Injection nozzle

Abstract

To provide a spray nozzle which can easily burn ligneous gas in a spray nozzle used in a gas combustor for burning ligneous gas produced from wood chips.SOLUTION: In a spray nozzle 23, a cap member 28 comprises a first cylindrical part 28a arranged on the outer peripheral side of the small diameter cylindrical part 27b of a nozzle body 27, where a toric channel 28d into which compressed air having flowed out of the other end opening of the cannel 27h of the nozzle body 27 and an auxiliary gas flow, and a plurality of channels 28e leading from the channel 28d to the inner peripheral face of the first cylindrical part 28d are formed in the cap member 28. The channel 28d are formed so as to recess from a step face 28c formed at a boundary part between the first cylindrical part 28a and the second cylindrical part 28b on the inner peripheral side of the cap member 28 toward the first cylindrical part 28a side, and one end of the channel 28e is joined with the channel 28d, and the other end of the channel 28e is opened in the inner peripheral face of the first cylindrical part 28a.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an injection nozzle for use in a gas burner for burning wood gas produced from wood chips. 。 [Background technology]

[0002] Conventionally, there is known a fluid nozzle that mixes a plurality of fluids and sprays the mixed fluid on a target object (see, for example, Patent Document 1). The fluid nozzle described in Patent Document 1 includes a main body having a nozzle part with a flow path formed in the center through which a first fluid flows and an open tip, and a cylindrical cap that covers the nozzle part. A swirl groove is formed on the inner periphery of the cap to allow the second fluid to pass therethrough. The cap also has a through hole formed therein to allow the second fluid to pass therethrough after passing through the swirl groove. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-78771 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present inventors have been studying the structure of an injection nozzle (fluid nozzle) used in a gas combustor for burning wood gas generated from wood chips. This injection nozzle injects wood gas. Generally, wood gas contains a relatively large amount of moisture, so wood gas is difficult to burn. In other words, it is not easy to burn wood gas in a gas combustor.

[0005] Therefore, an object of the present invention is to provide an injection nozzle for use in a gas burner for burning wood gas produced from wood chips, which makes it possible to easily burn wood gas. 。 [Means for solving the problem]

[0006] In order to solve the above problems, the injection nozzle of the present invention is an injection nozzle used in a gas burner for burning wood gas generated from wood chips, and includes a cylindrical nozzle body having a main body-side first flow passage formed at its center through which wood gas flows, and a cylindrical cap member fixed to the tip side of the nozzle body, the nozzle body includes a cylindrical small diameter tube portion constituting the tip of the nozzle body, and a cylindrical large diameter tube portion connected to the small diameter tube portion and having an outer diameter larger than that of the small diameter tube portion, and the nozzle body includes a main body-side first flow passage through which compressed air flows. a second flow passage through which auxiliary fuel gas flows, and a third flow passage on a main body side through which auxiliary fuel gas flows, one end of the second flow passage on the main body side and one end of the third flow passage on the main body side open at an outer circumferential surface of the large diameter cylindrical portion, and the other end of the second flow passage on the main body side and the other end of the third flow passage on the main body side open at a step surface formed at a boundary portion between the small diameter cylindrical portion and the large diameter cylindrical portion on the outer circumferential side of the nozzle main body, and the cap member includes a first cylindrical portion disposed on the outer circumferential side of the small diameter cylindrical portion, and a second cylindrical portion connected to the first cylindrical portion and fixed to the large diameter cylindrical portion, and the inner diameter of the first cylindrical portion is smaller than the inner diameter of the second cylindrical portion. The cap member is formed with an annular cap-side first flow passage into which the compressed air and auxiliary fuel gas flowing out from the opening at the other end of the main body-side second flow passage and the opening at the other end of the main body-side third flow passage flow in, and a plurality of cap-side second flow passages leading from the cap-side first flow passage to the inner circumferential surface of the first cylindrical portion, and the cap-side first flow passages are formed so as to be recessed from a step surface formed at a boundary portion between the first cylindrical portion and the second cylindrical portion on the inner circumferential side of the cap member toward the first cylindrical portion, and the cap member is formed in a cylindrical shape when viewed in the axial direction. The shape of the cap-side first flow path is annular, one end of the cap-side second flow path is connected to the cap-side first flow path and the other end of the cap-side second flow path opens at the inner circumferential surface of the first cylindrical portion, and one end of the cap-side second flow path and the other end of the cap-side second flow path are offset circumferentially from the first cylindrical portion.The small diameter cylindrical portion is characterized in that wood gas is injected from the opening at the tip of the small diameter cylindrical portion, and a mixed gas of compressed air and auxiliary fuel gas is injected from between the outer circumferential surface of the small diameter cylindrical portion and the inner circumferential surface of the first cylindrical portion at the tip side of the small diameter cylindrical portion and the first cylindrical portion.

[0007] In the injection nozzle of the present invention, the cap member includes a first cylindrical portion disposed on the outer circumferential side of the small diameter cylindrical portion of the nozzle body, and the cap member is formed with an annular cap-side first flow passage into which compressed air and auxiliary fuel gas flowing out from an opening at the other end of the body-side second flow passage and an opening at the other end of the body-side third flow passage formed in the nozzle body flow in, and a plurality of cap-side second flow passages leading from the cap-side first flow passage to the inner circumferential surface of the first cylindrical portion. Also, in the present invention, the cap-side first flow passage is formed so as to be recessed toward the first cylindrical portion from a step surface formed at the boundary between the first cylindrical portion and the second cylindrical portion on the inner circumferential side of the cap member, and one end of the cap-side second flow passage is connected to the cap-side first flow passage, and the other end of the cap-side second flow passage opens at the inner circumferential surface of the first cylindrical portion.

