Heater and heating component

Abstract

The present application provides a heater and a heating member, in which the reliability is high in an environment in which a cordierite substrate is not easily cracked and thermal fluctuation is large. The heater (100) includes a first cordierite substrate (10), a glass portion (20) provided on the first cordierite substrate (10), and an electrothermal portion (30) embedded in the glass portion (20). The glass portion (20) contains MgO, Al2O3, and SiO2.

Description

Technical Field

[0001] This invention relates to heaters and heating components. Background Technology

[0002] The demand for reducing harmful components (HC, NOx, CO) in automotive exhaust is increasing. In particular, the purification of NOx emitted from diesel engines is a significant issue. As a countermeasure for NOx purification, a technology known as the urea SCR system is commonly used. In the urea SCR system, NH3, a NOx reducing agent, is generated through the thermal decomposition and hydrolysis of urea. For efficient thermal decomposition and hydrolysis of urea, it needs to be heated efficiently. However, with the increase in engine efficiency, exhaust gas temperature decreases, and it is also low immediately after engine start-up. At low exhaust gas temperatures, even when urea is injected into the exhaust gas, the decomposition reaction is difficult to occur, thus failing to fully generate NH3. Furthermore, when the injected urea collides with the inner wall of the exhaust pipe, if the inner wall temperature is low, the urea cannot be completely decomposed into NH3, becoming intermediate solid precipitates that accumulate. As a result, this may obstruct exhaust gas flow or hinder the mixing of the generated NH3 with the exhaust gas due to changes in exhaust gas flow. Therefore, a heater is being developed that can efficiently heat exhaust gas and maintain the inner wall of the exhaust pipe at a high temperature.

[0003] Furthermore, in battery electric vehicles (BEVs) and fuel cell vehicles (FCVs) that lack a heat source from an internal combustion engine, as well as plug-in hybrid vehicles (PHVs and PHEVs) that frequently stop and start their internal combustion engines, heating load can impact driving distance. Therefore, improving heating efficiency is an important issue. Consequently, heaters are being developed that efficiently warm specific spaces within a short period of time, rather than heating the entire vehicle interior.

[0004] Furthermore, to achieve carbon neutrality, synthetic fuels are being developed that synthesize hydrogen produced through the electrolysis of water and CO2 emitted from power plants, factories, etc. However, the manufacturing process of synthetic fuels requires heating. This manufacturing process can be easily secured by a heat source when it is carried out in a location where heat from factory exhaust can be supplied; however, in locations without a heat source, electricity must be used for heating. The electricity is preferably generated from renewable energy sources that do not emit CO2 during the manufacturing process, and the heating efficiency of the heaters is also required to be improved.

[0005] A heater that embeds a conductor in a substrate with a small heat capacity or has conductors arranged between the substrates is one of the powerful heating mechanisms used in various applications as described above.

[0006] For example, Patent Document 1 discloses a heater comprising: a plate-shaped first heater substrate; heating wires arranged in parallel circuits on a first surface of the first heater substrate; electrodes connected to the heating wires to energize them; and a plate-shaped cover substrate covering the first surface of the first heater substrate, the heating wires, and the electrodes on a second side. In this heater, the first heater substrate and / or the cover substrate comprises Si3N4 or Al2O3, and the heating wires comprise at least one metal selected from the group consisting of WC, TiN, TaC, ZrN, MoSi2, Pt, Ru, and W.

[0007] Patent document 2 proposes a heater comprising: an insulating substrate composed of alumina ceramic, silicon nitride ceramic, etc., and a resistive element embedded in the insulating substrate, the resistive element comprising a first conductor particle mainly composed of tungsten and a second conductor particle mainly composed of molybdenum.

[0008] Patent document 3 discloses a mixer for an exhaust gas purification device, which includes: an outer cylinder made of insulating ceramic such as alumina, silicon nitride, cordierite, etc.; fins made of insulating ceramic disposed on the inner side of the outer cylinder; and an electric heating part embedded in at least a portion of the outer cylinder and / or the fins.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: Japanese Patent Application Publication No. 2017-182890

[0012] Patent Document 2: Japanese Patent No. 5748918

[0013] Patent Document 3: Japanese Patent Application Publication No. 2020-197208 Summary of the Invention

[0014] For heaters used in the applications described above, the requirement is that they can heat up quickly and efficiently, and have high reliability in environments with large thermal fluctuations.

