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See detailEconomic and environmental comparison of a centralized and a decentralized heating production for a district heating network implementation
Resimont, Thibaut; Altés Buch, Queralt; Sartor, Kevin; Dewallef, Pierre

in 10th International Conference on System Simulation in Buildings, Liège, Belgium, 10-12 Deember 2018 (2018, December 12)

District heating networks seem to be a promising solution for heating delivery by using a centralized production unit instead of local gas boilers or heat pumps in each house. The use of several available heat sources, like waste incinerators for example, enables to reduce global primary energy consumption and to have a better control on pollutants emissions and greenhouse gases emissions than with a local heating production. The main drawback of district heating networks is the consequent initial investment cost for pipes and substations. It is thus interesting to achieve a fair comparison between a centralized heating production unit including a district heating network and a decentralized one with heating units in each house. The comparison is based on the IEA EBC Annex 60 case study made up of a small neighborhood of 24 dwellings combined with a greenhouse characterized by specific energy consumption profiles. For the centralized heating production, a waste incinerator and a gas boiler are considered as heating sources while gas boilers or heat pumps are taken into account for a decentralized heating production. In both cases, an economic and environmental study is achieved to determine the optimal scenario between a centralized and a decentralized heating production.

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See detailDéveloppement d'un outil de simulation et d'analyse technico-économique et environnementale d'un réseau de chaleur
Sartor, Kevin

Doctoral thesis (2018)

The first part of this doctoral thesis is composed of 6 chapters. Chapter 1 summarizes the different contexts in which the research work takes place. The global energy context for primary energy consumption related to heating and cooling buildings is firstly detailed. Indeed, this work focuses on the supply of buildings through district heating networks which are then detailed. To feed these district heating networks, the use of biomass and cogeneration units are also discussed in this first chapter. Chapter 2 presents the case study used to test the methodology developed in the research work. Using its specifications and the concepts introduced in chapter 1, general objectives are defined. Chapter 3 delineates the objectives of this research work on the basis of those set out in chapter 2. To achieve this, the different methods used are detailed and referenced through the scientific articles constituting the part 2 of this manuscript. Finally, the computer tools used to achieve these objectives are also briefly discussed. Chapter 4 presents the results of scientific articles 3, 4 and 8 of the part 2 of this manuscript concerning thermal energy transport modeling. Article 3, based on the limitations observed for a modeling method (finite volumes) commonly used for thermal energy transport modeling, details an alternative method of thermal energy transport simulation in the Matlab software language. This method considers not only the heat losses to the pipe environment but also the thermal inertia of the pipe whose influence on energy transport is demonstrated. Article 4 validates this approach experimentally in a laboratory test bench and on a portion of a heating network pipe of the case study. Article 8 establishes a state of the art of the different thermal energy transport modelling methods which concludes on the requirement to use an alternative method for the dynamic estimation of heat losses and thermal energy transport of a pipeline. This article proposes to use the method envisaged in article 3 by adapting it to the Modelica language. Furthermore, this alternative method is validated on the laboratory installation used in the experimental validation of article 4 as well as a portion of an existing heating network consisting of several consumers. Chapter 5 presents the results obtained for the analysis of a heating network, which are summarized in the scientific articles numbered 1, 2, 5, 6, 7 and 9 in part 2 of this manuscript, and supplements are also discussed where required. Article 1 presents a detailed modeling of biomass and natural gas combustion in order to estimate the emissions of several pollutants while focusing on the formation of nitrogen oxides. Article 2 presents a methodology to estimate the cost of heat and the carbon dioxide emissions balance of a heating network and compares this heating system with other alternative technologies. To achieve this objective, several models are detailed and validated experimentally in order to estimate the performances of the various installations constituting a heating network (boilers, cogeneration unit, heating network). Finally, several scenarios to improve the heating network and the cogeneration unit are considered and compared using the methodology developed. Article 6 and Article 7 consider alternative scenarios for reducing the cost of heating the heating network on the basis of the models developed in Article 2. Article 6 investigates the addition of thermal energy storage in order to maximize the use of a cogeneration unit feeding the heating network. Energy storage is considered in two forms: a hot water buffer storage tank placed close to the network and an adapted regulation allowing the use of the thermal inertia of the heating network. In addition, short-term and seasonal energy storage are considered to verify their relevance to the context of the heating network under study. On the basis of the results obtained, the subsidy policy linked to the use of the cogeneration unit is analyzed in order to determine its adequacy in the context of the case study. Article 7, for its part, envisages the addition of a high-temperature heat pump at a strategic point in the heating network that requires a hot water supply temperature to generate steam. This scenario is based on the assumption that by reducing the average temperature of the network thanks to this heat pump, it would be possible to limit the losses to the environment of the network and thus potentially to reduce the associated costs and the environmental footprint. Article 5 complements the analysis of heating networks by detailing a methodology to estimate the energy consumption and the energetic and environmental performances of different heating systems, including heating networks, in order to compare these solutions as a whole. Chapter 6 summarizes the findings of the research and offers perspectives for research. The second part of this doctoral thesis is composed of the scientific articles that were previously discussed and a section devoted to correct an error present in one of the scientific articles and to specify an aspect related to the cogeneration unit studied, namely the evolution of its rated power during the studies.

