References of "Lemort, Vincent"
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See detailExplicit Multi Model Predictive Control of a Waste Heat Rankine Based System for Heavy Duty Trucks
Grelet, Vincent; Dufour, Pascal; Nadri, Madiha et al

in Proceedings of the 54th IEEE Conference on Decision and Control (2015)

This paper presents an explicit multi-model predictive controller (MMPC) for a waste heat recovery system (WHRS) mounted on a heavy duty truck engine. WHRS based on the Rankine cycle principle attracts a ... [more ▼]

This paper presents an explicit multi-model predictive controller (MMPC) for a waste heat recovery system (WHRS) mounted on a heavy duty truck engine. WHRS based on the Rankine cycle principle attracts a lot of interest in the heavy duty industry, over the past few years, to decrease the fuel consumption and reach the future pollutant emissions standards. Control issues have still to be faced before the integration of such a system into a vehicle. Model predictive controllers suits really well for our control purpose due to their ability to handle online optimal control problem. This paper focuses on the development of an explicit control law based on MMPC with aim to control the fluid temperature at the inlet of the expansion machine in order to increase the system performance and the reliability. [less ▲]

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See detailWaste heat recovery rankine cycle based system modeling for heavy duty trucks fuel saving assessment
Grelet, Vincent; Lemort, Vincent ULg; Nadri, Madiha et al

in Proceedings of the 3rd ASME International Seminar on ORC Power Systems (ORC) (2015)

This paper presents a method to model heat exchangers used in waste heat recovery Rankine based systems in heavy duty trucks. The method is developed to predict both transfer and working fluid physical ... [more ▼]

This paper presents a method to model heat exchangers used in waste heat recovery Rankine based systems in heavy duty trucks. The method is developed to predict both transfer and working fluid physical properties such as temperature and density after the heat exchange process. Due to the flexibility of such a model, it can be used for a numerous quantity of fluids including water-alcohol mixture. A validation of the developed model is shown and compared to steady state and dynamic test results. The model shows good performance as well in terms of accuracy, which is in the range of 5K error as in computational time which is faster than real time and makes it suitable for concept optimization, control and fuel economy evaluation. [less ▲]

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See detailModel based control for waste heat recovery rankine cycle system in heavy duty trucks
Grelet, Vincent; Dufour, Pascal; Nadri, Madiha et al

in Proceedings of the 3rd ASME International Seminar on ORC Power Systems (ORC) (2015)

Driven by future emissions legislations and increase in fuel prices engine, gas heat recovering has recently attracted a lot of interest. In the past few years, a high number of studies have shown the ... [more ▼]

Driven by future emissions legislations and increase in fuel prices engine, gas heat recovering has recently attracted a lot of interest. In the past few years, a high number of studies have shown the interest of energy recovery Rankine based systems for heavy duty trucks engine compounding. Recent studies have brought a significant potential for such a system in a Heavy Duty (HD) vehicle, which can lead to a decrease in fuel consumption of about 5% [Wang et al. (2011)] and reduce engine emissions. But many challenges still need to be faced before the vehicle integration. This paper presents a control strategy development for waste heat recovery Rankine based systems in heavy duty trucks. Due to the highly transient operating conditions, improving the control strategy of those systems is an important step to their integration into a vehicle. It is shown here that moving to more advanced control strategies than classical PIDs lead to some gains in terms of performance. Due to the limited availability and high operational cost of test bench, the validation of such a controller is done on a representative and previously validated model. [less ▲]

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See detailDevelopment of a compact single room ventilation unit with heat recovery dedicated to tertiary buildings
Gendebien, Samuel ULg; Martens, Jonathan; Prieels, Luc et al

Conference (2015)

In the frame of the European project called Bricker, a new prototype of single room ventilation with heat recovery has been developed. This new unit is supposed to be installed in class rooms of an ... [more ▼]

In the frame of the European project called Bricker, a new prototype of single room ventilation with heat recovery has been developed. This new unit is supposed to be installed in class rooms of an educational institution. This paper deals with the development of the first prototype of this unit. An empirical model of such device is also proposed in order to be coupled with a building model. This aims at determining the seasonal performance of the device and thus the potential energy saving (compared to other technologies) resulting from its use. The first part of the paper presents the specifications and the final characteristics of the developed device. In this context, a by-pass for free cooling in summer conditions as well as the strategies under frosting conditions are described. Secondly, the coefficient of performance (COP) of such device is recalled. In the early stage of the development process, the COP is determined based on the manufacturer data of the heat recovery exchanger and the fans. The coupling between fan curve and the predicted hydraulic performance of the unit allows for determining a first approximation of the fans electrical consumption for several delivered flow rates. The third part of the paper focuses on the experimental investigations carried out in order to determine the flow rate really delivered by the unit. Electrical consumptions of several flow rates are also measured in order to characterize the COP of the unit in those conditions. Finally, a comparison between the measured and the predicted performance based on manufacturer data has been realized in terms of COP. A performance map based on experimental results is proposed in order to be coupled with a building model. [less ▲]

