References of "Fonseca, Nestor"
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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 detailExperimental Analysis of Radiant Ceiling Systems Coupled to its Environment
Fonseca, Néstor; Cuevas, Cristian; Lemort, Vincent ULg

(2010, July)

This paper presents the results of an experimental analysis of the radiant ceiling systems in both heating and cooling modes coupled to its environment (fenestration, walls, internal loads and ventilation ... [more ▼]

This paper presents the results of an experimental analysis of the radiant ceiling systems in both heating and cooling modes coupled to its environment (fenestration, walls, internal loads and ventilation system). The main objective of this study is to present the results of the systems performance and measurement methods used to evaluate the influence of some important parameters on the radiant ceiling capacity and comfort conditions. Two test chambers are adapted in a way to reproduce as good as possible the characteristics of the real offices located in Brussels. Forty-six tests were performed in which the main objective was to observe the influence of parameters such as the mass flow rate, supply water temperature and thermal load distribution, fenestration and ventilation system effects. Laboratory test results show that the influence of surfaces temperatures inside the room, especially the facade, is considerable. Therefore, the system must be evaluated together with its designed environment and not as separate HVAC equipment. [less ▲]

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See detailDynamic Modeling and Validation of Radiant Ceiling Systems Coupled to its Environment
Fonseca, Néstor; Cuevas, Cristian; Lemort, Vincent ULg

(2010, July)

This paper presents the results of a study performed in order to develop a dynamic model of radiant ceiling panels in heating or cooling modes coupled to its environment (fenestration, walls, internal ... [more ▼]

This paper presents the results of a study performed in order to develop a dynamic model of radiant ceiling panels in heating or cooling modes coupled to its environment (fenestration, walls, internal loads and ventilation system). The model considers the radiant panels as a dynamic-state finned heat exchanger connected to a detailed lumped dynamic model of the building (R-C network). The behavior of the radiant ceiling system and the interactions with its environment has been experimentally and numerically evaluated. Using as inputs the radiant ceiling and room dimensions, material properties and the transient measurements of air temperature at the adjacent zones, supply air and water temperatures and mass flow rates, the model allows for the estimation of the water exhaust temperature, radiant ceiling average surface temperature, resultant and dry air room temperatures, radiant ceiling power and internal surface temperatures of the room in order to compare with measurements taken during the commissioning process. Two dynamic tests in heating and cooling modes are used to validate the model. [less ▲]

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See detailRadiant ceiling systems coupled to its environment part 2: Dynamic modeling and validation
Fonseca, Nestor; Bertagnolio, Stéphane ULg; Cuevas, Cristian

in Applied Thermal Engineering (2010), 30

This paper presents the results of a study performed in order to develop a dynamic model of radiant ceiling panels in heating or cooling modes coupled to its environment (fenestration, walls, internal ... [more ▼]

This paper presents the results of a study performed in order to develop a dynamic model of radiant ceiling panels in heating or cooling modes coupled to its environment (fenestration, walls, internal loads and ventilation system). The model considers the radiant panels as a dynamic-state finned heat exchanger connected to a detailed lumped dynamic model of the building (ReC network). The behavior of the radiant ceiling system and the interactions with its environment has been experimentally and numerically evaluated. Using as inputs the radiant ceiling and room dimensions, material properties and the transient measurements of air temperature at the adjacent zones, supply air and water temperatures and mass flow rates, the model allows for the estimation of the water exhaust temperature, radiant ceiling average surface temperature, resultant and dry air room temperatures, radiant ceiling power and internal surface temperatures of the room in order to compare with measurements taken during the commissioning process. Two dynamic tests in heating and cooling modes are used to validate the model. [less ▲]

Detailed reference viewed: 61 (14 ULg)
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See detailRadiant ceiling systems coupled to its environment part 1: Experimental analysis
Fonseca, Néstor; Cuevas, Cristian; Lemort, Vincent ULg

in Applied Thermal Engineering (2010), 30

This paper presents the results of an experimental analysis of the radiant ceiling systems in both heating and cooling modes coupled to its environment (fenestration, walls, internal loads and ventilation ... [more ▼]

This paper presents the results of an experimental analysis of the radiant ceiling systems in both heating and cooling modes coupled to its environment (fenestration, walls, internal loads and ventilation system). The main objective of this study is to present the results of the experimental analysis and measurement methods and its discussion. Two test chambers are adapted in a way to reproduce as good as possible the characteristics of the real offices located in Brussels (Belgium). Forty-six tests are performed to observe the influence of parameters such as the mass flow rate, supply water temperature, fenestration and ventilation system effects and thermal load distribution. Laboratory test results show that the influence of surfaces temperatures inside the room, especially the facade, is considerable. Therefore, the system must be evaluated together with its designed environment and not as separate HVAC equipment. [less ▲]

Detailed reference viewed: 34 (2 ULg)