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See detailRaspberry Pi et ESP8266 - Domotisez votre habitation
Sartor, Kevin

Book published by Editions ENI (2018)

Ce livre s'adresse à toute personne souhaitant réaliser elle-même une installation domotique à moindre coût pour améliorer le confort de son domicile (gestion de l'énergie, des luminaires…) et le rendre intelligent et connecté. Pour réaliser cette installation, l'auteur s'appuie sur le nano-ordinateur Raspberry Pi et sur le microcontrôleur ESP8266. Après une introduction générale portant sur les possibilités offertes par une installation domotique, le lecteur découvre un aperçu des compteurs généralement disponibles dans son habitation (eau, électricité, gaz…) et la manière de les rendre communicants. Une liste de capteurs et actionneurs complémentaires, les « organes » de l'installation, est étudiée tout en sensibilisant le lecteur aux erreurs de mesure. L'auteur détaille ensuite l'installation et la configuration du matériel et des logiciels nécessaires pour la réalisation des premiers projets qui constitueront l'installation domotique. Il poursuit avec l'étude des capacités offertes par un ESP8266 pour piloter les différents dispositifs connectés (possibilités de mesure, d'interaction…). Des projets plus complexes, tirés de l'expérience personnelle et professionnelle de l'auteur, sont ensuite proposés à l'étude afin d'améliorer le confort de l'occupant et les consommations d'énergie, et de piloter de nombreux actionneurs (ventilateur, électrovanne, lampe LED…). Un dernier chapitre clos l'ensemble en présentant certaines notions d'électronique et de programmation plus élaborées permettant de fiabiliser les dispositifs et offrant la possibilité au lecteur de personnaliser davantage son installation domotique. Des éléments complémentaires sont disponibles en téléchargement sur le site www.editions-eni.fr.

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See detailExperimental validation of heat transport modeling in large solar thermal plant.
Sartor, Kevin; Dickes, Rémi; Resimont, Thibaut; Dewallef, Pierre

Scientific conference (2018, June)

Solar thermal plants are often considered as a convenient and environmental-friendly way to supply heat to buildings or low temperature industrial processes. Some modelling techniques are required to assess the dynamic behaviour of solar thermal plants in order to control them correctly. This aspect is reinforced while large plants are considered. Indeed some atmospheric conditions as local clouds could have significant influence on the outlet temperature of the solar field. A common modelling approach to assess the heat transport in pipes is the one-dimensional finite volume method. However previous work shows limitations in the assessment of the temperatures and in the computational time require simulating large pipe networks. In this contribution, a previous alternative method developed and validated in a district heating network is used and extended to a solar thermal plant considering the thermal solar gain and the inertia of the pipes. The present contribution intends to experimentally validate this model on an existing solar plant facility available at the Plataforma Solar de Almeria in Spain.

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See detailThermo-Economic Evaluation of a Virtual District Heating Network Using Dynamic Simulation
Resimont, Thibaut; Sartor, Kevin; Dewallef, Pierre

Scientific conference (2018, June)

In the current context of energy transition, district heating systems are considered as a convenient yet efficient solution to reduce both primary energy consumption and greenhouse gases emissions. The use of locally available alternative heat sources, as for example the heat rejected by waste incinerators, constitutes an opportunity to valorize low-grade heat. Despite a higher initial investment cost, waste incinerators present the advantage to have a zero fuel cost that balances this initial capital expense. In the present contribution, a reference case study based on the IEA EBC Annex 60 framework is used as a first attempt to explore dynamic effects related to the distribution of heat through district heating networks. It consists of a small set of reference dwellings with different heating profiles depending on the type of buildings and their level of insulation. The costs for the different operating scenarios and the consequent advantages of a combined heat and power waste incinerator as a heat source are determined. This paper illustrates the use of a plug flow dynamic model intended to predict the heat transport delay, the heat losses and the pumping work due to long piping instead of the classical steady-state approach usually used for district heating networks profitability assessment. A comparative assessment of both the unit cost of heat and CO2 emissions savings is performed for two different heating technologies, namely a combined heat and power waste incinerator combined to backup boilers and a natural gas boiler.

