Gas piping system for high-temperature fuel cells

Abstract

The present invention relates to a gas piping device (10) that serves to conduct high-temperature gas between high-temperature fuel cell stacks (SOFC stacks). According to the present invention, the gas piping device (10) has a pipe body (11) made of a ceramic material for electrical insulation of potential at the axial end of the pipe body (11), and further has coupling means (13) for mounting and / or sealing between the pipe body (11) and the connection area (12), each coupled on one side to the pipe body (11) via an extension that intersects the pipe body (11) in the axial direction and on the other side to the connection area (12), wherein the coupling means (13) and the connection area (12) are made of the same metal material.

Description

【Technical Field】 【0001】 The present invention relates to a gas piping device for conducting a gas having a high temperature between at least two fuel cell stacks, and also to a gas piping mechanism and a high-temperature fuel cell system having the same. 【0002】 The gas piping device according to the present invention is applied to a facility structure for regenerative energy generation by a solid oxide fuel cell (SOFC) that operates at a high temperature between 500°C and 1000°C, or for hydrogen recovery by a solid oxide electrolysis cell (SOEC). Accordingly, the high operating temperature, and the temperature fluctuations during shutdown and startup when the operation is stopped, are special requirements related to facility technology. 【Background Art】 【0003】 Facility technology for a solid oxide fuel cell system (SOFC system) is known in which a fuel cell stack is insulated from peripheral equipment of the system's facility technology by an electrically insulating coating of the stack components or the surrounding housing. Based on the technical limitations of coating technology or layer thickness, the maximum achievable insulation characteristics of such a design are limited. 【0004】 In a conventional structure of an SOFC system, fuel cell stacks are usually wired electrically in series to operate with each other. In the above-described conventional system structure in which fuel cell stacks are wired in series, even if the insulation characteristics of the insulation coating are limited, it is usually sufficient. This is because it only needs to withstand the maximum potential difference between the ends of each stack or the output voltage of the fuel cell stack. 【0005】 A gas piping device for conducting a gas having a high temperature between at least two fuel cell stacks is known, for example, from US Patent Application Publication No. 2014 / 147766A1 and US Patent Application Publication No. 2015 / 357669A1. 【Prior Art Documents】 [Patent Documents] 【0006】 [Patent Document 1] U.S. Patent Application Publication No. 2014 / 147766A1 [Patent Document 2] U.S. Patent Application Publication No. 2015 / 357669A1 [Overview of the Initiative] [Problems that the invention aims to solve] 【0007】 The object of the present invention is to provide a technology suitable for equipment structures for high-temperature fuel cells that provides improved or alternative electrical insulation in the mechanism of a fuel cell stack, particularly with respect to equipment technology for connecting between individual fuel cell stacks in the mechanism. 【0008】 Another object of the present invention is to provide a technology suitable for equipment structures for high-temperature fuel cells that enables alternative electrical wiring and / or mechanisms of fuel cell stacks with alternative electrical wiring, with respect to equipment technology for connecting between individual fuel cell stacks of a system. [Means for solving the problem] 【0009】 The above-mentioned problems are solved by a gas piping device having the constituent elements of claim 1. Building upon this, a further advanced technical solution forms the basis of a gas piping mechanism or high-temperature fuel cell system described in claim 10 or 12, which includes the constituent elements of the gas piping device and takes advantage of its benefits. Other constituent elements and details of the present invention will become apparent from the dependent claims, the detailed description of the invention, and the drawings. 【0010】 The gas piping system according to the present invention serves to conduct high-temperature gas for a high-temperature fuel cell, and comprises a piping body and a through passage that extends through the piping body to guide the flow of high-temperature gas along the axial direction. 【0011】 According to the present invention, the pipe body is made from a ceramic material for electrical insulation of the potential at the axial end of the pipe body. 【0012】 Thus, the present invention is intended for the first time to be an electrically insulating body as an intermediate component in high-temperature resistant gas piping for fuel cells or electrolytic cells that have high operating temperatures, particularly in SOFC systems and SOEC systems. 【0013】 Furthermore, this invention is the first to envision a ceramic body as an intermediate component in gas piping, which is typically made primarily from high-temperature resistant steel to withstand the high operating temperatures of gases. 