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Heat-Pipe reflux receivers have been identified as a desirable interface to couple a Stirling engine with a parabolic dish solar concentrator. The reflux receiver provides power uniformly and nearly isothermally to the engine heater heads while de-coupling the heater head design from the solar absorber surface design. Therefore, the heat pipe reflux receiver allows the receiver and heater head to be independently thermally optimized, leading to high receiver thermal transport efficiency. Dynatherm Corporation designed and fabricated a screen-wick heat-pipe receiver for possible application to the Cummins Power Generation, Inc. first-generation 4kWe free-piston dish-Stirling system, which required up to 30 kWt. The receiver features a composite absorber wick and a homogeneous sponge-wick on the aft dome to provide sodium to the absorber during hot restarts. The screen wick is attached to the absorber dome by spot welds.

Particle mass and size distribution measurements have been made on the exhaust of an Onan prechamber diesel engine. Seven fuels were examined: no. 1 and no. 2 diesel fuel, 40 and 50 cetane number secondary reference fuels, and no. 2 diesel fuel doped with three different concentrations of Lubrizol 565, a barium-based smoke suppressant. The no. 1 and no. 2 diesel fuels and the 50 cetane number reference fuels produced very similar emissions with emission indices in the range 0.3-1.3 mg (gm-fuel)-1 and volume mean diameters between .09 and 0.15 μm. The 40 cetane number reference fuel produced both smaller emission indices, 0.2 to 0.8 mg (gm-fuel)-1, and particle diameters, 0.03 to 0.09 μm. These reductions were apparently related to the longer ignition delay period of the 40 cetane number fuel, which allowed better mixing of the fuel and air prior to combustion.