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See detailA comparative study for simulating heat transport in large district heating networks
Sartor, Kevin; Thomas, David; Dewallef, Pierre

in International Journal of Heat and Technology (2018), 36(1), 301--308

District heating networks are a convenient, economic and environmental-friendly way to supply heat to buildings connected to a central heating plant. However, the control of such a system becomes challenging if the total length of the network reaches several kilometers because the travel time of the information into the system is over hours. One solution consists in instrumenting all the parts of the network and performing a closed loop control to optimize the temperature and the mass flow rate supplied to every single consumption point. However this solution is generally expensive and difficult to implement in existing networks. What is proposed in this paper is to dynamically model the heat waves in the network to determine the temperatures and mass flow rates at key locations considering the ambient losses and the pipe thermal inertia. A study is performed to check the possibility to use the one-dimensional finite volume method to simulate heat waves propagation. First, an adiabatic pipe is considered as a reference test case to determine the limitations of this method. The results are compared to a 2D computational fluid dynamic simulation and numerical diffusion is exhibited for low spatial discretization. Therefore, an improved alternative model is developed to overcome this problem.

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See detailIntegration of heat storage system into district heating networks fed by a biomass CHP plant
Sartor, Kevin; Dewallef, Pierre

in Journal of Energy Storage (2018), 15

Biomass Combined Heat and Power (CHP) plants connected to district heating networks (DHN) are recognized as a very good opportunity to increase the share of renewable sources into energy systems. However, as CHP plants are not optimized for electricity production, their operation is profitable only if a sufficient heat demand is available throughout the year. On the other hand, these plants often work for baseline operations and back-up boilers are used to supply the peak demand. To extend the use of the CHP plants and reduce costs, conventional fuel use and emissions, it is proposed to study the feasibility of using the DHN itself or additional high temperature heat storage as retrofit of an existing CHP plant. This work is based on a simple and effective methodology that provides accurate estimations of economic, environmental and energetic performances of CHP plants connected to district heating networks. The focus is performed on the integration of the heat storage as retrofit of existing DHN considering the local policies. The DHN of the University in Liège (Belgium) is used as an application framework to demonstrate the effectiveness of the selected approach. The potential energy, pollutant emissions savings and resulting energy costs are estimated and the current policy limitations will be discussed.

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See detailPerformance analysis of a mini exhaust air heat pump integrated into a low energy detached house: experimental on-site performance
Ransy, Frédéric; Sartor, Kevin; Gendebien, Samuel; Lemort, Vincent

in Proceedings of the 5th International High Performance Buildings Conference at Purdue (2018)

This paper presents the on-site performance of a mini exhaust air heat pump integrated into a low energy detached house situated in Belgium. The system consists of five components: a simple exhaust ventilation system, an exhaust air heat pump, a backup electrical resistance for space heating only, a domestic hot water storage tank and fan-coil units to heat the building. In that system, the heat source of the heat pump is the air from the ventilation system and the heat pump heating capacity is limited to 1500 W. During the night, the exhaust air heat pump produces the sanitary hot water, which is stored in a water tank. Consequently, the totality of the domestic hot water is produced by the heat pump. During the day, the heat pump can also be used to heat the building. Nevertheless, only a part of the energy requirements related to heating are covered by the machine, due to the limited heating capacity. The remaining heating requirements are covered by the backup electrical resistance. For this reason, this machine is particularly suitable for apartment buildings characterized by a low heating demand and a significant energy demand related to domestic hot water production. In the first part of the paper, the characteristics of the building case study and the different components of the system are presented. The second part of the paper describes the sensors placed in the building used to measure the on-site performance of the machine. In the third part of the paper, the on-site performance of the machine is presented. The influence of the main variables (exhaust water temperature, supply air temperature, outside temperature) on the performance is also discussed. In the last part of the paper, the performance of the whole system is estimated for a typical meteorological year. The estimation is based on the Energetic Performance of Building certificate of the building, and on empirical relationships established with the on-site performance of the machine.

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See detailSimulation Models to Size and Retrofit District
Sartor, Kevin

in Energies (2017), 10(12),

District heating networks are considered as convenient systems to supply heat to consumers while reducing CO2 emissions and increasing renewable energies use. However, to make them as profitable as possible, they have to be developed, operated and sized carefully. In order to cope with these objectives, simulation tools are required to analyze several configuration schemes and control methods. Indeed, the most common problems are heat losses, the electric pump consumption and the peak heat demand while ensuring the comfort of the users. In this contribution, a dynamic simulation model of all the components of the network is described. It is dedicated to assess some energetic, environmental and economic indicators. Finally, the methodology is used on an existing application test case namely the district heating network of the University

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See detailExperimental validation of heat transport modelling in district heating networks.
Sartor, Kevin; Dewallef, Pierre

in Energy (2017), 137

District heating networks (DHN) are generally considered as a convenient, economic and environmental-friendly way to supply heat to a large amount of buildings. Some modelling methods are required to consider the dynamic behaviour of district heating networks to design them correctly, spare the investment costs and limit the heat losses related to the use of a too high operating temperatures. For the same reasons, the DHN control or retrofit of installations also requires the assessment of the DHN dynamic behaviour. To achieve this, the heat transport in DHN, which is one of the key issues in the behaviour of a whole centralized heating system, has to be correctly modelled. Previous work evidenced current limitations of one dimensional finite volume method to model heat transport in pipes and proposed an alternative method considering the thermal losses and the inertia of the pipes. The present contribution intends to experimentally validate this model on a test rig available at the Thermodynamics laboratory of the University of Liège (ULg, Belgium) and on an existing district heating network. For both experimental facilities, the current model shows good agreement between the experimental data and the simulation results for a large range of water velocities. Moreover, it is shown that the thermal inertia of the pipe has a significant influence on the outlet pipe temperature profile.

