Analysis Of Organic Rankine Cycle Research Articles

Theoretical analysis of organic Rankine cycle for maximum power generation in optimization operation conditions

The global critical issue in energy scarcity should be appropriately solved to realize a sustainable society. Effective use of Rankine cycle is one possible way since it provides most of worldwide electricity production. In this paper, theoretical analysis model of organic working fluids R717, R134a, R1234yf, R290, R245fa and R1233zd in Rankine cycle for maximum power generation in optimization operation using low-temperature heat sources are proposed and studied for development next generation green and zero-carbon energy generation system to promote the race to zero. Results show that temperatures of warm and cold water at inlet, mass flow rate of the warm water and performance of the evaporator play a key role to obtain the theoretical optimization operation conditions for maximum power generation. In the case of same initial conditions of temperatures of warm water (85 Celsius degree) and cold water (15 Celsius degree) at inlet, mass flow rate of the warm water (10kg/s) and performance of the evaporator (100kW/K), R717 has the best performance in terms of the maximum power output 56.0kW with thermal efficiency of 8.6%, and the next is the R1233zd (54.4kW, 8.3%), R245fa (54.0kW, 8.2%), R134a (52.8kW, 7.9%), R290 (52.7kW, 7.9%), and R1234yf (51.7kW, 7.7%). Here, it should be noticed that other optimization conditions are almost the same (mass flow rate of the cold water 9.1∼9.2kg/s; performance of the condenser 91∼92kW/K) to get their maximum power output of ORC. In addition, it also known that low-GWP R1233zd (GWP: 1) can deserve the best option to replace R245fa (GWP: 950) and R1234yf (GWP: 4) also can replace r134a (GWP: 1430) since their optimization operation conditions are almost same.

Thermoeconomic analysis of organic Rankine cycle with different working fluids for waste heat recovery from a coal-based thermal power plant

Thermoeconomic analysis of organic Rankine cycle with different working fluids for waste heat recovery from a coal-based thermal power plant

Thermo-economic analysis of organic Rankine cycle using a new two-stage solar collector with nanofluids

The flat plate collector (FPC) has a low economic cost, while the parabolic trough collector (PTC) has a high heat collection temperature. To reduce costs, improve efficiency, and promote the use of solar energy, this study proposes a new two-stage solar collector that couples FPC and PTC. The main objective of this paper is to verify the performance of this two-stage solar collector when containing nanofluids. This collector drives the organic Rankine cycle (ORC) with four nanoparticles (Cu, CuO, TiO2, and Al2O3) in the oil heat transfer fluid. The FPC outlet temperature in the two-stage solar collector is optimized, the exergy of ORC is analyzed, and the economics of the new system using nanofluid are calculated and compared with those of the new system without nanofluid. Results show that Cu-oil outperforms the other nanofluids in terms of heat transfer. At a rated output power of 5 kW, the new two-stage solar collector with 5 % Cu-oil can reduce economic costs by 6.8 % compared with a single PTC. Meanwhile, the ORC with a two-stage solar collector using 5 % Cu-oil reduces the economic costs by 5.7 % compared with the ORC equipped with PTC without nanofluid. The new system has a minimum payback period of 17.3 years, and increasing the output power of the ORC is beneficial for reducing the investment payback period of the system.

Thermo-Economic Analysis of Organic Rankine Cycle with Different Working Fluids for Waste Heat Recovery from Coal-based Power Plant

The utilization of waste heat from power plants, which is generally lost to the atmosphere, can reduce energy waste significantly. Heat recovery systems can be integrated with power plants to utilize the waste heat, improving plant energy efficiency and reducing fossil fuel consumption and carbon emissions. The current study is focused on harnessing waste heat through the Organic Rankine Cycle (ORC) from 500 MWe supercritical power plant with CO2 capture. The simulation flow sheet program “Cycle-Tempo” models and simulates different plant layouts. This study considered five different working fluids for ORC, such as R245fa, Benzene, Methanol, Ethanol, and Acetone. The ORC generates additional electricity of 9.91 MWe for R245fa, 14.11 MWe for Benzene, 13.71 MWe for Methanol, 14.04 MWe for Ethanol and 13.97 MWe for Acetone. The thermodynamic study concludes that ORC based on benzene is the best, and the economic analysis discloses that ORC based on ethanol is the best among all working fluids with a payback period of 0.869 years and cost of electricity of Rupees 1.101 per kWh. This study also concludes that the novel technique used in the present study is economically viable, contributing to a more energy-efficient and environmentally friendly power generation system.

