References of "International Journal of Refrigeration"
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See detailExperimental Testing of an Oil-Flooded Hermetic Scroll Compressor
Bell, Ian ULg; Groll, Eckhard; Braun, James et al

in International Journal of Refrigeration (2013), 36

In this work, a residential air conditioning compressor designed for vapor injection has been modified in order to inject large quantities of oil into the working chamber in order to approach an ... [more ▼]

In this work, a residential air conditioning compressor designed for vapor injection has been modified in order to inject large quantities of oil into the working chamber in order to approach an isothermal compression process. The compressor was tested with oil injection mass flow fractions of up to 45%. At an evaporating temperature of -10C and condensing temperature of 30C, the overall isentropic efficiency was up to 70% at the highest oil injection rate. Overall, over the testing envelope investigated, there are no significantly negative effects experienced for the compressor and the compressor isentropic efficiency and refrigerant mass flow rate improve monotonically as the oil injection rate is increased. [less ▲]

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See detailA computationally efficient hybrid leakage model for positive displacement compressors and expanders
Bell, Ian ULg; Groll, Eckhard; Braun, James E. et al

in International Journal of Refrigeration (2013), 36

An empirical frictional correction factor to the isentropic nozzle model has been developed for application to refrigerant leakage modeling in scroll, rotary and other similar compressors. This correction ... [more ▼]

An empirical frictional correction factor to the isentropic nozzle model has been developed for application to refrigerant leakage modeling in scroll, rotary and other similar compressors. This correction factor is derived by calculating the leakage mass flow rate with a compressible, variable area, real gas properties model and referencing the results to an isentropic nozzle model. The ratio of flows is correlated to the Reynolds number, a characteristic length and the leakage gap width. A representative selection of fluids and geometries are employed. For all the correlations, at least 93% of the points are predicted within an absolute error band of 20%. [less ▲]

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See detailOptimization of a scroll compressor for liquid flooding
Bell, Ian ULg; Groll, Eckhard; Braun, James et al

in International Journal of Refrigeration (2012), 35(7), 19011913

In two companion papers, simulation models for the working processes of liquid-flooded scroll compressors and expanders have been developed and validated against experimental data. In this study, analytic ... [more ▼]

In two companion papers, simulation models for the working processes of liquid-flooded scroll compressors and expanders have been developed and validated against experimental data. In this study, analytic models are presented for the modes of irreversibility generation in the liquid-flooded scroll compressor including built-in volume ratio maladjustment, pressure drop and leakage. A thermodynamic model is used to derive the ideal volume ratio for a liquid-flooded compressor, which is higher than that of dry compression. An optimum set of built-in volume ratio and scroll base circle radius is found which maximizes the overall isentropic efficiency by minimizing the leakage and pressure drop irreversibilities. The irreversibility generation models are used to optimize a scroll compressor for the Liquid-Flooded Ericsson cycle application. The model predicts scroll compressor overall isentropic efficiency of over 80% (based on the shaft power) at an oil mass fraction of 88%. [less ▲]

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See detailAutomotive electric scroll compressor: Testing and modeling
Cuevas, Cristian; Fonseca, Nestor; Lemort, Vincent ULg

in International Journal of Refrigeration (2012)

The aim of this research is to characterize experimentally and by modelling an electrically driven automotive scroll compressor. The experimental characterization is carried out through 13 tests at ... [more ▼]

The aim of this research is to characterize experimentally and by modelling an electrically driven automotive scroll compressor. The experimental characterization is carried out through 13 tests at compressor speeds varying between 3000 and 5000 rpm. The DC/AC converter used to supply the compressor was characterized through a calorimetric balance, obtaining an efficiency that depends only on the compressor speed, ranging from 92.5 %, for a compressor speed of 1500 rpm, to 97.5%, for a compressor speed of 5000 rpm. The experimental results are used to identify the parameters of a semi-empirical compressor model, which is able to predict with an acceptable accuracy the main outputs of the mathematical model: confidence limits on the exhaust temperature of ± 1.0 K, on the refrigerant flow rate of ± 2 g s-1 and on the compressor power of ±60 W. This model is then used to determine the compressor cooling power at different compressor speeds and condensing pressures. [less ▲]

