Abstract: In order to improve a machine for depressurizing or compressing substantially gaseous media, comprising a machine casing and at least one screw rotor, which is arranged in a screw rotor bore in the machine casing, extends between a low-pressure side and a high-pressure side of the screw rotor bore, cooperates with the substantially gaseous medium and is mounted on both sides in the machine casing by means of a respective bearing set, and a motor/generator unit that is coupled or couplable to the at least one screw rotor, it is proposed that the at least one screw rotor should be provided with at least one axial support bearing that axially supports the at least one screw rotor such that a high-pressure end face of the at least one screw rotor is guided, without making contact, to an end wall, which faces this end face, of the machine casing that receives the at least one screw rotor.

Abstract: A scroll compressor includes two scroll bodies each having a scroll rib. The scroll ribs engage each other to form at least one compression chamber. The scroll compressor further comprises a drive shaft for driving a moveable scroll body of the two scroll bodies. The moveable scroll body includes a base plate which has two opposing sides. On a first side of the two opposing sides, the scroll rib is arranged, and on a second side of the two opposing sides a hub is arranged. The hub has a receiving portion for a drive section of the drive shaft. The moveable scroll body has at least one passage from an interior of the receiving portion to a hub environment located around the hub at the second side of the two opposing sides.

Abstract: In order to improve a refrigerant compressor of the type mentioned in the introduction such that it is ensured that, even in the event of a tilt along a longitudinal direction of the refrigerant compressor unit relative to a horizontal course of the longitudinal direction, lubricant can reliably be drawn off by suction out of the lubricant sump, in order to prevent excessive accumulation of lubricant in the lubricant sump, it is proposed that there should be provided on the bottom side of the motor compartment a receiving point that takes a form such that the receiving point supplies lubricant from the lubricant sump to the suction-removal unit.

Abstract: In order to improve a method for selecting a frequency converter for a refrigerant compressor unit comprising a refrigerant compressor and an electric drive motor in such a way that the frequency converter is optimised for the application in question, it is proposed that a working state suitable for the operation of the refrigerant compressor unit is selected in an application field of an application diagram of the refrigerant compressor, that an operating frequency is selected for this selected working state, and that, on the basis of drive data, a working state operating current value corresponding to the selected working state and the selected operating frequency is ascertained for the operation of the refrigerant compressor unit.

Abstract: In order to increase the efficiency, in respect of the quantity of refrigerant to be compressed, of a reciprocating piston compressor for refrigerant, comprising a compressor housing having at least one compressor stage that has at least one cylinder unit, wherein a piston is movably arranged in the cylinder unit, a cylinder drive that is arranged in the compressor housing, for the at least one piston, a valve plate that closes off a cylinder chamber and is provided with at least one suction valve which, for its part, has a suction opening, arranged in the valve plate and closable by a suction vane, and has at least one outlet valve with an outlet opening, wherein the at least one suction valve and the at least one outlet valve are associated with the respective cylinder chamber, and a cylinder head that is arranged on an opposite side of the valve plate to the cylinder chamber, it is proposed that the valve plate should have, on its side facing the cylinder chamber, a recess, which is arranged inside an exte

Abstract: A refrigeration system, in particular a transport refrigeration system, comprising: a refrigerant circuit, which in particular works using CO2 as the refrigerant and in which there is guided a total mass flow of the refrigerant; a high-pressure-side heat exchanger arranged in the refrigerant circuit and cooling refrigerant compressed to a high pressure; at least one cooling stage which expands the principal mass flow from the intermediate-pressure collector to a low pressure in at least one cooling expansion member and in so doing makes refrigeration capacity available at a low-pressure-side heat exchanger; and a refrigerant compressor unit which compresses the principal mass flow from a low pressure to a high pressure, wherein the refrigerant compressor unit has a first compressor stage for compressing, to a medium pressure, the refrigerant of the principal mass flow supplied at low pressure, and a second compressor stage for compressing, to a high pressure, the refrigerant of the principal mass flow that ha

Abstract: In order to improve a method for selecting a frequency converter for a refrigerant compressor unit comprising a refrigerant compressor and an electric drive motor in such a way that the frequency converter is optimised for the application in question, it is proposed that a working state suitable for the operation of the refrigerant compressor unit is selected in an application field of an application diagram of the refrigerant compressor, that an operating frequency is selected for this selected working state, and that, on the basis of drive data, a working state operating current value corresponding to the selected working state and the selected operating frequency is ascertained for the operation of the refrigerant compressor unit.

