Abstract: A transport climate control system for providing climate control to a climate controlled space of a transport unit. The transport climate control circuit includes a compressor, an evaporator and at least two fans. The transport climate control circuit also includes a controller for controlling the transport climate control circuit and for defrosting the evaporator coil. When a defrost event is triggered, the controller instructs the transport climate control circuit to supply heat to or around one section of the evaporator coil, and independently controls each of the at least two fans to move the air around the evaporator coil in a controlled direction so that heat from the one section of the evaporator coil is used to convectively heat the inlet of the evaporator coil.

Abstract: A transport climate control system for providing climate control to a climate controlled space of a transport unit. The transport climate control circuit includes a compressor, an evaporator and at least two fans. The transport climate control circuit also includes a controller for controlling the transport climate control circuit and for defrosting the evaporator coil. When a defrost event is triggered, the controller instructs the transport climate control circuit to supply heat to or around one section of the evaporator coil, and independently controls each of the at least two fans to move the air around the evaporator coil in a controlled direction so that heat from the one section of the evaporator coil is used to convectively heat the inlet of the evaporator coil.

Abstract: A refrigeration unit includes an engine, a motor capable of producing a similar power output as the engine, and a compressor driven by one of the engine and the motor. The compressor includes a suction inlet and a discharge outlet. The refrigeration unit also includes a condenser in fluid communication with the discharge outlet through which pressurized, gaseous refrigerant is condensed, an evaporator in fluid communication with the condenser to receive liquid refrigerant and return gaseous refrigerant to the suction inlet, a passageway having a first end in fluid communication with an outlet of the condenser, and a second end in fluid communication with the suction inlet, and a purge valve defining at least a portion of the passageway between the first and second ends. The purge valve is operable to selectively divert liquid refrigerant from the condenser to the suction inlet to increase the pressure in the suction inlet.

Abstract: A refrigeration unit includes an engine, a motor capable of producing a similar power output as the engine, and a compressor driven by one of the engine and the motor. The compressor includes a suction inlet and a discharge outlet. The refrigeration unit also includes a condenser in fluid communication with the discharge outlet through which pressurized, gaseous refrigerant is condensed, an evaporator in fluid communication with the condenser to receive liquid refrigerant and return gaseous refrigerant to the suction inlet, a passageway having a first end in fluid communication with an outlet of the condenser, and a second end in fluid communication with the suction inlet, and a purge valve defining at least a portion of the passageway between the first and second ends. The purge valve is operable to selectively divert liquid refrigerant from the condenser to the suction inlet to increase the pressure in the suction inlet.

Abstract: An environmentally controlled shipping container including a storage space and a refrigeration system that includes a prime mover, a compressor driven by the prime mover and providing a flow of refrigerant, a condenser that receives the flow of refrigerant from the compressor, an evaporator in heat exchange relation with the storage space to remove heat from air supplied to the storage space. A controller operates the refrigeration system in one of a continuous mode wherein the prime mover operates continuously, a standard start/stop mode wherein the prime mover operates intermittently such that while the prime mover is operating in the standard start/stop mode the compressor provides a maximum flow of refrigerant, and a modulated start/stop mode wherein the prime mover operates intermittently such that while the prime mover is operating in the modulated start/stop mode the operating parameters of the refrigeration system may be modulated.

Abstract: A mobile refrigeration system that includes an engine that is operable at a first speed greater than zero and a second speed greater than zero. A compressor is operable in response to the engine at a first speed and a second speed. The system also includes an evaporator, a first temperature sensor positioned to measure a first temperature, and a second temperature sensor positioned to measure a second temperature. A controller is operable to transition the engine between the first speed and the second speed in response to the first temperature exceeding a first predetermined value and the second temperature falling below a second predetermined value.

Abstract: A mobile refrigeration system that includes an engine that is operable at a first speed greater than zero and a second speed greater than zero. A compressor is operable in response to the engine at a first speed and a second speed. The system also includes an evaporator, a first temperature sensor positioned to measure a first temperature, and a second temperature sensor positioned to measure a second temperature. A controller is operable to transition the engine between the first speed and the second speed in response to the first temperature exceeding a first predetermined value and the second temperature falling below a second predetermined value.

Abstract: A method of controlling a heating cycle of a refrigeration system is provided that includes a refrigerant circuit. The refrigerant circuit includes a compressor having a suction port and an outlet having a discharge port with a hot gas compressor discharge line, a condenser for condensing the refrigerant, an evaporator for evaporating the refrigerant and an expansion valve. The method includes using refrigerant from the hot gas compressor discharge line to heat the evaporator during a heating cycle, detecting periodically a discharge superheat of the refrigerant leaving the outlet of the compressor, producing a control signal representing a difference between the detected discharge superheat and a minimum discharge superheat setpoint, adjusting the flow rate of the refrigerant to the suction port of the compressor according to the control signal so as to maintain the discharge superheat of the refrigerant at the outlet of the compressor substantially at the minimum discharge superheat setpoint.

Abstract: A mobile refrigeration system that includes an engine that is operable at a first speed greater than zero and a second speed greater than zero. A compressor is operable in response to the engine at a first speed and a second speed. The system also includes an evaporator, a first temperature sensor positioned to measure a first temperature, and a second temperature sensor positioned to measure a second temperature. A controller is operable to transition the engine between the first speed and the second speed in response to the first temperature exceeding a first predetermined value and the second temperature falling below a second predetermined value.