COMBUSTION ENGINES AND GAS TURBINE

Abstract

Internal combustion engines (10), including: a combustion lining (11); a premixing tube (20) arranged upstream of the combustion lining (11) in an axial direction of the combustion lining (11) and containing a screw passage (23) extending in a circumferential direction of the combustion lining (11), and an axial passage (25) extending in the axial direction of the combustion lining (11) to connect the screw passage (23) to an interior of the combustion lining (11); a first fuel nozzle (31) which is arranged upstream of the screw passage (23) in the circumferential direction and has an injection opening (31a) for injecting fuel into the screw passage (23); and a housing (45, 70) in which the premixing tube (20) is arranged, wherein the injection opening (31a) is arranged at a position which overlaps in the axial direction of the combustion lining (11) with an area in which the screw passage (23) exists, wherein the premixing tube (20) has a tangential passage (21) which is connected to an end section (11a, 11b, 23a, 25a, 25b, 41a) of the screw passage (23) on a circumferentially upstream side and extends in a tangential direction of a screw at the end section (11a, 11b, 23a, 25a, 25b, 41a), and wherein the injection port (31a) is arranged upstream of the tangential passage (21), and wherein the tangential passage (21) is configured such that air can enter the housing (45, 70) from an inlet end section of the tangential passage (21).

Description

TECHNICAL AREA

[0001] The present disclosure relates to an internal combustion engine and a gas turbine. BACKGROUND

[0002] Small gas turbines, also known as micro gas turbines, can be used for a variety of applications, such as private power generation in shops and hospitals, as range extenders in electric vehicles, as portable power sources, etc.

[0003] In such a small gas turbine, it is desirable to provide a premixing chamber upstream of a combustion chamber in order to premix air and fuel and thus improve exhaust gas performance (see e.g. patent document 1). Citation list for patent literature

[0004] Patent document 1: JP H10 - 26 351 A SUMMARY Problems to be solved

[0005] In the gas turbine described in patent document 1, a premixing chamber extending along the axial direction of the combustion chamber is provided on the side of the cylindrical combustion chamber, and the fuel is injected from downstream to upstream in the axial direction of the combustion chamber. In other words, in the gas turbine described in patent document 1, the combustion chamber and the premixing chamber are arranged radially to the combustion chamber, which tends to increase the dimensions of the combustion chamber in the radial direction.

[0006] For example, when considering the use of a gas turbine as a range extender in an electric vehicle or portable power source, it is desirable to keep the gas turbine as small as possible. One way to reduce the size of the gas turbine is to reduce the size of the combustion engine.

[0007] In light of the above, one objective of at least one embodiment of the present invention is to reduce the size of the combustion engine.

[0008] US 3,667,221 A relates to a device for premixing air and fuel or for vaporizing air before introducing it into the primary zone of a burner. The device has a housing that defines a swirl chamber within it. The swirl chamber is designed to receive air and fuel, vaporize and / or atomize the fuel, and deliver the air and fuel as a swirl into the burner.

[0009] US 3,618,317 A relates to a device for introducing fuel into a combustion chamber. The device comprises a housing with a downstream end wall in which a core outlet is formed, the housing defining a swirl chamber around and radially outside the core outlet, the core outlet being capable of establishing a flow connection between the swirl chamber and the combustion chamber. The device also includes means for receiving and directing compressed air and fuel into the swirl chamber. The swirl chamber is designed to utilize the energy of the compressed air to circulate the air and fuel around the core outlet and to generate a primary swirl discharge flow of air from the core outlet. This entrains fuel in the primary swirl flow and expels it from the outlet in a highly dispersed manner.

[0010] US Patent 2006 / 0218932A1 relates to a method for generating a swirling flow of low-fuel, premixed fuel and air without guiding the flow through swirl blades. A fuel supply is mixed with a sufficient quantity of air to form a low-fuel mixture. The mixture is directed tangentially into an annular flow channel, creating a spiral flow without recirculation of the main flow. The spiral flow of fuel and air is then directed into a combustion chamber.

[0011] US 2014 / 0318129A1 relates to a combustion chamber for burning an air-fuel mixture. The combustion chamber comprises an outer shell and a flame tube located within the outer shell, the outer shell and the flame tube forming an annular channel between them. The flame tube has flow openings that penetrate its shell and connect the annular channel to the interior of the flame tube. The combustion chamber also includes a fuel nozzle extending within the flame tube to supply fuel to the flame tube.

[0012] GB 2 444 737 A relates to a burner for a gas turbine engine, comprising a swirling device for providing a swirling mixture of air and fuel and a combustion chamber for burning the swirling fuel-air mixture. Solution to the problems

[0013] The invention is defined in the independent claims. The following sections of the description and drawings relating to aspects not covered by the claims are not presented as aspects of the invention, but rather as background information or examples intended to aid in understanding the invention.

[0014] (1) An internal combustion chamber according to at least one embodiment of the present invention comprises: a combustion liner; a premixing tube arranged upstream of the combustion liner in an axial direction and having a screw passage extending in a circumferential direction of the combustion liner, and an axial passage extending in the axial direction of the combustion liner to connect the screw passage to an interior of the combustion liner; and a first fuel nozzle arranged upstream of the screw passage in the circumferential direction and having an injection orifice for injecting fuel into the screw passage. The injection orifice is arranged at a position that overlaps axially with a region in which the screw passage exists.

[0015] According to the above configuration (1), the premix tube and the first fuel nozzle do not need to be located on the side of the combustion liner, thus preventing the combustion chamber from becoming larger in the radial direction of the combustion liner, thereby reducing the size of the combustion chamber.

[0016] (2) In some embodiments, in the above configuration (1), the screw passage is shaped such that a region of a flow passage cross-section along a radial direction of the combustion lining gradually decreases from upstream in the circumferential direction to downstream in the circumferential direction.

[0017] According to the configuration above (2), even if the air-fuel mixture mixed in the screw passage flows into the combustion liner through the axial passage, and thus the flow rate of the air-fuel mixture in the screw passage gradually decreases downstream in the circumferential direction, the reduction in the flow velocity of the air-fuel mixture flowing through the screw passage in the circumferential direction is suppressed, since the cross-sectional area of ​​the screw passage also gradually decreases downstream in the circumferential direction. This makes it difficult to achieve differences in the flow velocity of the air-fuel mixture flowing through the axial passage into the combustion liner depending on the circumferential positioning.Accordingly, it is possible to suppress differences in the combustion state within the combustion liner depending on its circumferential position. As a result, the combustion state within the combustion liner is improved, which contributes to an increase in the combustion efficiency of the internal combustion engine.

[0018] (3) In some embodiments, in the above configuration (2), the screw passage is shaped such that a central position of a flow passage cross-section moves downstream along the radial direction of the combustion lining in the axial direction of the combustion lining, while the screw passage extends from upstream in the circumferential direction to downstream in the circumferential direction.

[0019] In the configuration (3) above, which includes the configuration (2) above, the screw passage is shaped such that the flow cross-sectional area decreases gradually from upstream to downstream along the radial direction of the combustion liner. Therefore, if the screw passage is not shaped such that the center position of the flow cross-sectional area moves downstream in the axial direction of the combustion liner as the screw passage extends from upstream to downstream in the circumferential direction, the position of the connection between the screw passage and the axial passage moves upstream in the axial direction of the combustion liner as it extends from upstream to downstream in the circumferential direction.If the position of the connection varies in the axial direction depending on the circumferential position, the length of the axial passage varies along the axial direction depending on the circumferential position, so that the flow velocity of the air-fuel mixture flowing through the axial passage varies depending on the circumferential position, and the flow rate of the air-fuel mixture flowing from the axial passage to the combustion lining can vary depending on the circumferential position.

