ТЕХНІЧНЕ Й ЕКОЛОГІЧНЕ ОБҐРУНТУВАННЯ ВИБОРУ ТИПОРОЗМІРІВ ГІДРОТУРБІН ДЛЯ НИЗЬКОНАПІРНИХ МАЛИХ ГЕС

Abstract

The purpose of the work is to minimize the harmful impact on the environment of low-pressure micro-hydropower plants, which are equipped with axial propeller hydro turbines and give all generated electricity to the grid at a preferential "green" tariff. Methodology. Analytical methods have been used in the theoretical studies described in this article. Findings. At small low-pressure hydropower plants up to 100 kW, 2 or 3 hydraulic units with different geometrically similar propeller turbines should be installed. We have proven this from economic, technical and environmental points of view. The proportionality factor of the impeller diameters of these turbines shall be √2. Originality. We have analytically determined a denominator of geometric progression equal to √2 to create a model row of propeller geometrically similar hydro turbines for small hydroelectric power plants (i.e., the proportionality factor of the impeller diameters of any two adjacent turbine sizes must be equal to √2). Practical value. The results of the studies can be used in practice when designing propeller hydro turbines for small hydroelectric power plants up to 100 kW, which operate at pressures up to 5 meters of water column. Conclusions. It is established that the best option for ecological and economic reasons is the equipping a small hydroelectric power plant up to 100 kW and a head of up to 5 m with three different propeller turbines – large, medium and small – with a 4:2:1 ratio of water consumption. This option allows for uniform discrete seven-stage regulation of water flow by the station with the following characteristics: depth of control – 86%, discretion of regulation – 14%. In this case, the relative water consumptions by the station may take the following values: 100%, 86%, 71%, 57%, 43%, 29%, 14%. Slightly worse in terms of ecology, but economically preferable option with two different propeller turbines – large and small – with a 2:1 ratio of water consumption. It allows providing a uniform discrete three-stage regulation of water flow by the station with the following characteristics: depth of regulation – 67%, discretion of regulation – 33%. In this case, the relative water consumptions by the station can take the following values: 100%, 67%, 33%.