[0008] Therefore, in the present invention, the compressed air and auxiliary fuel gas that have passed through the cap-side second flow passage flow out toward the inner circumferential side of the first cylindrical portion. Therefore, in the present invention, the compressed air and auxiliary fuel gas that have passed through the cap-side second flow passage collide with the outer circumferential surface of the small-diameter cylindrical portion of the nozzle body, and a turbulent flow can be efficiently generated between the outer circumferential surface of the small-diameter cylindrical portion and the inner circumferential surface of the first cylindrical portion. As a result, in the present invention, it is possible to efficiently mix the wood gas injected from the opening at the tip of the small-diameter cylindrical portion and the mixed gas injected from between the outer circumferential surface of the small-diameter cylindrical portion and the inner circumferential surface of the first cylindrical portion at the tip side of the small-diameter cylindrical portion and the first cylindrical portion. Therefore, according to the study by the present inventor, in a gas burner using the injection nozzle of the present invention, it is possible to easily burn wood gas.

[0009] In the present invention, the other end of the main body-side second flow passage and the other end of the main body-side third flow passage also directly communicate with the outer peripheral surface of the small diameter cylindrical portion and the inner peripheral surface of the first cylindrical portion, and the compressed air and auxiliary fuel gas flowing out from the opening at the other end of the main body-side second flow passage and the opening at the other end of the main body-side third flow passage also preferably directly flow into between the outer peripheral surface of the small diameter cylindrical portion and the inner peripheral surface of the first cylindrical portion. With this configuration, it is possible to generate a more complex turbulent flow between the outer peripheral surface of the small diameter cylindrical portion and the inner peripheral surface of the first cylindrical portion by the compressed air and auxiliary fuel gas flowing into between the outer peripheral surface of the small diameter cylindrical portion and the inner peripheral surface of the first cylindrical portion toward the inner peripheral side of the first cylindrical portion, and the compressed air and auxiliary fuel gas flowing directly into between the outer peripheral surface of the small diameter cylindrical portion and the inner peripheral surface of the first cylindrical portion toward the tip side of the small diameter cylindrical portion and the first cylindrical portion. Therefore, it is possible to more efficiently mix the wood gas sprayed from the opening at the tip of the small diameter cylindrical portion and the mixed gas sprayed from between the outer peripheral surface of the small diameter cylindrical portion and the inner peripheral surface of the first cylindrical portion at the tip sides of the small diameter cylindrical portion and the first cylindrical portion.

[0010] In the present invention, the nozzle body is preferably formed with two second body-side flow paths and two third body-side flow paths, and the second body-side flow paths and the third body-side flow paths are alternately arranged at a pitch of 90° with respect to the axis of the large diameter tube portion formed in a cylindrical shape. With this configuration, it is possible to suppress the deviation of the turbulent flow generated between the outer circumferential surface of the small diameter tube portion and the inner circumferential surface of the first tube portion in the circumferential direction of the small diameter tube portion. Therefore, it is possible to more efficiently mix the wood gas injected from the opening at the tip of the small diameter tube portion and the mixed gas injected from between the outer circumferential surface of the small diameter tube portion and the inner circumferential surface of the first tube portion at the tip side of the small diameter tube portion and the first tube portion.

[0011] In the present invention, it is preferable that the auxiliary fuel gas flowing through one of the two main body-side third flow paths is hydrogen gas, and the auxiliary fuel gas flowing through the other main body-side third flow path is propane gas. According to the inventor's study, this configuration makes it easier to combust wood gas in a gas combustor using the injection nozzle of the present invention. Effect of the Invention

[0017] As described above, in a gas combustor using the injection nozzle of the present invention, wood gas can be easily combusted. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic diagram for explaining a configuration of a power generation system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram for explaining the configuration of the gas combustor shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view of the injection nozzle shown in FIG. [Figure 4] 4(A) is a side view of the nozzle body shown in FIG. 3, and (B) is a cross-sectional view taken along the line EE of (A). [Diagram 5] 4(A) is a side view of the cap member shown in FIG. 3, and (B) is a cross-sectional view taken along the line FF of (A). [Figure 6] 5(B) is a cross-sectional view taken along line GG of FIG. 5(B). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] (Configuration of power generation system, gasification furnace and gas combustor) Fig. 1 is a schematic diagram for explaining the configuration of a power generation system 1 according to an embodiment of the present invention. Fig. 2 is a schematic diagram for explaining the configuration of a gas combustor 5 shown in Fig. 1.

[0021] The power generation system 1 of this embodiment includes a gasifier 2, a boiler 3, and a generator 4. The gasifier 2 carbonizes wood chips to generate wood gas from the wood chips. The wood chips of this embodiment are wood chips made of wood crushed into chips. The size of the wood chips is about several mm. The wood gas generated in the gasifier 2 is supplied to the boiler 3. Specifically, the wood gas generated in the gasifier 2 is supplied to the boiler 3 as is. The boiler 3 burns the wood gas to generate steam. The boiler 3 includes a gas combustor 5 for burning the wood gas, etc. The generator 4 is supplied with the steam generated in the boiler 3. The generator 4 includes a steam turbine 6 that rotates by the steam generated in the boiler 3, etc.

[0022] The gasifier 2 includes a gasifier body 12 in which a primary combustion chamber 10 and a secondary combustion chamber 11 are formed, and a partition member 13 disposed inside the gasifier body 12. The partition member 13 divides the interior of the gasifier body 12 in the vertical direction. In the gasifier body 12, the upper side of the partition member 13 inside the gasifier body 12 serves as the primary combustion chamber 10, and the lower side of the partition member 13 inside the gasifier body 12 serves as the secondary combustion chamber 11. Wood chips are supplied to the primary combustion chamber 10 from above. In the primary combustion chamber 10, the wood chips are heated, for example, at about 300 to 600°C, and a char made of the carbonized wood chips and a primary generated gas are generated.

