METHOD OF CONTROLLING ONE OR MORE FANS OF A HEAT REJECTING HEAT EXCHANGER

摘要

A method of controlling a fan of a vapour compression system is disclosed. The vapour compression system comprises a compressor, a heat rejecting heat exchanger, e.g. in the form of a gas cooler or a condenser, an expansion device and an evaporator arranged in a refrigerant circuit. The fan is arranged to provide a secondary fluid flow across the heat rejecting heat exchanger, e.g. in the form of an air flow. The method comprises the steps of establishing a temperature, T1, of refrigerant leaving the heat rejecting heat exchanger, establishing a temperature, T2, of ambient air of the heat rejecting heat exchanger, and deriving a temperature difference, ΔT=T1-T2, between the temperature (T1) of refrigerant leaving the heat rejecting heat exchanger and the temperature (T2) of ambient air of the heat rejecting heat exchanger. The temperature difference, ΔT, is compared to a first threshold value and to a second threshold value, the second threshold value being smaller than or equal to the first threshold value, and the rotational speed of the fan is controlled on the basis of the comparing step. The method allows the electrical energy consumption of the fan to be reduced without risking instability of the vapour compression system.

主权项

1. A method of controlling a fan of a vapour compression system, the vapour compression system comprising a compressor, a heat rejecting heat exchanger, an expansion device and an evaporator arranged in a refrigerant circuit, said fan being arranged to provide a secondary fluid flow across the heat rejecting heat exchanger, the method comprising the steps of:
establishing a temperature, T1, of refrigerant leaving the heat rejecting heat exchanger, establishing a temperature, T2, of ambient air of the heat rejecting heat exchanger, deriving a temperature difference, ΔT=T1-T2, between the temperature (T1) of refrigerant leaving the heat rejecting heat exchanger and the temperature (T2) of ambient air of the heat rejecting heat exchanger, comparing the temperature difference, ΔT, to a first threshold value and to a second threshold value, the second threshold value being smaller than or equal to the first threshold value, and controlling the rotational speed of the fan on the basis of the comparing step.