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See detailExergy analysis applied to performance of buildings in Europe
Sartor, Kevin; Dewallef, Pierre

in Energy and Buildings (2017), 148

Energy performance of buildings generally assesses the energy consumption of buildings such as heating, domestic heat water, ventilation systems, etc. However, this approach is based on the first law of thermodynamics and considers only the quantity of energy used without considering its ‘quality’ and leads to a lack of information about the energy conversion processes. This is particularly true in the new low-energy buildings where sometimes high temperatures sources are used to meet low-temperature needs. The exergy analysis of a system, based on first and second thermodynamic laws, can be used to overcome this. In this work, it is proposed to compare the energy and the exergy consumption and the related CO2 emissions of several kinds of buildings to determine the best systems in terms of energy and exergy needs. The energy demand calculations are performed using the official software available in Belgium and some assumptions are implemented to consider the exergy approach. As exergy calculations require a reference state, some different climatic conditions are also investigated. Finally, some conclusions are discussed to rank the sources of energy and their related exergy losses.

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See detailArduino: une carte électronique aux multiples possibilités
Sartor, Kevin

Scientific conference (2017, March 08)

Formation destinée à l'utilisation des cartes électroniques "Arduino". Au programme une brève introduction, une liste de possibilités non exhaustive, le tout suivi de cas pratiques et de conseils pour la réalisation de votre premier projet.

See detailOptimized integration of heat storage into district heating networks fed by a biomass CHP plant.
Sartor, Kevin

in Proceedings (2017, February 28)

Biomass Combined Heat and Power (CHP) plants connected to district heating networks (DHN) are recognized as a very good opportunity to increase the share of renewable sources into energy systems. However, as CHP plants are not optimized for electricity production, their operation is profitable only if a sufficient heat demand is available throughout the year. On the other hand, these plants often work for baseline operation and back-up boilers are used to supply the peak demand. To extend the use of the CHP plants and reduce costs, conventional fuel use and emissions, it is proposed to study the feasibility of using additional high temperature heat storage as retrofit of an existing CHP plant. This work is based on a simple and effective methodology that provides accurate estimations of economic, environmental and energetic performances of CHP plants connected to district heating networks. The DHN of the University in Liège (Belgium) is used as an application framework to demonstrate the effectiveness of the selected approach. The potential energy and pollutant emissions savings and resulting energy costs are estimated and the current policy limitations will be discussed.

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See detailImproved district heating network operation by the integration of high-temperature heat pumps
Sartor, Kevin; Lemort, Vincent; Dewallef, Pierre

in International Journal of Sustainable Energy (2017)

Biomass combined heat and power (CHP) plants connected to district heating networks are a very good opportunity to increase the share of renewable sources into energy systems. Frequently, important consumers are connected to ensure a stable base heat demand throughout the year but they often have higher requirements in terms of temperature (i.e. steam), which involves a high level of temperature in the district heating network during the whole year and high levels of heat losses in the network. This contribution presents the possibility to decrease the level of temperature at which the district heating network operates and to use high-temperature heat pumps connected locally at the consumption point to produce steam when it is required. An investigation of the global design and integration through thermodynamic simulation models is realised for the University of Liège district heating network. This study is intended to determine the heat pump coefficient of performance and, therefore, to assess the balance between the savings in terms of heat losses and the additional heat pump electricity consumption. © 2017 Informa UK Limited, trading as Taylor & Francis Group

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See detailEffect of undisturbed ground temperature on the design of closed-loop geothermal systems: A case study in a semi-urban environment
Radioti, Georgia; Sartor, Kevin; Charlier, Robert; Dewallef, Pierre; Nguyen, Frédéric

in Applied Energy (2017)

This paper presents temperature measurements in four Borehole Heat Exchangers (BHEs), equipped with fiber optics and located in a semi-urban environment (campus of the University of Liege, Belgium). A 3D numerical model is also presented to simulate the heat loss from the surrounding structures into the subsurface. The mean undisturbed ground temperature was estimated from data during the preliminary phase of a thermal response test (water circulation in the pipe loops), as well as from borehole logging measurements. The measurements during water circulation can significantly overestimate the ground temperature (up to 1.7 C in this case study) for high ambient air temperature during the test, resulting in an overestimation of the maximum extracted power and of the heat pump coefficient of performance (COP). To limit the error in the COP and the extracted power to less than 5%, the error in the undisturbed temperature estimation should not exceed ±1.5 °C and ±0.6 °C respectively. In urbanised areas, configurations of short BHEs (length < 40 m) could be economically advantageous (decreased installation and operation costs) compared to long BHEs, especially for temperature gradient lower than 0.05 °C/m.

