Performance Investigation of Solar Organic Rankine Cycle System With Zeotropic Working Fluid Mixtures for Use in Micro-Cogeneration

2021 ◽  
Vol 143 (9) ◽  
Author(s):  
Wahiba Yaïci ◽  
Evgueniy Entchev ◽  
Pouyan Talebizadehsardari ◽  
Michela Longo
Keyword(s):  
Low Temperature ◽  
Power Output ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Condensation Temperature ◽  
Source Temperature ◽  
Thermodynamic Performance ◽  
Net Power Output ◽  
Cycle Efficiency

Abstract Overall, there are numerous sustainable sources of renewable, low-temperature heat, principally solar energy, geothermal energy, and energy produced from industrial wastes. Extended utilization of these low-temperature alternatives has a certain capacity of decreasing fossil fuel use with its associated very hazardous greenhouse gas emissions. Researchers have commonly recognized the organic Rankine cycle (ORC) as a feasible and suitable system to produce electrical power from renewable sources based on its advantageous use of volatile organic fluids as working fluids (WFs). Researchers have similarly shown an affinity to the exploitation of zeotropic mixtures as ORC WFs due to their capability to enhance the thermodynamic performance of ORC systems, an achievement supported by improved fits of the temperature profiles of the WF and the heat source/sink. This paper determines both the technical feasibility and the benefits of using zeotropic mixtures as WFs by means of a simulation study of an ORC system. This study analyzes the thermodynamic performance of ORC systems using zeotropic WF mixtures to produce electricity driven by low-temperature solar heat sources for use in buildings. A thermodynamic model is created with an ORC system with and without a regenerator. Five zeotropic mixtures with diverse compositions between 0 and 1 in 0.2 increments of R245fa/propane, R245fa/hexane, R245fa/heptane, pentane/hexane, and isopentane/hexane are assessed and compared with identify the best blends of mixtures that are able to produce superior efficiency in their system cycles. Results disclosed that R245fa/propane (0.4/0.6) with regenerator produces the highest net power output of 7.9 kW and cycle efficiency of 9.4% at the operating condition with a hot source temperature of 85 °C. The study also investigates the effects of the volume flow ratio, and evaporation and condensation temperature glide on the ORC’s thermodynamic performance. Following a thorough analysis of each mixture, R245fa/propane is chosen for a parametric study to examine the effects of operating factors on the system’s efficiency and sustainability index. It was found that the highest cycle efficiency and highest second law cycle efficiency of around 10.5% and 84.0%, respectively, were attained with a mass composition of 0.6/0.4 at the hot source temperature of 95 °C and cold source temperature of 20 °C with a net power output of 9.6 kW. Moreover, results revealed that for zeotropic mixtures, there is an optimal composition range within which binary mixtures are tending to work more efficiently than the component pure fluids. In addition, a significant increase in cycle efficiency can be achieved with a regenerative ORC, with cycle efficiency in the range 3.1–9.8% versus 8.6–17.4% for ORC both without and with regeneration, respectively. In conclusion, utilizing zeotropic mixtures may well expand the restriction faced in choosing WFs for solar-powered ORC-based micro-combined heat and power (CHP) systems.

Performance Investigation of Solar Organic Rankine Cycle Systems With and Without Regeneration and With Zeotropic Working Fluid Mixtures for Use in Micro-Cogeneration

2020 ◽  
Author(s):  
Wahiba Yaïci ◽  
Evgueniy Entchev ◽  
Pouyan Talebizadeh Sardari
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
High Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Industrial Wastes ◽  
Working Fluid ◽  
Condensation Temperature ◽  
Thermodynamic Performance ◽  
Cycle Efficiency

