Numerical Analysis of Plate Heat Exchanger Performance in Co-Current Fluid Flow Configuration

For many industrial applications plate heat exchangers are demonstrating a large superiority over the other types of heat exchangers. The efficiency of such a device depends on numerous factors the effect of which needs to be analysed and accurately evaluated. In this paper we present a theoretical analysis of a cocurrent plate heat exchanger and the results of its numerical simulation. Knowing the hot and the cold fluid streams inlet temperatures, the respective heat capacities mCp and the value of the overall heat transfer coefficient, a 1-D mathematical model based on the steady flow energy balance for a differential length of the device is developed resulting in a set of N first order differential equations with boundary conditions where N is the number of channels.For specific heat exchanger geometry and operational parameters, the problem is numerically solved using the shooting method. The simulation allows the prediction of the temperature map in the heat exchanger and hence, the evaluation of its performances. A parametric analysis is performed to evaluate the influence of the R-parameter on the e-NTU values. For practical purposes effectiveness-NTU graphs are elaborated for specific heat exchanger geometry and different operating conditions.




References:
[1] J. A. W. Gut, J. M. Pinto, Modeling of plate heat exchangers with
generalized configurations, International journal of heat and mass
transfer,, 2003, pp. 2571-2585.
[2] R. K. Shah, W. W. Focke, Plate heat exchangers and their design
theory, Heat transfer Equipment Design, Hemisphere, New York, 1988,
pp. 227-254.
[3] T. Zaleski, K. Klepacka, Approximate method of solving equations for
plate heat exchangers, International journal of heat and mass transfer,
vol. 35, n┬░5 , pp. 1125-1130.
[4] J. Wolf, General solution of the equations of parallel flow multichannel
heat exchanger, International of heat and mass transfer, 1964, n┬░7, pp.
901-919.
[5] T. Zaleski, A general mathematical model of parallel flow multichannel
heat exchangers and analysis of its properties, Chem. Engng. Sci., 1984,
39, 1251.
[6] F. Incropera, D. DE Witt, Fundamentals of heat and mass transfer, John
Wiley & Sons, 3rd Ed, Singapore.
[7] W. M. Kays, A. L. London, 1964, Compact heat exchangers, MacGraw-
Hill, 2sd Ed New York.
[8] W. H. Press, B. P. Flannery, S. A. Teukolsky, W. T. Vetterling, 1992,
Numerical Recipes in Fortran 77, Cambridge University Press, 2sd Ed.