A General Approach in Optimization of Heat Exchangers by Bio-Inspired Artificial Intelligence Methods

Jaroslaw Krzywanski

doi:10.3390/en12234441

Abstract

The paper introduces the artificial intelligence (AI) approach as a general method for the design and optimization study of heat exchangers. Genetic Algorithms (GA) and Artificial Neural Networks (ANN) are applied in the paper. An AGENN model, combining Genetic Algorithms with Artificial Neural Networks, was developed and validated against the desired data on a large falling film evaporator. A broad range of operating conditions and geometric configurations are considered in the study. Four kinds of tubes are deliberated, including plain and enhanced tubes. Different tube pass arrangements, i.e., top-to-bottom, bottom-to-top, and side-by-side, are discussed. Finally, the effects of liquid refrigerant mass flow rate, as well as the number of flooded tubes on the performance of the evaporator, are analyzed. The total heat transfer rate of the evaporator, predicted by the model, is in good agreement with the desired data; the maximum error is lower than ±3%. The highest heat transfer rate of the evaporator is 1140.01 kW and corresponds to Turbo EHP tubes, and bottom-to-top tubes pass arrangements, which guarantee the best thermal energy conversion. The presented approach can be referred to as a complementary technique in heat exchanger design procedures, besides the common rating and sizing tasks. It is an effective and alternative method for the existing approaches, considering the complexity of analytical and numerical techniques as well as the high costs of experiments.

Highlights

Heat exchangers are devices where the conversion of thermal energy between two or more fluids at different temperatures takes place
An artificial neural network (ANN) operation depends on its topology, including the number of layers and neurons in each layer, where the number of input and output neurons is equal to the number of inputs and outputs, respectively
The following factors are taken into account: the tag kind of tubes (KT) expressing the kind of tube

Summary

Introduction

Heat exchangers are devices where the conversion of thermal energy between two or more fluids at different temperatures takes place. A broad spectrum of different heat exchanger configurations in various applications, as well as their design and operational criteria, can be found in the literature. In regenerators (storage-type heat exchangers), the thermal energy of the hot fluid is stored in a flow passage (matrix) occupied first by the flowing hot fluid and extracted by the cold fluid during its flow through the same passage at the later time. In direct-contact-type heat exchangers, heat is transferred through the interface between hot and cold fluids, whereas in indirect-contact-type ones (transmural heat exchangers) the streams are two immiscible liquids with a wall between them [2]

Methods

Results

Conclusion