An air conditioning system of a vehicle having an internal combustion engine includes a condenser configured to receive refrigerant output by an electric compressor and transfer heat from the refrigerant within the condenser to air passing the condenser. A first evaporator is configured to receive refrigerant from the condenser when a first control valve is open and transfer heat from air passing the first evaporator to the refrigerant within the first evaporator. A first blower is configured to blow air across the first evaporator to a first section of a cabin of the vehicle. A second evaporator is configured to receive refrigerant from the condenser when a second control valve is open and transfer heat from air passing the second evaporator to the refrigerant within the second evaporator. A second blower is configured to blow air across the second evaporator to a second section of the cabin of the vehicle.

A rotary compressor system includes a compressor housing that includes a compressor motor that draws in fluid from a suction side. The fluid is compressed within a compression chamber and discharged through a discharge side. The compression chamber is disposed between the suction side and the discharge side. An overload-protection switch is electrically coupled in series with the compressor motor and is adapted to cut power to the compressor motor responsive to an overload event. A solenoid valve is fluidly coupled between the compression chamber and a location upstream of the suction side and is electrically coupled in series with the overload-protection switch. An interruption of electrical current to the compressor motor also interrupts electrical current to the solenoid valve, which opens the solenoid valve to equalize pressure between the suction side and the discharge side.

The present disclosure is directed to a single compressor HVAC system with hot gas reheat. The system includes a single compressor, a pair of condensers, a reheat heat exchanger, an evaporator, and an expansion device. Within the system, the refrigerant exiting the compressor is separated into two portions. In the cooling mode, the first and second portions of the refrigerant are directed from the compressor through the two condensers in parallel. In the reheat mode, the first portion of the refrigerant is directed through the first condenser, while the second portion of the refrigerant is directed through the reheat heat exchanger. The system also may include a head pressure control device that is designed to maintain the compressor discharge pressure within a desired range by adjusting the condenser fan speed.

The present disclosure is directed to a heating, ventilation, and/or air conditioning (HVAC) system having a refrigerant circuit that includes a compressor, a condenser system with a first set of tubes and a second set of tubes fluidly separate from the first set of tubes within the condenser system, and a valve positioned downstream of the compressor and upstream of the second set of tubes relative to a direction of refrigerant flow through the refrigerant circuit, in which the refrigerant circuit is configured to direct refrigerant through the first set of tubes and through the second set of tubes. The HVAC system further has a pressure switch configured to detect a discharge pressure of the compressor and to instruct the valve to close based on the discharge pressure being below a threshold pressure such that refrigerant flow is blocked through the second set of tubes and refrigerant flow is enabled through the first set of tubes.

A controller in a refrigeration cycle apparatus performs a refrigerant recovery operation when switching an operation mode from a defrosting mode to a heating mode. During the refrigerant recovery operation, by rotating a fan of a blower while monitoring a pressure at a discharge side of the compressor, the controller is configured to perform feedback control to cause a high-pressure side pressure to be close to a high-pressure side target pressure value. During the refrigerant recovery operation, by controlling a driving frequency of the compressor while monitoring a pressure at a suction side of the compressor, the controller is configured to perform feedback control to cause a low-pressure side pressure to be close to a low-pressure side target pressure value.

Apparatus for staged startup of air-cooled low charged packaged ammonia refrigeration system includes motorized valves on condenser coil inlets, a main compressor discharge motorized valve, a bypass pressure regulator valve in the main compressor piping, check valves on the condenser outlets and speed control of the condenser fans. The condenser inlet motorized valves provide precise control of gas feed to the condensers, so pressure can build without collapsing the oil pressure. The condenser coil outlet contains inline check valves to prevent liquid backflow when a coil is isolated. The compressor discharge line contains a single motorized valve for regulating discharge pressure at start-up. The motorized valve in the compressor discharge piping also includes a bypass with a mechanical pressure regulator to allow precise regulation at the minimum discharge pressure. Once discharge pressure rises above the minimum setpoint, the condenser inlet solenoid coils will open one at a time. The discharge pressure regulating motorized valve will simultaneously regulate the discharge pressure until the condenser coil has warmed up enough to maintain discharge pressure.

An air-conditioning apparatus that includes a compressor, a flow switching device, an outdoor heat exchange unit, an expansion section and an indoor heat exchanger, which are connected by pipes, in which the outdoor heat exchange unit includes a first outdoor heat exchanger, a first flow rate control device, a second outdoor heat exchanger, a second flow rate control device, a bypass pipe, the second outdoor heat exchanger, the second flow rate control device, a third flow rate control device, and a flow control device.

An air conditioning system of a vehicle having an internal combustion engine includes a condenser configured to receive refrigerant output by an electric compressor and transfer heat from the refrigerant within the condenser to air passing the condenser. A first evaporator is configured to receive refrigerant from the condenser when a first control valve is open and transfer heat from air passing the first evaporator to the refrigerant within the first evaporator. A first blower is configured to blow air across the first evaporator to a first section of a cabin of the vehicle. A second evaporator is configured to receive refrigerant from the condenser when a second control valve is open and transfer heat from air passing the second evaporator to the refrigerant within the second evaporator. A second blower is configured to blow air across the second evaporator to a second section of the cabin of the vehicle.

A heat pump system for conditioning regeneration air from a space is provided. The heat pump system is operable in a winter mode and/or a summer mode, and may be selectively operated in a defrost mode or cycle. During a defrost mode, hot refrigerant may be used to directly and sequentially defrost the regeneration air heat exchanger. A compressor may be configured to be overdriven during a defrost cycle.

Thermal energy systems for managing, distribution and recovery of thermal energy. A single-pipe loop circulating a two-phase refrigerant is provided. The single-pipe loop is spread through the entire system and interconnects a plurality of local heat exchange stations, each having different thermal energy loads. A central circulation mechanism (CCM) is also provided for circulating the refrigerant for distribution of thermal energy within the system.