Design Of Low-temperature And Twoeffect Desalination Equipment Of Heat Pipe Type

A low-temperature and two-effect desalination equipment of heat pipe type is developed to solve the lack of fresh water in oceangoing ships, islands and coastal areas. Based on the distillation desalination technology, the device not only combines heat pipe exchanger with low-grade waste heat, but also utilize the falling film evaporation and two-effect evaporation technology, which greatly improving the heat efficiency. In this paper, process and equipment design, numerical simulation and experimental method is used to design the device. The main contents included:Confirm the process system of the desalination device and design its process.Under the supply of the low quality of heat, material balance, heat balance and heat transfer are calculated to ensure its continuous and stable production of fresh water.Then, design the parts of the equipment on the basis of process calculation.The device of liquid distribution and falling film evaporation is the key component in this equipment. The rationality of the structure and the uniformity of the distribution will have an impact on its stability of the film and efficiency of mass and heat transfer directly, which will influence service life and production capacity furtherly. Therefore, the key parameters in the structure of liquid distributor of vertical tube, flow process of falling film and uniform film distribution, are simulated in this article. Based on the design of structure, VOF method in FLUENT software is used to establish the two phase flow model of falling film flow outside the vertical heat pipe.The flow pattern and velocity distribution of the film are analyzed to find out the gap of uniform film and the flow rate of the best heat transfer.For confirming and correcting the data, test platform is set up, including single tube falling film test, 5 tube falling film test and small desalination device. The research on the best falling film gap and corresponding flow, verify the integrity of the device and the feasibility of the falling film system. This development provides the basis for the further design of the device.