Combustor unit

Abstract

To preheat supply gas by efficiently transmitting heat generated in a combustion part to a supply gas flow passage.SOLUTION: The combustor unit is disposed together with the cell stack, and includes a combustion portion, a filling portion, a combustion fuel gas supply portion that supplies a combustion fuel gas to the filling portion, a combustion-supporting gas supply portion that supplies a combustion-supporting gas to the combustion portion, a partition member that is formed of a heat-transferable member and partitions between the combustion portion and the filling portion, a supply gas flow path that is formed inside the partition member and through which a supply gas supplied to the cell stack flows, and a communication hole that is formed at a position avoiding the supply gas flow path of the partition member and through which the combustion portion and the filling portion communicate with each other.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present specification discloses a combustor unit. [Background technology]

[0002] A solid oxide fuel cell device has been proposed that includes a module case built into a housing via a heat insulating material, a power generation chamber in the lower part of the module case that houses fuel cell units, a combustion chamber formed above the power generation chamber, and a reformer arranged above the combustion chamber (see, for example, Patent Document 1). Fuel gas that is not used for power generation in the power generation chamber is combusted in the fuel chamber, and exhaust gas generated by the combustion of the fuel gas rises inside the module case, passes through the reformer while heating it, and is discharged outside the case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-201005 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described device, the combustion chamber is formed as an open space above the fuel cell unit, and therefore the air injected into the power generation chamber and the exhaust gas generated by the combustion of the fuel gas in the combustion chamber dissipate in the open space, making the combustibility of the fuel gas unstable and sometimes preventing the heating object from being heated sufficiently.

[0005] A primary object of the present disclosure is to efficiently preheat the supply gas supplied to the cell stack using heat generated in the combustion section. [Means for solving the problem]

[0006] The present disclosure has adopted the following means to achieve the above-mentioned main object.

[0007] The combustor unit of the present disclosure is a combustor unit arranged together with a cell stack, and comprises: a combustion section that receives a supply of combustion fuel gas and a combustion supporting gas and burns the supplied gas; a filling section that is filled with the combustion fuel gas; a combustion fuel gas supply section that supplies the combustion fuel gas to the filling section; a combustion supporting gas supply section that supplies the combustion supporting gas to the combustion section; and a partition member that separates the combustion section from the filling section, wherein the partition member is formed from a heat-transferring material, a supply gas flow path is formed inside the partition member through which the supply gas supplied to the cell stack flows, and a communication hole is formed in the partition member at a position away from the supply gas flow path, connecting the combustion section to the filling section.

[0008] In the combustor unit disclosed herein, the combustion fuel gas flowing into the plenum section is supplied from the plenum section through the communication holes to the combustion section, where it is combusted together with the supporting gas supplied to the combustion section. The heat generated by the combustion of the combustion fuel gas is transferred to the partition member that defines the combustion section and preheats the supply gas flowing through the supply gas flow path formed inside the partition member. This allows the heat generated in the combustion section to be used to efficiently preheat the supply gas supplied to the cell stack. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of an electrolysis system including a combustor unit according to an embodiment of the present invention. FIG. [Figure 2] FIG. 2 is an external perspective view of the combustor unit. [Figure 3] FIG. 2 is an exploded perspective view of the combustor unit. [Figure 4] FIG. 2 is a plan view of the combustor unit. [Figure 5] 5 is a cross-sectional view taken along the line AA in FIG. 4. [Figure 6] FIG. 4 is a cross-sectional view of a combustor unit according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present disclosure will be described with reference to the drawings.

[0011] Fig. 1 is a schematic configuration diagram of an electrolysis system 10 including a combustor unit 30 of this embodiment, Fig. 2 is an external perspective view of the combustor unit 30, and Fig. 3 is an exploded perspective view of the combustor unit 30. Furthermore, Fig. 4 is a plan view of the combustor unit 30, and Fig. 5 is a cross-sectional view taken along line AA in Fig. 4.

[0012] As shown in FIG. 1 , the electrolysis system 10 of this embodiment includes an electrolysis module 20 including an electrolysis cell stack 21, a fuel supply system 40 that supplies water vapor as a fuel gas to the electrolysis module 20, an air supply system 50 that supplies air as a sweep gas to the electrolysis module 20, a hydrogen recovery system 60 that recovers hydrogen produced by the electrolysis operation, and a power supply 70 that supplies power required for electrolysis to the electrolysis cell stack 21.

