Influence of the degree of off-design of the traction nozzle of a jet reaction turbine on its efficiency

Abstract

Abstract At the present stage of social development, the need for rational use of energy resources of the planet is particularly acute. Most countries have already faced the problem of the energy crisis. An appropriate way to solve this problem is the utilization of secondary energy resources. With the help of turbine generators, it is possible to reduce the pressure and utilize the potential energy of excess pressure of gas or vapours to produce electricity. Such units can be created based on a jet reaction turbine. The study aims to assess the impact of the degree of off-design of the traction nozzle on the efficiency of the jet reactive turbine. The analysis of the factors influencing the efficiency of the jet reaction turbine is carried out in the work. The obtained efficiency rate for the jet reactive turbine depending on the given dimensionless velocity of λout t at the inlet pressure of the inlet nozzle of 2, 4, 6 and 10 MPa in the design mode (at the degree of off-design of S = 1) and in the off-design modes of operation ( S> 1). Graphical dependencies of the jet reaction turbine efficiency rate on the given circular velocity of the impeller are constructed (U− = 0… 0.7). The research shows that with increasing pressure at the inlet to the inlet nozzle, the efficiency rate of the turbine increases, and the optimum of the efficiency rate is shifted towards the increase of the given circular velocity of the impeller, both in the design and off-design operating modes. It is found that the greatest value of the efficiency rate is acquired at the design mode of operation of the traction nozzle, i.e. at S = 1.