Abstract: A gas turbine engine has a cycle operability parameter ? in a defined range to achieve improved overall performance, taking into account fan operability and/or bird strike requirements as well as engine efficiency. The defined range of cycle operability parameter ? may be particularly beneficial for gas turbine engines in which the fan is driven by a turbine through a gearbox.

Abstract: A gas turbine engine generates noise during use, and one particularly important flight condition for noise generation is take-off. A gas turbine engine has high efficiency together with low noise, in particular from the bypass flow exiting the engine. The average velocity of the flow at the exit to the bypass duct is in the range of from 200 m/s to 275 m/s at a take-off lateral reference point, defined as the point on a line parallel to and 450 m from the runway centre line where the Effective Perceived Noise Level (EPNL) is a maximum during take-off.

Abstract: The present disclosure generally relates to monolithic superstructures for supporting a rotating shaft coupled to a rotor relative to a stator. An integral superstructure supports the rotating component. The superstructure includes a bearing portion that contacts the shaft. A stator portion, is spaced a critical dimension radially outward, from the rotor. A first annular transfer portion extends axially forward from the bearing to the stator portion. A second annular transfer portion extends axially aft from the stator portion to a mounting flange. The mounting flange connects the superstructure to a frame. The superstructure maintains a critical dimension between the rotor and the stator as the temperature of the superstructure increases. The rotor may be a compressor impeller in a gas turbine engine and the stator may be an aero component that transfers air into a combustor.

Abstract: An assembly for a gas turbine engine according to an example of the present disclosure includes, among other things, a gas turbine engine component that has a first interface portion, and a support that has a mounting portion and a second interface portion, the mounting portion attachable to an engine static structure, a first retention feature that releasably secures the first interface portion to the support in a first installed position of the gas turbine engine component, and a second retention feature dimensioned to secure the first interface portion to the second interface portion in a second installed position of the gas turbine engine component. The first installed position differs from the second installed position, and one of first and second retention features is dimensioned to carry the gas turbine engine component in response to release of another one of the first and second retention features. A method of sealing for a gas turbine engine is also disclosed.

Abstract: Method for controlling a compressor comprising a last stage (40) and a compressor load controller (90), a set point outlet pressure corresponding to the consumer needed pressure, being given in the load controller (90) comprising the steps of: a—measuring the temperature at the inlet of the last stage (40), b—measuring the ratio between the outlet and inlet pressure of the last stage (40), c—computing a coefficient (?) based on the value of the inlet temperature (Tin) and on the pressure ratio (Pout/Pin), d—if the coefficient (?) is in a predetermined range, changing the set point outlet pressure by a new greater set point outlet pressure until the coefficient (?) computed with the new set point outlet pressure goes out of the predetermined range, and e—adapting the pressure of the fluid coming out of the compressor in a pressure regulator (100) to the consumer needed pressure.

Abstract: A method of starting a gas turbine engine is generally provided. The engine includes a rotor assembly including a compressor rotor and a turbine rotor each coupled to a shaft. The rotor assembly is coupled to a bearing assembly within a casing enabling rotation of the rotor assembly. The method includes determining, based on a lubricant parameter, a period of time within which a rotational speed of the rotor assembly is maintained within a bowed rotor mitigation speed range; rotating the rotor assembly for the period of time within the bowed rotor mitigation speed range; and accelerating the rotor assembly to the combustion speed to ignite a fuel-oxidizer mixture for combustion.

Abstract: An assembly fixture for a fan casing of a gas turbine engine wherein the fan casing includes a casing having a flange with a plurality of apertures extending therethrough, comprises a locating structure having a positioning feature that is engageable by a fastener extending through a particular aperture of the plurality of apertures to secure the locating structure to the fan casing. The locating structure further includes a locating feature indicating a particular location of the fan casing when the locating structure is mounted to the fan casing.

Abstract: Systems and methods for measuring the clearance gaps between rotating and stationary components of a turbomachine are provided. In one exemplary aspect, flexible and degradable sensing arrays that include a plurality of microwave sensors are utilized to sense the clearance gaps between rotating and stationary components of the turbomachine. Microwaves generated by a microwave generator are transmitted to the sensors. Upon rotation of the rotating components, the rotating components reflect the microwaves transmitted thereto. The microwave sensors capture the transmitted signal and also capture a reflected signal indicative of the transmitted signal reflected by the rotating components. The signals are then forwarded to a computing device for processing. The amplitude difference at the interference fringes between the superimposed signals is representative of the clearance gaps between the rotating and stationary components.

