Numerical Study on Natural Vacuum Solar Desalination System with Varying Heat Source Temperature

1st Annual Applied Science and Engineering Conference

工业技术;自然科学

Ambarita, H.^1

Sustainable Energy Research Centre, Faculty of Engineering University of Sumatera Utara, Jl. Almamater Kampus USU, Medan

20155, Indonesia^1

关键词: Constant temperature;    Fresh water production;    Heat source temperatures;    Low grade heat sources;    Solar desalination systems;    Vacuum desalination;    Variable temperature;    Varying temperature;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/180/1/012024/pdf
DOI  :  10.1088/1757-899X/180/1/012024

来源: IOP

【 摘 要 】

A natural vacuum desalination unit with varying low grade heat source temperature is investigated numerically. The objective is to explore the effects of the variable temperature of the low grade heat source on performances and characteristics of the desalination unit. The specifications of the desalination unit are naturally vacuumed with surface area of seawater in evaporator and heating coil are 0.2 m2and 0.188 m2, respectively. Temperature of the heating coil is simulated based on the solar radiation in the Medan city. A program to solve the governing equations in forward time step marching technique is developed. Temperature of the evaporator, fresh water production rate, and thermal efficiency of the desalination unit are analysed. Simulation is performed for 9 hours, it starts from 8.00 and finishes at 17.00 of local time. The results show that, the desalination unit with operation time of 9 hours can produce 5.705 L of freshwater and thermal efficiency is 81.8 %. This reveals that varying temperature of the heat source of natural vacuum desalination unit shows better performance in comparison with constant temperature of the heat source.