Imperial College London

ProfessorChristosMarkides

Faculty of EngineeringDepartment of Chemical Engineering

Professor of Clean Energy Technologies
 
 
 
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Contact

 

+44 (0)20 7594 1601c.markides Website

 
 
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Location

 

404ACE ExtensionSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@inproceedings{Taleb:2017:1/012016,
author = {Taleb, AI and Sapin, PMC and Barfuß, C and Fabris, D and Markides, CN},
doi = {1/012016},
publisher = {IOP Publishing: Conference Series},
title = {CFD Analysis of Thermally Induced Thermodynamic Loses in the Reciprocating Compression and Expansion of Real Gases},
url = {http://dx.doi.org/10.1088/1742-6596/821/1/012016},
year = {2017}
}

RIS format (EndNote, RefMan)

TY  - CPAPER
AB - The efficiency of expanders is of prime importance in determining the overallperformance of a variety of thermodynamic power systems, with reciprocating-piston expandersfavoured at intermediate-scales of application (typically 10–100 kW). Once the mechanical lossesin reciprocating machines are minimized (e.g. through careful valve design and operation), lossesdue to the unsteady thermal-energy exchange between the working fluid and the solid walls ofthe containing device can become the dominant loss mechanism. In this work, gas-spring devicesare investigated numerically in order to focus explicitly on the thermodynamic losses that arisedue to this unsteady heat transfer. The specific aim of the study is to investigate the behaviourof real gases in gas springs and to compare this to that of ideal gases in order to attain a betterunderstanding of the impact of real-gas effects on the thermally induced losses in reciprocatingexpanders and compressors. A CFD-model of a gas spring is developed in OpenFOAM. Threedifferent fluid models are compared: (1) an ideal-gas model with constant thermodynamicand transport properties; (2) an ideal-gas model with temperature-dependent properties; and(3) a real-gas model using the Peng-Robinson equation-of-state with temperature and pressure-dependent properties. Results indicate that, for simple, mono- and diatomic gases, like helium ornitrogen, there is a negligible difference in the pressure and temperature oscillations over a cyclebetween the ideal and real-gas models. However, when considering heavier (organic) molecules,such as propane, the ideal-gas model tends to overestimate the pressure compared to the real-gasmodel, especially if the temperature and pressure dependency of the thermodynamic propertiesis not taken into account. In fact, the ideal-gas model predicts higher pressures by as much as25% (compared to the real-gas model). Additionally, both ideal-gas models underestimate thethermall
AU - Taleb,AI
AU - Sapin,PMC
AU - Barfuß,C
AU - Fabris,D
AU - Markides,CN
DO - 1/012016
PB - IOP Publishing: Conference Series
PY - 2017///
SN - 1742-6588
TI - CFD Analysis of Thermally Induced Thermodynamic Loses in the Reciprocating Compression and Expansion of Real Gases
UR - http://dx.doi.org/10.1088/1742-6596/821/1/012016
UR - http://hdl.handle.net/10044/1/44636
ER -