[0015] In the aforementioned prior art, the silicon nitride (Si3N4) used in the substrate of the heater is approximately 3 g / cm³. 3 Due to its low density, it is lightweight. Furthermore, silicon nitride has a density of approximately 3 × 10⁻⁶. -6Silicon nitride (SNH4OH) exhibits a low coefficient of thermal expansion and a high Young's modulus of approximately 300 GPa, along with a high flexural strength of approximately 800 MPa, ensuring high reliability even in environments with significant thermal fluctuations. However, SNH4OH is expensive, and the sintering temperature needs to be above 1700°C, resulting in high manufacturing costs.

[0016] In addition, alumina (Al2O3) is an inexpensive material and a widely used representative ceramic; however, it has a viscosity of approximately 4 g / cm³. 3 Due to its high density, it is relatively heavy. Additionally, alumina has a density of approximately 8 × 10⁻⁶. -6 The high thermal expansion coefficient ( / K) and high Young's modulus (approximately 350 GPa) mean that in environments with large thermal fluctuations, thermal stress increases, making it difficult to ensure reliability.

[0017] On the other hand, cordierite has a content of approximately 2.5 g / cm³. 3 Due to its low density, it is lightweight. Additionally, cordierite has a density of approximately 1.6 × 10⁻⁶. -6 Cordierite has a low coefficient of thermal expansion (C / K) and a low Young's modulus of approximately 150 GPa. Therefore, even in environments with large thermal fluctuations, thermal stress can be kept to a low level, thus ensuring high reliability.

[0018] However, when a conductor with a high thermal expansion rate is embedded in a cordierite substrate made of cordierite with a low thermal expansion rate, or when a conductor is arranged between the cordierite substrates, there is a problem that the cordierite substrate may crack due to the difference in thermal expansion rates.

[0019] The present invention was carried out to solve the problems described above, and its purpose is to provide a heater and heating element with high reliability in environments where cordierite substrates are not prone to cracking and where thermal fluctuations are large.

[0020] The inventors of this invention conducted in-depth research and discovered that by embedding the heating element (conductor) in the glass part and placing it in the cordierite substrate, it is possible to suppress cracking in the cordierite substrate due to the difference between the thermal expansion coefficient of the cordierite substrate and the thermal expansion coefficient of the heating element, thus completing this invention.

[0021] That is, the present invention is a heater comprising: a first cordierite substrate; a glass portion disposed on the first cordierite substrate; and an electric heating portion embedded in the glass portion, the glass portion comprising MgO, Al2O3 and SiO2.

[0022] Additionally, the present invention is a heating component comprising: a cylindrical component; the aforementioned heater disposed along at least a portion of the inner circumferential surface of the cylindrical component; and an insulating material disposed between the cylindrical component and the heater, wherein the heating elements of a plurality of heaters are electrically connected to a power source in series or in parallel.

[0023] Invention Effects

[0024] According to the present invention, a heater and heating element with high reliability can be provided that are not prone to cracking in cordierite substrates and are subjected to large thermal fluctuations. Attached Figure Description

[0025] Figure 1 This is a top view of the heater according to an embodiment of the present invention.

[0026] Figure 2 yes Figure 1 A cross-sectional view of line A-A'.

[0027] Figure 3 This is a top view of a heater according to another embodiment of the present invention.

[0028] Figure 4 yes Figure 3 A cross-sectional view of line B-B'.

[0029] Figure 5 This is a cross-sectional view of the heating component according to an embodiment of the present invention.

[0030] Figure 6 This is a top view showing the heating elements of multiple heaters according to an embodiment of the present invention connected in series with a power source.

[0031] Figure 7 This is a top view showing the electric heating elements of multiple heaters according to an embodiment of the present invention connected in parallel to a power source.

[0032] Figure 8 This is a cross-sectional view of the heating component according to an embodiment of the present invention, which is used to heat a reducing agent precursor to generate a reducing agent.

[0033] Symbol Explanation

[0034] 10… First cordierite substrate, 20… Glass part, 30… Heating part, 40… Second cordierite substrate, 50… Terminal, 60… Brazing filler metal, 70… Sealing part, 100, 200… Heater, 300… Cylindrical part, 400… Insulating material, 500… Bolt, 600… Nozzle, 1000, 2000… Heating element. Detailed Implementation

[0035] Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. The present invention is not limited to the following embodiments, and it should be understood that embodiments obtained by appropriate modifications or improvements to the following embodiments based on ordinary knowledge of those skilled in the art, without departing from the spirit of the present invention, also fall within the scope of the present invention.

[0036] (1) Heater

[0037] Figure 1 This is a top view of the heater according to an embodiment of the present invention. Figure 2 This is a cross-sectional view of the heater along line A-A'.