[0023] The partition member 13 is, for example, a punched metal, and has a plurality of passage holes formed therein through which the carbide generated in the primary combustion chamber 10 passes toward the secondary combustion chamber 11. The carbide generated in the primary combustion chamber 10 passes through the passage holes of the partition member 13 by its own weight and falls into the secondary combustion chamber 11. In the secondary combustion chamber 11, the carbide generated in the primary combustion chamber 10 is heated, for example, at about 1000 to 1200°C. The secondary combustion chamber 11 is supplied with the primary generated gas generated in the primary combustion chamber 10. In the secondary combustion chamber 11, wood gas is generated using the carbide and the primary generated gas. Compressed air may be supplied to the secondary combustion chamber 11.

[0024] The gasifier 2 also includes a chip storage section 14 that stores wood chips to be supplied to the gasifier body 12, an extraction pipe 15 for extracting wood gas generated in the secondary combustion chamber 11, and a supply pipe 16 for supplying the primary generated gas generated in the primary combustion chamber 10 to the secondary combustion chamber 11. The chip storage section 14 is disposed on the upper side of the gasifier body 12. Wood chips are supplied to the chip storage section 14 from above. Specifically, wood chips crushed by a crusher are supplied to the chip storage section 14 from above by a conveyor or the like. The wood chips stored in the chip storage section 14 are sequentially supplied to the gasifier body 12 under their own weight.

[0025] The extraction pipe 15 is disposed between the secondary combustion chamber 11 and the gas burner 5. One end of the extraction pipe 15 is connected to the upper surface side of the secondary combustion chamber 11. The extraction pipe 15 is routed from the secondary combustion chamber 11 toward the upper side, and a part of the extraction pipe 15 is disposed inside the primary combustion chamber 10 and inside the chip storage section 14. The wood gas extracted from the secondary combustion chamber 11 passes through a part of the extraction pipe 15 disposed inside the primary combustion chamber 10 and inside the chip storage section 14. A blower is disposed midway along the extraction pipe 15 to send the wood gas generated in the secondary combustion chamber 11 to the gas burner 5.

[0026] The supply pipe 16 is disposed between the primary combustion chamber 10 and the secondary combustion chamber 11. A blower 17 is disposed in the middle of the supply pipe 16 to send the primary generated gas generated in the primary combustion chamber 10 to the secondary combustion chamber 11. One end of the supply pipe 16 is connected to the secondary combustion chamber 11 from the outer periphery of the secondary combustion chamber 11 so that the primary generated gas is supplied in the tangential direction of the inner wall of the secondary combustion chamber 11. Therefore, in the secondary combustion chamber 11, the carbide and the primary generated gas swirl. That is, in the secondary combustion chamber 11, the carbide and the primary generated gas are burned while swirling.

[0027] As described above, the boiler 3 includes the gas combustor 5. The gas combustor 5 is installed in the combustion chamber of the boiler 3, and the boiler 3 generates steam by heat generated in the gas combustor 5. The gas combustor 5 includes a metal outer cylinder 20 formed in a cylindrical shape with a bottom, a metal inner cylinder 21 formed in a cylindrical shape with a bottom and disposed inside the outer cylinder 20, a ceramic member 22 made of ceramic and disposed inside the inner cylinder 21, and an injection nozzle 23 that injects wood gas (i.e., wood gas generated from wood chips) supplied from the gasification furnace 2 toward the inside of the inner cylinder 21. The outer cylinder 20 and the injection nozzle 23 are fixed to a frame (not shown) of the gas combustor 5. The gas combustor 5 also includes an ignition mechanism (not shown) for igniting the wood gas.

[0028] The outer cylinder 20 is formed of, for example, stainless steel. The outer cylinder 20 includes a cylindrical outer cylinder portion 20a and an outer bottom portion 20b that closes one end of the outer cylinder portion 20a. The outer cylinder 20 of this embodiment is formed in a bottomed cylindrical shape. That is, the outer cylinder portion 20a is formed in a cylindrical shape, and the outer bottom portion 20b is formed in a disk shape. A large number of through holes 20c are formed in the outer cylinder portion 20a and the outer bottom portion 20b. That is, the outer cylinder 20 is formed with a large number of through holes 20c. The through holes 20c are, for example, circular holes.

[0029] The inner cylinder 21 is formed of, for example, stainless steel. The inner cylinder 21 includes a cylindrical inner cylinder portion 21a and an inner bottom portion 21b that closes one end of the inner cylinder portion 21a. In this embodiment, the inner cylinder 21 is formed in a bottomed cylindrical shape, the inner cylinder portion 21a is formed in a cylindrical shape, and the inner bottom portion 21b is formed in a disk shape. The outer diameter of the inner cylinder portion 21a is smaller than the inner diameter of the outer cylinder portion 20a. A large number of through holes 21c are formed in the inner cylinder portion 21a and the inner bottom portion 21b. That is, a large number of through holes 21c are formed in the inner cylinder 21. The through holes 21c are, for example, round holes. The inner cylinder 21 is fixed to a frame (not shown) of the gas combustor 5 via the outer cylinder 20.

[0030] The inner cylinder 21 is inserted into the outer cylinder 20 so that the inner bottom 21b is disposed on the outer bottom 20b side. That is, the opening of the inner cylinder 21 is disposed on the opening side of the outer cylinder 20. In this embodiment, the entire inner cylinder 21 is disposed inside the outer cylinder 20. A gap is formed between the outer cylinder 20a and the inner cylinder 21a. That is, a gap is formed between the inner peripheral surface of the outer cylinder 20a and the outer peripheral surface of the inner cylinder 21a. A gap is also formed between the outer bottom 20b and the inner bottom 21b. The ceramic member 22 is formed in a disk shape. A gap of a predetermined size is formed in the ceramic member 22. The ceramic member 22 is fixed to the inner bottom 21b. The ceramic member 22 is disposed at a position where the wood gas injected from the injection nozzle 23 collides.

