scholarly journals Effects of the Working Fluid Charge in Organic Rankine Cycle Power Systems: Numerical and Experimental Analyses

2018 ◽  
Author(s):  
Davide Ziviani ◽  
Rémi Dickes ◽  
Vincent Lemort ◽  
James E. Braun ◽  
Eckhard A. Groll
Keyword(s):  
Power Systems ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Experimental Analyses

scholarly journals Organic Rankine Cycle Power Systems: From the Concept to Current Technology, Applications, and an Outlook to the Future

2015 ◽  
Vol 137 (10) ◽  
Author(s):  
Piero Colonna ◽  
Emiliano Casati ◽  
Carsten Trapp ◽  
Tiemo Mathijssen ◽  
Jaakko Larjola ◽  
...  
Keyword(s):  
Power Systems ◽  
Research And Development ◽  
Thermal Energy ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Biomass Combustion ◽  
Main Stream ◽  
Advantages And Disadvantages ◽  
The Many

The cumulative global capacity of organic Rankine cycle (ORC) power systems for the conversion of renewable and waste thermal energy is undergoing a rapid growth and is estimated to be approx. 2000 MWe considering only installations that went into operation after 1995. The potential for the conversion of the thermal power coming from liquid-dominated geothermal reservoirs, waste heat from primary engines or industrial processes, biomass combustion, and concentrated solar radiation into electricity is arguably enormous. ORC technology is possibly the most flexible in terms of capacity and temperature level and is currently often the only applicable technology for the conversion of external thermal energy sources. In addition, ORC power systems are suitable for the cogeneration of heating and/or cooling, another advantage in the framework of distributed power generation. Related research and development is therefore very lively. These considerations motivated the effort documented in this article, aimed at providing consistent information about the evolution, state, and future of this power conversion technology. First, basic theoretical elements on the thermodynamic cycle, working fluid, and design aspects are illustrated, together with an evaluation of the advantages and disadvantages in comparison to competing technologies. An overview of the long history of the development of ORC power systems follows, in order to place the more recent evolution into perspective. Then, a compendium of the many aspects of the state of the art is illustrated: the solutions currently adopted in commercial plants and the main-stream applications, including information about exemplary installations. A classification and terminology for ORC power plants are proposed. An outlook on the many research and development activities is provided, whereby information on new high-impact applications, such as automotive heat recovery is included. Possible directions of future developments are highlighted, ranging from efforts targeting volume-produced stationary and mobile mini-ORC systems with a power output of few kWe, up to large MWe base-load ORC plants.

The Application of Rotary Vane Expanders in Organic Rankine Cycle Systems—Thermodynamic Description and Experimental Results

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Zbigniew Gnutek ◽  
Piotr Kolasiński
Keyword(s):  
Power Systems ◽  
Thermodynamic Description ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Test Stand ◽  
Working Fluid ◽  
Cycle Systems ◽  
Set Up ◽  
Domestic Power ◽  
Small Capacity

Small (10–100 kW) and micro (0.5–10 kW) Organic Rankine Cycle (ORC) power systems are nowadays considered for local and domestic power generation. Especially interesting are micropower applications for heat recovery from dispersed low potential (85–150 °C) waste and renewable heat sources. Designing and implementing an ORC system dedicated to energy recovery from such a source is difficult. A proper working fluid must be selected together with a suitable expander. Volumetric machines can be adopted as a turbine alternative in small-capacity applications under development, like, e.g., domestic cogeneration. Scroll and screw expanders are a common choice. However, scroll and screw expanders are complicated and expensive. Vane expanders are mechanically simple, commercially available and cheap. This paper documents a study providing the preliminary analysis of the possibility of employing vane-expanders in mini-ORC systems. The main objective of this research was therefore a comprehensive analysis of the use of a vane expander for continuous operation with a low-boiling working fluid. A test-stand was designed and set up starting from system models based on thermodynamic analysis. Then, a series of experiments was performed using the test-stand. Results of these experiments are presented here, together with a model of multivane expanders and a thermodynamic-based method to select the working fluid. The analysis presented in this paper indicates that multivane expanders are a cheap and mechanically simple alternative to other expansion devices proposed for small-capacity ORC systems.

