References of "Lemort, Vincent"
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See detailExperimental performance characterization of a new single room ventilation device with heat recovery
Gendebien, Samuel ULg; Georges, Emeline ULg; Prieels, Luc et al

in Proceedings of the 34th AIVC conference (2013, September)

Nowadays, important efforts are made to reduce the residential building energy consumption. In this context, a growing interest for heat recovery ventilation has been observed during the last decades. The ... [more ▼]

Nowadays, important efforts are made to reduce the residential building energy consumption. In this context, a growing interest for heat recovery ventilation has been observed during the last decades. The present paper focuses on a new single room ventilation with heat recovery. Double flow ventilation is achieved through the integration of the unit into windows ledges. The developed device is particularly suitable compared to traditional centralized heat recovery ventilation units for retrofitted houses due to the absence of air extracting and air pulsing ducts through the house. The first part of the paper consists in describing the characteristics and properties of the developed device (volume, components, flow configuration, advantages and drawbacks). In the second part of the paper, an experimental approach is presented to characterize the unit. The criteria of performance are based on: - Thermal effectiveness of the unit (testing of a recovery heat exchanger), - Hydraulic aspects (flows delivered by the unit vs energy supplied to the unit), - Acoustic aspects. The overall performance of the unit can be established based on the experimental results described here above. Cartography of performance (ratio between the recovered heat and the supply electrical power) can be drawn, depending on the flow rates delivered by the unit and the indoor/outdoor temperature difference. The last part of the paper compares the new system with natural, simple exhaust ventilation and traditional centralized systems in terms of primary energy, consumer price and carbon dioxide emissions. Results show that the presented device seems more competitive than natural and simple exhaust ventilation for the Belgian climate. The single room ventilation investigated in this paper also shows better performance than most of the centralized ventilation systems tested on site. [less ▲]

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See detailInvestigation on a ventilation heat recovery exchanger: Modeling and experimental validation in dry and partially wet conditions
Gendebien, Samuel ULg; Bertagnolio, Stéphane ULg; Lemort, Vincent ULg

in Energy & Buildings (2013), 62

The present paper focuses on the development and experimental validation of a model of air-to-air heat exchanger dedicated to domestic mechanical heat recovery ventilation. The proposed model describes ... [more ▼]

The present paper focuses on the development and experimental validation of a model of air-to-air heat exchanger dedicated to domestic mechanical heat recovery ventilation. The proposed model describes dry and partially wet regimes. The first part of the paper presents a semi-empirical model based on the physical characteristics of the heat recovery device and relying on empirical correlations available in the literature for the convective heat transfer coefficients. In the case of partially wet regime, a moving boundary model is applied in order to predict sensible and latent heat transfer rates. A model developed with friction factor coefficients estimated by correlations from the literature is also presented in order to predict the hydraulic performance in dry conditions. The second part of the paper describes the experimental investigation conducted on an off-the-shelf heat exchanger. Experimental data are used to tune correlations for the determination of the convective heat transfer coefficient and validate the proposed simulation model of the ventilation heat recovery exchanger in partially wet conditions. The model developed to determine the hydraulic performance with existing correlations for the friction factor coefficient does not require a calibration. Finally, examples of use of the developed model are presented, which includes coupling the model with a building simulation model, a study of the influence of the humidity on the evolution of the latent and sensible heat transfer rates and strategies to avoid freezing in the heat exchanger. [less ▲]

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See detailExperimental study on an open-drive scroll expander integrated into an ORC (Organic Rankine Cycle) system with R245fa as working fluid
Declaye, Sébastien ULg; Quoilin, Sylvain ULg; Guillaume, Ludovic ULg et al

in Energy (2013), 15

The present paper focuses on the experimental characterization of an open-drive scroll expander integrated into an Organic Rankine cycle using R245fa as working fluid. The expander is a commercially ... [more ▼]