[0020] In the configuration described above (3), the screw passage is shaped such that the mean position of the flow passage cross-section moves downstream along the radial direction of the combustion lining in the axial direction of the combustion lining as the screw passage extends from upstream in the circumferential direction to downstream in the circumferential direction. This prevents the position of the connection between the screw passage and the axial passage from moving upstream in the axial direction of the combustion lining as it extends from upstream in the circumferential direction to downstream in the circumferential direction.Therefore, according to the configuration above (3), it is difficult to have differences in the flow rate of the air-fuel mixture flowing through the axial passage into the combustion liner depending on the circumferential position, and it is possible to suppress differences in the combustion state in the combustion liner depending on the circumferential position. As a result, the combustion state in the combustion liner is improved, which contributes to improving the combustion efficiency of the internal combustion engine.

[0021] (4) In some embodiments in one of the above configurations (1) to (3), the premixing tube has a tangential passage that is connected to an end section of the screw passage on an upstream side in the circumferential direction and extends in a tangential direction along the screw at the end section. The injection port is located upstream of the tangential passage.

[0022] According to the configuration above (4), the flow is straightened as the fuel and air flow through the tangential passage, which makes it more difficult for turbulence to occur in the fuel-air mixture flow in the screw passage. As a result, the turbulence of the air-fuel mixture flow into the combustion liner through the axial passage is suppressed, and the combustion conditions in the combustion liner are improved, which contributes to improving the combustion efficiency of the internal combustion engine.

[0023] (5) In some embodiments, in one of the above configurations (1) to (4), the injection hole is arranged at a distance from an end section of the screw passage on an upstream side in the circumferential direction along a tangential direction of a screw at the end section, such that the distance is within twice the diameter of the screw passage at the end section.

[0024] According to the above configuration (5), the position of the fuel nozzle can be positioned closer to the radial inside of the combustion liner, so that the combustion chamber can be reduced in size.

[0025] (6) In some embodiments in one of the above configurations (1) to (5), the axial passage is formed in an annular shape along the circumferential direction. The combustion chamber further comprises a spark plug arranged in a central region which is annularly surrounded by the axial passage from a radially outer side in order to ignite an air-fuel mixture of fuel and air supplied from the premix tube into the combustion liner.

[0026] According to the configuration above (6), as the air-fuel mixture flows into the combustion liner through the annular axial passage, a circulating flow is generated on the axially upstream side of the combustion liner. This causes the air-fuel mixture to flow upstream in the axial direction in a region radially inward of the axial passage. In the configuration above (6), the circulating air-fuel mixture can be ignited because the spark plug is located in the central region, which is annularly surrounded by the axial passage on its radially outer side. In the region where the circulating air-fuel mixture is generated as described above, the flow velocity of the air-fuel mixture is relatively slow. Therefore, igniting the circulating flow as in the configuration above (6) improves the reliability of the ignition.

[0027] (7) In some embodiments, in the configuration (6) above, the combustion chamber also includes a cooling air passage located on one side of the spark plug in the central region, through which cooling air flows to cool the spark plug.

[0028] According to the above configuration (7) it is possible to reduce the adverse effect of the flame heat on the spark plug.

[0029] In some embodiments, the combustion chamber in the above configuration (6) or (7) further comprises a second fuel nozzle arranged in the central region to supply the fuel to the combustion lining.

[0030] According to the above configuration (8), by supplying fuel from the second fuel nozzle into the combustion lining at the time of ignition by the spark plug, the concentration of fuel near the spark plug can be increased, thus improving ignitability.

[0031] (9) In some embodiments, in one of the configurations (1) to (8) above, the combustion chamber further comprises an outer cylinder part which faces an outer circumferential surface of the combustion liner at a distance from the outer circumferential surface. The outer cylinder part comprises a first region which faces the outer circumferential surface at a first distance, and a second region which is located downstream of the first region and which faces the outer circumferential surface at a second distance which is less than the first distance.

[0032] According to the configuration above (9), the combustion liner can be cooled by directing cooling air into a gap between the combustion liner and the first region and the second region of the outer cylinder part. Since the second gap is smaller than the first, the flow velocity of the cooling air flowing in the gap between the combustion liner and the second region is higher than the flow velocity of the cooling air flowing in the gap between the combustion liner and the first region. Consequently, the region of the combustion liner facing the second region with the second gap can be effectively cooled.

[0033] (10) In some embodiments, the outer cylinder part in the above configuration (9) comprises a third region located downstream of the second region and facing the outer circumferential surface at a third distance greater than the second distance. The combustion lining has a plurality of opening sections formed in a region facing the third region.

[0034] According to the configuration above (10), cooling air can be supplied to the combustion liner through the opening sections by flowing into a space between the combustion liner and the outer cylinder part. This allows the temperature within the combustion liner to be kept higher in the axial direction in a region upstream of the opening sections than in a region downstream of the opening sections. This stabilizes the combustion state in the axial direction in the region upstream of the opening sections, while suppressing the combustion gas temperature in the axial direction in the region downstream of the opening sections.

[0035] The air flowing through the opening sections into the combustion lining has a velocity component towards the downstream side in the axial direction of the combustion lining (hereinafter referred to as the axial velocity component) and a velocity component towards the inner side in the radial direction of the combustion lining (hereinafter referred to as the radial velocity component).

[0036] The flow velocity of the air flowing from the space between the third region and the combustion lining through the opening sections is determined by the opening area of ​​each opening section, the number of opening sections, and the volume of air flowing into the combustion lining per unit time. Therefore, if the volume of air is constant, an increase in the flow velocity of the cooling air flowing in the space between the third region and the combustion lining—that is, an increase in the axial velocity component at that space—increases the axial velocity component of the air flowing through the opening sections into the combustion lining, but decreases the radial velocity component.Conversely, reducing the axial velocity component of the cooling air flowing in the space between the third region and the combustion lining reduces the axial velocity component of the air flowing through the opening sections into the combustion lining, but increases the radial velocity component.

[0037] In cases where the turbine is located downstream of the combustion lining, it is desirable to suppress the temperature variation of the combustion gas reaching the turbine in order to improve turbine efficiency. Therefore, it is desirable to increase the penetrating force of the air flowing through the opening sections into the combustion lining against the combustion gas flowing within the combustion lining by increasing the radial velocity component of the air flowing through the opening sections into the combustion lining. It is therefore desirable to decrease the axial velocity component of the cooling air flowing in the space between the third region and the combustion lining.

[0038] According to the configuration above (10), since the third distance is larger than the second distance, the flow velocity of the cooling air flowing in the distance between the combustion lining and the third region is lower than the flow velocity of the cooling air flowing in the distance between the combustion lining and the second region. Accordingly, it is possible to reduce the axial velocity component of the cooling air flowing in the distance between the third region and the combustion lining, and thus increase the penetration force.

[0039] (11) In some embodiments in one of the above configurations (1) to (10), the combustion liner has a plurality of cutout sections extending axially from an axially downstream end section of the combustion liner and spaced at intervals along the circumferential direction. The combustion liner further comprises a retaining element that presses the end section of the combustion liner from a radially outer or inner side of the combustion liner in order to retain the end section.

[0040] According to the configuration (11) above, the axially downstream end section of the combustion lining can be held by the retaining part with a simple configuration.

[0041] (12) In some embodiments, the combustion chamber in one of the above configurations (1) to (11) further comprises a flow guide arranged upstream of the screw passage in the circumferential direction to straighten air flowing into the screw passage.

