Effects of an internal heat exchanger in a refrigerant system with carbon dioxide on its cooling coefficient of performance and cooling capacity

Shogo Tamaki, Yuuko Fujii, Yohsuke Matsushita, Hideyuki Aoki, Takatoshi Miura, Koichiro Take, Hidemitsu Hamano

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

The effects of an internal heat exchanger in a refrigerant system with carbon dioxide on its cooling capacity and cooling coefficient of performance were numerically investigated. First, experiments were carried out for a refrigerant system with carbon dioxide to obtain volumetric and isoentropic efficiency and to verify numerical accuracy. Second, the effects of varying internal heat exchanger area, environmental temperature, lower side pressure and higher side pressure on cooling capacity and cooling coefficient of performance were numerically investigated. By comparing calculated results with experimental ones, our simulation predicts capacity in the evaporator with +5.1% error, cooling coefficient of performance with +5.2% error, and capacity in the gas cooler with +3.0% error. When the environmental temperature is high and superheat is equal to 0 due to low performance of the evaporator, an internal heat exchanger gives a larger cooling capacity and cooling coefficient of performance. In particular, when the gas cooler exit temperature is close to the critical temperature, the internal heat exchanger gives higher performance.

Original languageEnglish
Pages (from-to)505-512
Number of pages8
Journalkagaku kogaku ronbunshu
Volume34
Issue number5
DOIs
Publication statusPublished - 2008 Oct 6

Keywords

  • Carbon dioxide
  • Coefficient of performance
  • Heat transfer rate
  • Internal heat exchanger
  • Refrigeration cycle

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)

Fingerprint Dive into the research topics of 'Effects of an internal heat exchanger in a refrigerant system with carbon dioxide on its cooling coefficient of performance and cooling capacity'. Together they form a unique fingerprint.

Cite this