Abstract: An assembly for a gas turbine engine includes ceramic material containing (i.e. ceramic matrix composite) segments and joints that couple the segments together.

Abstract: A leading-edge shield for a turbomachine blade includes a pressure-side wing and a suction-side wing. Both the pressure-side wing and suction-side wing extend heightwise from a bottom edge to a top edge and lengthwise from the leading edge to a respective rear edge. They are connected together via the leading edge. The rear edge of the suction-side wing presents at least one shaped segment that is shaped in such a manner that the length of the suction-side wing within this segment is shorter than the length of the suction-side wing at each end of this segment.

Abstract: A gas turbine engine includes a gearbox receiving input from a core shaft and driving a fan at a lower speed than the core shaft. First and second oil circuits fluidly couple with an inlet and outlet of the gearbox. A third oil circuit fluidly couples with an inlet and outlet of the gearbox. The outlet of the gearbox includes a device directing oil from the gearbox to the first oil circuit, to the second oil circuit and to the third oil circuit when feeding to the gearbox exceeds a predefined oil flow rate, or deviates an operational value corresponding with that oil flow rate, and directs oil from the gearbox to the third oil circuit when feeding to the gearbox is ? the predefined flow rate or is ? a corresponding operational value or is greater than or equal to a further corresponding operational value.

Abstract: A method of controlling noise produced by a wind turbine is disclosed. The wind turbine comprises one or more component cooling devices, and the method comprises: receiving one or more inputs indicative of noise generated by the one or more component cooling devices; determining the contribution of noise from the one or more component cooling devices to overall turbine noise based upon the one or more inputs; and modifying turbine operation based upon the contribution of cooling device noise to overall turbine noise and based upon turbine noise requirements. A corresponding wind turbine controller is also provided.

Abstract: A control system and method utilizing one or more processors that are configured to determine contaminant loading of blades of a turbomachinery compressor based on one or more environmental conditions to which the turbomachinery compressor is exposed and one or more atmospheric air inlet conditions of the turbomachinery compressor. The one or more processors then determine a corrosion contaminant concentration on the blades of the turbomachinery compressor based on the contaminant loading that is determined and determine an upper limit on or a distribution of potential corrosion of the blades of the turbomachinery based on the corrosion contaminant concentration, at least one of the environmental conditions to which the turbomachinery compressor is exposed, and the corrosion contaminant concentration that is determined.

Abstract: The present invention relates to a turbine arrangement driven by exhaust gases from a combustion engine. The turbine arrangement comprises a turbine housing, a turbine wheel rotatably arranged in the turbine housing, a first volute section defining a curved flow passage extending about 360° around the periphery of the turbine wheel, and an inner radial passage directing exhaust gases radially inwardly from the flow passage into a swept area of the turbine wheel. The curved flow passage has a cross section area decreasing continuously in the flow direction of the exhaust gases from an initial area at an initial angular position of the curved flow passage to an end angular position. The flow area decreases continuously with a successively reduced value from the initial angular position to an angular position located at least 270° from the initial angular position.

Abstract: An electrical submersible pump (ESP) for use in a high viscosity pumping system includes a pump shaft, at least one rotating impeller including an impeller hub and one or more impeller vanes projecting from the impeller hub. Each of the one or more impeller vanes includes an impeller vane edge, and at least one stationary diffuser positioned below the at least one rotating impeller. A diffuser includes a diffuser hub and a diffuser shroud including a diffuser shroud surface. The impeller vane edge and the diffuser shroud surface are separated only by a clearance gap.

Abstract: Various methods and systems are provided for detecting surge of a turbocharger during engine operation. As one example, a system includes an engine coupled to a low pressure turbocharger and a high pressure turbocharger; and a controller with non-transitory instructions stored in memory that when executed during operation of the engine cause the controller to: indicate an occurrence of surge of the high pressure turbocharger in response to a deviation of a modeled speed of the high pressure turbocharger from a measured speed of the high pressure turbocharger by a threshold amount, where the modeled speed tracks the measured speed during non-surge conditions, as engine operating conditions change.

Abstract: A gas turbine is equipped with: a low-pressure bleed passage, a medium-pressure bleed passage, and a high-pressure bleed-passage for supplying compressed air bled from respective bleed chambers to a turbine; a low-pressure exhaust passage, a medium-pressure exhaust passage, and a high-pressure exhaust passage for exhausting the compressed air in the respective bleed passages to an exhaust chamber; a low-pressure exhaust valve, a medium-pressure exhaust valve, and a high-pressure exhaust valve provided respectively in the exhaust passages; a low-pressure ejector and a medium-pressure ejector provided in the respective exhaust passages; a driving air supply passage for supplying the compressed air to the ejectors; and a control device configured to open the exhaust valves and supply compressed air from the driving air supply passage to the ejectors when an operating state of a gas turbine is in a region in which rotation stall is generated.

Abstract: A control system is disclosed. The control system includes a wind turbine, at least one sensor configured to detect at least one property of the wind turbine to generate measurement data, and a controller communicatively coupled to the wind turbine and the at least one sensor. The controller includes at least one processor in communication with at least one memory device. The at least one processor is configured to control, during a training phase, the wind turbine according to at least one test parameter, receive, from the at least one sensor, during the training phase, first measurement data, generate, based on the at least one test parameter and the received first measurement data, a control model, receive, during an operating phase, second measurement data from the at least one sensor, and update the control model continuously based on the second measurement data.

Abstract: A wind turbine uses a series of airfoils/vanes that rotate in a vertical plane within a specifically designed housing. The housing has several adjustable surfaces that control airflow patterns within the housing to increase wind velocity through a vortex effect.

Abstract: A turbocharger includes a turbine with a housing and a rotor for expanding a first medium; a compressor with a housing and a rotor for compressing a second medium utilizing energy extracted in the turbine during expansion of the first medium. A housing surrounds the turbine housing and/or the compressor housing and/or the bearing housing at least in sections, which housing is at least formed from a first housing section and a second housing section, which are connected to one another via screw connections. On the first housing section, shearing force absorption elements are formed or fastened which extend through the second housing section and in the event that shearing forces occur, absorb the shearing forces and thus relieve the screw connections of the shearing forces.

Abstract: A blood pump assembly comprising a pump casing, at least a portion of which is disposed around one or more blades coupled to a drive cable, and a motor configured to drive the drive cable and the one or more blades rotationally, wherein the drive cable is configured to undergo axial displacement with respect to the pump casing during rotation.

Abstract: A method for controlling a compression system that includes a compressor for compressing gas, a first on-off valve provided on a suction flow passage connected to a suction side of the compressor, a pressure reducing valve provided on a portion of the suction flow passage upstream of the first on-off valve, a second on-off valve provided on a discharge flow passage connected to a discharge side of the compressor, a bypass flow passage connecting the suction flow passage and the discharge flow passage to detour the compressor, and a bypass valve provided on the bypass flow passage, includes closing the first on-off valve while driving the compressor, opening the bypass valve simultaneously with or after the closing of the first on-off valve, closing the second on-off valve after the opening of the bypass valve, and continuing to drive the compressor after the closing of the second on-off valve.

Abstract: Provided is a flow meter capable of logging data more reliably. In this operation, a detection element repeatedly detects a physical quantity related to a flow rate of a fluid flowing in a pipe in a predetermined sampling cycle. Based on physical quantities, a calculation part sequentially calculates the flow rate of the fluid in the pipe. Further, a time measurement part calculates the time. A control storage part is caused to store a logging target, a logging cycle, and logging start definition information. Based on the logging start definition information, a control part automatically starts logging of the logging target in response to startup of the flow meter, and causes a log storage part to store the time measured by the time measurement part and a numerical value of the logging target in association with each other in every logging cycle.

Abstract: According to the present invention, part of carbon dioxide heated by a heater is supplied to a dry gas seal portion of a compressor so that a device for pressurizing and heating a seal gas is not additionally required, configuration can be simplified and cost can be reduced. In addition, a seal gas flow path includes a low-temperature seal gas flow path and a high-temperature seal gas flow path so that, in an initial driving mode, carbon dioxide heated by a high-temperature portion of the heater is used as a seal gas and in a turbine-driving mode, carbon dioxide heated by a low-temperature portion of the heater is used as a seal gas and thus a more efficient operation can be performed.