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See detailEnergetic and Environmental Performances of a Domestic Hot Water Condensing Boiler Fired by Wood Pellets
Ngendakumana, Philippe; Gabriele, Fabian; Restivo, Yannick; Sartor, Kevin

in Energy Procedia (2017)

In order to assess the performances of the domestic heating boilers with a CE mark, a wood pellets fired condensing boiler has been purchased and installed in the Laboratory for tests. The objective of the study was not only to check the announced performances, but mainly to investigate the influence of the different parameters affecting the functioning of the boiler, the thermal efficiency and the pollutants (NOx and CO) emission being aimed at. Tests have been performed to study the influence of the cycling frequency of the burner functioning, the overall excess air, the return water temperature, and the output power of the boiler. As announced by the manufacturer, the tested boiler fulfils the requirements of the Blue Angel Label, but the recommended value for the excess air (1.2) can be reduced to a value of about 0.4 without excessive emissions of CO. The boiler could perform better if the ON period of the cycle of the burner is increased even better if the OFF period is suppressed. The NOx are mainly formed from the nitrogen content of the pellets and their emissions can only be reduced by a lower nitrogen content of the pellets than the limit stated in the standard. Random peaks observed in the evolution of CO, the boiler being operating in steady state regime, are attributed to the combustion process of pellets which is a non-continuous process by nature.

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See detailDynamic equation-based thermo-hydraulic pipe model for district heating and cooling systems
Heijde, B. Van Der; Fuchs, M.; Tugores, C. Ribas; Schweiger, G.; Sartor, Kevin; Basciotti, D.; Müller, D.; Nytsch-Geusen, C.; Wetter, M.; Helsen, L.

in Energy Conversion and Management (2017), 151

Simulation and optimisation of district heating and cooling networks requires efficient and realistic models of the individual network elements in order to correctly represent heat losses or gains, temperature propagation and pressure drops. Due to more recent thermal networks incorporating meshing decentralised heat and cold sources, the system often has to deal with variable temperatures and mass flow rates, with flow reversal occurring more frequently. This paper presents the mathematical derivation and software implementation in Modelica of a thermo-hydraulic model for thermal networks that meets the above requirements and compares it to both experimental data and a commonly used model. Good correspondence between experimental data from a controlled test set-up and simulations using the presented model was found. Compared to measurement data from a real district heating network, the simulation results led to a larger error than in the controlled test set-up, but the general trend is still approximated closely and the model yields results similar to a pipe model from the Modelica Standard Library. However, the presented model simulates 1.7 (for low number of volumes) to 68 (for highly discretized pipes) times faster than a conventional model for a realistic test case. A working implementation of the presented model is made openly available within the IBPSA Modelica Library. The model is robust in the sense that grid size and time step do not need to be adapted to the flow rate, as is the case in finite volume models.

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See detailFiber-optic temperature measurements in closed-loop geothermal systems: A case study in heterogeneous bedrock
Radioti, Georgia; Delvoie, Simon; Sartor, Kevin; Nguyen, Frédéric; Charlier, Robert

in Energy Geotechnics (2016, August)

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See detailFeasibility study of burning neat jatropha oil into a vaporizing burner for household applications.
Sartor, Kevin; Makaire, Danielle; Fontaine, Jean-Marie; Ngendakumana, Philippe

in Proceedings (2016, August)

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See detailExperimental validation of heat transport modeling in district heating networks
Sartor, Kevin

in Proceedings of Conference (2016)

District heating networks (DHN) are generally considered as a convenient, economic and environmental-friendly way to supply heat to a large amount of buildings. Some modelling technics are required to consider the dynamic behaviour of district heating network to design them correctly, spare investment costs and limit the heat losses related to the use of a too high operating temperature. For the same reasons, the DHN control or retrofit of installations also requires the assessment of the DHN dynamic behaviour. To achieve this, the heat transport in DHN, which is one of the key issues in the behaviour of a whole centralized heating system, has to be correctly modelled. Previous work evidenced current limitations of one dimensional finite volume method to model heat transport in pipes and proposed an alternative method considering the thermal losses and the inertia of the pipes. The present contribution intends to experimentally validate this model on a test rig facility available in the Thermodynamics laboratory of the University of Liège (ULg, Belgium) and on an existing district heating network. For both experimental facilities, the current model shows good agreement between experimental data and simulation results for a large range of water velocities. Moreover, it is shown that the thermal inertia of the pipe has a significant influence on the outlet pipe temperature profile.

