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

Abstract

A thorough study of the thermal performance of multipass parallel cross-flow and counter-cross-flow heat exchangers has been carried out by applying a new numerical procedure. According to this procedure, the heat exchanger is discretized into small elements following the tube-side fluid circuits. Each element is itself a one-pass mixed-unmixed cross-flow heat exchanger. Simulated results have been validated through comparisons to results from analytical solutions for one- to four-pass, parallel cross-flow and counter-cross-flow arrangements. Very accurate results have been obtained over wide ranges of NTU (number of transfer units) and C* (heat capacity rate ratio) values. New effectiveness data for the aforementioned configurations and a higher number of tube passes is presented along with data for a complex flow configuration proposed elsewhere. The proposed procedure constitutes a useful research tool both for theoretical and experimental studies of cross-flow heat exchangers thermal performance.

Air-side performance of serrated welded spiral fin-and-tube heat exchangers

“…The e-NTU relationships for multipass parallel cross-flow and multipass counter cross-flow configuration are available from [17][18][19], as shown in Eqs. (2) and (3): For multipass counter cross-flow with N row = 2:…”

Thermal characterization of a cross-flow heat exchanger with a new flow arrangement

“…The computation of the important parameters, thermal effectiveness, heat exchanger efficiency and entropy generation, employs the approach delineated in [7,8]. The procedure consists of a sequence of three basic steps: (i) division of the heat exchanger in a finite number of three-dimensional control volumes or elements, each element being itself a mixed-unmixed cross-flow heat exchanger; (ii) solution of the set of governing equations for each element; and (iii) step-by-step solution of the governing equations of subsequent elements along each circuit of the in-tube fluid.…”

“…9(d) of this reference) was performed. In addition, Cabezas-Gó mez et al [8] have shown that the thermal effectiveness of the complex flow arrangement is higher than that of a four-pass counter-cross-flow heat exchanger with higher values of C * and NTU. However, this result is not suitable to the lower range of C * and NTU, because in this range an opposite trend has been found.…”

“…The thermal effectiveness, the heat exchanger efficiency and the entropy generation in both cross-flow heat exchanger configurations have been computed by applying a recently developed computational procedure described in Navarro and Cabezas-Gó mez [7] and Cabezas-Gó mez et al [8]. In the latter reference, a comprehensive study of the cross-flow heat exchanger flow arrangement proposed by Guo et al [2], (refer to Fig.…”

Performance of a serpentine heat exchanger: Part I – Effectiveness and heat transfer characteristics

“…Park and Hrnjak [6] investigated the effect of heat conduction through fins on the capacity of a serpentine gas cooler. Cabezas-Gomez et al [7] proposed a new procedure to evaluate the e-Ntu relation of parallel and counter-cross-flow heat exchangers. Dong et al [8] measured the heat transfer and friction data of flat-tube heat exchangers with wavy fins.…”