The present paper focuses on the experimental characterization of an open-drive scroll expander integrated into an Organic Rankine cycle using R245fa as working fluid. The expander is a commercially available air compressor that was modified to operate in expander mode. The ORC (Organic Rankine Cycle) system is designed for a nominal heat input of 20 kW and a nominal net power output of 1.8 kW. A total of 74 steady-state operating points are measured to evaluate the expander performance over a wide range of conditions. The operating parameters that are varied include the inlet pressure (from 9 to 12 bar), outlet pressure (from 1.5 to 4 bar) and rotational speed (from 2000 to 3500 rpm). The maximum isentropic efficiency and shaft power are, respectively, 75.7% and 2.1 kW. A maximum cycle efficiency of 8.5% is reached for evaporating and condensing temperatures of 97.5 °C and 26.6 °C respectively. For most of the tests, hot water is produced in the condenser and the system therefore behaves as a CHP (combined heat and power). Depending on the water temperature requirement, a power to heat ratio varying between 1.9% and 11.8% is obtained. Water over 50 °C can be produced with a power to heat ratio higher than 8%. The experimental data points are then used to generate a performance map of the expander. This performance map allows for simulation of the use of such an expander in other ORC system [less ▲]

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See detailModeling and simulation of the domestic energy use in Belgium following a bottom-up approach
Georges, Emeline ULg; Gendebien, Samuel ULg; Bertagnolio, Stéphane ULg et al

in Proceedings of the CLIMA 2013 11th REHVA World Congress & 8th International Conference on IAQVEC (2013, June)

The present paper presents a “bottom-up” approach dedicated to the modeling and simulation of the domestic energy use. This methodology focuses first on a microanalysis (i.e. modeling and simulation of a ... [more ▼]

The present paper presents a “bottom-up” approach dedicated to the modeling and simulation of the domestic energy use. This methodology focuses first on a microanalysis (i.e. modeling and simulation of a set of representative households). Results from this micro-analysis are then used and extended to allow drawing conclusions at a macro-scale. The methodology can be validated by comparing simulation results to annual national energy consumption indexes or synthetic load profiles (energy consumption profiles generated from values of predefined past periods). Once the method is validated, it can be used to study the impact of different retrofit scenarios on the annual energy use and on the energy demand profiles. This paper describes the methodology developed for Belgium. [less ▲]

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See detailTechno-economic survey of Organic Rankine Cycle (ORC) systems
Quoilin, Sylvain ULg; van den Broeck, Martijn; Declaye, Sébastien ULg et al

in Renewable & Sustainable Energy Reviews (2013), 22

New heat conversion technologies need to be developed and improved to take advantage of the necessary increase in the supply of renewable energy. The Organic Rankine Cycle is well suited for these ... [more ▼]

New heat conversion technologies need to be developed and improved to take advantage of the necessary increase in the supply of renewable energy. The Organic Rankine Cycle is well suited for these applications, mainly because of its ability to recover low-grade heat and the possibility to be implemented in decentralized lower-capacity power plants. In This paper, an overview of the different ORC applications is presented. A market review is proposed including cost figures for several commercial ORC modules and manufacturers. An in-depth analysis of the technical challenges related to the technology, such as working fluid selection and expansion machine issues is then reported. Technological constraints and optimization methods are extensively described and discussed. Finally, the current trends in research and development for the next generation of Organic Rankine Cycles are presented. [less ▲]

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See detailDesign of a small-scale organic Rankine cycle engine used in a solar power plant
Georges, Emeline ULg; Declaye, Sébastien ULg; Dumont, Olivier ULg et al

in International Journal of Low Carbon Technologies (2013)

Under the economic and political pressure due to the depletion of fossil fuels and global warming concerns, it is necessary to develop more sustainable techniques to provide electrical power. In this ... [more ▼]

Under the economic and political pressure due to the depletion of fossil fuels and global warming concerns, it is necessary to develop more sustainable techniques to provide electrical power. In this context, the present study aims at designing, building and testing a small-scale organic Rankine cycle (ORC) solar power plant ( 3 kWe) in order to define and optimize control strategies that could be applied to larger systems. This paper presents a first step of the design of the solar power plant and focuses more specifically on the ORC engine. This design is defined on the basis of simulation models of the ORC engine and takes into account some technical limitations such as the allowed operating ranges and the technical maturity of the components. The final configuration includes a diaphragm pump, two plate heat exchangers for the regenerator and the evaporator, an air-cooled condenser, two hermetic scroll expanders in series and R245fa as the working fluid. Simulations indicate that an efficiency close to 12% for the ORC engine can be reached for evaporating and condensing temperatures of 140 and 358C, respectively. [less ▲]

