Submit to Energies Review for Energies Propose a Special Issue

Journal Browser

► Journal Browser

Organic Rankine Cycle (ORC)

Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Energies (ISSN 1996-1073).

Deadline for manuscript submissions: closed (31 January 2015) | Viewed by 127851

Share This Special Issue

Special Issue Editor

Prof. Dr. Roberto Capata

E-Mail Website1 Website2
Guest Editor

Department of Mechanical and Aerospace Engineering, University of Roma “Sapienza”, 00185 Roma, Italy
Interests: UMGT; hybrid vehicles and systems; machinery design; energy systems; ORC; heat exchangers; diagnostics; turbomachinery; volumetric machinery; biomedical machinery application
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

In recent years, research into small and medium sized producers of energy has focused on traditional and “old” applications like plants based on the Rankine cycle whose innovative idea is linked to the type of fluid used, namely, organic fluids.

The ORC (Organic Rankine Cycle) uses organic fluids other than water, such as hydrocarbons, HCFCS, polysiloxanes, from high molecular weight and low temperature phase change, to produce energy from heat at medium-low temperatures. In order to optimize the performance of the thermodynamic cycle, the choice of fluid has to be made according to the temperature of the heat source.

Such plants are often coupled with solar panels, heat sources based on geothermal energy, biomass and heat recovery from industrial processes. Moreover, they are often used for co-generation, where thermal energy is available in the form of hot water at a temperature of 60–90 °C.

Regarding plant costs, the total cost of a plant, including boiler, shroud, links, etc., is between 3500 and 6400 €/kW installed, while the cost of a turbo generator can be estimated at only around 900–1600 €/kW when installed.

In addition, lately, given the recent focus on energy saving and the use of new sources of energy, such as renewable energy, a renewed interest in the topic has been noted.

This has convinced the Energies Editor and Guest Editor to promote a special Issue on the topic that can be of interest to research into this technology, which will be one of the main feasible solutions to short, medium and long-term energy systems optimization and for waste heat recovery technology.

Dr. Roberto Capata
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

energy management and energy recovery
orc plant analysis and economical evaluation
orc low enthalpy energy recovery
operating fluids
components design
orc innovative plant

Published Papers (14 papers)

Download All Papers

Research

Jump to: Review

5539 KiB

Open AccessArticle

Part-Load Performance Prediction and Operation Strategy Design of Organic Rankine Cycles with a Medium Cycle Used for Recovering Waste Heat from Gaseous Fuel Engines

by Xuan Wang, Hua Tian and Gequn Shu

Energies 2016, 9(7), 527; https://doi.org/10.3390/en9070527 - 11 Jul 2016

Cited by 25 | Viewed by 6920

Abstract

The Organic Rankine Cycle (ORC) is regarded as a suitable way to recover waste heat from gaseous fuel internal combustion engines. As waste heat recovery systems (WHRS) have always been designed based on rated working conditions, while engines often work under part-load conditions, it is quite significant to analyze the part-load performance and corresponding operation strategy of ORC systems. This paper presents a dynamic model of ORC with a medium cycle used for a large gaseous fuel engine and analyzes the effect of adjustable parameters on the system performance, giving effective control directions under various conditions. The results indicate that the intermediary fluid mass flow rate has nearly no effect on the output power and thermal efficiency of the ORC, while the mass flow rate of working fluid has a great effect on them. In order to get a better system performance under different working conditions, the system should be operated with the working fluid mass flow rate as large as possible, but with a slight degree of superheating. Then, with the control of constant superheat degree at the end of the heating process, the performance of the combined system that consists of ORC and the engine at steady state under seven typical working conditions is also analyzed. The results indicate that the energy-saving effect of WHRS becomes worse and worse as the working condition decreases. Especially at 40% working condition the WHRS nearly has no energy-saving effect anymore. Full article

(This article belongs to the Special Issue Organic Rankine Cycle (ORC))