[0038] like Figure 1 and Figure 2 As shown, the heater 100 includes: a first cordierite substrate 10; a glass portion 20 disposed on the first cordierite substrate 10; and an electric heating portion 30 embedded in the glass portion 20. It should be noted that... Figure 1 In the diagram, the dashed line indicates the position of the heating element 30 embedded in the glass portion 20. The glass portion 20 has the same coefficient of thermal expansion as the first cordierite substrate 10. Therefore, by embedding the heating element 30 within the glass portion 20 and placing it on the first cordierite substrate 10, and ensuring that the first cordierite substrate 10 and the heating element 30 do not directly contact each other, cracking of the first cordierite substrate 10 can be suppressed. Thus, the reliability of the heater 100 in environments with large thermal fluctuations can be improved.

[0039] The first cordierite substrate 10 is a substrate with cordierite (2MgO·2Al2O3·5SiO2) as the main component.

[0040] Here, in this specification, "main component" refers to a component that accounts for more than 50% by mass, preferably more than 90% by mass, of all components.

[0041] The first cordierite substrate 10 preferably consists of 90% by mass or more cordierite phase, 5% by mass or less crystalline phase comprising andalusite and / or spinel, and the balance being a glassy phase. With such a composition, properties such as thermal expansion coefficient and Young's modulus can be controlled within the desired range.

[0042] Here, the mass percentage of each phase in the first cordierite substrate 10 is calculated as follows. First, the mass ratios of cordierite, andalusite, spinel, and glass are varied and mixed to prepare multiple samples, and calibration lines for the peak values ​​of X-ray diffraction are pre-established. Next, the peak values ​​are determined using X-ray diffraction of the first cordierite substrate 10, and the mass ratio (mass percentage) of each phase in the first cordierite substrate 10 is calculated based on the calibration lines.

[0043] The open porosity of the first cordierite substrate 10 is not particularly limited, but is preferably 10% or less, more preferably 5% or less. By controlling the open porosity to this range, when the heater 100 is used in an environment where liquids such as reducing agent precursors (e.g., urea solution) are attached, it is possible to prevent liquids from penetrating into the interior of the first cordierite substrate 10.

[0044] Here, the open porosity of the first cordierite substrate 10 can be determined using existing experimental methods (Archimedes method, JIS R1634:1998). The open porosity of the first cordierite substrate 10 can be controlled by reducing the particle size of the raw material powder or by adding sintering aids.

[0045] The coefficient of thermal expansion (coefficient of thermal expansion) of the first cordierite substrate 10 is not particularly limited, but is preferably 1.5 × 10⁻⁶. -6 ~2.0×10 -6 / K. If the thermal expansion rate is within this range, the thermal stress in environments with large thermal fluctuations can be reduced, thus improving the reliability of heater 100.

[0046] Here, the thermal expansion coefficient of the first cordierite substrate 10 can be determined according to JIS R1618:2002.

[0047] The Young's modulus of the first cordierite substrate 10 is not particularly limited, but is preferably 160 GPa or less. A Young's modulus within this range reduces thermal stress in environments with large thermal fluctuations, thus improving the reliability of the heater 100. Furthermore, from the viewpoint of suppressing deformation and damage to the heater 100 caused by vibration, the Young's modulus of the first cordierite substrate 10 is preferably 100 GPa or more.

[0048] Here, the Young's modulus of the first cordierite substrate 10 can be calculated as follows: For the first cordierite substrate 10, the bending strength is measured according to the four-point bending strength test method shown in JIS R1601:2008, and a stress-deformation curve is plotted based on the test results. The slope of the obtained stress-deformation curve is calculated, and this slope is set as the Young's modulus.

[0049] The glass portion 20 contains MgO, Al2O3, and SiO2. MgO, Al2O3, and SiO2 are components of cordierite. Therefore, by including MgO, Al2O3, and SiO2 in the glass portion 20, the difference in the coefficient of thermal expansion between the glass portion 20 and the first cordierite substrate 10 can be reduced. As a result, thermal stress in environments with large thermal fluctuations can be reduced, thus improving the reliability of the heater 100. In addition, the adhesion between the glass portion 20 and the first cordierite substrate 10 can also be improved.

[0050] The glass portion 20 may contain cordierite (2MgO·2Al2O3·5SiO2). By including cordierite in the glass portion 20, the thermal expansion coefficient of the glass portion 20 can be made close to that of the first cordierite substrate 10. As a result, thermal stress in environments with large thermal fluctuations can be reduced, thus improving the reliability of the heater 100. In addition, the adhesion of the glass portion 20 to the first cordierite substrate 10 can also be improved.

[0051] There are no particular limitations on the method of including cordierite in the glass section 20. For example, waste generated during the production of the first cordierite substrate 10 can be added to the raw materials of the glass section 20.