【0014】 An advantage of the present invention is that the high-temperature resistant ceramic piping body of the gas piping system according to the present invention effectively blocks conductivity along the gas piping section, which relies on the conductivity of the metal material in the piping section. This blocks short-circuit currents and parasitic currents that may occur through the piping between each fuel cell in any mechanism and wiring. 【0015】 Since the insulation of the ceramic piping body of the gas piping system according to the present invention is placed on peripheral equipment for the equipment technology for guiding media, which is mainly made from steel, yet another advantage of the present invention is that it basically enables series wiring of high-temperature fuel cell stacks that must receive a gas flow. 【0016】 Another advantage of the present invention is that the material thickness of the ceramic piping body of the gas piping system according to the present invention provides significantly higher insulation properties compared to conventional insulating coatings around or on the outer surface of the fuel cell stack. 【0017】 In a preferred embodiment of the present invention, the ceramic material from which the pipe body is fabricated may be metal-coated aluminum oxide, and preferably the pipe body has a metal coating on axially separated surface areas as a base for material bonding techniques. Thus, despite the ceramic material, effective bonding with metal components is possible by brazing. Since the metal-coated surfaces are separated, no axial conductivity occurs through the metal coating of the pipe body. The ceramic material from which the pipe body is fabricated is particularly preferably Al2O3. 【0018】 In a preferred embodiment of the present invention, the gas piping system may have a connection area located at the axial end of the pipe body, having a pipe connection surface that surrounds a through passage toward the axial end of the gas piping system. In this way, an improved connection coupling of adjacent pipe areas to the pipe body is provided. 【0019】 In a preferred embodiment of the present invention, the connection area may be made from a metal material, particularly from a high-temperature resistant steel, preferably from an austenitic chromium-nickel steel alloy having temperature resistance to over 1000°C, preferably up to 1100°C, or from Ni200. Preferably, the connection area made from Ni200 is directly connected to the pipe body. In this case, the pipe body is formed particularly from Al2O3. Since both of these materials (Ni200 and Al2O3) have similar coefficients of thermal expansion, it is not thought that any further means of connection would be necessary. 【0020】 According to the present invention, the gas piping system further comprises coupling means for mounting and / or sealing between the pipe body and the connection area, each coupling to the pipe body on one side via an extension intersecting the pipe body axially with the pipe body and to the connection area on the other side via an extension intersecting the connection area axially with the pipe body. The axial intersection allows for compensation between the different coefficients of thermal expansion between the ceramic of the pipe body and the various metals of the coupling means and the connection area. 【0021】 The bonding means and the connection area are intended to be made of the same metallic material, particularly preferably Ni200. Ni200 is a non-alloy nickel having a nickel content of at least 99.2%, and thus Ni200 is a pure metal and not an alloy. Therefore, if the connection area and the bonding means are made of the same material, they jointly form a single member. According to the present invention, this can be interpreted as meaning that the bonding means is not necessary and only the connection area is sufficient, which is preferably directly bonded to the pipe body. At this time, the pipe body is particularly formed from Al2O3. Such a configuration of the bonding area or the connection area and the pipe body further avoids the disadvantages of thermal expansion. 【0022】 In a preferred embodiment of the present invention, the bonding means may be made of a metallic material, preferably a nickel-iron-cobalt alloy having a low coefficient of expansion of less than 7.0 x 10 -6 1 / K, or from Ni200. The small thermal expansion of the nickel-iron-cobalt alloy has the advantage of keeping the material stress resulting from the different thermal expansions between the components as low as possible at the bonding location with the ceramic material. On the other hand, when the bonding means is formed from Ni200, the bonding means can be integrally formed with the connection area, which is also formed from Ni200. 【0023】 In a preferred embodiment of the present invention, the bonding means may be configured in a ring shape and surrounds the circumference of the pipe body and / or one of the circumferences of the connection area for a radial friction joining type and / or form-fitting joining type of connection between the bonding means and the pipe body and / or between the bonding means and the connection area. In this way, mechanical attachment at the component boundary is achieved by the bonding means. 