Performance optimization and design of organic Rankine cycle coupled  with parabolic trough solar collector for small scale power generation: (A case of Dek island, lake Tana)

Natnael, Abebe

dc.contributor.author	Natnael, Abebe
dc.date.accessioned	2022-02-21T11:47:07Z
dc.date.available	2022-02-21T11:47:07Z
dc.date.issued	2021-06
dc.identifier.uri	http://ir.bdu.edu.et/handle/123456789/13022
dc.description.abstract	Access to modern energy sources is critical for economic development and improved living conditions. Solar thermal energy for electricity generation is a clean and sustainable solution to meet our community's growing energy needs. In the power block of concentrated solar power (CSP) systems, the traditional Rankine cycle has been used. However, in order to be competitive and efficient, this technique requires a minimum power of 10 MW and high collector temperatures, necessitating a huge solar field area. Because, the traditional Rankine cycle needs high temperature and pressure to have high thermal efficiency. By scaling up the zero/near-zero thermal efficiency of the traditional Rankine cycle using organic working fluids at lower and medium temperature, the solar organic Rankine cycle system could be one of the multi -purpose technologies for providing power and heat in rural households. In this study, the solar organic Rankine cycle, along with a parabolic trough collector, was designed and optimized for small-scale power generation a case of Dek Island, Lake Tana. The solar radiation data of the typical meteorological year (TMY) was taken from the PVGIS generated between 2007 and 2016 with annual daily average beam radiation of 736 �/� 2 . The interest area's household and institution power consumption were estimated using basic electrical appliances, and the net estimated design power output was 5.2 MW. To analyze and optimize the mathematical model of the parabolic trough collector, a MATLAB code was developed. The aperture width, receiver diameter, air gap thickness, fluid inlet temperature, and mass flow rate were the important parameters in the optimization procedure. With an aperture width of 7 m, a receiver diameter of 20 cm, an air gap thickness of 5 mm, and a flow velocity of 1 kg/s, the maximum collector thermal efficiency of 77 % was achieved. The two -tank direct storage mechanism was included for reliable power generation with a 15 -hour capacity considering 9-hour active operations of the collector. The collector was tested to validate the mathematical model implemented in the MATLAB code. As observed in the result, the design was effective except some intermittence due to manual tracking mechanisms. Engineering equation solver, EES, was used to analyze the thermodynamic analysis of the power block with organic fluid. The candidates of three working fluids, (Benzene, Cyclohexane and Methanol) were chosen. The power block was investigated in two configurations: basic ORC and ORC with recuperator. Among the other candidates of a working fluid, Methanol exhibited the highest thermal efficiency. The maximum thermal efficiency obtained was 25.53 % and 32.54 % with basic ORC and ORC with recuperator, respectively. The system efficiency of the SORC is product of the collector and power block efficiency which is 19.5 % and 25.06 % with basic ORC and ORC with recuperator, respectively. Therefore, Methanol, fluids with higher thermal efficiency and lower mass flow rate was selected as a working fluid of a system.	en_US
dc.language.iso	en_US	en_US
dc.subject	ENERGY CENTER	en_US
dc.title	Performance optimization and design of organic Rankine cycle coupled with parabolic trough solar collector for small scale power generation: (A case of Dek island, lake Tana)	en_US
dc.type	Thesis	en_US