[0052] The glass portion 20 is preferably composed of 30-40% by mass of cordierite phase, less than 2% by mass of crystalline phase containing andalusite and / or spinel, and the balance being a glass phase. With such a composition, properties such as the coefficient of thermal expansion can be controlled within the desired range.

[0053] Here, the mass percentage of each phase in the glass section 20 is calculated as follows. First, the mass ratios of cordierite, andalusite, spinel, and glass are varied and mixed to prepare multiple samples, and calibration lines for the peak values ​​of X-ray diffraction are pre-established. Next, the peak values ​​are determined using X-ray diffraction of the glass section 20, and the mass ratio (mass percentage) of each phase in the glass section 20 is calculated based on the calibration lines.

[0054] The coefficient of thermal expansion (coefficient of thermal expansion) of the glass portion 20 is not particularly limited, but is preferably greater than 1.6 × 10⁻⁶. -6 / K and less than 3.0×10 -6 / K, more preferably exceeding 1.6×10 -6 / K and is 2.5×10 -6 Below / K, further preference is given to those exceeding 1.6×10. -6 / K and is 2.0×10 -6 / K or less. If the thermal expansion coefficient of the glass portion 20 is within the range described above, the difference in thermal expansion coefficient between the glass portion 20 and the first cordierite substrate 10 can be reduced. As a result, the thermal stress in environments with large thermal fluctuations can be reduced, and therefore, the reliability of the heater 100 is improved.

[0055] The heating element 30 is composed of a conductor that heats up when electricity is applied. There are no particular limitations on the conductor; any metal or alloy known in the art can be used. Preferably, the conductor contains Mo and / or W. Using such a conductor reduces the difference in thermal expansion coefficients between the heating element 30 and the glass element 20, and also improves its compatibility with the embedded glass element 20. Other usable conductors include Ni-Cr alloys and Fe-Cr-Al alloys.

[0056] The thermal expansion coefficient of the heating element 30 is not particularly limited, but is preferably greater than 1.6 × 10⁻⁶. -6 / K and less than 6.0×10 -6 / K, more preferably exceeding 1.6×10 -6 / K and is 5.5×10 -6 / K or less. If the thermal expansion coefficient of the heating element 30 is within the range described above, the difference in thermal expansion coefficient between the heating element 30 and the glass element 20 can be reduced. As a result, the thermal stress in environments with large thermal fluctuations can be reduced, thus improving the reliability of the heater 100. For example, Mo has a thermal expansion coefficient of approximately 5.0 × 10⁻⁶ K. -6 / K thermal expansion coefficient. In addition, by using a conductive composite obtained by combining Mo powder and / or W powder with glass powder with low thermal expansion, the thermal expansion coefficient of the heating element 30 can also be controlled by adjusting the proportion and type of each component.

[0057] The shape of the heating element 30 is not particularly limited; it can be various shapes such as linear, plate-like, or sheet-like. It should be noted that... Figure 1 and Figure 2 The example shown is a case where a wire-shaped heating element 30 is formed.

[0058] A second cordierite substrate may be further provided on the glass portion 20 on which the heating element 30 is embedded.

[0059] Here, a top view of the heater, which also includes a second cordierite substrate, is shown. Figure 3 The cross-sectional diagram of the B-B' line of the heater is shown in the figure. Figure 4 .

[0060] like Figure 3 and Figure 4 As shown, the heater 200 includes: a first cordierite substrate 10; a glass portion 20 disposed on the first cordierite substrate 10; an electric heating portion 30 embedded in the glass portion 20; and a second cordierite substrate 40 disposed on the glass portion 20. It should be noted that... Figure 4 In the diagram, the dashed line indicates the position of the heating element 30 embedded in the glass portion 20. In this heater 200 structure, the heating element 30 is embedded in the glass portion 20 and positioned between the first cordierite substrate 10 and the second cordierite substrate 40, ensuring that the first and second cordierite substrates 10 and 40 do not directly contact the heating element 30. Therefore, cracking of the first and second cordierite substrates 10 and 40 can be suppressed. Consequently, the reliability of the heater 200 in environments with large thermal fluctuations can be improved.

[0061] The second cordierite substrate 40 is a substrate with cordierite (2MgO·2Al2O3·5SiO2) as the main component, just like the first cordierite substrate 10. It can be the same substrate as the first cordierite substrate 10.

[0062] The second cordierite substrate 40 preferably consists of 90% by mass or more cordierite phase, 5% by mass or less of a crystalline phase containing andalusite and / or spinel, and the balance being a glassy phase. With this composition, properties such as thermal expansion coefficient and Young's modulus can be controlled within the desired range. The mass percentage of each phase in the second cordierite substrate 40 can be calculated in the same manner as the mass percentage of each phase in the first cordierite substrate 10.

