The availability of reliable electricity and heat sources for community guarantees a better living environment in terms of education, healthcare and economy. Two main parameters should be considered in heat production which are the cost of this production and the performance of the devices used to produce this heat. In this work, a thermodynamic analysis based on energy and exergy analyses as well as economic analysis are presented to analyze the performance of parabolic trough solar collector (PTC). A multiobjective swarm optimization (MOPSO) technique is used to find out the maximum exergy efficiency and the minimum heat production cost of PTC. The optimum results show that the exergy efficiency, energy efficiency and heat cost are 29.22%, 35.55% and 0.0142 $/kWh. The effect of PTC geometrical parameters such as length, focal length, width and internal absorber diameter on the performance of PTC and heat production cost are investigated. Energy efficiencies of the system at different times during the day are calculated and they are in good agreement with the experimental results available in literature. The proposed system of PTC is located in Tehran, Iran.

Introduction

Solar energy is one of the abounded renewable energy resources distributed in the world. Utilization of solar energy can be used based on its application at low, intermediate and high temperature (Jebasingh and Herbert, 2016; Yousefi and Ehyaei, 2017). One of these applications is Concentrated Solar Power plant (CSP). CSP depends on the reflected sun ray from the concentrator to the receiver in order to increase the temperature of the working fluid (Jebasingh and Herbert, 2016; Yousefi and Ehyaei, 2017). There are two types of CSP which vary based on the shape of optical concentrator namely point or line focusing. Point focusing produces higher temperature than the line focusing and it requires two axis tacking. Both power tower and parabolic dish CSP are considered as point focusing, while Parabolic Trough (PT) and Fresnel CSP are considered as line focusing (Fuqiang et al., 2017). Parabolic trough concentrated solar power (PTCSP) can be integrated easily with conventional power plant such as steam turbine (Rankine cycle) or gas turbine (Brayton cycle). This integration is carried out to achieve higher integrated system efficiency at low environmental impact t (Jebasingh and Herbert, 2016; Yousefi and Ehyaei, 2017). There are many configurations of PTCSP used in power plants, these configurations vary based on many parameters such as type of integration, type of working fluid, thermal storage system, shape of receiver, types of tracking system and reflector, and receiver (absorber) materials (Ehyaei et al., 2019; Fern andez-García et al., 2010).