# US 10,767,508 B2 · Gas expander > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,767,508 B2 - Document ID: US10767508B2 - Status: Granted - Kind: B2 - Application number: 15/771,060 - Filed: 2016-02-09 - Published: 2018-11-08 - Granted: 2020-09-08 - Earliest claimed: 2016-02-09 - Assignees: Mitsubishi Heavy Industries Compressor Corporation - Applicants: Mitsubishi Heavy Industries Compressor Corporation - Inventors: Naoto Yonemura; Daisuke Hirata; Hirotaka Higashimori - Web page: https://patentgrep.com/patent/US10767508B2 ## CPC - F01D 25/04: Antivibration arrangements - F01D 1/08: having inward flow - F01D 9/02: Nozzles; Nozzle boxes; Stator blades; Guide conduits {, e.g. individual nozzles (nozzle boxes F01D9/047)} - F01D 25/30: Exhaust heads, chambers, or the like - F02C 1/04: the working fluid being heated indirectly {(in a fluidised-bed combustor F02C3/205)} - F02K 1/40: Nozzles having means for dividing the jet into a plurality of partial jets or having an elongated cross-section outlet - F05D 2220/30: in turbines - F05D 2240/12: Fluid guiding means, e.g. vanes - F05D 2240/128: Nozzles - F05D 2240/24: for turbines - F05D 2260/96: Preventing, counteracting or reducing vibration or noise - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract A gas expander includes: a casing where a swirl chamber for a gas to be expanded is formed; a turbine wheel that is housed in the casing and rotationally driven by the expanded gas; a diffuser that is mounted to the casing in a direction of a rotating shaft of the turbine wheel and includes a flow path for the expanded gas to flow in the direction of the rotating shaft; a swirl stopper that is disposed in the diffuser, faces a downstream front end surface of a boss of the turbine wheel that faces the flow path, and includes a closed swirl stopping surface that is disposed to face the downstream front end surface of the boss with a gap between the closed swirl stopping surface and the downstream front end surface; and a swirl preventing plate that circumferentially partition the flow path in the diffuser. ## Claims ### Claim 1 A gas expander comprising: a casing where a swirl chamber is formed, wherein a gas to be expanded passes through the swirl chamber; a turbine wheel that is housed in the casing and rotationally driven by the gas, wherein the gas that rotationally drives the turbine wheel has passed through the swirl chamber and expanded; a diffuser that: is mounted to the casing in a direction of a rotating shaft of the turbine wheel, and includes a flow path where the gas, having passed through the turbine wheel, flows in the direction of the rotating shaft, a swirl stopper that: is disposed in the diffuser, faces a downstream front end surface of a boss of the turbine wheel that faces the flow path, and includes a closed swirl stopping surface that is disposed to face the downstream front end surface of the boss with a gap between the closed swirl stopping surface and the downstream front end surface; and a swirl preventing plate that circumferentially partitions the flow path, wherein L31≥D10≥0.75 is satisfied, where D10 is a diameter of an inlet of the flow path and L31 is a distance from the inlet to an end on the upstream side of the swirl preventing plate. ### Claim 2 (depends on 1) The gas expander according to claim 1, wherein: the swirl preventing plate is provided on a downstream side of the flow path, the flow path includes: a pressure recovery region on an upstream side, and a swirl flow stopping region on the downstream side continuous with the pressure recovery region. ### Claim 3 (depends on 2) The gas expander according to claim 2, wherein L31≥D10×0.75 is satisfied, where D10 is a diameter of an inlet of the flow path and L31 is a distance from the inlet to an end on the upstream side of the swirl preventing plate. ### Claim 4 (depends on 2) The gas expander according to claim 2, wherein L31≥D10×1.2 is satisfied, where D10 is a diameter of an inlet of the flow path and L31 is a distance from the inlet to an end on the upstream side of the swirl preventing plate. ### Claim 5 (depends on 2) The gas expander according to claim 2, wherein: in the diffuser, a flow path area increases from the upstream side toward the downstream side, the swirl preventing plate is disposed so that the end on the upstream side of the swirl preventing plate is away from the inlet, and A1×1.6≤A2 is satisfied, where A1 is the flow path area at the inlet of the flow path and A2 is the flow path area at the end on the upstream side of the swirl preventing plate. ### Claim 6 (depends on 2) The gas expander according to claim 2, wherein L35≥D10×0.45 is satisfied, where L35 is an axial dimension of the swirl preventing plate and D10 is