Performance evaluation of an Organic Rankine Cycle (ORC) for power applications from low grade heat sources

Abstract The Organic Rankine Cycle (ORC) allows the conversion of low-grade heat sources into electricity. Although this technology is not new, the increase in energy demand and the need to reduce CO2 emissions create new opportunities to harvest low grade heat sources such as waste heat. Radial turbines have a simple construction, they are robust and they are not very sensitive to geometry inaccuracies. Most of the radial inflow turbines used for ORC application feature a vaned nozzle ensuring the appropriate distribution angle at the rotor inlet. In this work, no nozzle is considered but only the vaneless gap (distributor). This configuration, without any vaned nozzle, is supposed to be more flexible under varying operating conditions with respect to fixed vanes and to maintain a good efficiency at off-design. This paper presents a performance analysis carried out by means of two approaches: a combination of meanline loss models enhanced with real gas fluid properties and 3D CFD computations, taking into account the entire turbomachine including the scroll housing, the vaneless gap, the turbine wheel and the axial discharge pipe. A detailed analysis of the flow field through the turbomachine is carried out, both under design and off design conditions, with a particular focus on the entropy field in order to evaluate the loss distribution between the scroll housing, the vaneless gap and the turbine wheel.

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Cost Effective Small Scale ORC Systems for Power Recovery From Low Grade Heat Sources

Advanced Energy Systems ◽

10.1115/imece2006-14284 ◽

2006 ◽

Cited By ~ 20

Author(s):

H. Leibowitz ◽

I. K. Smith ◽

N. Stosic

Keyword(s):

Organic Rankine Cycle ◽

Cost Effective ◽

Rankine Cycle ◽

Small Scale ◽

Low Grade ◽

Full Potential ◽

Heat Sources ◽

Capacity Cost ◽

Power Recovery ◽

Low Grade Heat

The growing need to recover power from low grade heat sources, has led to a review of the possibilities for producing systems for cost effective power production at outputs as little as 20-50kWe. It is shown that by utilizing the full potential of screw expanders instead of turbines, it is possible to produce Organic Rankine Cycle (ORC) systems at these outputs, which can be installed for a cost in the range of $1500 to $2000 /kWe of net output. This low capacity cost combined with the ORC's fuel-free specification results in a very favorable value proposition.

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Parametric study and performance evaluation of an organic Rankine cycle (ORC) system using low-grade heat at temperatures below 80 °C

Applied Energy ◽

10.1016/j.apenergy.2016.12.026 ◽

2017 ◽

Vol 189 ◽

pp. 55-65 ◽

Cited By ~ 32

Author(s):

Dong Kyu Kim ◽

Ji Sung Lee ◽

Jinwoo Kim ◽

Mo Se Kim ◽

Min Soo Kim

Keyword(s):

Performance Evaluation ◽

Parametric Study ◽

Organic Rankine Cycle ◽

Rankine Cycle ◽

Low Grade ◽

And Performance ◽

Low Grade Heat

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Experimental characterization of an ORC (organic Rankine cycle) for power and CHP (combined heat and power) applications from low grade heat sources

Energy ◽

10.1016/j.energy.2015.01.037 ◽

2015 ◽

Vol 82 ◽

pp. 269-276 ◽

Cited By ~ 33

Author(s):

Bernardo Peris ◽

Joaquín Navarro-Esbrí ◽

Francisco Molés ◽

Manuel González ◽

Adrián Mota-Babiloni

Keyword(s):

Organic Rankine Cycle ◽

Rankine Cycle ◽

Combined Heat And Power ◽

Low Grade ◽

Heat Sources ◽

Experimental Characterization ◽

Low Grade Heat

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Thermodynamic investigation of organic Rankine cycle energy recovery system and recent studies

Thermal Science ◽

10.2298/tsci170720103b ◽

2018 ◽

Vol 22 (6 Part A) ◽

pp. 2679-2690 ◽

Cited By ~ 1

Author(s):

Ozlem Boydak ◽

Ismail Ekmekci ◽

Mustafa Yilmaz ◽

Hasan Koten

Keyword(s):

Phase Change ◽

Low Temperatures ◽

Organic Rankine Cycle ◽

Rankine Cycle ◽

Energy Resources ◽

Working Fluid ◽

Low Grade ◽

Heat Sources ◽

Water Steam ◽

Low Grade Heat

Recently, new environment-friendly energy conversion technologies are required for using energy resources valid to power generation. Accordingly, low-grade heat sources as solar heat, geothermal energy, and waste heat, which have available temperatures ranging between 60 and 200?C, are supposed as applicants for recent new generation energy resources. As an alternative energy source, such low-grade heat sources usage generating electricity with the help of power turbine cycles was examined through this study. Such systems have existing technologies applicable at low temperatures and a compact structure at low cost, however, these systems have a low thermal efficiency of the Rankine cycles operated at low temperatures. An organic Rankine cycle is alike to a conventional steam power plant, except the working fluid, which is an organic, high molecular mass fluid with a liquid-vapor phase change, or boiling point, at a lower temperature than the water-steam phase change. The efficiency of an organic Rankine cycle is about between 10% and 20%, depending on temperature levels and availability of a valid fluid.

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