José Maria Saíz-Jabardo

Thermal Performance of Multipass Parallel and Counter-Cross-Flow Heat Exchangers

Univ Sao Paulo, Escola Engn Sao Carlos, Dept Engn Mecan, BR-13566590 Sao Carlos, SP, Brazil

Effectiveness - NTU data and analysis for air conditioning and refrigeration air coils

A simulation program based on a control volume analysis has been used in the evaluation of the (e, NTU) relationship for coils of complex geometry and flow arrangement. The simulation program has been evaluated through simple geometry and flow arrangement coils. The program results compare very well with correlations for simple cross flow coils, and a number of rows up to four. It has also been determined that closed form correlations developed for coils of an infinite number of tube rows are inadequate for those with number of rows in the range between 5 and 10. In addition, it has been found that closed form (e, NTU) correlations for cross flow coils with the same tube arrangement and number of rows might lead to inaccuracies higher than 10% in the evaluation of the effectiveness of coils of complex flow arrangement.

Numerical Results and Discussions

In the previous sections fundamentals of the HETE code were introduced. The objective of this section is to demonstrate the capabilities of the code through several nonstandard applications which will allow the reader to assess its potential. These applications will be introduced as an overview of several journal papers published by the authors namely Navarro and Cabezas-Gomez (2005), Cabezas-Gomez et al. (2007), Cabezas-Gomez et al. (2009), and Cabezas-Gomez et al. (2012).

Heat Exchanger Effectiveness Data for Several Configurations

Heat exchanger effectiveness for 35 cross-flow configurations with important industrial applications is presented in this chapter in both plot and table forms. Both versions for the Cmin fluid are included: (a) for the Cold (external, air); and (b) for the hot (in-tube) fluid. Effectiveness is given in terms of the heat capacity ratio, C * , and the NTU group for the following ranges: 0 ≤ C * ≤ 1.0 and 0 ≤ NTU ≤ 10.0. All the configuration input files are available in the internet site address: http://extras.springer.com. Details of most of them can be found in Chap. 6.