Abstract: A booster system for increasing pressure of an object gas includes: a first compression unit that compresses the object gas to intermediate pressure equal to or higher than the critical pressure and lower than the target pressure and generates an intermediate supercritical fluid; a cooling unit that cools the intermediate supercritical fluid with a cooling medium and generates an intermediate supercritical pressure liquid; a liquid extracting and pressure reducing unit that extracts a part of the intermediate supercritical pressure liquid; a flow regulating valve that regulates a flow rate of the extracted part of the intermediate supercritical pressure liquid; a second compression unit that increases pressure of the rest of the intermediate supercritical pressure liquid to be equal to or higher than the target pressure; and a pressure sensor that detects pressure of the intermediate supercritical pressure liquid.

Abstract: Variable vane devices containing rotationally-driven translating vane structures are provided, as are methods for fabricating variable vane devices. In one embodiment, the variable vane device includes a flow assembly having a centerline, an annular flow passage extending through the flow assembly, cam mechanisms, and rotationally-driven translating vane structures coupled to the flow assembly and rotatable relative thereto. The translating vane structures include vane bodies positioned within the annular flow passage and angularly spaced about the centerline. During operation of the variable vane device, the cam mechanisms adjust translational positions of the vane bodies within the annular flow passage in conjunction with rotation of the translating vane structures relative to the flow assembly.

Abstract: According to an example embodiment, a gas turbine engine assembly includes, among other things, a fan section including a fan, the fan including a plurality of fan blades, a diameter of the fan having a dimension D that is based on a dimension of the fan blades, each fan blade having a leading edge, and a forward most portion on the leading edges of the fan blades in a first reference plane, a turbine section including a high pressure turbine and a low pressure turbine, the low pressure turbine driving the fan, a nacelle including an inlet portion forward of the fan, a forward edge on the inlet portion in a second reference plane, and a length of the inlet portion having a dimension L measured along an engine axis between the first reference plane and the second reference plane. A dimensional relationship of L/D is no more than 0.45.

Abstract: Apparatus (200) for sorting mixed waste materials, comprising: a housing (260) configured to be vibrated to assist sorting; a screen (210) supported by the housing (260) and having an inlet end (212) for receiving waste materials and an outlet end (214) for discharging at least some waste received at the inlet end (212), the screen (210) comprising at least one portion (220) pivotally coupled adjacent the inlet end (212) to a substantially horizontal axle (222) mounted in the housing (260); and drive means (224,228) configured to pivot the at least one portion (222) of the screen (210) about the axle (222) with a controlled reciprocating action.

Abstract: A highly efficient gas turbine engine is provided. The fan of the gas turbine engine is driven from a turbine via a gearbox, such that the fan has a lower rotational speed than the driving turbine, thereby providing efficiency gains. The efficient fan system is mated to a core that has low cooling flow requirements and/or high temperature capability, and which may have particularly low mass for a given power.

Abstract: A method is described for providing antisurge control in a system comprising a compressor having at least an upstream compressor stage, a downstream compressor stage and a side stream bringing flow into a flow passage between the upstream compressor stage and the downstream compressor stage. The method provides for estimating a temperature of a flow delivered by the upstream compressor stage using a non-dimensional performance map of the upstream compressor stage and further estimating a temperature of a flow entering the downstream compressor stage based on the mass flow and flow temperature of the flow delivered by the downstream compressor stage and the mass flow and the flow temperature of the side stream. The method further provides for performing antisurge control of the downstream compressor stage based on the temperature of the flow entering the downstream compressor stage.

Abstract: The present invention relates to a method and control system to control the speed of centrifugal compressors operating within a vacuum pressure swing adsorption process to avoid an operation at which surge can occur and directly driven by an electric motor that is in turn controlled by a variable frequency drive, while subsequently operating the vacuum pressure swing process between set limits of highest adsorption and lowest desorption pressure. In accordance with present invention an optimal speed for operation of the compressor is determined at which the compressor will operate along a peak efficiency operating line of a compressor map thereof. This speed is adjusted by a feed back speed multiplier when the flow or other parameter referable to flow through the compressor is below a minimum and a feed forward multiplier during evacuation and evacuation with purge steps that multiplies the feed back multiplier to increase speed of the compressor and thereby avoid surge.

Abstract: A turbine housing section includes a radially inner case centered on a first axis, and a radially outer case spaced radially outwardly of the inner case, and centered on a second axis. The first and second axes are offset relative to each other. A plurality of tie rods include a threaded nut received on a tie rod, with the plurality of tie rods connecting the inner and outer cases. The plurality of tie rods are spaced circumferentially about both of the first and second axes, and extend for distinct lengths between the inner and outer cases such that the inner and outer cases are held at a position wherein the first and second axes are offset.

