Low Cost, Low Energy Concentrate Water Desalination using Heat Recuperative Solar Still with Concentrating Solar Technology

Transcription

1 Cooperative Agreement Project between New Mexico State University and U.S. Bureau of Reclamation Low Cost, Low Energy Concentrate Water Desalination using Heat Recuperative with Concentrating Solar Technology Sarada Kuravi (MAE), Pei Xu (CE), Krishna Kota (MAE), Huiyao Wang (CURRL), Young Ho Park (MAE) New Mexico State University Project Period: May 1, 2017 April 30, 2019

2 Goal, Objectives Explore and develop innovative solar collection and heat transport/management approaches for realizing a scalable, low cost, low energy solar still with rapid desalination capability for RO concentrate management and energy recovery

3 Goal, Objectives Explore and develop innovative solar collection and heat transport/management approaches for realizing a scalable, low cost, low energy solar still with rapid desalination capability for RO concentrate management and energy recovery 1. Solar Insolation Key Thermal Enhancements of a Still Technology Flat plate collectors Parabolic trough Solar pond Inverted absorber Tubular evacuated tube type Fresnel lens Results Distillate yield: 24% to 200% (day) 300% (night) Efficiency increased Temperatures 50 0 C to boiling temperatures Reflectors increase productivity by % in winter

4 Goal, Objectives Explore and develop innovative solar collection and heat transport/management approaches for realizing a scalable, low cost, low energy solar still with rapid desalination capability for RO concentrate management and energy recovery Key Thermal Enhancements of a Still 2. Evaporation & Condensation Technology Basin: wicks, weir-type, pebbles, baffle plates, sponges, air bubbles, heat exchangers Glass Cover Cooling: wind turbine assisted, glass coolant (water), fan, sprinklers, roof type, tilting Results Overall efficiency is increased distillate output increases from 34% to 42% by cover cooling

5 Goal, Objectives Explore and develop innovative solar collection and heat transport/management approaches for realizing a scalable, low cost, low energy solar still with rapid desalination capability for RO concentrate management and energy recovery Key Thermal Enhancements of a Still 3. Heat recovery/ Storage Technology Part of basin Heat sink Results Productivity increased from 62% to 162%

6 Goal, Objectives Explore and develop innovative solar collection and heat transport/management approaches for realizing a scalable, low cost, low energy solar still with rapid desalination capability for RO concentrate management and energy recovery Research Objectives Increase still productivity by 500% Amplify solar insolation to the still to enable boiling (rapid) instead of evaporation (slow) Enhance the phase change processes i.e., boiling rate in the basin and the condensation rate on the glass cover Make the technology based only on renewable energy for reducing costs Build a laboratory-scale prototype at NMSU Perform economic analysis

7 Approach, Timeline Timeline Year Month Task 1 Task 2 Task 3 Task 4 Task 5

8 Approach Solar Enhancement using Power Tower with Centralized Mirror Solar Enhancement using Fresnel Lens Fresnel Lens

9 Progress Task I: Solar Enhancement and Still design Literature review is complete Initial design of still was fabricated and tested Tests were performed with and without Fresnel lens Currently, new design is being considered Expt. # Fresnel Lens Average Ambient Temp. ( 0 C) Average Glass Temp. ( 0 C) Water output in 3 hours 1 No ml 2 No ml 3 No ml 4 Yes ml 5 Yes ml

10 Progress Task I: Solar Enhancement and Still design Modifications in the Fresnel lens height from the Still will be considered next for the experiments Based on 2D analysis, a concave mirror will be used as centralized mirror 3D analysis will be performed in the future to design the mirror arrangement

11 Progress Task II: Phase Change Enhancement Literature review is complete A theoretical model is being developed to analyze the thermal processes Hydrophilic surfaces on aluminum surfaces were prepared using a novel approach The contact angle was found to be zero, in comparison to degrees contact angle for polished aluminum 8-10 times more spreading was observed Studies show low contact angles and high spreading to enhance boiling heat transfer Other Items A review article is planned to be submitted to the journal Water by the end of this year. Capstone teams are working on this project mainly on designing and testing the solar Still. was video taped by PBS TV on July 14 as part of their Informed series on ongoing activities at NMSU College of Engineering.