alcohol, to create a core module slurry. Organic alcohols are readily volatile and leave no residue, posing no problems in their use.

[0142] After manufacturing the coil core module paste, the coil core module paste is applied to the compensating element coil 270 (S455), and then dried and subjected to low-temperature heat treatment (S460) to form the coil core 285. Preferably, the low-temperature heat treatment is carried out at 150 to 350°C for no more than 1 hour. The coil core 285 can be circular or elliptical in shape.

[0143] It can manufacture a ring outer surface module slurry (S465) using the same material as the ring core module slurry, but with a higher viscosity.

[0144] A module paste for the outer surface of the ring core 285 can be applied to form a cylindrical shape with a handle (S470). After drying and high-temperature heat treatment (S475), the outer surface 286 of the ring is formed, thereby manufacturing the compensation element ring 280. Preferably, the high-temperature heat treatment is performed at 600 to 900°C for 30 minutes.

[0145] The particle size of the core module slurry and the outer surface module slurry of the ring is preferably less than 50 nm. This is to prevent cracks or pinholes from forming on the outer surface 286 of the ring.

[0146] An example of manufacturing the compensation element ring 280 is shown below.

[0147] [Example 3]

[0148] Alumina powder with a particle size of less than 50 nm (40 by weight), titanium oxide powder with a particle size of less than 50 nm (30 by weight), and zinc oxide powder with a particle size of less than 50 nm (30 by weight) are weighed and mixed together. Water and 10% by weight of copper oxide inorganic binder with a particle size of less than 50 nm are further added to this mixture to complete the ring core module slurry. A drop of the completed ring core module slurry is applied to a compensation element coil 270 of the same specifications as the direct catalytic combustion reaction coil 220 used on the detection element 210 using an injection needle to create a circular primary ring (ring core 285). Afterwards, a primary heat treatment at 300°C is performed, followed by drying at room temperature.

[0149] The same slurry as the first stage (coil core module slurry) is used, but the viscosity is higher due to air drying. A second-stage shape adjustment coating is applied, using up to 10 fine brushes to apply the slurry thickly to both ends of the coil and the heating wires at both ends. After the coil shape approaches a cylindrical shape with a handle, it is dried at room temperature. Then, a second-stage firing process is performed in an electric furnace at 800°C to complete the compensation element.

[0150] Furthermore, while the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above. Various modifications can be made by those skilled in the art without departing from the spirit of the invention as claimed in the claims. Such modifications should not be construed as different from the technical concept or prospect of the present invention.

[0151] <Explanation of Figure Markers>

[0152] 210: Detection element; 220: Direct catalyst combustion reaction coil

[0153] 222: Coil wire; 224: Connecting wire

[0154] 240: Thermal Block 242: Basic Module

[0155] 244: Adhesive module 248: Air pores

[0156] 260: Compensation element 270: Compensation element coil

[0157] 272: Coil wire; 274: Loop-through wire

[0158] 280: Compensating element ring; 282: Ring protrusion.

[0159] 285: Core of the ring; 286: Outer surface of the ring

Claims

1. A contact combustion gas sensor with an exposed coil detection element, comprising the detection element and a compensation element, wherein the detection element reacts with contact gas, and the compensation element does not react with contact gas, characterized in that, The above-mentioned detection elements include: A coil conductor, wherein the coil conductor is coil-shaped, and the exposed portion of the coil conductor that is in direct contact with external air undergoes a direct catalytic combustion reaction with the contacting combustion gas in the external air; and A heating element is disposed inside the aforementioned coil wire, and a portion of it is combined with the aforementioned coil wire to support it. The coil wires mentioned above are made of platinum-based materials.

2. The contact combustion gas sensor with an exposed coil detection element according to claim 1, characterized in that, The exposed portion of the aforementioned coil conductor is 40% to 90% of the surface area of ​​the aforementioned coil conductor.

3. The contact combustion gas sensor with an exposed coil detection element according to claim 1, characterized in that, The aforementioned hot block body includes a cover module that covers a portion of the aforementioned coil wires. The aforementioned cover module is at least one of a module ring and a module rod. The module ring is a portion of the area surrounding the aforementioned coil wire, and the module rod is rod-shaped and attached to the aforementioned hot block along the length direction of the aforementioned hot block.

4. The contact combustion gas sensor with an exposed coil detection element according to claim 1, characterized in that, The aforementioned coil conductor is one of the platinum group metals, namely platinum, palladium, rhodium, iridium, and ruthenium, or an alloy of two or more of the aforementioned platinum group metals.

5. The contact combustion gas sensor with an exposed coil detection element according to claim 1, characterized in that, It also includes a direct catalytic combustion reaction coil, which has the aforementioned coil wires. The aforementioned direct catalytic combustion reaction coil releases heat when powered to maintain a preset reaction operating temperature; the aforementioned direct catalytic combustion reaction in contact with the combustion gas generates heat of combustion, raising the temperature above the reference operating temperature of the aforementioned compensation element. The aforementioned hot block retains the aforementioned heat from the power source and the aforementioned heat from combustion to reduce heat loss. The hot block contains pores, which react with the aforementioned contact gas to undergo catalytic combustion and generate additional heat.

6. The contact combustion gas sensor with an exposed coil detection element according to claim 5, characterized in that, The aforementioned thermal block is divided into multiple modules. The aforementioned modules include a base module and an adhesive module. The base module serves as the internal foundation, and the adhesive module connects the base module and the direct catalyst combustion reaction coil.