Abstract: A first vibration sensor measures vibration of a bearing. A second vibration sensor for measuring background noise received by the first vibration sensor is installed so as not to receive vibration of the bearing. A data acquisition device receives a first signal that is a measurement signal of the first vibration sensor and a second signal that is a measurement signal of the second vibration sensor and outputs a third signal obtained by subtracting the second signal from the first signal as data indicating vibration of the bearing.

Abstract: A heat exchanging arrangement is integrated within a gas turbine engine case that at least partially encloses a gas turbine engine. The gas turbine engine has an upstream end and a downstream end which are defined by a core fluid flow through the gas turbine engine. The heat exchanging arrangement includes at least one flow passage defined within the gas turbine engine case having an inlet port and an outlet port. The at least one flow passage is configured to direct at least a portion of a fluid flowing through the gas turbine engine from between a downstream position and an upstream position while traveling between the inlet port and the outlet port.

Abstract: A gas turbine engine generates noise during use, and one particularly important flight condition for noise generation is take-off. A gas turbine engine that has high efficiency provides low noise, in particular from the fan and the turbine that drives the fan. Values are defined for a noise parameter NP that results in a gas turbine engine having reduced combined fan and turbine noise.

Abstract: A variable vane actuation system of a gas turbine engine is provided. The variable vane actuation system including: a variable vane; a vane stem operably associated with the variable vane, wherein the variable vane is configured to rotate with the vane stem; a vane arm having vane stem end and a vane pin end opposite the vane stem end, the vane arm being operably connected to the vane stem at the vane stem end; and a rotational variable differential transformer operably connected to the vane stem, the rotational variable differential transformer configured to detect an amount of rotation of the vane stem.

Abstract: A centrifugal compressor according to an exemplary aspect of the present disclosure includes, among other things, an impeller provided in a main flow path and configured to pressurize a main flow of fluid. The compressor also includes a secondary flow path configured to provide a secondary flow by recirculating a portion of the main flow. The amount of the main flow that becomes the secondary flow is less than or equal to 15%. A method is also disclosed.

Abstract: Herein provided are methods and systems for controlling an engine having a variable geometry mechanism. A pressure ratio between a first pressure at an inlet of the engine and a predetermined reference pressure is determined. An output power for the engine is determined. The output power is adjusted based at least in part on the pressure ratio to obtain a corrected output power. A position control signal for a variable geometry mechanism of the engine is generated based on the corrected output power and the pressure ratio. The position control signal is output to a controller of the engine to control the variable geometry mechanism.

Abstract: A gas turbine engine including a torque frame is provided. The torque frame includes an inner shroud defined circumferentially around the axial centerline, an outer shroud surrounding the inner shroud and defined circumferentially around the axial centerline, and a structural member extended along the radial direction and coupled to the inner shroud and the outer shroud. The torque frame is configured to rotate around the axial centerline.

Abstract: A clearance control arrangement (26) for a rotor (28) comprising a segment assembly (33) spaced radially inwards from a casing (32) and defining a radial clearance (42) between the rotor (28) and the segment assembly (33). A front carrier (35a) and a rear carrier (35b) supporting the segment assembly (33). A heat transfer cavity (48) formed between the carriers (35a, 35b), the segment assembly (33) and the casing (32). A settling chamber (60) formed adjacent to the casing (32) and upstream of the heat transfer cavity (48). The clearance control arrangement (26) is configured to receive air into the settling chamber (60) and thence to deliver it to the heat transfer cavity (48).

Abstract: A gas turbine engine includes a first spool including a first compressor coupled to a first turbine through a first shaft, a second spool including a second compressor coupled to a second turbine through a second shaft. A first tower shaft is coupled to the first shaft through a first gear assembly and a second tower shaft is coupled to the second shaft through a second gear assembly. A first load generating device is driven by the first tower shaft and a second load generating device is driven by the second tower shaft. A controller controls each of the first load generating device and the second load generating device to vary a proportion of the total load applied to each of the first spool and the second spool to bias a direction of an axial load on each of the first spool and the second spool.