Abstract: In order to improve a method for operating status determination of a refrigerant compressor/expander comprising a compressor unit and a drive unit such that information on the operating status of a refrigerant compressor/expander which is as reliable as possible can be obtained, it is proposed that, for at least one bearing of the refrigerant compressor/expander, a load value resulting from an operation of said refrigerant compressor/expander and a speed value are determined and in that, on the basis of the speed value and the load value and also at least one operating parameter, there is determined for the at least one bearing an operating prediction value for a future maintenance-free operation of the refrigerant compressor/expander.

Abstract: A cold generator incorporates a heat exchanger unit integrating a heat-emitting heat exchanger and a heat-absorbing heat exchanger. The heat exchanger unit has a flow path layer stack built up in a stacked construction. In order to form the heat-emitting heat exchanger in the flow path layer stack, at least one heat-emitting refrigerant flow path and at least one heat-absorbing second heat transport flow path are provided. A second heat transport medium guided in a second heat transport circuit is arranged to flow through the second heat transport flow path. At least one heat-absorbing refrigerant flow path and at least one heat-emitting first heat transport flow path are provided in order to form the heat-absorbing heat exchanger in the flow path layer stack with a first heat transport medium guided in a first heat transport circuit that is arranged to flow through the first heat transport flow path.

Abstract: A plurality of scroll compressors with different fixed volume indexes are connected in fluid parallel circuit and configured to selectively operate to maximize isentropic efficiency at different condensing temperatures. Different quantities of scroll compressors of different volume indexes may be selected based upon typical climate or geographic location environmental conditions to attempt to maximize efficiency. A controller may selectively operate different combinations of the compressors of different volume indexes bases up load demands and condensing temperature conditions, which may be determined in a variety of ways.

Abstract: A method of manufacturing a two-piece counterweight for a scroll compressor is provided. The method includes molding an outer plate, and molding a base having a first opening configured to receive a scroll compressor drive shaft having a longitudinal axis. The method further includes configuring the base for assembly and attachment to the drive shaft. The method also includes attaching the outer plate to the base such that the outer plate is axially offset from the base. In a particular embodiment of this method, the base and outer plate are molded from powdered metal. In certain embodiments, the base and outer plate include one or more openings aligned to permit attachment by inserting a mechanical fastener through the aligned openings. In alternate embodiments, the base and outer plate are attached via brazing or welding.

Abstract: A device is provided comprising an expansion machine for generating mechanical energy by expanding vapor of a working medium; a generator connected to a shaft of the expansion machine and used for generating electric energy from mechanical energy of the expansion machine; wherein the expansion machine and the generator form a structural unit with an exhaust vapor chamber between the expansion machine and the generator, and wherein, when the expansion machine is in operation, working medium expanded into the exhaust vapor chamber contacts the generator; and means for feeding, in particular injecting, a liquid working medium into the exhaust vapor chamber. Also provided is an ORC device comprising the device and a method for operating the device.

Abstract: A suction fitting coupled to a scroll compressor that has an outer housing with an inside diameter and a suction port defined in a wall of the outer housing. A suction duct is disposed inside the outer housing at a spaced distance from the wall of the outer housing. The suction duct defines an entrance port aligned with the suction port. The suction fitting includes a first member being generally cylindrical, and a second member being generally cylindrical. The second member is disposed inside the first member with a portion of the second member extending into the outer housing through the suction port, spanning the spaced distance to the suction duct, and coupling with the entrance port of the suction duct. Neither the first member nor the second member includes a suction screen for filtering out solid contaminants in a flow of refrigerant.

