상변화물질을 이용한 이동식 개인 공조시스템 해석

Abstract

This study aimed to estimate the performance of a storage cooling system for roving personal air conditioning where a phase change material (PCM) was used as a condenser. The modeling on direct expansion air conditioning requires two-phase analysis. We applied 1-D two phase flow method for refrigerant inside tubes and effective thermal conductivity model outside tubes for PCM. Results were compared with those of a previous experience model which assumed a fixed ratio of super-heating region (10%), two-phase region (80%), and sub-cooling region (10%). The desired system discharge power was 600 Wh. Results showed that the previous experience method had an over-estimated performance due to the assumption of constant temperature applied over whole tube length while the current model coupled with 1-D two phase model and effective thermal conductivity model could cover the detailed heat transfer involved in the roving personal air-conditioning including developing a two-phase region.