A METHOD FOR CONTROLLING A FLOW OF REFRIGERANT TO A MULTI- TUBE EVAPORATOR

摘要

A method for controlling a flow of refrigerant to an evaporator arranged in a vapour compression system is disclosed. The vapour compression system comprises the evaporator, a compressor, a condenser, and an expansion device arranged in a refrigerant flow path. The evaporator comprises at least two evaporator tubes arranged fluidly in parallel, and a header being fluidIy connected between the expansion device and the evaporator tubes. The method comprises the steps of alternatingly allowing and preventing a flow of mixed phase refrigerant into the header. The step of allowing a flow of mixed phase refrigerant into the header is performed in such a manner that a pressure level in the header is increased significantly and abruptly. Thereby the liquid part and the gaseous part of the mixed phase refrigerant are distributed substantially homogeneously in the header. Thereby the liquid part of the refrigerant is distributed in a substantially uniform manner among the evaporator tubes, and the same filling degree is obtained in the tubes. The potential refrigeration capacity of the evaporator can be utilised to a greater extent without risking that liquid refrigerant passes the evaporator.