Study On The Heat Transfer Characteristic Of The Capillary Heat Exchanger In The Shallows Near The Coast

The sea water source heat pump makes use of ocean resources, can save energy and protect environment and also has significant economic and environmental benefits. Looking for the heat exchange system that can be adapt to a variety of water and be with high heat transfer efficiency and low cost is the main problem in the applications of sea water source heat pump. At present the heat removal modes contain coast wells, casted heat exchanger and directly intake water, but thses several patterns are affected by the coastal soil, installation position and sea creatures, etc, can not meet our requiments. In engineering practice, the capillary heat exchanger is concerned by more and more professionals because of its huge heat exchange area and high heat transfer efficiency.This thesis proposes a new sea water source heat pump, using a network type capillary heat exchanger that is buried in the sand bed of sea bottom as a front end heat exchanger of the sea water source heat pump transfers heat to sand around the capillary heat exchanger. It can solve the problem of heat exchanger corrosion and high cost inherent, be not affected by geology, be good to energy-saving operation of heat pump and shorten the transportation distance. But its heat transfer characteristics is essential for system design and unit operation. The main contents are as follows:First determine the depth of constant temperature, the soil temperature at the depth with constant temperature, the soil in the sea-bed thermal parameters, the convective heat transfer coefficient between the heat medium in the capillary and the capillary inner wall of the heat exchanger, the convective heat transfer coefficient between the soil in the sea-bed and the underling seawater by literature consulting and other ways. Simplify the capillary heat transfer model and set up the capillary heat exchanger heat transfer mathematical model;Second according to the feasible layout plan, establish a 3D model by CFD numerical simulation software and confirm the boundary conditions of model. Based on the relevant thermal parameters that are acquired make the numerical simulation, obtain the inlet and outlet temperature distribution of the capillary heat exchanger under different buried depth and different layers;Finally process and analyze the numerical simulation results, evaluate the heat transfer characteristics of the capillary heat exchanger that is buried in the shallows near the coast, measure the application prospect of capillary heat transfer that is buried in the shallows near the coast as the front end heat exchanger of sea water source heat pump and optimize the capillary heat exchanger.