► Show Figures

Figure 1

567 KiB

Open AccessArticle

Calculation of Efficiencies of a Ship Power Plant Operating with Waste Heat Recovery through Combined Heat and Power Production

by Mirko Grljušić, Vladimir Medica and Gojmir Radica

Energies 2015, 8(5), 4273-4299; https://doi.org/10.3390/en8054273 - 12 May 2015

Cited by 35 | Viewed by 9665

Abstract

The aim of this research was to investigate the possibility of a combined heat & power (CHP) plant, using the waste heat from a Suezmax-size oil tanker’s main engine, to meet all heating and electricity requirements during navigation. After considering various configurations, a standard propulsion engine operating at maximum efficiency, combined with a supercritical Organic Rankine cycle (ORC) system, was selected to supply the auxiliary power, using R245fa or R123 as the working fluid. The system analysis showed that such a plant can meet all heat and electrical power requirements at full load, with the need to burn only a small amount of supplementary fuel in a heat recovery steam generator (HRSG) when the main engine operates at part load. Therefore, it is possible to increase the overall thermal efficiency of the ship’s power plant by more than 5% when the main engine operates at 65% or more of its specified maximum continuous rating (SMCR). Full article

(This article belongs to the Special Issue Organic Rankine Cycle (ORC))

► Show Figures

Figure 1

2532 KiB

Open AccessArticle

The Influence of the Heat Source Temperature on the Multivane Expander Output Power in an Organic Rankine Cycle (ORC) System

by Piotr Kolasiński

Energies 2015, 8(5), 3351-3369; https://doi.org/10.3390/en8053351 - 24 Apr 2015

Cited by 37 | Viewed by 6692

Abstract

Organic Rankine Cycle (ORC) power systems are nowadays an option for local and domestic cogeneration of heat and electric power. Very interesting are micropower systems for heat recovery from low potential (40–90 °C) waste and renewable heat sources. Designing an ORC system dedicated to heat recovery from such a source is very difficult. Most important problems are connected with the selection of a suitable expander. Volumetric machines, such as scroll and screw expanders, are adopted as turbine alternative in small-power ORC systems. However, these machines are complicated and expensive. Vane expanders on the other hand are simple and cheap. This paper presents a theoretical and experimental analysis of the operation of a micro-ORC rotary vane expander under variable heat source temperature conditions. The main objective of this research was therefore a comprehensive analysis of relation between the vane expander output power and the heat source temperature. A series of experiments was performed using the micropower ORC test-stand. Results of these experiments are presented here, together with a mathematical description of multivane expanders. The analysis presented in this paper indicates that the output power of multivane expanders depend on the heat source temperature, and that multivane expanders are cheap alternatives to other expanders proposed for micropower ORC systems. Full article

(This article belongs to the Special Issue Organic Rankine Cycle (ORC))

► Show Figures

Figure 1

423 KiB

Open AccessArticle

Multi-Objective Thermo-Economic Optimization Strategy for ORCs Applied to Subcritical and Transcritical Cycles for Waste Heat Recovery

by Steven Lecompte, Sanne Lemmens, Henk Huisseune, Martijn Van den Broek and Michel De Paepe

Energies 2015, 8(4), 2714-2741; https://doi.org/10.3390/en8042714 - 09 Apr 2015

Cited by 63 | Viewed by 7147

Abstract

Organic Rankine cycles (ORCs) are an established technology to convert waste heat to electricity. Although several commercial implementations exist, there is still considerable potential for thermo-economic optimization. As such, a novel framework for designing optimized ORC systems is proposed based on a multi-objective optimization scheme in combination with financial appraisal in a post-processing step. The suggested methodology provides the flexibility to quickly assess several economic scenarios and this without the need of knowing the complex design procedure. This novel way of optimizing and interpreting results is applied to a waste heat recovery case. Both the transcritical ORC and subcritical ORC are investigated and compared using the suggested optimization strategy. Full article

(This article belongs to the Special Issue Organic Rankine Cycle (ORC))