[0031] The injection nozzle 23 is disposed on the opening side of the outer cylinder 20 and the inner cylinder 21. The injection nozzle 23 is also disposed outside the outer cylinder 20 and the inner cylinder 21. The injection nozzle 23 is connected to the extraction pipe 15, and is supplied with wood gas generated in the gasification furnace 2. As described above, the injection nozzle 23 injects the wood gas toward the inside of the inner cylinder 21. The specific configuration of the injection nozzle 23 will be described later.

[0032] The wood gas injected from the injection nozzle 23 collides with the ceramic member 22 arranged inside the inner cylinder 21, and then is injected from the through hole 21c of the inner cylinder 21 into the gap between the inner cylinder 21 and the outer cylinder 20. The wood gas injected into the gap between the inner cylinder 21 and the outer cylinder 20 is then injected from the through hole 20c of the outer cylinder 20 to the outside of the outer cylinder 20. The wood gas burns at least on the outside of the outer cylinder portion 20a and the outside of the outer bottom portion 20b. That is, in the gas combustor 5, the flame B is generated at least on the outside of the outer cylinder portion 20a and the outside of the outer bottom portion 20b. The flame B may also be generated inside the outer cylinder 20.

[0033] (Injection nozzle configuration) Fig. 3 is a cross-sectional view of the injection nozzle 23 shown in Fig. 2. Fig. 4(A) is a side view of the nozzle body 27 shown in Fig. 3, and Fig. 4(B) is a cross-sectional view of the EE cross section of Fig. 4(A). Fig. 5(A) is a side view of the cap member 28 shown in Fig. 3, and Fig. 5(B) is a cross-sectional view of the FF cross section of Fig. 5(A). Fig. 6 is a cross-sectional view of the GG cross section of Fig. 5(B).

[0034] As described above, the gas combustor 5 includes the injection nozzle 23. That is, the injection nozzle 23 is used in the gas combustor 5. The injection nozzle 23 is a multi-fluid nozzle. In addition to wood gas, compressed air and auxiliary fuel gas are supplied to the injection nozzle 23. In this embodiment, hydrogen gas and propane gas are supplied to the injection nozzle 23 as the auxiliary fuel gas. The injection nozzle 23 injects the wood gas mixed with the mixed gas of the auxiliary fuel gas and the compressed air toward the inside of the inner tube 21. That is, the injection nozzle 23 injects the gas mixed with the mixed gas of the hydrogen gas, propane gas, and compressed air into the main component wood gas toward the inside of the inner tube 21.

[0035] The injection nozzle 23 includes a cylindrical nozzle body 27 having a flow path 27a formed at the center through which wood gas flows, a cylindrical cap member 28 fixed to the tip side of the nozzle body 27, and an annular fixing member 29 fixed to the nozzle body 27. The axis of the cylindrical nozzle body 27, the axis of the cylindrical cap member 28, and the axis of the annular fixing member 29 coincide with each other.

[0036] In the following description, the axial direction of the injection nozzle 23 is the left-right direction. Moreover, the X1 direction side in FIG. 3, etc., which is one side of the left-right direction, is the "left" side, and the X2 direction side in FIG. 3, etc., which is the opposite side, is the "right" side. The left-right direction is the axial direction of the nozzle body 27 formed in a cylindrical shape, and is also the axial direction of the cap member 28 formed in a cylindrical shape. In this embodiment, the left end of the injection nozzle 23 is the tip of the injection nozzle 23. Moreover, the left end of the nozzle body 27 is the tip of the nozzle body 27, and the left end of the cap member 28 is the tip of the cap member 28.

[0037] In the following description, the radial direction of the injection nozzle 23 is referred to as the "radial direction" and the circumferential direction of the injection nozzle 23 is referred to as the "circumferential direction". The radial direction of the injection nozzle 23 is also the radial direction of the nozzle body 27 and the cap member 28. The radial direction of the injection nozzle 23 is also the radial direction of a small diameter cylindrical portion 27b and a large diameter cylindrical portion 27c, which constitute a part of the nozzle body 27, and a first cylindrical portion 28a and a second cylindrical portion 28b, which constitute a part of the cap member 28, which will be described later. The circumferential direction of the injection nozzle 23 is also the circumferential direction of the nozzle body 27 and the cap member 28, and is also the circumferential direction of the small diameter cylindrical portion 27b, the large diameter cylindrical portion 27c, the first cylindrical portion 28a, and the second cylindrical portion 28b.

[0038] The nozzle body 27 includes a cylindrical small diameter cylindrical portion 27b constituting the tip (left end) of the nozzle body 27, a cylindrical large diameter cylindrical portion 27c having an outer diameter larger than that of the small diameter cylindrical portion 27b, and a square cylindrical fixed portion 27d fixed to the frame (not shown) of the gas combustor 5. The large diameter cylindrical portion 27c is connected to the right end of the small diameter cylindrical portion 27b. The fixed portion 27d is connected to the right end of the large diameter cylindrical portion 27c. The nozzle body 27 of this embodiment is composed of the small diameter cylindrical portion 27b, the large diameter cylindrical portion 27c, and the fixed portion 27d. The axis of the small diameter cylindrical portion 27b, the axis of the large diameter cylindrical portion 27c, and the axis of the fixed portion 27d are aligned.

[0039] The inner circumference of the small diameter cylinder portion 27b, the large diameter cylinder portion 27c, and the fixed portion 27d forms a flow path 27a. The flow path 27a penetrates the nozzle body 27 in the left-right direction. One end of the flow path 27a opens at the left end (tip) of the small diameter cylinder portion 27b, and the other end of the flow path 27a opens at the right end of the fixed portion 27d. Wood gas generated in the gasification furnace 2 flows into the flow path 27a from the right side. That is, the wood gas flows into the injection nozzle 23 from the opening at the right end of the fixed portion 27d. The opening at the left end of the small diameter cylinder portion 27b is an injection port for injecting the wood gas. That is, in the injection nozzle 23, the wood gas is injected from the opening at the tip of the small diameter cylinder portion 27b. The flow path 27a in this embodiment is a first flow path on the main body side.

