Abstract: A multi-cylinder reciprocating compressor is automatically controlled in terms of two speed operation and selective utilization of the cylinders under single stage action to meet heating and cooling loads by way of a two step indoor thermostat and an outdoor thermostat. The compressor may supply energy to storage during heating and cooling or receive energy therefrom with the storage coil selectively loop connected to the outside or indoor coils. Subcooling return is directed to a specific cylinder and overrides refrigerant return vapor to that cylinder from other coils functioning as evaporators. Solenoid operated valves effect unloading of the compressor during start up and automatically effect removal or inclusion of selected cylinders to the single stage compressor operation. Automatic load responsive control of compressor drive motor speed is effected.

Abstract: A compression module may comprise a hermetic helical screw rotary compressor having injection and ejection ports in addition to discharge and suction ports or may comprise a multiple cylinder, multiple level, reciprocating compressor. The module incorporates a subcooler coil and is connected to an outside air coil, a thermal energy storage coil, a direct solar energy supply coil, one or more inside coils for the space to be conditioned and a hot water coil through common, discharge manifold, suction manifold, liquid drain manifold and liquid feed manifold, by suitable solenoid operated control valves and check valves. The solenoid operated control valves are selectively operated in response to system operating parameters. Seal pots and positive displacement pumps may operate to force liquid refrigerant condensed at intermediate pressure to flow to the receiver which is pressurized at a pressure corresponding to the condensation temperature of the highest pressure condensing coil in the system.

Abstract: A helical screw,expander generator system preferably incorporates a hermetic helical screw expander and induction generator unit with the expander incorporated within a closed loop fluid circuit including an expander boiler upstream of the expander and a condenser downstream with the closed loop circuit carrying an organic working fluid, and the expander boiler receiving heat from a solar or reclaim heat source. The expander carries at least one slide valve for controlling expander capacity. Ejection ports may be carried by additional slide valves for ejecting partially expanded working fluid which is fed to first and second stage heat regenerators to preheat the liquified working fluid as it passes from the condenser to the expander boiler to permit cycle efficiency to approach the theoretical Carnot limits of the system.

Abstract: In a vertical hermetic compressor, an inner cylindrical housing coaxially mounted within a sealed outer enclosure, sealably carries at its lower end, paired helical screw rotors defining with the inner housing a screw compressor compression chamber and supports coaxially with one of the screw rotors and constituting an axial extension thereof the compressor electrical drive motor by longitudinally spaced tapered roller bearings. Oil is bled from the sump and fed to the suction inlet tube to the compressor upstream of the working gas filter. Compressed working fluid is discharged axially downwardly with the lower tapered roller bearing assembly providing a minimal high pressure gap between the screw rotor ends and the stationary end plates. Entrained oil from the discharge passage which extends through the electric motor rotor seeks the suction side of the compressor through the upper of the two tapered roller bearing pack assemblies for controlled continuous lubrication of the upper bearing assembly.

Abstract: A positive displacement compressor, such as a helical screw rotary compressor without capacity control element, is coupled in a refrigeration loop main line between the evaporator and an oil separator and upstream of the condensor. To unload the screw compressor at low evaporator load, any refrigerant discharging from the compressor is bypassed by a line connecting the suction and discharge sides of the screw compressor, and main line connection from the evaporator to the screw compressor is shut off such that the driven, unloaded screw compressor pulls oil from the separator through a restrictor and oil injection port and some refrigerant vapor which passes to the evaporator side through the screw compressor bypass line. As the evaporator pressure increases, the evaporator is connected through a restrictor within the main line to the screw compressor suction.

Abstract: A pair of helical screw rotary hermetic compressor units are connected in parallel across common suction and discharge manifolds. The discharge manifolds open to each unit casing well above the level of accumulated oil within the bottom of the hermetic casings acting as oil sumps. Oil bleed lines are provided for the casings which open to the casing interior at oil bleed ports at the normal level of accumulated oil. The bleed lines are of small diameter and open directly to the discharge manifold at points downstream of the connection between the discharge manifold and the hermetic casing. Excessive accumulation of oil within one of the hermetic compressor casings causes the oil to bleed through its bleed line under a small pressure differential to the discharge manifold for redistribution to the remaining compressors.

