Dynamic modelling of the expansion cylinder of an open Joule cycle Ericsson engine: A bond graph approach. (1st May 2016)

• Record Type: Journal Article
• Authors: Creyx, M.; Delacourt, E.; Morin, C.; Desmet, B.
• Is Part Of: Energy. Volume 102(2016)
• Page Start: 31
• Page End: 43
• Publication Date: 2016-05-01
• Subjects: Ericsson engine -- Dynamic model -- Bond graphs -- Cogeneration -- Hot air engines; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2016.01.106
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: A dynamic model using the bond graph formalism of the expansion cylinder of an open Joule cycle Ericsson engine intended for a biomass-fuelled micro-CHP system is presented. Dynamic phenomena, such as the thermodynamic evolution of air, the instantaneous air mass flow rates linked to pressure drops crossing the valves, the heat transferred through the expansion cylinder wall and the mechanical friction losses, are included in the model. The influence on the Ericsson engine performances of the main operating conditions (intake air pressure and temperature, timing of intake and exhaust valve closing, rotational speed, mechanical friction losses and heat transfer at expansion cylinder wall) is studied. The operating conditions maximizing the performances of the Ericsson engine used in the a biomass-fuelled micro-CHP unit are an intake air pressure between 6 and 8 bar, a maximized intake air temperature, an adjustment of the intake and exhaust valve closing corresponding to an expansion cycle close to the theoretical Joule cycle, a rotational speed close to 800 rpm. The heat transfer at the expansion cylinder wall reduces the engine performances. Highlights: A bond graph dynamic model of the Ericsson engine expansion cylinder is presented. Dynamic aspects are modelled: pressure drops, friction losses, wall heat transfer. Influent factors and phenomena on the engine performances are investigated. Expansion cycles close to the theoretical Joule cycle maximize the performances. The heat transfer at the expansion chamber wall reduces the performances.