Heat transfer system employing supercooled fluids

In a system for converting heat energy to mechanical energy, a working fluid is vaporized and then permitted to expand in an expander. The vaporized working fluid is introduced to a condenser including a container and a conduit for guiding the working fluid through the container. A condensing medium in a generally solid state is disposed in the container in contact with the conduit to absorb heat from and thereby condense the working fluid. In response to the absorbed heat, the condensing medium liquifies, in which state it can be supercooled at ambient temperatures and stored for an extended period of time. The supercooled condensing medium can be triggered at a predetermined time to release the absorbed heat to the system. The provision of a super-coolable condensing medium in the condenser minimizes the heat loss thus providing a significant increase in the overall efficiency of the system.