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See detailEtude tribologique sur des lubrifants solides à haute température
Legros, Arnaud ULg; Zaïdi, Hamid; Diny, Mouad et al

Poster (2013, May)

Actuellement, environ 2/3 de l’énergie libérée par la combustion de l’essence est rejetée sous forme de chaleur, soit dans les gaz d’échappement, soit dans le liquide de refroidissement. Un cycle de ... [more ▼]

Actuellement, environ 2/3 de l’énergie libérée par la combustion de l’essence est rejetée sous forme de chaleur, soit dans les gaz d’échappement, soit dans le liquide de refroidissement. Un cycle de Rankine peut être utilisé afin de valoriser la chaleur des gaz d’échappement. Cependant, aucune machine de détente commerciale n’est adaptée aux conditions de récupération d’énergie sur gaz d’échappement. La tribologie, plus particulièrement celle des lubrifiants solides à haute température, peut intervenir afin d’étudier les couples de matériaux adéquats pour réaliser les joints de la machine de détente du cycle. Cela permet de réduire les pertes globales de la machine et d’en améliorer le rendement. [less ▲]

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See detailA comparison of piston, screw and scroll expanders for small scale Rankine cycle systems
Lemort, Vincent ULg; Guillaume, Ludovic ULg; Legros, Arnaud ULg et al

in Proceedings of the 3rd International Conference on Microgeneration and Related Technologies (2013, April)

This paper aims at helping the designer of micro-scale Rankine Cycle heat engines to best select the expander among piston, screw and scroll machines. The first part of the paper presents a state of the ... [more ▼]

This paper aims at helping the designer of micro-scale Rankine Cycle heat engines to best select the expander among piston, screw and scroll machines. The first part of the paper presents a state of the art of these three technologies of positive displacement machines. The technical constraints inherent to each machine (rotational speed, pressure ratios, maximum temperatures, volumetric expansion ratios, etc.) are listed and the performance mentioned in the open technical and scientific literature is presented. The second part of the paper deals with the modeling of such expanders. Different simulation models are proposed: black-box, grey-box and white-box models. These three categories of modeling are specifically adapted to different purposes: design of the expander, design of the micro-CHP system, and dynamic simulation/control of the CHP unit. The last part of the paper presents a graphical methodology of selection of expansion machines and working fluids based on operating maps. It is stressed that the selections of both the expansion machine and working fluid should be conducted simultaneously. [less ▲]

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See detailTheorical study of a volumetric hot air Joule cycle engine
Oudkerk, Jean-François ULg; Lemort, Vincent ULg

in Proceedings of the 3rd International Conference on Microgeneration and Related Technologies (2013, April)

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See detailMonitoring of real GEO-HP-TABS (Geothermal Heat Pumps connected to Thermally Activated Building Systems)
Lemort, Vincent ULg

Report (2013)

This report presents the analysis of measurement data collected on five different buildings in the frame of WP4 (“Monitoring of real GEO-HP-TABS”) of GEOTABS project. These office buildings are located in ... [more ▼]

This report presents the analysis of measurement data collected on five different buildings in the frame of WP4 (“Monitoring of real GEO-HP-TABS”) of GEOTABS project. These office buildings are located in Germany (buildings A and B) and in Belgium (buildings C, D and E). First of all, the buildings architecture will be presented. The control strategies of the HVAC systems used in these buildings will also be described. Then the energy performance of each building system will be assessed and discussed (on seasonal, daily and monthly bases). The evaluation of the energy performance will be based on monitoring data collected on the geothermal heat pump – TABS systems and other HVAC components. An analysis of the long-term thermal comfort will be presented. Finally, an economic and environmental analysis will be performed for two of the buildings. [less ▲]

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See detailEtude tribologique sur des lubrifiants solides à haute température dans des machines de détente
Legros, Arnaud ULg; Zaïdi, Hamid; Diny, Mouad et al

in La tribologie : fondamentaux et applications complexes (2013)

