Study On Seawater Desalination Technology Based On Cascade Utilization Of Waste Heat In Thermal Power Plant

In recent years,as an effective means to solve water shortage problem,low temperature multi-effect distillation(LT-MED)?Reverse osmosis(RO)desalination technologies has been developed rapidly,but high energy consumption is the bottleneck of its further application promotion.So how to reduce energy consumption of seawater desalination technology and ensure high production of fresh water at the same time,is an urgent needed problem to solve.Put forward two desalination system using coastal power plant waste heat: one is Hybrid MED/RO desalination system,the other one is a desalination system which use the power plant flue gas as heat source.According to a practical seawater desalination projects,calculate the fresh water production and performance ratio(PR).Compare the RO-MED system with MED-TVC system,and analyze the economic performance of two above seawater desalianation systems.Results shows that,the fresh water production of RO-MED system is much larger than MED-TVC system using steam source with the same temperature and flow rate,but the water production of RO-MED is smaller than MED-TVC in the MED part.On the premise of the same water quality,the water cost of MED and RO were compared,and it was found that MED system has the advantage.As for the LT-MED system with power plant flue gas as heat source,choosing the compact plate-fin heat exchanger as the first effect seawater evaporator.In this paper,the heat transfer and fluid flow characteristics of the corrugated fins heat exchangers are numerically investigated.The effect of wavy amplitude variation and fin spacing on the heat transfer pressure drop performance is analyzied.Result shows that,with the increase of fin spacing and amplitude,the turbulence in the corrugated channel is more fully developed,which shows the increase of j factor and f factor,and the result provide the reference for the next step plate-fin heat exchanger fin type selection.