Combustor unit

Abstract

To improve combustibility by uniformly dispersing gas within a combustion chamber with a simple configuration in a combustor unit for burning mixed gas of fuel gas and oxidant gas.SOLUTION: A combustor unit includes: a combustion chamber formed between an object and a partition wall; a first gas supply section; and a second gas supply section. The first gas supply section has a first space which is separated from the combustion chamber by the partition wall and is demarcated by an inner wall including the partition wall, introduces first gas which is one of fuel gas and oxidant gas into the first space, and supplies the introduced first gas from a through hole formed on the partition wall to the combustion chamber. The second gas supply section has a second space demarcated by an outer wall provided to cover the inner wall with a predetermined clearance and the inner wall, introduces second gas which is the other of the fuel gas and the oxidant gas into a second space, and supplies the introduced second gas to the combustion chamber from a side section between the object and the partition wall.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 which a fuel cell unit is housed in the lower part of the module case, a combustion chamber formed above the power generation chamber, and a reformer disposed 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 to become exhaust gas, which rises inside the module case, passes through the reformer, and is discharged outside the case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-201005 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the device described in Patent Document 1, the combustion chamber is formed as an open space above the fuel cell unit, which causes air injected into the power generation chamber and exhaust gas generated by combustion of the fuel gas in the combustion chamber to dissipate in the open space, which can cause the combustibility of the fuel gas to become unstable.

[0005] The combustor unit of the present disclosure burns a mixed gas of a fuel gas and an oxidizer gas, and has a primary object to improve combustibility by uniformly dispersing the gas within the combustion chamber with a simple configuration. [Means for solving the problem]

[0006] The combustor unit of the present disclosure takes the following measures to achieve the above-mentioned main object.

[0007] The combustor unit of the present disclosure comprises: A combustor unit that burns a mixture of a fuel gas and an oxidant gas, a combustion chamber formed between the object and the partition wall; a first gas supply unit having a first space separated from the combustion chamber by the partition wall and defined by an inner wall including the partition wall, the first gas being one of a fuel gas and an oxidizer gas, introduced into the first space and supplied to the combustion chamber through a through hole formed in the partition wall; a second gas supply unit having a second space defined by the inner wall and an outer wall provided to cover the inner wall with a predetermined gap therebetween, the second gas being the other of the fuel gas and the oxidizer gas, being introduced into the second space and supplying the introduced second gas to the combustion chamber from a side portion between the object and the partition wall; The gist of the invention is to provide the following:

[0008] In the combustor unit of the present disclosure, a first gas, which is one of the fuel gas and the oxidizer gas, is introduced into a first space defined by an inner wall including a partition wall, and is supplied to the combustion chamber through a through hole formed in the partition wall. A second gas, which is the other of the fuel gas and the oxidizer gas, is introduced into a second space defined by an outer wall and an inner wall that are provided to cover the inner wall with a predetermined gap, and is supplied to the combustion chamber from a side between the target and the partition wall through the gap between the inner wall and the outer wall. This makes it possible to uniformly distribute the fuel gas and the oxidizer gas in the combustion chamber with a simple configuration, thereby further improving combustibility. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic configuration diagram of an electrolysis system including a combustor unit according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an external perspective view of a combustor unit. [Diagram 3] FIG. 2 is an external perspective view of a combustor unit including a fuel preheater. [Figure 4] FIG. 2 is a top view of the combustor unit. [Diagram 5] 5 is a cross-sectional view of the combustor unit shown in FIG. 4 along line AA. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 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 external perspective view of the combustor unit 30 including a fuel preheater 24. In addition, Fig. 4 is a top view of the combustor unit 30, and Fig. 5 is a cross-sectional view of the combustor unit 30 of Fig. 4 taken along line AA.

[0012] As shown in FIG. 1 , the electrolysis system 10 of the 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 a combustor unit 30 of this embodiment and heat exchange units 25, 26, and 27, which are housed in a module case 28 having thermal insulation properties.

