Model Turbine Design for Small-Scale Waste Heat Recovery

Waste heat recovery operations typically require at least 500 kW of waste heat. However, there is an large untapped potential for waist heat recovery at lower power levels. This study explored the design of a small gas/vapor turbine for waste heat recovery operation on the order of 5 kW. Steam and gas turbines are typically not designed for such low power applications. The volumetric flow rate, temperature, and pressure of an air compressor were measured to characterize a fluid flow, finding that air at 22 °C and 86 psi was available at a flow rate of 0.067 Lps. Similarity was implemented to determine a power output of a small model turbine that would produce 5 kW for a full prototype turbine. The model turbine was designed in SolidWorks and 3D printed. The inlet diameter used was 20 mm for the rotor casing and 10 mm for the rotor hub. An ideal Rankine cycle was used to determine the potential heat input needed for a 5 kW turbine to function properly. The costs and benefits were roughly estimated to determine if this small-scale heat loss recovery is viable and profitable.