Abstract: A rod seal system having a pair of rod seals that form a buffer area between a high pressure area containing working gas and a low pressure area of a heat engine, such as a Stirling cycle engine. A pump that becomes passively charged with working gas at relatively low pressure and which releases working gas at relatively high pressure when actuated is used to force working gas from the buffer area to the high pressure area through a conduit. The working gas may be hydrogen gas and the pump may be a metal hydride pump that is thermally actuated. The low pressure area may contain air and lubricant at atmospheric pressure. A system for separating the lubricant collecting within the buffer area and reintroducing the lubricant into the low pressure area can also be incorporated into the rod seal system.

Abstract: A combustor for a heat engine, such as a Stirling cycle heat engine, incorporating a number of nozzles mounted between a pair of plates. Fuel is introduced from above the plates into mixing chambers within the nozzles. Combustion inlet air passing between the plates is introduced into the mixing chambers and create a swirling motion in the fuel/air mixture. The fuel/air mixture passes through an expansion chamber before being discharged to a common combustion chamber. The combustor has been designed to allow the use of high temperature combustion inlet air and to have low NOx emission characteristics.

Abstract: A heater assembly for a heat engine designed to utilize solar energy and heat produced by combustion of a fuel such as natural gas. A receiver housing allows concentrated solar energy to be directed through a receiver aperture into a receiver chamber. Inner and outer arrays of heater tubes within the receiver chamber absorb the solar energy and transfer heat to working fluid in the heater tubes. A burner within the housing produces combustion gases which circulate past the heater tubes and transfer heat to the working fluid. The heater tubes form an opaque surface to solar energy and have uniform gaps which allow heated fluid to be passed between adjacent heater tubes. A precise three-dimensional mathematical description for the centerlines of the heater tubes which maintains uniform gaps between adjacent heater tubes is disclosed.