Application of an improved parameter estimation approach to characterize enhanced heat exchangers

Pamela Vocale*, Fabio Bozzoli, Andrea Mocerino, Kristina Navickaitė, Sara Rainieri

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The main goals of this paper are twofold: to provide an improved parameter estimation procedure that enables the accurate evaluation of heat transfer correlations for the Nusselt number and to present a new procedure for identifying the presence of transition in the flow regime.

In the first goal, it needs to be pointed out that although this kind of approach is based on temperature measurements, in the literature, the classical parameter estimation approach uses the overall heat transfer coefficient. To reduce uncertainty in the evaluation of internal and external heat transfer coefficients, in the improved procedure, the measured temperature data were directly used without any intermediate elaboration.

The validation of the new procedure, carried out by means of synthetic data, highlighted that both the relative error on each estimated parameter and the amplitude of the confidence intervals were reduced by minimizing the objective function expressed in terms of outlet temperature of the tube side of the heat exchanger.

With regard to the transition regime, the numerical outcomes revealed that both in the laminar and turbulent regimes, the amplitude of the confidence intervals of the estimated parameters was very small; in the transition regime, the amplitude became wide. Therefore, this parameter served as a useful indicator to identify the presence of transition in the flow regime. This finding enabled a new indirect methodology, called the transition alert procedure, to be developed for identifying the Reynolds number value at which transition of the flow regime occurred. This method is an iterative subsampling of the dataset based on the observation of the amplitude of the confidence intervals.

To assess the robustness of the methodologies proposed here, the improved parameter estimation procedure and the transition alert procedure were applied to the obtained experimental data by analyzing a counter-flow heat exchanger with double corrugated tubes. In this kind of tube, the condition when the transition from the laminar to the turbulent flow regime occurs is not known a priori.
Original languageEnglish
Article number118886
JournalInternational Journal of Heat and Mass Transfer
Volume147
Number of pages15
ISSN0017-9310
DOIs
Publication statusPublished - 2019

Keywords

  • Parameter estimation
  • Transitional regime
  • Corrugated tubes
  • Heat transfer enchancement techniques
  • Nusselt number correlation

Cite this

Vocale, Pamela ; Bozzoli, Fabio ; Mocerino, Andrea ; Navickaitė, Kristina ; Rainieri, Sara. / Application of an improved parameter estimation approach to characterize enhanced heat exchangers. In: International Journal of Heat and Mass Transfer. 2019 ; Vol. 147.
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keywords = "Parameter estimation, Transitional regime, Corrugated tubes, Heat transfer enchancement techniques, Nusselt number correlation",
author = "Pamela Vocale and Fabio Bozzoli and Andrea Mocerino and Kristina Navickaitė and Sara Rainieri",
year = "2019",
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language = "English",
volume = "147",
journal = "International Journal of Heat and Mass Transfer",
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Application of an improved parameter estimation approach to characterize enhanced heat exchangers. / Vocale, Pamela; Bozzoli, Fabio; Mocerino, Andrea; Navickaitė, Kristina; Rainieri, Sara.

In: International Journal of Heat and Mass Transfer, Vol. 147, 118886, 2019.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Application of an improved parameter estimation approach to characterize enhanced heat exchangers

AU - Vocale, Pamela

AU - Bozzoli, Fabio

AU - Mocerino, Andrea

AU - Navickaitė, Kristina

AU - Rainieri, Sara

PY - 2019

Y1 - 2019

N2 - The main goals of this paper are twofold: to provide an improved parameter estimation procedure that enables the accurate evaluation of heat transfer correlations for the Nusselt number and to present a new procedure for identifying the presence of transition in the flow regime.In the first goal, it needs to be pointed out that although this kind of approach is based on temperature measurements, in the literature, the classical parameter estimation approach uses the overall heat transfer coefficient. To reduce uncertainty in the evaluation of internal and external heat transfer coefficients, in the improved procedure, the measured temperature data were directly used without any intermediate elaboration.The validation of the new procedure, carried out by means of synthetic data, highlighted that both the relative error on each estimated parameter and the amplitude of the confidence intervals were reduced by minimizing the objective function expressed in terms of outlet temperature of the tube side of the heat exchanger.With regard to the transition regime, the numerical outcomes revealed that both in the laminar and turbulent regimes, the amplitude of the confidence intervals of the estimated parameters was very small; in the transition regime, the amplitude became wide. Therefore, this parameter served as a useful indicator to identify the presence of transition in the flow regime. This finding enabled a new indirect methodology, called the transition alert procedure, to be developed for identifying the Reynolds number value at which transition of the flow regime occurred. This method is an iterative subsampling of the dataset based on the observation of the amplitude of the confidence intervals.To assess the robustness of the methodologies proposed here, the improved parameter estimation procedure and the transition alert procedure were applied to the obtained experimental data by analyzing a counter-flow heat exchanger with double corrugated tubes. In this kind of tube, the condition when the transition from the laminar to the turbulent flow regime occurs is not known a priori.

AB - The main goals of this paper are twofold: to provide an improved parameter estimation procedure that enables the accurate evaluation of heat transfer correlations for the Nusselt number and to present a new procedure for identifying the presence of transition in the flow regime.In the first goal, it needs to be pointed out that although this kind of approach is based on temperature measurements, in the literature, the classical parameter estimation approach uses the overall heat transfer coefficient. To reduce uncertainty in the evaluation of internal and external heat transfer coefficients, in the improved procedure, the measured temperature data were directly used without any intermediate elaboration.The validation of the new procedure, carried out by means of synthetic data, highlighted that both the relative error on each estimated parameter and the amplitude of the confidence intervals were reduced by minimizing the objective function expressed in terms of outlet temperature of the tube side of the heat exchanger.With regard to the transition regime, the numerical outcomes revealed that both in the laminar and turbulent regimes, the amplitude of the confidence intervals of the estimated parameters was very small; in the transition regime, the amplitude became wide. Therefore, this parameter served as a useful indicator to identify the presence of transition in the flow regime. This finding enabled a new indirect methodology, called the transition alert procedure, to be developed for identifying the Reynolds number value at which transition of the flow regime occurred. This method is an iterative subsampling of the dataset based on the observation of the amplitude of the confidence intervals.To assess the robustness of the methodologies proposed here, the improved parameter estimation procedure and the transition alert procedure were applied to the obtained experimental data by analyzing a counter-flow heat exchanger with double corrugated tubes. In this kind of tube, the condition when the transition from the laminar to the turbulent flow regime occurs is not known a priori.

KW - Parameter estimation

KW - Transitional regime

KW - Corrugated tubes

KW - Heat transfer enchancement techniques

KW - Nusselt number correlation

U2 - 10.1016/j.ijheatmasstransfer.2019.118886

DO - 10.1016/j.ijheatmasstransfer.2019.118886

M3 - Journal article

VL - 147

JO - International Journal of Heat and Mass Transfer

JF - International Journal of Heat and Mass Transfer

SN - 0017-9310

M1 - 118886

ER -