Abstract: On an energy guiding chain for guiding hoses, cables or the like between two connecting points moving relative to each other, with several chain links connected to each other in articulated fashion, each of which displays two side straps and cross-pieces connecting them, where the chain consists of a strand that can be connected to one of the connecting points, and a strand that can be connected to the other connecting point, these transitioning into each other via a deflection zone, and where at least some of the chain links display runners covering the upper side of the side straps, it is envisaged that the runners be mounted on the cross-pieces at a distance from the side straps in order to reduce the assembly effort.

Abstract: A gas turbine system is provided. The system includes a gas turbine engine including at least one combustor can, at least one of a combustor dynamics pressure sensor and flame sensor coupled to at least one of the combustor cans, the sensor configured to monitor combustion in each respective can and transmit a signal indicative of combustion in each respective can, and at least one control system configured to receive the signal from said at least one sensor. The control system is programmed to filter the combustion signal to determine the presence of a lean blowout (LBO) precursor, determine a probability of LBO from the filtered signal, and control the gas turbine system to facilitate reducing the probability of LBO.

Abstract: In a method for generating energy in an energy generating installation (10) having a gas turbine (12), in a first step, an oxygen-containing gas is compressed in a compressor (13, 14) of the gas turbine (12), in a second step the compressed gas is supplied, with the addition of fuel, for combustion in a combustion chamber (15), in a third step the hot flue gas from the combustion chamber (15) is expanded in a turbine (16) of the gas turbine (12) so as to perform work, and, in a fourth step, a branched-off part stream of the expanded flue gas is recirculated into a part of the gas turbine (12) lying upstream of the combustion chamber (15) and is compressed. A reduction in the CO2 emission, along with minimal losses of efficiency, is achieved in that carbon dioxide (CO2) is separated from the circulating gas in a CO2 separator (19), and in that measures are taken to compensate for the efficiency losses in the gas turbine cyclic process which are associated with the CO2 separation.

Abstract: A steam turbine (10) with heating steam extraction includes a plurality of turbine sections (11, 12, 15, 17, 19, 20) for the high pressure, medium pressure and low pressure ranges, which turbine sections (11, 12, 15, 17, 19, 20) are arranged in each case in a separate casing and connected by a common shaft (28), and which includes one high pressure turbine (11), at least one subsequent medium pressure turbine (15, 17), which is connected on the outlet side to two series-connected heaters (21, 24) of a district heating circuit (27), and one subsequent low pressure turbine (19, 20). Safe control of high volumetric flows of steam is achieved by providing, for heating steam extraction, two medium pressure turbines (15, 17), which operate in parallel, in separate casings, and which are connected on the outlet side in each case to one of the heaters (21, 24).

Abstract: A method for operating a gas turbine engine assembly for an aircraft that includes a wing, wherein the gas turbine engine includes a core gas turbine engine and a fan coupled to the core gas turbine engine, the gas turbine engine assembly extends upstream from the wing and includes a first cowl and a second cowl that is repositionable with respect to the first cowl. The method includes selectively positioning the second cowl in a first operational position such that airflow is channeled from the gas turbine engine across a surface of the wing to facilitate increasing lift, and selectively positioning the second cowl in a second operational position such that the airflow is channeled from the gas turbine engine to effect reverse thrust.

Abstract: A casing for a gas turbine includes a construction providing improved structural efficiency. Improved load paths and means for transmitting loads in the engine case are disclosed.

Abstract: Described herein is a method for managing regeneration of a diesel-particulate filter for a gas-exhaust system of the internal-combustion engine of a vehicle, comprising a first step of regeneration of the diesel-particulate filter during which the diesel-particulate filter is regenerated at a first regeneration rate, and a second step of regeneration of the diesel-particulate filter, during which the diesel-particulate filter is regenerated at a second regeneration rate higher than the first regeneration rate.

Abstract: Provided is a method for extending a temperature range enabling combustion of high concentration hydrocarbon, or for rapidly supplying high temperature gas to a later stage catalyst. Provided is a method for purification of exhaust gas from an internal-combustion engine comprised by: providing a temperature-raising catalyst for exhaust gas from an internal-combustion engine in an exhaust gas passage of the internal-combustion engine, along flow of said exhaust gas, at the upstream side of a purification catalyst for said exhaust gas; and introducing hydrocarbon in an amount of 1,000 to 40,000 ppm, as converted to methane, from the upstream side of the temperature-raising catalyst, wherein said temperature-raising catalyst has catalytically active components supported onto a refractory three-dimensional structure, wherein concentration of said components has a gradient such that said concentration gradually becomes lower from the inflow side toward the outflow side of said exhaust gas.

