INCREASE OF ENERGY EFFICIENCY OF VENTILATION SYSTEMS BY MEANS OF PROFILING PHASON ELEMENTS
The article discusses the issues of reducing the energy consumption of ventilation systems. A detailed analysis is given and the results of the studies of the flows carried out by the authors in the shaped elements of the air duct networks, in particular, in exhaust hoods, asymmetric exhaust tees, are summarized; also presents the results of numerical and experimental studies of the outlines of the vortex zones formed when the flow is disrupted from the inlet edge of the middle and last side exhaust openings of the air ducts. Numerical studies were performed using the Ansys Fluent software package. Based on the data obtained, numerical modeling was carried out and improved designs of fitting elements profiled according to the outlines of the vortex zones were implemented. The results of numerical studies are verified experimentally. It is shown that for all investigated fittings, the use of profiling leads to a significant decrease in their resistance. A decrease of local drag coefficient by a value of 30% to 60% was obtained depending on the design and operating parameters of the fitting elements. For the sizes of a number of fittings, in particular, the inlet sections of the exhaust side and end openings, a geometric similarity was found to the outlines of the vortex zones of the flows. Graphic and analytical dependencies are obtained for determining the local drag coefficients of energy-efficient fittings and its outlines of the vortex zones. This will allow us to design improved fittings in the design, construction of new and reconstruction of existing duct networks of ventilation and air conditioning systems. The use of profiled fittings will lead to reduction in operating costs due to the saving of electric energy on the fan drive and the reduction of capital investments in the facility due to the possibility of using a ventilation unit of lower power and size.