7. The contact combustion gas sensor with an exposed coil detection element according to claim 6, characterized in that, The aforementioned basic module is one of the following: a metal oxide rod containing at least one of the following oxides: Co, Ni, Mn, Cr, Ti, Cu, Sn, Fe, V, Ag, In, La, W, and Zn; a ceramic rod containing at least one of the following alumina and silicon dioxide; and a composite ceramic rod containing the aforementioned metal oxide and the aforementioned ceramic oxide. The aforementioned adhesive module contains at least the aforementioned transition metal oxide and precious metal powder.

8. The contact combustion gas sensor with an exposed coil detection element according to claim 5, characterized in that, The aforementioned compensation element comprises a compensation element coil and a compensation element surround, wherein the compensation element coil serves as a coil-type electrode wire, and the compensation element surround encloses the compensation element coil. The aforementioned compensation element coil converts electrical energy into heat energy to achieve the aforementioned reference operating temperature. The aforementioned compensation element coil isolates the compensation element coil from the external air. The aforementioned compensation element ring has no gaps or connecting channels inside.

9. The contact combustion gas sensor with an exposed coil detection element according to claim 8, characterized in that, The aforementioned compensation element coil comprises a coil conductor and a through conductor in a surrounding coil. The coil conductor is helical in shape, and the through conductor in the surrounding coil connects one end of the coil conductor to the power supply and passes through the surrounding coil of the compensation element. The aforementioned compensation element has a cylindrical ring and a ring protrusion formed in the portion through which the through wire passes. The inner diameters at both ends of the aforementioned compensation element's ring are larger than the inner diameter at the center.

10. The contact combustion gas sensor with a coil-exposed detection element according to claim 9, characterized in that, The aforementioned compensation element ring is formed from two or more slurries selected from alumina, silicon oxide, and metal oxides, along with an inorganic binder.

11. A method for manufacturing a contact combustion type gas sensor having a coil-exposed detection element, the contact combustion type gas sensor comprising the detection element and a compensation element, wherein the detection element reacts with contact gas, and the compensation element does not react with contact gas, characterized in that, The basic module manufacturing steps are as follows: the basic module serves as the internal foundation among the multiple modules of the hot block; the hot block supports a direct catalytic combustion reaction coil; the direct catalytic combustion reaction coil is a platinum coil that is in contact with external air and undergoes a direct catalytic combustion reaction with the contact gas in the above-mentioned detection element. The bonding module manufacturing step, wherein the bonding module is used to connect the aforementioned base module and the aforementioned direct catalyst combustion reaction coil; and The manufacturing step of the compensation element ring, which is used to surround the compensation element coil, which serves as a coil-type electrode wire in the aforementioned compensation element. The aforementioned compensation element is a cylindrical ring with protrusions at both ends.

12. The method for manufacturing a contact combustion gas sensor with an exposed coil detection element according to claim 11, characterized in that, The manufacturing steps for the above basic modules include: The basic module slurry manufacturing step involves adding an organic binder or carbon powder to one of the following powders: an oxidized metal oxide powder containing at least one of Co, Ni, Mn, Cr, Ti, Cu, Sn, Fe, V, Ag, In, La, W, and Zn; a ceramic powder containing at least one of alumina and silica; and a composite ceramic powder containing the aforementioned metal oxide powder and ceramic powder. The drying and low-temperature heat treatment steps involve molding the above-mentioned basic module slurry into a specific shape, and then drying and performing low-temperature heat treatment on the molded basic module slurry.

13. The method for manufacturing a contact combustion gas sensor with an exposed coil detection element according to claim 12, characterized in that, The manufacturing steps of the above-mentioned adhesive module include: The bonding module slurry manufacturing step involves adding at least one of the following: CuO, ZnO, SnO2, TiO2, NiO, Co3O4, MnO2, AgO2, WO3, and precious metal powders, which enable catalytic combustion of the contact gas, to the aforementioned base module slurry; and manufacturing the bonding module slurry. After the above-mentioned adhesive module slurry is applied to the surface of the above-mentioned base module, it is dried and subjected to high-temperature heat treatment.

14. The method for manufacturing a contact combustion gas sensor with an exposed coil detection element according to claim 11, characterized in that, The manufacturing steps for the aforementioned compensation element ring include: Manufacturing steps for the core module slurry; The core forming step involves applying the core module slurry to the compensation element coil, followed by drying and low-temperature heat treatment to form a circular or elliptical core. The outer surface module slurry manufacturing step of the ring is as follows: the outer surface module slurry is made of the same material as the core module slurry of the ring, but with a higher viscosity; and The outer surface of the ring is formed by applying the outer surface module paste of the ring core to the outer surface of the ring core to form a cylindrical shape with protrusions at both ends, followed by drying and high-temperature heat treatment to form the outer surface of the ring. The above-mentioned core module slurry contains: A composite ceramic powder comprising metal oxide powder and ceramic powder, wherein the metal oxide powder is at least one of oxidized Ti, Cu, Sn and Zn, and the ceramic powder comprises at least one of alumina and silicon dioxide; Inorganic adhesives; and One of water and alcohol, The particle size of each component material in the above-mentioned outer surface module slurry is below 50 nm.

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