Abstract: The invention relates to a device for determination of the quantity of NOx emitted by a diesel engine (10) in a motor vehicle with common-rail fuel supply means (12) for the cylinders thereof, of the type comprising pressure recording means (32) in at least one cylinder of the engine and means (50), for determining the mass fraction of oxygen in the mixture admitted into the cylinder. Said device comprises means (58, 68), for determining a temperature of the flame front on combustion of the mixture, means (52), for determining the mass of fuel burnt in the cylinder and means (70), for calculating the quantity of NOx emitted by the combustion of the mixture in the cylinder as a function of the recorded pressure, the mass fraction of oxygen in the mixture, the temperature of the flame front and the mass of fuel burnt.

Abstract: A system for determining a NOx conversion efficiency of an exhaust gas aftertreatment component comprises means for determining an operating temperature of the exhaust gas aftertreatment component, and a control circuit. The control circuit includes a memory having instructions stored therein that are executable by the control circuit to determine a time duration that the operating temperature of the exhaust gas aftertreatment component is above a predefined temperature, and to determine the NOx conversion efficiency of the exhaust gas aftertreatment component as a function of the time duration.

Abstract: One embodiment of the present invention includes a unique technique to regulate operation of an internal combustion engine. Other embodiments include unique apparatus, devices, systems, and methods relating to internal combustion engine including exhaust aftertreatment components, apparatus, and systems.

Abstract: The invention relates to an exhaust gas regenerator (VG) comprising an exhaust gas catalyst (KAT). According to the invention, the hot-operated catalyst (KAT) is located adjacent to a diffusion membrane (MEM) that is resistant to high temperatures and is, in turn, adjacent to a regenerated gas collector (RS) that is maintained at a lower pressure (pr) than the respectively prevailing inner pressure (pk) in the catalyst, and the regenerated gas (RG) produced is supplied as a complementary fuel to a combustion device (COMB) mounted upstream of the generator (1) and/or is used otherwise in a chemico-energetic manner.

Abstract: An exhaust gas purification device senses an air-fuel ratio of exhaust gas flowing into a catalyst and performs rich purge control for supplying fuel for reduction to the catalyst. The device calculates a total reducing agent amount consumed for the reduction during the rich purge control based on the air-fuel ratio and a fresh air amount as of the rich purge control. The device sets a specified air-fuel ratio state for controlling the air-fuel ratio in a certain range enabling more precise measurement of the air-fuel ratio than in the rich purge control. The device corrects the total reducing agent amount based on a difference between an injection amount command value as of the rich purge control and the injection amount command value in the specified air-fuel ratio state and the air-fuel ratio sensed in the specified air-fuel ratio state.

Abstract: The inventive system for controlling the regeneration of depollution means (1) which is integrated into the exhaust line (2) of a motor vehicle engine (3) and is associated with a common rail fuel supply means for carrying out the depollution means regeneration strategies (6) by using the fuel post-injections into the engine cylinders, wherein said system also comprises, for each regeneration, means (7) for calculating a total time spent in different regeneration strategies and means (8) for comparing said total time with a maximum threshold value (9) in order to stop the regeneration when said threshold is exceeded.

Abstract: An exhaust gas purification apparatus for an engine includes an exhaust gas bypass connected to the engine, a muffler connected to the exhaust gas bypass, and a catalytic carrier. The muffler defines an outlet communicating with the atmosphere. The catalytic carrier defines a through-hole for receiving catalyst. The catalytic carrier is mounted in the muffler, and at the outlet of the muffler. The through-hole of the catalytic carrier communicates with the atmosphere via the outlet.

Abstract: An axle driving unit includes an axle, a hydraulic pump, a hydraulic motor having a motor shaft on which an output gear is provided to be drivingly connected to said axle, a center section having a pump mounting surface and a motor mounting surface onto which the hydraulic pump and the hydraulic motor are mounted respectively so as to be fluidly connected with each other through the center section, a housing constituted by a first housing part and a second housing part joined to each other at a joint surface, a projection integrally formed on the center section so as to be fitted to the housing, thereby fixing a position of the center section relative to the housing, and a fastener fastening the center section to the first housing part. The pump mounting surface and said motor mounting surface may be disposed perpendicular to each other said pump mounting surface and said motor mounting surface are disposed perpendicular to each other.