Exergy and energy analysis of Organic Rankine Cycle integration in the carbon black industry using pinch technology

Industrial Carbon black production is a petrochemical process that has high level of waste heat and emissions. Main points of CB process include furnace and stack lines. Also, the use of different feedstocks can be effective in level of waste heat and amount of emission pollutants. So the main objective of this research use from the pinch technology in CB process in order to minimize the level of waste heat by utilization of waste heat recovery (WHR) applications for power generation. By numerical investigation and modelling of WHR in furnace and stack points, can be defined best location for power generation in CB process. Moreover, through the analysis of Organic Rankine Cycle (ORC) systems integrated with WHR from both energy and exergy perspectives, second target to enhance their thermal efficiency. The results indicate that the presence of blowers on stacks leads to an increase in RoHR and RoHC. In order to determine the optimal location for power generation cycle installation, an ORC energy and exergy analysis was conducted. The results showed that the energy and exergy values at the SLC stack were higher than those at the HLC point. Also, numerical results showed the points that have suitable thermal efficiency and rate of exergy of WHR where have higher temperature gradient than other points. So SLC (ĖxWHR=166.7kW) and HLC (ĖxWHR=136.1kW) stacks integrated with blower are the optimal location for WHR utilization in the CB production process.

Thermodynamic and economic analysis of organic Rankine cycle combined with flash cycle and ejector

Increasing the net output power of the Organic Rankine Cycle (ORC) can increase the possibility of developing low-medium temperature heat sources. It is equally important to effectively control the system's economy. So, subcritical double-pressure ORC combined with flash cycle and ejector (S-EFDPORC) and transcritical ORC combined with flash cycle and ejector (T-EFDPORC) are proposed in present work. The thermodynamic and economic analyses on five proposed systems within the heat source temperature range of 100 °C–200 °C are conducted. The net output power and levelized energy cost (LEC) are treated as optimization objectives in thermodynamic and economic performance comparisons, respectively. The non-dominated sorting and three multi-objective optimization methods (LINMAP, TOPSIS, and Shannon Entropy) are used to perform the multi-objective optimization. The results show that S-EFDPORC and T-EFDPORC can both effectively improve the net output power compared with subcritical double-pressure ORC (S-DPORC) and transcritical double-pressure ORC (T-DPORC), while subcritical ORC combined with flash cycle and ejector (S-EFORC) can only improve the net output power within a certain temperature range. When the optimization objective is the net output power, compared with S-DPORC and T-DPORC, the growth rate of net output power in S-EFORC is more than 20% when the temperature is below 160 °C. When the temperature of the heat source is below 160 °C or above 180 °C, the growth rates of net output power of S-EFDPORC and T-EFDPORC increase more than 25%. When LEC is treated as optimization objective, compared with S-DPORC and T-DPORC, S-EFORC reduces LEC by more than 10%. S-EFDPORC and T-EFDPORC increase the LEC of the system, and the maximum growth rates of LEC are 30% and 60% respectively, resulting in worse economic performance. With three multi-objective optimization methods, both S-EFDPORC and T-EFDPORC can increase net output power, but their economy will deteriorate at most heat source temperatures. Although S-EFORC increase the net output power when the heat source temperature is below than 177 °C, LEC reduces throughout the heat source temperature range.

Performance Analysis of Organic Rankine Cycle with Internal Heat Regeneration: Comparative Study of Binary Mixtures and Pure Constituents in Warm Regions

There are various organic compounds that can be utilized in the organic Rankine cycle as working fluids. The selection of a suitable working fluid is complicated due to the large number of options and factors affecting the choice, such as thermodynamic properties, environmental impact, cost, etc. This study evaluates seven different pure organic compounds and twenty-one of their binary zeotropic mixtures as potential working fluids for the organic Rankine cycle powered by a heat source at 200 °C. The pure organic fluids show higher exergy efficiency, higher specific net power output, and lower heat exchange area requirements compared to the binary mixtures. Among the pure fluids, RE347mcc performs the best in terms of exergy efficiency, followed by neopentane, isopentane, and pentane. Cyclopentane exhibits the highest power production capacity per unit mass flow rate of the working fluid. Two mixtures, pentane/Novec 649 and cyclopentane/Novec 649, showed significantly higher exergy efficiency than their individual components, but at significantly lower specific power production capacity. The study presents an interesting trade-off between exergy efficiency and heat exchange area, indicating that a small increase in exergy efficiency can lead to a large decrease in the required heat exchange area. The outcomes of this study can help in selecting suitable working fluids for ORC operation with a heat source at 200 °C.