► Show Figures

Figure 1

1185 KiB

Open AccessArticle

Dynamic Simulation and Exergo-Economic Optimization of a Hybrid Solar–Geothermal Cogeneration Plant

by Francesco Calise, Davide Capuano and Laura Vanoli

Energies 2015, 8(4), 2606-2646; https://doi.org/10.3390/en8042606 - 01 Apr 2015

Cited by 46 | Viewed by 7655

Abstract

This paper presents a dynamic simulation model and a parametric analysis of a solar-geothermal hybrid cogeneration plant based on an Organic Rankine Cycle (ORC) powered by a medium-enthalpy geothermal resource and a Parabolic Trough Collector solar field. The fluid temperature supplying heat to the ORC varies continuously as a function of the solar irradiation, affecting both the electrical and thermal energies produced by the system. Thus, a dynamic simulation was performed. The ORC model, developed in Engineering Equation Solver, is based on zero-dimensional energy and mass balances and includes specific algorithms to evaluate the off-design system performance. The overall simulation model of the solar-geothermal cogenerative plant was implemented in the TRNSYS environment. Here, the ORC model is imported, whereas the models of the other components of the system are developed on the basis of literature data. Results are analyzed on different time bases presenting energetic, economic and exergetic performance data. Finally, a rigorous optimization has been performed to determine the set of system design/control parameters minimizing simple payback period and exergy destruction rate. The system is profitable when a significant amount of the heat produced is consumed. The highest irreversibilities are due to the solar field and to the heat exchangers. Full article

(This article belongs to the Special Issue Organic Rankine Cycle (ORC))

► Show Figures

Figure 1

470 KiB

Open AccessArticle

Thermo-Economic Evaluation of Organic Rankine Cycles for Geothermal Power Generation Using Zeotropic Mixtures

by Florian Heberle and Dieter Brüggemann

Energies 2015, 8(3), 2097-2124; https://doi.org/10.3390/en8032097 - 17 Mar 2015

Cited by 83 | Viewed by 11112

Abstract

We present a thermo-economic evaluation of binary power plants based on the Organic Rankine Cycle (ORC) for geothermal power generation. The focus of this study is to analyse if an efficiency increase by using zeotropic mixtures as working fluid overcompensates additional requirements regarding the major power plant components. The optimization approach is compared to systems with pure media. Based on process simulations, heat exchange equipment is designed and cost estimations are performed. For heat source temperatures between 100 and 180 °C selected zeotropic mixtures lead to an increase in second law efficiency of up to 20.6% compared to pure fluids. Especially for temperatures about 160 °C, mixtures like propane/isobutane, isobutane/isopentane, or R227ea/R245fa show lower electricity generation costs compared to the most efficient pure fluid. In case of a geothermal fluid temperature of 120 °C, R227ea and propane/isobutane are cost-efficient working fluids. The uncertainties regarding fluid properties of zeotropic mixtures, mainly affect the heat exchange surface. However, the influence on the determined economic parameter is marginal. In general, zeotropic mixtures are a promising approach to improve the economics of geothermal ORC systems. Additionally, the use of mixtures increases the spectrum of potential working fluids, which is important in context of present and future legal requirements considering fluorinated refrigerants. Full article

(This article belongs to the Special Issue Organic Rankine Cycle (ORC))

► Show Figures

Figure 1

815 KiB

Open AccessArticle

Energy, Exergy and Performance Analysis of Small-Scale Organic Rankine Cycle Systems for Electrical Power Generation Applicable in Rural Areas of Developing Countries

