Abstract: An improved motor driven centrifugal refrigerant compressor is disclosed having a housing enclosing a motor, control electronics and moving parts of the compressor, and a fluid pathway for circulating a mixture of low pressure refrigerant and a lubricant around the pathway, the pathway including a lubricant concentrator for coalescing the lubricant of the mixture to lubricate moving parts of the compressor and the pathway also including a convective heat transfer region to cool the motor and control electronics within the housing.

Abstract: An environmental control system disclosed includes a refrigeration loop including a two stage centrifugal compressor having an inlet and an outlet, a condenser having an inlet connected with the compressor outlet and an outlet, and an evaporator having an inlet connected with said condenser outlet and an outlet connected with the compressor inlet, a motor for rotating the compressor, control means responsive to evaporator load for establishing the rate of rotating said compressor, a controllable expansion valve in communication with the refrigeration loop, an expansion valve control to control the setting of the expansion valve, a bypass valve in communication with the refrigeration loop and also in communication with one stage of the compressor, wherein the bypass valve is selectively openable to allow circulated refrigerant to be variably communicated to the stage in communication therewith, and wherein the setting of the expansion valve is also a function of bypass valve operation.

Abstract: An environmental control system disclosed includes a refrigeration loop including a variable speed compressor having an inlet and an outlet, a condenser, an evaporator and variable speed evaporator fan, temperature setpoint apparatus, recirculated air temperature sensor, evaporator, air inlet temperature sensor and an evaporator fan speed control for establishing the speed of the evaporator fan as a function of the desired air temperature and the recirculated air temperature and a compressor speed control for establishing the speed of the compressor as a function of at least the evaporator air inlet temperature and speed of the evaporator fan.

Abstract: An environmental control system disclosed includes a refrigeration loop including a variable speed compressor having an inlet and an outlet, a condenser having an inlet connected with the compressor outlet and an outlet, and an evaporator having an inlet connected with the condenser outlet and an outlet connected with the compressor inlet. The system also includes a variable speed evaporator fan and evaporator fan control for controlling the speed of the evaporator fan and a monitor for monitoring the superheat condition of the refrigerant at the compressor inlet wherein the evaporator fan control controls the speed of the evaporator fan as a function on the value of the superheat condition. A variable speed condenser fan is controlled by a condenser fan speed control that functions in part on the value of the superheat condition.

Abstract: An environmental control system disclosed includes a refrigeration loop including a variable speed compressor having an inlet and an outlet, a condenser, an evaporator and variable speed evaporator fan for moving air across the evaporator, a compressor speed control, a superheat monitor for monitoring the condition at the inlet of the compressor and a primary superheat control responsive to the superheat monitor for establishing the speed of the evaporator fan to maintain a predetermined superheat condition.

Abstract: A laminated plate header, an evaporator and a method for making the same are disclosed. A plurality of plates, having passageways formed therein, are stacked together to form a laminate. The laminate is adapted to fluidly connect between a header inlet and core units of a heat exchanger in the evaporator. The plurality of plates are interleaved in a manner to index selected passageways of the plate such that refrigerant from the inlet is distributed through the passageways to the core units.

Abstract: An apparatus (10) for cooling a vehicle air conditioning system electrical controller (20) includes a chill block (10) in juxtaposition to the controller (20). The chill block (10) includes a channel (22) that forms a cooling groove in heat exchange relation with the controller (20). The chill block (10) receives a portion of the refrigerant being circulated in the system (12). The portion of the refrigerant received expands in the chill block (10) to a saturated vapor and extracts heat from the controller (20) as the heat of vaporization from such expansion.

Abstract: A refrigeration system utilizes a small high speed centrifugal compressor driven by a directly coupled, high frequency, electric motor. The motor has a double-ended shaft which supports the rotors of low pressure and high pressure centrifugal compressor stages. The motor operates in the refrigerant atmosphere so as to eliminate the requirement for rotating shaft seals. High frequency power (3750 Hz) is supplied to the motor, which runs at 75,000 RPM. The system utilizes a novel flash intercooler between the compressor stages.