An air conditioning refrigerant circuit (6) includes an engine-driven compressor (7) and an electric compressor (11), which are arranged in parallel. When the engine is running, the engine-driven compressor (7) is used. When the engine stops, e.g., when idling stops, the electric compressor (11) is used. At the startup of the engine by a manual operation such as ignition by a key, the engine-driven compressor (7) is kept at rest and instead, the electric compressor (11) is operated for a predetermined time. After the predetermined time, the engine-driven compressor (7) is operated. In this way, the oil recovery to the electric compressor is promoted.

A method is disclosed for generating and distributing electric power for localized use. The method entails providing an enclosed building having an air conditioning and ventilation unit for supplying cooled air within the building, the unit including a closed loop circuit configured to operate a closed loop refrigeration cycle, including a compressor operable to compress a working fluid of the closed loop circuit. The method further includes engaging an internal combustion engine with the compressor and operating the internal combustion engine to drive the compressor, thereby transferring energy to the refrigeration cycle. The method may also involve engaging an electric motor with the compressor and operating the electric motor to drive the compressor, thereby transferring energy to the refrigeration cycle.

A transport refrigeration system (TRS) and method of controlling temperature using an unloader manifold. The TRS includes a heat transfer circuit, the heat transfer circuit includes a compressor with a first cylinder bank and a second cylinder bank, and an unloader manifold with a first end connected to the first and second cylinder bank and a second end connected to a hot gas line in the heat transfer circuit. The first and second cylinder banks and the hot gas line are in fluid communication via the unloader manifold such that a heat transfer fluid can flow therethrough. The TRS further includes an unloader discharge controller to unload, via the unloader manifold, heat transfer fluid from the first cylinder bank to a first discharge level.

A bi-fuel refrigeration system and method of retrofitting a refrigeration system for the same. The system includes an engine in energy supplying relation to a refrigeration unit, said engine running off a constant predetermined amount of gaseous fuel and a variable amount of distillate fuel. An electronic control unit generates control signals to dictate the ratio of gaseous to distillate fuel is used by the engine. An actuator is structured to provide isochronous control of the system, and is accordingly disposed in flow adjusting relation to the distillate fuel intake to variably adjust the amount of distillate fuel injected into the engine. The method of retrofitting includes at least inserting a gaseous fuel supply and mixer into the air supply line, inserting an electronic control unit for isochronous control of the system, and inserting an actuator for isochronous control of the amount of distillate fuel used in the system.

A heat pump is provided with a compressor; an oil separator provided on a discharge path of the compressor; an accumulator connected to the compressor via a suction path; and a bypass circuit configured to supply a gas refrigerant separated by the oil separator. The bypass circuit is connected to the suction path.

A method and apparatus controls a recirculation position of a return vent in an HVAC system for a vehicle with a compressor driven by a start/stop engine. A partial recirculation position is set according to a basic recirculation strategy while the engine is operating. An auto stop event is entered at a time with the compressor operating. A full recirculation position is set during the stop event by an HVAC controller if a plurality of low fogging probability indicators are true. The low fogging probability indicators include a sensed ambient temperature being above a predetermined temperature, a sensed state of a windshield wiper being an off state, and a sensed sunload being above a predetermined sunload. The return vent is set at other than the full recirculation position by the HVAC controller according to the basic recirculation strategy if the low fogging probability indicators are not true.

An apparatus includes a chamber, a first heat exchanger, an adapter, and a second heat exchanger. The first heat exchanger includes a cold finger positioned within the chamber. The second heat exchanger is positioned around an adapter and within the chamber. The second heat exchanger is a counter flow heat exchanger to precool refrigerant entering a Joule-Thomson valve. The adapter is positioned between the cold finger and the second heat exchanger. The adapter transfers heat from a thermal load to both the cold finger and the refrigerant emitted from the Joule-Thomson valve.

A method is disclosed for generating and distributing electric power for localized use. The method entails providing an enclosed building having an air conditioning and ventilation unit for supplying cooled air within the building, the unit including a closed loop circuit configured to operate a closed loop refrigeration cycle, including a compressor operable to compress a working fluid of the closed loop circuit. The method further includes engaging an internal combustion engine with the compressor and operating the internal combustion engine to drive the compressor, thereby transferring energy to the refrigeration cycle. The method may also involve engaging an electric motor with the compressor and operating the electric motor to drive the compressor, thereby transferring energy to the refrigeration cycle.

A body of an ejector includes a diffuser passage, in which an ejection refrigerant jetted from a nozzle passage and a suction refrigerant drawn from a suction passage are mixed together and pressurized by arranging a passage formation member, and a gas-liquid separation space, in which the refrigerant flowing out of the diffuser passage is separated into gas and liquid by the action of a centrifugal force. An inlet part of an oil return passage that is open in the gas-liquid separation space is arranged at a position closer to an outer peripheral side than to an axis center of the passage formation member.

An exhaust heat reclaim system may include a diverter valve selectively connected in fluid communication to an exhaust vent tube and an exhaust delivery tube and configured to selectively divert hot exhaust fluid discharged from an exhaust of a power generation device to at least one of the exhaust vent tube and the exhaust delivery tube. The exhaust heat reclaim system may be a component of an HVAC system and be configured to discharge hot exhaust fluid onto a heat exchanger of the HVAC system, where the heat exchanger may be configured to promote heat transfer between the hot exhaust fluid and a refrigerant flowing through the heat exchanger of the HVAC system.