FIELD: heating.
SUBSTANCE: cooling circuit for circulation of carbon dioxide as cooling agent in it has the first expansion device for expansion of cooling agent from high pressure to intermediate pressure and the second expansion device for expansion of cooling agent from intermediate pressure to evaporation pressure. The first expansion device is made in the form at least of two in-parallel connected valves (a, b, c, d) so that in case of failure in the valve (a) or at the valve (a) the latter is switched off, and at least one of the remaining operating valves (b, c, d) continues providing the controlled operation of cooling circuit.
EFFECT: use of invention excludes the need for switching off the whole cooling circuit in case of failed valve.
13 cl, 1 dwg
