2189 results about "Centrifugal compressor" patented technology

A high speed centrifugal compressor for compressing fluids includes a permanent magnet synchronous motor (PMSM) having a hollow shaft, the being supported on its ends by ball bearing comprising supports. A permanent magnet core is embedded inside the shaft. A stator with a winding is located radially outward of the shaft. The PMSM includes a rotor including at least one impeller secured to the shaft or integrated with the shaft as a single piece. The rotor is a high rigidity rotor providing a bending mode speed of at least 100,000 RPM which advantageously permits implementation of relatively low-cost ball bearing comprising supports.

This invention provides a small, high efficiency, oil free motor driven compressor/blower suitable for providing pressurized, contamination-free gas and or air to transportation, industrial and aerospace fuel cell systems or other contaminant-intolerant applications. The motor driven compressor/blower rotor assembly is supported by foil air bearings and rotates at high speed by using a high frequency drive. The impeller is a centrifugal type design. The MDC can be easily integrated into the air management system of a fuel cell.

The present invention relates to a refrigeration or air-conditioning apparatus which utilizes a vapor compression refrigeration system having a refrigerant circulating therethrough that comprises a compressor powered by an engine exhaust gas driven turbine. A mini centrifugal compressor may advantageously be used with such an apparatus, thus allowing the use of low GWP refrigerants. The present invention further relates to methods for powering a compressor, such as a mini-centrifugal compressor, in a refrigeration or air-conditioning apparatus, and methods for controlling compressor surge, impeller speed and cooling capacity.

A high efficiency, low maintenance single stage or multi-stage centrifugal compressor assembly for large cooling installations. The assembly is highly efficient by virtue of a variable frequency drive (VFD) that drives a permanent magnet motor and matches compressor speed with compressor load, a direct drive impeller that eliminates gearing losses, and magnetic bearings that reduce frictional losses. The back-emf produced by the motor provides an intermediate power source for the magnetic bearings in the event of a loss of electrical power. A cooling system provides direct cooling of the rotor with gas refrigerant, and cooling of the stator with liquid refrigerant. Modular construction allows the compressor to be retrofit with upgrades. An inlet guide vane system operates without need for oil lubrication. The use of light metal castings and elimination of gearing reduces the weight to one-third or less of comparably powered conventional units.

This compressor unit comprises a motor (34) and at least one compressor (44) comprising a driven shaft (54) driven by the rotor of the motor and bladed wheels fitted on the driven shaft (54), the assembly composed of the motor and the compressor being installed in a common casing (55) leak tight to the gas manipulated by the compressor unit. The rotor and the driven shaft are connected through a flexible coupling (72) placed in the casing.

The present invention relates to a cooling apparatus comprising a refrigeration or air-conditioning apparatus. In particular the present invention relates to refrigeration or air-conditioning apparatus utilizing a mini-centrifugal compressor with rotational power provided by a ratioed gear drive assembly coupled to an internal combustion engine.

A seal for a rotary compressor comprises a casing, at least one assembly having a rotating seal face ring which rotates as one with a sleeve intended to be mounted on a shaft of the compressor and of a stationary seal face ring mounted on the casing, the seal face rings being urged to press against one another via their rubbing face. The seal design further incorporates fluid circulation for heating leaks of compressible fluid conveyed by the compressor that occur between the seal face rings, this fluid circulation being formed in the casing and extending at least partially downstream of the seal face rings with respect to the direction of flow of the fluid stream.

A motor-driven centrifugal compressor includes a journal air bearing having a bump foil and a top foil for restraining a bearing shaft in a resting state and forming an air layer between the top foil and the bearing shaft in a rotating state. The top foil and the bump foil are fixed to an inner circumferential surface of a ring member, which is fixed to an inner circumferential surface of a first stationary holding member of the ring member. The first stationary holding member has a coolant water channel defined therein. The bearing shaft, the air layer, the top foil, the bump foil, and the coolant water channel are arranged in the order named along a normal direction.

A high-pressure multi-stage centrifugal compressor is provided containing at least three compressor elements which are arranged in series as compressor stages, and at least two electric motors to drive these compressor elements. At least one compressor element forms a low-pressure stage which is driven by an electric motor. At least two compressor elements form high-pressure stages, and are arranged in series and driven by one and the same second electric motor.

The present invention relates to compositions for use in refrigeration and air-conditioning systems comprising at least one bromofluoro-olefin. The present invention further relates to refrigerant and heat transfer fluid compositions comprising a flammable refrigerant and a bromofluoro-olefin. The present invention further relates to compositions for use in refrigeration apparatus and air-conditioning apparatus employing a centrifugal compressor comprising at least one bromofluoro-olefin. Further, the present invention relates to the utility of the present refrigerant and heat transfer fluid compositions in processes for producing heat and cooling, methods for reducing flammability of a refrigerant, methods for lowering GWP of a refrigerant, methods for replacing refrigerants and other uses.