[0063] like Figures 1-4 As shown, heaters 100 and 200 may further include terminals 50 that are connected to the heating element 30 via brazing filler metal 60. With this configuration, the heating element 30 can be easily electrically connected to an external power source (not shown).

[0064] Terminal 50 is made of a conductor capable of conducting electricity. There are no particular limitations on the conductor used for terminal 50; any metal or alloy known in the art can be used. Preferably, the conductor used for terminal 50 contains Fe, Ni, and Co. For example, an iron-nickel-cobalt alloy can be used as such a material.

[0065] It should be noted that the conductor used for terminal 50 can be made of the same conductor as the heating element 30, or it can be made of a different conductor than the heating element 30.

[0066] The coefficient of thermal expansion (coefficient of thermal expansion) of the conductor constituting terminal 50 is not particularly limited, but is preferably greater than 1.6 × 10⁻⁶. -6 / K and less than 6.0×10 -6 / K, more preferably exceeding 3.0×10 -6 / K and less than 6.0×10 -6 / K. If the thermal expansion coefficient of the conductor constituting terminal 50 is within the range described above, then especially Figure 3 and Figure 4 In the heater 200 shown, the difference in thermal expansion coefficients between the second cordierite substrate 40 and the conductor constituting the terminal 50 can be reduced. As a result, thermal stress in environments with large thermal fluctuations can be reduced, thus improving the reliability of the heater 200. For example, the iron-nickel-cobalt alloy has a thermal expansion coefficient of approximately 5.0 × 10⁻⁶. -6 / K thermal expansion coefficient.

[0067] Figure 3 and Figure 4In the heater 200 shown, the terminal 50 is preferably inserted into a through hole disposed in the second cordierite substrate 40. With this configuration, the heating element 30 can be easily electrically connected to an external power source (not shown).

[0068] The solder 60 is the material used to join the heating element 30 and the terminal 50. There are no particular limitations on the solder 60; any suitable material can be selected depending on the type of heating element 30 and terminal 50. For example, if the heating element 30 uses a conductor containing Mo and / or W, and the terminal 50 uses a conductor containing Fe, Ni, and Co, then the solder 60 preferably contains Ag, Ti, and Cu. If the solder 60 contains such components, a proper connection can be achieved without affecting the heating element 30 and terminal 50.

[0069] Here, an experiment was conducted where the heating element 30 used a conductor made of Mo (Mo wire), and the terminal 50 used a conductor made of iron-nickel-cobalt alloy (iron-nickel-cobalt alloy pin). The heating element 30 and the terminal 50 were actually joined using three types of solder 60 (66Ag-8Ti-Cu, 65Ag-15Pd-Cu, and Ni-Cr-P). The results showed that 66Ag-8Ti-Cu could effectively bond the Mo wire and the iron-nickel-cobalt alloy pin at approximately 900°C. In contrast, 65Ag-15Pd-Cu bonded the Mo wire and the iron-nickel-cobalt alloy pin at 900°C, but Pd evaporation was observed. Furthermore, a reaction was observed between Ni-Cr-P and the Mo wire. Therefore, it can be concluded that when the heating element 30 uses Mo wire and the terminal 50 uses an iron-nickel-cobalt alloy pin, 66Ag-8Ti-Cu is the most suitable solder 60.

[0070] like Figures 1-4 As shown, heaters 100 and 200 may further include a sealing portion 70 provided at the boundary surface between the terminal 50 and the glass portion 20 or the second cordierite substrate 40. Specifically, in heater 100, a sealing portion 70 may be provided at the boundary surface between the terminal 50 and the glass portion 20. Additionally, in heater 200, a sealing portion 70 may be provided at the boundary surface between the terminal 50 and the second cordierite substrate 40. By adopting such a configuration, the intrusion of liquids, air, etc., from this boundary can be suppressed, thus improving the reliability of heaters 100 and 200.

[0071] The material constituting the sealing part 70 is not particularly limited, and any sealing material known in the art can be used. Among them, glass is preferred as the material constituting the sealing part 70.

[0072] Furthermore, the sealing portion 70 (glass) preferably contains SiO2 and B2O3. If the sealing portion 70 contains such components, it can suppress cracking of the sealing portion 70 and its surrounding components (glass portion 20, second cordierite substrate 40) due to its low coefficient of thermal expansion.