Dans le cadre de la conception d’un expanseur dédié à la récupération d’énergie à l’échappement d’un moteur à combustion interne, une étude sur des lubrifiants solides a été menée afin de choisir le ... [more ▼]

Dans le cadre de la conception d’un expanseur dédié à la récupération d’énergie à l’échappement d’un moteur à combustion interne, une étude sur des lubrifiants solides a été menée afin de choisir le couple de matériaux adéquat pour le joint principal de la machine. Ce joint doit assurer à la fois une fonction d’étanchéité interne et limiter ainsi les pertes par fuites internes de l’expanseur. Il doit également présenter un coefficient de frottement la plus faible possible afin de réduire les pertes par friction. Ce joint est en effet sollicité par des contraintes en frottement plan dans un environnement sous vapeur d’eau à des températures pouvant atteindre 250°C. Ces températures rendent complexe l’utilisation d’huile et le recours à des matériaux auto lubrifiants est dès lors l’unique solution. [less ▲]

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See detailOrganic Rankine Cycle Systems: A Techno-Economic Overview
van den Broeck, Martijn; Quoilin, Sylvain ULg; Declaye, Sébastien ULg et al

in Proceedings of EMC 2013 (2013)

The potential of organic Rankine cycle (ORC) technology for waste heat recovery in industry is discussed. This survey includes a market overview, a discussion of the key differences with steam turbine ... [more ▼]

The potential of organic Rankine cycle (ORC) technology for waste heat recovery in industry is discussed. This survey includes a market overview, a discussion of the key differences with steam turbine technology, some main selection issues (components and working fluid) and an outlook on the future of the technology. [less ▲]

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See detailDevelopment of a generalized steady-state simulation framework for positive displacement compressors and expanders
Bell, Ian ULg; Lemort, Vincent ULg; Groll, Eckhard et al

in Proceedings of the International Conference on Compressors and their Systems 2013 (2013)

In this paper, a generalized framework is presented that can be used to simulate the steady-state performance of a wide range of positive displacement compressors and expanders (scroll, piston, screw ... [more ▼]

In this paper, a generalized framework is presented that can be used to simulate the steady-state performance of a wide range of positive displacement compressors and expanders (scroll, piston, screw, rotary, spool, etc.). The complete simulation algorithm is described, and an emphasis is placed on the numerical methods required to obtain robust behavior of the simulation. This formulation has been implemented into an open-source software package entitled PDSim written in the Python language. PDSim is the first open-source generalized compressor and expander simulation package. The source code can be freely obtained from http://pdsim.sf.net [less ▲]

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See detailSimulation-assisted evaluation of potential energy savings: Application to an administrative building in France
Randaxhe, François ULg; Bertagnolio, Stéphane ULg; Lemort, Vincent ULg

in Randaxhe, François; Bertagnolio, Stéphane; Lemort, Vincent (Eds.) International Conference for Enhanced Building Operations ICEBO 2012 at Manchester, October 23-26, 2012 (2012, October)

The case study presented here falls within a project of feasibility studies to improve the energy efficiency, the carbon footprint and the environmental impacts of several administrative buildings in ... [more ▼]

The case study presented here falls within a project of feasibility studies to improve the energy efficiency, the carbon footprint and the environmental impacts of several administrative buildings in France. The first part of the paper briefly presents the data obtained during a classical audit and inspection procedure: the description of the building in term of design, the HVAC system characteristics, the occupancy and operating profiles and the control strategy applied. The second part of the paper gives the first results obtained using an evidence-based calibrated building energy simulation model to analyze the actual building global consumption but also analyze the local consumptions (heat pumps, air handling units, terminal units, lightings, pumps,...). The last part of the paper then demonstrates the possibilities given by the building energy simulation model to evaluate potential energy saving scenarios through different examples. The advantages and drawbacks of the applied methods and tools are also discussed. [less ▲]

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See detailDynamic modeling and control strategies for Organic Rankine Cycle systems
Quoilin, Sylvain ULg; Lemort, Vincent ULg

Conference (2012, September 13)

Control and optimization are major issues in ORC systems applied to waste heat sources. This talk provides an overview of the current state of the art and of the main areas of R&D in that topic, including ... [more ▼]