[0042] According to the configuration above (12), the flow guide suppresses differences in the flow rate of the air flowing through the screw passage depending on the position of the flow passage cross-section along the radial direction of the combustion lining. This makes it possible to suppress differences in the mixture state of fuel and air in the screw passage depending on the position of the flow cross-section.

[0043] (13) In some embodiments, the combustion chamber in one of the above configurations (1) to (12) further comprises a housing in which the premixing tube is arranged. The housing has an air inlet section for supplying air into the housing and a side wall section that covers the premixing tube from a radially outer side of the combustion lining and includes the air inlet section. An inlet end of the premixing tube is arranged in a region within the housing on a side opposite an axis of the combustion lining from a region in which the air inlet section is positioned.

[0044] According to the configuration above (13), the area near the inlet end of the premix tube is less likely to be affected by the flow velocity of the air entering the casing through the air inlet section, making it difficult to observe differences in the air-fuel mixture flow in the screw passage. As a result, differences in the air-fuel mixture flow into the combustion liner through the axial passage are suppressed, and the combustion condition in the combustion liner is improved, contributing to an improvement in the combustion efficiency of the internal combustion engine.

[0045] (14) In some embodiments, in the above configuration (13) the injection hole is located in the region on the opposite side.

[0046] According to the above configuration (14), the fuel and air are efficiently mixed in the screw passage in combination with the effect of configuration (13).

[0047] (15) In some embodiments, in one of the configurations (1) to (14) above, the axial passage has a cylindrical outer wall section arranged on a radially outer side of the combustion liner and a cylindrical inner wall section arranged on a radially inner side at a distance in a radial direction of the combustion liner from the outer wall section. At least the outer wall section and the inner wall section are shaped such that one dimension in the radial direction gradually increases as the outer wall section extends downstream in the axial direction in a downstream region of the axial passage.

[0048] According to the configuration above (15), since the air-fuel mixture flows into the combustion liner through the axial passage with a velocity component towards the outside in the radial direction, a circulating flow is readily generated on the axially upstream side of the combustion liner, such that the air-fuel mixture flows upstream in the axial direction radially inwards in a region of the axial passage. In the region where such a circulating flow of the air-fuel mixture is generated, the flow velocity of the air-fuel mixture is relatively slow, so that the conditions suitable for maintaining the flame can be achieved.

[0049] (16) A gas turbine according to at least one embodiment of the present invention comprises: the combustion chamber according to one of the above configurations (1) to (15); a compressor for generating compressed air; and a turbine configured to be set in rotation by a combustion gas from the combustion chamber.

[0050] According to the above configuration (16), the gas turbine can be reduced in size because the combustion engine is included according to one of the above configurations (1) to (15). Beneficial effects

[0051] According to at least one embodiment of the present invention, it is possible to reduce the size of the gas turbine. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is an overall configuration diagram of a power generation device with a gas turbine according to some embodiments. Fig. Figure 2 is a schematic side view of an internal combustion engine according to some embodiments. Fig. Figure 3 is a schematic diagram of the appearance of an internal combustion chamber according to some embodiments, seen from upstream in the axial direction of a combustion lining. Fig. Figure 4 is a schematic cross-sectional view taken along line IV-IV in Fig. 3. Fig. 5 is a schematic cross-sectional view taken along line VV in Fig. 2. Fig. Figure 6 is a schematic enlarged view of the area around the premixing tube in Fig. 4. Fig. Figure 7 is a schematic cross-sectional view of an upstream end section of the premixing tube according to some embodiments, taken along the axial direction of the premixing tube. Fig. Figure 8 is a schematic cross-sectional view to describe a cooling air passage. DETAILED DESCRIPTION

[0052] Embodiments of the present invention are now described in detail with reference to the accompanying drawings. However, it is intended that dimensions, materials, shapes, relative positions, and the like of components described in the embodiments are to be understood as illustrative only and do not serve to limit the scope of the present invention unless specifically indicated.

[0053] For example, an expression for a relative or absolute arrangement such as "in a direction", "along a direction", "parallel", "orthogonal", "centered", "concentric" and "coaxial" is not to be interpreted as only denoting the arrangement in a strictly literal sense, but also as including a state in which the arrangement is shifted relative to the other by a tolerance or by an angle or a distance, making it possible to achieve the same function.

[0054] For example, the terms "equal", "identical" and "uniform" should not be understood as indicating only the state in which the characteristic is strictly the same, but also a state in which there is a tolerance or a difference with which the same function can still be achieved.

[0055] Furthermore, a shape such as a rectangular shape or a cylindrical shape is not only to be understood as the geometrically strict shape, but also includes a shape with irregularities or chamfered corners within the area in which the same effect can be achieved.

[0056] On the other hand, expressions such as "comprise", "include", "exhibit", "contain" and "represent" are not to be understood as excluding other components. (Overall configuration)

[0057] Fig. Figure 1 is an overall configuration diagram of a power generation device comprising a gas turbine according to some embodiments. The in Fig. The energy generation device shown in Figure 1 is used, for example, as a range extender in an electric vehicle or as a portable power source. The device shown in Figure 1 is used, for example, as a range extender in an electric vehicle or as a portable power source. Fig. The energy generation device 1 shown in Figure 1 comprises a gas turbine 2, a generator 7, and a heat exchanger 9. According to some embodiments, the gas turbine 2 comprises a compressor 3 for generating compressed air, a combustion chamber 10 for generating combustion gas using the compressed air and the fuel, and a turbine 5 configured to be set in rotation by the combustion gas.

[0058] A compressor wheel (not shown) of the compressor 3, according to some embodiments, is connected to a turbine wheel of the turbine 5 via a rotating shaft 8A. The compressor 3 is set in rotation by the rotational energy of the turbine 5 to generate compressed air. The compressed air generated by the compressor 3 is supplied to the combustion chamber 10 via the heat exchanger 9, which will be described later. In some embodiments, a portion of the compressed air generated by the compressor 3 is not supplied to the combustion chamber 10 via the heat exchanger 9, as will be described in detail later. The compressor 3, according to some embodiments, can, for example, be a centrifugal compressor.

[0059] According to some embodiments, the combustion chamber 10 is supplied with fuel and compressed air generated by the compressor 3 and heated by the heat exchanger 9. It burns the fuel to produce combustion gas, which serves as the working fluid for the turbine 5. The combustion gas is subsequently fed to the turbine 5 from the combustion chamber 10. A detailed embodiment of the combustion chamber 10 according to some embodiments will be described later.

[0060] According to some embodiments, the turbine 5 can, for example, be a turbine with a radial turbine wheel or a mixed-flow turbine wheel (not shown). According to some embodiments, the turbine 5 is driven by the combustion gas produced by the combustion engine 10. In some embodiments, the turbine wheel (not shown) of the turbine 5 is connected to the generator 7 via a rotating shaft 8B. In other words, according to some embodiments, the generator 7 is configured to generate electricity from the rotational energy of the turbine 5.

[0061] The combustion gas expelled by turbine 5 is fed to the heat exchanger 9. In some embodiments, the heat exchanger 9 is configured to exchange heat between the combustion gas emitted by turbine 5 and the compressed air supplied by compressor 3. In other words, in the heat exchanger 9, according to some embodiments, the compressed air supplied by compressor 3 is heated by the combustion gas emitted by turbine 5. (Internal combustion engine 10)

[0062] Fig. Figure 2 is a schematic side view of the combustion engine 10 according to some embodiments. Fig. Figure 3 is a schematic representation of the appearance of the combustion chamber 10 according to some embodiments, seen from upstream in the axial direction of a combustion lining 11. Fig. Figure 4 is a schematic cross-sectional view taken along line IV-IV in Fig. 3. Fig. 5 is a schematic cross-sectional view taken along line VV in Fig. 2. Fig. Figure 6 is a schematic enlarged view of the area around the premixing tube 20. Fig. 4.

