Optimal design method for absorption heat pump cycles based on energy-utilization diagram

K. Seki, H. Hattori, Yoshiharu Amano

    Research output: Contribution to journalArticle

    Abstract

    Optimization for energy systems is considered at three levels: synthesis (configuration), design (component characteristics), and operation. The objective of this paper is to propose a method to perform design/operation optimization efficiently based on an energy-utilization diagram (EUD) for performance improvement. Before optimization, this paper evaluates the system performance and margins for improvement of two absorption heat pumps, including an absorber heat exchanger (AHX) and a solution heat exchanger (SHX). Then, exergy efficiency is higher in the SHX cycle, while the margin for improvement is larger in the AHX cycle. The optimization attempts to reduce exergy destruction in the components where dominant exergy destruction caused by heat transfer occurs. The operating points are adjusted to make the temperature gradients at hot and cold sides coincide. The design parameters in other components are adjusted to improve the heat transfer performances. The distribution of exergy destruction of each component leads to improve exergy efficiency. After these improvements, exergy efficiency is higher in the AHX cycle. It is concluded that we could efficiently realize the design/operation optimization of thermodynamic systems using an EUD, which presents both exergy destruction and margin for improvement at the components comprehensively, as well as operating properties of working fluids.

    Original languageEnglish
    Pages (from-to)9-17
    Number of pages9
    JournalInternational Journal of Thermodynamics
    Volume22
    Issue number1
    DOIs
    Publication statusPublished - 2019 Jan 1

    Fingerprint

    exergy
    heat pumps
    Exergy
    Energy utilization
    diagrams
    heat exchangers
    Pumps
    Heat exchangers
    cycles
    destruction
    optimization
    margins
    absorbers
    energy
    heat transfer
    Heat transfer
    working fluids
    Optimal design
    Hot Temperature
    Thermal gradients

    Keywords

    • Absorption heat pump system
    • Energy-utilization diagram
    • Exergy analysis
    • Optimal design

    ASJC Scopus subject areas

    • Condensed Matter Physics
    • Engineering(all)

    Cite this

    Optimal design method for absorption heat pump cycles based on energy-utilization diagram. / Seki, K.; Hattori, H.; Amano, Yoshiharu.

    In: International Journal of Thermodynamics, Vol. 22, No. 1, 01.01.2019, p. 9-17.

    Research output: Contribution to journalArticle

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