Knowledge of air flow patterns and thermal parameters are essential in the design of a ventilation system for large enclosures. The objective of this paper is to evaluate the possibility of using computer simulation to predict the airflow pattern and removal effectiveness of ventilation systems in large enclosures. The quality of air and thermal comfort in a three-floor shopping center are studied by the computational fluid dynamics (CFD) method. Two ventilation systems are selected. In System 1, rooms are ventilated by two ceiling slot diffusers, supplying air downward into the rooms. The halls are equipped with wall jet diffusers delivering air in a horizontal direction. Airflow and air quality, under both summer and winter conditions, are investigated. In System 2, the air in each room is supplied in a radial manner by four ceiling rectangular diffusers. The hall and balconies have jet diffusers which supply air vertically downward. Different ventilation rates, outdoor air ratios and supply air temperatures are studied. Occupants are simulated by heat and CO2 sources without aerodynamic blockages. It was found that the summer and winter air temperature differences in the shopping center differ by approximately 2°C. The rectangular air diffusers should he used in the rooms and the jet diffusers in the halls and balconies. Both the variable air volume and the constant air volume methods, with an adjusted supply air temperature, can be used for air conditioning control in a large enclosure.

Issue Section:
Research Papers
Topics:
Air flow, Air pollution, Diffusers, Temperature, Ceilings, Computational fluid dynamics, Ventilation, Ventilation equipment, Air conditioning, Carbon dioxide, Computer simulation, Design, Heat
1.
“ASHRAE 62-1989,” 1989, ASHRAE Standard: Ventilation for Acceptable Indoor Air Quality, American Society of Heating, Refrigeration and Air Conditioning Engineers, Atlanta, GA.
2.
Chen, Q., and Jiang, Z., 1992, “Significant Questions in Predicting Room Air Motion,” ASHRAE Transactions, Vol. 98, Part 1.
3.
Chen
 
Q.
,
Moser
 
A.
, and
Huber
 
A.
,
1990
, “
Prediction of Buoyant, Turbulent Flow by a Low-Reynolds-number k – ε Model
,”
ASHRAE Trans.
Vol.
96
, No.
1
, pp.
564
–
573
.
4.
Chien
 
K. Y.
,
1982
, “
Prediction of Channel and Boundary-Layer Flows with a Low-Reynolds-number Turbulence Model
,”
AIAA Journal
, Vol.
20
, No.
1
, pp.
33
–
38
.
5.
Fanger
 
P. O.
,
Melikov
 
A. K.
,
Hanzawa
 
H.
, and
Ring
 
J.
,
1989
, “
Turbulence and Draft: The Turbulence of Airflow has a Significant Impact on the Sensation of Draft
,”
ASHRAE J.
, Vol.
31
, No.
7
, pp.
18
–
23
.
6.
Haghighat
 
F.
,
Jiang
 
Z.
,
Wang
 
J. C. Y.
, and
Allard
 
F.
,
1992
, “
Air Movement in Buildings Using Computational Fluid Dynamics
,”
ASME JOURNAL OF SOLAR ENERGY ENGINEERING
, Vol.
114
, pp.
84
–
92
.
7.
Jones
 
W. P.
, and
Launder
 
B. E.
,
1972
, “
The Prediction of Laminarization with a Two-Equation Model of Turbulence
,”
Int. Journal of Heat and Mass Transfer
, Vol.
15
, pp.
301
–
314
.
8.
Lam
 
C. K. G.
, and
Bremhorst
 
K.
,
1981
, “
A Modified Form of the k – ε Model for Predicting Wall Turbulence
,”
ASME Journal of Fluids Engineering
, Vol.
103
, pp.
456
–
460
.
9.
Launder
 
B. E.
, and
Sharma
 
B. I.
,
1974
, “
Application of the Energy Dissipation Model of Turbulence to the Calculation of Flow Near a Spinning Disc
,”
Letters in Heat and Mass Transfer
, Vol.
1
, No.
2
, pp.
131
–
138
.
10.
Rosten, H. I., and Spalding, D. B., 1987, “The PHOENICS Reference Manual: Version 1.4,” Report TR200, London, CHAM Ltd.
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