[0014] The electrolysis cell stack 21 includes a plurality of solid oxide type unit cells each including a solid electrolyte, a fuel electrode arranged on one side of the solid electrolyte, and an oxidizer electrode arranged 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 fuel electrode to generate hydrogen at the fuel electrode and oxygen at the oxidizer electrode. The power source 70 may be a system power source, a renewable energy source (e.g., a solar power generation device), a storage battery, or the like.

[0015] Since the electrolysis cell stack 21 operates in a high-temperature environment of, for example, 650-800°C, the solid electrolyte, fuel electrode, and oxidizer electrode are made of ceramic materials. In addition, to decompose water vapor into oxygen ions and hydrogen using a catalyst, the fuel electrode uses a cermet made of ceramics and a metal such as nickel that has catalytic properties. 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 into 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 via a fuel preheater 24 and a heat exchanger .

[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. Furthermore, the fuel electrode off-gas piping 23f is provided with a heat exchanger 25 and a heat exchanger 26.

[0018] One end of the 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 via a heat exchange unit 25 and a heat exchange unit 27.

[0019] One end of an oxidant electrode off-gas pipe 23 a is connected to an oxidant electrode outlet of the electrolysis cell stack 21 , and the other end of the oxidant electrode off-gas pipe 23 a is connected to a combustor unit 30 .

[0020] The fuel supply system 40 includes a water vapor supply system 41 that supplies water vapor to the fuel supply pipe 22f. Although not shown, the water vapor supply system 41 includes, for example, a water tank that stores water (raw water), a water pump that pumps the water in 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 exchanger 26, and is heated by the combustion heat from the combustor unit 30 in the fuel preheater 24, and then supplied to the anode of the electrolysis cell stack 21. In order to mix hydrogen with the water vapor, the fuel supply system 40 also includes a hydrogen supply pipe 42 connected to the fuel supply pipe 22f, a hydrogen blower 43 provided in the hydrogen supply pipe 42, and a governor 44 provided upstream of the hydrogen blower 43 in the hydrogen supply pipe 42.

[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 oxidizer electrode inlet side piping 23, and an air blower 53 installed in the air supply pipe 51. By driving the air blower 53, air sucked into the air supply pipe 51 through the filter 52 is introduced into the oxidizer supply pipe 22a, and is heated by heat exchange with the combustion exhaust gas from the combustor unit 30 in the heat exchanger 27 and is also heated by heat exchange with the anode off-gas in the heat exchanger 25, before being supplied to the oxidizer electrode of the electrolysis cell stack 21.

[0022] The hydrogen recovery system 60 recovers hydrogen from the anode off-gas discharged from the anode, and includes a hydrogen tank 61 for storing hydrogen, and a condenser 62 for condensing water vapor contained in the anode off-gas to separate gas and liquid. The condenser 62 has a heat exchange flow path capable of heat exchange with cooling water, and 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. A variable throttle valve (not shown) is also provided in the hydrogen recovery pipe 63. The anode off-gas containing hydrogen and water vapor is recovered in the hydrogen tank 61 through the hydrogen recovery pipe 63 by driving a boost pump (not shown). 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 for generating 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 42 between the hydrogen blower 43 and the governor 44, 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 hydrogen 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. The combustion hydrogen supply pipe 65 is provided with a flow meter, not shown.

[0024] As shown in Figures 2 to 5, the combustor unit 30 of this embodiment includes a case 31, an inner housing 32, and a partition plate 33 which define a combustion chamber C1, a first dispersion chamber C2, and a second dispersion chamber C3, a fuel introduction pipe 34 which introduces fuel (hydrogen for combustion) into the first dispersion chamber C2, an air introduction pipe 35 which introduces air (oxidizer electrode off-gas) into the second dispersion chamber C3, and an igniter (not shown) which ignites the mixed gas of fuel and air introduced into the combustion chamber C1 via the first dispersion chamber C2 and the second dispersion chamber C3.

