## 1 Introduction  
Currently, energy shortage and environmental pollution are becoming increasingly prominent. There is a large amount of low-grade heat energy, which accounts for more than 50% of the total energy produced worldwide [1; 2; 3; 4]. Considerable studies have been conducted regarding the recovery of low-grade heat energy. Organic Rankine Cycle (ORC) has exhibited high potential in terms of the utilization of low-grade heat energy conversion to electricity [5; 6]. In the past few years, many studies have been conducted in the ORC research fields, mainly focusing on working fluid selection, system design optimization, and expander technologies [7; 8; 9]. [PERSON] et al. [10] investigated the impacts of working fluid type and critical properties on ORC system design and concluded that fluorocarbons and low critical temperature hydrocarbons are more suitable for low-temperature ORC applications, while siloxanes and high critical temperature hydrocarbons are more suitable for high-temperature ORC applications. [PERSON] et al. [11] conducted a thermodynamic and thermoeconomic study of an ORC system. Multi-objective optimization of the cycle was carried out with four working fluids, and they found that toluene is the best working fluid, producing 9.76% additional power for the solid waste power plant. [PERSON] et al. [12] established a multi-objective optimization model of an ORC system for maximizing net power output and minimizing total investment cost, and the model was solved using a genetic algorithm with six working fluids. R245 fa, whose optimized evaporation pressure is in the range of 1.1 Mpa-2.1 Mpa and optimized condensation temperature almost keeps a constant value of 298.15 K, is considered as the optimal working fluid. [PERSON] et al. [13] proposed a thermo-economic-environmental optimization model integrating environmental impact and thermo-economic performance. A case study with R134a as the working fluid was conducted, and the results showed that a trade-off between the environmental objective and the thermo-economic objective can be achieved via multi-objective optimization. [PERSON] et al. [14] conducted energy, exergy, and exergoeconomic analyses of an ORC unit that was coupled with a waste-to-heat plant, and found that R123 achieved the best performance for the integrated system. [PERSON] et al. [15] established a multi-objective optimization model of an ORC system with electric efficiency and the overall area of the heat exchangers as objective functions; in the Pareto optimal front, electric efficiency is in the range of 14.1-18.9% and the overall area of the heat exchangers rangers from 446 m\({}^{2}\) to 1079 m\({}^{2}\). Radial-inflow turbine is one of the key components of the ORC system, and its efficiency affects the system performance directly [16; 17; 18]. In most of the ORC theoretical analysis studies, radial-inflow turbine efficiency is assumed to be a constant value for different working fluids and operating conditions, which may lead to errors in theoretical results including working fluid selection and system parameter optimization. [PERSON] et al. [19] proposed an optimized method for the ORC system based on the radial-inflow turbine, and constant expander efficiency was replaced with predicted expander efficiency. They found that there is a considerable difference in turbine efficiency for different operating conditions. [PERSON] et al. [20] combined the ORC thermodynamic model with a radial-inflow turbine design procedure. The firefly algorithm was used to optimize the thermal efficiency and the size parameter. [PERSON] et al. [21] proposed an optimized coupling model of an ORC system with a radial-inflow turbine and investigated the impact of heat source outlet temperature on turbine efficiency and system performance. There are very limited investigations that focus on the influence of turbine efficiency selection on the thermodynamic and economic performance of the ORC system simultaneously.