Theoretical analysis on absorption heat transformers boosted multi-effect distillation system for ocean thermal energy conversion

The utilization of renewable energy sources enables the reduction of thermal and electrical energy consumption in the desalination process, thereby decreasing overall desalination costs. Due to its consistent quality and large reserves, ocean thermal energy shows promise as an effective solution for powering multiple effect distillation processes. This paper introduces absorption heat transformers boosted ejection system for multi-effect distillation, driven by ocean thermal energy. This system enables steam of ejector primary flow up to 160 degrees C, subsequently driving the multi-effect distillation system for desalination. The proposed system exhibits advantages of low electricity consumption, high productivity, and superior economic and thermal efficiency. Under the typical working condition and 370m3/s cold seawater intake flow rate, this system can produce up to 80,985 m3/day of freshwater, with a specific work consumption of 2.72kWh/m3 and a levelized cost of water of only 0.89$/m3. When the ejector operates at a mainstream temperature of 160 degrees C and ejection ratio of 0.35, the levelized cost of water can achieve a level of 0.5$/m3. Compared with other ocean thermal energy-based seawater desalination systems, the proposed system reduces water production energy consumption by 53 % and lowers the levelized cost of water by 50 %, demonstrating outstanding potential for low-cost operation.