Method and arrangement for defrosting a vapor compression system

Abstract

Method for defrosting of a heat exchanger (evaporator) in a vapor compression system including, beyond a heat exchanger (evaporator) (3) to be defrosted, at least a compressor (1), a second heat exchanger (condenser/heat rejecter) (2) and an expansion device (6) connected by conduits in an operable manner to form an integral closed circuit. The heat exchanger (3) to be defrosted is subjected to essentially the same pressure as the compressor's (1) discharge pressure whereby the heat exchanger (3) is defrosted as the high-pressure discharge gas from the compressor (1) flows through to the heat exchanger, giving off heat to the said heat exchanger (3). An arrangement is characterized in that, in the circuit, in connection with the expansion device (6) is provided a first bypass loop (23) with a first valve (16′), and that a pressure reducing device (6′) is provided in a second bypass loop in conjunction with a second valve (16′″) disposed after the heat exchanger (3) being defrosted, whereby the first value (16′) is open and the second valve (16′″) is closed when defrosting takes place.

Dependencies are inferred from the claim text.