a diameter of the inlet of the flow path. ### Claim 7 (depends on 1) The gas expander according to claim 1, wherein L31≥D10×1.2 is satisfied, where D10 is a diameter of an inlet of the flow path and L31 is a distance from the inlet to an end on the upstream side of the swirl preventing plate. ### Claim 8 (depends on 1) The gas expander according to claim 1, wherein: in the diffuser, a flow path area increases from the upstream side toward the downstream side, the swirl preventing plate is disposed so that the end on the upstream side of the swirl preventing plate is away from the inlet, and A1×1.6≤A2 is satisfied, where A1 is the flow path area at the inlet of the flow path and A2 is the flow path area at the end on the upstream side of the swirl preventing plate. ### Claim 9 (depends on 1) The gas expander according to claim 1, wherein: the gas expander includes a plurality of swirl preventing plates, and the plurality of swirl preventing plates radially partition the flow path. ### Claim 10 (depends on 1) The gas expander according to claim 1, wherein: the swirl stopper includes a cylindrical member disposed coaxially with the rotating shaft of the turbine wheel, and D32≥D13×0.95 is satisfied, where D32 is a diameter of the closed swirl stopping surface of the swirl stopper and D13 is a diameter of the downstream front end surface of the boss of the turbine wheel. ### Claim 11 (depends on 10) The gas expander according to claim 10, wherein D13×1.2≥D32≥D13×0.95 is satisfied. ### Claim 12 (depends on 1) The gas expander according to claim 1, wherein: the swirl stopper is secured to the swirl preventing plate and the swirl preventing plate is secured to the diffuser, and the swirl stopper is mounted to a predetermined position of the diffuser via the swirl preventing plate. ### Claim 13 (depends on 12) The gas expander according to claim 12, wherein: the gas expander includes a plurality of swirl preventing plates, and the plurality of the swirl preventing plates radially partition the flow path in the diffuser around the swirl stopper. ### Claim 14 (depends on 1) The gas expander according to claim 1, wherein: the gas expander further includes a plurality of swirl preventing plates, and the plurality of swirl preventing plates radially partition the flow path. ### Claim 15 A gas expander comprising: a casing where a swirl chamber is formed, wherein a gas to be expanded passes through the swirl chamber; a turbine wheel that is housed in the casing and rotationally driven by the gas, wherein the gas that rotationally drives the turbine wheel has passed through the swirl chamber and expanded; a diffuser that: is mounted to the casing in a direction of a rotating shaft of the turbine wheel, and includes a flow path where the gas, having passed through the turbine wheel, flows in the direction of the rotating shaft, a swirl stopper that: is disposed in the diffuser, faces a downstream front end surface of a boss of the turbine wheel that faces the flow path, and includes a closed swirl stopping surface that is disposed to face the downstream front end surface of the boss with a gap between the closed swirl stopping surface and the downstream front end surface; and a swirl preventing plate that circumferentially partitions the flow path, wherein L35≥D10×0.45 is satisfied, where L35 is an axial dimension of the swirl preventing plate and D10 is a diameter of the inlet of the flow path. ### Claim 16 A gas expander comprising: a casing where a swirl chamber is formed, wherein a gas to be expanded passes through the swirl chamber; a turbine wheel that is housed in the casing and rotationally driven by the gas, wherein the gas that rotationally drives the turbine wheel has passed through the swirl chamber and expanded; a diffuser that: is mounted to the casing in a direction of a rotating shaft of the turbine wheel, and includes a flow path where the gas, having passed through the turbine wheel, flows in the direction of the rotating shaft, a swirl stopper that: is disposed in the diffuser, faces a downstream front end surface of a boss of the turbine wheel that faces the flow path, and includes a closed swirl stopping surface that is disposed to face the downstream front end surface of the boss with a gap between the closed swirl stopping surface and the downstream front end surface; and a swirl preventing plate that circumferentially partitions the flow path, wherein in the swirl stopper, the closed swirl stopping surface has a protruding peripheral edge and an inner side recessed from the peripheral edge, and the swirl stopper covers the downstream front end surface of the boss and an outer peripheral surface of the turbine wheel continuous with the downstream front end surface of the boss.