Abstract: In one embodiment, a cooling system may include a thermosyphon cooler that cools a cooling fluid through dry cooling and a cooling tower that cools a cooling fluid through evaporative cooling. The thermosyphon cooler may use natural convection to circulate a refrigerant between a shell and tube evaporator and an air cooled condenser. The thermosyphon cooler may be located in the cooling system upstream of, and in series with, the cooling tower, and may be operated when the thermosyphon cooler is more economically and/or resource efficient to operate than the cooling tower. According to certain embodiments, factors, such as the ambient temperature, the cost of electricity, and the cost of water, among others, may be used to determine whether to operate the thermosyphon cooler, the cooling tower, or both.

Abstract: In one embodiment, a cooling system includes a thermosyphon cooler that cools a cooling fluid through dry cooling and a cooling tower that cools a cooling fluid through evaporative cooling. The thermosyphon cooler uses natural convection to circulate a refrigerant between a shell and tube evaporator and an air cooled condenser. The thermosyphon cooler is located in the cooling system upstream of, and in series with, the cooling tower, and is operated when the thermosyphon cooler is more economically and/or resource efficient to operate than the cooling tower. According to certain embodiments, factors, such as the ambient temperature, the cost of electricity, and the cost of water, among others, are used to determine whether to operate the thermosyphon cooler, the cooling tower, or both.

Abstract: In one embodiment, a cooling system includes a thermosyphon cooler that cools a cooling fluid through dry cooling and a cooling tower that cools a cooling fluid through evaporative cooling. The thermosyphon cooler uses natural convection to circulate a refrigerant between a shell and tube evaporator and an air cooled condenser. The thermosyphon cooler is located in the cooling system upstream of, and in series with, the cooling tower, and is operated when the thermosyphon cooler is more economically and/or resource efficient to operate than the cooling tower. According to certain embodiments, factors, such as the ambient temperature, the cost of electricity, and the cost of water, among others, are used to determine whether to operate the thermosyphon cooler, the cooling tower, or both.

Abstract: In one embodiment, a cooling system may include a thermosyphon cooler that cools a cooling fluid through dry cooling and a cooling tower that cools a cooling fluid through evaporative cooling. The thermosyphon cooler may use natural convection to circulate a refrigerant between a shell and tube evaporator and an air cooled condenser. The thermosyphon cooler may be located in the cooling system upstream of, and in series with, the cooling tower, and may be operated when the thermosyphon cooler is more economically and/or resource efficient to operate than the cooling tower. According to certain embodiments, factors, such as the ambient temperature, the cost of electricity, and the cost of water, among others, may be used to determine whether to operate the thermosyphon cooler, the cooling tower, or both.

Abstract: A screw compressor utilizing radial and axial or thrust bearings to maintain the position of the rotors radially and axially and utilizing a damping fluid to dampen rotor vibrations. The damping fluid may conveniently be provided in the form of lubricant that is already used in the compressor to seal the clearances between the rotors and between the rotors and the cylinder during compression. The damping fluid is included in a squeeze film damper, arranged in a parallel arrangement with the radial or thrust bearings, which provides viscous damping to the rotor. The introduction of additional viscous damping such as may be provided by squeeze film dampers may result in significant reduction of compressor vibration regardless of the source of vibration.

Abstract: In one embodiment, a cooling system may include a thermosyphon cooler that cools a cooling fluid through dry cooling and a cooling tower that cools a cooling fluid through evaporative cooling. The thermosyphon cooler may use natural convection to circulate a refrigerant between a shell and tube evaporator and an air cooled condenser. The thermosyphon cooler may be located in the cooling system upstream of, and in series with, the cooling tower, and may be operated when the thermosyphon cooler is more economically and/or resource efficient to operate than the cooling tower. According to certain embodiments, factors, such as the ambient temperature, the cost of electricity, and the cost of water, among others, may be used to determine whether to operate the thermosyphon cooler, the cooling tower, or both.

Abstract: In one embodiment, a cooling system may include a thermosyphon cooler that cools a cooling fluid through dry cooling and a cooling tower that cools a cooling fluid through evaporative cooling. The thermosyphon cooler may use natural convection to circulate a refrigerant between a shell and tube evaporator and an air cooled condenser. The thermosyphon cooler may be located in the cooling system upstream of, and in series with, the cooling tower, and may be operated when the thermosyphon cooler is more economically and/or resource efficient to operate than the cooling tower. According to certain embodiments, factors, such as the ambient temperature, the cost of electricity, and the cost of water, among others, may be used to determine whether to operate the thermosyphon cooler, the cooling tower, or both.