[0063] The combustion chamber 10 according to some embodiments comprises a combustion liner 11 with a cylindrical shape, a premixing tube 20 arranged upstream of the combustion liner 11 in the axial direction of the combustion liner 11, a first fuel nozzle 31, a second fuel nozzle 35 and a spark plug 41. The combustion chamber 10 according to some embodiments includes a housing 70 in which the premixing tube 20 is arranged, and an outer cylinder part 80 which is located opposite the outer circumferential surface of the combustion liner 11 at a distance from the outer circumferential surface.

[0064] In the following description, the direction of the axis AX of the combustion lining 11 is referred to as the axial direction of the combustion lining 11 or simply as the axial direction. The circumferential direction of the combustion lining 11 is also referred to simply as the circumferential direction. The radial direction of the combustion lining 11 is also referred to simply as the radial direction. Furthermore, the axial direction upstream along the flow direction of the combustion gas is referred to as upstream in the axial direction or axially upstream. Similarly, the axial direction downstream along the flow direction of the combustion gas is referred to as downstream in the axial direction or axially downstream. (Combustion lining 11)

[0065] As described above, the combustion lining 11, according to some embodiments, has a cylindrical shape and is open at both ends in the axial direction. The combustion lining 11, according to some embodiments, has an axially downstream end section 11a, which is held by a retaining element 90 (see Fig. 4) Although not shown in the figure, according to some embodiments, the combustion liner 11 is attached, for example, to an external cylinder part 80 near an axially upstream end section 11b. The external cylinder part 80 is a cylindrical element that is positioned at a distance from the outer circumferential surface 11c of the combustion liner 11. The downstream side of the combustion liner 11 is connected to the turbine 5.

[0066] The compressed air can flow through a gap between the combustion lining 11 and the outer cylinder part 80, as described below, but details will be explained later. (Premixing tube 20)

[0067] In some embodiments, the premixing tube 20, as described above, is arranged axially upstream of the combustion lining 11. According to some embodiments, the premixing tube 20 comprises a screw passage 23 extending circumferentially to the combustion lining 11 and an axial passage 25 extending axially to connect the screw passage 23 to the interior of the combustion lining 11. Furthermore, according to some embodiments, the premixing tube 20 comprises a tangential passage 21 circumferentially connected to an end section 23a of the screw passage 23 on the upstream side and extending tangentially to the screw at the end section 23a.The tangential direction of the screw means the direction of a tangent to the axis AXs, which passes through the centers Cs of the flow cross-sections of the screw passage 23 along the radial direction of the combustion lining 11. The center Cs of the flow cross-section is the centroid of the flow cross-section.

[0068] In some embodiments, as well as in Fig. As shown in Figure 5, the inlet end of the premixing tube 20, i.e., the inlet end section 21a, is located on the upstream side of the tangential passage 21, in a region 70b inside the housing 70 on the opposite side of the axis AX of the combustion lining 11 from region 70a, where the air inlet section 71, which will be described later, is positioned.

[0069] In some embodiments, the screw passage 23 is shaped such that the area of ​​the flow passage cross-section gradually decreases along the radial direction of the combustion lining 11 from upstream in the circumferential direction to downstream in the circumferential direction.

[0070] As in Fig. As well illustrated in Figure 6, the axial passage 25 is, in some embodiments, a flow passage formed in an annular shape along the circumferential direction. In some embodiments, an axially upstream end section 25a of the axial passage 25 is connected to an annular opening section 23b in the axially downstream wall of the screw passage 23. In some embodiments, an axially downstream end section 25b of the axial passage 25 is an annular opening section and is located in an axially upstream region of the combustion lining 11.

[0071] As in Fig. As can be clearly seen in Figure 6, the axial passage 25 in some embodiments has a cylindrical outer wall section 26, which is arranged on the radially outer side, and a cylindrical inner wall section 27, which is arranged on the radially inner side at a distance in the radial direction of the combustion lining 11 from the outer wall section 26.

[0072] In some embodiments, the outer wall section 26 and the inner wall section 27 are shaped such that the dimension gradually increases in the radial direction, while extending downstream in the axial direction in a downstream region of the axial passage 25.

[0073] At least the outer wall section 26 of the outer wall section 26 and the inner wall section 27 can be shaped such that the dimension in the radial direction gradually increases as they extend downstream in the axial direction in a downstream region of the axial passage 25.

[0074] As in Fig. As well illustrated in Figure 6, in some embodiments a conical wall section 28 is shaped such that its diameter widens downstream in the axial direction from the outer wall section 26. In some embodiments, the downstream end section of the conical wall section 28 is spaced radially away from the inner circumferential surface 11d of the combustion lining 11.

[0075] As in Fig. As well illustrated in Figure 6, the premixing tube 20, according to some embodiments, comprises an inner cylindrical section 24 that extends radially in the axial direction within a region inside the screw passage 23. The inner cylindrical section 24 includes a portion of the wall surface that forms the screw passage 23 and the inner wall section 27 of the axial passage 25. In some embodiments, the region inside the inner cylindrical section 24 is the region that is annularly surrounded by the axial passage 25 from its radially outer side. This region is also referred to as the central region 24a.

[0076] In some embodiments, the spark plug 41, the cooling air passage 43 and the second fuel nozzle 35 are arranged in the central region 24a. (Spark plug 41, cooling air passage 43 and second fuel nozzle 35)

[0077] In some embodiments, the spark plug 41 is a spark plug arranged in the central region 24a for igniting the air-fuel mixture of fuel and air supplied from the premixing tube 20 into the combustion lining 11. In some embodiments, the spark plug 41 is arranged in the central region 24a at the axially downstream end section of the inner cylindrical section 24, i.e., at the axially downstream end section of the inner wall section 27 of the axial passage 25.

[0078] The cooling air passage 43 is an air passage located on the side of the spark plug 41 in the central region 24a, through which cooling air flows to cool the spark plug 41. Details of the cooling air passage 43 will be described later.

[0079] In some embodiments, the combustion chamber may have a second fuel nozzle 35 located in the central region 24a to supply fuel to the combustion lining 11.

[0080] By supplying fuel from the second fuel nozzle 35 into the combustion lining 11 at the time of ignition by the spark plug 41, the concentration of fuel near the spark plug 41 can be increased, thus improving the ignitability.

[0081] The second fuel nozzle 35 is connected to a fuel supply line 37 to supply fuel to the second fuel nozzle 35, as shown in the Fig. 4 and Fig. 6 shown. (Flow guidance 51)

[0082] Fig. Figure 7 is a schematic cross-sectional view of an upstream end section of the premixing tube 20 according to some embodiments, taken along the axial direction of the premixing tube 20.

[0083] In some embodiments, the combustion chamber includes a flow guide 51 which is arranged upstream of the screw passage in the circumferential direction in order to straighten the air flowing into the screw passage.

[0084] In some embodiments, the flow guide 51 is arranged near the inlet end section 21a on the upstream side of the tangential passage 21.

[0085] The flow guide 51, for example, is a short tubular element with a bell-shaped opening, the radius of which increases upstream with increasing inner circumferential area.

