Sizing and Optimization of a Vortex Tube for Electric Vehicle HVAC Purposes 2021-24-0099

In the recent past, an always increasing attention have been addressed to the definition and optimization of the HVAC system for fully electric vehicles. The new vehicle layouts and the different operating temperatures of the whole powertrain ask for a re-thinking of the HVAC concept for the modern architectures. In this ballpark, the possibility to deal with a compact and efficient apparatus without moving parts and capable to provide both cold and hot fluxes is really attractive. This is the reason why this work deals with the design and optimization of a vortex tube for automotive applications. Such a component, in fact, is capable to separate a highly swirled flow in two different branches, a cold one and a hot one (one inlet - two outlets). The balance in between the two obtained mass flows can be simply realized via ruling the backpressure at the hot side, with keeping constant the cold one. After a preliminary sizing activity, where the best compromise in between vortex tube dimensions and achievable mass flow rate has been evaluated, a detailed optimization procedure has been carried out in order to find the optimal operating points so to answer to cooling demand. More specifically, starting from the mass flow and temperature requirements for a critical steady state point referred to a commercial M-class vehicle, the whole sizing/optimization procedure has been developed. Obtained results are pretty encouraging, with appreciable results in terms of cold mass flow rate and realizable cold temperatures. Nevertheless, some additional reasoning should be addressed to the integration of such a component in a working layout, especially in terms of integration with compressors and diffusers to be placed at vortex tube inlet and cold outlet respectively.