【0024】 In a preferred embodiment of the present invention, the pipe body can include a metal coating injected into a ceramic material in a circumferential surface area, and the coupling means and / or the connection area can be joined by a brazing material to the circumferentially metal-coated surface for a material-joining type of connection between the coupling means and / or the connection area and the pipe body. In this way, by the coupling means, in addition to additional mounting, the sealing of the gas pipe device under the resulting operating pressure is also improved. The brazing material is preferably composed of gold, so that it does not corrode. Therefore, if the coupling means and the connection area are made of the same material and are integrally formed therewith, both are joined to the metal circumferential surface by the brazing material, and at this time the brazing material is preferably formed of gold. 【0025】 Since the gas pipe device forms the smallest unit of the present invention that can be handled and traded and is accordingly protected and then delivered, in the following, the gas pipe mechanism and the system structure to be described later are yet another technical related matter of the present invention in which the advantages of the gas pipe device described above are utilized. 【0026】 In a further developed embodiment of the present invention, the gas pipe mechanism may be equipped with at least one gas pipe device according to the present invention for guiding the high-temperature gas of a high-temperature fuel cell. Further, the gas pipe mechanism has a pipe area configured in a tubular shape for guiding the flow of the gas axially along the gas pipe mechanism; at least one gas pipe device is arranged between two of these pipe areas for electrical conductivity interruption along the gas pipe mechanism. 【0027】 In a preferred embodiment of the present invention, the gas pipe mechanism can have a compensation area with a tubular outer casing configured to be flexible axially for compensating for the forces acting axially and / or the angular offsets in the gas pipe mechanism as a result of the different thermal expansions of the pipe area and the gas pipe device. In this way, the service life of the gas pipe device, particularly of the ceramic pipe body, is prolonged. 【0028】 In a more advanced embodiment of the present invention, a high-temperature fuel cell system may have a plurality of fuel cell stacks, at least one gas piping mechanism for guiding anode supply gas and / or anode exhaust gas, and at least one gas piping device according to the present invention. In this case, the gas piping mechanism includes at least one gas piping device between at least two of the fuel cell stacks. 【0029】 In a preferred embodiment of the present invention, at least one gas piping mechanism may have branches connected to a fuel cell stack for parallel supply or discharge of high-temperature gas; the gas piping mechanism may have gas piping devices between each branch. 【0030】 In a preferred embodiment of the present invention, at least two of the fuel cell stacks may be arranged in a vertical-vertical orientation in the stack direction of the fuel cells, and at least one gas piping mechanism may pass alongside the fuel cell stacks substantially parallel to the stack direction. 【0031】 In a preferred embodiment of the present invention, a plurality of fuel cell stacks may be stacked in a tower configuration in the direction of the stack of fuel cells, with each end of the fuel cell stacks being wired in series with respect to each other and electrically connected; at least one gas piping mechanism may have one of the gas piping devices positioned between each branch of the gas piping mechanism to one of the fuel cell stacks for insulation of the gas piping mechanism between the different potentials of the fuel cell stacks which are wired in series along the stacking direction and stacked in a tower configuration. 【0032】 In a preferred embodiment of the present invention, the branching section may be integrated into the end plate of the fuel cell stack for parallel supply or discharge of high-temperature gas to or from the fuel cell stack; the end plate extends through the cross section of at least one gas piping mechanism to connect the integrated branching section to the gas piping mechanism. Accordingly, a space-saving configuration of the fuel cell stack and its piping is created, which allows for a denser arrangement of multiple towers of this type of fuel cell stack in the SOFC system. 【0033】 Other advantages, constituent elements, and details of the present invention will become apparent from the following description, which describes in detail one embodiment with reference to the drawings. [Brief explanation of the drawing] 【0034】 [Figure 1] Figure 1 is a perspective view showing an embodiment of a gas piping system. [Figure 2] Figure 2 is an axial longitudinal cross-sectional view showing the same embodiment of the gas piping system. [Figure 3] Figure 3 shows a high-temperature fuel cell system, including an enlarged view of a gas piping mechanism in which gas piping equipment is used as a component. [Modes for carrying out the invention] 【0035】 Figure 1 shows an embodiment of a gas piping system 10 having multiple components, and this perspective view shows the gas piping system 10 assembled in the sense of a single module based on the embodiment. 