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See detailComparaison des performances de deux types de technologies pour obtenir un bâtiment à énergie positive : le système PAC/ORC réversible et une pompe à chaleur couplée avec des panneaux photovoltaïques.
Dumont, Olivier ULg; Lemort, Vincent ULg

Conference (2015)

Afin d’atteindre les objectifs 20-20-20 en 2020 ainsi que les objectifs européens à plus long terme, il est impératif de réduire drastiquement les émissions dues au secteur du bâtiment, qui compte pour ... [more ▼]

Afin d’atteindre les objectifs 20-20-20 en 2020 ainsi que les objectifs européens à plus long terme, il est impératif de réduire drastiquement les émissions dues au secteur du bâtiment, qui compte pour plus de 27% de la consommation finale d’énergie en Europe. Dans ce cadre, le développement des bâtiments à énergie positive est une voie prometteuse. Ce travail compare les performances annuelles de deux systèmes concurrents. D’une part, une solution classique, consistant en une maison passive couplée à une pompe à chaleur eau-eau et à des panneaux photovoltaïques (HP+PV). D’autre part, une maison passive avec un toit solaire thermique combinée à une unité pompe à chaleur / cycle organique de Rankine réversible (système PAC/ORC réversible). Cette unité modulable, étudiée et brevetée depuis 3 ans, permet trois modes de fonctionnement : le mode PAC pour les besoins en chaleurs en hiver, le mode ORC pour la génération d’électricité et un mode de chauffage direct, utilisant l’énergie thermique générée par le toit solaire pour les besoins en chaleur du bâtiment. Les deux systèmes sont dimensionnés pour une puissance de production électrique maximale de 6 kW. Les simulations dynamiques sont effectuées à l’aide du logiciel Dymola couplé à la librairie Modelica. Les modèles utilisés sont présentés dans la version complète de ce travail. La figure 1 compare la production électrique nette annuelle ainsi que les bénéfices de fonctionnement pour les deux systèmes étudiés et pour différents climats. Il s’avère que la solution HP+PV présente de meilleures performances tant au niveau production électrique nette qu’au niveau bénéfices de fonctionnement. Par contre, la consommation électrique de la pompe à chaleur est réduite grâce au mode chauffage direct dans le cas du système PAC/ORC réversible. [less ▲]

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See detailProceedings of the Ninth International Conference on System Simulation in Buildings - SSB 2014
Lemort, Vincent ULg; Randaxhe, François ULg

in System Simulation in Buildings (2015)

This 9th International Conference on System Simulation in Buildings has been the opportunity to gather researchers coming from 13 countries, sharing the last results of their research works. Some of the ... [more ▼]

This 9th International Conference on System Simulation in Buildings has been the opportunity to gather researchers coming from 13 countries, sharing the last results of their research works. Some of the presented works were conducted in the frame of projects from the International Energy Agency’s Energy in Buildings and Communities Programme (EBC). [less ▲]

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See detailLessons Learned from Heat Balance Analysis for Holzkirchen Twin Houses Experiment
Masy, Gabrielle; Rehab, Imane ULg; Andre, Philippe ULg et al

in Energy Procedia (2015)

Holzkirchen full scale dynamic experiments were conducted in the framework of IEA Annex 58 research program with the aim to obtain and apply a high quality experimental dataset for model validation of ... [more ▼]