[0086] The flow guide 51 suppresses differences in the flow velocity of the compressed air flowing through the screw passage 23 as a function of the position of the flow passage cross-section along the radial direction of the combustion lining 11. This makes it possible to suppress differences in the mixture state of fuel and air in the screw passage 23 as a function of the position of the flow cross-section. (First fuel injector 31)

[0087] The first fuel nozzle 31, according to some embodiments, is arranged circumferentially upstream of the screw passage 23. The first fuel nozzle 31, according to some embodiments, has an injection opening 31a for injecting fuel into the screw passage 23. Fig. For example, in figures 5 to 7 only one injection opening 31a is shown in the first fuel injector 31, but the number of injection openings 31a can be one, two or more. (Housing 70)

[0088] In some embodiments, the combustion chamber comprises a housing 70 in which the premixing tube 20 is arranged. According to some embodiments, the housing 70 has an air inlet section 71 for supplying compressed air from the compressor 3 into the housing 70, a side wall section 73 that covers the premixing tube 20 from the radially outer side of the combustion lining 11 and partially forms the air inlet section 71, and a pair of wall sections 75 that cover the premixing tube 20 from the axially outer side of the combustion lining 11.

[0089] The axially downstream wall section 75 of the pair of wall sections 75 has an opening section 75a. In some embodiments, the region inside the housing 70 is connected to the region inside the combustion lining 11 by the opening section 75a. Furthermore, in some embodiments, the region inside the housing 70 is connected to the region surrounded by the inner circumferential surface 80a of the outer cylinder part 80 and the outer circumferential surface 11c of the combustion lining 11 by the opening section 75a.

[0090] In some embodiments, the conical wall section 28 is arranged such that it protrudes downstream in an axial direction from the opening section 75a. (Overview of the flow of compressed air, air-fuel mixture and combustion gas)

[0091] The approximate flow of the compressed air, the air-fuel mixture and the combustion gas in the combustion chamber 10 according to some embodiments configured as such is mainly described with reference to Fig. 4 described.

[0092] The compressed air supplied by the compressor 3 and heated by the heat exchanger 9 flows through the air inlet section 71 into the housing 70, as shown by arrow a1 in Fig. 4 shown. The compressed air entering the housing 70 flows between the premixing tube 20 and the pair of wall sections 75, mainly as shown by arrows a2 and a3.

[0093] The compressed air flowing between the premixing tube 20 and the axially downstream wall section 75 of the pair of wall sections 75 splits into a flow in the region surrounded by the inner circumferential surface 80a of the outer cylinder part 80 and the outer circumferential surface 11c of the combustion lining 11, as shown by arrows a4 and a7, a flow in the region surrounded by the inner circumferential surface 11d of the combustion lining 11 and the outer circumferential surface of the conical wall section 28, as shown by arrows a5 and a8, and a flow towards the inlet side of the premixing tube 20, as shown by arrows a6, a9 and a10. Furthermore, the compressed air flows between the premixing tube 20 and the axially upstream wall section 75 of the pair of wall sections 75 to the inlet side of the premixing tube 20, as shown by the arrows a2, a11 and a12.

[0094] As in Fig. As shown in Figure 7, the compressed air flowing to the inlet side of the premixing tube 20 flows into the tangential passage 21 of the premixing tube 20 from the inlet 51a on the upstream side of the flow guide 51 through the flow guide 51, as shown by arrows a10 and a12, and also flows into the tangential passage 21 through the annular gap between the outer circumferential surface 51b of the flow guide 51 and the inner circumferential surface 21b of the tangential passage 21, as shown by arrows a9 and a11.

[0095] The fuel F injected from the injection opening 31a of the first fuel nozzle 31 and the compressed air flowing into the premixing tube 20 are premixed in the premixing tube 20, mainly in the screw passage 23, to form the fuel-air mixture.

[0096] The air-fuel mixture flowing in the screw passage 23 flows along the inner circumferential surface of the conical wall part 28 through the axial passage 25 (see Fig. 6), as indicated by arrow g1 in Fig. 4 shown. Part of the air-fuel mixture forms a circulating flow, as shown by arrow g5, and the remainder forms a circulating flow that flows into the combustion lining 11, as shown by arrow g2.

[0097] The air-fuel mixture is ignited by the spark plug 41 at the axially downstream end section of the inner cylindrical part 24 to generate the combustion gas, which flows downstream in the axial direction of the combustion lining 11, as indicated by arrow g3. The combustion gas is then drawn from the combustion lining 11 and enters the turbine 5, as indicated by arrow g4. (Position of injection port 31a)

[0098] In the combustion engine 10 according to some embodiments, as in Fig. As shown in Figure 7, the injection opening 31a is arranged in a position that overlaps in the axial direction with a region A in which the screw passage 23 is present.

[0099] As a result, the premixing tube 20 and the first fuel nozzle 31 do not need to be located on the side of the combustion lining 11, thus preventing the gas turbine 2 from becoming larger in the radial direction of the combustion lining 11, thereby making the gas turbine 2 smaller.

[0100] Since the first fuel nozzle 31 is located in the position described above, the fuel can be easily injected into the screw passage 23 along the tangential direction of the screw. This makes it more difficult for the fuel to adhere to the wall surface forming the screw passage 23. In this way, a backfire (re-ignition), in which the flame in the combustion lining 11 flashes back into the premix tube 20, can be suppressed.

[0101] Since the first fuel nozzle 31 is positioned at the location described above, the number of fuel nozzles can also be reduced. For example, in some of the embodiments described above, the number of fuel nozzles at the location described above can be one.

[0102] In the combustion engine 10 according to some embodiments, as well as in Fig. As shown in Figure 5, the premixing tube 20 comprises the tangential passage 21, which is connected to the end section 23a of the screw passage 23 on the upstream side in the circumferential direction and extends along the end section 23a in the tangential direction of the screw. Furthermore, in some embodiments of the combustion chamber 10, the injection opening 31a is arranged upstream of the tangential passage 21.

[0103] As a result, the flow is straightened as the fuel and air flow through the tangential passage 21, which makes it more difficult for differences in the flow of the fuel-air mixture to occur in the screw passage 23. Thus, differences in the mixing state of the fuel and air and in the flow rate of the air-fuel mixture into the combustion lining 11 through the axial passage 25 are suppressed, and the combustion state in the combustion lining 11 is improved, which contributes to improving the combustion efficiency of the gas turbine 2.

[0104] In the combustion engine 10 according to some embodiments, as in Fig. As shown in Figure 5, the injection hole 31a is arranged at a distance L from the end section 23a of the screw passage 23 on the upstream side in the circumferential direction along the tangential direction of the screw at the end section 23a, such that the distance L is within twice the (2D) diameter D of the screw passage at the end section 23a.

[0105] This allows the position of the first fuel nozzle 31 to be positioned closer to the radial inside of the combustion lining 11, thus reducing the size of the gas turbine 2. (Snail passage 23)

[0106] In some embodiments, the screw passage 23 is shaped as described above such that the area of ​​the flow passage cross-section gradually decreases along the radial direction of the combustion lining 11 from upstream in the circumferential direction to downstream in the circumferential direction.

