A Study On Performance Of A Heat Pump Assisted Dewvaporation Seawater Desalination System

Dewvaporation desalination technology is a new type of seawater desalination technology.It uses seawater to obtain fresh water by humidification and dehumidification the air,and can directly transfer the latent heat of condensation of water vapor to the evaporation side,to provide heat for the evaporation process,suitable for small and scattered remote areas to produce fresh water.This paper attempts to replace the secondary desalination system in the ordinary dew-point evaporative seawater desalination system with the heat pump system.A dewvaporation seawater desalination system based on shell and tube heat exchanger is designed under given typical conditions.According to two different schemes,the mathematical model of the desalination system was established,and the performance parameters of the two systems were simulated by MATLAB,and the rule of the change of each performance parameter of the system with the operating conditions was obtained under different operating conditions.On this basis,the performance parameters of ordinary desalination system and heat pump assisted desalination system are compared,and the reasons affecting the parameter changes are analyzed.The results show that under different operating conditions,the fresh water output of the heat pump assisted dew-point evaporative seawater desalination system is 14.3% to 16% higher than that of the ordinary system,and the water production ratio of the heat pump system is 0.27?3.03 higher than that of the ordinary system.When the seawater flow increased,the fresh water production and water production ratio of the system increased first and then decreased.When the carrier gas flow increased,the fresh water production and water production ratio of the system gradually increased and tended to level off.As the temperature increases,the fresh water production of the system increases gradually.When the seawater temperature is about 75?,the maximum water-making ratio can be achieved by using a smaller inlet carrier gas on the condensing side to raise the temperature.