scholarly journals Design and Optimization of a Radial Inflow Turbine for Use with a Low Temperature ORC

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8526
Author(s):  
Richard Symes ◽  
Tchable-Nan Djaname ◽  
Michael Deligant ◽  
Emilie Sauret
Keyword(s):  
Fuel Cell ◽  
Low Temperature ◽  
High Efficiency ◽  
Waste Heat ◽  
Fluid Dynamic ◽  
Organic Rankine Cycle ◽  
Pem Fuel Cells ◽  
Small Scale ◽  
Heat Sources ◽  
Radial Inflow Turbine

This study aims to design and optimize an organic Rankine cycle (ORC) and radial inflow turbine to recover waste heat from a polymer exchange membrane (PEM) fuel cell. ORCs can take advantage of low-quality waste heat sources. Developments in this area have seen previously unusable, small waste heat sources become available for exploitation. Hydrogen PEM fuel cells operate at low temperatures (70 °C) and are in used in a range of applications, for example, as a balancing or backup power source in renewable hydrogen plants. The efficiency of an ORC is significantly affected by the source temperature and the efficiency of the expander. In this case, a radial inflow turbine was selected due to the high efficiency in ORCs with high density fluids. Small scale radial inflow turbines are of particular interest for improving the efficiency of small-scale low temperature cycles. Turbines generally have higher efficiency than positive displacement expanders, which are typically used. In this study, the turbine design from the mean-line analysis is also validated against the computational fluid dynamic (CFD) simulations conducted on the optimized machine. For the fuel cell investigated in this study, with a 5 kW electrical output, a potential additional 0.7 kW could be generated through the use of the ORC. The ORC’s output represents a possible 14% increase in performance over the fuel cell without waste heat recovery (WHR).

Design of Small-Scale Radial Inflow Turbine Integrated into Organic Rankine Cycle

2012 ◽  
Vol 524-527 ◽  
pp. 3907-3913
Author(s):  
Hui Wang ◽  
Xin Ling Ma ◽  
Xin Li Wei
Keyword(s):  
Low Temperature ◽  
Flow Field ◽  
Simple Structure ◽  
High Efficiency ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
3D Models ◽  
Small Scale ◽  
Radial Inflow Turbine

Organic Rankine Cycle (ORC) is dramatically suitable for low temperature waste-heat generation. The small-scale radial inflow turbine is introduced to integrate into the ORC characterized by simple structure, low parts count, high efficiency, especially getting high efficiency under the condition of smaller flow. This turbine is comprised of four main parts named by the volute, the nozzle (stator), the impeller (rotor), and the diffuser respectively. This paper introduces how to design and model the parts in detail, discusses modeling skills and shares experience. The structure of the volute and impeller is so complicated that parts are not easy to model. These 3D models can directly import to both ANSYS and FLUENT to analysis the flow field in order to achieve the optimize parameters.

scholarly journals REVIEW OF ORGANIC RANKINE CYCLE USED IN SMALL- SCALE APPLICATION

2020 ◽  
Vol 7 (1) ◽  
pp. 52-63
Author(s):  
Ali A. F. Al-Hamadani ◽  
Aya Haitham. A. Kareem
Keyword(s):  
Heat Exchanger ◽  
High Efficiency ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Small Scale ◽  
Heat Sources ◽  
Radial Turbine ◽  
Temperature Method ◽  
Energy From Waste

Organic Rankine cycle an alternative way of generating energy from waste heat, fuel and gases at low-temperature. Method (ORC) proved successful and high efficiency to reduce environmental pollution, fuel consumption and convert low to medium heat sources. The paper will be presenting a review investigation on the organic Rankine cycle(ORC), cycle Background, (ORC) configuration, and selecting of working fluids and experimental studied of expansion apparatuses, which are classified into two type volumetric type such as (expander of rotary vane, scroll, reciprocating piston expander and screw) velocity kind (for example axial and radial turbine). Heat exchanger and expander apparatuses are considered economically expensive parts in (ORC).

