Next Article in Journal
An Integrated Start-Up Method for Pumped Storage Units Based on a Novel Artificial Sheep Algorithm
Previous Article in Journal
A Novel Dual-Permanent-Magnet-Excited Machine with Flux Strengthening Effect for Low-Speed Large-Torque Applications
Article Menu
Issue 1 (January) cover image

Export Article

Open AccessConcept Paper
Energies 2018, 11(1), 154; https://doi.org/10.3390/en11010154

Isobaric Expansion Engines: New Opportunities in Energy Conversion for Heat Engines, Pumps and Compressors

1
Encontech B.V. ET/TE, P.O. Box 217, 7500 AE Enschede, The Netherlands
2
Chair of Fluid Process Engineering, Paderborn University, Pohlweg 55, 33098 Paderborn, Germany
3
Chair of Thermodynamics and Heat Engines, Gubkin Russian State University of Oil and Gas, Leninsky Prospekt 65, Moscow 119991, Russia
*
Author to whom correspondence should be addressed.
Received: 12 December 2017 / Revised: 31 December 2017 / Accepted: 4 January 2018 / Published: 8 January 2018
(This article belongs to the Section Energy Fundamentals and Conversion)
Full-Text   |   PDF [4315 KB, uploaded 10 January 2018]   |  

Abstract

Isobaric expansion (IE) engines are a very uncommon type of heat-to-mechanical-power converters, radically different from all well-known heat engines. Useful work is extracted during an isobaric expansion process, i.e., without a polytropic gas/vapour expansion accompanied by a pressure decrease typical of state-of-the-art piston engines, turbines, etc. This distinctive feature permits isobaric expansion machines to serve as very simple and inexpensive heat-driven pumps and compressors as well as heat-to-shaft-power converters with desired speed/torque. Commercial application of such machines, however, is scarce, mainly due to a low efficiency. This article aims to revive the long-known concept by proposing important modifications to make IE machines competitive and cost-effective alternatives to state-of-the-art heat conversion technologies. Experimental and theoretical results supporting the isobaric expansion technology are presented and promising potential applications, including emerging power generation methods, are discussed. It is shown that dense working fluids with high thermal expansion at high process temperature and low compressibility at low temperature make it possible to operate with reasonable thermal efficiencies at ultra-low heat source temperatures (70–100 °C). Regeneration/recuperation of heat can increase the efficiency notably and extend the area of application of these machines to higher heat source temperatures. For heat source temperatures of 200–600 °C, the efficiency of these machines can reach 20–50% thus making them a flexible, economical and energy efficient alternative to many today’s power generation technologies, first of all organic Rankine cycle (ORC). View Full-Text
Keywords: isobaric expansion; alternative engine; unconventional engine; low-grade heat; waste heat; hydraulic output; heat-driven pump; regenerator; ORC isobaric expansion; alternative engine; unconventional engine; low-grade heat; waste heat; hydraulic output; heat-driven pump; regenerator; ORC
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Glushenkov, M.; Kronberg, A.; Knoke, T.; Kenig, E.Y. Isobaric Expansion Engines: New Opportunities in Energy Conversion for Heat Engines, Pumps and Compressors. Energies 2018, 11, 154.

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.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Energies EISSN 1996-1073 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top