[0013] In addition to the electrolysis cell stack 21, the electrolysis module 20 includes the combustor unit 30 of this embodiment and heat exchange sections 25, 26, and 27, all of which are housed in a module case 28 having thermal insulation properties.

[0014] The electrolysis cell stack 21 includes a plurality of solid oxide unit cells, each of which includes a solid electrolyte, an anode disposed on one side of the solid electrolyte, and an oxidizer electrode disposed on the other side of the solid electrolyte. The electrolysis cell stack 21 receives power from a power source 70 and electrolyzes water vapor supplied to the anode, thereby producing hydrogen at the anode and oxygen at the oxidizer electrode. The power source 70 may be a system power supply, a renewable energy device (e.g., a solar power generation device), a storage battery, or the like.

[0015] The electrolysis cell stack 21 operates in a high-temperature environment of, for example, 650-800°C, so the solid electrolyte, fuel electrode, and oxidizer electrode are made of ceramic materials. Furthermore, to decompose water vapor into oxygen ions and hydrogen using a catalyst, the fuel electrode is made of a cermet made of ceramic and a catalytic metal such as nickel. To maintain good catalytic activity of the fuel electrode, it is necessary to keep the fuel electrode in a reducing atmosphere and prevent oxidation of the metal. For this reason, in this embodiment, hydrogen is mixed with the water vapor supplied to the fuel electrode to prevent oxidation.

[0016] One end of a fuel supply pipe 22f is connected to the fuel electrode inlet of the electrolysis cell stack 21, and the other end of the fuel supply pipe 22f is connected to a fuel supply system 40. A fuel preheating unit 24 and a heat exchange unit 26 are provided in the fuel supply pipe 22f.

[0017] One end of a fuel electrode off-gas piping 23f is connected to the fuel electrode outlet of the electrolysis cell stack 21, and the other end of the fuel electrode off-gas piping 23f is connected to a hydrogen recovery system 60. A heat exchanger 25 and a heat exchanger 26 are provided in the fuel electrode off-gas piping 23f.

[0018] One end of an oxidant supply pipe 22a is connected to the oxidant electrode inlet of the electrolysis cell stack 21, and the other end of the oxidant supply pipe 22a is connected to an air supply system 50. A heat exchanger 25 and a heat exchanger 27 are provided in the oxidant supply pipe 22a.

[0019] One end of an oxidant electrode off-gas pipe 23a is connected to an oxidant electrode outlet of the electrolysis cell stack 21, and the other end of the oxidant electrode off-gas pipe 23a is connected to the combustor unit 30. The oxidant electrode off-gas containing oxygen discharged from the oxidant electrode outlet is supplied to the combustor unit 30 as a combustion supporting gas.

[0020] The fuel supply system 40 includes a water vapor supply unit 41 that supplies water vapor to the fuel supply pipe 22f. Although not shown, the water vapor supply unit 41 includes, for example, a water tank that stores water (raw material water), a water pump that pumps the water from the water tank, and an evaporator that evaporates the water from the water pump. The fuel (water vapor) supplied from the fuel supply system 40 is heated by heat exchange with the anode off-gas in the heat exchange unit 26 and is also heated by combustion heat from the combustor unit 30 in the fuel preheating unit 24 before being supplied to the anode of the electrolysis cell stack 21. The fuel supply system 40 also includes a hydrogen supply unit 42 that mixes hydrogen with the water vapor. The hydrogen supply unit 42 also includes a hydrogen supply pipe 43 connected to the fuel supply pipe 22f, a hydrogen blower 44 provided in the hydrogen supply pipe 43, and a governor 45 provided in the hydrogen supply pipe 43 upstream of the hydrogen blower 44.

[0021] The air supply system 50 includes an air supply pipe 51 having one end connected to a filter 52 and the other end connected to the oxidant supply pipe 22a, and an air blower 53 installed in the air supply pipe 51. By driving the air blower 53, air is drawn into the air supply pipe 51 through the filter 52, introduced into the oxidant supply pipe 22a, and heated in the heat exchanger 27 by heat exchange with the combustion exhaust gas discharged from the combustor unit 30, and also heated in the heat exchanger 25 by heat exchange with the anode off-gas, before being supplied to the oxidant electrode of the electrolysis cell stack 21.