by Suresh Baral, Dokyun Kim, Eunkoo Yun and Kyung Chun Kim

Energies 2015, 8(2), 684-713; https://doi.org/10.3390/en8020684 - 22 Jan 2015

Cited by 51 | Viewed by 11194

Abstract

This paper introduces the concept of installing a small-scale organic Rankine cycle system for the generation of electricity in remote areas of developing countries. The Organic Rankine Cycle Systems (ORC) system uses a commercial magnetically-coupled scroll expander, plate type heat exchangers and plunger type working fluid feed pump. The heat source for the ORC system can be solar energy. A series of laboratory tests were conducted to confirm the cycle efficiency and expander power output of the system. Using the actual system data, the exergy destruction on the system components and exergy efficiency were assessed. Furthermore, the results of the variations of system energy and exergy efficiencies with different operating parameters, such as the evaporating and condensing pressures, degree of superheating, dead state temperature, expander inlet temperature and pressure ratio were illustrated. The system exhibited acceptable operational characteristics with good performance under a wide range of conditions. A heat source temperature of 121 °C is expected to deliver a power output of approximately 1.4 kW. In addition, the system cost analysis and financing mechanisms for the installation of the ORC system were discussed. Full article

(This article belongs to the Special Issue Organic Rankine Cycle (ORC))

► Show Figures

Graphical abstract

1443 KiB

Open AccessArticle

Preliminary Design of Compact Condenser in an Organic Rankine Cycle System for the Low Grade Waste Heat Recovery

by Roberto Capata and Erasmo Zangrillo

Energies 2014, 7(12), 8008-8035; https://doi.org/10.3390/en7128008 - 28 Nov 2014

Cited by 13 | Viewed by 8282

Abstract

The aim of this paper is to present a thermodynamic cycle for the production of electrical power in the 2–5 kW range, suitable for all types of thermally propelled vehicles. The sensible heat recovered from the exhaust gases feeds the energy recovery system, which is able to produce sufficient power to sustain the air conditioning system or other auxiliaries. The working fluids R134a and R245fa have been used in the ORC system, and the systems are simulated by CAMEL-Pro^TM software. The cycles are generated starting from the same heat source: the exhaust gas of a typical 2.0 L Diesel engine (or from a small size turbine engine). The design of the condenser has been performed to obtain a very compact component, evaluating the heat exchanger tube and fins type design. Through empirical formulas, the area of heat exchange, the heat required to exchange and the pressure drop in the element have been calculated. A commercial software package is used to build the model of the condenser, then a thermal and mechanical analysis and a CFD analysis are realized to estimate the heat exchange. Finally the evaluations, the possible future studies and possible improvements of the system are shown. Full article

(This article belongs to the Special Issue Organic Rankine Cycle (ORC))

► Show Figures

Figure 1

2975 KiB

Open AccessArticle

Analyzing the Performance of a Dual Loop Organic Rankine Cycle System for Waste Heat Recovery of a Heavy-Duty Compressed Natural Gas Engine

by Baofeng Yao, Fubin Yang, Hongguang Zhang, Enhua Wang and Kai Yang

Energies 2014, 7(11), 7794-7815; https://doi.org/10.3390/en7117794 - 21 Nov 2014

Cited by 22 | Viewed by 8568

Abstract

A dual loop organic Rankine cycle (DORC) system is designed to recover waste heat from a heavy-duty compressed natural gas engine (CNGE), and the performance of the DORC–CNGE combined system is simulated and discussed. The DORC system includes high-temperature (HT) and low-temperature (LT) cycles. The HT cycle recovers energy from the exhaust gas emitted by the engine, whereas the LT cycle recovers energy from intake air, engine coolant, and the HT cycle working fluid in the preheater. The mathematical model of the system is established based on the first and second laws of thermodynamics. The characteristics of waste heat energy from the CNGE are calculated according to engine test data under various operating conditions. Moreover, the performance of the DORC–CNGE combined system is simulated and analyzed using R245fa as the working fluid. Results show that the maximum net power output and the maximum thermal efficiency of the DORC system are 29.37 kW and 10.81%, respectively, under the rated power output condition of the engine. Compared with the original CNG engine, the maximum power output increase ratio and the maximum brake specific fuel consumption improvement ratio are 33.73% and 25%, respectively, in the DORC–CNGE combined system. Full article

