REFRIGERATOR CONTROL SYSTEM AND METHOD

摘要

A control system for operating a refrigerator appliance is provided. The refrigerator has a variable damper, a variable speed fan, and a variable speed compressor. The damper position, evaporator fan speed, and compressor speed are determined through interacting feedback control loops based on the set point temperatures for the fresh food and freezer compartments as well as the measured temperatures in such compartments. The adjustment of these actuators can eliminate large temperature fluctuations and discontinuities in the air flow and improve the thermal performance and energy efficiency of the refrigerator.

主权项

1. A method of operating a refrigerator appliance that includes a fresh food compartment, a freezer compartment, an evaporator, a variable speed evaporator fan for moving air over the evaporator, a variable damper for controlling the flow of air from the freezer compartment to the fresh food compartment, and a variable speed compressor, the method comprising the steps of:
providing a set point temperature, FF SP, for the fresh food compartment; providing a set point temperature, FZ SP, for the freezer compartment; measuring FF THERM, the temperature of the fresh food compartment; measuring FZ THERM, the temperature of the freezer compartment; determining FF ERR, the fresh food compartment temperature error, using FF SP and FF THERM; determining FZ ERR, the freezer food compartment temperature error, using FZ SP and FZ THERM; using FF ERR to determine the fresh food compartment demand for cold air, qFF; using FZ ERR to determine the freezer compartment demand for cold air, qFZ; setting the speed of the evaporator fan based on qFF+qFZ, the sum of the fresh food compartment demand for cold air and the freezer compartment demand for cold air; setting the position of the damper based on qFF/(qFF+qFZ), the fraction of the total demand for cold air of the fresh food compartment; and, setting the speed of the compressor based on a combination of FF ERR and FZ ERR.