[0073] The coefficient of thermal expansion of the glass constituting the sealing part 70 is not particularly limited, but is preferably greater than 1.6 × 10⁻⁶. -6 / K and less than 6.0×10 -6 / K, more preferably exceeding 2.0×10 -6 / K and less than 4.0×10 -6 / K. If the thermal expansion coefficient of the glass constituting the sealing portion 70 is within the range described above, then in heater 100, the difference in thermal expansion coefficient between the glass portion 20 and the conductor constituting the terminal 50 and the glass constituting the sealing portion 70 becomes smaller, and in heater 200, the difference in thermal expansion coefficient between the second cordierite substrate 40 and the conductor constituting the terminal 50 and the glass constituting the sealing portion 70 becomes smaller. As a result, thermal stress in environments with large thermal fluctuations can be reduced, thus improving the reliability of heaters 100 and 200.

[0074] With the configuration described above, heaters 100 and 200 are less prone to cracking in cordierite substrates (first cordierite substrate 10 and second cordierite substrate 40) and have high reliability in environments with large thermal fluctuations, thus enabling their use in various applications.

[0075] For example, heaters 100 and 200 are useful for heating the exhaust gas in the exhaust gas mixer used to mix urea and exhaust gas in a urea SCR system of a diesel engine. Additionally, they are useful for maintaining a high temperature on the inner wall of the cylindrical component (exhaust pipe) constituting the exhaust gas mixer in this urea SCR system, and for preventing the accumulation of solid precipitates formed when urea collides with the inner wall. In the urea SCR system, by injecting urea water into the exhaust gas heated by heaters 100 and 200, ammonia (NH3) can be generated as a NOx reducing agent.

[0076] In addition, heaters 100 and 200 are also useful for use as heating equipment in electric vehicles, fuel cell vehicles and plug-in hybrid vehicles, as well as heating mechanisms in the manufacturing process of synthetic fuels.

[0077] Heaters 100 and 200 can be manufactured according to methods known in the art.

[0078] For example, heater 100 can be manufactured as follows.

[0079] First, a molding material containing cordierite raw material powder is molded and then sintered to produce a first cordierite substrate 10. The molding method is not particularly limited and can include extrusion molding, casting molding, etc. Alternatively, the first cordierite substrate 10 can be produced by machining a sintered body with a specified shape.

[0080] Next, the heating element 30 is sandwiched between two glass sheets that form the glass element 20 and disposed on the first cordierite substrate 10 to form a laminated structure. At this time, the glass sheet on the surface side is provided with an opening for connecting the heating element 30 and the terminal 50 by means of brazing filler metal 60.

[0081] Next, the laminated structure is heated and pressurized to achieve integration. At this point, the glass sheets are integrated to form the glass section 20, and the heating element 30 is embedded in the glass section 20. The heating and pressurization conditions can be appropriately set according to the type of glass sheet used, and there are no particular limitations.

[0082] Next, the terminal 50 is positioned on the heating element 30 exposed at the opening of the surface-side glass plate using the brazing filler metal 60, and then heated to form a bond. The heating conditions can be set appropriately depending on the type of brazing filler metal 60 used, and are not particularly limited.

[0083] Finally, a sealing material is applied to the surface of the glass part 20 and the boundary between the terminal 50 and the glass part 20. Then, a heat treatment is performed to form the sealing part 70, thus completing the heater 100. The heating conditions can be set appropriately according to the type of sealing material used, and there are no particular limitations.

[0084] Alternatively, heater 200 can be manufactured as follows.

[0085] First, a molding material containing cordierite raw material powder is molded and then sintered to produce a first cordierite substrate 10 and a second cordierite substrate 40.

[0086] Next, the heating element 30 is sandwiched between two glass sheets that form the glass element 20, and then positioned between the first cordierite substrate 10 and the second cordierite substrate 40 to form a laminated structure. At this time, the glass sheets on the second cordierite substrate 40 side are provided with openings for connecting the heating element 30 and the terminal 50 using brazing filler metal 60.

[0087] Next, in order to improve the adhesion between the first cordierite substrate 10, the second cordierite substrate 40, and the glass sheet with the heating element 30 sandwiched in, the laminated structure is pressurized and heated simultaneously to achieve integration.

[0088] Next, the terminal 50 is placed on the heating part 30 exposed at the opening of the glass sheet on the second cordierite substrate 40 and the glass sheet on the second cordierite substrate 40 side by means of brazing filler metal 60, and then heated to make them bond.

[0089] Finally, a sealing material is applied to the surface of the second cordierite substrate 40, at the boundary between the terminal 50 and the second cordierite substrate 40, and then a heat treatment is performed to form the sealing part 70, thus completing the heater 200.

[0090] (2) Heating components

[0091] Figure 5 This is a cross-sectional view of the heating component according to an embodiment of the present invention. It should be noted that... Figure 5 It is a cross-sectional view in a direction perpendicular to the axial direction of the cylindrical component 300 constituting the heating component 1000.