scholarly journals Organic Rankine-Cycle Turbine Power Plant Utilizing Low Temperature Heat Sources

1980 ◽  
Author(s):  
V. Maizza
Keyword(s):  
Power Plant ◽  
Low Temperature ◽  
High Efficiency ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Heat Sources ◽  
Operational Parameters ◽  
Working Fluids ◽  
Waste Energy

Utilizing and converting of existing low temperature and waste heat sources by the use of a high efficiency bottoming cycle is attractive and should be possible for many locations. This paper presents a theoretical study on possible combination of an organic Rankine-cycle turbine power plant with the heat pump supplied by waste energy sources. Energy requirements and system performances are analyzed using realistic design operating condition for a middle town. Some conversion systems employing working fluids other than water are being studied for the purpose of proposed application. Thermodynamic efficiencies, with respect to available resource, have been calculated by varying some system operating parameters at various reference temperature. With reference to proposed application equations and graphs are presented which interrelate the turbine operational parameters for some possible working fluids with computation results.

Recent Developments in Solar and Low-Temperature Heat Sources Assisted Power and Cooling Systems: A Design Perspective

2019 ◽  
Vol 142 (4) ◽  
Author(s):  
Md. Tareq Chowdhury ◽  
Esmail M. A. Mokheimer
Keyword(s):  
Low Temperature ◽  
Fossil Fuels ◽  
Fossil Fuel ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Heat Sources ◽  
Cooling Systems ◽  
Temperature Heat ◽  
Recent Developments

Abstract Even though the renewable technologies are getting a gradually increasing share of the energy industry, the momentum of its growth is far away from outweighing the dominance of fossil fuel. Due to the concern for ozone depletion, global warming, and many more environmental hazards caused by fossil fuels, it is essential to substitute the conventional energy sources with renewables. Since this replacement cannot be done overnight, the conventional energy technologies should be integrated with renewables to minimize the pace of adverse effects on fossil fuel–based industries in the meantime. This way, the industries can be more efficient by utilizing waste heat, which accounts for 50% of the total energy generated now. This review paper outlines the role of solar energy in the generation of power and cooling systems that are capable of utilizing low-temperature heat sources below 400 °C. The review is primarily concentrated on line-focused concentrated solar power (CSP)-assisted solar technologies to be integrated with organic Rankine cycle (ORC) and absorption cooling systems. Photovoltaic and similar multigeneration systems are also discussed in brief.

Optimization of Cycle and Expander Design of an Organic Rankine Cycle Unit Using Multi-Component Working Fluids

2016 ◽  
Author(s):  
Andrea Meroni ◽  
Jesper Graa Andreasen ◽  
Leonardo Pierobon ◽  
Fredrik Haglind
Keyword(s):  
Low Temperature ◽  
Power Systems ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Fluid Temperature ◽  
Heat Sources ◽  
Working Fluids ◽  
Turbine Performance ◽  
Temperature Heat

Organic Rankine cycle (ORC) power systems represent attractive solutions for power conversion from low temperature heat sources, and the use of these power systems is gaining increasing attention in the marine industry. This paper proposes the combined optimal design of cycle and expander for an organic Rankine cycle unit utilizing waste heat from low temperature heat sources. The study addresses a case where the minimum temperature of the heat source is constrained and a case where no constraint is imposed. The former case is the waste heat recovery from jacket cooling water of a marine diesel engine onboard a large ship, and the latter is representative of a low-temperature geothermal, solar or waste heat recovery application. Multi-component working fluids are investigated, as they allow improving the match between the temperature profiles in the heat exchangers and, consequently, reducing the irreversibility in the ORC system. This work considers mixtures of R245fa/pentane and propane/isobutane. The use of multi-component working fluids typically results in increased heat transfer areas and different expander designs compared to pure fluids. In order to properly account for turbine performance and design constraints in the cycle calculation, the thermodynamic cycle and the turbine are optimized simultaneously in the molar composition range of each mixture. Such novel optimization approach enables one to identify to which extent the cycle or the turbine behaviour influences the selection of the optimal solution. It also enables one to find the composition for which an optimal compromise between cycle and turbine performance is achieved. The optimal ORC unit employs pure R245fa and provides approximately 200 kW when the minimum hot fluid temperature is constrained. Conversely, the mixture R245fa/pentane (0.5/0.5) is selected and provides approximately 444 kW when the hot fluid temperature is not constrained to a lower value. In both cases, a compact and efficient turbine can be manufactured.

