Based on the remarkable heat transfer performance of heat pipe (HP) and great specific surface area of small diameter droplets

HP and spray technologies are used in a novel single stage vacuum evaporator. And man-made seawater with 3% saltness is tested. Parameters affecting the performance such as temperature of cold source and heat source

spray temperature and spray flow are investigated. The result shows that the maximum heat flux of evaporator bland plate is 32 W·cm-2. HPs absorb energy from low grade heat source between 40 to 80℃

and then transfer the energy to the droplets already flashed to keep or even increase the degree of superheat while evaporate. Thus

this method can significantly improve the water separation rate (quality of condensed water/quality of dilute solution ×100%). The initial superheat degree is replaced by temperature of cold source and heat source as the major factor on separating effect. The control of separation rate can be realized through adjusting the parameters. Therefore

this method has important implications for effective utilization of lower grade heat source

gaining brine and promoting the fresh water production unit volume and adaptability to variable load in desalination project.