References of "Lemort, Vincent"
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See detailModeling and control of waste heat recovery Rankine based systems for heavy duty trucks
Grelet, Vincent; Dufour, Pascal; Nadri, Madiha et al

in Proceedings of the 9th International Symposium on Advanced Control of Chemical Processes (2015)

This paper presents a control oriented model development for waste heat recovery Rankine based control systems in heavy duty trucks. Waste heat recovery systems, such as Rankine cycle, are promising ... [more ▼]

This paper presents a control oriented model development for waste heat recovery Rankine based control systems in heavy duty trucks. Waste heat recovery systems, such as Rankine cycle, are promising solutions to improve the fuel efficiency of heavy duty engines. Due to the highly transient operating conditions, improving the control strategy of those systems is an important step to their integration into a vehicle. The system considered here is recovering heat from both EGR and exhaust in a serial arrangement and use a mixture of water and ethanol as working fluid. The paper focuses on a comparison of a classical PID controller which is the state of the art in the automotive industry and a nonlinear model based controller in a simulation environment. The nonlinear model based controller shows better performance than the PID one and ensures safe operation of the system. [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 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

in Elimar, Frank; Philippe, Papillon (Eds.) Proceedings of the ISES EuroSun 2014 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 detailThermoCycle: A Modelica library for the simulation of thermodynamic systems
Quoilin, Sylvain ULg; Desideri, Adriano ULg; Wronski, Jorrit et al

in Proceedings of the 10th International Modelica Conference 2014 (2014)

This paper presents the results of an on-going project to develop ThermoCycle, an open Modelica library for the simulation of low-capacity thermodynamic cycles and thermal systems. Special attention is ... [more ▼]

This paper presents the results of an on-going project to develop ThermoCycle, an open Modelica library for the simulation of low-capacity thermodynamic cycles and thermal systems. Special attention is paid to robustness and simulation speed since dynamic simulations are often limited by numerical constraints and failures, either during initialization or during integration. Furthermore, the use of complex equations of state (EOS) to compute thermodynamic properties significantly decreases the simulation speed. In this paper, the approach adopted in the library to overcome these challenges is presented and discussed. [less ▲]

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See detailExperimental investigation of an ORC system for a micro-solar power plant
Dickes, Rémi ULg; Dumont, Olivier ULg; Declaye, Sébastien ULg et al

in Proceedings of the 2014 Purdue Conferences (2014)

Because of the depletion of fossil fuels and global warming issues, the world energy sector is undergoing various changes towards increased sustainability. Among the different technologies being developed ... [more ▼]

Because of the depletion of fossil fuels and global warming issues, the world energy sector is undergoing various changes towards increased sustainability. Among the different technologies being developed, solar energy, and more specifically CSP (Concentrated Solar Power) systems are expected to play a key role to supply centralized loads and off-grid areas in the medium-term. Major performance improvements can be achieved by implementing advanced control strategies accounting for the transient and random nature of the solar heat source. In this context, a lab-scale solar power plant has been designed and is under construction for experimental purposes and dynamic analysis. The test rig includes an Organic Rankine Cycle (ORC) unit, a field of parabolic trough collectors and a thermal energy storage system. This paper presents the results of an experimental campaign conducted on the ORC module alone. This power unit, designed for a 2.8 kW net electrical output, consists of two scroll expanders in series, an air-cooled condenser, a recuperator, a volumetric pump and an oil-heated evaporator. The ORC engine is constructed using standard mass manufactured components from the HVAC industry, this practice reducing considerably the system cost. The overall unit performance and components effectiveness are presented in different operating conditions and relevant empirical correlations are derived to be implemented in a steady state model of the ORC unit. [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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