Title: Experimental Prediction of Heat Transfer Correlations in Heat Exchangers
Abstract: Heat exchangers is a broad term related to devices designed for exchanging heat between two or more fluids with different temperatures. In most cases, the fluids are separated by a heat-transfer surface. Heat exchangers can be classified in a number of ways, depending on their construction or on how the fluids move relative to each other through the device. The use of heat exchangers covers the following areas: the air conditioning, process, power, petroleum, transportation, refrigeration, cryogenic, heat recovery, and other industries applications. Common examples of heat exchangers in everyday use are air preheaters and conditioners, automobile radiators, condensers, evaporators, and coolers. (Kuppan, 2000). Many factors enter into the design of heat exchangers, including thermal analysis, size, weight, structural strength, pressure drop, and cost. Cost evaluation is obviously an optimization process dependent upon the other design parameters (Pitts & Sissom, 1998). Economics plays a key role in the design and selection of heat exchanger equipment, and the engineer should bear this in mind when taking up any new heat transfer design problem. The weight and size of heat exchangers are significant parameters in the overall application and thus may still be considered as economic variables (Holman, 2009; Shokouhmand et al., 2008; Rennie & Raghavan, 2006). Calculations of heat exchangers can be divided into two categories, namely, thermohydraulic and mechanical design calculations. The subject of thermal and hydraulic calculations is to determine heat-transfer rates, heat transfer area and pressure drops needed for equipment sizing. Mechanical design calculations are concerned with detailed equipment specifications, including stress analyses. Heat exchanger problems may also be considering as rating or design problems. In a rating problem, should be determined whether particular exchanger will perform a given heattransfer duty adequately. It is of no importance whether the exchanger physically exists or whether it is specified only on paper. In a design problem, one must determine the specifications for a heat exchanger that will handle a given heat-transfer duty. A rating problem also arises when it is desired to use an existing heat exchanger in a new or modified application (Serth, 2007). A particular application will dictate the rules that one must follow to obtain the best design commensurate with economic considerations, size, weight, etc. They all must bee considered in practice (Holman, 2009; Shokouhmand et al., 2008; Rennie & Raghavan, 2006).