The hybrid method for the plate-finned tube
evaporator design process
Giuseppe Starace
1*
, Silvia Macchitella
2
, and Gianpiero Colangelo
2
1
LUM University, Department of Management, Finance and Technology, 70010 Casamassima (BA),
Italy
2
University of Salento, Department of Engineering for Innovation, 73100 Lecce, Italy
Abstract. The plate-finned tube evaporator performance, in terms of heat
transfer rate and refrigerant pressure drops, is influenced by several choices
done during the design process to be carried out complying with different
constraints. In this paper different refrigerant circuitry layout options
together with other parameters variations were investigated with the
purpose of supporting designers. Performance predictions were calculated
using the hybrid method as well as appropriate Performance Evaluation
Criteria (PEC) were adopted to select the best layout. The hybrid method
has been here revised and improved aiming at modelling heat exchangers
with an approach closer to real configurations that include complex circuit
layouts. The method was chosen as its main advantage (high accuracy in
the results with low computational costs) allowed to easily perform
operating conditions modifications to be compared.
1. Introduction
Good design and optimization processes are of great importance for heat exchangers in
order to reduce either production or operating costs. The design process itself should be
lean and accurate at the same time: often heat exchangers are oversized due to poor
accuracy in design process leading to higher production costs, while, on the other hand,
greater precision achieved with CFD approaches can severely slow down the optimization
process and still produce high design costs.
In order to save computational efforts, while getting high accuracy of the results, Starace et
al. [1] developed a powerful alternative design procedure, the hybrid method, using a multi-
scale approach starting from data sets coming from either numerical, analytical correlations
or from experimental investigations.
The hybrid method was successful implemented on compact cross-flow heat exchangers
using the results of CFD simulations performed by Carluccio et al. [2] on both the finned
surfaces of the HXs. Then, it was adapted to countercurrent evaporative condensers using
data coming from small-scale experimental investigations [3]. Results show how the
method is effective in predicting the outlet temperature and humidity with a deviation of
2.5% and 4% respectively compared to experimental data. The same method is also suitable
*
Corresponding author: starace@lum.it
© The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons
Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/).
E3S Web of Conferences 312, 03004 (2021) https://doi.org/10.1051/e3sconf/202131203004
76° Italian National Congress ATI