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See detailExergy analysis applied to performance of buildings in Europe
Sartor, Kevin; Dewallef, Pierre

in Proceedings (2016)

Energy performance of buildings generally assesses the energy consumption of buildings such as heating, domestic heat water, ventilation systems... However, this approach is based on the first law of thermodynamics and considers only the quantity of energy used without considering its “quality” and leads to a lack of information about the energy conversion processes. This is particularly true in the new low-energy buildings where sometimes high temperatures sources are used to meet low-temperature needs. The exergy analysis of a system, based on first and second thermodynamic laws, can be used to overcome this. In this work, it is proposed to compare the energy and the exergy consumption of several kinds of buildings to determine the best systems in terms of energy and exergy needs. The energy demand calculations are performed using the official software available in Belgium and some assumptions are implemented to consider the exergy approach. As exergy calculations require a reference state, some different climatic conditions are also investigated. Finally, some conclusions are discussed to rank the sources of energy and their related exergy losses.

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See detailExergetic, environmental and economic analysis of a biomass cogeneration plant connected to a district heating network.
Sartor, Kevin; Dewallef, Pierre

in Renewable Energy in the Service of Mankind Vol II (2015)

When a district heating network is fed by natural gas boilers (or biomass boilers), the selection of the network temperature level has a slight influence on the boiler efficiency which means that producing at low temperature allows only to decrease the heat losses through the network. However when a cogeneration plant based on a Rankine cycle is used, lowering the network temperature not only decreases the heat losses but also increase the electrical efficiency while decreasing the thermal efficiency. This aspect is very often overlooked when the quality of a cogeneration plant is assessed by the cogeneration efficiency namely the sum of the electrical and thermal efficiency which is misleading for decision makers. In this contribution, an existing cogeneration plant connected to a district heating network installed on the University Campus in Liège (Belgium) is used as an application test case. Based on actual operational and economic data, a detailed economic evaluation is carried out which is supported by a calibrated simulation model of the whole installation in order to study the influence of the network temperature level. As a second step, the simulation model is used again to perform a detailed exergetic analysis intended to give physical insights to the economical study. This results in a broader discussion on the several methods to assess the quality of cogeneration plants and the opportunity to develop such a technology together with district heating networks.

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See detailWe gme P08: Fiber-optic temperature profiles analysis for closed-loop geothermal systems-a case study
Radioti, Georgia; Delvoie, Simon; Sartor, Kevin; Nguyen, Frédéric; Charlier, Robert

in Second EAGE Workshop on Geomechanics and Energy: The ground as energy source and storage (2015, October)

In order to study the behaviour of shallow closed-loop geothermal systems four borehole heat exchangers equipped with fiber optics were installed on the campus of the University of Liege (Liege, Belgium) over a surface area of 32m². This paper presents the analysis of continuous, high-resolution temperature profiles measured along the boreholes length. The undisturbed ground temperature measurements indicate heat loss from ground structures located close to the boreholes. A 3D numerical model is presented to reproduce the measured temperature profiles. Temperature profiles during hardening of the grouting material indicate extended fractured zones in the rock mass. Temperature measurements during the recovery phase of a Distributed Thermal Response Test indicate the succession of rock layers with different mineral content. The results are in good agreement with those of the borehole televiewer logging method. The presented analysis could provide information on bedrock heterogeneity, on the anisotropic thermal behaviour of the rock mass and on the ground temperature variations due to heat loss from ground structures. These information could significantly contribute to the long-term behaviour prediction of the geothermal system and the geothermal reservoir potential.

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See detailAnnex 60 : subtask 2.2 - Modeling heat transport in district heating networks
Sartor, Kevin

Report (2015)

One subtask of the Annex 60 (Task 2.2) consists in the modeling of district composed by thermal and electric networks. In this contribution, several modeling techniques are investigated to assess the behavior of the thermal part of the district heating network. These modeling techniques are compared to find the best modeling approach.

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See detailA comparative study for simulating heat transport in large district heating network
Sartor, Kevin; Thomas, David; Dewallef, Pierre

in Proceedings of ECOS 2015 (2015, June 29)

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See detailAnnex 60 : subtask 2.2 - Connection methods in district heating networks
Sartor, Kevin

Scientific conference (2015, April 21)

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See detailLes vélos électriques, une solution d'avenir?
Sartor, Kevin

Learning material (2015)

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See detailSimulation and optimization of a CHP biomass plant and district heating network
Sartor, Kevin; Quoilin, Sylvain; Dewallef, Pierre

in Applied Energy (2014), 130

Biomass Combined Heat and Power (CHP) plants connected to district heating (DH) networks are recognized nowadays as a very good opportunity to increase the share of renewable sources into energy systems. However, as CHP plants are not optimized for electricity production, their operation is profitable only if a sufficient heat demand is available throughout the year. Most of the time, pre-feasibility studies are based on peak power demand and business plans only assume monthly or yearly consumption data. This approach usually turns out to overestimate the number of operating hours or oversize the plant capacity. This contribution presents a methodology intended to be simple and effective that provides accurate estimations of economical, environmental and energetic performances of CHP plants connected to district heating networks. A quasi-steady state simulation model of a CHP plant combined with a simulation model of the district heating network installed on the Campus of the University in Liège (Belgium) is used as an application framework to demonstrate the effectiveness of the selected approach. Based on the developed model and actual consumption data, several scenarios for energy savings are considered and ranked. The potential energy savings and resulting energy costs are estimated enabling more general conclusions to be drawn on the opportunity of using district heating networks in urban districts for Western Europe countries.

