Numerical analysis of an air-conditioning energy-saving mechanism

Abstract

This paper presents a new concept in energy-saving equipment, namely, a regional air-conditioning mechanism (RACM). The RACM system is constructed with an inlet and an outlet in a main duct centered in a cylindrical housing. The RACM produces an airflow circulation cell for satisfying the thermal comfort demands of users, and can potentially be energy-saving. This study targets two areas: (1) study the effect of cool air inlet velocity (V _inlet), negative outlet pressure (P _out), and distance between floor surface and outlet port (L ₂) of an airflow circulation cell, and (2) determine their suitable adjustments for creating a better method for using computational fluid dynamics (CFD). Experimental platforms were set up to test the validity of a simulation model, and the tested results showed good agreement with simulation. In the study, nine simulated case studies divided into three groups with various values of V _inlet, P _out, and L ₂ were analyzed. Case four of group two, V _inlet = 0.3 m/s, P _out = −2 Pa, and L ₂ = 0.5 m, yielded the lowest energy consumption and the highest level of thermal comfort demands. Group one, in which P _out, and L ₂ were fixed for all case studies, except values of V _inlet, resulted in the most sensitive in terms of vertical temperature distribution along the body of a sedentary occupant in the room. The two thermal regions of the tested environment, i.e., occupied zone and the rest of the room, evidently experienced different temperatures in the simulated room. It was concluded that the RACM is a potential candidate for portable air-conditioning in enclosed spaces.