[0040] The outside diameter of the small diameter cylindrical portion 27b is constant. On the other hand, the large diameter cylindrical portion 27c is formed in a stepped cylindrical shape, and the outside diameter of the large diameter cylindrical portion 27c is not constant. The large diameter cylindrical portion 27c is composed of a cylindrical first large diameter cylindrical portion 27e constituting the left end of the large diameter cylindrical portion 27c, a cylindrical second large diameter cylindrical portion 27f having an outside diameter larger than that of the first large diameter cylindrical portion 27e, and a cylindrical third large diameter cylindrical portion 27g having an outside diameter larger than that of the second large diameter cylindrical portion 27f. The first large diameter cylindrical portion 27e is connected to the right end of the small diameter cylindrical portion 27b. The second large diameter cylindrical portion 27f is connected to the right end of the first large diameter cylindrical portion 27e, and the third large diameter cylindrical portion 27g is connected to the right end of the second large diameter cylindrical portion 27f.

[0041] The outer peripheral surface of the first large diameter cylindrical portion 27e is formed with a male thread that engages with a female thread formed on the inner peripheral surface of the cap member 28. The outer peripheral surface of the second large diameter cylindrical portion 27f is formed with a male thread that engages with a female thread formed on the inner peripheral surface of the fixing member 29. The inner diameter of the large diameter cylindrical portion 27c is constant. The inner diameter of the small diameter cylindrical portion 27b is also constant. The inner diameter of the large diameter cylindrical portion 27c is equal to the inner diameter of the small diameter cylindrical portion 27b.

[0042] The nozzle body 27 is formed with two flow paths 27h through which compressed air flows, one flow path 27j through which hydrogen gas flows, and one flow path 27j through which propane gas flows. That is, the nozzle body 27 is formed with two flow paths 27h through which compressed air flows, and two flow paths 27j through which auxiliary fuel gas flows. The flow path 27h in this embodiment is the main body side second flow path. The flow path 27j in this embodiment is the main body side third flow path, and the auxiliary fuel gas flowing through one of the two main body side third flow paths is hydrogen gas, and the auxiliary fuel gas flowing through the other main body side third flow path is propane gas.

[0043] The flow paths 27h and 27j are formed radially outward of the flow path 27a. One end of the flow paths 27h and 27j opens at the outer peripheral surface of the large diameter cylindrical portion 27c. Specifically, one end of the flow paths 27h and 27j opens at the outer peripheral surface of the third large diameter cylindrical portion 27g. The other end of the flow paths 27h and 27j opens at a step surface 27k formed at the boundary between the small diameter cylindrical portion 27b and the large diameter cylindrical portion 27c (more specifically, the boundary between the small diameter cylindrical portion 27b and the first large diameter cylindrical portion 27e) on the outer peripheral side of the nozzle body 27. The flow paths 27h and 27j are alternately arranged at a pitch of 90° with respect to the axis of the large diameter cylindrical portion 27c formed in a cylindrical shape.

[0044] The flow passages 27h, 27j are composed of a linear radial flow passage 27p extending from the outer circumferential surface of the third large diameter cylindrical portion 27g toward the inside in the radial direction, and a linear axial flow passage 27r extending from the radial inner end of the radial flow passage 27p toward the left side. That is, one end of the flow passages 27h, 27j and the other end of the flow passages 27h, 27j are disposed at the same position in the circumferential direction, and the cross-sectional shape of the flow passages 27h, 27j is L-shaped as shown in FIG. 4(B) and the like. The radial flow passage 27p and the axial flow passage 27r are round holes. In this embodiment, the inner diameter of the radial flow passage 27p is larger than the inner diameter of the axial flow passage 27r.

[0045] A compressed air supply device (not shown) is connected to an opening at one end of the flow passage 27h formed on the outer peripheral surface of the third large-diameter cylindrical portion 27g via a pipe. The compressed air supplied to the flow passage 27h flows out from an opening at the other end of the flow passage 27h formed on the step surface 27k. A hydrogen gas supply device (not shown) is connected to an opening at one end of one flow passage 27j formed on the outer peripheral surface of the third large-diameter cylindrical portion 27g via a pipe, and a propane gas supply device (not shown) is connected to an opening at one end of the other flow passage 27j formed on the outer peripheral surface of the third large-diameter cylindrical portion 27g via a pipe. The hydrogen gas and propane gas supplied to the flow passage 27j flow out from the opening at the other end of the flow passage 27j formed on the step surface 27k.

[0046] The cap member 28 includes a cylindrical first cylindrical portion 28a disposed on the outer periphery of the small diameter cylindrical portion 27b of the nozzle body 27, and a cylindrical second cylindrical portion 28b fixed to the large diameter cylindrical portion 27c. The first cylindrical portion 28a constitutes the left end (tip) of the cap member 28. The second cylindrical portion 28b is connected to the right end of the first cylindrical portion 28a. The cap member 28 of this embodiment is constituted by the first cylindrical portion 28a and the second cylindrical portion 28b. The axis of the first cylindrical portion 28a and the axis of the second cylindrical portion 28b coincide with each other. The inner diameter of the first cylindrical portion 28a is smaller than the inner diameter of the second cylindrical portion 28b.

[0047] The outer diameter and inner diameter of the second cylindrical portion 28b are constant. An internal thread is formed on the inner peripheral surface of the second cylindrical portion 28b to engage with an external thread formed on the outer peripheral surface of the first large diameter cylindrical portion 27e. The internal thread on the inner peripheral surface of the second cylindrical portion 28b engages with the external thread on the outer peripheral surface of the first large diameter cylindrical portion 27e, thereby fixing the cap member 28 to the nozzle body 27. A step surface 28c formed on the inner peripheral side of the cap member 28 at the boundary between the first cylindrical portion 28a and the second cylindrical portion 28b is in contact with the step surface 27k of the nozzle body 27 at a predetermined contact pressure.