High-Efficiency Solar Dynamic Space Power Generation System

1991 ◽  
Vol 113 (3) ◽  
pp. 131-137 ◽  
Author(s):  
Aristide Massardo
Keyword(s):  
Power Generation ◽  
Power Systems ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Working Fluid ◽  
Brayton Cycle ◽  
Generation System ◽  
Dynamic Power ◽  
Power Generation System

Space power technologies have undergone significant advances over the past few years, and great emphasis is being placed on the development of dynamic power systems at this time. A design study has been conducted to evaluate the applicability of a combined cycle concept—closed Brayton cycle and organic Rankine cycle coupling—for solar dynamic space power generation systems. In the concept presented here (solar dynamic combined cycle), the waste heat rejected by the closed Brayton cycle working fluid is utilized to heat the organic working fluid of an organic Rankine cycle system. This allows the solar dynamic combined cycle efficiency to be increased compared to the efficiencies of two subsystems (closed Brayton cycle and organic fluid cycle). Also, for small-size space power systems (up to 50 kW), the efficiency of the solar dynamic combined cycle can be comparable with Stirling engine performance. The closed Brayton cycle and organic Rankine cycle designs are based on a great deal of maturity assessed in much previous work on terrestrial and solar dynamic power systems. This is not yet true for the Stirling cycles. The purpose of this paper is to analyze the performance of the new space power generation system (solar dynamic combined cycle). The significant benefits of the solar dynamic combined cycle concept such as efficiency increase, mass reduction, specific area—collector and radiator—reduction, are presented and discussed for a low earth orbit space station application.

scholarly journals Heat Exchanger Sizing for Organic Rankine Cycle

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3615 ◽  
Author(s):  
James Bull ◽  
James M. Buick ◽  
Jovana Radulovic
Keyword(s):  
Heat Exchanger ◽  
Power Systems ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Working Fluid ◽  
Two Phase ◽  
Operational Conditions ◽  
Shell And Tube

Approximately 45% of power generated by conventional power systems is wasted due to power conversion process limitations. Waste heat recovery can be achieved in an Organic Rankine Cycle (ORC) by converting low temperature waste heat into useful energy, at relatively low-pressure operating conditions. The ORC system considered in this study utilises R-1234yf as the working fluid; the work output and thermal efficiency were evaluated for several operational pressures. Plate and shell and tube heat exchangers were analysed for the three sections: preheater, evaporator and superheater for the hot side; and precooler and condenser for the cold side. Each heat exchanger section was sized using the appropriate correlation equations for single-phase and two-phase fluid models. The overall heat exchanger size was evaluated for optimal operational conditions. It was found that the plate heat exchanger out-performed the shell and tube in regard to the overall heat transfer coefficient and area.

scholarly journals Integrated working fluid-thermodynamic cycle design of organic Rankine cycle power systems for waste heat recovery

2017 ◽  
Vol 203 ◽  
pp. 442-453 ◽  
Author(s):  
Stefano Cignitti ◽  
Jesper G. Andreasen ◽  
Fredrik Haglind ◽  
John M. Woodley ◽  
Jens Abildskov
Keyword(s):  
Power Systems ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Thermodynamic Cycle ◽  
Rankine Cycle ◽  
Working Fluid

Model, simulation and experiments for a Buoyancy Organic Rankine Cycle

2020 ◽  
Vol 92 (1) ◽  
pp. 10906
Author(s):  
Jeroen Schoenmaker ◽  
Pâmella Gonçalves Martins ◽  
Guilherme Corsi Miranda da Silva ◽  
Julio Carlos Teixeira
Keyword(s):  
Model Simulation ◽  
Organic Rankine Cycle ◽  
Thermodynamic Cycle ◽  
Rankine Cycle ◽  
Test Body ◽  
Working Fluid ◽  
Proof Of Concept ◽  
Energy Scenario ◽  
New Type ◽  
Fluid Reservoir

Organic Rankine Cycle (ORC) systems are increasingly gaining relevance in the renewable and sustainable energy scenario. Recently our research group published a manuscript identifying a new type of thermodynamic cycle entitled Buoyancy Organic Rankine Cycle (BORC) [J. Schoenmaker, J.F.Q. Rey, K.R. Pirota, Renew. Energy 36, 999 (2011)]. In this work we present two main contributions. First, we propose a refined thermodynamic model for BORC systems accounting for the specific heat of the working fluid. Considering the refined model, the efficiencies for Pentane and Dichloromethane at temperatures up to 100 °C were estimated to be 17.2%. Second, we show a proof of concept BORC system using a 3 m tall, 0.062 m diameter polycarbonate tube as a column-fluid reservoir. We used water as a column fluid. The thermal stability and uniformity throughout the tube has been carefully simulated and verified experimentally. After the thermal parameters of the water column have been fully characterized, we developed a test body to allow an adequate assessment of the BORC-system's efficiency. We obtained 0.84% efficiency for 43.8 °C working temperature. This corresponds to 35% of the Carnot efficiency calculated for the same temperature difference. Limitations of the model and the apparatus are put into perspective, pointing directions for further developments of BORC systems.