Abstract Globally there are several viable sources of renewable, low-temperature heat (below 130°C) particularly solar energy, geothermal energy, and energy generated from industrial wastes. Increased exploitation of these low-temperature options has the definite potential of reducing fossil fuel consumption with its attendant very harmful greenhouse gas emissions. Researchers have universally identified the organic Rankine cycle (ORC) as a practicable and promising system to generate electrical power from renewable sources based on its beneficial use of volatile organic fluids as working fluids (WFs). In recent times, researchers have also shown a preference for/an inclination towards deployment of zeotropic mixtures as ORC WFs because of their capacity to improve thermodynamic performance of ORC systems, a feat enabled by better matches of the temperature profiles of the WF and the heat source/sink. This paper demonstrates both the technical feasibility and the notable advantages of using zeotropic mixtures as WFs through a simulation study of an ORC system. The study examines the thermodynamic performance of ORC systems using zeotropic WF mixtures to generate electricity driven by low-temperature solar heat source for building applications. A thermodynamic model is developed with an ORC system both with and excluding a regenerator. Five zeotropic mixtures with varying compositions of R245fa/propane, R245fa/hexane, R245fa/heptane, pentane/hexane and isopentane/hexane are evaluated and compared to identify the best combinations of WF mixtures that can yield high efficiency in their system cycles. The study also investigates the effects of the volumetric flow ratio, and evaporation and condensation temperature glides on the ORC’s thermodynamic performance. Following a detailed analysis of each mixture, R245fa/propane is selected for parametric study to examine the effects of operating parameters on the system’s efficiency and sustainability index. For zeotropic mixtures, results showed that there is an optimal composition range within which binary mixtures are inclined to perform more efficiently than the component pure fluids. In addition, a significant increase in cycle efficiency can be achieved with a regenerative ORC, with cycle efficiency ranging between 3.1–9.8% and 8.6–17.4% for ORC both without and with regeneration, respectively. Results also showed that exploiting zeotropic mixtures could enlarge the limitation experienced in selecting WFs for low-temperature solar organic Rankine cycles.

scholarly journals Thermodynamic, Economic and Sustainability Analysis of Solar Organic Rankine Cycle System with Zeotropic Working Fluid Mixtures for Micro-Cogeneration in Buildings

2020 ◽  
Vol 10 (21) ◽  
pp. 7925
Author(s):  
Wahiba Yaïci ◽  
Evgueniy Entchev ◽  
Pouyan Talebizadehsardari ◽  
Michela Longo
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Optimum Operating ◽  
Working Fluid ◽  
Condensation Temperature ◽  
Fluid Mixtures ◽  
Thermodynamic Performance ◽  
Cycle Efficiency

Globally there are several viable sources of renewable, low-temperature heat (below 130 °C), particularly solar energy, geothermal energy, and energy generated from industrial wastes. Increased exploitation of these low-temperature options has the definite potential of reducing fossil fuel consumption with its attendant very harmful greenhouse gas emissions. Researchers have universally identified the organic Rankine cycle (ORC) as a practicable and suitable system to generate electrical power from renewable sources based on its beneficial usage of volatile organic fluids as working fluids (WFs). In recent times, researchers have also shown a preference towards deployment of zeotropic mixtures as ORC WFs because of their capacity to improve thermodynamic performance of ORC systems, a feat enabled through the greater matching of the temperature profiles of the WF and the heat source/sink. This paper demonstrates the thermodynamic, economic and sustainability feasibility, and the notable advantages of using zeotropic mixtures as WFs through a simulation study of an ORC system. The study examines first the thermodynamic performance of ORC systems using zeotropic mixtures to generate electricity powered by a low-temperature solar heat source for building applications. A thermodynamic model is developed with a solar-driven ORC system both with and excluding a regenerator. Twelve zeotropic mixtures with varying compositions are evaluated and compared to identify the best combinations of mixtures that can yield high performance and high efficiency in their system cycles. The study also examines the effects of the volume flow ratio, and evaporation and condensation temperature glides on the ORC’s thermodynamic performance. Following a detailed analysis of each mixture, R245fa/propane and butane/propane are selected for parametric study to investigate the influence of operating parameters on the system’s efficiency and sustainability index. For zeotropic mixtures, results disclosed that there is an optimal composition range within which binary mixtures are inclined to perform more efficiently than the component pure fluids. In addition, a substantial enhancement in cycle efficiency can be obtained by a regenerative ORC, with cycle efficiency ranging between 3.1–9.8% and 8.6–17.4% for ORC both without and with regeneration, respectively. Results also revealed that exploiting zeotropic mixtures could enlarge the limitation experienced in selecting WFs for low-temperature solar ORCs. Moreover, a detailed economic with a sensitivity analysis of the solar ORC system was performed to evaluate the cost of the electricity and other economic criteria. The outcome of this investigation should be useful in the thermo-economic feasibility assessments of solar-driven ORC systems using working fluid mixtures to find the optimum operating range for maximum performance and minimum cost.