[0092] like Figure 5 As shown, the heating element 1000 includes: a cylindrical component 300; a plurality of heaters 100 and 200 arranged along at least a portion of the inner circumferential surface of the cylindrical component 300; and an insulating material 400 disposed between the cylindrical component 300 and the heaters 100 and 200. By employing such a structure, the interior of the cylindrical component 300 can be heated.

[0093] As for the cylindrical component 300, there are no particular limitations; it can have a uniform diameter in the axial direction, or it can have a reduced diameter and / or expanded diameter in the axial direction.

[0094] The material of the cylindrical component 300 is not particularly limited, but from a manufacturing point of view, a metal is preferred. Examples of metals that can be used include stainless steel, titanium alloy, copper alloy, aluminum alloy, and brass. Among these, stainless steel is preferred due to its high durability, reliability, and low cost.

[0095] The thickness of the cylindrical component 300 is not particularly limited, but is preferably 0.1 mm or more, more preferably 0.3 mm or more, and even more preferably 0.5 mm or more. By ensuring the thickness of the cylindrical component 300 is 0.1 mm or more, durability and reliability can be ensured. Furthermore, the thickness of the cylindrical component 300 is preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less. By ensuring the thickness of the cylindrical component 300 is 10 mm or less, lightweighting can be achieved.

[0096] As for the insulating material 400, there are no particular limitations, and fiber gaskets made of silicon nitride, aluminum oxide, etc. can be used.

[0097] The thickness of the insulating material 400 is sufficient to ensure insulation; there are no special limitations.

[0098] Multiple heaters 100 and 200 are arranged along at least a portion of the inner circumferential surface of the cylindrical component 300. There is no particular limitation on the method of fixing the heaters 100 and 200; for example, they can be fixed to the inner circumferential surface of the cylindrical component 300 using fixing clamps such as bolts 500.

[0099] The multiple heaters 100 and 200 are configured such that the heating element 30 can be electrically connected to a power source in series or in parallel. By adopting such a configuration, a voltage is applied from the power source to cause the multiple heaters 100 and 200 to heat up, thereby heating the interior of the cylindrical component 300.

[0100] Here, a top view showing the electric heating units 30 of multiple heaters 100 and 200 connected in series to a power source is shown. Figure 6 Additionally, a top view showing the electric heating units 30 of multiple heaters 100 and 200 connected in parallel to a power source is provided. Figure 7 It should be explained that... Figure 6 and Figure 7 In the image, the three heaters 100 are shown from a top viewpoint for easy understanding. Additionally, the dashed lines indicate the locations of the embedded heating elements 30.

[0101] Figure 6 In this configuration, the heating elements 30 of multiple heaters 100 and 200 are connected in series. One end of the series-connected heating elements 30 is connected to a power source, and the other end is connected to a ground wire (e.g., cylindrical component 300). Figure 7 In the process, the heating elements 30 of multiple heaters 100 and 200 are connected in parallel. One end of each heating element 30 is connected to a power source, and the other end is connected to a ground wire (e.g., cylindrical component 300).

[0102] The applied voltage from the power source is not particularly limited, but is preferably 60V or less. If the voltage is within this range, no special insulation is required. However, considering the heating efficiency of heaters 100 and 200, the applied voltage is preferably 12V or more.

[0103] The heating component according to embodiments of the present invention is suitable for use in a urea SCR system for a diesel engine. Specifically, the heating component according to embodiments of the present invention can be used to: maintain a high temperature on the inner wall surface of the cylindrical component 300 constituting an exhaust gas mixer that mixes a reducing agent precursor (e.g., urea solution) and exhaust gas; suppress the accumulation of solid precipitates that form intermediates when the reducing agent precursor collides with the inner wall surface; and heat the reducing agent precursor to generate a reducing agent (e.g., ammonia).

[0104] Here, a cross-sectional view of the heating component used to heat the reducing agent precursor to generate the reducing agent is shown. Figure 8 It should be explained that... Figure 8It is a cross-sectional view in a direction perpendicular to the axial direction of the cylindrical component 300 constituting the heating component 2000.

[0105] like Figure 8 As shown, the heating element 2000 also includes a nozzle 600 disposed on at least a portion of the cylindrical component 300, capable of spraying a reducing agent precursor onto the inner circumferential surface of the cylindrical component 300. Furthermore, multiple heaters 100 and 200 are disposed on the inner circumferential surface of the cylindrical component 300 from which the reducing agent precursor is sprayed from the nozzle 600. The cylindrical component 300 is, in fact, the exhaust pipe of a diesel engine. With this configuration, the exhaust gas flowing through the cylindrical component 300 (exhaust pipe) can be heated by the multiple heaters 100 and 200, and the reducing agent precursor can be sprayed onto the heated exhaust gas to generate a reducing agent. Moreover, even if the reducing agent precursor sprayed from the nozzle 600 collides with the multiple heaters 100 and 200, the reducing agent precursor evaporates immediately, thus suppressing the accumulation of deposits formed due to the decomposition of the reducing agent precursor.

