EURO-ECO 2009 Hanover 3 - 4 Dezember 2009	Environmental, Engineering - Economic and Legal Aspects for Sustainable Living
	European Academy of Natural Sciences, Hanover European Scientific Society, Hanover University of Bremen, Bremen

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Abstracts EURO-ECO 2009

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The expenditure on ventilation and air conditioning makes up to 60-70 % of the total expendi¬ture for building exploitation, therefore, it is important not only to provide normal hygiene and sanitary conditions of the air, but also to ensure the most rational and efficient engineering solu¬tion in the arrangement of ventilation systems.

Further improvement of ventilation systems is necessary in order to meet requirements on the hygiene and sanitary conditions in the workplace and decrease the metal and energy consumption.

Ventilation of premises is usually provided by an ejection jet in an air funnel and by air removal from premises through the air funnel owing to the kinetic energy of this ejection jet. However, this method does not provide the necessary effi¬ciency due to the insufficient action of the main exhaust ejection jet that does not allow the provi¬sion of comfortable conditions (of concentration and temperature) in the workplace area.

The main purpose of the work was to increase the efficiency of ventilation systems using the ejection properties of a system of exhaust jets.

In the method proposed, the main ejection jet initially forced into the air funnel. Then additional exhaust jets, situated in, are in turn directed into the air funnel according to their location relative to the direction of exhausted air. The stabiliza¬tion of outflow jets and an increase of the effec¬tiveness are reached due to the ejection effect of preceding ejection jets.

The ventilation method is realized as follows. The air funnel is connected with the atmosphere and premises. Ventilators are connected to the premises by exhaust air flues. The ends of force air flues coming from ventilators are located in the funnel in tandem forming ejectors inclined in the direction of exhausted air.

Force stabilization of the drawing out process is achieved by the successive switching on of ven¬tilators in correspondence with the location of ejectors.

Blowing devices greatly influence air mobility in workplaces and attended premises. A mistake in the selection and location of air-distribution units may result in increased air mobility within the premises, that may be injurious to health.

A complex of principally new effective meth¬ods and means of control has been developed. This complex is simple in production, consumes minimal metal and energy and is based on the use of the following gas-dynamic phenomena:

jet closure under the Coand effect on a close limiting surface;
blowing of surrounding air into the jet;
the impact of contradirectional jets;
the formation of a pulsating flow;
the formation of a swirling flow;
jet instability;
transformation of one type of flow into another;
the ejection interaction of out-flowing jets; -jet suppression in circulation zones;
the change of flow ejection before the outflow.

The new ventilation systems developed provide the optimal solution of problems of ecology, power supply and savings of material resources.

 

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