Abstract: A system and method for controlling shakability of a work tool. A series of input commands from a control unit to the hydraulic pump cause the hydraulic pump to cycle between a first displacement (maximum) at a first rate (maximum) and a second displacement (zero) at a second rate (less than maximum), within a predetermined frequency. Ultimately, the hydraulic pump remains in a partially upstroked position at the beginning of every cycle. Accordingly, within a small fraction of time after upstroking, the pump is capable of providing full flow to the actuators, resulting in much faster response and movement of the actuators, and therefore improved shakability of the work implement.

Abstract: A control valves for a servo steering system, having an inlet for supplying a hydraulic liquid at a first pressures and an outlet for discharging the hydraulic liquid into a region having a smaller, second pressure, especially into a pressureless reservoir. The control valve has a guide and a valve slide accommodated in the guide so as to be movable therein along an axis. The valve slide is acted upon on one side by the hydraulic liquid with the first pressure and on the opposite side by a defined supporting force. An opening structure is provided on at least one of the valve slide and guide. A cover corresponding to the opening structure is provided on the other of the guide and valve slide. A movement of the valve slide relative to the guide effects a change of a free passage area of the opening structure that is not closed off by the cover, whereby the hydraulic liquid is able to flow from the inlet, through the free passage area, to the outlet.

Abstract: A circuit inhibits power to a motor driving a pump when a vacuum condition is detected by a vacuum switch associated with the pump. The circuit is only responsive to an actuator for selectively supplying power to the motor after inhibiting power to the motor.

Abstract: The hydraulic linear actuator system of the present invention includes a pump that is configured to rotate in a single direction at a substantially constant velocity. Both the direction and flow rate of fluid through the system is controlled by adjusting the positional relationship between the stator and the rotor of the pump. This positional relationship is adjustable between a forward flow state, a non-flow state and a reverse flow state. The hydraulic linear actuator is responsive to the flow of fluid through the system so as to be displaced in a first direction by the forward flow state of the pump and in a second direction by the reverse flow state of the pump.

Abstract: A brake system includes a master cylinder that pressurizes hydraulic fluid when a brake control portion is operated; a stroke simulator that, when supplied with the hydraulic fluid pressurized by the master cylinder, produces reactive force in response to the operation of the brake control portion; and a stroke simulator disconnecting mechanism, provided in a hydraulic passage between the master cylinder and the stroke simulator, that mechanically interrupts the flow of the hydraulic fluid through the hydraulic passage when the hydraulic fluid is allowed to flow from the master cylinder to the wheel cylinder in response to the operation of the brake control portion. The stroke simulator disconnecting mechanism starts the disconnecting operation before the hydraulic fluid flows from the master cylinder to the stroke simulator.

Abstract: A turbo machine having a rotor and a stator is at least partially provided on a flow-guiding part with a catalytic coating. The catalytic coating (7, 7?) comprises at least one oxide of a transition metal or an oxide of a mixture of transition metals, wherein the transition metals are elements from groups I B, in particular Cu, Ag, Ag, II B, in particular Zn, Cd, Hg, III B, in particular Sc, Y, IV B, in particular Ti, Zr, Hf, V B, in particular V, Nb, Ta, VI B, in particular Cr, Mo, W, VII B, in particular Mn, Tc, Re and/or VIII B, in particular Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt.

Abstract: In a method of operating an internal combustion engine in the engine braking mode, wherein an adjustable cross section adjusting means is provided in the exhaust system upstream of the exhaust gas purification device and at least one of the cylinders of the internal combustion engine is provided with a throttle valve, which, in the engine braking mode, is opened so that the cylinder content is discharged directly into the exhaust system during the compression stroke of the piston and at the same time, the cross section adjusting means is moved into a blocking position, whereupon an increased pressure level is generated in the exhaust system, in the event that a characteristic variable which corresponds to the exhaust gas temperature exceeds a given limit value, the cross section adjusting means is briefly opened and subsequently again closed to avoid overheating of the exhaust system.

