There is provided a system and method for producing liquefied natural gas (LNG). An exemplary method includes flowing a high-pressure stream of LNG through a first series of liquid turbines. The exemplary method also includes generating electricity by reducing the pressure of the high-pressure stream of LNG to form a low-pressure stream of LNG. The exemplary method additionally includes bypassing any one the liquid turbines that has a failure while continuing to produce electricity from the first series.

A centrifugal compressor includes a casing, an impeller, a motor, a diffuser, a magnetic bearing, and a magnetic bearing backup system including at least one dynamic gas bearing and at least one hydrostatic gas bearing. The impeller is attached to a shaft rotatable about a rotation axis. The motor is configured and arranged to rotate the shaft in order to rotate the impeller. The magnetic bearing rotatably supports the shaft. The magnetic bearing backup system is configured and arranged to support the shaft when the magnetic bearing stops operating. The at least one dynamic gas bearing and the at least one hydrostatic gas bearing of the magnetic bearing backup system are disposed radially inwardly relative to the magnetic bearing.

A compressor includes: a cylinder defining a compression space, a piston structure accommodated in the cylinder and including a mount member and a guide member, the guide member being configured to reciprocate inside the compression space of the cylinder in an axial direction to compress a refrigerant gas therein and a magnet frame configured to support a mover, the mover being coupled to the piston structure and configured to move together with the piston structure. The mount member connects the guide member to the magnet frame and the guide member is configured to be rotated with respect to the mount member.

A rotary compressor is provided that may include at least one vane that is slidably inserted into at least one vane slot provided in a roller or a cylinder so as to separate a compression space into a plurality of compression chambers. The at least one vane has an at least one oil supply groove formed in at least one of axial side surfaces, respectively, facing a main bearing and a sub bearing. The at least one oil supply groove may be longer in a longitudinal direction of the at least one vane than in a widthwise direction of the at least one vane. With this structure, it is possible to suppress friction loss and wear on a friction surface by supplying oil to the friction surface in contact with the at least one vane.

A compressor includes: a case, a compression unit that is provided inside the case and that includes a cylinder and a piston configured to reciprocate inside the cylinder to compress refrigerant, a driving unit that includes a stator disposed inside the case and a plurality of permanent magnets configured to reciprocate with respect to the stator and that is configured to provide a driving force to the compression unit, and a resonator that is configured to reduce noises generated while the compression unit is operated, that is disposed between the compression unit and an inner surface of the case facing the compression unit in an axial direction, and that is spaced apart from the compression unit.

A scroll compressor includes a compression mechanism having fixed and movable scrolls forming a compression chamber, a motor to drive the movable scroll, a casing accommodating the compression mechanism and the motor, a housing accommodated inside the casing, a floating member supported by the housing, a first seal member, and first and second flow passages. An inside of the casing is partitioned into first and second spaces. The floater member can be pushed toward the movable scroll by pressure in a back-pressure space formed between the floating member and the housing. The first seal partitions the back-pressure space into first and second chambers. The first flow passage guides the refrigerant in the middle of compression in the compression mechanism to the first chamber. The second guides the refrigerant discharged from the compression mechanism to the second chamber.

A compressor includes a cylinder configured to form a compressed space of the refrigerant and having a cylindrical shape, a piston configured to reciprocate axially in the cylinder and comprising a guide portion having a cylindrical shape and a head portion disposed in front of the guide portion, an intake valve disposed at a front of the head portion, a fixing member disposed outside the piston, a rod comprising one end disposed at the head portion and configured to extend axially, a first elastic member connected to the fixing member and other side of the rod, a second elastic member disposed to be spaced apart from a rear of the first elastic member and connected to the fixing member and the other side of the rod, and a first spacer insert-injected with the first elastic member and the second elastic member.

This rotary compressor comprises: a casing forming the outer shape; a rolling piston configured to rotate eccentrically in an internal space; a vane configured to contact the rolling piston and divide the internal space into a suction chamber and a compression chamber; and a main suction port connecting the suction chamber to an outside of the cylinder. The rotary compressor also comprises: a cylinder disposed inside the casing; a first flange disposed above the cylinder; and a second flange disposed below the cylinder. The main suction port comprises a sub suction port extending in a direction in which at least one among the first flange and the second flange is disposed, and at least one among the first flange and the second flange has a flow path groove connecting the sub suction port and the suction chamber.

A method for controlling multi-stage centrifugal compressors is provided. The method includes, for each stage of the compressor, defining a Mach ratio and impeller diameter, calculating a minimum required motor drive frequency to operate free from surge conditions for a current head factor and flow reduction device position, and adjusting the flow reduction device position while maintaining an actual motor drive frequency at a acceptable level to achieve a leaving chilled water temperature set point. The method also includes measuring a suction pressure and a discharge pressure and calculating a saturated suction temperature and a saturated discharge temperature for each stage of the compressor. The method further includes calculating an actual minimum motor drive frequency that is the greater of a first actual minimum motor drive frequency and a second actual minimum motor drive frequency associated with a first compressor stage and a second compressor stage of the compressor, respectively.

A rotary compressor is provided that may include at least one vane that is slidably inserted into at least one vane slot provided in a roller or a cylinder so as to separate a compression space into a plurality of compression chambers. The at least one vane has an at least one oil supply groove formed in at least one of axial side surfaces, respectively, facing a main bearing and a sub bearing. The at least one oil supply groove may be longer in a longitudinal direction of the at least one vane than in a widthwise direction of the at least one vane. With this structure, it is possible to suppress friction loss and wear on a friction surface by supplying oil to the friction surface in contact with the at least one vane.