Control and optimization are major issues in ORC systems applied to waste heat sources. This talk provides an overview of the current state of the art and of the main areas of R&D in that topic, including: - Steady-state and dynamic modeling of ORC cycles (simulation platforms, modeling paradigms, numerical issues) - Optimization of the working conditions for a given heat source and heat sink, and in particular of the evaporating temperature - Optimal start-up and shut-down strategies (grid synchronization, pressure overshoot, ...) - Control of the cycle under transient heat source conditions - Traditional and advanced controllers (PID, Model predictive control) The different adjustable working conditions (condensing/evaporating temperature, superheating, subcooling, working fluid flow rate) are listed with regard to the available degrees of freedom (pump/expander speed, secondary fluid flow rates and temperatures) and their optimal values are derived, depending on the target application. [less ▲]

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See detailAdvances in ORC expander design
Lemort, Vincent ULg; Quoilin, Sylvain ULg

Conference (2012, September 13)

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See detailCharacterisation of a scroll expander for small scale absorption power and cooling cycle activated by solar energy or waste heat
Mendoza, Luis Carlos; Navarro, Joaquin; Lemort, Vincent ULg et al

Poster (2012, September)

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See detailDESIGN OF A SMALL-SCALE ORGANIC RANKINE CYCLE ENGINE USED IN A SOLAR POWER PLANT
Declaye, Sébastien ULg; Georges, Emeline ULg; Bauduin, Maxime ULg et al

in Proceedings of Heat Powered Cycles Conference 2012 (2012, September)

Under the economical and political pressure due to the depletion of fossil fuel and global warming potential, it is necessary to develop more sustainable techniques to provide electrical power. In this ... [more ▼]

Under the economical and political pressure due to the depletion of fossil fuel and global warming potential, it is necessary to develop more sustainable techniques to provide electrical power. In this context, medium and large scale Organic Rankine Cycle solar power plants appear to be a promising solution because of their good efficiency, robustness and acceptable economical probability. However, only a few ORC solar power plants are in operation today, but technical literature indicate that several demonstration projects are under development. The spreading out of that technology requires, among others, a good knowledge of control strategies of the entire plant comprising the field of parabolic trough collectors, the ORC engine and thermal storage systems. The present project aims at designing, building and testing a small scale ORC solar power plant (a few kWe) in order to define and optimize control strategies that could be applied to larger systems. The paper presents the design step of the solar power plant, and more specifically the ORC engine. This design is defined based on simulation models of the ORC engine and on the experience gained in the Thermodynamics laboratory in the field of testing small-scale ORC systems. The design accounts for technical limitations such as allowed operating ranges and technical maturity of components. The paper first presents the architecture of the envisioned solar plant. The choice of the different technologies of components is justified. Simulation models of components (scroll expander, plate and fin-and-tubes heat exchangers, etc.) and of the whole system are then presented. Based on those models, parametric studies are conducted in order to optimize the sizing and the operating conditions of the system and to select the most appropriate working fluid. Also, the relevance of using two expanders in series is discussed and the control of the ORC engine is investigated. Simulations indicate that ORC engine efficiency close to 12% can be reached for evaporating and condensing temperatures of 140°C and 35°C. [less ▲]

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See detailExperimental investigation on a decentralized air handling terminal: procedure of aeraulic and thermal performance determination of the entire unit under several operating conditions
Gendebien, Samuel ULg; Prieels, Luc; Lemort, Vincent ULg

in Proceedings of the 6th European Thermal Sciences Conference (2012, September)

A new local ventilation device is actually developed in such a way to procure ventilation “on demand” in each room, with a maximal effectiveness. It consists in a wall or window frame mounted plane ... [more ▼]

A new local ventilation device is actually developed in such a way to procure ventilation “on demand” in each room, with a maximal effectiveness. It consists in a wall or window frame mounted plane-parallel box, containing two (injection and extraction) fans, an electronic control, and a heat recovery exchanger. The present paper describes the experimental investigations carried out on some single components and on the entire unit in order to characterize the aeraulic and thermal performance of the device. [less ▲]

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