[0022] The hydrogen recovery system 60 recovers hydrogen from anode off-gas containing hydrogen and water vapor discharged from the anode outlet. It includes a hydrogen tank 61 for storing hydrogen and a condenser 62 for condensing the water vapor contained in the anode off-gas to separate the gas and liquid. The condenser 62 has a heat exchange flow path capable of heat exchange with cooling water. The other end of the anode off-gas pipe 23f is connected to the inlet of the heat exchange flow path, and one end of the hydrogen recovery pipe 63 is connected to the outlet of the heat exchange flow path. The hydrogen tank 61 is connected to the other end of the hydrogen recovery pipe 63. The hydrogen recovery pipe 63 is also provided with a variable throttle valve and a boost pump (not shown). The anode off-gas containing hydrogen and water vapor exchanges heat with the cooling water to condense the water vapor contained in the anode off-gas. The boost pump then drives the hydrogen recovery pipe 63 to recover the water condensed from the anode off-gas into the hydrogen tank 61. The condensed water obtained by condensing the anode off-gas in the condenser 62 is stored in a water tank (not shown). The water stored in the water tank is used as raw water to generate steam for electrolysis.

[0023] The hydrogen recovery system 60 also includes a recycle pipe 64 that branches off from the hydrogen recovery pipe 63 and is connected to the hydrogen supply pipe 43 between the hydrogen blower 44 and the governor 45, and recycles a portion of the recovered hydrogen as hydrogen for preventing oxidation. The recycle pipe 64 is provided with a flow meter and a variable throttle valve, not shown. The hydrogen recovery system 60 also includes a combustion fuel gas supply pipe 65 that branches off from the hydrogen recovery pipe 63 and is connected to the combustor unit 30, and supplies a portion of the recovered hydrogen to the combustor unit 30 as combustion fuel gas (combustion hydrogen). The combustion fuel gas supply pipe 65 is provided with a flow meter, not shown.

[0024] 2 to 5, the combustor unit 30 of this embodiment includes a case 31 and an inner housing 32 that define a combustion chamber C1, a combustion fuel gas chamber C2, and a supporting gas chamber C3, and a partition plate 33 that is installed in the inner housing 32 to separate the combustion chamber C1 from the combustion fuel gas chamber C2. The combustor unit 30 also includes a combustion fuel gas introduction pipe 34 that introduces combustion fuel gas (combustion hydrogen) into the combustion fuel gas chamber C2, a supporting gas introduction pipe 35 that introduces supporting gas (oxidizer electrode off-gas) into the supporting gas chamber C3, and an igniter (not shown) that ignites a mixed gas of the combustion fuel gas and the supporting gas that is introduced into the combustion chamber C1 via the combustion fuel gas chamber C2 and the supporting gas chamber C3, respectively. In this embodiment, the combustor unit 30 is installed above the electrolytic cell stack 21 so that the combustion chamber C1 and the electrolytic cell stack 21 are close to each other in the vertical direction, and the combustion chamber C1 is formed below the combustion fuel gas chamber C2.

[0025] As shown in FIG. 2(a), the case 31 is a rectangular, box-shaped member having a bottom wall (not shown), side walls 31s, and a top wall 31t. As shown in FIGS. 4 and 5, the inner housing 32 has a top wall 32t and a side wall 31s, and is disposed within the case 31 so that the case 31 and the inner housing 32 form a hollow double wall on both sides of the short side of the case 31. The lower end portion of the side wall 32s of the inner housing 32 is bent and joined to the side wall 31s of the case 31 by welding or the like. Note that a plurality of spacers (not shown) are provided between the top wall 31t of the case 31 and the top wall 32t of the inner housing 32 to form a uniform gap.

[0026] The partition plate 33 is formed in a rectangular plate shape. As shown in Figures 4 and 5, both ends of the partition plate 33 in the short direction are joined to both side walls 32s of the inner housing 32 in the short direction by welding or the like. As a result, a combustion chamber C1 is defined by the partition plate 33, the bottom wall (not shown) of the case 31, parts of the side walls 31s of the case 31, and parts of the side walls 32s of the inner housing 32, a combustion fuel gas chamber C2 is defined by the partition plate 33 and parts of the top wall 32t and side walls 32s of the inner housing 32, and a combustion supporting gas chamber C3 is defined by parts of the top wall 31t and side walls 31s of the case 31 and the top wall 32t and side walls 32s of the inner housing 32. The combustion chamber C1 and the combustion fuel gas chamber C2 are connected via a plurality (a large number) of communication holes 33o (see Figures 2(b), 4 and 5) formed in the partition plate 33, and the combustion chamber C1 and the supporting gas chamber C3 are connected via a plurality (a large number) of communication holes 32o (see Figures 2(b) and 4) formed in the portion of the side wall 32s of the inner housing 32 facing the combustion chamber C1 (the portion below the partition plate 33).

