Flat plate heat pipe collectors made by roll bonding

Roll bonded heat pipes for solar collector applications are discussed. Thermodynamics of roll bonded plates with integrated heat exchanger were examined for different geometrical configurations. Prototypes were laboratory checked and modified. A strength problem occurred with increasing heat pipe pressure in the temperature range 130 to 200 C. Deformation of plates can be avoided by a pressure relief system. A version with three interrelated rolled sheets and an auxiliary stiffening channel structure at the rear side improves results without a pressure relief system. It is concluded that application of roll bonded heat pipes for solar collectors is not economical.