Apparatus and method for carrying out a vapour refrigeration process

Abstract

The present invention relates to an apparatus and to a method for carrying out a vapour refrigeration process. The apparatus has a motor-operated main compressor which is equipped to suck-in a mass flow of a fluid serving as a refrigerant which is at evaporating pressure level and to compress this mass flow to a high pressure level, and also a high-pressure heat exchanger which is equipped to cool the mass flow of the fluid at a high pressure level, to increase a density and to reduce a temperature of the fluid. Also provided is an expander which is equipped to expand the mass flow of the fluid coming from the high pressure heat exchanger to evaporating pressure level in work-performing manner, and an evaporator which is equipped to absorb heat such that the density of the fluid decreases as it passes through the evaporator and the temperature of the mass flow coming from the expander at evaporating pressure and the temperature of the fluid being fed through the evaporator increase. Finally, there is a sub-cooler which is connected downstream of the high-pressure heat exchanger and upstream of the expander, wherein, downstream of the sub-cooler and upstream of the expander, part of the fluid is divertible from the mass flow and expandable by means of a high-pressure regulating valve to an intermediate pressure level so that the fluid which is then at the intermediate pressure level absorbs heat in a counter-flow arrangement in the sub-cooler and thereby additionally sub-cools the mass flow at high pressure level, and also a high-pressure compressor which is mechanically directly connected to the expander and is equipped to compress, to the high-pressure level, only that part of the fluid that is diverted upstream of the expander and is being fed in counter-flow in the sub-cooler, and to mix this fluid, upstream of the high-pressure heat exchanger, with the mass flow coming from the motor-operated main compressor.