Abstract: A process controls filling of combustion spaces of an internal combustion engine that has at least one filling control element and one exhaust gas turbocharger whose turbine geometry can be adjusted by an electrical positioning element. In a base position of an electrical positioning element, a basic charging pressure is provided. When there is a possible or actual faulty displacement of the electrical positioning element, filling of the combustion spaces is limited by driving the filling control element. A control device controls the execution of the process.

Abstract: An object of the present invention is to provide a gas turbine combustor with improved fatigue resistance of a combustor. It is possible to intentionally reduce a stiffness of each of flanges of upper and lower walls of an end portion (outlet) of the tail pipe of the gas turbine combustor. It is possible to reduce a stiff difference between the upper and lower walls of the end portion (outlet) of the tail pipe section and side walls. Thus, it is possible to reduce compulsion deformation caused due to thermal stress generated in the end portion (outlet) of the tail pipe section on the operation of the conventional gas turbine combustor, and to reduce high stress easy to generate in the side plate. As a result, the gas turbine combustor with high fatigue resistance can be realized.

Abstract: A combustor assembly includes a metal section having an axial slot that receives a ceramic section. A clamp is received about the axial slot to secure the metal section and ceramic section together. Tabs on the metal section, a gasket between the metal section and the ceramic section, and springs within the clamp deform an amount that is greater than a thermal expansion difference between the metal section and the ceramic section to maintain a clamping force of the clamp.

Abstract: A method and apparatus to facilitate reducing NOx emissions in turbine engines is provided. The method includes providing an annular shell including a plurality of circumferentially extending panels. The plurality of circumferentially extending panels includes a first panel positioned at an upstream end of the shell and a second panel positioned downstream from, and adjacent to, the first panel. The method also includes forming a plurality of primary dilution holes in the first panel and forming a plurality of secondary dilution holes in the second panel. The dilution holes are configured to discharge dilution air into the shell.

Abstract: A method for fabricating a combustor liner for a gas turbine engine is provided. The method includes providing an annular shell including a plurality of circumferentially extending panels, wherein the plurality of circumferentially extending panels includes a first panel positioned at an upstream end of the shell and a second panel positioned downstream from, and adjacent to, the first panel. The method also includes forming a plurality of primary dilution holes in the first panel and forming a plurality of secondary dilution holes in the second panel, wherein the primary and secondary dilution holes are configured to discharge dilution air into the shell.

Abstract: Improved alcohol reforming processes and reformed alcohol power systems utilizing those processes are disclosed. In preferred embodiments, the alcohol reforming processes utilize a thermally conductive reforming catalyst that allows efficient, low-temperature reforming of an alcohol fuel to produce a reformate gas mixture comprising hydrogen. The present invention makes possible the efficient utilization of alcohol fuels in an internal combustion engine to generate electrical or mechanical power such as in vehicular applications.

Abstract: A method for testing a cooling system for use in a gas turbine engine control system is provided. The method includes connecting an inlet of the cooling system to a differential pressure sensor, connecting an outlet of the cooling system to the differential pressure sensor, and determining whether or not a difference in pressure exists between the inlet and outlet, wherein such a pressure difference is indicative of whether cooling fluid is flowing through the cooling system.

Abstract: The invention concerns a method in which oxygen and/or nitrogen is extracted from an air separation unit. The oxygen that is extracted is directed toward a gasifier, and the nitrogen that is extracted is directed toward a gas turbine. At least one parameter related to each gas stream is controlled by acting upon a compressor located within this gas stream's path, and by assigning to that gas stream a parameter, which is related to a variable setpoint value, which represents the load of the gas turbine.

Abstract: A casing for a gas turbine includes a construction providing improved structural efficiency. Improved load paths and means for transmitting loads in the engine case are disclosed.

Abstract: The invention concerns a turbine engine annular combustion chamber, comprising longitudinal walls (6, 8) connected by a transverse chamber bottom (10) and a single-piece cowling (12), the chamber bottom (10) and the cowling (12) each comprising an inner flange (16, 20) and an outer flange (18, 22) each with a plurality of holes made in it for the passage of fixing systems (14a, 14b) for fixing the cowling on the chamber bottom. Each fixing system has associated with it at least one tangential slot (30) formed on the corresponding flange (16, 18) of the chamber bottom (10) and/or on the corresponding flange (20, 22) of the cowling (12), each slot (30) being formed in the immediate vicinity of the corresponding fixing system (14a, 14b).