scholarly journals Investigation of a thermo-fluidic exchange pump in trilateral flash and organic Rankine cycles / trans. from Engl. M. A. Fedorova

2020 ◽  
Vol 4 (4) ◽  
pp. 66-74
Author(s):  
C. R. Baggley ◽  
◽  
M. G. Read ◽  
Keyword(s):  
Low Temperature ◽  
Power Output ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Vapour Phase ◽  
Working Fluid ◽  
Positive Displacement ◽  
Wide Range ◽  
Work Input ◽  
Net Power Output

It is well known that large amounts of energy loss occurs at low temperature states in a wide range of industrial processes., The recovery and reuse of this energy is at the forefront of increasing the overall efficiencies of industrial systems. The aim of this paper is to investigate the effectiveness of using a Thermo-Fluidic Exchange (TFE) pump at low temperature conditions in both a SaturatedVapour Organic Rankine Cycle (SORC) and a Trilateral Flash Cycle (TFC). For some low temperature applications, TFCs have been shown to achieve higher net power output than conventional SORCs, due to their ability to extract more heat from the source fluid. This is the subject of current research as a result of advancements made in the design of positive displacement machines for operation as twophase expanders. Conventional turbines cannot be used for TFCs as they must operate in the vapour phase. One drawback of the TFC is the higher working fluid mass flow rate required. Depending on the scale of the system, this can potentially cause difficulties with pump selection. A TFE pump uses heat input to the system to increase the pressure and temperature of the working fluid, rather than the work input in a standard mechanical pump. This paper compares the net power output achievable using both mechanical and TFE pumps with SORC and TFC systems. The results suggest that the TFE pump could be a viable option for TFC systems

Organic Rankine Cycle Optimization With Explicit Designs of Evaporator and Radial Inflow Turbine

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Hasan Eren Bekiloğlu ◽  
Hasan Bedir ◽  
Günay Anlaş
Keyword(s):  
Power Output ◽  
Pressure Ratio ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Working Fluids ◽  
Source Temperature ◽  
Order Preference ◽  
Radial Inflow Turbine ◽  
Net Power Output

Abstract Although there are studies on optimizing organic Rankine cycles (ORCs) through individual components, in this study, for the first time, both evaporator and turbine designs are included in a multiobjective optimization. Twenty-eight working fluids are used to find optimum cycle parameters for three source temperatures (90, 120, and 150 °C). A mean-line radial inflow turbine model is used. Nondominated Sorting Genetic Algorithm II is utilized to minimize total evaporator area per net power output and maximize performance factor simultaneously. The technique for Order Preference by Similarity to Ideal Situation (TOPSIS) procedure is followed to obtain ideal solutions. A group of working fluids with highest net power output is determined for each heat source temperature. Optimized geometric parameters of the evaporator vary in a narrow range independent of the working fluid and the source temperature, but evaporator PPTD and degree of superheating depend on the working fluid. The specific speed, the pressure ratio through the turbine, and the nozzle inlet-to-outlet radius ratio do not change significantly with cycle conditions.