Holzkirchen full scale dynamic experiments were conducted in the framework of IEA Annex 58 research program with the aim to obtain and apply a high quality experimental dataset for model validation of full scale buildings. A first experiment was conducted in August 2013. Two identical houses were submitted to a side by side experiment, one with blinds up, one with blinds down. That first experience lasted 42 days including an initialization period, a Randomly Ordered Logarithmic Binary Sequence of heat inputs (ROLBS), and a re-initialization followed by a free-float period. A second experiment was conducted in April 2014 in one of the two houses, with higher levels of heating power in the South oriented zones and imposed indoor temperatures in the North oriented zones. Simulations were performed with EES Engineering Equation Solver using simplified RC dynamic models. The discrepancies observed between simulated results and measured data were first explained through a deeper analysis of thermal bridges, a better assessment of solar heat gains and a better assessment of the air duct heat losses. In the second experiment, the results revealed an underestimation of the building transmission heat losses. A candidate explanation might be the air stratification which would enhance heat losses on the ceiling side. A modelization of the upper and lower room air layers was introduced. The resulting simulated indoor temperature profiles were in accordance with the measurements. A complete breakdown of heat losses and heat gains was computed for both houses, using measured temperatures as input data for the simulation. [less ▲]

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See detailImpact of net metering programs on optimal load management in US residential housing – a case study
Georges, Emeline ULg; Braun, J. E.; Groll, E. et al

in Proceedings of 9th International Conference on System Simulation in Buildings (2014, December 11)

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See detailSimulation of a passive house coupled with a reversible heat pump/organic Rankine cycle unit
Dumont, Olivier ULg; Carmo, Carolina; Randaxhe, François ULg et al

Conference (2014, December)

This paper presents a dynamic model of a passive house located in Denmark with a large solar absorber, a horizontal ground heat exchanger coupled with a HP/ORC unit. The HP/ORC reversible unit is a module ... [more ▼]

This paper presents a dynamic model of a passive house located in Denmark with a large solar absorber, a horizontal ground heat exchanger coupled with a HP/ORC unit. The HP/ORC reversible unit is a module able to work as an Organic Rankine Cycle (ORC) or as a heat pump (HP). There are 3 possible modes that need to be chosen optimally depending on the weather conditions, the heat demand and the temperature level of the storage. The ORC mode is activated, as long as the heat demand of the house is covered by the storage to produce electricity based upon the heat generated by the solar roof. The direct (free) heating is used when the storage cannot cover the heat demand of the house. Finally, when direct heating is not sufficient to cover the heat demand because of poor weather conditions, the HP mode is activated. Dynamic simulations of the whole system are presented for different typical days of the year in the Modelica language. A peak of 3.28 kW of power is reached in ORC mode with a heat input of 59.5 kW from the solar roof (23.9 kWh are produced during a typical summer day). In a representative winter day, 17.28 kWh are consumed by the heat pump with a daily average COP of 4.1. Conclusions regarding control strategies and enhancement of the global system are drawn. A control strategy with a low storage temperature set-point (50˚C) allows reducing electrical consumption from 11% up to 24% when compared to higher set-point (60˚C). The system performance to produce power could also be optimized if an extra tank is included to store heat uniquely to produce electricity with the ORC during the peak electricity consumption. Finally, this technology is a promising way to achieve Net Zero Energy Building at low price compared to competitive products (heat pump combined with PV for example). The system presents a higher global COP because the heat produced on the roof can heat the storage directly. [less ▲]

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See detailMethodology to characterize a residential building stock using a bottom-up approach: a case study applied to Belgium
Gendebien, Samuel ULg; Georges, Emeline ULg; Bertagnolio, Stéphane et al

in International Journal of Sustainable Energy Planning and Management (2014)

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See detailDynamic modeling and control strategy analysis of a micro-scale CSP plant coupled with a thermocline system for power generation
Dickes, Rémi ULg; Desideri, Adriano ULg; Bell, Ian ULg et al

Conference (2014, September 17)

Concentrated solar power systems are characterized by strong transients and require proper control guidelines to operate efficiently. In this context, a dynamic model of a 5 kWe solar ORC system is ... [more ▼]

Concentrated solar power systems are characterized by strong transients and require proper control guidelines to operate efficiently. In this context, a dynamic model of a 5 kWe solar ORC system is developed in the Modelica language to investigate the possible advantages of coupling a concentrating solar power system with a thermocline packed-bed storage. The models of the solar field, the thermocline storage and the ORC unit are described and integrated in the open-source ThermoCycle library. A first regulation strategy is proposed and implemented into a controller unit. Results of a three-day simulation using real meteorological data are finally analyzed and discussed. [less ▲]

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See detailCalibration of Building Simulation Models: Assessment of Current Acceptance Criteria
Ruiz Flores, Roberto ULg; Lemort, Vincent ULg

in Proceedings of the 8th International Conference Improving Energy Efficiency in Commercial Buildings (IEECB’14) (2014, September)