[0027] As shown in FIG. 3, the combustion fuel gas introduction pipe 34 is disposed so as to penetrate one side wall 31s in the longitudinal direction (left-right direction in the figure) of the case 31 and extend to the center of the combustion fuel gas chamber C2 in the longitudinal direction. A combustion fuel gas supply pipe 65 is connected to the inlet of the combustion fuel gas introduction pipe 34. As shown in FIG. 5, an outlet pipe 34o is connected to the outlet of the combustion fuel gas introduction pipe 34, and the outlet pipe 34o is disposed so that its open end is slightly spaced from the top wall 32t of the inner housing 32 and the combustion fuel gas (combustion hydrogen) is discharged toward the top wall 32t of the inner housing 32. The combustion fuel gas (combustion hydrogen) discharged from the outlet pipe 34o of the combustion fuel gas introduction pipe 34 collides with the top wall 32t of the inner housing 32 and diffuses to the surroundings, and is discharged downward through a plurality of communication holes 33o formed in the partition plate 33 to be supplied to the combustion chamber C1. This allows the combustion fuel gas (combustion hydrogen) supplied to the combustion chamber C1 via the combustion fuel gas chamber C2 to be distributed throughout the entire combustion chamber C1.

[0028] As shown in Fig. 3, the combustion supporting gas introduction pipe 35 is disposed so as to penetrate one side wall 31s in the longitudinal direction of the case 31 and extend parallel to the combustion fuel gas introduction pipe 34 within the combustion fuel gas chamber C2 to the center in the longitudinal direction. The oxidizer electrode off-gas pipe 23a is connected to the inlet of the combustion supporting gas introduction pipe 35. As shown in Fig. 5, the outlet pipe 35o is connected to the outlet of the combustion supporting gas introduction pipe 35, and the open end of the outlet pipe 35o is joined by welding or the like to a through-hole 32h formed in the top wall 32t of the inner housing 32. The combustion supporting gas (oxidizer electrode off-gas) discharged from the outlet pipe 35o of the combustion supporting gas introduction pipe 35 collides with the top wall 31t of the case 31 and diffuses to the surroundings, passes through the combustion supporting gas chamber C3 defined in the gap between the case 31 and the inner housing 32, and is then discharged from the opposing side walls of the inner housing 32. The combustion supporting gas (oxidizer electrode off-gas) supplied to the combustion chamber C1 via the combustion supporting gas chamber C3 can be distributed throughout the entire combustion chamber C1.

[0029] In this way, in the combustor unit 30 of this embodiment, the combustion fuel gas (combustion hydrogen) and the combustion supporting gas (oxidizer electrode off-gas) can be uniformly dispersed within the combustion chamber C1, thereby further improving combustibility.

[0030] The fuel preheating section 24 is formed inside the partition plate 33. As shown in FIG. 4, the fuel preheating section 24 includes straight sections 24s and turning sections 24t, and has a fuel flow path through which the fuel (steam) supplied from the fuel supply system 40 flows in a serpentine manner. As shown in FIG. 4, a plurality of communication holes 33o that communicate between the combustion chamber C1 and the combustion fuel gas chamber C2 are formed in the boundary portions between adjacent straight sections 24s so as to be aligned along the extension direction of the straight sections 24s. This allows a plurality (a large number) of communication holes 33o to be formed in the partition plate 33 without obstructing the fuel flow path.

[0031] As described above, the combustion chamber C1 is formed below the combustion fuel gas chamber C2 so as to be vertically adjacent to the electrolysis cell stack 21, and the partition plate 33 is formed of a metal plate member arranged to separate the combustion chamber C1 and the combustion fuel gas chamber C2. Therefore, the combustion heat generated by the combustion of the mixed gas of the combustion fuel gas (combustion hydrogen) and the combustion supporting gas (oxidizer electrode off-gas) in the combustion chamber C1 can be efficiently transferred to the fuel preheating unit 24, and the fuel (steam) flowing through the fuel flow path of the fuel preheating unit 24 can be directly heated, and the combustion heat can be transferred to the electrolysis cell stack 21. As a result, the fuel (steam) and the electrolysis cell stack 21 can be heated to the required temperature using less energy (combustion hydrogen), thereby further improving the efficiency of the electrolysis system 10.

