scholarly journals NUMERICAL INVESTIGATION OF A SOLAR-DRIVEN ORGANIC RANKINE CYCLE COUPLED TO A GEOTHERMAL FIELD

2021 ◽  
pp. 087
Author(s):  
Saša Pavlović ◽  
Evangelos Bellos ◽  
Milan Grozdanović
Keyword(s):  
Renewable Energy Sources ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Geothermal Field ◽  
Solar Irradiation ◽  
Thermodynamic Efficiency ◽  
Total Thermal Conductivity ◽  
Irradiation Level ◽  
Field Efficiency ◽  
Solar Field

The objective of this work is to investigate a solar-driven Organic Rankine Cycle (ORC) for power production with a geothermal well as the heat sink for the ORC condenser. The examined unit combines the exploitation of two renewable energy sources. Solar irradiation is exploited by using solar dish concentrators with spiral absorbers, while the geothermal field includes vertical boreholes with U-tubes. The system is investigated parametrically with a developed model in Engineering Equation Solver, and the examined parameters are the solar beam irradiation level, the total thermal conductivity of the ORC condenser, the borehole length, the number of the boreholes and the mean ground temperature. For the default scenario, it is found that system electrical efficiency is 21.45%, the ORC’s thermodynamic efficiency is 35.99%, and the solar field efficiency is 61.30%. Moreover, it is found that the examined system is 5.7% more efficient than a conventional air-cooled condenser system.

Numerical Analysis of a Solar Organic Rankine Cycle (ORC) Unit With R245fa as Working Fluid

2012 ◽  
Author(s):  
Musbaudeen O. Bamgbopa ◽  
Eray Uzgoren
Keyword(s):  
Mass Flow ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Hot Water ◽  
Critical Parameters ◽  
Working Fluid ◽  
Flow Rates ◽  
Steady State Operation ◽  
Mass Flow Rates ◽  
Solar Field

This paper presents a solar Organic Rankine Cycle (ORC) for electricity generation; where a regression based approach is used for the working fluid. Models of the unit’s sub-components (pump, evaporator, expander and condenser) are also presented. Heat supplied by the solar field can heat the water up to 80–95 °C at mass flow rates of 2–12 kg/s and deliver energy to the ORC’s heat exchanger unit. Simulation results of steady state operation using the developed model shows a maximum power output of around 40 kWe. Both refrigerant and hot water mass flow rates in the system are identified as critical parameters to optimize the power production and the cycle efficiency.

scholarly journals Performance comparison of the solar-driven supercritical organic Rankine cycle coupled with the vapour-compression refrigeration cycle

Clean Energy ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 476-491
Author(s):  
Yunis Khan ◽  
Radhey Shyam Mishra
Keyword(s):  
Thermal Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Coefficient Of Performance ◽  
Solar Irradiation ◽  
Working Fluid ◽  
Refrigeration Cycle ◽  
Exergy Destruction ◽  
Cogeneration System ◽  
Vapour Compression

Abstract In this study, a parametric analysis was performed of a supercritical organic Rankine cycle driven by solar parabolic trough collectors (PTCs) coupled with a vapour-compression refrigeration cycle simultaneously for cooling and power production. Thermal efficiency, exergy efficiency, exergy destruction and the coefficient of performance of the cogeneration system were considered to be performance parameters. A computer program was developed in engineering equation-solver software for analysis. Influences of the PTC design parameters (solar irradiation, solar-beam incidence angle and velocity of the heat-transfer fluid in the absorber tube), turbine inlet pressure, condenser and evaporator temperature on system performance were discussed. Furthermore, the performance of the cogeneration system was also compared with and without PTCs. It was concluded that it was necessary to design the PTCs carefully in order to achieve better cogeneration performance. The highest values of exergy efficiency, thermal efficiency and exergy destruction of the cogeneration system were 92.9%, 51.13% and 1437 kW, respectively, at 0.95 kW/m2 of solar irradiation based on working fluid R227ea, but the highest coefficient of performance was found to be 2.278 on the basis of working fluid R134a. It was also obtained from the results that PTCs accounted for 76.32% of the total exergy destruction of the overall system and the cogeneration system performed well without considering solar performance.

scholarly journals A COMPREHENSIVE ENERGETIC, EXERGETIC AND HEAT TRANSFER ANALYSIS OF A SOLAR ORGANIC RANKINE SYSTEM

2021 ◽  
Vol 20 (1) ◽  
pp. 100
Author(s):  
A. E. Achiles ◽  
J. V. H. D’Angelo
Keyword(s):  
Heat Transfer ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Heat Transfer Analysis ◽  
Environmental Concerns ◽  
Power Block ◽  
Transfer Behavior ◽  
Organic Rankine Cycles ◽  
Solar Resource ◽  
Solar Field