【0036】 As shown in the longitudinal cross-sectional view of the gas piping system 10 in Figure 2, the basic module of the illustrated embodiment specifically includes a cylindrical pipe body 11 with a cylindrical through passage 15 formed inside, two adjacent flange-shaped connection areas 12, and two annular coupling means 13 surrounding the pipe body 11 and the connection areas 12. According to the present invention, the connection areas 12 and the coupling means 13 may preferably be configured as a common member made from the same material. In that case, the through passage 15 will be in contact with the common member consisting of the connection areas 12 and the coupling means 13. It is also convenient that the coupling means 13 be omitted and the connection areas be formed from Ni200. 【0037】 The pipe body 11 is a major component of a possible embodiment of the gas piping system 10, which has been reduced to a minimum number of components. The pipe body 11 is preferably configured in a rotationally symmetric shape with a constant inner diameter for the through passage 15. The outer sheath surface is preferably stepped to form two circumferential surface areas 16 that are separated from each other toward the axial end of the pipe body 11, serving as a housing and contact surface for the annular coupling means 13. Since the pipe body 11 is made of ceramic material, it is virtually nonconductive and serves as an insulator between each adjacent piping section of the gas piping. 【0038】 The ceramic material consists of aluminum oxide with the designation AK97M, which is characterized by high electrical resistance and good metallability. This allows the material to form hard brazed bonds with other metal components when its surface is metallized. 【0039】 Based on these characteristics, a metal coating is injected into the circumferential surface area 16 of the pipe body 11 to a predetermined surface depth, using aluminum oxide. Since the central part of the pipe body 11 in the axial direction does not have a metal coating, the axial insulation properties are maintained. 【0040】 The connection area 12 has a flange-like end face and is adjacent to the end face of the axial end of the pipe body 11. Preferably, the inner diameter of the rotationally symmetric connection area 12 matches the through passage 15 in order to uniformly continue it. The stepped outer casing surface has a connection surface 14 whose diameter is reduced axially outward. Such optional shaping allows the connection surface 14 to be connected to an adjacent pipe, for example, by fitting or press fitting. On the side axially opposite to this, a portion of the stepped outer casing surface with a relatively large radius has a circumference equal to the adjacent circumferential surface area 16 of the pipe body 11, at least up to an axial stopper, and is intended to accommodate an annular coupling means 13 and serve as its contact surface. 【0041】 The metal material for connection area 12 is an austenitic chromium-nickel steel alloy with the standard designation X15CrNiSi25-21 or material number 1.4841. This alloy is characterized by its corrosion resistance and temperature resistance up to approximately 1,150°C, and is therefore particularly suitable for the equipment structure of the SOFC system. It is preferable that other components of the gas piping mechanism, such as piping areas and compensation areas, are also made from the same steel alloy. 【0042】 The metal material of the bonding means 13 is a nickel-iron-cobalt alloy with the standard designation NiCo29-18 or material number 1.3981. This alloy has a viscosity of approximately 5.0-6.5 x 10 depending on the temperature range. -6 It is characterized by having an extremely low thermal expansion coefficient of 1 / K, and such a thermal expansion coefficient allows for a good approximation of the low expansion coefficient of the ceramic of the pipe body 11, and possibly the metal-coated material. 【0043】 In the described embodiment, the modules of the gas piping system 10 have not only friction-type or shape-type connections by fitting between the coupling means 13, the pipe body 11, and the connection area 12, but also material-type connections. For example, the surface of the circumferential area 16 of the pipe body 11 is inlaid with a metal coating of ceramic or aluminum oxide. Between the metal-coated circumferential area 16 and the annular coupling means 13 made of metal coating, a brazed joint made of hard solder is applied for additional attachment and sealing (not shown in detail). Between the annular coupling means 13 made of metal coating and the connection area 12 made of steel alloy, a brazed joint or welded joint is also applied for additional attachment and sealing (not shown in detail). 【0044】 Thus, in the embodiments described, the coupling means 13 provides not only mechanical attachment but also sealing between the pipe body 11 and the connection area 12. In alternative embodiments, the coupling means 13 can satisfy only one of these two characteristics, while the other characteristic is satisfied by additional attachment or sealing means. 