Abstract: A refrigerant compressor group for a refrigeration system, comprising at least two piston compressors that operate in parallel between a common low-pressure connector and a common high-pressure connector, wherein, for the purpose of adjusting it to different requirements, it is provided, in a refrigerant compressor group, for a variable overall mass flow throughput in the refrigerant compressor group to be adjustable in that, in the case of at least one of the piston compressors, its mass flow throughput is adjustable by speed selection with the aid of a frequency converter for the electric motor, and in that, in the case of at least one of the piston compressors, its mass flow throughput is adjustable by cylinder selection, and in that an operating condition controller for the refrigerant compressor group is provided which, on the basis of a performance request signal of the refrigeration system that is transmitted to the operating condition controller, controls the overall mass flow throughput by open or cl

Abstract: A refrigerant compressor unit, including a compressor housing and at least one compressor element that is arranged in the compressor housing, is movable by bearing and drive parts, and operates in at least one compressor chamber, at least one lubricant supply point arranged in the compressor housing for at least one of the bearing and drive parts and/or compressor element, and a lubricant supply line to the at least one lubricant supply point, wherein the lubricant supply line has a lubricant storage chamber through which lubricant flows and in which a lubricant presence sensor is arranged for detecting the presence of lubricant in the lubricant storage chamber.

Abstract: A refrigerant compressor for a refrigeration system comprises a common housing, a compressor unit arranged in the common housing, a mechanical compressor drive unit for the compressor unit, arranged in a drive chamber, a lubricant bath forming in the drive chamber, an intake duct that extends in a manner separated from the drive chamber and through which the compressor unit draws in by suction refrigerant that is to be compressed. The intake duct and the drive chamber are connected by a gas equaliser duct, which allows a permanent equalisation of gas, and which has on one side an opening on the drive chamber side and on the other an opening on the intake side, and of which the duct length between the openings corresponds to at least twice an equivalent duct diameter, in particular a smallest equivalent duct diameter, of the gas equaliser duct.

Abstract: A compressor unit including a screw compressor having a compressor housing that has a screw rotor chamber arranged in the compressor housing, two screw rotors that are arranged in the screw rotor chamber and are mounted on the compressor housing to be rotatable about a respective screw rotor axis, and at least one control slider, which is arranged in a slider channel of the compressor housing, is adjacent to both screw rotors and is movable in a direction of displacement parallel to the screw rotor axes and takes a form such that it affects the final volume and/or the initial volume, wherein there is provided on the screw compressor a compressor operational control unit that takes a form such that it performs a compressor operating function that assists at least one operation of the compressor unit.

Abstract: A cooling circuit comprises a refrigerant compressor incorporating a suction port and a pressure chamber incorporating a pressure port, a condenser arranged downstream of the pressure port, a fluid collecting chamber in which a reservoir of refrigerant is formed, an evaporator which is located between the condenser and the suction port, a feed unit which is connected at one side to the refrigerant reservoir and to the pressure chamber at the other side and which serves for supplying refrigerant from the refrigerant reservoir to the pressure chamber which incorporates a pumping unit for the refrigerant. It is proposed that in order improve this cooling circuit, the pumping unit comprise a pressure-tight closed housing which is provided with only one inlet and one outlet as access points and a pumping element which is movable for pumping the refrigerant be arranged in the pumping chamber thereof.

Abstract: Refrigerant compressor for refrigeration systems, comprising an electric motor, at least two cylinder banks and a mechanical performance control unit for activating and deactivating at least one of the cylinder banks in order to activate or deactivate its refrigerant output, wherein, for the purpose of operation in partial performance conditions, the refrigerant compressor is operable in at least two different operating modes, of which each provides an activation or deactivation of the cylinder banks that is different from the other operating modes, wherein associated with the refrigerant compressor is a frequency converter for controlling the speed of the electric motor, wherein associated with the refrigerant compressor is an operating condition controller that, in accordance with a performance request signal supplied to it for operation of the refrigerant compressor in the partial performance condition corresponding to this performance request signal, operates the refrigerant compressor in an operating mod

Abstract: A compressor unit including a screw compressor having a compressor housing that has a screw rotor chamber arranged in the compressor housing, two screw rotors that are arranged in the screw rotor chamber and are mounted on the compressor housing to be rotatable about a respective screw rotor axis, and at least one control slider, which is arranged in a slider channel of the compressor housing, is adjacent to both screw rotors and is movable in a direction of displacement parallel to the screw rotor axes and takes a form such that it affects the final volume and/or the initial volume, wherein there is provided on the screw compressor a compressor operational control unit that takes a form such that it performs a compressor operating function that assists at least one operation of the compressor unit.