[0107] In some embodiments, the axial passage 25 is an annular flow passage that extends over the entire circumference of the combustion liner 11 and is connected to the combustion liner 11, such that the air-fuel mixture flowing through the screw passage 23 gradually decreases as the screw passage 23 extends downstream in the circumferential direction. In some embodiments, the screw passage 23 is shaped, as described above, such that the area of ​​the flow passage cross-section gradually decreases along the radial direction of the combustion liner 11 from upstream in the circumferential direction to downstream in the circumferential direction.Accordingly, even if the air-fuel mixture flowing through the screw passage 23 gradually decreases as the screw passage 23 extends downstream in the circumferential direction, the reduction in the flow velocity of the air-fuel mixture flowing through the screw passage 23 in the circumferential direction is suppressed. Therefore, it is difficult to have differences in the flow velocity of the air-fuel mixture flowing through the axial passage 25 into the combustion lining 11 depending on the circumferential position, and it is possible to suppress differences in the combustion state in the combustion lining 11 depending on the circumferential position. This improves the combustion state in the combustion lining 11, which contributes to improving the combustion efficiency of the gas turbine 2.

[0108] In some embodiments, the screw passage 23 is shaped such that the position of the center Cs of the flow passage cross-section moves downstream along the radial direction of the combustion lining 11 in the axial direction of the combustion lining 11, while extending from upstream in the circumferential direction to downstream in the circumferential direction.

[0109] In some embodiments, the screw passage 23, as described above, is shaped such that the area of ​​the flow passage cross-section gradually decreases along the radial direction of the combustion lining 11 from upstream to downstream in the circumferential direction. Therefore, if the screw passage is not shaped such that the position of the center Cs of the flow passage cross-section moves downstream in the axial direction of the combustion lining 11 as it extends from upstream to downstream in the circumferential direction, the position of the connecting section 29 between the screw passage 23 and the axial passage 25, i.e.,The position of the connecting section 29 between the opening section 23b of the screw passage 23 and the end section 25a of the axial passage 25 is positioned upstream in the axial direction of the combustion lining 11, extending from upstream circumferentially to downstream circumferentially. If the position of the connecting section 29 varies depending on the circumferential position, the length of the axial passage 25 also varies along the axial direction depending on the circumferential position. Therefore, the flow velocity of the air-fuel mixture flowing through the axial passage 25 varies depending on the circumferential position, and the flow rate of the air-fuel mixture flowing from the axial passage 25 to the combustion lining 11 can also vary depending on the circumferential position.

[0110] In some embodiments, the screw passage 23, as described above, is shaped such that the position of the center Cs of the flow passage cross-section moves downstream along the radial direction of the combustion lining 11 in the axial direction of the combustion lining 11 as it extends from upstream in the circumferential direction to downstream in the circumferential direction. This prevents the position of the connecting section 29 from moving upstream in the axial direction of the combustion lining 11 as it extends from upstream in the circumferential direction to downstream in the circumferential direction.Therefore, according to some embodiments, it is difficult to have differences in the flow rate of the air-fuel mixture flowing through the axial passage 25 into the combustion lining 11, depending on the circumferential position, and it is possible to suppress differences in the combustion state in the combustion lining 11 depending on the circumferential position. This improves the combustion state in the combustion lining 11, which contributes to improving the combustion efficiency of the gas turbine 2. (arrangement of spark plug 41)

[0111] In some embodiments, the spark plug 41 is arranged in the central region 24a.

[0112] In some embodiments, since the flow passage from the axially downstream end section 25b of the annularly shaped axial passage 25 is abruptly enlarged on the axially upstream side of the combustion lining 11, as indicated by arrow g5 in Fig. As shown in Figure 4, a circulating flow is generated such that the air-fuel mixture flows upstream in the axial direction in a region radially inward of the axial passage 25. In some embodiments, the circulating flow of the air-fuel mixture described above can be ignited because the spark plug 41 is located in the central region 24a, which is annularly surrounded by the axial passage 25 on its radially outer side. In the region 11r, where the circulating flow of the air-fuel mixture is generated as described above, the flow velocity of the air-fuel mixture is relatively slow. Therefore, the reliability of the ignition is improved by igniting the circulating flow with the spark plug 41, which is located in the central region 24a. (Cooling air passage 43)

[0113] Fig. Figure 8 is a schematic cross-sectional view to describe the cooling air passage 43. As in Fig. 6 and Fig. As shown in Figure 8, in some embodiments the combustion chamber includes the cooling air passage 43, through which cooling air flows to cool the spark plug 41.

[0114] The cooling air passage 43 is formed inside a housing 45, which, for example, has a plurality of openings 45a on its wall surface. The housing 45 shapes the cooling air passage 43 such that the cooling air cools the area around an end section 41a of the spark plug 41 facing the interior of the combustion lining 11. The housing 45 is connected to a downstream end of a cooling air line 47 for supplying the cooling air.

[0115] In some embodiments, such as in Fig. As shown in Figure 1, the cooling air line 47 is configured such that it does not supply the compressed air from the compressor 3 to the cooling air passage 43 via the heat exchanger 9. It can be configured to supply the compressed air, which has passed through the heat exchanger 9 and is now heated, to the cooling air passage 43.

[0116] As indicated by arrow b1 in Fig. As shown in Figure 8, the compressed air (cooling air) flows from the compressor 3 through the cooling air line 47 into the cooling air passage 43, as indicated by arrow b2. The cooling air then flows through the interior of the housing 45, i.e., the cooling air passage 43, as indicated by arrow b3, and cools the spark plug 41 as it flows out of the housing 45, i.e., as it flows into the combustion lining 11 through the openings 45a, as indicated by arrow b4.

[0117] In this way it is possible to reduce the adverse effect of the flame heat in the combustion lining 11 on the spark plug 41.

[0118] By interrupting the supply of cooling air to the cooling air passage 43 during ignition and resuming the supply of cooling air to the cooling air passage 43 after ignition, it is possible to reduce the adverse effects of the flame heat on the spark plug 41 while maintaining the reliability of the ignition. (Flow of compressed air between combustion lining 11 and outer cylinder part 80)

[0119] As described above, in some embodiments the compressed air supplied via the housing 70 can flow into a space between the outer circumferential surface 11c of the combustion lining 11 and the inner circumferential surface 80a of the outer cylinder part 80, as indicated by arrows a4 and a7 in Fig. 4 shown.

[0120] Since the compressed air flows downstream in an axial direction between the outer circumferential surface 11c of the combustion lining 11 and the inner circumferential surface 80a of the outer cylinder part 80, the compressed air cools the combustion lining 11.

[0121] In some embodiments, the outer cylinder part 80 comprises a first region 81, which faces the outer circumferential surface 11c of the combustion lining 11 and has a first distance Δd1, and a second region 82, which is arranged downstream of the first region 81 and faces the outer circumferential surface 11c of the combustion lining 11 and has a second distance Δd2, which is smaller than the first distance Δd1.

[0122] In some embodiments, the combustion lining 11 can be cooled by directing compressed air (cooling air) into a gap between the combustion lining 11 and the first region 81 and the second region 82 of the outer cylinder part 80. Since the second gap Δd2 is smaller than the first gap Δd1, the flow velocity of the cooling air flowing in the gap between the combustion lining 11 and the second region 82 is higher than the flow velocity of the cooling air flowing in the gap between the combustion lining 11 and the first region 81. Accordingly, the region of the combustion lining 11 opposite the second region 82 with the second gap Δd2 can be effectively cooled.

[0123] In some embodiments, the outer cylinder part 80 comprises a third region 83, which is arranged downstream of the second region 82 and faces the outer circumferential surface 11c of the combustion lining 11 and has a third distance Δd3 which is greater than the second distance Δd2.

[0124] Furthermore, in some embodiments, the combustion lining 11 has a plurality of opening sections 13 formed in a region facing the third region 83.

