- : # l 6 ooc 4405 Ventilation and Air Quality in Indoor Ice Skating Arenas
There are thousands of indoor ice rink arenas in the United States, Canada, and Europe. The combustion byproducts from the feel-powered ice resurfacing equipment are a potential health risk to both athletes and spectators. A field survey of ten ice rink arenas in Greater Boston and Halifax, Nova Scotia, indicates that the fael type used by the resurfacer as well as the air exchange rate, the air distribution method, and the operation strategy of the ventilation system are significant contributing factors to the indoor air quality (JAQ) . Computational fluid dynamics (CFD) has been used to systematically investigate the impact of the air exchange rate, air distribution method, and ventilation control strategies on the IAQ in an arena. With CFD, it is possible to develop design and operating guidelines for ventilation systems in order to reduce contamination levels in the arenas.
Carbon Monoxide and Nitrogen Dioxide Levels in an Indoor Ice Skating Rink with Mitigation Methods
An indoor ice skating rink is an enclosed space with intermittent air pollutant emissions from fuel-powered ice-resurfacing equipment, such as a resurfacer and an edger. Exhaust gases discharged from the resurfacing equipment actually include significant quantities of carbon monoxide (CO) and nitrogen dioxide (NO[sub 2]) which may induced adverse health effects. Carbon monoxide exposures in ice skating rinks resulting from malfunctioning ice resurfacing equipment were first reported more than twenty years ago. Attempts to reduce emissions of CO and NO[sub 2] form resurfacing equipment, such as the extended exhaust pipe, operation of the air recirculation system or reduced resurfacer operation, appeared not to be effective for maintaining the air pollutant concentrations below guidelines. Even though improved indoor air quality was obtained by the combination of the full operation of the air exhaust system and the reduced number of resurfacer operations in this investigation, these methods may be impractical for most skating rinks. Replacement of the fuel-powered resurfacer with a battery operated resurfacer is recommended. If replacement is not feasible, then increasing the air ventilation rate is recommended as a second choice. 10 refs., 1 fig., 1 tab.
Accurate measurements of output characteristics and detonations of motorbike high-speed racing engine and their optimization at actual atmospheric conditions and combusted mixture composition
Abstract At a motorbike high speed racing engine there is very important an output engine characteristics which depends significantly on a detonation combustion rate, atmospheric conditions and a combusted mixture composition. The combustion process has got a relevant influence on a wear degree of main engine parts or on their damage eventually. The detonation combustion rate is very important because this kind of burning can be not only destructive but a useful phenomenon, as well. If the process of detonation burning is kept on a certain level, it can help significantly to the next increasing of an engine power output. In this article there is described the measurements of output characteristics of a high-speed racing engine which were performed by means of a data-recording system and the detonation combustion was evaluated using a quantitative method. The actual values of atmospheric conditions and the mixture composition were added to the measured values. Then the obtained values are compared visually with a damage degree of an engine piston caused by the detonation burning. The result is a limit value expressed in a number of detonation units related to a run distance interval of the vehicle driven by the high-speed racing engine. In framework of this run distance interval there is the process of detonation burning profitable. As well as it increases an engine power output and together it is not destructive with regard to engine design parts.