Heaters for thermal energy transformation installations

In an installation for the transformation of thermal energy into mechanical energy by causing a condensable fluid to effect a thermodynamic cycle through vapor generating means, vapor heating means, vapor condensing means, and vapor using means, said vapor heating means comprising a first heat exchanger within which are incorporated separate desuperheating, condensation and supercooling zones, each of said zones comprising at least one tube having a wall through which heat is exchanged between a condensable fluid flowing within said tube and a second condensable fluid flowing outside said tube, the improvement which comprises a separate first nest of heat exchange tubes formed in the shape of a triple U in said condensation and supercooling zones within said first heat exchanger and a separate second nest of spirally wound heat exchange tubes in said desuperheating zone within said first heat exchanger, each nest of heat exchange tubes having inlet and outlet ends.