[0106] The heating element 2000 is preferably composed of multiple heaters 100, 200 whose heating elements 30 are connected in parallel. Specifically, it is preferable that one end of each heating element 30 of the multiple heaters 100, 200 is electrically connected to a power source, and the other end is electrically connected to a ground wire (e.g., the cylindrical component 300). Furthermore, the applied voltage from the power source is preferably 60V or less. With this configuration, the reducing agent precursor can be rapidly and efficiently heated to generate the reducing agent, and the accumulation of intermediates on the inner wall surface of the cylindrical component 300 is suppressed.

Claims

1. A heater, wherein, It comprises: a first cordierite substrate; a glass portion disposed on the first cordierite substrate; and an electrothermal portion embedded in the glass portion. The glass portion contains MgO, Al2O3, and SiO2. The first cordierite substrate is composed of more than 90% by mass cordierite phase, less than 5% by mass crystalline phase containing andalusite and / or spinel, and the balance being a glassy phase.

2. The heater according to claim 1, wherein, It also includes a second cordierite substrate, which is disposed on the glass portion.

3. The heater according to claim 2, wherein, It also has a terminal that is connected to the heating element by means of a solder.

4. The heater according to claim 3, wherein, The terminal is inserted into a through hole provided in the second cordierite substrate.

5. The heater according to claim 3 or 4, wherein, It also includes a sealing portion disposed on the boundary surface between the terminal and the glass portion or the second cordierite substrate.

6. The heater according to claim 3, wherein, The glass portion contains cordierite.

7. The heater according to claim 3, wherein, The glass portion consists of 30-40% by mass cordierite phase, less than 2% by mass crystalline phase containing andalusite and / or spinel, and the balance being a glass phase.

8. The heater according to claim 3, wherein, The second cordierite substrate is composed of more than 90% by mass cordierite phase, less than 5% by mass crystalline phase containing andalusite and / or spinel, and the balance being a glassy phase.

9. The heater according to claim 3, wherein, The thermal expansion coefficient of the glass portion exceeds 1.6 × 10⁻⁶. -6 / K and less than 3.0×10 -6 / K.

10. The heater according to claim 3, wherein, The heating element is made of a conductor containing Mo and / or W.

11. The heater according to claim 3, wherein, The terminals have a thermal expansion coefficient exceeding 1.6 × 10⁻⁶. -6 / K and less than 6.0×10 -6 The conductor is composed of / K.

12. The heater according to claim 11, wherein, The thermal expansion coefficient of the conductor constituting the terminal exceeds 3.0 × 10⁻⁶. -6 / K and less than 6.0×10 -6 / K.

13. The heater according to claim 5, wherein, The sealing part has a thermal expansion coefficient exceeding 1.6 × 10⁻⁶. -6 / K and less than 6.0×10 -6 / K glass composition.

14. The heater according to claim 13, wherein, The coefficient of thermal expansion of the glass constituting the sealing portion exceeds 2.0 × 10⁻⁶. -6 / K and less than 4.0×10 -6 / K.

15. The heater according to claim 3, wherein, The terminals contain Fe, Ni and Co.

16. The heater according to claim 5, wherein, The sealing part contains SiO2 and B2O3.

17. The heater according to claim 3, wherein, The brazing filler metal contains Ag, Ti, and Cu.

18. The heater according to claim 4, wherein, The heater is used to heat the exhaust gas.

19. A heating element, wherein, have: Cylindrical components; A plurality of heaters, wherein the heaters are the heaters according to any one of claims 1 to 18, the plurality of heaters being arranged along at least a portion of the inner circumferential surface of the cylindrical member; as well as An insulating material is disposed between the cylindrical component and the heater. The heating elements of the plurality of heaters can be electrically connected to a power source in series or in parallel.

20. The heating component according to claim 19, used to heat the reducing agent precursor to generate a reducing agent, wherein, It also includes a nozzle disposed on at least a portion of the cylindrical component, capable of spraying the reducing agent precursor onto the inner circumferential surface of the cylindrical component. The heater is disposed on the inner circumferential surface of the cylindrical component from which the reducing agent precursor is injected from the nozzle. The cylindrical component is the exhaust pipe of a diesel engine.

21. The heating element according to claim 20, wherein, One end of the heating element of the heater is electrically connected to the power source, and the other end is electrically connected to the cylindrical component. The applied voltage from the power source is below 60V.

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