A structure has been proposed in this paper for generating electricity from a waste heat recovery system using various experiences of research on the exploitation of thermoelectric effect, which allows the direct conversion of thermal energy into electrical energy. For this purpose, this paper has presented a new method for waste heat recovery in industry and converting it to electricity using a thermoelectric generator (TEG). The proposed system is a combination of a heat pipe and a thermoelectric generator. Indeed, the system consists of a thermoelectric generator (TEG) based on bismuth telluride (Bi2Te3), placed between two heat pipes. The proposed system is presented in two separate designs including a heat exchanger based on simple TEM1 and volumetric TEMs and has been implemented in MATLAB software. The simulation results show that the heat exchanger based on volumetric TEMs is 18% superior to the heat exchanger with simple TEM in producing electricity.

Gas turbines and solid oxide fuel cells can be combined in two different strategies to create a new high-efficiency hybrid system. In most hybrid systems, the fuel cell is located directly before the combustion chamber (pressurized type) or after the turbine (atmospheric type). The indirect hybrid system is another compound that has been less studied. In this system, the fuel cell and the gas turbine cycle are located in two separate cycles and heat exchange was done by a heat exchanger. The main purpose of this article is to compare the exergy and economic performance of direct and indirect hybrid systems. The results show that the direct hybrid system with pressurized fuel cell has better performance than the other two types of hybrid system. High electrical efficiency, low rate of irreversibility and pollution, and low cost of electricity generation, as well as appropriate cost of purchase, installation and system setup, are the characteristics of this type of hybrid systems. Analyzes of this study showed that the only positive feature of direct atmospheric fuel cell systems is high production capacity and indirect hybrid systems are less efficient than direct systems.