Research on the dynamic heat transfer of stratified air conditioning zone building surfaces in large space scale rig based on low supply-middle return.

Abstract

Radiation heat and convection heat exist on stratified air conditioning zone building surfaces in large space, and they have significant impact on cooling load calculation and thermal comfort analysis. Actually, heat transfer in large space is usually under non-steady condition. Based on an actual large space, a 1:4 scale model experiment rig is built as research object, which has: typical sloping ceiling structure, columnar low supply air, middle return air, inner surfaces periodic heat flow simulation system, heat measurement, and control system. For stratified air conditioning zone building surfaces in large space, radiation heat transfer calculation model is presented based on Gebhart radiation model and radiation heat is calculated by matrix calculation. Convection heat transfer calculation formula is presented based on inner surfaces temperatures and indoor air temperatures. Taking two periodic heat flow experiment conditions, building surfaces temperatures and indoor air temperatures of stratified air conditioning zone in large space were collected, taking model calculation program to compute dynamic radiation heat and convection heat. The result indicated the dynamic characteristics of radiation heat and convection heat of stratified air conditioning zone building surfaces in large space. It provided some important information for dynamic heat transfer research in stratified air conditioning zone building surfaces in large space.