Carrier Corporation

Raymond L Senf, Jr

Gilbert B Hofsdal

John Robert Reason

Douglas Auyer

Alan D Abbott

William C Silliman

Michael Stockbridge

Paul Valentine Weyna

Donald B Hotaling

Eliot W Dudley

Florian Beaufrere

Wenhua Li

Martin O Johnsen

Mark S Rogers

Stephen Kenney

Herbert J Call

Swee Meng Ng

A method of operating a transport refrigeration system having a plurality of inverters configured to power a refrigeration unit includes placing a first inverter of the plurality of inverters in an active state; monitoring a load on the first inverter; comparing the load on the first inverter to an upper threshold; placing a second inverter of the plurality of inverters in an active state upon the load on the first inverter being greater than the upper threshold.

Transport refrigeration system with paralleled inverters

A method of operating a refrigeration system () includes operating the refrigeration system in refrigeration mode. A current access condition into a refrigerated cargo space () is detected. At least one heat exchanger () in the refrigerated cargo space () is directed into a defrost mode during the current access condition. The refrigeration system () is directed into a refrigeration mode when the current access condition is no longer detected.

Method of defrosting a refrigeration system

A method of operating a refrigeration system is provided. The method includes activating an evaporator heater, monitoring a pressure differential within the refrigeration system, when the pressure differential reaches a predetermined value, deactivating the evaporator heater, and activating one or more evaporator fans, after deactivating the evaporator heater, to cause a thermostatic expansion valve to open.

Thermostatic expansion valves and methods of control

Disclosed is a method of operating a trailer refrigeration unit of a refrigerated trailer system comprising setting a cargo hold set point temperature through a user interface; urging an airflow along a flowpath from a return air inlet port, through an evaporator of the trailer refrigeration unit, and to a supply air outlet port of the trailer refrigeration unit; monitoring a return air temperature of the airflow flowing through the return air inlet port; monitoring a supply air temperature of the airflow flowing through the supply air outlet port; heating the airflow flowing through the supply air outlet port when the return air temperature is less than the cargo hold set point temperature; and stopping heating of the airflow flowing to the supply air outlet port when the return air temperature is less than the cargo hold set point temperature and the supply air temperature reaches a threshold.

Trailer refrigeration unit and methods for limiting the supply air temperature thereof

A method of operating a refrigeration system. The method includes operating a multi-temperature refrigeration system that has a plurality of heat absorption heat exchangers in a single temperature mode. A number of the plurality of heat absorption heat exchangers are determined that require defrosting a single heat absorption heat exchanger is directed into a different operational state when the number of heat absorption heat exchangers that require defrosting is equal to one. E of the plurality of heat absorption heat exchangers is directed into a defrost mode when the number of heat absorption heat exchangers that requires defrosting is more than one.

Method of defrosting a multiple heat absorption heat exchanger refrigeration system

A method of operating a refrigeration system is provided. The method includes activating an evaporator heater (), monitoring a pressure differential within the refrigeration system (), when the pressure differential reaches a predetermined value (), deactivating the evaporator heater (), and activating one or more evaporator fans (), after deactivating the evaporator heater, to cause a thermostatic expansion valve to open.

A method of operating a refrigeration system includes initiating a compressor shutdown operation, determining a difference in a saturation temperature at a port of a compressor of the refrigeration system and an ambient temperature and comparing the difference in the saturation temperature and ambient temperature with a threshold. If the difference in the saturation temperature and ambient temperature is less than or equal to the threshold, a pump down operation is performed and if the difference in the saturation temperature and ambient temperature exceeds the threshold, a compressor shutdown operation is completed.

Method of control for economizer of transport refrigeration units

Systems and methods of operating a refrigeration system including initiating a compressor shutdown operation (), recording shutdown conditions (), calculating one or more restart characteristics based on the recorded shutdown conditions (), comparing the calculated restart characteristics with one or more compressor restart safety limits (), when the calculated restart characteristics do not satisfy the restart safety limits, performing a temperature modulation pump down operation (), and when the calculated restart characteristics satisfy the restart safety limits, completing the compressor shutdown operation ().

Methods of control for transport refrigeration units

A transportation refrigeration system includes a refrigeration circuit that includes a compressor, a condenser, a first expansion device upstream of a first heat exchanger and a second expansion device upstream of a second heat exchanger. The first heat exchanger includes a first cooling capacity that is different from a second cooling capacity of the second heat exchanger.

Transportation refrigeration system with unequal sized heat exchangers

A method of managing a compressor start operation, the method includes controlling a valve disposed upstream of a compressor to lower a saturated suction temperature of a refrigerant to be below an ambient temperature while starting the compressor.

Method of managing compressor start for transport refrigeration system

A method of operating a transport refrigeration system comprises: controlling, using a controller (), a plurality of components of the refrigeration system and monitoring, using the controller, a plurality of operating parameters of the refrigeration system. The controlling comprises operating at least one of a prime mover (), heater (), and electric generation device (). The operating parameters comprise at least one of a speed of the prime mover and a voltage of the electric generation device. The method comprises detecting, using the controller, when at least one of a heating mode and a defrost mode is required; activating, using the controller, the heater when at least one of the heating mode and the defrost mode is required; comparing, using the controller, the voltage of the electric generation device to a selected voltage; and controlling, using the controller, the speed of the prime mover in response to the voltage of the electric generation device.

Intelligent voltage control for electric heat and defrost in transport refrigeration system

A method of detecting airflow blockage of a transport refrigeration system including the steps of: activating a heater powered by an electric generation device; measuring an output voltage of the electric generation device; determining a predicted heat output of the heater in response to the output voltage; determining a predicted temperature rise across the heater in response to the predicted heat output; detecting a measured temperature rise across the heater; and determining an airflow reduction percentage in response to the predicted temperature rise across the heater and the measured temperature rise across the heater.

Method for determining reduced airflow in transport refrigeration system

A transportation refrigeration unit includes an evaporatorcirculating a flow of refrigerant therethrough to cool a flow of supply air flowing over the evaporator. Two compressorsare in fluid communication with the evaporator to compress the flow of refrigerant and are configured and connected to operate in parallel with one another. A condenseris in fluid communication with the evaporator and the two compressors. An economizer heat exchangerand a suction line heat exchangerare provided.

Transportation refrigeration unit with multiple compressors

A multi-compartment transport refrigeration system includes a heat rejecting heat exchanger downstream of a compressor discharge port; a first evaporator expansion device downstream of the heat rejecting heat exchanger; a first evaporator having an first evaporator inlet coupled to the first evaporator expansion device and a first evaporator outlet coupled to the compressor inlet path, the first evaporator for cooling a first compartment; a second evaporator expansion device downstream of the heat rejecting heat exchanger; a second evaporator having a second evaporator inlet coupled to the second evaporator expansion device and a second evaporator outlet coupled to the compressor inlet path, the second evaporator for cooling a second compartment; and a first evaporator outlet isolation valve positioned in an outlet of the first evaporator, the first evaporator outlet isolation valve to prevent migration of refrigerant from the second evaporator outlet to the first evaporator outlet.

Multi-compartment transport refrigeration system with evaporator isolation valve

A multi-compartment transport refrigeration system () includes a first evaporator () having an first evaporator inlet coupled to a first evaporator expansion device () and a first evaporator outlet coupled to a compressor inlet path, the first evaporator for cooling a first compartment of a container at a first temperature; a second evaporator (having a second evaporator inlet coupled to a second evaporator expansion device () and a second evaporator outlet coupled to the compressor inlet path, the second evaporator for cooling a second compartment of the container at a second temperature greater than the first temperature; and a controller () for controlling the first evaporator expansion device in response to a first superheat setpoint and controlling the second evaporator expansion device in response to a second superheat setpoint, the controller adjusting the second superheat setpoint in response to the second temperature and the first temperature.

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Central Square, NY, United States of America

Raymond L Senf, Jr