New solar Stirling engine TNT-1 with direct internal radiation heating

A unique 1 kW solar Stirling engine called TNT-1 (for Tohoku Gakuin Univ., Nihon Univ., and Tohoku Electric Power), utilizing N. Isshiki´s (1984) internal solar heating method and two solar concentrator dishes, is under test as a prototype for future large-scale solar engine systems. The Stirling engine has a transparent cylinder head made of quartz glass, and the solar beam concentrated by the solar dish heats up internal meshes installed on the displacer directly from the outside through the glass. As a result the engine can have a very simple heater with small dead volume and with enough heating surface, using wire mesh only, to provide high efficiency and low cost. One solar dish is a very accurate parabolic concentrator consisting of 180 small, accurate glass mirrors; the other consists of 40 simple spherical mirrors composed of plastic plates