[0032] FIG. 6 is a cross-sectional view of a combustor unit 130 according to another embodiment. The combustor unit 130 according to the another embodiment includes a fuel preheating section 24 in which a thermal storage material 100 is disposed within a fuel flow path. The thermal storage material 100 has a core containing a metal alloy and a ceramic shell made of alumina (Al2O3) or the like that covers the core. The thermal storage material 100 is configured as a phase change material (PCM) that stores latent heat when the core melts at approximately 600°C. In this embodiment, the thermal storage material 100 has a particle diameter of approximately several mm, and the particles of the thermal storage material 100 are filled in the fuel flow path of the fuel preheating section 24 along approximately the entire length of the flow path. This improves the efficiency of combustion heat transfer within the combustor unit 130, uniforms the temperature of the fuel preheating section 24 (fuel flow path), and efficiently heats the fuel passing through the fuel preheating section 24. Furthermore, when the electrolysis system 10 is operated intermittently, by storing the heat generated during electrolysis in the heat storage material 100, the heat stored in the heat storage material 100 can be used as auxiliary heat for increasing the temperature of the electrolysis module 20 (electrolysis cell stack 21) the next time the electrolysis system 10 is started after operation has stopped, thereby further improving efficiency.

[0033] In the above-described embodiment, the combustor unit 30 heated the fuel preheating section 24 as the heating target, but an air preheating section that preheats the air supplied from the air supply system 50 may be provided, and the air preheating section may be the heating target.

[0034] In the above-described embodiment, the electrolysis system 10 performs electrolysis operation to produce hydrogen by high-temperature steam electrolysis. However, the electrolysis system 10 may also use the electrolysis cell stack 21 as a reversible solid oxide cell stack, and switch between electrolysis operation and power generation operation to generate power by reacting hydrogen as fuel gas with oxygen contained in the air.

[0035] In the above-described embodiment, the combustor unit 30 is applied to the electrolysis system 10, but it may also be applied to a fuel cell system including a fuel cell stack.

[0036] The above describes the forms for implementing the present disclosure using embodiments, but the present disclosure is not limited to these embodiments in any way, and it goes without saying that the present disclosure can be implemented in various forms within the scope that does not deviate from the gist of the present disclosure. [Industrial Applicability]

[0037] The present disclosure is applicable to the combustion unit manufacturing industry and the like. [Explanation of symbols]

[0038] 1 electrolysis cell stack (cell stack), 24 fuel preheating section (supply gas flow path), 24s Straight section, 24t folded section, 30 combustor unit, 33 partition plate (partition member), 33o communication hole, 34 combustion fuel gas introduction pipe (combustion fuel gas supply section), 35 Auxiliary combustion gas inlet pipe (auxiliary combustion gas supply section), C1 combustion chamber (combustion section), C2 combustion fuel gas chamber (filling section).

Claims

1. A combustor unit disposed with the cell stack, a combustion section that receives a supply of combustion fuel gas and a combustion supporting gas and burns the gas; a filling section filled with the combustion fuel gas; a combustion fuel gas supply unit that supplies the combustion fuel gas to the filling unit; a combustion supporting gas supply unit that supplies the combustion supporting gas to the combustion unit; a partition member separating the combustion section and the plenum section; Equipped with the partition member is formed of a heat-transmitting material, a supply gas flow path through which a supply gas supplied to the cell stack flows is formed inside the partition member; a communication hole that communicates the combustion section with the plenum section is formed in the partition member at a position that avoids the supply gas flow path; Combustor unit.

2. 10. The combustor unit of claim 1, the combustion section and the plenum section are arranged above the cell stack so as to be aligned vertically, The combustion section is disposed below the plenum section, the communication hole penetrates the partition member vertically so that the combustion fuel gas is supplied to the combustion section from above; Combustor unit.

3. 3. The combustor unit of claim 2, The combustion supporting gas supply unit supplies the combustion supporting gas to the combustion unit from a side. Combustor unit.

4. 4. A combustor unit according to claim 1, further comprising: the supply gas flow path is formed in a serpentine shape by a plurality of straight portions extending parallel to one another and turn-back portions connecting ends of adjacent straight portions, a plurality of the communication holes are formed between the adjacent linear portions so as to be aligned along the extending direction of the linear portions; Combustor unit.

5. 4. A combustor unit according to claim 1, further comprising: The supply gas flow path has a heat storage material therein. Combustor unit.

6. 6. The combustor unit of claim 5, The heat storage material is configured by covering a core containing an alloy as a latent heat storage material with a ceramic shell. Combustor unit.

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