Abstract: A compression system comprises a compressor, an inlet duct, a throttling valve installed in the inlet duct, an outlet duct, an anti-surge valve fluidly coupling the outlet duct with a portion of the inlet duct downstream of the throttling valve and a recycle valve fluidly coupling the outlet duct with a portion of the inlet duct upstream of the throttling valve. Keeping the recycle valve open, the anti-surge valve closed and the throttling valve partially closed allows lowering the pressure of the flow entering the compressor during its start-up.

Abstract: A thermodynamic system containing a working fluid is disclosed. The thermodynamic system comprises at least a working fluid collection vessel (11) adapted to contain a liquid phase and a gaseous phase of the working fluid in thermodynamic equilibrium. A chilling arrangement (51) is functionally coupled to the fluid collection vessel (11) and adapted to remove heat from the working fluid collected in the working fluid collection vessel (11) and thereby reduce pressure in said thermodynamic system. Also disclosed are methods for depressurizing a thermodynamic system containing a working fluid in liquid/gas equilibrium.

Abstract: A method for handling the shutdown of a turbomachine string installed in a plant for the liquefaction of a gaseous product comprising at least two turbomachine strings comprises the steps of detecting the shutdown of a first turbomachine string; promptly increasing the driving torque on a shaft of a second turbomachine string when the shutdown is detected; maintaining the driving torque increase on the shaft of the second turbomachine string until a preset speed of the motor driver is reached or a predetermined period of time expires.

Abstract: A compression system comprises a compressor, an inlet duct, a throttling valve installed in the inlet duct, an outlet duct, an anti-surge valve fluidly coupling the outlet duct with a portion of the inlet duct downstream of the throttling valve and a recycle valve fluidly coupling the outlet duct with a portion of the inlet duct upstream of the throttling valve. Keeping the recycle valve open, the anti-surge valve closed and the throttling valve partially closed allows lowering the pressure of the flow entering the compressor during its start-up.

Abstract: A compressor system is described, including: at least a first compressor having a suction side and a delivery side; an anti-surge line; an anti-surge valve arranged along the anti-surge line and controlled for recirculating a gas flow from the delivery side back to the suction side of the compressor; a heat removal arrangement between the anti-surge valve and the suction side of the compressor.

Abstract: A method of determining a liquid volume fraction in a multi-phase gas is disclosed. The method includes: a) measuring a first compressor operating parameter; b) selecting a tentative liquid volume fraction of the gas processed by the compressor; c) based on stored data representing a compressor operative curve for the tentative liquid volume fraction, determining an estimated value of a second compressor operating parameter, as a function of the first compressor operating parameter; d) measuring an actual value of the second compressor operating parameter; e) comparing the actual value of the second compressor operating parameter to the estimated value of the second compressor operating parameter and determining an error therefrom; f) based on the error, selecting a different tentative liquid volume fraction and repeating (c) to (e) until an error value equal to or lower than an error threshold is obtained.

Abstract: A thermodynamic system containing a working fluid is disclosed. The thermodynamic system comprises at least a working fluid collection vessel (11) adapted to contain a liquid phase and a gaseous phase of the working fluid in thermodynamic equilibrium. A chilling arrangement (51) is functionally coupled to the fluid collection vessel (11) and adapted to remove heat from the working fluid collected in the working fluid collection vessel (11) and thereby reduce pressure in said thermodynamic system. Also disclosed are methods for depressurizing a thermodynamic system containing a working fluid in liquid/gas equilibrium.

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: A method of pressurizing a downstream compressor system operatively connected to an upstream compressor system by using a bleeding line connected at a first end to the downstream compressor system and at a second end at least to one bleeding region or tie-out region of the upstream compressor system.

Abstract: The compressor system comprises a compressor having first compressor stage and a second compressor stage in a back-to-back arrangement. A first gas flow is provided at the suction side of the compressor. A seal arrangement is provided between the first compressor stage and the second compressor stage. A side stream line is in fluid communication with the suction side of the second compressor stage. A side stream valve on the side stream line and a side stream controller are provided, for adjusting the flow of the second gas. An antisurge arrangement comprised of a bypass line and an antisurge valve is arranged at the first compressor stage for preventing surge of the first compressor stage. The side stream controller is configured for reducing the flow of the second gas when an alteration of the pressure ratio across the first compress stag is detected.

Abstract: A method of determining a liquid volume fraction in a multi-phase gas is disclosed. The method includes: a) measuring a first compressor operating parameter; b) selecting a tentative liquid volume fraction of the gas processed by the compressor; c) based on stored data representing a compressor operative curve for the tentative liquid volume fraction, determining an estimated value of a second compressor operating parameter, as a function of the first compressor operating parameter; d) measuring an actual value of the second compressor operating parameter; e) comparing the actual value of the second compressor operating parameter to the estimated value of the second compressor operating parameter and determining an error therefrom; f) based on the error, selecting a different tentative liquid volume fraction and repeating (c) to (e) until an error value equal to or lower than an error threshold is obtained.

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: A compressor system is described, comprising: at least a first compressor having a suction side) and a delivery side); an anti-surge line; an anti-surge valve arranged along the anti-surge line and controlled for recirculating a gas flow from the delivery side back to the suction side of the compressor; a heat removal arrangement between the anti-surge valve and the suction side of the compressor.

Abstract: A method for handling the shutdown of a turbomachine string installed in a plant for the liquefaction of a gaseous product comprising at least two turbomachine strings comprises the steps of detecting the shutdown of a first turbomachine string; promptly increasing the driving torque on a shaft of a second turbomachine string when the shutdown is detected; maintaining the driving torque increase on the shaft of the second turbomachine string until a preset speed of the motor driver is reached or a predetermined period of time expires.

Abstract: A method of pressurizing a downstream compressor system operatively connected to an upstream compressor system by using a bleeding line connected at a first end to the downstream compressor system and at a second end at least to one bleeding region or tie-out region of the upstream compressor system.

Abstract: The compressor system comprises a compressor having first compressor stage and a second compressor stage in a back-to-back arrangement. A first gas flow is provided at the suction side of the compressor. A seal arrangement is provided between the first compressor stage and the second compressor stage. A side stream line is in fluid communication with the suction side of the second compressor stage. A side stream valve on the side stream line and a side stream controller are provided, for adjusting the flow of the second gas. An antisurge arrangement comprised of a bypass line and an antisurge valve is arranged at the first compressor stage for preventing surge of the first compressor stage. The side stream controller is configured for reducing the flow of the second gas when an alteration of the pressure ratio across the first compress stag is detected.