[0048] In the cap member 28, there are formed an annular flow passage 28d into which the compressed air and auxiliary fuel gas (i.e., compressed air, hydrogen gas, and propane gas) flowing out from the openings at the other ends of the flow passages 27h and 27j of the nozzle main body 27 flow, and a plurality of flow passages 28e leading from the flow passage 28d to the inner circumferential surface of the first cylindrical portion 28a. In this embodiment, eight flow passages 28e are formed in the cap member 28. In this embodiment, the flow passage 28d is a cap-side first flow passage, and the flow passage 28e is a cap-side second flow passage.

[0049] The flow path 28d is formed so as to be recessed from the step surface 28c toward the left side. That is, the flow path 28d is formed so as to be recessed from the step surface 28c toward the first cylindrical portion 28a side. The flow path 28d is formed from the right end of the first cylindrical portion 28a to the middle position in the left-right direction of the first cylindrical portion 28a. The shape of the flow path 28d when viewed from the left-right direction (i.e., the shape of the flow path 28d when viewed from the axial direction of the cap member 28 formed in a cylindrical shape) is annular. The center of curvature of the flow path 28d when viewed from the left-right direction coincides with the axis of the cap member 28.

[0050] The outer side surface of the flow passage 28d in the radial direction is disposed radially inward from the outer end of the axial flow passage 27r in the radial direction, and the inner side surface of the flow passage 28d in the radial direction is disposed radially outward from the inner end of the axial flow passage 27r in the radial direction. The part of the first tube portion 28a disposed radially inward from the flow passage 28d is a cylindrical inner first tube portion 28f. The right end surface of the inner first tube portion 28f is disposed leftward from the step surface 28c.

[0051] The outer peripheral surface of the first cylindrical portion 28a is an inclined surface that is inclined radially inward as it moves to the left (i.e., toward the tip side of the cap member 28). The left end of the inner peripheral surface of the first cylindrical portion 28a is an inclined surface 28g that is inclined radially outward as it moves to the left. The inner diameter of the first cylindrical portion 28a is constant except for the inclined surface 28g. The inner diameter of the first cylindrical portion 28a is larger than the outer diameter of the small diameter cylindrical portion 27b. A gap is formed between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a over the entire circumferential area. The inner peripheral surface of the first cylindrical portion 28a is disposed slightly outward in the radial direction from the inner end of the axial flow passage 27r in the radial direction. The left end surface of the first cylindrical portion 28a is disposed at the same position in the left-right direction as the left end surface of the small diameter cylindrical portion 27b, or is disposed slightly to the left of the left end surface of the small diameter cylindrical portion 27b.

[0052] The flow passage 28e is a round hole. One end of the flow passage 28e is connected to the flow passage 28d. The other end of the flow passage 28e opens on the inner peripheral surface of the first cylindrical portion 28a. Specifically, the other end of the flow passage 28e opens on the inner peripheral surface of the inner first cylindrical portion 28f. One end of the flow passage 28e and the other end of the flow passage 28e are arranged at the same position in the left-right direction. In addition, one end of the flow passage 28e and the other end of the flow passage 28e are offset in the circumferential direction. The flow passage 28e in this embodiment is formed in a spiral shape, and the shape of the flow passage 28e when viewed from the left-right direction is curved. The eight flow passages 28e are arranged at a constant pitch in the circumferential direction. That is, the eight flow passages 28e are arranged at a pitch of 45° with respect to the axis of the first cylindrical portion 28a.

[0053] In the injection nozzle 23, the compressed air, hydrogen gas, and propane gas flowing out from the openings at the other ends of the flow paths 27h and 27j of the nozzle body 27 pass through flow path 28d, then through flow path 28e, and flow into the space between the outer circumferential surface of the small diameter cylindrical portion 27b and the inner circumferential surface of the first cylindrical portion 28a. In this embodiment, the compressed air, hydrogen gas, and propane gas flowing out from the openings at the other ends of the flow paths 27h and 27j flow into the annular flow path 28d, making it possible to mix the compressed air, hydrogen gas, and propane gas in the flow path 28d.

[0054] As described above, the right end surface of the first inner cylindrical portion 28f is disposed to the left of the step surface 28c, and a gap is formed between the right end surface of the first inner cylindrical portion 28f and the step surface 27k, so that the other ends of the flow paths 27h, 27j also directly communicate with the outer circumferential surface of the small diameter cylindrical portion 27b and the inner circumferential surface of the first cylindrical portion 28a. Therefore, the compressed air, hydrogen gas, and propane gas flowing out from the openings at the other ends of the flow paths 27h, 27j also directly flow into the gap between the outer circumferential surface of the small diameter cylindrical portion 27b and the inner circumferential surface of the first cylindrical portion 28a.

[0055] The compressed air, hydrogen gas, and propane gas that flow between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a are mixed between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a, and are injected from between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a at the left end side of the small diameter cylindrical portion 27b and the first cylindrical portion 28a. That is, in the injection nozzle 23, a mixed gas of the compressed air, hydrogen gas, and propane gas is injected from between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a at the tip side of the small diameter cylindrical portion 27b and the first cylindrical portion 28a, and an injection port for injecting the mixed gas is formed between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a at the tip of the injection nozzle 23.

[0056] As described above, since one end of the flow passage 28e and the other end of the flow passage 28e are offset in the circumferential direction, the mixed gas injected from between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a at the tip of the injection nozzle 23 swirls in a roughly spiral shape. The mixed gas injected from between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a at the tip of the injection nozzle 23 is mixed with the wood gas injected from the opening at the tip of the small diameter cylindrical portion 27b at the tip of the injection nozzle 23. The gas injected from the injection nozzle 23 (i.e., the wood gas mixed with the mixed gas) is in the form of a fine mist due to the action of the compressed air. Also, the gas injected from the injection nozzle 23 swirls in a roughly spiral shape. That is, the flow of the gas injected from the injection nozzle 23 is a vortex flow.