【0045】 Figure 3 shows a diagram of the SOFC system, or high-temperature fuel cell system 30, on the right side, where fuel cell stacks 31 are stacked in a tower configuration, one above the other, in the same stacking direction, as are the fuel cells inside the fuel cell stacks 31, and are electrically connected to each other by being wired in series. Parallel to this, two gas piping mechanisms 20 run alongside the fuel cell stacks 31, parallel to the stacking direction. 【0046】 One of the two gas piping mechanisms 20 supplies anode supply gas, preheated to a high temperature, to all fuel cell stacks 31 in parallel. The other of the two gas piping mechanisms 20 discharges anode exhaust gas, which has a high reaction temperature, to all fuel cell stacks 31 in parallel. At this time, each fuel cell stack 31 has an end plate 32 configured as a medium distribution plate, which integrates a passage that serves as a branching point for the anode supply gas from one gas piping mechanism 20 and a passage that serves as a branching point for the anode exhaust gas to the other gas piping mechanism 20. The end plate 32 extends so as to enter the cross-section of the gas piping mechanism 20, establishing a branch connection of the internal passage of the end plate 32 to the gas flow in the gas piping mechanism 20. Based on the metallic material of the end plates 32 of the fuel cell stack 31 and the components of the gas piping mechanism 20, without electrical insulation in the embodiment of the system design described, a short-circuit current would propagate through the gas piping mechanism 20 along the entire stack direction of the tower-shaped mechanism based on the differing potentials of the fuel cell stacks 31 wired in series. However, complete electrical isolation of peripheral equipment between each fuel cell stack 31 wired in series is achieved based on a number of electrically insulating gas piping devices 10 arranged along the gas piping mechanism 20 between each branch of the gas flow to each fuel cell stack 31, i.e., between each interface with the end plates 32 that guide the medium. 【0047】 As shown on the left side of Figure 3, the gas piping mechanism 20, in combination with the gas piping device 10, preferably includes an additional component. For example, in addition to the gas piping device 10 and the piping section 22 that forms a piping section adjacent to the end plate 32 that guides the medium, a compensation section 21 is positioned between them. The compensation section 21 has an axially flexible sheath surface, for example in the form of a bellows, to compensate for forces arising from material stresses based on the different thermal expansion behavior of the materials of each component. In this way, the compensation section 21 prevents the ceramic material of the piping section 11, which has relatively brittle material properties, from being exposed to harmful axial forces and / or angular offsets as a result of the expansion of the piping section 22, which is made of a steel alloy that undergoes much stronger thermal expansion. (Other possible items) (Item 1) A gas piping system (10) for conducting high-temperature gas in a high-temperature fuel cell, The pipe has a main body (11) and a through passage (15) that extends through the main body (11) to guide the flow of high-temperature gas along the axial direction. A gas piping system comprising a pipe body (11) made of a ceramic material for electrical insulation of potential at the axial end of the pipe body (11), and further comprising coupling means (13) for mounting and / or sealing between the pipe body (11) and a connection area (12), wherein the coupling means (13) and the connection area (12) are made of the same metal material. (Item 2) The ceramic material from which the pipe body (11) is manufactured is metal-coated aluminum oxide, as described in item 1, for the gas piping device (10). (Item 3) The gas piping apparatus (10) according to item 2, wherein the piping body (11) has a metal coating on surface areas separated from each other in the axial direction, serving as a base for material bonding techniques. (Item 4) A gas piping device (10) according to any one of items 1 to 3, further comprising a connection area (12) located at the axial end of the piping body (11), having a piping connection surface (14) that surrounds the through passage (15) toward the axial end of the gas piping device (10). (Item 5) The gas piping device (10) according to item 4, wherein the connection area (12) is made from a metal material, preferably from an austenitic chromium-nickel steel alloy having a temperature resistance of more than 1000°C, preferably up to 1100°C, or from Ni200. (Item 6) The gas piping apparatus (10) described in item 5, wherein the coupling means (13) and the connection area (12) are made of Ni200. (Item 7) The coupling means (13) is made of a metal material, preferably 7.0 x 10 -6 A gas piping apparatus (10) described in any one of items 1 to 6, made from a nickel-iron-cobalt alloy having a low coefficient of thermal expansion of less than 1 / K, or from Ni200. (Item 8) The gas piping apparatus (10) according to any one of items 5 to 7, wherein the coupling means (13) is configured in an annular shape and surrounds the circumference of the pipe body (11) and / or the circumference of one of the connection area (12) for radial friction joint and / or shape joint coupling between the coupling means (13) and the pipe body (11), and / or between the coupling means (13) and the connection area (12). (Item 9) The gas piping apparatus (10) according to any one of items 1 to 8, wherein the pipe body (11) includes a metal coating injected into the ceramic material in a circumferential surface area (16), and the coupling means (13) and / or the connection area (12) are joined to the metal-coated circumferential surface (16) by brazing material for a material-bonding type of coupling between the coupling means (13) and / or the connection area (12) and the pipe body (11). (Item 10) In a gas piping mechanism (20) for guiding high-temperature gas of a high-temperature fuel cell, having at least one gas piping device (10) as described in any one of items 1 to 9, The gas piping mechanism (20) further includes a tubularly configured piping section (22) to guide the flow of gas in the axial direction; At least one of the gas piping devices (10) is located between two of the piping sections (22) to block conductivity along the gas piping mechanism (20), the gas piping mechanism. (Item 11) The gas piping mechanism (20) according to item 10, further comprising a compensating area (21) having a tubular sheath having a contour that is flexibly configured in the axial direction, for compensating for forces acting axially on the gas piping mechanism (20) as a result of different thermal expansions of the piping area (22) and the gas piping device (21). (Item 12) A high-temperature fuel cell system (30) having multiple fuel cell stacks (31), each having at least one gas piping mechanism (20) for guiding the anode supply gas and / or anode exhaust gas of the high-temperature gas, and at least one gas piping device (10) as described in any one of items 1 to 9, A high-temperature fuel cell system in which at least one of the gas piping mechanisms (20) has at least one of the gas piping devices (10) between at least two of the fuel cell stacks (31). (Item 13) At least one of the gas piping mechanisms (20) connects a branch to the fuel cell stack (31) for parallel supply or discharge of high-temperature gas; and, The high-temperature fuel cell system (30) according to item 12, wherein the gas piping mechanism (20) has the gas piping device (10) between each of the branch sections. (Item 14) At least two of the fuel cell stacks (31) are arranged in a vertical-downward orientation in the stack direction of the fuel cells, and A high-temperature fuel cell system (30) according to item 12 or 13, wherein at least one of the gas piping mechanisms (20) passes alongside the fuel cell stack (31) substantially parallel to the stack direction. (Item 15) Multiple of the fuel cells (31) are stacked in a tower configuration, arranged in a vertical direction in the stacking direction of the fuel cells, and each end of the fuel cell stack (31) is wired in series with respect to the others and electrically connected; and, A high-temperature fuel cell system (30) according to any one of items 12 to 14, wherein at least one of the gas piping mechanisms (20) has one of the gas piping devices (10) positioned between each branch of the gas piping mechanism (20) to one of the fuel cell stacks (31) for insulation of the gas piping mechanism (20) between the different potentials of the fuel cell stacks (31) which are wired in series along the stacking direction and stacked in phase. (Item 16) The branching section is integrated into the end plate (32) of the fuel cell stack (31) for parallel supply or discharge of high-temperature gas to or from the fuel cell stack (31); and, The end plate (32) extends through the cross-section of at least one gas piping mechanism (20) to connect the integrated branch section to the gas piping mechanism (20), in the high-temperature fuel cell system (30) according to any one of items 12 to 15. [Explanation of symbols] 【0048】 10 Gas piping system 11 Piping Body 12 Connection Areas 13 Coupling means 14 Connection surface 15 Through passage 16 Metal-coated circumferential area 20 Gas Piping Mechanism 21 Compensation area 22 Piping area 30 High-temperature fuel cell systems 31 Fuel cell stack 32 End plates for fuel cell stacks

Claims

