Heat‐Exchange Technology, Heat Transfer

Abstract

In order to select a proper heat exchanger for a given application, various factors such as pressure, temperature, size, fouling factor, and the use of toxic or corrosive fluids must be considered. These pressure and temperature requirements mainly dictate the type of heat exchanger selected. In general, for high pressures and temperatures, tubular heat exchangers that conform to safety regulations and manufacturing codes are used. For moderate pressures, small but very efficient plate heat exchangers can be employed. There are three heat‐transfer modes, ie, conduction, convection, and radiation, each of which may play a role in the selection of a heat exchanger for a particular application. The basic design principles of heat exchangers are also important, as are the analysis methods employed to determine the right size heat exchanger. The shell‐and‐tube exchanger is the workhorse of power, chemical, refining, and other industries. Plate heat exchangers are used as an alternative in relatively low temperature and pressure applications involving liquids and two‐phase flows. Cold‐plate heat exchangers are used for electronics cooling applications. Heat exchangers are used whenever energy has to be transferred, and the proper design and use of heat exchangers are vitally important for efficient operation of an industrial system, for energy conservation, and ultimately for the protection of the environment. There are numerous design and operating problems originating from a lack of understanding of basic flows and heat‐transfer phenomena such as flow distribution in manifolds, flow‐induced vibration in two‐phase flows, heat‐transfer enhancement, fouling, etc. In order to help companies and organizations overcome problems associated with heat exchangers, for example, Heat Transfer Research Inc. (HTRI) (U.S) and the Heat Transfer and Fluid Flow Service (HTFS) (UK) provide results of heat‐transfer and fluid‐flow research, design methods, supporting computer programs, and proprietary equipment testing.