Environmental concerns have been motivating the use of renewable energysources to meet sustainable requirements. In this context, concentrated solarpower driven by organic Rankine cycles has been classified as an up-andcomingtechnology to generate energy under low and moderate temperatures.In order to have a better understanding of the availability and utilization of thisenergy resource, the purpose of the present study is to perform acomprehensive energetic, exergetic and heat transfer analysis of a 200 kWsolar organic Rankine cycle through the presentation of the energy and exergyefficiencies and losses for each component; the exergy destruction at all stagesof the process; and the heat transfer behavior along the receiver. The thermalmodel was developed in Engineering Equation Solver and validated withliterature data. The solar collector was operated with Therminol 66 and theworking fluid employed in the power block was cyclohexane. The energeticefficiencies achieved in the solar field, power block, and overall system were64.97; 21.36; and 13.87 %, respectively. Considering the exergetic efficiencies,they were 27.37; 54.45; and 14.89 %, respectively. The solar resource variationshowed that the higher DNI value, the better the system performance.

scholarly journals Development of a Small Solar Thermal Power Plant for Heat and Power Supply to Domestic and Small Business Buildings

2018 ◽  
Author(s):  
Khamid Mahkamov ◽  
Piero Pili ◽  
Roberto Manca ◽  
Arthur Leroux ◽  
Andre Charles Mintsa ◽  
...  
Keyword(s):  
Power Plant ◽  
Latent Heat ◽  
Thermal Power Plant ◽  
Thermal Power ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Thermal Storage ◽  
Solar Thermal ◽  
Solar Thermal Power ◽  
Solar Field

The small solar thermal power plant is being developed with funding from EU Horizon 2020 Program. The plant is configured around a 2-kWel Organic Rankine Cycle turbine and solar field, made of Fresnel mirrors. The solar field is used to heat thermal oil to the temperature of about 240 °C. This thermal energy is used to run the Organic Rankine Cycle turbine and the heat rejected in its condenser (about 18-kWth) is utilized for hot water production and living space heating. The plant is equipped with a latent heat thermal storage to extend its operation by about 4 hours during the evening building occupancy period. The phase change material used is Solar salt with the melting/solidification point at about 220 °C. The total mass of the PCM is about 3,800 kg and the thermal storage capacity is about 100 kWh. The operation of the plant is monitored by a central controller unit. The main components of the plant are being manufactured and laboratory tested with the aim to assemble the plant at the demonstration site, located in Catalonia, Spain. At the first stage of investigations the ORC turbine will be directly integrated with the solar filed to evaluate their joint performance. During the second stage of tests, the Latent Heat Thermal Storage will be incorporated into the plant and its performance during the charging and discharging processes will be investigated. It is planned that the continuous filed tests of the whole plant will be performed during the 2018–2019 period.

scholarly journals Optimal boiling temperature for ORC installation

2012 ◽  
Vol 33 (3) ◽  
pp. 25-35 ◽  
Author(s):  
Jarosław Mikielewicz ◽  
Dariusz Mikielewicz
Keyword(s):  
Objective Function ◽  
Organic Rankine Cycle ◽  
Cost Effective ◽  
Rankine Cycle ◽  
Optimization Method ◽  
Boiling Temperature ◽  
Critical Conditions ◽  
Working Fluid ◽  
Thermodynamic Efficiency ◽  
Inlet Temperature

Abstract In the paper a research on cost-effective optimum design boiling temperature for Organic Rankine Cycle utilizing low-temperature heat sources is presented. The ratio of the heat exchanger area of the boiler to the power output is used as the objective function. Analytical relations for heat transfer area as well power of the cycle are formulated. Evaporation temperature and inlet temperature of the heat source medium as well its mass flow rate are varied in the optimization method. The optimization is carried out for three working fluids, i.e. R 134a, water and ethanol. The objective function (economics profitability, thermodynamic efficiency) leads to different optimal working conditions in terms of evaporating temperature. Maximum power generation in the near-critical conditions of subcritical ORC is the highest. The choice of the working fluid can greatly affect the objective function which is a measure of power plant cost. Ethanol exhibits a minimum objective function but not necessarily the maximum cycle efficiency.

scholarly journals Techno-Economic Optimization of Medium Temperature Solar-Driven Subcritical Organic Rankine Cycle