(This article belongs to the Special Issue Organic Rankine Cycle (ORC))

► Show Figures

Figure 1

656 KiB

Open AccessArticle

Thermodynamic Analysis of a Ship Power Plant Operating with Waste Heat Recovery through Combined Heat and Power Production

by Mirko Grljušić, Vladimir Medica and Nikola Račić

Energies 2014, 7(11), 7368-7394; https://doi.org/10.3390/en7117368 - 14 Nov 2014

Cited by 26 | Viewed by 12214

Abstract

The goal of this research is to study a cogeneration plant for combined heat & power (CHP) production that utilises the low-temperature waste energy in the power plant of a Suezmax-size oil tanker for all heating and electricity requirements during navigation. After considering various configurations, a standard propulsion engine operating at maximum efficiency and a CHP Plant with R245fa fluid using a supercritical organic Rankine cycle (ORC) is selected. All the ship heat requirements can be covered by energy of organic fluid after expansion in the turbine, except feeder-booster heating. Hence, an additional quantity of working fluid may be heated using an after Heat Recovery Steam Generator (HRSG) directed to the feeder-booster module. An analysis of the obtained results shows that the steam turbine plant does not yield significant fuel savings. However, a CHP plant with R245fa fluid using supercritical ORC meets all of the demands for electrical energy and heat while burning only a small amount of additional fuel in HRSG at the main engine off-design operation. Full article

(This article belongs to the Special Issue Organic Rankine Cycle (ORC))

► Show Figures

Figure 1

3312 KiB

Open AccessArticle

Preliminary Design and Simulation of a Turbo Expander for Small Rated Power Organic Rankine Cycle (ORC)

by Roberto Capata and Gustavo Hernandez

Energies 2014, 7(11), 7067-7093; https://doi.org/10.3390/en7117067 - 03 Nov 2014

Cited by 31 | Viewed by 11134

Abstract

Nowadays, the Organic Rankine Cycle (ORC) system, which operates with organic fluids, is one of the leading technologies for “waste energy recovery”. It works as a conventional Rankine Cycle but, as mentioned, instead of steam/water, an organic fluid is used. This change allows it to convert low temperature heat into electric energy where required. Large numbers of studies have been carried out to identify the most suitable fluids, system parameters and the various configurations. In the present market, most ORC systems are designed and manufactured for the recovery of thermal energy from various sources operating at “large power rating” (exhaust gas turbines, internal combustion engines, geothermal sources, large melting furnaces, biomass, solar, etc.); from which it is possible to produce a large amount of electric energy (30 kW ÷ 300 kW). Such applications for small nominal power sources, as well as the exhaust gases of internal combustion engines (car sedan or town, ships, etc.) or small heat exchangers, are very limited. The few systems that have been designed and built for small scale applications, have, on the other hand, different types of expander (screw, scroll, etc.). These devices are not adapted for placement in small and restricted places like the interior of a conventional car. The aim of this work is to perform the preliminary design of a turbo-expander that meets diverse system requirements such as low pressure, small size and low mass flow rates. The expander must be adaptable to a small ORC system utilizing gas of a diesel engine or small gas turbine as thermal source to produce 2–10 kW of electricity. The temperature and pressure of the exhaust gases, in this case study (400–600 °C and a pressure of 2 bar), imposes a limit on the use of an organic fluid and on the net power that can be produced. In addition to water, fluids such as CO₂, R134a and R245fa have been considered. Once the operating fluids has been chosen, the turbine characteristics (dimensions, input and output temperature, pressure ratio, etc.) have been calculated and an attempt to find the “nearly-optimal” combination has been carried out. The detailed design of a radial expander is presented and discussed. A thermo-mechanical performance study was carry out to verify structural tension and possible displacement. On the other hand, preliminary CFD analyses have been performed to verify the effectiveness of the design procedure. Full article

(This article belongs to the Special Issue Organic Rankine Cycle (ORC))

