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Concept

Pompe à chaleur

Résumé

Une pompe à chaleur (PAC), aussi appelée thermopompe en français canadien, est un dispositif permettant de transférer de l'énergie thermique (anciennement « calories ») d'un milieu à basse température (source froide) vers un milieu à haute température (source chaude). Ce dispositif permet donc d'inverser le sens naturel du transfert spontané de l'énergie thermique. Selon le sens de fonctionnement du dispositif de pompage, une pompe à chaleur peut être considérée comme un système de chauffage, si l'on souhaite augmenter la température de la source chaude, ou de réfrigération, si l'on souhaite abaisser la température de la source froide. Pour la production de froid, le procédé est à la base de la quasi totalité des climatiseurs et réfrigérateurs. Pour la production de chaleur, le procédé diffère du chauffage classique, dans lequel un corps est chauffé (par effet Joule, par combustion, ou par tout autre procédé). Lorsque le dispositif de pompage fournit simultanément chauffage et réfr

Source officielle

https://fr.wikipedia.org/wiki/Pompe_%C3%A0_chaleur

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Methods for the rational use and conversion of energy in industrial processes : how to analyse the energy usage, calculate the heat recovery by pinch analysis, define heat exchanger network, integrate heat pumps and cogeneration units and realise exergy analysis of energy conversion systems.

Introduction aux principes de la thermodynamique, propriétés thermodynamiques de la matière et à leur calcul. Les étudiants maîtriseront les concepts de conservation (chaleur, masse, quantité de mouvement) et appliqueront ces concepts au cycles thermodynamiques et systèmes de conversion d'énergie.

This course aims at studying thermal power cycles, heat pumping technologies, and equipment.

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Séances de cours associées (251)

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Data-based identification of a parametric heat pump model

Franca Schmid

At the LENI a heat pump model has been developed, which aims to simulate a single state compression heat pump in both steady state and transient regime. For gaining the experimental data and for the simulation the same set of input data is used. The goal is to approximate the output values of the model ym to the ones measured in the experiments. Therefore a certain number of parameters need to be defined in order of obtaining the highest accuracy possible. At the beginning these different parameters γ need to be found and a criterion needs to be appointed which can be used to judge the accuracy of the model. The first approach to the identification is to only work with the steady states. This includes to select steady values out of a data sheet and to change the model so that only steady states are computed. As soon as the model is successfully running for the steady states an optimizer needs to be chosen to finally output the best values of parameters. Subsequently the improvement of the output vector ym needs to be checked. As during the examination some computational problems have been revealed, which interfered with the optimization, various influences on the heat pump model were investigated. It was tried to find the reason for numerical problems and to eliminate those in order to finally be able to optimise the parameters. To identify the model in the transient regime the model needs to be linearised at a typical operation condition. The new chosen criterion must also take into account the transient regimes and the optimality of the solution has to be proved. The numerical problems which exist for the steady state also influence the transient regime. As the emphasis was therefore put on finding the origin of the instabilities, the identification of the transient regime was only briefly worked on.

2010

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Heat Pump Integration Into Urban Energy Systems

Leonardo Gonçalo Melo

Groupe E a promoter of district heating networks was confronted with the possibility of building a network of this nature in the municipality of La Tour-de-Peilz. The munici- pality imposed a situation where the lake water should be used for heat pumping. By mapping the heat demand with the help of Geographical Information System (GIS) tools and a database manager it was possible to simulate the thermal behavior of the build- ings within the bounds of the municipality. To carry on an analysis on the performance of several heat supply scenarios, industrial process integration techniques were used to verify the performance of diﬀerent technologies in the basis of environomic indicators. The base case in the municipality being a traditional boiler, was then compared on the basis of these indicators. It was found that for the buildings existing in the municipality, the best choice is to install high temperature heat pumps that do not perform as well in terms of exergy eﬃciency as low temperature heat pumps but they can create the bridge between the goal of the promoter and the pollution mitigation. With this solution, re- ductions of 98& in C O2 equivalent green house gases is achieved and an increase of 64% in the exergy eﬃciency of the chain of enerdy conversion.

2011

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EPFL's District Heating Heat Pump - Performance Analysis for DIfferent Working Fluids

Sylvain Clément

The present case study is multi-criteria performance analysis of EPFL’s heat pump for different working fluids. The heat pump is based on a 2-stage vapour compression cycle which is modelled using the software Belsim VALI for 7 low-GWP refrigerants. The simulation of the heat pump over different typical periods allowed to estimate the yearly mean COP of the heat pump. R-600a, R-600 and R-717 are the refrigerants showing the higher thermal efficiencies (COP = 5.5-5.7) and thereby also the higher environmental and economical performances. According to the TEWI indicator, the leakages of low-GWP refrigerants are negligible compared to the CO2-eq. emissions from the electricity generation. The decrease in the isentropic efficiency when the heat pump does not work at its maximum capacity strongly affect the COP. Therefore it is recommended to implement a heat storage system to increase the number of operating hours without isentropic efficiency decrease.

2021

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