A HEAT EXCHANGER

摘要

A heat exchanger according to the invention comprises a heat exchanging ele- ment (101) comprising heat transferring walls for preventing first fluid and second fluid from mixing with each other and for transferring heat from the first fluid to the second fluid. The heat exchanger comprises one or more rooms containing phase change material capable of storing heat energy by changing from the solid state to the liquid state and releasing the heat energy by changing from the liquid state back to the solid state. The heat exchanger further comprises a cooling channel system (104) for third fluid for cooling the phase change material so as to protect the phase change material against overheating. A heat exchanger of the kind de- scribed above can be used for example as a vaporizer of an energy converter based on for example the Organic Rankine Cycle.