Abstract: A method for transferring heat from a first location to a second location includes thermoelelectrically transferring heat from the first location to a third location; and transferring heat from the third location to the second location through a magneto-hydrodynamic (MHD) flow. A cooling system includes a thermoelectric cooling (TEC) component; and a magnetohydrodynamic (MHD) component, wherein the MHD component and the TEC component are in thermal contact.

Abstract: An apparatus for cooling food, in particular water-based beverages, includes a cold accumulator (6) that contains a phase transition material. A conduit (8) for a water-based liquid that is to be chilled is guided through the cold accumulator (6). Also provided is a device (2) for dissipating heat from the cold accumulator (6). In order to make such an apparatus less expensive, easier to produce, and more effective, the cold accumulator (6) is made from a composite material containing expanded graphite and a phase transition material that undergoes a solid-liquid phase transition at or above 273 K.

Abstract: Apparatus transports rod(s) of ice of flaked or chipped ice through a tube to a remote ice bin, in which the ice is broken into nuggets. A method of cleaning the transport tube is also provided in which ice pushes a dry conformable article and a wet conformable articles carrying sanitizing solution through the tube, with the conformable articles preferable being sponges, and with the wet article sanitizing algae, bacteria, etc. during movement through the tube, and with the dry conformable article scraping debris from wall(s) of the tube during transport.

Abstract: An outdoor unit of an air conditioner includes a main body casing, at least one shut-off valve, a shut-off valve cover, a conduit mounting plate, and a shielding portion. The at least one shut-off valve is attached to an outer surface of the main body casing and connected to a refrigerant pipe. The shut-off valve cover has an opening through which the refrigerant pipe passes. The shut-off valve cover covers the shut-off valve. The conduit mounting plate is attached at a position on the outer surface of the main body casing in an interior space in the shut-off valve cover. The shielding portion is disposed around the conduit mounting plate. The shielding portion prevents an intruding object that intrudes into the shut-off valve cover through the opening from contacting an electric wire extending out from a conduit mounted to the conduit mounting plate.

Abstract: In the conventional fumigation of the rooms required to be sterilized, formaldehyde is general used, but formaldehyde has such problems as carcinogenicity and residual tendency. It is also proposed to combine fumigation and air conditioning for automation, but air conditioning and fumigation cannot be performed concurrently.

Abstract: Vapor compression air conditioning systems are provided with a flow restrictor for transferring working fluid to and from at least one of the compressor low pressure inlet conduit and compressor high pressure outlet conduit to provide for accurate charge adjustment to achieve predetermined fluid sub-cooling. Pressure and temperature measurements are taken at a condenser fluid outlet conduit and provided to a microcontroller for determining fluid sub-cooling and comparing sub-cooling with a predetermined target sub-cooling. A charge addition or recovery apparatus may include a solenoid valve controlled by the microcontroller to more accurately control the addition or recovery of refrigerant fluid charge.

Abstract: A subcooling heat exchanger and subcooling expansion valve in a refrigeration system provide subcooling of a pre-subcooled portion, for refrigerating a thermal load, of condensed refrigerant liquid by a pre-subcooling portion of the condensed refrigerant liquid. The amount of subcooling of the pre-subcooled portion is determined by measuring, with a pressure sensor, refrigerating suction pressure exerted by refrigerating compressors of the system. A controller then controls, based on the refrigerating suction pressure, modulation of mass of pre-subcooling portion, relative pre-subcooled portion, and expansion thereof in the subcooling expansion valve, which controls the amount of refrigerant heat exchanged, and therefore subcooling of pre-subcooled portion, between the pre-subcooling portion and the pre-subcooled portion in the subcooling heat exchanger. The pre-subcooling portion is then subsequently compressed by a subcooling compressor.

Abstract: In an air-conditioning system for a vehicle, which has multiple heat sources (an evaporator and a heat accumulator), either one of the heat sources, for which the input energy amount for the unit cooling capacity is smaller than that for the other heat source, is preferentially used for performing the cooling operation, an energy amount for the air-conditioning operation can be reduced.

Abstract: The present invention relates to a refrigerator to be built into surrounding cabinetry having a body having a cavity for food preservation, at least two thin side panels, a thin top panel, and at least one thin front panel. The side panels, top panel, and front panel have a finish that matches the surrounding cabinetry and are removably mounted to the body, thereby maintaining the original volume and structural stiffness of the refrigerator.

