Design of Air Diffusion Terminal Devices in Passenger Train Vehicle
Publication: Journal of Environmental Engineering
Volume 123, Issue 12
Abstract
The ventilation system design for better environment in the passenger train vehicles in Hong Kong is discussed. Mean air speed is an important factor on thermal comfort. Macroscopic flow numbers including the Archimedes number, the Reynolds number, and the throw of diffusers are recommended to be design parameters, for determining the mean air speed in the occupied zone of the train compartment. Empirical equations derived earlier are recommended to be used in the design of air diffusion terminal devices for providing a better environment in the passenger train vehicles. It is found that the supply inlet air jet would not sufficiently penetrate into the occupied zone when passengers are closely packed together in a train vehicle. For maintaining an acceptable mean air speed of 0.15 m s−1 at the occupied zone in this example, supply air inlet jet of high inlet velocity (15.2 m s−1) and low temperature (6°C) should be provided. Air diffusion terminal devices have to be selected carefully in order to improve the indoor air quality inside train vehicles. Diffusers of thinner width are recommended, and they should be placed closely together (0.406 m).
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
ASHRAE. (1989). ASHRAE Standard 62-1989. “Ventilation for acceptable indoor air quality.” American Soc. of Heating, Refrigerating, and Air-Conditioning Engrs., Atlanta, Ga.
2.
ASHRAE. (1992). ASHRAE Standard 55-1992. “Thermal environmental conditions for human occupancy.” American Soc. of Heating, Refrigerating, and Air-Conditioning Engrs., Atlanta, Ga.
3.
ASHRAE. (1993). ASHRAE Handbook—Fundamentals 1993. American Soc. of Heating, Refrigerating, and Air-Conditioning Engrs., Inc., Atlanta, Ga.
4.
Chow, W. K. (1996). “Ventilation design for train compartments.”Res. Rep., The Hong Kong Polytechnic University, Hong Kong.
5.
Chow, W. K., and Fung, W. Y.(1994). “Investigations of the subjective response to elevated air velocities: Climate chamber studies.”Energy and Buildings, 20(3), 187–192.
6.
Chow, W. K., and Wong, L. T.(1994). “Experimental studies on air diffusion of a linear diffuser and associated thermal comfort indicies in an air-conditioned space.”Building and Environment, 20(4), 523–530.
7.
Chow, W. K., and Wong, L. T.(1996). “Experimental studies on the air flow characteristics induced by a high-sidewall grill in a climate chamber.”Indoor and Built Environment, 5(2), 82–98.
8.
CIBSE. (1986). Guide A1. Environmental criteria for design. Chartered Inst. of Build. Services Engrs., United Kingdom.
9.
Funakoshi, S., and Matsuo, K. (1993). “PMV-based train air-conditioning control system.”ASHRAE Transactions, Research, Vol. 99, Pt. 2, 423–430.
10.
Hong Kong Standards. (1996a). MTRC accepts blame for chaos. May 8, 1, Hong Kong.
11.
Hong Kong Standards. (1996b). MTRC must make its import public. May 8, 12, Hong Kong.
12.
ISO. (1994). ISO Standard 7730. “Moderate thermal environments—determination of the PMV and PPD indices and specification of the conditions for thermal comfort.” Int. Standards Organization, Geneva, Switzerland.
13.
Li, Z. H., Zhivov, A. M., Zhang, J. S., and Christiansen, L. L. (1993). “Characteristics of diffuser air jets and airflow in the occupied regions of mechanically ventilated rooms—a literature review.”ASHRAE Transaction, Vol. 99, Pt. 1, 1119–1127.
14.
Ming Poa. (1996). MTRC ventilation system. May 8, Hong Kong (in Chinese).
15.
Mullejans, H. (1996). “The similarity between non-isothermal flow and heat transfer on mechanically ventilated rooms.” Trans. 202, Heating and Res. Assoc., Brackwell.
16.
Randall, J. M., and Battams, V. A.(1979). “Stability criterion for airflow patterns in livestock buildings.”J. of Agric. Engrg. Res., 24, 361–374.
17.
Skistad, H. (1994). Displacement ventilation. Research Studies Press Ltd., London, United Kingdom.
18.
Spitler, J. D. (1990). “An experimental investigation of air flow and convective heat transfer on enclosures having large ventilative flow rates,” PhD thesis, Univ. of Illinois at Urbana, Champaign, Ill.
19.
Sun Poa. (1996). July 7, Hong Kong (in Chinese).
20.
Whittle, G. E. (1986). “Room air draught: design and evaluation.” Tech. note 4/86, Build. Services Res. and Information Assoc., London, United Kingdom.
21.
Wong, L. T. (1997). “A study on the building air flow induced by environmental control systems and characteristics of air diffusion devices,” PhD thesis, The Hong Kong Polytechnic University, Hong Kong.
22.
Zhivov, A. M. (1993). “Theory and practice of air distribution with included jets.”ASHRAE Transactions, Vol. 99, Pt. 1, 1152–1159.
Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 123 • Issue 12 • December 1997
Pages: 1203 - 1207
Copyright
Copyright © 1997 American Society of Civil Engineers.
History
Published online: Dec 1, 1997
Published in print: Dec 1997
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.