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See detailLiquid-flooded compression and expansion in scroll machines - Part I: Model development
Bell, Ian ULg; Lemort, Vincent ULg; Groll, Eckhard et al

in International Journal of Refrigeration (2012)

A detailed mechanistic model has been developed for scroll compressors and scroll expanders with liquid flooding for application to the Liquid Flooded Ericsson Cycle. This model is based on the ... [more ▼]

A detailed mechanistic model has been developed for scroll compressors and scroll expanders with liquid flooding for application to the Liquid Flooded Ericsson Cycle. This model is based on the integration of a set of differential equations that arise from the conservation laws. The impact of the flooding liquid on the working process is also included through mixture properties as well as treatment of two-phase flow pressure drop. With the working process known, it is then possible to solve for the compressor power, total mass flow rate and other model outputs. The fine level of detail in the model allows for the investigation of the impact of design changes to the scroll machines. This model can also be readily extended to allow for the analysis of liquid flooded vapor compression refrigeration. [less ▲]

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See detailLiquid flooded compression and expansion in scroll machines - Part II: Experimental testing and model validation
Bell, Ian ULg; Lemort, Vincent ULg; Groll, Eckhard et al

in International Journal of Refrigeration (2012), 35

The use of liquid-flooding in the compression and expansion of non-condensable gas in scroll compressors and expanders enables the possibility of quasi-isothermal working processes. Liquid-flooded scroll ... [more ▼]

The use of liquid-flooding in the compression and expansion of non-condensable gas in scroll compressors and expanders enables the possibility of quasi-isothermal working processes. Liquid-flooded scroll machines were installed in a fully-instrumented Liquid- Flooded Ericsson Cycle test rig to conduct entire cycle performance tests. In addition, detailed compressor and expander performance data was obtained. Oil mass fractions of up to 92% and 76% were added to the gas entering the scroll compressor and expander respectively. The overall isentropic efficiency of the scroll compressor based on the shaft power with flooding was up to 73% and the volumetric efficiency was above 92%. For the expander, the best overall isentropic and volumetric efficiencies achieved were 66% and 105% respectively. The mechanistic model presented in the companion paper was vali- dated against the experimental data for both the compressor and the scroll expander with good agreement, though the agreement is better for the scroll compressor. [less ▲]

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See detailPerformance of vapor compression systems with compressor oil flooding and regeneration
Bell, Ian ULg; Groll, Eckhard; Braun, James

in International Journal of Refrigeration (2011), 34(1), 225233

Vapor compression refrigeration technology has seen great improvement over the last several decades in terms of cycle efficiency through a concerted effort of manufacturers, regulators, and research ... [more ▼]

Vapor compression refrigeration technology has seen great improvement over the last several decades in terms of cycle efficiency through a concerted effort of manufacturers, regulators, and research engineers. As the standard vapor compression systems approach practical limits, cycle modifications should be investigated to increase system efficiency and capacity. One possible means of increasing cycle efficiency is to flood the compressor with a large quantity of oil to achieve a quasi-isothermal compression process, in addition to using a regenerator to increase refrigerant subcooling. In theory, compressor flooding and regeneration can provide a significant increase in system efficiency over the standard vapor compression system. The effectiveness of compressor flooding and regeneration increases as the temperature lift of the system increases. Therefore, this technology is particularly well suited towards lower evaporating temperatures and high ambient temperatures as seen in supermarket refrigeration applications. While predicted increases in cycle efficiency are over 40% for supermarket refrigeration applications, this technology is still very beneficial for typical air-conditioning applications, for which improvements in cycle efficiency greater than 5% are predicted. It has to be noted though that the beneficial effects of compressor flooding can only be realized if a regenerator is used to exchange heat between the refrigerant vapor exiting the evaporator and the liquid exiting the condenser. [less ▲]

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See detailExperimental study and modelling of cooling ceiling systems using steady-state analysis.
Fonseca, N.; Lebrun, J.; Andre, Philippe ULg

in International Journal of Refrigeration (2010), 33

Detailed reference viewed: 50 (15 ULg)