In this paper, the most used acceptance criteria in calibration of building simulation models are introduced and tried out by means of a practical exercise. In order to simplify the process of obtaining ... [more ▼]

In this paper, the most used acceptance criteria in calibration of building simulation models are introduced and tried out by means of a practical exercise. In order to simplify the process of obtaining “simulated data” and to avoid carrying out a formal calibration procedure; two yearly testing profiles (hourly time scale) are created from real building electrical metered data (¼ hour profile). Both testing profiles represent two model responses that could possibly be obtained in a common calibration procedure. The objective of this work is to test the capabilities of the method to determine (1) the model adequacy to represent an existing situation; (2) the reliability of the model when predicting a future or different scenario and also (3) the ability of the method to orient the practitioner to upgrade the model when it provides a non-satisfactory response. To do this, the real accuracy of both testing profiles is verified by means of a complementary statistical bin analysis. This crosschecking analysis allows highlighting the strengths and weakness of the current criteria and determining whether they need to be revised, modified or complemented. At the end of the analysis, it is concluded that the capabilities of the current acceptance criteria are limited because don’t provide any satisfactory answer, indication or clue for none of the three points aforementioned and some other complementary tests (such as bin analysis) must be implemented and performed in order to properly declare a model as calibrated. [less ▲]

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See detailIncreasing the efficiency of Organic Rankine Cycle Technology by means of Multivariable Predictive Control
Hernandez Naranjo, Jairo Andrés ULg; Desideri, Adriano ULg; Ionescu, Clara et al

Conference (2014, August 25)

The Organic Rankine Cycle (ORC) technology has become very popular, as it is extremely suitable for waste heat recovery from low-grade heat sources. As the ORC system is a strongly coupled nonlinear ... [more ▼]

The Organic Rankine Cycle (ORC) technology has become very popular, as it is extremely suitable for waste heat recovery from low-grade heat sources. As the ORC system is a strongly coupled nonlinear multiple-input multiple-output (MIMO) process, conventional control strategies (e.g. PID) may not achieve satisfactory results. In this contribution our focus is on the accurate regulation of the superheating, in order to increase the e fficiency of the cycle and to avoid the formation of liquid droplets that could damage the expander. To this end, a multivariable Model Predictive Control (MPC) strategy is proposed, its performance is compared to the one of PI controllers for the case of variable waste-heat source profi les. [less ▲]

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See detailComparison and impact of waste heat recovery technologies on passenger car fuel consumption on a normalized driving cycle
Legros, Arnaud ULg; Guillaume, Ludovic ULg; Diny, Mouad et al

in Energies (2014)

The purpose of this article was to compare different waste heat recovery system technologies designed for automotive applications. A complete literature review is done and results in two comparative ... [more ▼]

The purpose of this article was to compare different waste heat recovery system technologies designed for automotive applications. A complete literature review is done and results in two comparative graphs. In the second part, simulation models are built and calibrated in order to assess the fuel consumption reduction that can be achieved on a real driving cycle. The strength of this article is that the models are calibrated using actual data. Finally, those simulations results are analyzed and the Rankine cycle and turbocompound are the two most profitable solutions. However the simulations of the turbocompound shows its limitations because the impact on the exhaust pressure drop is not taken into account in the assessment of the car fuel consumption. Fuel reduction of up to 6% could be achieved, depending on the driving cycle and the waste heat recovery technology. [less ▲]

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See detailSmart Grid Energy Flexible Buildings through the use of Heat Pumps in the Belgian context
Georges, Emeline ULg; Masy, Gabrielle; Verhelst, Clara et al

in 3rd International High Performance Buildings Conference at Purdue (2014, July)

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See detailSystematic optimization of subcritical and transcritical organic Rankine cycles (ORCs) constrained by technical parameters in multiple applications
Maraver, Daniel; Royo, Javier; Lemort, Vincent ULg et al

in Applied Energy (2014), 117

The present work is focused on the thermodynamic optimization of organic Rankine cycles (ORCs) for power generation and CHP from different average heat source profiles (waste heat recovery, thermal oil ... [more ▼]