[0057] (Main effects of this form) As described above, in the injection nozzle 23 of this embodiment, the cap member 28 includes the first cylindrical portion 28a disposed on the outer circumferential side of the small diameter cylindrical portion 27b of the nozzle body 27, and the cap member 28 is formed with an annular flow path 28d into which the compressed air, hydrogen gas, and propane gas flowing out from the openings at the other ends of the flow paths 27h and 27j formed in the nozzle body 27 flow, and eight flow paths 28e leading from the flow path 28d to the inner circumferential surface of the first cylindrical portion 28a. In this embodiment, one end of the flow path 28e is connected to the flow path 28d, and the other end of the flow path 28e opens at the inner circumferential surface of the first cylindrical portion 28a.

[0058] Therefore, in this embodiment, the compressed air, hydrogen gas, and propane gas that have passed through the flow path 28e flow out toward the inner periphery of the first cylindrical portion 28a. Therefore, in this embodiment, the compressed air, hydrogen gas, and propane gas that have passed through the flow path 28e collide with the outer periphery of the small diameter cylindrical portion 27b, and a turbulent flow can be efficiently generated between the outer periphery of the small diameter cylindrical portion 27b and the inner periphery of the first cylindrical portion 28a. As a result, in this embodiment, the wood gas injected from the opening at the tip of the small diameter cylindrical portion 27b and the mixed gas injected from the tip of the injection nozzle 23 between the outer periphery of the small diameter cylindrical portion 27b and the inner periphery of the first cylindrical portion 28a can be efficiently mixed. Therefore, according to the study by the inventor of the present application, the gas combustor 5 using the injection nozzle 23 of this embodiment can easily burn the wood gas.

[0059] In this embodiment, the other ends of the flow paths 27h and 27j are also directly connected between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a, and the compressed air, hydrogen gas, and propane gas flowing out from the openings at the other ends of the flow paths 27h and 27j also flow directly between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a. Therefore, in this embodiment, the compressed air, hydrogen gas, and propane gas flowing in between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a toward the inner peripheral side of the first cylindrical portion 28a, and the compressed air, hydrogen gas, and propane gas flowing directly in between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a toward the tip side of the injection nozzle 23, can generate a more complex turbulent flow between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a. Therefore, in this embodiment, it is possible to more efficiently mix the wood gas sprayed from the opening at the tip of the small diameter cylindrical portion 27b and the mixed gas sprayed from between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a at the tip of the injection nozzle 23.

[0060] In this embodiment, in the nozzle body 27, the flow passage 27h through which the compressed air flows and the flow passage 27j through which the hydrogen gas or the propane gas flows are alternately arranged at a pitch of 90° with respect to the axis of the large diameter cylindrical portion 27c. Therefore, in this embodiment, it is possible to suppress the deviation in the circumferential direction of the turbulent flow generated between the outer circumferential surface of the small diameter cylindrical portion 27b and the inner circumferential surface of the first cylindrical portion 28a. Therefore, in this embodiment, it is possible to more efficiently mix the wood gas injected from the opening at the tip of the small diameter cylindrical portion 27b with the mixed gas injected from the tip of the injection nozzle 23 between the outer circumferential surface of the small diameter cylindrical portion 27b and the inner circumferential surface of the first cylindrical portion 28a.

[0061] In this embodiment, the gas burner 5 includes an outer cylinder 20, an inner cylinder 21 disposed inside the outer cylinder 20, and a ceramic member 22 disposed inside the inner cylinder 21. In this embodiment, gaps are formed between the outer cylinder 20a and the inner cylinder 21a, and between the outer bottom 20b and the inner bottom 21b. In this embodiment, a large number of through holes 20c are formed in the outer cylinder 20a and the outer bottom 20b, and a large number of through holes 21c are formed in the inner cylinder 21a and the inner bottom 21b, so that the flame B is generated at least outside the outer cylinder 20a and outside the outer bottom 20b. Therefore, according to the study by the inventor of the present application, the gas burner 5 of this embodiment can burn wood gas more easily.

[0062] In this embodiment, the ceramic member 22 disposed inside the inner cylinder 21 acts to reduce the moisture content of the wood gas inside the inner cylinder 21. In this embodiment, the heated ceramic member 22 acts to suppress a temperature drop inside the inner cylinder 21. Furthermore, in this embodiment, the wood gas ejected from the through hole 21c of the inner cylinder 21 is retained in the gap between the inner cylinder 21 and the outer cylinder 20, thereby suppressing a temperature drop in the gap between the inner cylinder 21 and the outer cylinder 20.

[0063] In this embodiment, the action of the wood gas ejected from the through-hole 21c of the inner cylinder 21 creates turbulence in the wood gas stagnating in the gap between the inner cylinder 21 and the outer cylinder 20, stirring the wood gas stagnating in the gap between the inner cylinder 21 and the outer cylinder 20, and the stirred and homogenized wood gas is ejected from the through-hole 20c of the outer cylinder 20 and burned outside the outer cylinder portion 20a and outside the outer bottom portion 20b. It is presumed that this combination of effects makes it easier to combust wood gas in the gas combustor 5 in this embodiment.

[0064] In this embodiment, hydrogen gas and propane gas are supplied to the injection nozzle 23 as auxiliary fuel gas. Therefore, according to the study by the present inventor, in this embodiment, wood gas can be more easily combusted in the gas combustor 5 using the injection nozzle 23. Also, in this embodiment, since the ceramic member 22 is fixed to the inner bottom portion 21b, it becomes possible to easily position and fix the ceramic member 22 arranged inside the inner cylinder 21.

