Patent ID: 7665321

Claim:
A method for controlling evaporators in refrigeration plants, which refrigeration plants comprise a refrigerant circuit with a compressor, a liquefier, an expansion valve, an evaporator, and an internal heat exchanger connected downstream of the evaporator, wherein the evaporation process of the refrigerant from at or near a supercooled liquid state to a saturated state occurs within the evaporator and the evaporation process from a saturated state to a superheated gas state occurs within the internal heat exchanger and wherein the onset of the evaporation process controlled, whereby the refrigerant is at or near a supercooled state at the inlet of the evaporator and the evaporation pressure of the refrigerant at the inlet of the evaporator is measured and used as a first control variable, whereby the refrigerant is in a supercooled liquid state upstream of the expansion valve and the temperature upstream of the expansion valve is measured and used as second control variable for the control of the expansion valve, so that in this way the start of evaporation is defined and controlled.