The present work is focused on the thermodynamic optimization of organic Rankine cycles (ORCs) for power generation and CHP from different average heat source profiles (waste heat recovery, thermal oil for cogeneration and geothermal). The general goal is to provide optimization guidelines for a wide range of operating conditions, for subcritical and transcritical, regenerative and non-regenerative cycles. A parameter assessment of the main equipment in the cycle (expander, heat exchangers and feed pump) was also carried out. An optimization model of the ORC (available as an electronic annex) is proposed to predict the best cycle performance (subcritical or transcritical), in terms of its exergy efficiency, with different working fluids. The working fluids considered are those most commonly used in commercial ORC units (R134a, R245fa, Solkatherm, n-Pentane, Octamethyltrisiloxane and Toluene). The optimal working fluid and operating conditions from a purely thermodynamic approach are limited by the technological constraints of the expander, the heat exchangers and the feed pump. Hence, a complementary assessment of both approaches is more adequate to obtain some preliminary design guidelines for ORC units. [less ▲]

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See detailDesign, modelling, performance optimization and experimentation of a reversible HP/ORC prototype.
Dumont, Olivier ULg; Quoilin, Sylvain ULg; Lemort, Vincent ULg

Conference (2014)

This paper presents an innovative system comprising a water/water heat pump connected to a solar roof and a geothermal heat exchanger. This unit is able to invert its cycle and operate as an Organic ... [more ▼]

This paper presents an innovative system comprising a water/water heat pump connected to a solar roof and a geothermal heat exchanger. This unit is able to invert its cycle and operate as an Organic Rankine Cycle. The solar roof is producing a large amount of heat throughout the year. This allows covering the building annual heating needs and furthermore, electricity is produced thanks to the surplus of heat in a so-called HP/ORC reversible unit. This paper is focusing on these three main points: modeling, design and experimentation of the prototype. This paper demonstrates the feasibility of such a prototype with encouraging performance in ORC and HP modes. First simulations of the HP/ORC system, with components optimally sized, indicate that, in ORC mode, for the weather conditions of Copenhagen, the electrical energy produced over one year reaches 4030 kWh and the nominal efficiency of the cycle is 7.6%. The nominal COP of the heat pump is 4.2 (condenser exhaust temperature of 60°C and evaporator supply temperature of 15°C). Experimentally, a COP of 4.21 (condensation temperature of 61°C and evaporation temperature of 21°C). is achieved in heat pump mode and a global ORC efficiency of 5.7% is obtained in ORC mode (condenser exhaust temperature of 25°C and evaporator supply temperature of 88°C). [less ▲]

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See detailDIMENSIONNEMENT ET EXPÉRIMENTATION D’UNE UNITÉ POMPE À CHALEUR / ORC RÉVERSIBLE
Dumont, Olivier ULg; Quoilin, Sylvain ULg; Lemort, Vincent ULg

Conference (2014)

L’union européenne doit réduire les émissions de gaz à effet de serre de 80% par rapport au niveau des années 90 d’ici 2020. Les ménages représentent 27% de la consommation finale. Dans ce cadre, les ... [more ▼]

L’union européenne doit réduire les émissions de gaz à effet de serre de 80% par rapport au niveau des années 90 d’ici 2020. Les ménages représentent 27% de la consommation finale. Dans ce cadre, les bâtiments dont la consommation d’énergie est quasi nulle (NZEB – Nearly Zero Energy Building) sont d’une importance considérable. A partir de 2019, tous les nouveaux bâtiments devront présenter une production d’énergie renouvelable supérieure à la consommation d’énergie primaire. C’est dans ce cadre que le concept de PAC/ORC prend tout son sens. Ce système innovant comprend une pompe à chaleur eau/eau (PAC) reliée à un toit solaire et à un échangeur de chaleur géothermique. Cette pompe à chaleur est également capable d'inverser son cycle et de fonctionner comme un Cycle Organique de Rankine (ORC). En utilisant le toit solaire comme source de chaleur, une grande quantité de chaleur est générée tout au long de l'année. Cette chaleur est utilisée en priorité pour couvrir les besoins de chauffage annuels et le surplus de chaleur généré au cours de l'été est utilisée pour produire de l'électricité dans l’unité PAC / ORC. L’article s’articule en 4 parties. Tout d’abord, l’introduction présente les trois modes de fonctionnement. Ensuite, les modèles des composants et l’évaluation des performances au point nominal de conception sont décrits. Par après, le dimensionnement et le choix des composants sont réalisés sur bases de simulations annuelles avec un pas de temps d’une heure. Enfin, les premiers résultats expérimentaux sont présentés. Un rendement de 5,7% est atteint en mode ORC (avec une température de condensation de 25°C et une température d’évaporation de 88°C) alors qu’un COP de 4,2 est obtenu en mode pompe à chaleur (avec une température de condensation de 61°C et une température d’évaporation de 21°C). [less ▲]

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