Article | Proceedings of the 9th International MODELICA Conference; September 3-5; 2012; Munich; Germany | Modeling the discontinuous individual channel injection into fin-and-tube evaporators for residential air-conditioning

Title:
Modeling the discontinuous individual channel injection into fin-and-tube evaporators for residential air-conditioning
Author:
Martin Ryhl Kærn: Technical University of Denmark, Department of Mechanical Engineering, Ljungby, Denmark Brian Elmegaard: Technical University of Denmark, Department of Mechanical Engineering, Ljungby, Denmark
DOI:
10.3384/ecp12076713
Download:
Full text (pdf)
Year:
2012
Conference:
Proceedings of the 9th International MODELICA Conference; September 3-5; 2012; Munich; Germany
Issue:
076
Article no.:
073
Pages:
713-726
No. of pages:
14
Publication type:
Abstract and Fulltext
Published:
2012-11-19
ISBN:
978-91-7519-826-2
Series:
Linköping Electronic Conference Proceedings
ISSN (print):
1650-3686
ISSN (online):
1650-3740
Publisher:
Linköping University Electronic Press; Linköpings universitet


In this paper a working principle based upon the novel expansion and distributor device EcoFlow(TM) is analyzed. The device enables compensation of flow maldistribution by control of individual channel superheat. The working principle is discontinuous liquid injection (pulsating flow) into each individual channels during a specified cycle time. Moreover; the influence of the injection cycle time is investigated together with an optional secondary flow into the other channels with regards to cooling capacity; overall UA-value and COP.

The results showed spurious fluctuations in pressure when simulating the pulsating flow; thus the dynamic behavior in the mixture two-phase flow model is insufficient to model the discontinuous liquid injection principle. Despite; the fluctuations and imperfections of the model we found that the cycle time should be kept as low as possible and that the optional secondary flow increases performance. Moreover; the paper reports on the applicability of Modelica developed models to analyze and optimize the working principle and design of expansion devices such that Modelica may be used in future development of novel discontinuous expansion devices.

Keywords: refrigeration; air-conditioning; evaporator; two-phase flow; liquid injection; pulsation; transient; dynamic; modeling; simulation; Modelica

Proceedings of the 9th International MODELICA Conference; September 3-5; 2012; Munich; Germany

Author:
Martin Ryhl Kærn, Brian Elmegaard
Title:
Modeling the discontinuous individual channel injection into fin-and-tube evaporators for residential air-conditioning
DOI:
10.3384/ecp12076713
References:
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Proceedings of the 9th International MODELICA Conference; September 3-5; 2012; Munich; Germany

Author:
Martin Ryhl Kærn, Brian Elmegaard
Title:
Modeling the discontinuous individual channel injection into fin-and-tube evaporators for residential air-conditioning
DOI:
10.3384/ecp12076713
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