An inlet air cooling system used in a gas turbine for supplying power to a refrigerant compressor for compressing refrigerant in a natural gas liquefaction plant includes: an inlet air cooler for cooling inlet air of the gas turbine; chiller motors used for a chiller for cooling coolant supplied to the inlet air cooler; a first variable speed driver for supplying electric power to each of the one or more chiller motors; and an electric generator driven by the gas turbine, wherein the electric generator is electrically connected to the first variable speed driver, and electric power generated by the electric generator can be supplied to each of the chiller motors from the first variable speed driver without using a main power line of an electric power system, which enables efficient electric power supply to the motors via the variable speed driver.

A turbomachine system includes a turbomachine provided with a turbomachine rotor. The turbomachine rotor is comprised of a turbomachine shaft with a first shaft end and a second shaft end. The turbomachine shaft is supported by active magnetic bearings for rotation in a turbomachine casing. The turbomachine system further includes a rotary machine drivingly coupled to the first shaft end, and a first closed cooling circuit adapted to circulate a cooling fluid therein and fluidly coupled to the active magnetic bearings to remove heat therefrom. The closed cooling circuit includes a cooling fluid impeller mounted on the turbomachine shaft for rotation therewith and adapted to circulate the cooling fluid in the closed cooling circuit. The closed cooling circuit further includes a heat exchanger adapted to remove heat from the cooling fluid. A method of operating a turbomachine system is further disclosed.

An expander and motor-compressor unit is disclosed. The unit includes a casing and an electric motor arranged in the casing. A compressor is arranged in the casing and drivingly coupled to the electric motor through a central shaft. Furthermore, a turbo-expander is arranged for rotation in the casing and is drivingly coupled to the electric motor and to the compressor through the central shaft.

A transport refrigeration system (20) is provided. The transport refrigeration system includes: a natural gas engine (26), a compressed natural gas storage tank (60), an artificial aspiration device (70) providing decompressed natural gas and compressed air to the natural gas engine, an electric generation device (24) powered by the natural gas engine and providing an electric output, and a refrigeration unit (22) electrically powered by the electric output of the electric generation device.

A power generating portion formed of a rotor and a stator is provided. The rotor is formed of a ring incorporating a permanent magnet and an impeller. The rotor is regarded as a turbine. An actual flow rate is estimated from a present angular velocity of the turbine and a present torque of the power generating portion, a torque of the power generating portion in which the estimated actual flow rate corresponds to a setting flow rate is calculated and the torque of the power generating portion is controlled based on the calculated torque and a magnetic pole position of the turbine. A measured value detected by a position sensor is used as the magnetic pole position of the turbine, however, when it is determined that reliability does not exist in the position sensor, an estimated value is used.

A gas turbine drive system in mechanical drive configuration is described. The gas turbine drive system comprises a gas turbine engine drivingly connected to a driven turbomachine. The gas turbine engine includes a dry low NOx emission combustor. A gas turbine controller is further provided. The gas turbine controller is arranged and configured for regulating the combustion temperature according to at least one control parameters of the turbomachine so that a lean blowout of the combustor is prevented when a transient event involving the driven turbomachine occurs.

Disclosed is a device for liquefying a fluid, comprising a circuit for fluid to be cooled, the device comprising a set of one or more heat exchangers exchanging heat with the circuit of fluid to be cooled, at least one first cooling system exchanging heat with at least some of the set of one or more heat exchangers, the first cooling system being a refrigerator with refrigeration cycle of a cycle gas mostly comprising helium, the refrigerator comprising, arranged in series in a cycle circuit: a cycle gas compression mechanism at least one cycle gas cooling member, a mechanism for expansion of the cycle gas and at least one expanded cycle gas heating member, wherein the compression mechanism comprises at least four compression stages in series, consisting of a set of one or more centrifuge-type compressors, the compression stages being mounted on shafts rotated by a set of one or more motors, the expansion mechanism comprising at least three expansion stages in series, consisting of a set of centripetal turbines, the at least one cycle gas cooling member being configured to cool the cycle gas at the outlet of at least one of the turbines and wherein at least one of the turbines is coupled to the same shaft as at least one compression stage so as to supply the compression stage with the mechanical work produced during the expansion.

The subject matter disclosed herein relates to a liquefaction system. Specifically, the present disclosure relates to systems and methods for condensing a pressurized gaseous working fluid, such as natural gas, using at least one turboexpander in combination with other cooling devices and techniques. In one embodiment, a turboexpander may be used in combination with a heat exchanger using vapor compression refrigeration to condense natural gas.

In some aspects, the techniques described herein relate to a refrigerant compressor, including: a stator; a rotor configured to rotate with respect to the stator; and at least one step seal between the rotor and the stator, wherein the step seal includes a first tooth and a second tooth extending from the rotor toward the stator, wherein a downstream surface of the first tooth and an upstream surface of the second tooth are arranged at an angle relative to one another, wherein the angle is less than 90.

A method for capturing carbon dioxide from a flue gas includes (i) removing moisture from a flue gas to yield a dried flue gas; (ii) compressing the dried flue gas to yield a compressed gas stream; (iii) reducing the temperature of the compressed gas stream to a temperature T.sub.1 using a first heat exchanger; (iv) reducing the temperature of the compressed gas stream to a second temperarature T.sub.2 using a second heat exchanger stream, where T.sub.2<T.sub.1 and at least a portion of the carbon dioxide from the compressed gas stream condenses, thereby yielding a solid or liquid condensed-phase carbon dioxide component and a light-gas component; (v) separating purities the condensed-phase component from the light-gas component to produce a condensed-phase stream and a light-gas stream; and (vi) using at least a portion of the condensed-phase stream and/or the light-gas stream in the second heat exchanger.