[0025] The case 31 is a rectangular, box-shaped member having a bottom wall 31b and a side wall 31s and opening at the top. As shown in FIG. 3, the fuel preheater 24, which is rectangular and flat, is joined to the top of the case 31 by adhesion with a heat-resistant adhesive or bolt fastening via a gasket so as to close the upper opening. The inner housing 32 has a bottom wall 32b and a side wall 31s, and is disposed in 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. A plurality of spacers SP are provided between the bottom wall 31b of the case 31 and the bottom wall 32b of the inner housing 32 to form a uniform gap. The upper edge 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. The partition plate 33 is a rectangular flat plate. Both ends of the partition plate 33 in the short direction are joined by welding or the like to both side walls 32s in the short direction of the inner housing 32. As a result, as shown in Fig. 5, the fuel preheater 24, the partition plate 33, a part of the side wall 31s of the case 31, and a part of the side wall 32s of the inner housing 32 define a combustion chamber C1, the partition plate 33 and a part of the bottom wall 32b and side wall 32s of the inner housing 32 define a first dispersion chamber C2, and the bottom wall 31b and a part of the side wall 31s of the case 31 and the bottom wall 32b and side wall 32s of the inner housing 32 define a second dispersion chamber C3. The combustion chamber C1 and the first dispersion chamber C2 are connected via a plurality (a large number) of through holes 33o (see Figures 2, 4 and 5) formed in the partition plate 33, and the combustion chamber C1 and the second dispersion chamber C3 are connected via a plurality (a large number) of through holes 32o (see Figures 2 and 4) formed in the portion of the side wall 32s of the inner housing 32 facing the combustion chamber C1 (the portion above the partition plate 33).

[0026] The fuel introduction pipe 34 is disposed so as to penetrate one side wall 31s in the longitudinal direction of the case 31 and extend to the center in the longitudinal direction in the first dispersion chamber C2. The inlet of the fuel introduction pipe 34 is connected to the combustion hydrogen supply pipe 65. The outlet of the fuel introduction pipe 34 is connected to the outlet of the outlet pipe 34o, and the outlet pipe 34o is disposed so that the open end of the outlet pipe 34o is slightly separated from the bottom wall 31b of the case 31 and the fuel (combustion hydrogen) is discharged toward the bottom wall 31b of the case 31. The fuel (combustion hydrogen) discharged from the outlet pipe 34o of the fuel introduction pipe 34 collides with the bottom wall 32b of the inner housing 32 and diffuses to the surroundings, and is supplied to the combustion chamber C1 through a plurality of through holes 33o formed in the partition plate 33. This allows the fuel (combustion hydrogen) supplied to the combustion chamber C1 through the first dispersion chamber C2 to spread throughout the entire combustion chamber C1.

[0027] The air introduction pipe 35 is disposed so as to penetrate one side wall 31s in the longitudinal direction of the case 31 and extend in parallel with the fuel introduction pipe 34 to the center in the longitudinal direction in the first dispersion chamber C2. The oxidizer electrode off-gas pipe 23a is connected to the inlet of the air introduction pipe 35. The outlet pipe 35o is connected to the outlet of the air introduction pipe 35, and the open end of the outlet pipe 35o is connected to the through hole 32h formed in the bottom wall 31b of the case 31. The air (oxidizer electrode off-gas) discharged from the outlet pipe 35o of the air introduction pipe 35 collides with the bottom wall 31b of the case 31 and diffuses to the surroundings, passes through the gap between the case 31 and the inner housing 32, and is supplied to the combustion chamber C1 through a plurality of through holes 32o formed in the side wall 32s of the inner housing 32, which is the side between the fuel preheater 24 and the partition plate 33. By narrowing the gap (second dispersion chamber C3) between the case 31 and the inner housing 32, it is possible to suppress the uneven flow of air (oxidizer electrode off-gas) due to pressure loss, and to allow the air (oxidizer electrode off-gas) supplied to the combustion chamber C1 via the second dispersion chamber C3 to spread throughout the entire combustion chamber C1.

[0028] As a result, in the combustor unit 30 of the present embodiment, the fuel (hydrogen for combustion) and air (oxidizer electrode off-gas) can be uniformly dispersed within the combustion chamber C1, thereby making it possible to further improve combustibility.

