Microturbine with new design of nozzles

The article presents a new technical solution for designingmicroturbine nozzles. The nozzles have a rectangular cross section, the longitudinal axis of the accelerating section is straight, and its projection onto the plane of the nozzle is placed at a tangent to thecircle formed by the middle diameter of the turbine. This makes it possible to increase the efficiency of the microturbines, which have nozzles with outlet angles from 5° to 9°.Microturbine efficiency research was carried on an experimental turbine. The studied turbine power reached 80 kW. The authors submit an empirical model makes it possible to predict the efficiency of a microturbine and determine the values of the factors corresponding to the maximum efficiency mode. Through optimization, the efficiency of the investigated microturbine stages reached 0.62 with tapered nozzles. The other parameters were: the nozzle outlet angle - 5°; the rotor blade input angle - 8.1°; the dimensionless peripheral speed - 0.44; the degree of pressure reduction per stage - 19.7.