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See detailExergetic, environmental and economic analysis of a biomass cogeneration plant connected to a district heating network.
Sartor, Kevin

in Book of abstracts of WREC2014 (2014, August 05)

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See detailPrediction of SOx and NOx Emissions from a Medium Size Biomass Boiler Biomass and Bioenergy
Sartor, Kevin; Restivo, Yannick; Ngendakumana, Philippe; Dewallef, Pierre

in Biomass and Bioenergy (2014), 65

While small and medium size biomass combined heat and power (CHP) plants (i.e., up to 5 MW of electrical rated power) represent an attractive option to exploit locally available biomass resources at low cost, the corresponding investment per unit of rated power significantly rises when the installed power decreases. In these cases, secondary pollutant emissions control measures are most of the time not economically viable and primary emissions control must be used alone to avoid the formation of undesired compounds such as $NO_x$ and $SO_x$. Primary control measures require the careful optimization of fuel quality and combustion process. For plant operators, being able to accommodate biomass quality changes in order to minimize the fuel cost can be of great importance in order to guarantee the profitability of the plant. This contribution is dedicated to the development of a zero-dimensional (input-output) combustion simulation model able to predict the pollutants emissions resulting from complete and incomplete combustion with respect to varying combustion operation (ambient temperature, humidity, fumes recirculation,..). This tool is intended to be integrated in a global simulation model of the CHP plant and the attached district heating network installed on the University campus in Liège. Doing so, the plant operation can be optimized with respect to economic as well as environmental and energetic aspects (3E approach) thus ensuring the sustainability of the approach.

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See detailImproved District Heating Network Operation by the Integration of High Temperature Heat Pumps
Sartor, Kevin; Lemort, Vincent; Dewallef, Pierre

in Digital proceedings of the 8th Conference on Sustainable Development of Energy, Water and Environment Systems - SDEWES (2013, September 23)

Biomass Combined Heat and Power (CHP) plants connected to district heating networks are a very good opportunity to increase the share of renewable sources into energy systems. Frequently, important consumers are connected to ensure a stable base demand of heat throughout the year but they often have higher requirements in terms of temperature (i.e., steam) which involves high level of temperatures in the district heating network during the whole year and high levels of heat losses in the network. This contribution presents the possibility to decrease the level of temperature at which the district heating network operates and to use high temperature heat pumps connected locally at the consumption point to produce steam when needed. An investigation of the global design and integration through thermodynamic simulation models is realized for the University of Liège district heating network. This study is intended to determine the heat pump coefficient of performance and, therefore, to assess the balance between the savings in terms of heat losses and the additional heat pump electricity consumption.

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See detailSimulation and optimization of a CHP biomass plant and district heating network
Sartor, Kevin; Quoilin, Sylvain; Dewallef, Pierre

Conference (2013, July)

Biomass Combined Heat and Power (CHP) plants connected to district heating (DH) networks are recognized nowadays as a very good opportunity to increase the share of renewable sources into energy systems. However, as CHP plants are not optimized for electricity production, their operation is profitable only if a sufficient heat demand is available throughout the year. Most of the time, pre-feasibility studies are based on peak power demand and business plans only assume monthly or yearly consumption data. This approach usually turns out to overestimate the number of operating hours or oversize the plant capacity. This contribution presents a methodology intended to be simple and effective that provides accurate estimations of economical, environmental and energetic performances of CHP plants connected to district heating networks. A quasi-steady state simulation model of a CHP plant combined with a simulation model of the district heating network installed on the Campus of the University in Liège (Belgium) is used as an application framework to demonstrate the effectiveness of the selected approach. Based on the developed model and actual consumption data, several scenarios for energy savings are considered and ranked. The potential energy savings and resulting energy costs are estimated enabling more general conclusions to be drawn on the opportunity of using district heating networks in urban districts for Western Europe countries.

