A compressor includes a diffuser passage configured to receive refrigerant flow from an impeller of the compressor, where the diffuser passage is at least partially defined by a compressor discharge plate of the compressor. The compressor also includes a variable geometry diffuser positioned within the diffuser passage and configured to adjust a dimension of a refrigerant flow path through the diffuser passage, an actuator coupled to the variable geometry diffuser and configured to adjust a position of the variable geometry diffuser within the diffuser passage, and a controller configured to regulate operation of the actuator. The controller is configured to instruct the actuator to adjust the position of the variable geometry diffuser from a first position to a second position using a first force and to adjust the position of the variable geometry diffuser from the second position to a third position using a second force less than the first force, where the variable geometry diffuser abuts the compressor discharge plate in the third position.

A chiller system is provided and includes a compressor, a variable frequency drive (VFD) to drive the compressor at variable frequencies and a chiller controller to ascertain a chiller condition and to command the VFD to drive the compressor at one of the variable frequencies based on the chiller condition at a first sampling rate. The VFD is configured to drive the compressor at the one of the variable frequencies responsive to being commanded by the chiller controller, to ascertain the chiller condition at a second sampling rate, which is substantially higher than the first sampling rate, and to alert the chiller controller accordingly.

This disclosure relates to an axial magnetic bearing for a centrifugal refrigerant compressor, and a corresponding system and method. A centrifugal refrigerant compressor system according to an exemplary aspect of the present disclosure includes, among other things, an impeller connected to a shaft, and a magnetic bearing system supporting the shaft. The magnetic bearing system includes an axial magnetic bearing, which itself includes a first permanent magnet configured to generate a first bias flux, a second permanent magnet axially spaced-apart from the first permanent magnet and configured to generate a second bias flux, and an electromagnet. The electromagnet includes a coil arranged radially outward of the first and second permanent magnets, and the electromagnet is configured to selectively generate either a first control flux or a second control flux to apply a force to the shaft in a first axial direction or second axial direction opposite the first axial direction, respectively.

A vapor-compression system includes a centrifugal compressor configured to increase a pressure of a refrigerant based on at least one of an activation of a device or the device being equal to or above a first threshold temperature. A fluid communication system is configured to provide, to the device, a portion of the refrigerant in a liquid state. The portion of the liquid refrigerant in a liquid state is configured to have a saturation temperature equal to or below the first temperature threshold.

A refrigerating apparatus includes a centrifugal compressor, a capacity control mechanism that controls a capacity of the compressor by changing an opening degree of the capacity control mechanism, an expansion mechanism that reduces a pressure of a refrigerant, and a controller. The controller calculates an opening degree of the expansion mechanism using compressor capacity as one of a plurality of indices of change in load. The compressor capacity is obtained from a current rotation number of the compressor, an opening degree of the capacity control mechanism, and a divergence rate of a current operation head from a surge region.

A refrigerating apparatus includes a centrifugal compressor, a capacity control mechanism that controls a capacity of the compressor by changing an opening degree of the capacity control mechanism, an expansion mechanism that reduces a pressure of a refrigerant, and a controller. The controller calculates an opening degree of the expansion mechanism using compressor capacity as one of a plurality of indices of change in load. The compressor capacity is obtained from a current rotation number of the compressor, an opening degree of the capacity control mechanism, and a divergence rate of a current operation head from a surge region.

Cooling devices for use with electric submersible pump motors include a refrigerator attached to the end of the electric submersible pump motor with the evaporator heat exchanger accepting all or a portion of the heat load from the motor. The cooling device can be a self-contained bolt-on unit, so that minimal design changes to existing motors are required.

An isothermal turbo-compressor-condenser-expander (ITCCE) includes heat-transferring fan blades that are mounted on, or surround, individual conduits to promote air exchange and heat transfer. In operation, the open framework rotates in free air to promote heat exchange. An ITCCE bladed assembly includes a driven central hub assembly with a first fluid coupling. A first inner plenum is in fluid communication with the fluid coupling. A plurality of compressor multiport conduits extend radially, and pass fluid from, the first inner plenum to an outer plenum that acts as an equalizing line. A return path is provided to the fluid coupling from the outer plenum. The conduits can be formed as metal extrusions, including internal ribs that separate a plurality of ports formed therebetween along an entire length of the conduits. The conduits can define an airfoil shape and/or are axially twisted, generating axial airflow. The return path can include return multiport conduits.

An isothermal turbo-compressor-condenser-expander (ITCCE) includes heat-transferring fan blades that are mounted on, or surround, individual conduits to promote air exchange and heat transfer. In operation, the open framework rotates in free air to promote heat exchange. An ITCCE bladed assembly includes a driven central hub assembly with a first fluid coupling. A first inner plenum is in fluid communication with the fluid coupling. A plurality of compressor multiport conduits extend radially, and pass fluid from, the first inner plenum to an outer plenum that acts as an equalizing line. A return path is provided to the fluid coupling from the outer plenum. The conduits can be formed as metal extrusions, including internal ribs that separate a plurality of ports formed therebetween along an entire length of the conduits. The conduits can define an airfoil shape and/or are axially twisted, generating axial airflow. The return path can include return multiport conduits.

A temperature control apparatus (70) includes a heat exchanger (71) configured to exchange heat with the surroundings using a phase change of a refrigerant, a rotary pump (73) configured to receive the refrigerant from the heat exchanger (71) and fuse the refrigerant with oil contained inside the rotary pump, and an oil water separator (74) configured to receive the refrigerant fused with the oil from the rotary pump (73) and separate the refrigerant from the oil. The temperature control apparatus further includes a refrigeration cycle that implements a cooling function by circulating the refrigerant separated from the oil back to the heat exchanger (71).