Abstract: A Cold Plate Refrigeration System Optimized for Energy Efficiency is provided utilizing two refrigerant compressors and a single set of cold plates; or two refrigerant compressors, a conventional evaporator to air heat exchanger, and a single set of cold plates; or a single refrigerant compressor, a conventional evaporator to air heat exchanger, and a single set of cold plates. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: A water dispenser in a refrigerator door can include a filter casing in the door opening into the bottom of the dispenser housing. The filter casing can include a top wall positioned in the bottom of the dispenser housing, a head assembly at the bottom of the filter casing connected to the water supply and to a water outlet in the dispenser, and can include a filter casing drain. A filter cartridge in the filter casing can connect to the head assembly. The filter casing can include a filter retainer mounted adjacent the opening into the filter casing and can hold the filter cartridge connected to the head assembly in a first position and can release the filter cartridge in a second position. The filter casing can include a drain line leading from the filter casing drain to a pan outside the refrigerated space.

Abstract: An apparatus and method for combining particulate and soft-serve ice cream is disclosed. The soft serve ice cream is manufactured using N2 vapor.

Abstract: A refrigerator icemaker assembly includes a bin having a bottom wall, as well as first and second pairs of opposing side walls. One of the first pair of opposing side walls includes an opening within which is movably mounted a coupler. The coupler is provided with a recessed portion having formed therein an aperture and a cog member. An auger is rotatably mounted in the bin and includes a first end portion that extends through the aperture of the coupler. A drive member extends into the coupler and drives the auger in a first direction to dispense ice cubes and in a second direction to dispense crushed ice. The driver engages with the cog member when being rotated in the first direction and directly engages the first end of the auger when being driven in the second direction.

Abstract: An icemaking compartment is provided in the refrigerator compartment of a bottom mount refrigerator. An icemaker is within the icemaking compartment. A cold air duct supplies cold air from the freezer compartment to the icemaker. The cold air duct is formed in the rear wall of the refrigerator. A fan controls the flow of air through the cold air duct. A return air duct is provided to direct a portion of the air from the icemaker back to the freezer compartment. An air vent in the icemaker directs another portion of air into the refrigerator compartment.

Abstract: A refrigerator with at least one openable door has a hinge at a pivoting edge of the door allowing the door to open about the pivoting edge. A water dispenser, positioned on the door, has a paddle which is moved horizontally by a user to cause water to be dispensed. The paddle engages a toggle that is attached to the dispenser housing, causing the toggle to rotate into engagement with a microswitch. The microswitch is mounted on a user interface control board which communicates with a power supply electronic control board. The power supply control board operates a water dispenser solenoid valve to cause water to flow to the dispenser when the toggle engages the microswitch. An endcap is secured to an edge of the door adjacent to the pivoting edge. A first conduit extends from the water dispenser to an end within the endcap. A second conduit extends from within the cabinet to an end exterior of the cabinet and within the endcap. An end connector is provided to receive the ends of the first and second conduits.

Abstract: A refrigeration appliance has a cabinet having a first compartment, a second separate compartment and a refrigeration system including a compressor, an evaporator and a condenser. The evaporator is associated with the first compartment to lower a temperature of the first compartment air. A heat exchanger is exposed to the temperature of the first compartment and has a surface area exposed to second compartment air. An air moving device is associated with the second compartment to direct a flow of second compartment air over the heat exchanger surface area and circulate the second compartment air within the second compartment. The cabinet, compartments and heat exchanger are configured such that first compartment air is completely isolated from second compartment air.

Abstract: In order to create a refrigeration system comprising a refrigerant circuit (10), in which a main mass flow (56) of a refrigerant is guided, which may be adapted to different operating conditions in an optimum manner it is suggested that at least two refrigerant compressors (12a, 12b, 12c), which can be switched on individually for the purpose of compressing the main mass flow, be arranged in the refrigerant circuit, that at least two of the refrigerant compressors each have at least one additional compressor stage (70), that each of the additional compressor stages be able to be used optionally for the compression of refrigerant from the main mass flow or for the compression of refrigerant from the additional mass flow (86) and that a control (90) be provided, with which such a number of additional compressor stages for the compression of refrigerant from the additional mass flow can be switched on in a first operating mode as a function of the operation conditions that the expansion cooling device (24, 28) l