[0125] Accordingly, in some embodiments, compressed air (cooling air) can be supplied to the combustion lining 11 through the opening sections 13 by flowing it at a distance between the combustion lining 11 and the outer cylinder part 80. In this way, the temperature within the combustion lining 11 can be kept higher in the axial direction in a region upstream of the opening sections 13 than in a region downstream of the opening sections 13. Thus, the combustion state can be stabilized in the axial direction in the region upstream of the opening sections 13, while the temperature of the combustion gas in the axial direction in the region downstream of the opening sections 13 can be suppressed.

[0126] The air flowing into the combustion lining 11 through the opening sections 13 has a velocity component towards the downstream side in the axial direction of the combustion lining 11 (hereinafter referred to as axial velocity component Vax) and a velocity component towards the inside in the radial direction of the combustion lining 11 (hereinafter referred to as radial velocity component Vd) (see Fig. 4).

[0127] The flow velocity of the air flowing from the distance between the third region 83 and the combustion lining 11 through the opening sections 13 into the combustion lining 11 is determined by the opening area of ​​each of the opening sections 13, the number of opening sections 13, and the volume of air flowing into the combustion lining 11 per unit time. Thus, if the volume of air is constant, an increase in the flow velocity of the cooling air flowing in the distance between the third region 83 and the combustion lining 11—that is, an increase in the axial velocity component at that distance—increases the axial velocity component Vax of the air flowing through the opening sections 13 into the combustion lining 11, but decreases the radial velocity component Vd.

[0128] Conversely, a reduction in the axial velocity component of the cooling air flowing in the space between the third region 83 and the combustion lining 11 reduces the axial velocity component Vax of the air flowing through the opening sections 13 into the combustion lining 11, but increases the radial velocity component Vd.

[0129] In the case where the turbine 5 is located downstream of the combustion lining 11, it is desirable to suppress the temperature fluctuations of the combustion gas reaching the turbine 5 in order to improve turbine efficiency and prevent damage. Therefore, it is desirable to increase the penetrating force of the air flowing through the opening sections 13 into the combustion lining 11 against the combustion gas flowing in the combustion lining 11 by increasing the radial velocity component Vd of the air flowing through the opening sections 13 into the combustion lining 11. It is therefore desirable to decrease the axial velocity component of the cooling air flowing in the space between the third region 83 and the combustion lining 11.

[0130] In some embodiments, the flow velocity of the cooling air flowing in the space between the combustion lining 11 and the third region 83 is lower than the flow velocity of the cooling air flowing in the space between the combustion lining 11 and the second region 82, since the third space Δd3 is larger than the second space Δd2. Accordingly, it is possible to reduce the axial velocity component of the cooling air flowing in the space between the third region 83 and the combustion lining 11, thereby increasing the penetration force. (Section of the axial downstream side of the combustion lining 11)

[0131] In the combustion engine 10 according to some embodiments, as in Fig. As shown in Figure 4, the combustion lining 11 has a plurality of cutout sections 15 which extend in the axial direction from the axially downstream end section 11a of the combustion lining 11 and are arranged at intervals along the circumferential direction.

[0132] Furthermore, in the combustion chamber 10, according to some embodiments, the retaining part 90 is configured such that it holds the end section 11a by pressing the end section 11a from the radially outer side of the combustion lining 11.

[0133] In particular, in the combustion chamber 10 according to some embodiments, the cutout sections 15 enable each of the axially downstream partial cylindrical sections 17 of the combustion lining 11, which are spaced apart in the circumferential direction and divided by the cutout sections 15, to move the end section 11a in the radial direction separately from the other partial cylindrical sections 17.

[0134] Therefore, if the combustion lining 11 is held by the retaining part 90 by moving the end section 11a inwards in a radial direction against the elastic force of the semi-cylindrical section 17, the semi-cylindrical section 17 pushes the retaining part 90 outwards in a radial direction due to the elastic force.

[0135] This allows the axially downstream end section 11a of the combustion lining 11 to be held by the retaining part 90 with a simple configuration.

[0136] Since the combustion lining 11 can be held by the retaining element 90 by utilizing the elasticity of the combustion lining 11 (partially cylindrical section 17), the vibration of the combustion lining 11 during combustion can be suppressed and the durability of the combustion lining 11 improved. Furthermore, the simple configuration reduces the cost increase.

[0137] The end section 11a can be held in place by pressing the end section 11a from the radial inner side of the combustion lining 11. (Positional relationship between the inlet end of the premixing tube 20 and the air inlet section 71 of the housing 70)

[0138] As described above, in some embodiments, as well as in Fig. 5 shown, the inlet end of the premixing tube 20, i.e. the inlet end section 21a on the upstream side of the tangential passage 21, in region 70b inside the housing 70 on the opposite side of the axis AX of the combustion lining 11 from region 70a, where the air inlet section 71 is positioned.

[0139] Consequently, the area near the inlet end of the premixing tube 20 is less likely to be affected by the uneven flow velocity distribution of the compressed air flowing through the air inlet section 71 into the casing 70, making it difficult to experience turbulence in the air-fuel mixture flow in the screw passage 23. As a result, the turbulence of the air-fuel mixture flow into the combustion liner 11 through the axial passage 25 is suppressed, and the combustion conditions in the combustion liner 11 are improved, contributing to an increase in the combustion efficiency of the gas turbine 2.

[0140] Furthermore, in some embodiments the injection opening 31a is arranged in region 70b on the opposite side.

[0141] As a result, the fuel and air in the screw passage 23 are efficiently mixed in combination with the effect of the configuration in which the inlet end section 21a is located on the upstream side of the tangential passage 21 in the region 70b on the opposite side. (Circulation flow of the air-fuel mixture)

[0142] As described above, in some embodiments, since the air-fuel mixture flows into the combustion lining 11 through the annular axial passage 25, on the axially upstream side of the combustion lining 11, as indicated by arrow g5 in Fig. 4 shows a circulating flow is generated so that the air-fuel mixture flows upstream in the axial direction in a region radially inwards of the axial passage 25.

[0143] Furthermore, in some embodiments as described above, the outer wall section 26 and the inner wall section 27 are shaped such that the dimension in the radial direction gradually increases as they extend downstream in the axial direction in a downstream region of the axial passage 25.

[0144] Since the air-fuel mixture flows through the axial passage 25 with a velocity component radially outward into the combustion lining 11, the circulating flow described above is readily generated on the axially upstream side of the combustion lining 11 in a region radially inward of the axial passage 25. In the region 11r where such a circulating flow of the air-fuel mixture is generated, the flow velocity of the air-fuel mixture is relatively slow, as described above, so that the conditions suitable for flame retention can be maintained.