[Claim 1] A gas piping system for conducting high-temperature gas in a high-temperature fuel cell, It comprises a piping body and a through passage extending through the piping body to guide the flow of high-temperature gas along the axial direction, A gas piping system comprising a pipe body made of a ceramic material for electrical insulation of potential at the axial end of the pipe body, and further comprising coupling means for mounting and / or sealing between the pipe body and a connection area, each coupling means being connected to the pipe body on one side via an extension intersecting the pipe body in the axial direction and to the connection area on the other side via an extension intersecting the connection area in the axial direction, wherein the coupling means and the connection area are made of the same metal material. [Claim 2] The gas piping apparatus according to claim 1, wherein the ceramic material from which the piping body is manufactured is aluminum oxide that can be coated with metal. [Claim 3] The gas piping apparatus according to claim 2, wherein the piping body has a metal coating on surface areas separated from each other in the axial direction, serving as a base for material bonding techniques. [Claim 4] The gas piping apparatus according to claim 1, further comprising a connection area located at the axial end of the piping body, having a piping connection surface that surrounds the through passage toward the axial end of the gas piping apparatus. [Claim 5] The gas piping apparatus according to claim 4, wherein the connection area is made from a metal material, preferably from an austenitic chromium-nickel steel alloy having a temperature resistance of more than 1000°C, preferably up to 1100°C, or from Ni200. [Claim 6] The gas piping apparatus according to claim 5, wherein the coupling means and the connection area are made from Ni200. [Claim 7] The aforementioned bonding means is made of a metal material, preferably 7.0 x 10 －６ The gas piping apparatus according to claim 1, manufactured from a nickel-iron-cobalt alloy having a low coefficient of thermal expansion of less than 1 / K, or from Ni200. [Claim 8] The gas piping apparatus according to claim 5, wherein the coupling means is configured in an annular shape and surrounds the circumference of the pipe body and / or one of the circumferences of the connection area for radial friction joint and / or shape joint coupling between the coupling means and the pipe body and / or between the coupling means and the connection area, respectively. [Claim 9] The gas piping apparatus according to claim 1, wherein the piping body includes a metal coating injected into the ceramic material in a circumferential area, and the coupling means and / or the connection area are joined to the metal-coated circumferential area by a brazing material for a material-bonding type of coupling between the coupling means and / or the connection area and the piping body. [Claim 10] A gas piping mechanism for guiding high-temperature gas of a high-temperature fuel cell, having at least one gas piping device according to any one of claims 1 to 9, The system further includes a tubularly configured piping section to guide the flow of gas axially along the aforementioned gas piping mechanism; A gas piping mechanism wherein at least one of the gas piping devices is positioned between two of the piping sections to block conductivity along the gas piping mechanism. [Claim 11] The gas piping mechanism according to claim 10, further comprising a compensation area having a tubular sheath having a contour that is flexibly configured in the axial direction, for compensating for forces acting in the axial direction in the gas piping mechanism as a result of different thermal expansions in the piping area and the gas piping device. [Claim 12] A high-temperature fuel cell system having a plurality of fuel cell stacks, comprising at least one gas piping mechanism for guiding the anode supply gas and / or anode exhaust gas of the high-temperature gas, and at least one gas piping device according to any one of claims 1 to 9, A high-temperature fuel cell system in which at least one of the gas piping mechanisms has at least one of the gas piping devices between at least two of the fuel cell stacks. [Claim 13] At least one of the gas piping mechanisms connects a branch to the fuel cell stack for parallel supply or discharge of high-temperature gas; and, The high-temperature fuel cell system according to claim 12, wherein the gas piping mechanism has the gas piping device between each of the branch portions. [Claim 14] At least two of the fuel cell stacks are arranged in a vertical-downward orientation in the stack direction of the fuel cell, and The high-temperature fuel cell system according to claim 12, wherein at least one of the gas piping mechanisms passes alongside the fuel cell stack substantially parallel to the stack direction. [Claim 15] Multiple fuel cells are stacked in a tower configuration, arranged in a vertical direction in the stacking direction of the fuel cells, and each end of the fuel cell stack is wired in series with respect to the others and electrically connected; and, The high-temperature fuel cell system according to claim 12, wherein at least one of the gas piping mechanisms is provided with one of the gas piping devices between each branch of the gas piping mechanism to one of the fuel cell stacks, for the purpose of insulating the gas piping mechanism between the different potentials of the fuel cell stacks which are wired in series along the stacking direction and stacked in phase. [Claim 16] The branching section is configured to be integrated into the end plate of the fuel cell stack for parallel supply or discharge of high-temperature gas to the fuel cell stack; and, The high-temperature fuel cell system according to claim 13, wherein the end plate extends through the cross-section of at least one gas piping mechanism to connect the integrated branch portion to the gas piping mechanism.

Images