► Show Figures

Figure 1

1012 KiB

Open AccessArticle

Optimization of Design Pressure Ratio of Positive Displacement Expander for Vehicle Engine Waste Heat Recovery

by Young Min Kim, Dong Gil Shin and Chang Gi Kim

Energies 2014, 7(9), 6105-6117; https://doi.org/10.3390/en7096105 - 22 Sep 2014

Cited by 19 | Viewed by 6273

Abstract

This study investigated the effect of the built-in volume ratio of an expander on the performance of a dual-loop Rankine cycle system for the engine waste heat recovery of a vehicle. Varying vehicle operating conditions can cause a positive displacement expander to operate in both under- and over-expansion states. Therefore, analysis of the off-design performance of the expander is very important. Furthermore, the volume and weight of the expander must be considered in its optimization along with the efficiency. A simple modeling of the off-design operation of the expander showed that a built-in volume ratio that causes under-expansion rather than over-expansion at the target condition is more desirable. Full article

(This article belongs to the Special Issue Organic Rankine Cycle (ORC))

► Show Figures

Figure 1

Review

Jump to: Research

1263 KiB

Open AccessReview

Systematic Methods for Working Fluid Selection and the Design, Integration and Control of Organic Rankine Cycles—A Review

by Patrick Linke, Athanasios I. Papadopoulos and Panos Seferlis

Energies 2015, 8(6), 4755-4801; https://doi.org/10.3390/en8064755 - 26 May 2015

Cited by 118 | Viewed by 10075

Abstract

Efficient power generation from low to medium grade heat is an important challenge to be addressed to ensure a sustainable energy future. Organic Rankine Cycles (ORCs) constitute an important enabling technology and their research and development has emerged as a very active research field over the past decade. Particular focus areas include working fluid selection and cycle design to achieve efficient heat to power conversions for diverse hot fluid streams associated with geothermal, solar or waste heat sources. Recently, a number of approaches have been developed that address the systematic selection of efficient working fluids as well as the design, integration and control of ORCs. This paper presents a review of emerging approaches with a particular emphasis on computer-aided design methods. Full article

(This article belongs to the Special Issue Organic Rankine Cycle (ORC))

► Show Figures

Figure 1

770 KiB

Open AccessReview

Part-Load Performance of aWet Indirectly Fired Gas Turbine Integrated with an Organic Rankine Cycle Turbogenerator

by Leonardo Pierobon, Tuong-Van Nguyen, Andrea Mazzucco, Ulrik Larsen and Fredrik Haglind

Energies 2014, 7(12), 8294-8316; https://doi.org/10.3390/en7128294 - 11 Dec 2014

Cited by 21 | Viewed by 9550

Abstract

Over the last years, much attention has been paid to the development of efficient and low-cost power systems for biomass-to-electricity conversion. This paper aims at investigating the design- and part-load performance of an innovative plant based on a wet indirectly fired gas turbine (WIFGT) fueled by woodchips and an organic Rankine cycle (ORC) turbogenerator. An exergy analysis is performed to identify the sources of inefficiencies, the optimal design variables, and the most suitable working fluid for the organic Rankine process. This step enables to parametrize the part-load model of the plant and to estimate its performance at different power outputs. The novel plant has a nominal power of 250 kW and a thermal efficiency of 43%. The major irreversibilities take place in the burner, recuperator, compressor and in the condenser. Toluene is the optimal working fluid for the organic Rankine engine. The part-load investigation indicates that the plant can operate at high efficiencies over a wide range of power outputs (50%–100%), with a peak thermal efficiency of 45% at around 80% load. While the ORC turbogenerator is responsible for the efficiency drop at low capacities, the off-design performance is governed by the efficiency characteristics of the compressor and turbine serving the gas turbine unit. Full article

(This article belongs to the Special Issue Organic Rankine Cycle (ORC))

► Show Figures

Journal Menu

Journal Browser

Organic Rankine Cycle (ORC)

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (14 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI