Integrated electronic refrigerant management system
AssigneeCarrier Corporation
InventorsThomas Edward Brendel, John Robert Reason, Douglas Herbert Morse, L. Thomas Lane, Mead Robert Rusert
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Abstract
A process and method for monitoring and selectively controlling the capacity and power demand within a transport unit is disclosed. Specifically, the present invention teaches the combined controls of an electronic suction modulation valve, and electronic expansion valve, and/or an electronic hot gas valve in communication with a microcontroller and a number of sensors in order to monitor and control power consumption and capacity, preferably without the use or presence of compressor unloaders, mechanical throttling devices, or other mechanical power control devices.
Claims9
A process for improving the capacity of a transport refrigeration system, said process comprising the steps of:
- i monitoring evaporator outlet pressure and evaporator outlet temperature;
- ii comparing said evaporator outlet temperature and evaporator outlet pressure readings to a predetermined superheat limit stored in a controller memory;
- and
- iii selectively operating an electronic expansion valve in response to a evaporator outlet pressure and outlet temperature readings in excess of said predetermined limit.
A process for eliminating the occurrence of “top freezing” events within a transport refrigeration system, said process comprising the steps of:
- i sensing air temperature of air returning to an evaporator;
- ii comparing said return air temperature to a preselected limit;
- and
- iii selectively bypassing refrigerant around a condenser through an electronic hot gas valve to an evaporator, thus reducing the cooling capacity of the transport refrigeration system.
A process for controlling the power consumption of a transport refrigeration system in the absence of loading or unloading compressor cylinders, said process comprising the steps of:
- i monitoring discharge pressure of a compressor within the transport refrigeration system;
- ii comparing said compressor discharge pressure to a desired, preselected compressor discharge pressure limit;
- and
- iii selectively actuating an electronic suction modulation valve when said compressor discharge pressure exceeds said compressor discharge pressure limit, thereby restricting a refrigerant mass flow within the refrigeration system and to decreasing the compressor discharge pressure of said transport refrigeration system.
A process for optimizing capacity in a refrigeration unit under controlled, power limitation conditions, said process comprising the steps of:
- i monitoring discharge pressure of a compressor and ambient air temperature of the refrigeration unit;
- ii determining a desired compressor discharge pressure limit;
- iii comparing said compressor discharge pressure to said desired compressor discharge pressure limit;
- and
- iv selectively increasing a desired superheat setting when said compressor discharge pressure exceeds said compressor pressure discharge limit, thereby decreasing the a refrigerant mass flow within the refrigeration unit and decreasing power consumed by said refrigeration unit.
Dependencies are inferred from the claim text.