Numerical Study on Coupled Operation of Stratified Air Distribution System and Natural Ventilation under Multi-Variable Factors in Large Space Buildings

Ziwen Dong,Liting Zhang,Hao Huang,Qifen Li,Yongwen Yang

doi:10.3390/en14238130

Abstract

Stratified air distribution systems are commonly used in large space buildings. The research on the airflow organization of stratified air conditioners is deficient in terms of the analysis of multivariable factors. Moreover, studies on the coupled operation of stratified air conditioners and natural ventilation are few. In this paper, taking a Shanghai Airport Terminal departure hall for the study, air distribution and thermal comfort of the cross-section at a height of 1.6 m are simulated and compared under different working conditions, and the effect of natural ventilation coupling operation is studied. The results show that the air distribution is the most uniform and the thermal comfort is the best (predicted mean vote is 0.428, predicted percentage of dissatisfaction is 15.2%) when the working conditions are 5.9% air supply speed, 11 °C cooling temperature difference and 0° air supply angle. With the coupled operation of natural ventilation, the thermal comfort can be improved from Grade II to Grade I.

Highlights

The large-space buildings of the airport operate non-stop throughout the year and have a long daily use time
The main influencing factor of indoor airflow organization is the ratio of heat gain in air-conditioned areas and non-air-conditioned areas
Reasonable layout of natural ventilation is conducive to indoor air distribution to achieve thermal comfort indicators

Summary

Introduction

The large-space buildings of the airport operate non-stop throughout the year and have a long daily use time. In terms of HVAC systems, stratified air-conditioning systems [9,10], the use of natural ventilation [11], and the simulation of airflow organization in the terminal [12] are all effective measures to reduce energy consumption. Most scholars concentrated on studying the airflow organization under the influence of different single factors of stratified air conditioning, ignoring the result of multiple factors and lack of specific analysis of the coupled operation of stratified air conditioning and natural ventilation. These overlooked issues will have an impact on the airflow organization and thermal comfort of the stratified air conditioner.

Physical Model

Numerical Calculation

Boundary Conditions

Results and Discussion

Coupling of Stratified Air Conditioning and Natural Ventilation

Conclusions