Abstract: A defrost control system includes in an electrical control circuit, a number of relay coils and contacts responsive thereto for insuring a delay in termination of the defrost mode and reverse refrigerant flow to the outdoor coil of the heat pump system to delay coil operation as an evaporator, and to effect automatically fan motor reversal and energization to blow air downwardly over the outdoor coil fins to assist gravity in removing the condensate during delay in initiation of heat pump heating cycle, thereby preventing refreezing of condensate on the coil fins.

Abstract: A multi-cylinder reciprocating compressor is automatically staged at low ambient temperature to improve refrigerant volume flow while facilitating subcooler operation and return of vaporized refrigerant from the subcooler to the inlet of the second stage cylinders of the compressor in the two stage mode. A solar evaporator substitutes for the outdoor coil when the solar heated storage tank temperature exceeds that of ambient. During staging mode, the wrist pins of the low side cylinders and the high side cylinder undergo proper load reversals, since intermediate suction pressure is applied to the wrist pin of the high side cylinders.

Abstract: An air source heat pump system includes in a primary refrigeration circuit a hermetic screw compressor and a helical screw rotary expander selectively clutchable to the permanently coupled helical screw compressor and electric induction drive motor. A solar/reclaim evaporator alternately functions as an expander boiler to feed refrigerant vapor to the compressor injection slide valve or to the feed port of the helical rotary screw expander to cause the expander to drive the compressor under compressor load or to drive the electric induction motor as a generator with the compressor unloaded. The solar/reclaim evaporator and expander boiler may be selectively fluid connected to the injection slide valve or to the suction port of the compressor. The hydronic system heating condenser and water chilling evaporator coil may form basic input and rejection heat exchangers to cascaded building zone heat pumps.

Abstract: A helical screw rotary compressor is provided with oppositely oriented slide valves at the suction and discharge sides of the machine to control compressor capacity and balance the closed thread pressure at discharge with discharge line pressure in a main closed loop heat pump refrigeration system. The compressor may be bidirectional if the function of the slide valves is reversed. Additional slide valves carried by the compressor may be employed to vary the injection point of intermediate pressure refrigerant gas to a compressor closed thread and to control flow to and/or from closed threads and a secondary loop for subcooling the main loop refrigerant or for other functions.

Abstract: An axially shiftable slide valve member in a rotary, helical screw compressor carries a port which senses the pressure of the working fluid in the trapped volume just before uncovering of the closed thread to the discharge port and compares that pressure with the line pressure at the discharge port and shifts the slide valve member to balance the pressures and prevent overcompression or undercompression of the compressor. The screw compressor may be provided with two identical but oppositely oriented slide valve members on opposite sides of the intermeshed helical screws with one slide valve member controlling the capacity of the compressor and the other balancing the closed thread pressure at discharge with discharge line pressure. Compressor rotation may be reversed to eliminate the need for a reversing valve where the compressor operates in heat pump or reverse flow defrost refrigeration applications, with the two slide valves trading functions.

Abstract: An axially shiftable slide valve member in a rotary, helical screw compressor carries a port which senses the pressure of the working fluid in the trapped volume just before uncovering of the closed thread to the discharge port and compares that pressure with the line pressure at the discharge port and shifts the slide valve member to balance the pressures and prevent overcompression or undercompression of the compressor. The screw compressor may be provided with two identical but oppositely oriented slide valve members on opposite sides of the intermeshed helical screws with one slide valve member controlling the capacity of the compressor and the other balancing the closed thread pressure at discharge with discharge line pressure. Compressor rotation may be reversed to eliminate the need for a reversing valve where the compressor operates in heat pump or reverse flow defrost refrigeration applications, with the two slide valves trading functions.