A chilling unit includes a casing, a refrigerant circuit in which a compressor, a heat-source heat exchanger, a first expansion unit, a second expansion unit, and a refrigerant-to-heat medium heat exchanger are connected by a refrigerant pipe and through which refrigerant flows, the refrigerant circuit being placed in the casing, and an injection circuit in which a portion between the first expansion unit and the second expansion unit is connected to the compressor by an injection pipe, the injection circuit being placed in the casing.

A centrifugal compressor for a chiller includes an impeller, a motor, a diffuser, and at least one injection port. The impeller is attached to a shaft rotatable about a rotation axis. The motor is arranged and configured to rotate the shaft in order to rotate the impeller. The diffuser is disposed downstream from the impeller. The at least one injection port is located within the diffuser. The at least one injection port is configured and arranged to supply liquid refrigerant into the diffuser from a condenser or an economizer of the chiller.

To reduce the possibility that temperature of refrigerant discharged from a compressor of a refrigeration apparatus becomes excessively high by controlling torque of a motor built into the compressor, the compressor includes the motor having rotation thereof controlled by inverter control. An inverter controller controls torque of the motor using inverter control when operation frequency of the compressor is at least one value within a range of from 10 Hz to 40 Hz. When at least the operation frequency is within the range of from 10 Hz to 40 Hz, torque of the motor is controlled, and under a predetermined condition in which temperature of refrigerant discharged from the compressor easily becomes excessively high, a device controller controls devices provided in a refrigerant circuit such that refrigerant sucked into the compressor is placed in a wet vapor state.

The present disclosure relates to a new breed of high performance compressors and associated vapor compression systems that can be used in wide ranging refrigeration, cooling and heating applications with significantly increased compressor isentropic efficiency, motor efficiency, reliability and longevity of the motor, the compressor pump and the system as a whole, as well as COP, heating capacity, and SEER of the new vapor compression systems utilizing the new high performance compressors. The design philosophy and modifications to the current configuration of rolling piston rotary compressor to arrive at the high-performance version of the same type will be readily applicable to other types of vapor compression compressors with only minor changes opening the way for adoption of the new design philosophy by the entire compressor industry resulting in serious reduction of carbon footprint for air conditioners, heat pumps and refrigerators worldwide.

A method of controlling injection into a compressor in a refrigeration cycle is described. A refrigeration cycle may comprise at least an economizer heat exchanger, a heat rejection heat exchanger, a first expansion device, and a compressor. A discharge port of the compressor is connected to the heat rejection heat exchanger via a discharge line and an injection port of the compressor is connected to the means for compressing. The economizer heat exchanger comprises a first path having an input connected to the heat rejection heat exchanger and an output connected to the first expansion device, and a second path having an input connected to the heat rejection heat exchanger via an economizer valve and an output connected to the injection port of the compressor via an injection line. The economizer valve is regulated based on a superheat level of the refrigerant in the economizer heat exchanger.

A vapor cycle compressor includes a motor section and a compression section operatively engaged with the motor section. A refrigerant path is in the motor section and in the compression section. The refrigerant path includes: a compression refrigerant path, for a single phase compression refrigerant, in the compression section; an inner rotor shaft refrigerant path, for a single phase inner rotor shaft refrigerant, in the compression section and in the motor section; and a stator refrigerant path, for a two phase stator refrigerant, in the motor section.

A compressor includes: a stator core including a plurality of teeth around which an aluminum winding wire is wound in a concentrated manner; a rotor core disposed on an inner diameter side of the stator core and including a plurality of magnet insertion holes; and a plurality of ferrite magnets inserted in the magnet insertion holes, in which when a width of a winding wire portion formed in each of the teeth is represented as A, a length in an axis direction of the stator core is represented as L, and the number of slots is represented as S, the stator core has a shape that satisfies a relation of 0.3<S×A÷L<2.2.

A HVAC system includes a compressor having a low pressure input and a high pressure output. The compressor is driven by a motor having a liquid coolant flowpath configured to cool and lubricate the motor. The motor has a coolant input and a coolant output. An evaporator is in communication with the compressor, and includes a coolant input and a coolant output. A condenser is in fluid communication with the evaporator and the compressor. A first coolant flowpath, includes a coolant drive system connecting the output of the condenser to a valve switching device. A second coolant flowpath connects the output of the condenser to the input of the evaporator and to a second input of the valve switching device. A third coolant flowpath connects the valve switching device to the inputs of the motor. A fourth coolant flowpath connects outputs of the motor to the input of the evaporator.

A compressor of an air-conditioning device includes a scroll mechanism unit having a fixed scroll and an orbiting scroll that cooperates with the fixed scroll to compress refrigerant. There is a first space portion provided between the scroll mechanism unit and an electric motion unit; an annular second space portion provided in a circumference of the scroll mechanism unit in a radial direction; a communication path provided between the first space portion and the second space portion, to guide, to the second space portion, the refrigerant sucked from the suction pipe to the first space portion. A part of the refrigerant between the first expansion valve and the second expansion valve is injected simultaneously to the first space portion and the second space portion.

A control system includes processing and memory circuitry, the memory circuitry storing a temperature-based capacity control scheme for a chiller system and the processing circuitry being configured to perform the temperature-based capacity control scheme. The motor temperature-based capacity control scheme is performed as a function of a monitored temperature in a motor configured to drive a compressor of the chiller system, a first temperature threshold corresponding to the monitored temperature, and a second temperature threshold corresponding to the monitored temperature higher than the first temperature threshold.