ANALYSIS OF EVACUATED ANNULUS TUBE COLLECTOR ASSISTED SOLAR DESALTIFICATION SYSTEM

Abstract

Pure water is one of the basic elements required for continuing healthy life on the Earth, whereas the adverse situations due to water stress faced by human beings more or less all over the globe. As the large scale industrialization, rapid escalation in agriculture and population all over the world create more difficult situations for freshwater demand and supply chain and hence many of the people are forced to use contaminated, brackish, or salty water that cause various health related problems. To tackle and overcome the challenges related to water stress, the use of renewable energy (solar energy) in solar desaltification systems (eco friendly, economical and self sustainable technology of water purification) may one of the best solutions to treat the brackish/saline water into potable one. Solar desaltification is the process of receiving potable water against the brackish water by harnessing solar energy through solar desaltification systems which replicates the natural hydrological succession with a difference of closed cyclic operation in a confined chamber. In the present study, a novel design of solar desaltification systems (SDS) with evacuated annulus tube collector (EATC) augmented unique combination of modified compound parabolic concentrators (MCPC) has been analyzed for Techno-EnvironEconomic-Energy-Exergy-Matrices observations under the specific meteorological conditions of New Delhi, India. Two different models (a) Evacuated annulus tube collector assisted single slope solar desaltification system, (b) Evacuated annulus tube collector assisted double slope solar desaltification system, have been analyzed in the proposed work of research. The current approach emphasizes the utility of EATC-MCPC that effectively improves the solar absorbing performance of the irradiated solar energy uniformly through its periphery, as well as enhancing the thermo siphons working loom appreciably than the conventional applications of EATCs. The proposed system is being optimized to get the maximum possible basin water temperature as ~99.5°C for the larger water depth (0.16m) at the same orientation of both, SDS top cover and EATC (30°). The developed thermal model and respective characteristic equations have been utilized to analyze the proposed systems. The analysis is primed on the basis of

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performance evaluation of the system directly or indirectly that depends on the productivity of potable water, energy, exergy efficiencies, energy-exergy metrics, various economic analyses of the system, and also techno-eco impact to the environment. The performances of the proposed systems are being compared with the former researches in the influence of different governing parameters. The system’s energy-exergy (kWh), efficiency (%), mass flow rate (kg/hr), yield cost ($/kg), pollutants mitigate (ton), production cost ($) with respect to the energy input (kWh), exergo-economic factor, environmental cost ($), payout time, total annual cost of the establishments ($), and life cycle conversion efficiencies are computed under the different variable parameters such as solar intensity, ambient temperature, water depth, and number of EATCs to depict the worthy performances for the optimized integral combination of the proposed systems. It has been observed that the double slope solar desaltification system produces greater yield at moderate circulation rate (thermo siphon) of water. And, this system is much better in overall terms of performance except energy-exergy efficiency than the single slope solar desaltification system under the same design parameters and climatic conditions. The establishment cost of the system is quite low for both the systems. Also, the productivity for both the system's are found more than 100% that depict the systems as appreciably feasible. The noticeable yield output at low production cost, environmental revenue credits, high mitigation, and low pay-off time makes the system compatibly sustainable and feasible with smaller and effective collector areas for the respective solar irradiations. The overall work has been intensively analyzed to get the responsible, and system effective results which are nourished with detailed result discussion and conclusions with future recommendations that may enlighten the researchers to motivate for the additional possible developments in this field for the betterment to the society, environment, and the sustainable growth of human beings ecologically.