Abstract: In one embodiment, a cooling system may include a thermosyphon cooler that cools a cooling fluid through dry cooling and a cooling tower that cools a cooling fluid through evaporative cooling. The thermosyphon cooler may use natural convection to circulate a refrigerant between a shell and tube evaporator and an air cooled condenser. The thermosyphon cooler may be located in the cooling system upstream of, and in series with, the cooling tower, and may be operated when the thermosyphon cooler is more economically and/or resource efficient to operate than the cooling tower. According to certain embodiments, factors, such as the ambient temperature, the cost of electricity, and the cost of water, among others, may be used to determine whether to operate the thermosyphon cooler, the cooling tower, or both.

Abstract: A screw compressor utilizing radial and axial or thrust bearings to maintain the position of the rotors radially and axially and utilizing a damping fluid to dampen rotor vibrations. The damping fluid may conveniently be provided in the form of lubricant that is already used in the compressor to seal the clearances between the rotors and between the rotors and the cylinder during compression. The damping fluid is included in a squeeze film damper, arranged in a parallel arrangement with the radial or thrust bearings, which provides viscous damping to the rotor. The introduction of additional viscous damping such as may be provided by squeeze film dampers may result in significant reduction of compressor vibration regardless of the source of vibration.

Abstract: A system is provided for maintaining the position of a valve in a compressor. The valve includes a valve body connected to a piston in a cylinder by a shaft. The valve body is positioned in the discharge outlet of the compressor based on the location of the piston in the cylinder. The system maintains the position of the valve body in response to a movement of the piston by permitting fluid to flow from a fluid source through the piston and into a chamber of the cylinder to urge the piston back to its initial position in the cylinder.

Abstract: In one embodiment, a cooling system may include a thermosyphon cooler that cools a cooling fluid through dry cooling and a cooling tower that cools a cooling fluid through evaporative cooling. The thermosyphon cooler may use natural convection to circulate a refrigerant between a shell and tube evaporator and an air cooled condenser. The thermosyphon cooler may be located in the cooling system upstream of, and in series with, the cooling tower, and may be operated when the thermosyphon cooler is more economically and/or resource efficient to operate than the cooling tower. According to certain embodiments, factors, such as the ambient temperature, the cost of electricity, and the cost of water, among others, may be used to determine whether to operate the thermosyphon cooler, the cooling tower, or both.

Abstract: A system is provided for maintaining the position of a valve in a compressor. The valve includes a valve body connected to a piston in a cylinder by a shaft. The valve body is positioned in the discharge outlet of the compressor based on the location of the piston in the cylinder. The system maintains the position of the valve body in response to a movement of the piston by permitting fluid to flow from a fluid source through the piston and into a chamber of the cylinder to urge the piston back to its initial position in the cylinder.

Abstract: A pressurized supply of oil for lubrication and other purposes for a helical screw compressor is automatically and continuously maintained in an oil separator in the compressor discharge line by a check valve assembly which is controlled by the pressure differential between the compressor inlet and the condenser, a bypass around the valve's control element permitting equalization of pressure on its opposite sides to permit closing by a biasing element.

Abstract: An axial flow helical screw compressor with a slide valve and slide stop mounted end to end in communication with the intermeshing rotors has means for changing the volume ratio during operation by stepwise movement of the slide stop and for changing the capacity during operation in infinitely variable fashion, both in response to system operating conditions. In the event of interference between the movements of the slide stop and slide valve, the components are designed so that the movements of the slide stop overpowers that of the slide valve.

Abstract: A variable volume ratio screw compressor has a side load inlet port for the injection of refrigerant vapor into the interlobe volume. In order to improve efficiency, overcompression and undercompression are avoided by varying the location of the radial discharge port to give the compressor an internal volume ratio matched to the pressure of the system in which the compressor operates. This is accomplished in the present application by locating a pressure sensing port no earlier than and preferably later in the compression than the side load injection port, but early enough in the compression that it will not communicate with the discharge port. The pressure that is sensed in the sensing port is used to predict the actual peak pressure in order that maximum efficiency may be obtained as a result of matching the internal volume ratio to the pressure ratio of the system.

Abstract: A method of cooling the oil in screw compressors equipped with automatic variable volume ratio by automatically relocating the proper ports for the injection of liquid refrigerant into the interlobe volume of the compressor in response to the instantaneous internal volume ratio so that the refrigerant injection is done at an optimum time to insure efficient use of the refrigerant.

Abstract: An automatic variable volume ratio screw compressor has a plurality of ports for the injection of liquid refrigerant into the interlobe volume. These ports communicate with the interlobe volume at different effective distances from the discharge port so that the injection of liquid refrigerant may be done at the latest possible time during compression for effective use of the refrigerant, and without risking exposure to the open discharge port.The selection of the port is done automatically in response to the instantaneous internal volume ratio.

Abstract: A radial and thrust bearing mounting particularly adapted for a helical screw type compressor, is provided in which the radial load is isolated from the thrust load to prevent the thrust bearing from carrying any substantial radial load, and in which adjustment of the axial discharge end clearance between the faces of the rotors and the discharge end of the housing cover is provided.