[0145] The present invention is not limited to the embodiments described above, but includes modifications of the embodiments described above and embodiments consisting of combinations of these embodiments. List of reference symbols 1 Energy generating device 2 gas turbines 3 compressors 5 Turbine 10 internal combustion engines 11. Combustion lining 13 Opening section 15 Excerpt section 20 Premixing tube 21 Tangential passage 23 snail passage 24a Central Region 25 Axial passage 26 Outer wall section 27 Inner wall area 31 First fuel injector 31a Injection port 35 Second fuel injector 41 Spark plug 51 Flow guidance 70 cases 71 Air intake section 73 Side wall section 80 Outer cylinder part 81 First Region 82 Second Region 83 Third Region 90 Holding part

Claims

[1] Internal combustion engines (10), including: a combustion lining (11); a premixing tube (20) arranged upstream of the combustion lining (11) in an axial direction of the combustion lining (11) and containing a screw passage (23) extending in a circumferential direction of the combustion lining (11), and an axial passage (25) extending in the axial direction of the combustion lining (11) to connect the screw passage (23) to an interior of the combustion lining (11); a first fuel nozzle (31) which is arranged upstream of the screw passage (23) in the circumferential direction and has an injection opening (31a) for injecting fuel into the screw passage (23); and a housing (45, 70) in which the premixing tube (20) is arranged, wherein the injection opening (31a) is arranged at a position which overlaps in the axial direction of the combustion lining (11) with an area in which the screw passage (23) exists, wherein the premixing tube (20) has a tangential passage (21) which is connected to an end section (11a, 11b, 23a, 25a, 25b, 41a) of the screw passage (23) on a circumferentially upstream side and extends in a tangential direction of a screw at the end section (11a, 11b, 23a, 25a, 25b, 41a), and wherein the injection port (31a) is arranged upstream of the tangential passage (21), and wherein the tangential passage (21) is configured such that air can enter the housing (45, 70) from an inlet end section of the tangential passage (21). [2] Combustion chamber (10) according to claim 1, wherein the screw passage (23) is shaped such that a region of a flow passage cross-section along a radial direction of the combustion lining (11) gradually decreases from upstream in the circumferential direction to downstream in the circumferential direction. [3] Combustion chamber (10) according to claim 2, wherein the screw passage (23) is shaped such that a central position of a flow passage cross-section moves downstream along the radial direction of the combustion lining (11) in the axial direction of the combustion lining (11), while the screw passage (23) extends from upstream in the circumferential direction to downstream in the circumferential direction. [4] Internal combustion engines (10), including: a combustion lining (11); a premixing tube (20) arranged upstream of the combustion lining (11) in an axial direction of the combustion lining (11) and containing a screw passage (23) extending in a circumferential direction of the combustion lining (11), and an axial passage (25) extending in the axial direction of the combustion lining (11) to connect the screw passage (23) to an interior of the combustion lining (11); and a first fuel nozzle (31) which is arranged upstream of the screw passage (23) in the circumferential direction and has an injection opening (31a) for injecting fuel into the screw passage (23), wherein the injection port (31a) is arranged at a position which overlaps in the axial direction with a region in which the screw passage (23) exists, wherein the premixing tube (20) has a tangential passage (21) which is connected to an end section (11a, 11b, 23a, 25a, 25b, 41a) of the screw passage (23) on a circumferentially upstream side and extends in a tangential direction of a screw at the end section (11a, 11b, 23a, 25a, 25b, 41a), wherein the injection port (31a) is arranged upstream of the tangential passage (21), and wherein the screw passage (23) is shaped such that a central position of a flow passage cross-section moves downstream along the radial direction of the combustion lining (11) in the axial direction of the combustion lining (11), while the screw passage (23) extends from upstream in the circumferential direction to downstream in the circumferential direction. [5] Combustion chamber (10) according to claim 4, wherein the screw passage (23) is shaped such that a region of a flow passage cross-section along a radial direction of the combustion lining (11) gradually decreases from upstream in the circumferential direction to downstream in the circumferential direction. [6] Combustion engine (10) according to claim 4 or 5, wherein the housing (45, 70) has an air inlet section (71) for supplying air into the housing (45, 70) and a side wall section (73) which covers the premixing tube (20) from a radially outer side of the combustion lining (11) and has the air inlet section (71). [7] Internal combustion engine (10) according to claim 1, 2, 3, or 6, wherein the housing (45, 70) has an air inlet section (71) for supplying air into the housing (45, 70) and a side wall section (73) which covers the premixing tube (20) from a radially outer side of the combustion lining (11) and has the air inlet section (71), and wherein an inlet end of the premixing tube (20) is arranged in a region (11r, 24a, 70a, 70b) inside the housing (45, 70) on a side opposite an axis of the combustion lining (11) from a region (11r, 24a, 70a, 70b) in which the air inlet section (71) is positioned. [8] Internal combustion engine (10) according to claim 7, wherein the injection opening (31a) is arranged in the region (11r, 24a, 70a, 70b) on the opposite side. [9] Combustion engine (10) according to one of claims 1 to 8, wherein the injection opening (31a) is arranged at a distance from an end section (11a, 11b, 23a, 25a, 25b, 41a) of the screw passage (23) on an upstream side in the circumferential direction along a tangential direction of a screw at the end section (11a, 11b, 23a, 25a, 25b, 41a), such that the distance is within twice the diameter of the screw passage (23) at the end section (11a, 11b, 23a, 25a, 25b, 41a). [10] Internal combustion engine (10) according to any one of claims 1 to 9, wherein the axial passage (25) is ring-shaped along the circumferential direction, and wherein the combustion chamber (10) further comprises a spark plug (41) for igniting an air-fuel mixture from the fuel and the air supplied from the premixing tube (20) into the combustion lining (11), wherein the spark plug (41) is arranged in a central region (24a) which is annularly surrounded by the axial passage (25) from a radially outer side. [11] Combustion engine (10) according to claim 10, further comprising a cooling air duct through which cooling air flows to cool the spark plug (41), wherein the cooling air duct is arranged on one side of the spark plug (41) in the central region (24a). [12] Combustion engine (10) according to claim 10 or 11, further comprising a second fuel nozzle (32, 35) arranged in the central region (24a) to supply the fuel to the combustion lining (11). [13] Combustion engine (10) according to any one of claims 1 to 12, further comprising an outer cylinder part (80) which faces an outer circumferential surface (11c, 51b) of the combustion lining (11) at a distance from the outer circumferential surface (11c, 51b), wherein the outer cylinder part (80) has a first region (81) which faces the outer circumferential surface (11c, 51b) at a first distance, and a second region (82) which is arranged downstream of the first region (81) and faces the outer circumferential surface (11c, 51b) at a second distance which is smaller than the first distance. [14] Internal combustion engine (10) according to claim 13, wherein the outer cylindrical part (80) has a third region (83) which lies downstream of the second region (82) and faces the outer circumferential surface (11c, 51b), with a third distance which is greater than the second distance, and wherein the combustion lining (11) has a plurality of opening sections (13, 23b, 75a) formed in a region (11r, 24a, 70a, 70b) facing the third region (83). [15] Internal combustion engine (10) according to any one of claims 1 to 14, wherein the combustion lining (11) has a plurality of cutout sections extending in the axial direction from an axially downstream end section (11a, 11b, 23a, 25a, 25b, 41a) of the combustion lining (11) and arranged at intervals along the circumferential direction, and wherein the combustion chamber (10) further comprises a retaining part (90) which pushes the end section (11a, 11b, 23a, 25a, 25b, 41a) of the combustion lining (11) away from a radially outer or inner side of the combustion lining (11) in order to hold the end section (11a, 11b, 23a, 25a, 25b, 41a). [16] Combustion engine (10) according to any one of claims 1 to 15, further comprising a flow guide (51) which is arranged upstream of the screw passage (23) in the circumferential direction to straighten air flowing into the screw passage (23). [17] Internal combustion engine (10) according to any one of claims 1 to 16, wherein the axial passage (25) has a cylindrical outer wall section (26) arranged on a radially outer side of the combustion lining (11), and a cylindrical inner wall section (27) arranged on a radially inner side at a distance in a radial direction of the combustion lining (11) from the outer wall section (26), and wherein at least the outer wall section of the outer wall section (26) and the inner wall section (27) are shaped such that a dimension in the radial direction gradually increases, while the outer wall section extends downstream in the axial direction in a downstream region (11r, 24a, 70a, 70b) of the axial passage (25). [18] Gas turbine, comprising: the combustion engine (10) according to any one of claims 1 to 17; a compressor for generating compressed air; and a turbine configured to be set in rotation by a combustion gas from the combustion engine (10).

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