Thermo ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 77-105
Author(s):  
Tryfon C. Roumpedakis ◽  
Nikolaos Fostieris ◽  
Konstantinos Braimakis ◽  
Evropi Monokrousou ◽  
Antonios Charalampidis ◽  
...  
Keyword(s):  
Storage Tank ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Small Scale ◽  
Medium Temperature ◽  
Working Fluids ◽  
Solar Conversion ◽  
Tank Capacity ◽  
Solar Field ◽  
Field Area

The present work focuses on the techno-economic assessment and multi-objective genetic algorithm optimization of small-scale (40 kWth input), solar Organic Rankine Cycle (ORC) systems driven by medium-to-high temperature (up to 210 °C) parabolic dish (PDC) and trough (PTC) collectors. The ORCs are designed to maximize their nominal thermal efficiency for several natural hydrocarbon working fluids. The optimization variables are the solar field area and storage tank capacity, with the goal of minimizing the levelized cost of produced electricity (LCoE) and maximizing the annual solar conversion efficiency. The lowest LCOE (0.34 €/kWh) was obtained in Athens for a high solar field area and low storage tank capacity. Meanwhile, the maximum annual solar conversion efficiencies (10.5–11%) were obtained in northern cities (e.g., Brussels) at lower solar field locations. While PTCs and PDCs result in similar efficiencies, the use of PTCs is more cost-effective. Among the working fluids, Cyclopentane and Cyclohexane exhibited the best performance, owing to their high critical temperatures. Notably, the systems could be more profitable at higher system sizes, as indicated by the 6% LCoE decrease of the solar ORC in Athens when the nominal heat input was increased to 80 kWth.

scholarly journals Application of Solar Organic Rankine System for Energy Generation in Buildings: the Case of Athens

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Organic Rankine Cycle ◽  
Statistical Processing ◽  
Rankine Cycle ◽  
Total Solar Irradiance ◽  
Working Fluid ◽  
Small Scale ◽  
Thermodynamic Efficiency ◽  
Climate Data ◽  
Local Climate ◽  
Computer Codes

This paper describes the performance of an ORC system driven by solar energy and R134a as working fluid. The system is predicted along the twelve months of the year. The operation of the system and the related thermodynamics are simulated by suitable computer codes and the required local climate data are determined by statistical processing over a considerable number of years. It’s found that the solar to electricity efficiency of this SORC system varies from 0.049 to 0.058 while the ambient temperature varies from 11.3oC to 29.2oC and the total solar irradiance varies from 443 W/m2 to 679 W/m2. The system’s arrangement comprises a solar thermal array which is coupled with an organic Rankine engine. The mean annual overall efficiency of the SORC system is estimated at 0.055 while the thermodynamic efficiency of Rankine is calculated at 0.107. The obvious advantage of this arrangement is that electricity can be produced in buildings by using the existing common solar thermals installed. Easy–to–find machinery is employed in order to attain a simple and practical small–scale organic Rankine cycle arrangement coupled with common solar thermals used widely in Greek buildings for DHW production and space heating assistance.

scholarly journals The IRC-PD Tool: A Code to Design Steam and Organic Waste Heat Recovery Units

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5611
Author(s):  
Youcef Redjeb ◽  
Khatima Kaabeche-Djerafi ◽  
Anna Stoppato ◽  
Alberto Benato
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Renewable Energy Sources ◽  
Safety Information ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Industrial Processes ◽  
Working Fluid ◽  
Energy Sources