[0029] In this embodiment, the combustor unit 30 is disposed above the electrolysis cell stack 21, and the fuel preheater 24 is disposed directly above the combustion chamber C1 of the combustor unit 30. As shown in FIG. 3, the fuel preheater 24 has a fuel flow path including a straight portion 24s and a turn-back portion 24t, and allows the fuel (steam) supplied from the fuel supply system 40 to flow in a meandering manner. This allows the fuel (steam) flowing through the fuel flow path of the fuel preheater 24 to be directly heated by the combustion heat generated by the fuel of the mixed gas of the fuel (hydrogen for combustion) and the air (oxidizer electrode off-gas) in the combustion chamber C1, and the combustion heat can be transferred to the electrolysis stack 21. As a result, the fuel (steam) and the electrolysis cell stack 21 can be heated to the required temperature with less energy (hydrogen for combustion), and the efficiency of the electrolysis system 10 can be further improved.

[0030] In the above-described embodiment, fuel (hydrogen for combustion) is introduced into the first dispersion chamber C2 and air (oxidizer electrode off-gas) is introduced into the second dispersion chamber C3, but air (oxidizer electrode off-gas) may be introduced into the first dispersion chamber C2 and fuel (hydrogen for combustion) may be introduced into the second dispersion chamber C3.

[0031] In the above-described embodiment, the combustor unit 30 heats the fuel preheater 24 as the heating target, but an air preheater that preheats the air supplied from the air supply system 50 may be provided, and the air preheater may be the heating target.

[0032] In the above-described embodiment, the electrolysis system 10 performs an electrolysis operation to generate hydrogen by high-temperature steam electrolysis. However, the electrolysis system 10 may use the electrolysis cell stack 21 as a reversible operation solid oxide cell stack, and switch between the electrolysis operation and a power generation operation that generates power by a reaction between hydrogen as a fuel gas and oxygen contained in the air.

[0033] 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.

[0034] The above describes the form 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 without departing from the gist of the present disclosure. [Industrial Applicability]

[0035] The present disclosure is applicable to the combustion unit manufacturing industry and the like. [Explanation of symbols]

[0036] 21 electrolysis cell stack (solid oxide cell stack), 30 combustor unit, 31 case (outer wall), 32 inner housing (inner wall), 33 partition plate (partition wall), 34 fuel introduction pipe (first gas flow path), 35 air introduction pipe (second gas flow path), C1 combustion chamber, C2 first dispersion chamber (first space), C3 second dispersion chamber (second space).

Claims

1. A combustor unit that burns a mixture of a fuel gas and an oxidant gas, a combustion chamber formed between the object and the partition wall; a first gas supply unit having a first space separated from the combustion chamber by the partition wall and defined by an inner wall including the partition wall, the first gas being one of a fuel gas and an oxidizer gas, being introduced into the first space and the introduced first gas being supplied to the combustion chamber through a through hole formed in the partition wall; a second gas supply unit having a second space defined by the inner wall and an outer wall provided to cover the inner wall with a predetermined gap therebetween, the second gas being the other of the fuel gas and the oxidizer gas, and supplying the introduced second gas to the combustion chamber from a side portion between the object and the partition wall; A combustor unit comprising:

2. 2. The combustor unit of claim 1, the first gas supply unit has a first gas flow path extending into the first space and discharging the first gas toward a wall surface of the inner wall opposite to the partition wall; Combustor unit.

3. 3. A combustor unit according to claim 1 or 2, the second gas supply unit extends into the first space, is connected to a through hole formed in a wall surface of the inner wall opposite to the partition wall, and has a second gas flow path that introduces the second gas into the second space through the through hole. Combustor unit.

4. 3. A combustor unit according to claim 1 or 2, a combustion chamber provided on an upper portion of the solid oxide cell stack for combusting a mixture of fuel off-gas and oxidant off-gas from the solid oxide cell stack; Combustor unit.

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