Heat exchanger applicable more particularly to compressor heat pumps

A heat exchanger system operating with a fluid having both a liquid and gaseous phase, including:

• a fluid circuit for a fluid having a liquid phase when compressed and cooled and a gaseous phase when heated and at a reduced pressure,
• a pair of heat exchangers in said fluid circuit, both of which can operate alternatively as a condenser and an evaporator,
• compressor means connected in said fluid circuit to said heat exchangers for compressing said fluid when in a gaseous phase,
• an accumulator-exchanger connected in said fluid circuit to said compressor means and a pressure reducer connected with the accumulator exchanger,
• for each heat exchanger four non-return valve means in said fluid circuit connected for maintaining inside each said exchanger the flow direction of the fluid during condensing and evaporating operation thereof,
• a changeover valve in said fluid circuit associated with the compressor means, the accumulator exchanger and the pressure reducer, to maintain inside these three components the same direction of fluid flow, said changeover valve having means operable to a first position controlling the fluid under pressure for setting the non-return valves so that the fluid flow causes a first heat exchanger to operate as an evaporator, and a second heat exchanger to operate as a condenser, thereby heating incoming air to the system, the last-mentioned means being operable to a second position controlling the fluid under pressure for setting the non-return valves so that the first heat exchanger operates as a condenser, and the second heat exchanger operates as an evaporator, thereby cooling incoming air to the system.