TIAX LLC — Department of Defense SBIR Phase II: The purpose of this topic is to develop a pump that can pump two-phase, liquid and vapor m

Description

The purpose of this topic is to develop a pump that can pump two-phase, liquid and vapor mixtures of common refrigerants and heat transfer fluids, without oil lubrication. The challenges of pumping in this regime are well known: Two-phase, liquid-vapor refrigerant mixtures are a mixture of saturated liquid and saturated vapor, by definition meaning that there is zero net positive suction head. Many pump types are highly susceptible to cavitation under these conditions, leading to rough operation, poor performance, and erosion and ultimate destruction of pump elements, especially centrifugal pump impellers. The common fluorocarbon refrigerants and heat transfer fluids are generally low in liquid viscosity and offer no boundary lubrication type lubricity, making mechanical design of a pump to handle these fluids challenging with respect to both mechanical friction losses and the wear life of rotating shafts, bearings, and pump elements. To meet the need for a pump that can handle two-phase, saturated liquid-vapor mixtures of refrigerants and similar heat transfer fluids, TIAX proposes to continue the development of a scroll type pump that is tailored specifically for this purpose.