scholarly journals A Simple Method of Finding New Dry and Isentropic Working Fluids for Organic Rankine Cycle

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 480 ◽  
Author(s):  
Gábor Györke ◽  
Axel Groniewsky ◽  
Attila Imre
Keyword(s):  
Low Temperature ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Electricity Production ◽  
Working Fluid ◽  
Heat Sources ◽  
Simple Method ◽  
Working Fluids ◽  
Temperature Heat

One of the most crucial challenges of sustainable development is the use of low-temperature heat sources (60–200 °C), such as thermal solar, geothermal, biomass, or waste heat, for electricity production. Since conventional water-based thermodynamic cycles are not suitable in this temperature range or at least operate with very low efficiency, other working fluids need to be applied. Organic Rankine Cycle (ORC) uses organic working fluids, which results in higher thermal efficiency for low-temperature heat sources. Traditionally, new working fluids are found using a trial-and-error procedure through experience among chemically similar materials. This approach, however, carries a high risk of excluding the ideal working fluid. Therefore, a new method and a simple rule of thumb—based on a correlation related to molar isochoric specific heat capacity of saturated vapor states—were developed. With the application of this thumb rule, novel isentropic and dry working fluids can be found applicable for given low-temperature heat sources. Additionally, the importance of molar quantities—usually ignored by energy engineers—was demonstrated.

Analysis of a Combined Power and Ejector Refrigeration Cycle for Low Temperature Heat Sources

2009 ◽  
Author(s):  
Bin Zheng ◽  
Yiwu Weng
Keyword(s):  
Low Temperature ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Refrigeration Cycle ◽  
Heat Sources ◽  
Working Fluids ◽  
Temperature Heat ◽  
Cycle Efficiency

This paper presents a combined power and ejector refrigeration cycle for low temperature heat sources. The proposed cycle combines the organic Rankine cycle and the ejector refrigeration cycle. It can be used as an independent cycle powered by the low temperature sources, such as solar energy, geothermal energy, or as a bottom cycle of the conventional power plant for the recovery of low temperature waste heat. A program was developed to calculate the performance of the combined cycle. Several substances were selected as the working fluids including R113, R123, R245fa, R141b and R600. Simulation results show that R141b has the highest cycle efficiency, followed by R123, R113, R600 and then R245fa. While the working fluids are calculated by per unit, R600 can produce more power and refrigeration outputs due to the large latent heat. Simulations at different generating temperatures, evaporating temperatures and condensing temperatures were also discussed.

scholarly journals Design Method and Performance Prediction for Radial-Inflow Turbines of High-Temperature Mini-Organic Rankine Cycle Power Systems

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Carlo M. De Servi ◽  
Matteo Burigana ◽  
Matteo Pini ◽  
Piero Colonna
Keyword(s):  
Power Systems ◽  
Computational Fluid Dynamic ◽  
Dynamic Models ◽  
Waste Heat ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Loss Models ◽  
Radial Inflow Turbine

