Uncertainty analysis, which is frequently used in conjunction with experimentation, is adapted to the analysis of cross-flow heat exchanger performance predictions (rating, pressure drops, and fluid stream exit temperatures). The basic tools of uncertainty analysis are reviewed, and uncertainty analysis for cross-flow heat exchanger performance predictions is developed and illustrated with a detailed example. The use of uncertainty analysis in cross-flow heat exchanger performance predictions permits error bounds to be placed on predicted performance parameters and gives insight into the fidelity of such predictions. Moreover, uncertainty analysis gives considerable insight into the important physical variables and provides a reliable alternative to ad-hoc overspecification of fouling factors. Uncertainty analysis is shown to be a viable paradigm for cross-flow heat exchanger analysis.

The application of uncertainty analysis to cross-flow heat exchanger performance predictions

Methods to perform thermal performance tests and analyze the results for heat exchangers in industrial process streams are discussed. Industrial test practices and operating conditions are compared with experimental methods. A thorough review of sources of error and their contribution to overall test uncertainty is described. The analysis includes methods to estimate the uncertainty of predicted performance based on test data measured at different operating conditions. It is concluded that accurate industrial tests (as accurate as laboratory tests) are performed infrequently because the cost of temperature and flow instruments is high and it is difficult to control or adjust process conditions as needed. To overcome these limitations, future work is needed to implement cost effective smart sensors and online analysis methods along with continuing development of test standards. This chapter is of interest to personnel responsible for thermal testing of industrial heat exchangers and those implementing performance enhancements in industrial processes.

D. M. Evans

Papers

The role of probable uncertainty in the design and testing of compact heat exchangers