The Algerian economy and electricity generation sector are strongly dependent on fossil fuels. Over 93% of Algerian exports are hydrocarbons, and approximately 90% of the generated electricity comes from natural gas power plants. However, Algeria is also a country with huge potential in terms of both renewable energy sources and industrial processes waste heat recovery. For these reasons, the government launched an ambitious program to foster renewable energy sources and industrial energy efficiency. In this context, steam and organic Rankine cycles could play a crucial role; however, there is a need for reliable and time-efficient optimization tools that take into account technical, economic, environmental, and safety aspects. For this purpose, the authors built a mathematical tool able to optimize both steam and organic Rankine units. The tool, called Improved Rankine Cycle Plant Designer, was developed in MATLAB environment, uses the Genetic Algorithm toolbox, acquires the fluids thermophysical properties from CoolProp and REFPROP databases, while the safety information is derived from the ASHRAE database. The tool, designed to support the development of both RES and industrial processes waste heat recovery, could perform single or multi-objective optimizations of the steam Rankine cycle layout and of a multiple set of organic Rankine cycle configurations, including the ones which adopt a water or an oil thermal loop. In the case of the ORC unit, the working fluid is selected among more than 120 pure fluids and their mixtures. The turbines’ design parameters and the adoption of a water- or an air-cooled condenser are also optimization results. To facilitate the plant layout and working fluid selection, the economic analysis is performed to better evaluate the plant economic feasibility after the thermodynamic optimization of the cycle. Considering the willingness of moving from a fossil to a RES-based economy, there is a need for adopting plants using low environmental impact working fluids. However, because ORC fluids are subjected to environmental and safety issues, as well as phase out, the code also computes the Total Equivalent Warming Impact, provides safety information using the ASHRAE database, and displays an alert if the organic substance is phased out or is going to be banned. To show the tool’s potentialities and improve the knowledge on waste heat recovery in bio-gas plants, the authors selected an in-operation facility in which the waste heat is released by a 1 MWel internal combustion engine as the test case. The optimization outcomes reveal that the technical, economic, environmental, and safety performance can be achieved adopting the organic Rankine cycle recuperative configuration. The unit, which adopts Benzene as working fluid, needs to be decoupled from the heat source by means of an oil thermal loop. This optimized solution guarantees to boost the electricity production of the bio-gas facility up to 15%.

Performance Analysis of Solar-Powered Organic Rankine Cycle With Energy Storage in Different Climate Zones in the United States

2021 ◽  
Vol 143 (9) ◽  
Author(s):  
Hadis Hemmati ◽  
Jian Zhang ◽  
Emily Spayde ◽  
Pedro J. Mago ◽  
Heejin Cho
Keyword(s):  
United States ◽  
Energy Consumption ◽  
Energy Storage ◽  
Electric Energy ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
The United States ◽  
Solar Irradiation ◽  
Climate Zones ◽  
Solar Powered

Abstract Solar-powered organic Rankine cycle (ORC) is considered a promising technology and has the potential to provide clean electric energy. Extensive studies on the design of ORC systems have been conducted and reported in the literature. However, few studies have presented the influence of climate zones on the performance of a solar-powered ORC, especially for an integrated ORC and energy storage system. This paper presents an analysis to determine the performance of solar-powered ORCs with electric energy storage (EES) systems to supply electricity to buildings in different climate zones in the United States. The building type evaluated in this paper is a large office, and the energy consumption of the facility in each climate location was determined using EnergyPlus. The ORC-EES operational strategy used in this investigation is described as follows: when solar irradiation is adequate to produce power, the ORC charges the EES. Then, when there is no solar energy available, the EES provides power to the building. The ORC-EES is evaluated based on the potential to reduce the operational cost, the primary energy consumption, and the carbon dioxide emission. Furthermore, the influence of the number of solar collectors and the EES size on the performance of the ORC-EES system is investigated.

Performance Analysis of OTEC Plants With Multilevel Organic Rankine Cycle and Solar Hybridization

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Paola Bombarda ◽  
Costante Invernizzi ◽  
Mario Gaia
Keyword(s):  
Water Flow ◽  
Cold Water ◽  
Renewable Energy Sources ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Warm Water ◽  
Late Nineteenth Century ◽  
Ocean Energy ◽  
Commercial Plant ◽  
Under Construction

Among the renewable energy sources, ocean energy is encountering an increasing interest. Several technologies can be applied in order to convert the ocean energy into electric power: among these, ocean thermal energy conversion (OTEC) is an interesting technology in the equatorial and tropical belt, where the temperature difference between surface warm water and deep cold water allows one to implement a power cycle. Although the idea is very old (it was first proposed in the late nineteenth century), no commercial plant has ever been built. Nevertheless, a large number of studies are being conducted at the present time, and several prototypes are under construction. A few studies concern hybrid solar-ocean energy plants: in this case, the ocean thermal gradient, which is usually comprised in the range 20–25 °C in the favorable belt, can be increased during daytime, thanks to the solar contribution. This paper addresses topics that are crucial in order to make OTEC viable, and some technical solutions are suggested and evaluated. The closed cycle option is selected and implemented by means of an organic Rankine cycle (ORC) power plant, featuring multiple ORC modules in series on the warm water flow; with a three-level cycle, the performance is approximately 30% better if compared to the single-level cycle. In addition, the hybrid solar-OTEC plant is considered in order to investigate the obtainable performance during both day and night operation; this option could provide efficiency benefit, allowing one to almost triplicate the energy produced during daytime for the same prescribed water flow.

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