Thermally-Activated Cooling from Low-Temperature Waste Heat

75859 Absorption refrigeration is the only currently available method that utilizes low-temperature waste heat to provide cooling. Unfortunately, absorption cooling systems for commercial and small industrial applications are relatively large and expensive, require costly-to-maintain cooling towers, and are difficult to interface with conventional vapor-compression refrigeration equipment. This project will develop a thermally-activated, Rankine free-piston expander-compressor to supplement the compressor output of conventional mechanically-driven vapor-compression refrigeration, thereby reducing its power consumption. ¿Smart¿ valves and translational counterweights will be used to overcome the limitations of previous designs, thereby providing efficient and vibration-free thermally-activated refrigeration. Phase I will demonstrate feasibility by modeling the dynamics and thermodynamics of the proposed device, projecting its performance over a range of operating conditions, and producing a preliminary design. Commercial Applications and Other Benefits as described by the awardee: The technology should benefit commercial and small industrial energy consumers by providing a practical and cost-effective way to recover useful energy from low-temperature waste heat. Applications include internal combustion engines and microturbine exhaust; boiler, furnace, and oven exhaust; low-pressure steam; solar; and other heat sources with heat output temperatures of 200¿F to 250¿F.