Design and sensitivity analysis heat exchangers using finite element method

Among of adverse types of heat exchangers in the processing industries, shell and tube heat exchangers are the most common equipments found in oil refineries, petrochemical plants, and even nuclear systems. A shell and tube heat exchanger consist of at least tubes and shell around the tubes which two separated fluids withdifferent temperatures flow through them. There are loads of design parameters as well as operating conditions that affect on the performance of shell and tube heatexchanger. The main purpose of this study is to show the basic principles for setting up a heatexchanger model and the simultaneous effect of using disk and cu-o nanofluid, on thermal performance of heat exchanger has been investigated numerically, and hasbeen compared with results of the base fluid which flows in a plain tube. It was shown that using disk and tubes especially close to each other could increase theheat transfer or heat transfer coefficients more than 2 or 3 times. The results showed that the deviation between four models, in terms of bulk temperature, were quite similar for concentration of 1% to 4% of nano-particles. In spite of improvement in the heat transfer coefficients, it was shown that there were loads of pressure drop (approximately 10 times more than general and plain single phase fluids) when the fluid flow contained some nano-particles or close disks in the path of stream lines.Finally, to make a practical use of the suggested model in the industry as a CFD case study, the operating conditions imposed on one of the heat exchangers of the NGL 1000 unit in Iran was investigated. In the end, the results revealed that using 61 internal tubes can help achieve a standard heat performance by the model.

Keywords:

Heat Exchanger , CFD simulation , Baffle , Nano-fluid , Heat transfer coefficient , Passive and Active techniques