Waste Heat Recovery in a Cruise Vessel in the Baltic Sea by Using an Organic Rankine Cycle: A Case Study

2015 ◽  
Author(s):  
Fredrik Ahlgren ◽  
Maria E. Mondejar ◽  
Magnus Genrup ◽  
Marcus Thern
Keyword(s):  
Power Output ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Maritime Transportation ◽  
Working Fluid ◽  
Net Power Output

Maritime transportation is a significant contributor to SOx, NOx and particle matter emissions, even though it has a quite low CO2 impact. New regulations are being enforced in special areas that limit the amount of emissions from the ships. This fact, together with the high fuel prices, is driving the marine industry towards the improvement of the energy efficiency of current ship engines and the reduction of their energy demand. Although more sophisticated and complex engine designs can improve significantly the efficiency of the energy systems in ships, waste heat recovery arises as the most influent technique for the reduction of the energy consumption. In this sense, it is estimated that around 50% of the total energy from the fuel consumed in a ship is wasted and rejected in fluid and exhaust gas streams. The primary heat sources for waste heat recovery are the engine exhaust and the engine coolant. In this work, we present a study on the integration of an organic Rankine cycle (ORC) in an existing ship, for the recovery of the main and auxiliary engines exhaust heat. Experimental data from the operating conditions of the engines on the M/S Birka Stockholm cruise ship were logged during a port-to-port cruise from Stockholm to Mariehamn over a period of time close to one month. The ship has four main engines Wärtsilä 5850 kW for propulsion, and four auxiliary engines 2760 kW used for electrical consumers. A number of six load conditions were identified depending on the vessel speed. The speed range from 12–14 knots was considered as the design condition, as it was present during more than 34% of the time. In this study, the average values of the engines exhaust temperatures and mass flow rates, for each load case, were used as inputs for a model of an ORC. The main parameters of the ORC, including working fluid and turbine configuration, were optimized based on the criteria of maximum net power output and compactness of the installation components. Results from the study showed that an ORC with internal regeneration using benzene would yield the greatest average net power output over the operating time. For this situation, the power production of the ORC would represent about 22% of the total electricity consumption on board. These data confirmed the ORC as a feasible and promising technology for the reduction of fuel consumption and CO2 emissions of existing ships.

scholarly journals Comparison of single and double stage regenerative organic rankine cycle for medium grade heat source through energy and exergy estimation

2019 ◽  
Vol 8 (2) ◽  
pp. 141 ◽  
Author(s):  
Ghalya Pikra ◽  
Nur Rohmah
Keyword(s):  
Heat Source ◽  
Flow Rate ◽  
Power Output ◽  
Thermal Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Working Fluid ◽  
Energy And Exergy ◽  
Net Power Output

Regenerative organic Rankine cycle (RORC) can be used to improve organic Rankine cycle (ORC) performance. This paper presents a comparison of a single (SSRORC) and double stage regenerative organic Rankine cycle (DSRORC) using a medium grade heat source. Performance for each system is estimated using the law of thermodynamics I and II through energy and exergy balance. Solar thermal is used as the heat source using therminol 55 as a working fluid, and R141b is used as the organic working fluid. The initial data for the analysis are heat source with 200°C of temperature, and 100 L/min of volume flow rate. Analysis begins by calculating energy input to determine organic working fluid mass flow rate, and continued by calculating energy loss, turbine power and pump power consumption to determine net power output and thermal efficiency. Exergy analysis begins by calculating exergy input to determine exergy efficiency. Exergy loss, exergy destruction at the turbine, pump and feed heater is calculated to complete the calculation. Energy estimation result shows that DSRORC determines better net power output and thermal efficiency for 7.9% than SSRORC, as well as exergy estimation, DSRORC determines higher exergy efficiency for 7.69%. ©2019. CBIORE-IJRED. All rights reserved

scholarly journals Thermodynamic Performance Analyses and Optimization of Dual-Loop Organic Rankine Cycles for Internal Combustion Engine Waste Heat Recovery

2019 ◽  
Vol 9 (4) ◽  
pp. 680 ◽  
Author(s):  
Zhong Ge ◽  
Jian Li ◽  
Yuanyuan Duan ◽  
Zhen Yang ◽  
Zhiyong Xie
Keyword(s):  
Power Output ◽  
Combustion Engine ◽  
Working Fluid ◽  
Condensation Temperature ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Evaporation Temperature ◽  
Thermodynamic Performance ◽  
Exhaust Gas Temperature ◽  
Net Power Output

