scholarly journals Investigating a Small Oil-Flooded Twin-Screw Expander for Waste-Heat Utilisation in Organic Rankine Cycle Systems

Energies ◽  
2017 ◽  
Vol 10 (7) ◽  
pp. 869 ◽  
Author(s):  
Alexander Nikolov ◽  
Andreas Brümmer
Keyword(s):  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Cycle Systems ◽  
Twin Screw

scholarly journals Comparison of Organic Rankine Cycle Systems under Varying Conditions Using Turbine and Twin-Screw Expanders

Energies ◽  
2016 ◽  
Vol 9 (8) ◽  
pp. 614 ◽  
Author(s):  
Matthew Read ◽  
Ian Smith ◽  
Nikola Stosic ◽  
Ahmed Kovacevic
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Cycle Systems ◽  
Twin Screw

3D CFD Analysis of a Twin Screw Expander With Different Real Gas Models for R245fa

2015 ◽  
Author(s):  
Iva Papes ◽  
Lazhar Abdelli ◽  
Joris Degroote ◽  
Jan Vierendeels
Keyword(s):  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Primary Energy ◽  
Ideal Gas ◽  
Production Costs ◽  
Working Fluid ◽  
Real Gas ◽  
Twin Screw ◽  
The Ideal

With the increasing importance of minimizing primary energy usage and complying with emission restrictions, a significant interest has been developed towards waste heat recovery from industrial processes. A large portion of this energy is available at low temperatures (350K–400K) but it can be relatively efficiently converted into mechanical power using an Organic Rankine Cycle (ORC). Twin screw expanders can be used as an alternative to turbines with their cheap production costs and well proven efficiencies. In this paper, 3D CFD simulations of a twin screw expander using R245fa as the working fluid are performed. Since the fluid properties show big deviations when using the ideal gas equation of state (EoS), the flow problem has been evaluated using different real gas models. Thermodynamic parameters for the ideal gas EoS, the cubic Aungier Redlich-Kwong EoS and the CoolProp fluid database (open source) were compared in a preliminary study. After that, the models have been included through user-defined functions (UDFs) in ANSYS Fluent and were tested on 3D CFD calculations of a twin screw expander and a simplified expansion model. Several performance indicators such as mass flow rates, pressure-volume diagrams and power output are used to compare different fluid models for R245fa. From the results of this study, it can be concluded that the ideal gas EoS shows big deviations going closer to the saturation vapor line and the deviation in power comparing to the Aungier Redlich-Kwong EoS is around 8%. Conversely, the Aungier Redlich-Kwong EoS and the CoolProp database present very similar results for this case.

Optimisation of Power Plant Operating on Waste Heat of Gas IC Engine Driven Power Generator

2016 ◽  
Author(s):  
Matthew G. Read ◽  
Ian K. Smith ◽  
Nikola Stosic
Keyword(s):  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Design Parameters ◽  
Valuable Insight ◽  
Wet Steam ◽  
Ic Engine ◽  
Cycle Systems ◽  
And Performance ◽  
System Configurations

This paper describes the results of computation analysis aimed at assessing the potential benefits of several thermodynamic cycles for the recovery of waste heat from gas IC engines. This is achieved by modelling the plant and expander processes which provides the general specification of the plant in terms of key design parameters. Simultaneously, the thermodynamic performance of each cycle is calculated in terms of flow rate, power and efficiency. Detailed component models allow a rigorous investigation of the design and performance of Organic Rankine Cycle and Wet steam Cycle systems for these applications where the energy from both the water jacket and exhaust gas can be utilised. A number of system configurations are considered including cycles with wet steam expansion and organic Rankine cycles with dry vapour expansion, and the benefits of a steam-ORC cascaded arrangement are investigated. Optimisation of the system configurations provides valuable insight into the performance and practical requirements of IC waste heat recovery systems.

Experimental comparison of organic fluids for low temperature ORC (organic Rankine cycle) systems for waste heat recovery applications

Energy ◽  
2016 ◽  
Vol 97 ◽  
pp. 460-469 ◽  
Author(s):  
Adriano Desideri ◽  
Sergei Gusev ◽  
Martijn van den Broek ◽  
Vincent Lemort ◽  
Sylvain Quoilin
Keyword(s):  
Low Temperature ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Experimental Comparison ◽  
Cycle Systems ◽  
Organic Fluids

scholarly journals 3D CFD Analysis of an Oil Injected Twin Screw Expander

2013 ◽  
Author(s):  
I. Papes ◽  
J. Degroote ◽  
J. Vierendeels
Keyword(s):  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Simulation Models ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Small Scale ◽  
Multiphase Model ◽  
Flow Process ◽  
Twin Screw ◽  
Oil Injection

Small scale Organic Rankine Cycle (ORC) systems have a big potential for waste heat recovery in the market. Due to the smaller volume flows inside these systems, non-conventional expansion technologies such as screw expanders become more interesting. Recent economic studies have shown the important role of screw machines in such cycles. However, in order to get a better understanding of the expansion behaviour in an ORC, appropriate simulation models of screw expanders are necessary. The flow inside an oil-injected twin screw expander is modeled in detail with 3D CFD (Computational Fluid Dynamics) calculations. These simulations are challenging because of the deforming domain and the narrow gaps between the screws or between a screw and the casing. The deforming mesh motion is handled by an in-house code which generates a block-structured grid with the help of the solutions of the Laplace problem. The oil-phase was modeled with an Eulerian multiphase model and the working fluid is treated compressible. The performance of the screw expander is strongly affected by the oil-injection which provides lubrication and a better sealing of the gaps. Therefore, the different types of leakages inside the screw expander are studied and monitored. As the result of the simulations, knowledge about the flow process and the losses inside the oil-injected screw expander is built up.

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