Expansion valve control system and method for air conditioning apparatus

摘要

A method of reducing a cyclical loss coefficient of an HVAC system efficiency rating of an HVAC system includes operating the HVAC system using a recorded electronic expansion valve position of an electronic expansion valve of the HVAC system, discontinuing operation of the HVAC system, and resuming operation of the HVAC system using an electronic expansion valve position that allows greater refrigerant mass flow through the expansion valve as compared to the recorded electronic expansion valve position.

主权项

1. A method of reducing a cyclical loss coefficient of an HVAC system efficiency rating of an HVAC system, comprising:
operating the HVAC system and recording a recorded electronic expansion valve position of an electronic expansion valve of the HVAC system; discontinuing operation of the HVAC system; resuming operation of the HVAC system using an electronic expansion valve position that allows greater refrigerant mass flow through the expansion valve as compared to the recorded electronic expansion valve position; after resuming operation of the HVAC system and prior to any later discontinuation of operation of the HVAC system, operating the HVAC system according to an open-loop profile of electronic expansion valve positions during a first phase of control, wherein each of a measured refrigerant gas temperature and a measured evaporator temperature are disregarded during the first phase of control; after operating the HVAC system during the first phase of control and prior to any later discontinuation of operation of the HVAC system, operating the HVAC system during a second phase of control during which the HVAC system is controlled as a combination of (1) the open-loop profile of electronic expansion valve positions and (2) an evaporator temperature based control function as a function of the measured evaporator temperature, wherein the measured refrigerant gas temperature is disregarded during the second phase of control; and after operating the HVAC system during the second phase of control and prior to any later discontinuation of operation of the HVAC system, operating the HVAC system during a third phase of control during which the HVAC system is controlled as a combination of at least (1) the evaporator temperature based control function and (2) a superheat based control function as a function of the measured evaporator temperature and the measured refrigerant gas temperature.