A refrigerant loop of a vapor injection heat pump includes a compressor, first and second expansion valves, and first and second separator valves. The separator valves allow an entire refrigerant flow to pass therethrough or operate to separate vapor and liquid components of expanded refrigerant and inject the vapor component into a suction port of the compressor. Vapor injection occurs in both heating and cooling modes of operation and may depend upon an ambient condition (e.g., high or low ambient temperatures). An accumulator receives an output refrigerant of the heat exchangers dependent upon the mode and directs a vapor component into another suction port of the compressor. A control module controls at least the first and second expansion valves and first and second separator valves dependent upon the mode of operation which include, among others, heating, cooling, and dehumidification and re-heating.

Methods and systems for providing control of a heat pump of a motor vehicle are presented. In one operating mode, speed of a heat pump compressor is controlled responsive to an outlet pressure of the heat pump compressor. In a second operating mode, speed of the heat pump compressor is controlled responsive to a pressure ratio between an inlet and an outlet of the heat pump compressor.

A power management method used for power distribution in a transportation refrigeration unit. The power management method includes calculating engine power according to engine operating parameters; calculating power generator real-time input power according to power generator excitation current; calculating available power based on the power generator real-time input power and the engine power; and managing power distributed to a compressor based on the available power. The present invention further relates to a power management system. The power management method and system have the advantages of simplicity, reliability, stable operation and the like, the power generator real-time input power can be calculated according to the power generator excitation current, thus more power can be provided to the compressor on the premise that the power supply to power generator loads is guaranteed, and the operating efficiency of the transportation refrigeration unit is improved.

A vehicle heating, ventilating, and air conditioning (HVAC) system can be configured to reduce and/or prevent condensation build up on one or more elements of the system. Subsequent to a power state of the vehicle being switched from an active state to an inactive state, a fresh mode air source can be selected as an intake for a blower. It can be determined whether an ambient temperature is greater than or equal to a predetermined temperature. It can then be determined whether the compressor was in operation prior to the vehicle having been switched from the active state to the inactive state. It can be determined whether a temperature of an evaporator of the HVAC system is rising. If it is determined that the ambient temperature is greater than or equal to the predetermined temperature value, that the compressor was in operation prior to the vehicle having been switched from the active state tot eh inactive state, and that the temperature of the evaporator is rising, a blower can be activated to blow air from the fresh mode air source across the evaporator.

The present disclosure relates to a method of controlling a compressor, and may include: pilot driving which drives a compressor of an air conditioner by receiving a start signal; determining whether oil is short which compares the oil amount of the compressor, driven in the pilot driving, with a predetermined reference oil amount; normal driving which maintains the driving of the compressor when it is determined that the oil amount is the reference oil amount or more; and stopping which stops the driving of the compressor when it is determined that the oil amount is smaller than the reference oil amount. Accordingly, by stopping the compressor when the oil is short, it is possible to prevent damage to the compressor.

A method of feedthrough and overcurrent protection of a sealed compressor used in a transport climate control system (“TCCS”) is provided. The TCCS includes a climate control circuit with a sealed compressor. The sealed compressor includes an outer housing and an electrical motor within the outer housing. The method includes operating the sealed compressor to compress a working fluid by supplying electrical power to the electric motor of the sealed compressor via a sealed electrical feedthrough in the outer housing of the sealed compressor. The method also includes detecting an operating parameter of the sealed electrical feedthrough, and determining whether the sealed electrical feedthrough is in a melting condition based on the detected operating parameter. Also, the method includes adjusting operation of the climate control circuit upon determining that the sealed electrical feedthrough is in the melting condition until the sealed electrical feedthrough is no longer in the melting condition.

A method of controlling a transport refrigeration system including a refrigeration unit including a compressor, and a refrigerated compartment operably coupled to the refrigeration unit, and the transport refrigeration system is operable in a standby mode in which the transport refrigeration system is connected to and powered by a mains power source, the method including providing a first compressor speed, wherein the first compressor speed is less than a maximum speed of the compressor of the refrigeration unit; determining when the transport refrigeration system is being operated in the standby mode; determining whether a current time is within a first time period; and when it is determined that the transport refrigeration system is being operated in the standby mode, and when it is determined that the current time is within the first time period: operating the compressor of the refrigeration unit in accordance with the first compressor speed.

A transport refrigeration unit system (26) for cooling a trailer compartment (24) is provided. The transport refrigeration unit system (26) includes an engine for controlling a cooling rate capacity, the engine operable at a nominal high speed and a nominal low speed. Also included is a controller (50) in operative communication with the engine to control an engine speed of the engine. Further included is a user interface (52) in operative communication with the controller (50), the user interface (52) providing a high capacity cooling mode to a user, wherein initiation of the high capacity cooling mode includes the engine operating at a speed greater than the nominal high speed to result in a high capacity cooling rate.

There is disclosed a transport refrigeration system comprising an electronically governed engine that drives a refrigeration circuit of the system. The engine control unit is configured to operate the engine in a droop mode of operation, in which the engine speed increases with decreasing engine loads from the refrigeration circuit, so as to maximise the cooling capacity of the system at low engine load conditions.

A control method of an air conditioning system for compressor protection includes, when an air conditioner turn-on request is present, determining, by a controller, whether a compressor operating condition is satisfied from a refrigerant state of an air conditioner, when the compressor operating condition is determined as being satisfied, determining, by the controller, whether the vehicle is in a state of being unattended for a long period of time using information collected from a vehicle, when the vehicle is determined as being in a state of being unattended for a long period of time, performing, by the controller, pre-run control for operating the compressor in a predetermined minimum load condition; and when a pre-run operating time for which the compressor is operated in a minimum load condition reaches a predetermined pre-run holding time, interrupting, by the controller, the pre-run control with respect to the compressor.