| As an important lifeline of national economy, energy is used in a low efficient, at the same time,we are terrible shortage of energy. China Energy Research Society recently released a data:in 2010, China's consumption of primary energy was 3.25 billion tons of standard coal, an increase of 6%, the consumption of crude oil, natural gas and electricity were all increased by more than 10%, as the largest consumption of coal, steel, iron ore, alumina, copper, cement in the world, China has become a major energy consumer.As an important heat transfer equipment, shell and tube heat exchangers are widely used in petroleum, chemical, steel, electricity and other fields, heat exchanger is the key device to achieving energy saving mission, so the development and promotion heat transfer enhancement and clean technology against the heat exchangers is very important.First in this thesis we will introduce the variety methods of heat transfer enhancement in exchanger tube recently in the world to compare the advantages and disadvantages of them, than we propose an autorotational rotor, which is a heat transfer enhancement and self-cleaning device, we compare the rotor with the twisted tape, which is also an online self-cleaning device with the ability of heat transfer enhancement. In this paper we use CFD numerical simulation software to analyze the axial velocity of the particle in the flow field, and the effect on the laminar boundary layer when insert is put in the tube.We use this software to analyse the heat transfer performance by comparing variety lead of rotors and the twisted tape. Then on the basis of simulation conditions, we do experiment on each heat transfer component to prove the performance of heat transfer and pressure drop, identify the relationship between Nu. and Re., the f. and Re., and utilizing the PEC criteria widely used in project evaluation to screen out the best economy one in order to guide industrial applications. |
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