Paper 6
The Use of Impulse
Ventilation to Control Pollution in
Underground Car Parks
João
Carlos Viegas
National
Laboratory of Civil Engineering, Buildings Dept., Av. Brasil, 101,
1700-066 Lisboa, Portugal
Abstract
The ventilation of underground car parks is
important to avoid health problems associated with the inhalation of
combustion products released by car engines, in particular carbon monoxide
CO (which is commonly used as the indicator of car park indoor air
quality). In recent years, a new mechanical ventilation system has
appeared, based on the use of axial ventilators (jet fans) suspended under
the car park ceiling. In this paper the flow generated by jet fans and
their effects on pollutants are studied. It is concluded that jet fans may have a pumping effect, entraining the surrounding
contaminated air into the jet. In this way jet fans are able to restrict
the dispersion of contaminants, provided that the exhaust flow rate from
the car park is not lower than the jet flow rate. Impulse ventilation may
also provide fast dilution of the local pollution peaks, but in this case
the removal efficiency will be low. This paper also suggests criteria to
define the distance between jet fans.
Key words: impulse ventilation, axial ventilators, carbon monoxide, underground car
park, jet fan, CFD.
References
Blevins RD: (1984)
“Applied fluid dynamics handbook”. Van Nostrand Reinhold Company.
BS 7346-7:2006:
(2006) “Components for smoke
and heat control systems – Part 7: Code of practice on functional
recommendations and calculation methods for smoke and heat control systems
for covered car parks”. London: British Standards Institute.
Chan
MY and Chow WK: (2004) “Car
park ventilation system: performance evaluation”. Building and
Environment, 39, pp635-643.
Chow
WK: (1995) “On the ventilation
design in underground car parks”. Tunnelling and Underground
Space Technology, 10, (2), pp225-246.
Chow
WK: (1996) “Simulation of
carbon monoxide level in enclosed car parks using an air flow network
program”. Tunnelling and Underground Space Technology, 11,
(2), pp237-240.
Chow
WK: (1998) “On Safety Systems
for Underground Car Parks”. Tunnelling and Underground Space
Technology, 13, (3), pp281-287.
Chow
WK: (2001) “Numerical studies
of airflows induced by mechanical ventilation and air-conditioning (MVAC)
systems”. Applied Energy; 68, pp135-159.
Duci
A et al: (2004) “Numerical
approach of carbon monoxide concentration dispersion in an enclosed
garage”. Building and Environment, 39,
pp1043–1048.
Hinze JO and Zijnen BG: (1949) “Transfer of heat and
matter in the turbulent mixing zone of an axially symmetrical jet”.
Journal
Appl. Sci. Res. A1.
Lin,
Zhang et al: (2006) “CFD
analysis of ventilation effectiveness in a public transport interchange”.
Building and Environment, 41, pp254–261.
Likar
J and Čadež J: (2000) “Ventilation
Design of Enclosed Underground Structures”. Tunnelling and
Underground Space Technology, 15, (4) pp477-480.
McGrattan K: (2005)
“Fire Dynamics Simulator (Version 4). Technical Reference Guide”. NIST,
NISTSP 1018.
Papakonstantinou
K et al: (2003) “Air quality in an underground garage: computational and experimental
investigation of ventilation effectiveness”. Energy and
Buildings, 35, pp933–940.
Viegas DX: (1981)
“Uma técnica de erosão aplicada ao estudo da interacção de jactos
turbulentos com uma superfície plana”. Coimbra.
Viegas
JC and Saraiva JG: (2001) “CFD Study of smoke control inside enclosed
car parking”. Proceedings
of Interflam
2001, 9th International Fire Science & Engineering Conference.
Edinburgh: Interscience communications.
Viegas JC and Saraiva JG (2002) “Avaliação com recurso a
CFD da aplicação de ventiladores de impulso a parques de estacionamento
cobertos”. Proceedings of Métodos Numéricos en Ingenieria V. Madrid: SEMNI.
Viegas
JC: (2006) “The
Use of Jet Fans to Improve the Air Quality in Underground Car Parks”. Proceedings
of Healthy Buildings 2006 Conference. Lisbon.
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