[0065] (Other embodiments) In the above-mentioned embodiment, the outer diameter of the large diameter cylindrical portion 27c of the nozzle body 27 may be constant. Also, in the above-mentioned embodiment, one end of the flow passage 28e of the cap member 28 and the other end of the flow passage 28e may be shifted in the left-right direction. Also, in the above-mentioned embodiment, the flow passage 28e may be formed in a straight line. Furthermore, in the above-mentioned embodiment, the number of the flow passages 28e formed in the cap member 28 may be a plurality of seven or less, or may be nine or more. Also, in the above-mentioned embodiment, the other ends of the flow passages 27h, 27j may not directly communicate between the outer peripheral surface of the small diameter cylindrical portion 27b and the inner peripheral surface of the first cylindrical portion 28a.

[0066] In the above-mentioned embodiment, one end of the flow passages 27h, 27j and the other end of the flow passages 27h, 27j may be shifted in the circumferential direction. In the above-mentioned embodiment, three or more flow passages 27h through which compressed air flows may be formed in the nozzle body 27. In the above-mentioned embodiment, two or more flow passages 27j through which hydrogen gas flows may be formed in the nozzle body 27, or two or more flow passages 27j through which propane gas flows may be formed in the nozzle body 27. In the above-mentioned embodiment, either one of hydrogen gas and propane gas does not have to be supplied to the injection nozzle 23.

[0067] In the above-mentioned embodiment, the ceramic member 22 may be fixed to the inner cylinder portion 21a directly or via a predetermined member. In this case, a gap may be formed between the ceramic member 22 and the inner bottom portion 21b. In the above-mentioned embodiment, a part of the inner cylinder 21 may be disposed outside the outer cylinder 20. In the above-mentioned embodiment, one end of the extraction pipe 15 may be connected to a side surface of the secondary combustion chamber 11, or only one combustion chamber may be formed inside the gasification furnace body 12. [Explanation of symbols]

[0068] 1. Power generation system 2 Gasifier 3. Boiler 4. Generator 5 Gas Burner 6. Steam Turbine 20 Outer cylinder 20a Outer cylinder part 20b outer bottom 20c through hole 21 Inner cylinder 21a Inner cylinder part 21b Inner bottom 21c through hole 22 Ceramic components 23 Injection nozzle 27 Nozzle body 27a Flow path (first flow path on the main body side) 27b Small diameter cylinder part 27c Large diameter cylinder 27h Flow path (Main body side second flow path) 27j Flow path (main body side third flow path) 27k step surface 28 Cap member 28a 1st cylinder part 28b Second cylinder part 28c step surface 28d Flow path (cap side first flow path) 28e Flow path (cap side second flow path)

Claims

1. An injection nozzle used in a gas burner for burning wood gas generated from wood chips, A cylindrical nozzle body having a first flow passage on a main body side through which the wood gas flows formed at its center, and a cylindrical cap member fixed to a tip side of the nozzle body, the nozzle body includes a cylindrical small diameter portion constituting a tip end of the nozzle body, and a cylindrical large diameter portion connected to the small diameter portion and having an outer diameter larger than that of the small diameter portion, The nozzle body is formed with a second body-side flow passage through which compressed air flows and a third body-side flow passage through which auxiliary fuel gas flows, one end of the second body-side flow passage and one end of the third body-side flow passage open at an outer circumferential surface of the large diameter cylindrical portion, and the other end of the second body-side flow passage and the other end of the third body-side flow passage open at a step surface formed at a boundary portion between the small diameter cylindrical portion and the large diameter cylindrical portion on the outer circumferential side of the nozzle body, the cap member includes a cylindrical first cylindrical portion disposed on an outer circumferential side of the small diameter cylindrical portion, and a cylindrical second cylindrical portion connected to the first cylindrical portion and fixed to the large diameter cylindrical portion, The inner diameter of the first cylindrical portion is smaller than the inner diameter of the second cylindrical portion, the cap member is formed with an annular cap-side first flow passage into which the compressed air and the auxiliary fuel gas flowing out from an opening at the other end of the main body-side second flow passage and an opening at the other end of the main body-side third flow passage flow in, and a plurality of cap-side second flow passages leading from the cap-side first flow passage to an inner circumferential surface of the first cylindrical portion, the cap-side first flow path is formed so as to be recessed from a step surface formed at a boundary portion between the first cylindrical portion and the second cylindrical portion on the inner circumferential side of the cap member toward the first cylindrical portion, and the shape of the cap-side first flow path when viewed in an axial direction of the cylindrically formed cap member is annular, one end of the cap side second flow path is connected to the cap side first flow path, and the other end of the cap side second flow path opens on an inner circumferential surface of the first cylindrical portion, and the one end of the cap side second flow path and the other end of the cap side second flow path are offset from each other in a circumferential direction of the first cylindrical portion, The wood gas is injected from the opening at the tip of the small diameter cylindrical portion, an injection nozzle configured to inject a mixed gas of the compressed air and the auxiliary fuel gas from between an outer peripheral surface of the small diameter cylindrical portion and an inner peripheral surface of the first cylindrical portion at the tip side of the small diameter cylindrical portion and the first cylindrical portion.

2. the other end of the second body-side flow passage and the other end of the third body-side flow passage also directly communicate with an outer circumferential surface of the small diameter cylindrical portion and an inner circumferential surface of the first cylindrical portion, 2. The injection nozzle according to claim 1, wherein the compressed air and the auxiliary fuel gas flowing out from the opening at the other end of the main body side second flow passage and the opening at the other end of the main body side third flow passage also directly flow into a gap between an outer peripheral surface of the small diameter cylindrical portion and an inner peripheral surface of the first cylindrical portion.

3. The nozzle body is formed with two of the second body-side flow paths and two of the third body-side flow paths, 3. The injection nozzle according to claim 1, wherein the second body-side flow passage and the third body-side flow passage are alternately arranged at a pitch of 90 degrees with respect to an axis of the large-diameter tubular portion which is formed in a cylindrical shape.

4. 4. The injection nozzle according to claim 3, wherein the auxiliary fuel gas flowing through one of the two main body side third flow paths is hydrogen gas, and the auxiliary fuel gas flowing through the other main body side third flow path is propane gas.

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