Next Article in Journal
A Distance-Dependent Chinese Restaurant Process Based Method for Event Detection on Social Media
Next Article in Special Issue
Temperature Distribution through a Nanofilm by Means of a Ballistic-Diffusive Approach
Previous Article in Journal
3-D Printable Polymer Pelletizer Chopper for Fused Granular Fabrication-Based Additive Manufacturing
Previous Article in Special Issue
The Thermodynamics of Internal Combustion Engines: Examples of Insights
Open AccessArticle

Thermogravitational Cycles: Theoretical Framework and Example of an Electric Thermogravitational Generator Based on Balloon Inflation/Deflation

1
Licence de Physique, 4 place Jussieu, UPMC Université Paris 6, 75005 Paris, France
2
LCPO, UMR 5629, ENSCBP 16 avenue Pey Berland, Univ. Bordeaux, 33607 Pessac, France
3
Laboratoire de Chimie des Polymères Organiques, UMR 5629, ENSCBP 16 avenue Pey Berland, CNRS, 33607 Pessac, France
4
Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
5
Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
6
Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
*
Author to whom correspondence should be addressed.
Inventions 2018, 3(4), 79; https://doi.org/10.3390/inventions3040079
Received: 26 October 2018 / Revised: 22 November 2018 / Accepted: 27 November 2018 / Published: 30 November 2018
(This article belongs to the Special Issue Thermodynamics in the 21st Century)
Several studies have involved a combination of heat and gravitational energy exchanges to create novel heat engines. A common theoretical framework is developed here to describe thermogravitational cycles which have the same efficiencies as the Carnot, Rankine, or Brayton cycles. Considering a working fluid enclosed in a balloon inside a column filled with a transporting fluid, a cycle is composed of four steps. Starting from the top of the column, the balloon goes down by gravity, receives heat from a hot source at the bottom, then rises and delivers heat to a cold source at the top. Unlike classic power cycles which need external work to operate the compressor, thermogravitational cycles can operate as a “pure power cycle” where no external work is needed to drive the cycle. To illustrate this concept, the prototype of a thermogravitational electrical generator is presented. It uses a hot source of average temperature near 57 °C and relies on the gravitational energy exchanges of an organic fluorinated fluid inside a balloon attached to a magnetic marble to produce an electromotive force of 50 mV peak to peak by the use of a linear alternator. This heat engine is well suited to be operated using renewable energy sources such as geothermal gradients or focused sunlight. View Full-Text
Keywords: thermogravitational cycle; thermogravitational electric generator; pure power cycle; Carnot; Rankine; and Brayton cycles; gravitational force; compression and expansion; waste heat; geothermal or solar energy harvesting thermogravitational cycle; thermogravitational electric generator; pure power cycle; Carnot; Rankine; and Brayton cycles; gravitational force; compression and expansion; waste heat; geothermal or solar energy harvesting
Show Figures

Figure 1

MDPI and ACS Style

Aouane, K.; Sandre, O.; Ford, I.J.; Elson, T.P.; Nightingale, C. Thermogravitational Cycles: Theoretical Framework and Example of an Electric Thermogravitational Generator Based on Balloon Inflation/Deflation. Inventions 2018, 3, 79.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop