High efficiency condenser with compressor for multi-effect solar desalination

In the proposed Phase I program, Savengy Technologies, LLC and the University of Central Florida (UCF) will develop physics-based models and build a prototype with the goal of producing a reliable tool to design a commercially viable, energy efficient, low cost thermal desalination unit. This unit is especially suitable for people living in remote areas so that they can be self-sufficient and secure. Savengy Technologies, LLC proposes a novel solar powered cycle for co-production of electricity and potable water. The latter is based on multi-effect desalination (MED) with a compact condenser and a small vapor compressor. The vapor compressor is novel and is capable of minimizing the loss of latent heat which is critical to energy efficiency. MED can recover potable water from treated waste water, brackish water and sea water. This process has many advantages compared to other desalination processes such as reverse osmosis where many pre-treatment requirements are needed. Savengy already has a preliminary design for the full-scale unit and will finalize the design during the Phase I efforts. Savengy will also conduct experiment to realize small-scale water production and to show that the approach is scalable to the Phase II prototype. The proposed system can achieve acceptable cost (~$1/m3), as well as low energy requirements (<2 kWh/m3). The MED unit is transportable and compact. There is no fouling issue because the temperature of MED is less than 85oC. The proposed technology and systems are able to produce fresh water (<500 ppm total dissolved solids) from seawater (35,000 ppm total dissolved solids). In Phase II and beyond, Savengy will collaborate with their partners to design and build a thermal desalination system with a 1000 m3/day production rate of potable water, and pursue further investigations into scaling issues for a higher target. Key words: Compact condenser, multi-effect, solar desalination. Potential Commercial Applications and Anticipated Benefits A major thermal system company estimates sales revenues of $7M/y and licensing revenues of $100,000/y during the first 10 years of commercialization. Anticipated benefits are: - Improve the traditional MED efficiency by at least 10 fold. - Save 100% last stage MED steam energy. - Low cost of energy <2 kWh/m3. - Since it is powered by solar, no fuel is needed and there is no greenhouse gas emission.