The realization of commercial mini organic Rankine cycle (ORC) power systems (tens of kW of power output) is currently pursued by means of various research and development activities. The application driving most of the efforts is the waste heat recovery from long-haul truck engines. Obtaining an efficient mini radial inflow turbine, arguably the most suitable type of expander for this application, is particularly challenging, given the small mass flow rate, and the occurrence of nonideal compressible fluid dynamic effects in the stator. Available design methods are currently based on guidelines and loss models developed mainly for turbochargers. The preliminary geometry is subsequently adapted by means of computational fluid-dynamic calculations with codes that are not validated in case of nonideal compressible flows of organic fluids. An experimental 10 kW mini-ORC radial inflow turbine will be realized and tested in the Propulsion and Power Laboratory of the Delft University of Technology, with the aim of providing measurement datasets for the validation of computational fluid dynamics (CFD) tools and the calibration of empirical loss models. The fluid dynamic design and characterization of this machine is reported here. Notably, the turbine is designed using a meanline model in which fluid-dynamic losses are estimated using semi-empirical correlations for conventional radial turbines. The resulting impeller geometry is then optimized using steady-state three-dimensional computational fluid dynamic models and surrogate-based optimization. Finally, a loss breakdown is performed and the results are compared against those obtained by three-dimensional unsteady fluid-dynamic calculations. The outcomes of the study indicate that the optimal layout of mini-ORC turbines significantly differs from that of radial-inflow turbines (RIT) utilized in more traditional applications, confirming the need for experimental campaigns to support the conception of new design practices.

Design and Flow Analysis of a Supersonic Small Scale ORC Turbine Stator With High Molecular Complexity Working Fluid

2014 ◽  
Author(s):  
Antti Uusitalo ◽  
Teemu Turunen-Saaresti ◽  
Alberto Guardone ◽  
Aki Grönman
Keyword(s):  
High Efficiency ◽  
Waste Heat ◽  
Flow Analysis ◽  
Organic Rankine Cycle ◽  
Working Fluid ◽  
Small Scale ◽  
Low Grade ◽  
Real Gas ◽  
Turbine Stator ◽  
Molecular Complexity

In small scale and low temperature waste heat recovery systems, Organic Rankine Cycle (ORC) technology can be identified as a promising solution in converting low-grade heat into electricity. The principle of ORC is based on a conventional Rankine process but an organic working fluid is adopted instead of steam. The use of high molecular complexity working fluids enables the design of high efficiency ORCs and are characterized by dry expansion and high pressure ratios over the turbine, as well as low speed of sound, which typically leads to highly supersonic flows in the ORC turbine stator. In order to design supersonic ORC turbines, the geometry of the turbine stator has to be based on design methods that accurately take into account the real gas effects of the working fluid during the expansion. In this study, a highly supersonic small scale ORC turbine stator using siloxane MDM as working fluid, is studied. The accurate real gas model was implemented in a CFD-flow solver in order to predict the flow field in the stator in design and in off-design conditions. The results of this study gives valuable information on realising small capacity ORC turbomachinery, characterized by highly supersonic stators, and on the off-design performance of supersonic radial turbine stator that has not been documented or discussed in the previous studies.

Computational Analysis of the Methane Steam Reforming Process With Low-Temperature Waste Heat Source

2016 ◽  
Author(s):  
Gahui Shin ◽  
Jinwon Yun ◽  
Sangseok Yu
Keyword(s):  
Fuel Cell ◽  
Low Temperature ◽  
Steam Reforming ◽  
High Efficiency ◽  
Waste Heat ◽  
Cell System ◽  
Methane Steam Reforming ◽  
Maximum Temperature ◽  
Fuel Cell System ◽  
Methane Steam

When the high temperature stationary fuel cell system is designed with external reformer, typical approach to improve efficiency of system is to employ catalytic burner with fuel lean anode-off gas for methane steam reformer. Recently, there have been many studies on the hybrid fuel cell system using anode-off gas to produce additional power. In those hybrid systems, maximum temperature of heat duty for the reformer is significantly reduced. Optimization of heat management is very important for these low temperature reformers. In this study, we carried out an analytic study of the methane steam reforming process with heat duty of non-reactive, low temperature gases. It is found out that the temperature uniformity of inlet gases is crucial for high efficiency. Additionally, the reformer geometry such as heat transfer area and the aspect ratio are meaningful parameters which can severely affect the methane conversion rate under given conditions.

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