Abstract: A heat exchanger comprises a matrix made up of alternate layers of generally planar sheets and generally corrugated sheets which cooperate to define a plurality of parallel passages for first and second heat exchange fluids. Alternate of the passages defined by each of the corrugated sheets and its adjacent planar sheets are adapted for the passage of a first heat exchange fluid and the remainder adapted for the passage of a second heat exchange fluid. The ony bonding together of the planar sheets and corrugated sheets is along those portions of their peripheries which are parallel with the defined passages.

Abstract: The working medium of a gas turbine engine power plant is heated indirectly by energy derived by solar radiation, the power plant comprising radiant energy collecting means, radiant energy receiving means, radiant energy heat transfer means, a relatively large capacity pressurized heat store and a gas turbine engine in which the compressed air is heated by heat energy in the heat store.

Abstract: A radiant energy heat exchanger for use in a solar energy power plant comprises one or more banks of heat exchange ducts, the or each bank of ducts having an inlet and an outlet manifold to receive and discharge respectively the medium to be heated, the ducts all being curved along their length between the inlet and outlet manifolds so that the amount of radiant energy falling on the ducts per unit area of duct decreases between the inlet and outlet manifolds at such a rate that the duct temperature is substantially constant between the manifolds while the temperature of the medium being heated increases, the radiant energy falling on the ducts being substantially unidirectional.