Experimental analysis of organic Rankine cycle power generation system with radial inflow turbine and R245fa

Lei Li,Qing-Qing Liu,Le-Ren Tao

doi:10.1177/1687814020921663

Abstract

Small turbines must operate at high rotational speeds to generate adequate output power. In this study, a radial inflow turbine using R245fa as the working fluid is miniaturised and is designed to have a rotational speed of 30,000 r/min. The organic Rankine cycle system is not simplified, and a preheater and a superheater are installed. The turbine is experimentally analysed in the organic Rankine cycle system. The experimental results show that with an increase in the inlet pressure, the turbine output power and system efficiency increase; moreover, the turbine efficiency first decreases and then increases slightly after the pressure exceeds 1.5 MPa. The turbine efficiency decreases first and then increases and attains the minimum value at an inlet temperature of 100°C–105°C. When the flow rate is 0.82 m3/s, the speed reaches its maximum value of 28,000 r/min, and a maximum output power of 17.37 kW is generated. The maximum efficiency of the turbine is 0.885 and that of the system is 0.1625. The experimental data and design parameters of the turbine provide a reference for further design optimization.

Highlights

In recent years, with the increasing shortage of energy and an increasing focus on environmental protection, energy efficiency and clean energy have attracted considerable attention as research topics
In the experiments performed on the radial inflow turbine and Organic Rankine cycle (ORC) power generation system, the temperature reduction in the turbine, flow rate, output power, turbine efficiency and system thermal efficiency are analysed
The flow rate of R245fa is regulated through frequency conversion of the working fluid pump

Summary

Introduction

With the increasing shortage of energy and an increasing focus on environmental protection, energy efficiency and clean energy have attracted considerable attention as research topics. According to the specific experimental conditions, considering the thermal properties of R245fa (i.e. evaporation temperature of 90°C–125°C, condensation temperature of 25°C–40°C, inlet turbine superheat of 5°C, inlet pressure of 1.74 MPa, expansion ratio of 10, maximum flow rate of 3000 L/h and output power of 20 kW), a radial inflow turbine suitable for the ORC system is designed and tested in the ORC power generation system. In the experiments performed on the radial inflow turbine and ORC power generation system, the temperature reduction in the turbine, flow rate, output power, turbine efficiency and system thermal efficiency are analysed.

Results

Conclusion