Abstract: A blade outer air seal assembly includes a support structure. A blade outer air seal extends circumferentially about an axis and is mounted in the support structure. The blade outer air seal has a lip at an axial end engaged with the support structure. A seal structure has a seal portion and a wear liner portion joined by a radially extending portion. The seal portion is radially outward of the lip and the wear liner is radially inward of the lip.

Abstract: A casting plug for a vane of a gas turbine engine includes a plug body a flow control feature and a support that extends between the plug body and the flow control feature.

Abstract: A ceramic matrix composite (“CMC”) center body may be positioned around an austenitic nickel-chromium-based superalloy attachment ring. The attachment ring may be integrally formed with a turbine engine case. The attachment ring may have a greater coefficient of thermal expansion than the center body. A plurality of pins may be inserted through apertures in the center body and coupled to the attachment ring. The pins may slide within the apertures, allowing the attachment ring to expand without applying a load on the center body.

Abstract: A compressor system including: a first compressor having a compressor suction side and a compressor delivery side; an anti-surge line having an inlet and an outlet; an anti-surge valve arranged along the anti-surge line and controlled for recirculating a gas flow from the compressor delivery side back to the compressor suction side; a gas temperature manipulation arrangement, functionally connected to the inlet of the anti-surge line, configured to reduce or prevent liquid phase in the anti-surge line when the anti-surge valve is open.

Abstract: Shroud assemblies and methods for cooling gas turbine engine shrouds are provided. For example, a shroud assembly comprises a shroud segment having hot and cold side portions. The hot side portion faces a gas flow path, and the cold side portion faces a cooling fluid flow path. The shroud assembly further comprises a shroud hanger for mounting the shroud segment in the gas turbine engine. The shroud hanger includes a conduit for receipt of a flow of cooling fluid that defines an outlet configured for the flow of cooling fluid to exit the conduit substantially tangential to the cold side portion of the shroud segment. The shroud and shroud hanger together define an annular cavity that forms the cooling fluid flow path, and fluid exits a plurality of conduits defined in the shroud hanger into the cavity substantially tangential to the shroud cold side to cool the shroud cold side.

Abstract: A device for controlling an air flow in a motor vehicle compartment. The device includes: a frame defining an opening; a plurality of slats extending across the frame, arranged above one another; and an actuator connected to each of the slats by a respective fastener. Each slat extends in a respective air deflection plane, and is movable via the actuator, between: a closed position, in which the slats cooperate with one another to block the passage of the air through the opening, and an open position, in which the slats allow the air to flow through the opening, the deflection planes of the slats intersecting upstream from the frame. Each fastener is mounted rotatably only on the actuator, around a respective actuating axis.

Abstract: There is disclosed a fan assembly including a fan rotor including a hub and fan blades. The fan blades have a leading edge and a trailing edge. A fan stator downstream of the fan rotor relative to a direction of an airflow through the fan assembly. The fan stator includes vanes extending between radially inner ends and radially outer ends. A flow recirculation circuit has an inlet downstream of radially inner ends of the vanes of the fan stator and an outlet upstream of radially inner ends of the vanes. A recirculation stator has a plurality of stationary guide vanes circumferentially distributed around the axis and located in the flow recirculation circuit between the inlet and the outlet A method of operating the fan assembly is also disclosed.

Abstract: An aerial vehicle outfitted with one or more cameras captures a sequence of images of a rotating propeller. The images are processed according to one or more techniques to recognize a position of the propeller, or an angle of orientation of the propeller, in each of the images. The positions or angles of the rotating propeller are used to calculate a rotational speed of the propeller, or a direction of rotation of the propeller. The cameras used to capture the images are also available for use in other applications such as navigation, monitoring or collision avoidance. The propeller may include one or more stripes, colors, characters, symbols or other markings to enhance its visibility and facilitate the determination of positions or angles of the propeller within images.

Abstract: A control method of a centrifugal compressor (C) mechanically coupled to an expansion turbine (TorC), the centrifugal compressor (C) being provided with at least a control system (20) of the absorbed power. The control method of the rotation speed of the turbine-centrifugal compressor group performs the following steps: —acting on the centrifugal compressor control system (20) of the absorbed power by means of a first controller (PID-f), in order to keep constant the rotational speed of the compressor mechanically coupled to the expansion turbine; —ensuring that the centrifugal compressor (C) remains in a stable operating condition by means of an admission valve (Vi) of the expansion turbine (TorC).