A centrifugal compressor unit includes a driving means for rotatably driving a rotor, and at least one compressor including a statoric body and an arrangement of blade wheels mounted on a shaft which is rotatably driven by the rotor in the statoric body. The group formed by the motor and/or each compressor being mounted in a common housing is sealed from the gas used by the compressor. The compressor unit also includes an arrangement of active bearings for axially and radially guiding the rotor and the driven shaft, and a means for cooling the driving means and the guiding bearings by withdrawing the gas used by the compressor at the outlet of a first compression stage. The cooling means includes a set of internal conduits for supplying the driving means and the bearings with cooling gas. The cooling gas flow in the motor and the cooling gas flow in the bearing is separated and then converge upstream of the first compression stage.

Disclosed herein are hydrofluorocarbon refrigerant or heat transfer fluid compositions that are useful in refrigerain or air conditioning apparatus or as heat transfer fluids. The compositions of the present invention are also useful in centrifugal compressor apparatus that employ two-stage compressors or single slab.single pass heat exchangers.

A stability control algorithm is provided for a centrifugal compressor. The stability control algorithm is used to control a variable geometry diffuser and a hot gas bypass valve (when provided) in response to the detection of compressor instabilities. The stability control algorithm can adjust the position of a diffuser ring in the variable geometry diffuser in response to the detection of a surge condition or a stall condition. In addition, the diffuser ring in the variable geometry diffuser can be adjusted to determine an optimal position of the diffuser ring. The stability control algorithm can also be used to open a hot gas bypass valve in response to the detection of continued surge conditions.

A high efficiency, low maintenance single stage or multi-stage centrifugal compressor assembly for large cooling installations. A cooling system provides direct, two-phase cooling of the rotor by combining gas refrigerant from the evaporator section with liquid refrigerant from the condenser section to affect a liquid/vapor refrigerant mixture. Cooling of the stator with liquid refrigerant may be provided by a similar technique. A noise suppression system is provided by injecting liquid refrigerant spray at points between the impeller and the condenser section. The liquid refrigerant may be sourced from high pressure liquid refrigerant from the condenser section.

Internal combustion engine with a centrifugal compressor or positive displacement air supercharger incorporating a high speed electric motor on the drive shaft for the purpose of acceleration and generation of pressurized air at low engine speeds and incorporation of one-way and/or magnetic clutches for efficient operation.

A system and method is provided for detecting and controlling rotating stall in the diffuser region of a centrifugal compressor. The process begins with the detection or sensing of acoustic energy associated with the onset of rotating stall. A pressure transducer is placed in the gas flow path downstream of the impeller, preferably in the compressor discharge passage or the diffuser, to measure the sound or acoustic pressure phenomenon. Next, the signal from the pressure transducer is processed either using analog or digital techniques to determine the presence of rotating stall. Rotating stall is detected by comparing the detected energy amount, which detected energy amount is based on the measured acoustic pressure, with a predetermined threshold amount corresponding to the presence of rotating stall. Finally, an appropriate corrective action is taken to change the operation of the centrifugal compressor in response to the detection of rotating stall.

On a suction surface side of a blade in an impeller, a convex portion is formed to assume a curved line from a front edge portion to a throat portion substantially in the middle in a radial direction, and this convex portion is formed to be flat assuming a curved line from the throat portion toward a rear edge portion, whereby this convex portion is formed in a position where a relative inlet velocity of fluid into the impeller is Mach number Ma≅1.

The invention relates to a process for cooling or heating a fluid or a body by means of a vapour compression circuit comprising a centrifugal compressor and containing a heat-transfer fluid, the heat-transfer fluid comprising at least two compounds selected from 2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene, 1,1,1,2-tetrafluoropropene, 1,1-difluoroethane and 3,3,3-trifluoropropene, in which: the ratio of the Mach number of the centrifugal compressor to the Mach number which the centrifugal compressor has under the same operating conditions if the heat-transfer fluid is replaced with 1,1,1,2-tetrafluoroethane in the vapour compression circuit is greater than or equal to 0.97 and less than or equal to 1.03; the compression ratio of the centrifugal compressor is less than or equal to the compression ratio which the centrifugal compressor has under the same operating conditions if the heat-transfer fluid is replaced with 1,1,12-tetrafluorethane in the vapour compression circuit. The invention also relates to equipment suitable for implementing this cooling or heating process, and also to a process for converting existing equipment.

An object is to position a plurality of guide vanes for generating swirl flow at a housing inner circumferential side in front of an impeller wheel to improve a surge margin and to restrict the decrease in a choke flow rate, thereby increasing an operation range of a compressor. A compressor 19 includes a compressor housing 15, an impeller wheel 7 which compresses intake gas flowing in from an intake-air inlet 23, a swirl-flow generating part including a plurality of guide vanes 55 disposed circumferentially along an inner circumferential wall of the intake-air channel 21 between the intake-air inlet 23 and the impeller wheel 7 and which swirls the intake gas from the intake-air inlet 23 around the rotational axis, and a central intake-air flow path 59 formed inside the guide vanes 55 to allow intake gas to flow to the impeller wheel 7 without passing through the guide vanes 55.