Waste heats of an internal combustion engine (ICE) are recovered by a dual-loop organic Rankine cycle (DORC). Thermodynamic performance analyses and optimizations are conducted with 523.15–623.15 K exhaust gas temperature (Tg1). Cyclopentane, cyclohexane, benzene, and toluene are selected as working fluids for high-temperature loop (HTL), whereas R1234ze(E), R600a, R245fa, and R601a are selected as working fluids for low-temperature loop (LTL). The HTL evaporation temperature, condensation temperature, and superheat degree are optimized through a genetic algorithm, and net power output is selected as the objective function. Influences of Tg1 on system net power output, thermal efficiency, exergy efficiency, HTL evaporation temperature, HTL condensation temperature, HTL superheat degree, exhaust gas temperature at the exit of the HTL evaporator, heat utilization ratio, and exergy destruction rate of the components are analyzed. Results are presented as follows: the net power output is mainly influenced by HTL working fluid. The optimal LTL working fluid is R1234ze(E). The optimal HTL evaporator temperature increases with Tg1 until it reaches the upper limit. The optimal HTL condensation temperature increases initially and later remains unchanged for a cyclopentane system, thus keeping constant for other systems. Saturated cycle is suitable for cyclohexane, benzene, and toluene systems. Superheat cycle improves the net power output for a cyclopentane system when Tg1 is 568.15–623.15 K.

Selection of Working Fluids for Low-Temperature Power Generation Organic Rankine Cycles System

2012 ◽  
Vol 557-559 ◽  
pp. 1509-1513 ◽  
Author(s):  
Zhong He Han ◽  
Yi Da Yu
Keyword(s):  
Low Temperature ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Heat Sources ◽  
Working Fluids ◽  
Cycle System ◽  
Organic Rankine Cycles ◽  
Organic Fluids ◽  
Cycle Efficiency

A Rankine cycle using organic fluids as working fluids, called organic Rankine cycle (ORC), is potentially feasible in recovering low enthalpy containing heat sources. The choices of fluids should meet the requirement of environment, safety, critical pressure and critical temperature etc. Under the proposed working conditions, R600a, R245fa, R236fa, R236ea, R227ea are chosen as the working fluids of the low-temperature Rankine cycle system, then those fluids are investigated and compared from cycle efficiency, work ratio, exergy efficiency, irreversible loss. The results show that R245fa is an available and effective working fluid for low-temperature Rankine cycle.

scholarly journals Thermodynamic Performance Analysis of Solar Based Organic Rankine Cycle Coupled with Thermal Storage for a Semi-Arid Climate

Machines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 88
Author(s):  
Nasser Mohammed A. Almefreji ◽  
Babras Khan ◽  
Man-Hoe Kim
Keyword(s):  
Performance Analysis ◽  
Solar Radiation ◽  
Power Output ◽  
Thermal Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Thermal Storage ◽  
Moderate Temperature ◽  
Thermodynamic Performance ◽  
Net Power Output

This study focuses on the thermodynamic performance analysis of the solar organic Rankine cycle (SORC) that uses solar radiation over a moderate temperature range. A compound parabolic collector (CPC) was adjusted to collect solar radiation because of its long-lasting nature and featured low concentration ratios, which are favorable for moderate temperature applications. A thermal storage tank was fixed to preserve the solar energy and ensure the system’s continuous performance during unfavorable weather. However, water was used as the heat transfer fluid and R245fa was used as the working fluid in this system. The performance in both the hottest and coldest months was analyzed using the average hourly profile in MATLAB using weather data from Riyadh, Saudi Arabia. Variations in the tank temperature during the charging and discharging modes were found. The hourly based thermal efficiency and net power output for both configurations were also compared. The results show that at 17:00, when the cycle was about to shut down, the thermal efficiency was 12.79% and the network output was 16 kW in July, whereas in January, the efficiency was ~12.80% and the net power output was 15.54 kW.

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