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See detailOptimization of the operating conditions of an existing biomass CHP plant with respect to pollutants levels
Sartor, Kevin; Restivo, Yannick; Ngendakumana, Philippe; Dewallef, Pierre

in Proceedings of 21st Biomass Conference and Exhibition (2013, June 03)

While small and medium size biomass combined heat and power plants (i.e., up to 5 MW of electrical rated power) represent an attractive option to exploit locally available biomass resources at low cost, the corresponding investment per unit of rated power significantly rises when the installed power decreases. In these cases, secondary pollutant emissions control measures are most of the time not economically viable and primary emissions control must be used alone to avoid the formation of undesired compounds such as $NO_x$ and $SO_x$. Primary control measures require the careful optimization of fuel quality and combustion process. For plant operators, being able to accommodate biomass quality changes in order to minimize the fuel cost can be of great importance in order to guarantee the profitability of the plant. This contribution is dedicated to the development of zero-dimensional (input-output) combustion simulation model able to predict the pollutants emissions resulting from complete and incomplete combustion with respect to varying combustion operation (ambient temperature, humidity, fumes recirculation,..). This tool is intended to be integrated in global simulation model of the CHP plant and the attached district heating network installed on the University campus in Liège. Doing so, the plant operation can be optimized with respect to economic as well as environmental and energetic aspects (3E approach) thus ensuring the sustainability of the approach.

See detailForcer l'avenir, alliances innovantes pour le développement durable - Écologie industrielle
Sartor, Kevin; Huysmans, Hélène; Corman, Marjorie

Conference given outside the academic context (2012)

En préparation au sommet Rio + 20, les étudiants du master en sciences de gestion à finalité en Management des entreprises sociales de l'Université de Liège organisent un colloque le 27 avril sur le thème des alliances innovantes pour le développement durable. Quatre pistes seront évoquées, soit: - Alliance producteurs- consommateurs - Ecologie industrielle - Emplois verts et inclusion sociale - Organisations et dispositifs supports Les ministres de l'Economie, Jean-Claude Marcourt, et du Développement Durable, Jean-Marc Nollet seront présents.

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See detailThe use of liquid biofuels in heating systems: a review
Makaire, Danielle; Sartor, Kevin; Ngendakumana, Philippe

Conference (2011, August)

European Union has set the 2020 strategy to increase the share of renewable energy use to 20% by 2020. Currently, most attention is focussed on the use of alternative fuels from biomass for energy purposes. These alternative fuels are called bioliquids. This paper reviews the current experimental works that have been performed on the combustion of vegetable oil, biodiesel and bioethanol in various heating combustion units. This review focuses on the feasibility of bioliquids use in heating systems as well as their “environmental friendly” potential.

See detailValidation théorique d’une Architecture d’injection Régénérative pour moteur thermique au Gaz Liquéfié (VARGAL) : Rapport semestriel n° 4, Rapport Final.
Sartor, Kevin; Ngendakumana, Philippe

Report (2011)

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See detailStudy of the feasibility of burning neat jatropha oil into a vaporizing burner for household applications
Makaire, Danielle; Fontaine, Jean-Marie; Sartor, Kevin; Ngendakumana, Philippe

in Biomass and Bioenergy (2011)

Charcoal is one of the major energy sources for household applications in urban areas of developing countries. It is often made from natural forest and accelerates forest depletion. The aim of this work was to evaluate the use of jatropha oil for combustion in vaporizing burners. This paper presents laboratory tests on a burner whose nominal output is 7.5kW. The burner had to be modified because of the high viscosity of jatropha oil and for cold start, as the oil flash point is much higher than fuel oil flash point. Pollutants emissions and thermal performances are analyzed for three firing rates. The burner meets EN1 standards at high firing rate. Unburned emissions are higher for middle and low firing rates.

See detailValidation théorique d’une Architecture d’injection Régénérative pour moteur thermique au Gaz Liquéfié (VARGAL) : Rapport semestriel n° 3
Sartor, Kevin; Ngendakumana, Philippe

Report (2010)

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See detailNatural Gas as an Alternative Fuel for Spark Ignition Engines
Sartor, Kevin; Ngendakumana, Philippe

Scientific conference (2010, May)

See detailValidation théorique d’une Architecture d’injection Régénérative pour moteur thermique au Gaz Liquéfié (VARGAL) : Rapport semestriel n°2
Sartor, Kevin; Ngendakumana, Philippe

Report (2010)

See detailValidation théorique d’une Architecture d’injection Régénérative pour moteur thermique au Gaz Liquéfié (VARGAL) : Rapport semestriel n° 1
Sartor, Kevin; Ngendakumana, Philippe

Report (2009)

See detailEtude du comportement d’échangeurs présentant en entrée un gaz chargé en humidité : Etude de la condensation dans un EGR air/eau glycolée
Sartor, Kevin; Ngendakumana, Philippe

Report (2008)

See detailEtude du comportement d’échangeurs présentant en entrée un gaz chargé en humidité : Etude de la condensation dans un RAS air/eau glycolée
Sartor, Kevin; Ngendakumana, Philippe

Report (2008)

See detailFeasibility study of the flameless oxidation in a semi-industrial boiler supplied by natural gas.
Sartor, Kevin

Master's dissertation (2008)