A new design of solar tower system amplified with a thermoelectric unit to produce distilled water and power

Abstract

• Suggest new solar tower system integrated with TEG unit and RO desalination system. • The suggested system energy efficiency is 3.7% higher than the conventional one. • The suggested system exergy efficiency is 5.28% higher than the conventional one. • The TEG employment leads to the increment of the output power about 941 kW. In this paper, a new design of a solar tower system boosted with a thermoelectric generator (TEG) for power generation and distilled water production, is proposed and investigated. The suggested system includes a solar tower unit with atmospheric air as heat transfer fluid, a helium Brayton cycle, two organic Rankin cycles (ORCs) with R-123 as working fluid, thermoelectric generator, and reverse osmosis (RO) desalination unit. The systems under investigation are the gas turbine-helium Brayton system (GT-HBS) as the primary system and the gas turbine-helium Brayton system integrated with TEG and RO (GT-HBS/TEG-RO) as the proposed system. A new aspect of the present work is the waste heat recovery using TEG modules to enhance the performance. Analysis indicates that the energy efficiency of GT-HBS and GT-HBS/TEG-RO systems is 43.88% and 62.44% and the exergy efficiency of GT-HBS/TEG-RO is 20.23 % higher than the GT-HBS. Additionally, the results show that employing TEGs in the primary system leads to the net output power, energy, and exergy efficiencies increment about 941 kW, 3.7%, and 5.28%, respectively. Based on the parametric analysis with an increasing inlet temperature of the gas turbine, the net output power, energy, and exergy efficiencies, and volume flow rate of the freshwater increase. Furthermore, the increment of the direct normal irradiation leads to the energy and exergy efficiencies enhancement. Besides, raising compressor pressure ratio, the net output power, energy, and exergy efficiencies first increase intensively then decrease gradually. The analysis of the new proposed system can be helpful to the system designers to create new system arrangements with higher performance.