scholarly journals Component-Oriented Modeling of a Micro-Scale Organic Rankine Cycle System for Waste Heat Recovery Applications

2021 ◽  
Vol 11 (5) ◽  
pp. 1984
Author(s):  
Ramin Moradi ◽  
Emanuele Habib ◽  
Enrico Bocci ◽  
Luca Cioccolanti
Keyword(s):  
Electric Power ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Working Fluid ◽  
Pump Efficiency ◽  
Micro Scale

Organic Rankine cycle (ORC) systems are some of the most suitable technologies to produce electricity from low-temperature waste heat. In this study, a non-regenerative, micro-scale ORC system was tested in off-design conditions using R134a as the working fluid. The experimental data were then used to tune the semi-empirical models of the main components of the system. Eventually, the models were used in a component-oriented system solver to map the system electric performance at varying operating conditions. The analysis highlighted the non-negligible impact of the plunger pump on the system performance Indeed, the experimental results showed that the low pump efficiency in the investigated operating range can lead to negative net electric power in some working conditions. For most data points, the expander and the pump isentropic efficiencies are found in the approximate ranges of 35% to 55% and 17% to 34%, respectively. Furthermore, the maximum net electric power was about 200 W with a net electric efficiency of about 1.2%, thus also stressing the importance of a proper selection of the pump for waste heat recovery applications.

scholarly journals Organic Rankine cycle for turboprop engine application

2021 ◽  
pp. 1-21
Author(s):  
G.E. Pateropoulos ◽  
T.G. Efstathiadis ◽  
A.I. Kalfas
Keyword(s):  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Weight Ratio ◽  
Rankine Cycle ◽  
Aircraft Engine ◽  
Working Fluid ◽  
Engine Fuel ◽  
Exhaust Gases ◽  
Waste Heat Recovery System ◽  
Turboprop Engine

ABSTRACT The potential to recover waste heat from the exhaust gases of a turboprop engine and produce useful work through an Organic Rankine Cycle (ORC) is investigated. A thermodynamic analysis of the engine’s Brayton cycle is derived to determine the heat source available for exploitation. The aim is to use the aircraft engine fuel as the working fluid of the organic Rankine cycle in order to reduce the extra weight of the waste heat recovery system and keep the thrust-to-weight ratio as high as possible. A surrogate fuel with thermophysical properties similar to aviation gas turbine fuel is used for the ORC simulation. The evaporator design as well as the weight minimisation and safety of the suggested application are the most crucial aspects determining the feasibility of the proposed concept. The results show that there is potential in the exhaust gases to produce up to 50kW of power, corresponding to a 10.1% improvement of the overall thermal efficiency of the engine.

Theoretical and experimental investigation of an organic Rankine cycle for a waste heat recovery system

2009 ◽  
Vol 223 (5) ◽  
pp. 523-533 ◽  
Author(s):  
W Gu ◽  
Y Weng ◽  
Y Wang ◽  
B Zheng
Keyword(s):  
Heat Source ◽  
Entropy Generation ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Entropy Generation Rate ◽  
Working Fluid ◽  
Total Entropy ◽  
Waste Heat Recovery System ◽  
Cycle Efficiency

This article describes and evaluates an organic Rankine cycle (ORC) for a waste heat recovery system by both theoretical and experimental studies. Theoretical analysis of several working fluids shows that cycle efficiency is very sensitive to evaporating pressure, but insensitive to expander inlet temperature. Second law analysis was carried out using R600a as a working fluid and a flow of hot air as a heat source, which is not isothermal, along the evaporator. The result discloses that the evaporator's internal and external entropy generation is the main source of total entropy generation. The effect of the heat source temperature, evaporating pressure, and evaporator size on the entropy generation rate is also presented. The obtained useful power is directly linked to the total entropy generation rate according to the Gouy—Stodola theorem. The ORC testing system was established and operated using R600a as a working fluid and hot water as a heat source. The maximum cycle efficiency of the testing system is 5.2 per cent, and the testing result also proves that cycle efficiency is insensitive to heat source temperature, but sensitive to evaporating pressure. The entropy result also shows that internal and external entropy of the evaporator is the main source of total entropy generation.

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