Optimization analysis of Organic Rankine Cycle powered by waste heat of a supermarket transcritical CO2 multi-ejector refrigeration cycle

The exploitation of low-grade heat sources that are available from existing thermal systems processes consists a promising concept for the production of energy. In this research, the integration of an Organic Rankine Cycle (ORC) unit on a supermarket transcritical CO2 refrigeration system with ejectors is investigated, which is supplied with low-grade heat by the common discharge of the compressors. The optimization analysis proves that for different combinations of CO2 temperature and pressure in the ORC evaporator, as well as for different ORC condensation temperatures, there is a different optimum ORC evaporation temperature that leads to the highest energy production. Concerning the annual performance analysis conducted for the city of Athens, Greece, operation with isopentane is found to provide the greatest energy production with 10.36 MWh annually, which corresponds to a 3.69% reduction in the refrigeration system's energy consumption. For operation under the ambient temperature of 40 °C, the corresponding reduction of the refrigeration system consumption due to the presence of ORC is 7.54%. Finally, the financial analysis reveals that toluene is the most advantageous solution, leading to a payback period of 3.9 years, with a net present value by the end of the project's lifetime equal to 34.32 k€.

Design of the Organic Rankine Cycle for High-Efficiency Diesel Engines in Marine Applications

Over the past few years, fuel prices have increased dramatically, and emissions regulations have become stricter in maritime applications. In order to take these factors into consideration, improvements in fuel consumption have become a mandatory factor and a main task of research and development departments in this area. Internal combustion engines (ICEs) can exploit only about 15–40% of chemical energy to produce work effectively, while most of the fuel energy is wasted through exhaust gases and coolant. Although there is a significant amount of wasted energy in thermal processes, the quality of that energy is low owing to its low temperature and provides limited potential for power generation consequently. Waste heat recovery (WHR) systems take advantage of the available waste heat for producing power by utilizing heat energy lost to the surroundings at no additional fuel costs. Among all available waste heat sources in the engine, exhaust gas is the most potent candidate for WHR due to its high level of exergy. Regarding WHR technologies, the well-known Rankine cycles are considered the most promising candidate for improving ICE thermal efficiency. This study is carried out for a six-cylinder marine diesel engine model operating with a WHR organic Rankine cycle (ORC) model that utilizes engine exhaust energy as input. Using expander inlet conditions in the ORC model, preliminary turbine design characteristics are calculated. For this mean-line model, a MATLAB code has been developed. In off-design expander analysis, performance maps are created for different speed and pressure ratios. Results are produced by integrating the polynomial correlations between all of these parameters into the ORC model. ORC efficiency varies in design and off-design conditions which are due to changes in expander input conditions and, consequently, net power output. In this study, ORC efficiency varies from a minimum of 6% to a maximum of 12.7%. ORC efficiency performance is also affected by certain variables such as the coolant flow rate, heat exchanger’s performance etc. It is calculated that with the increase of coolant flow rate, ORC efficiency increases due to the higher turbine work output that is made possible, and the condensing pressure decreases. It is calculated that ORC can improve engine Brake Specific Fuel Consumption (BSFC) from a minimum of 2.9% to a maximum of 5.1%, corresponding to different engine operating points. Thus, decreasing overall fuel consumption shows a positive effect on engine performance. It can also increase engine power output by up to 5.42% if so required for applications where this may be deemed necessary and where an appropriate mechanical connection is made between the engine shaft and the expander shaft. The ORC analysis uses a bespoke expander design methodology and couples it to an ORC design architecture method to provide an important methodology for high-efficiency marine diesel engine systems that can extend well beyond the marine sector and into the broader ORC WHR field and are applicable to many industries (as detailed in the Introduction section of this paper).

Improve Waste Heat Recovery and Performance of Organic Rankine Cycle Analysis for Exhaust Gas from A Marine Diesel Engine Using Biofuel from Algae

Marine diesel engines are commonly used as a propulsion system in ships. The waste heat generated from marine diesel engines is one of the key disadvantages of this system. This study aims to improve the recovery of waste heat generation. It presents the performance analysis of Organic Rankine Cycle (ORC) for exhaust gas in a marine diesel engine using different types of biofuels production methods from selected microalgae via mathematical modelling. The microalgae are from species of Synechococcus PCC 7002, Nannochloropsis oculata sp, Chlorella protothecoides, and Dunaliella sp. A marine engine with an exhaust gas of 9086.61 kg-h-1 is taken as a case study. While the conventional diesel engine has a performance efficiency of 30-40% with a power output of 35-200K, this study has indicated that the marine diesel engine in the ORC via biofuel from algae shows higher performance at approximately 51% with a net power output of approximately 160kW obtained for each biofuel. Later, the thermal efficiency of the ORC system with exhaust gas from the marine diesel engine as waste heat recovery is improved to 61% with a net power output of approximately 353kW after the heat integration. Biodiesel presents the highest mass flow rate (1.12 kg-s-1) compared to others. This study proved that biofuel from microalgae can achieve the highest performance in the ORC system with the lowest mass flow rate of biofuel compared to those in conventional fuel.

Exergy Analysis of Organic Rankine Cycles with Zeotropic Working Fluids

Waste heat recovery is one of the possible solutions to improve the efficiency of internal combustion engines. Instead of wasting the exhaust stream of an energy conversion system into the environment, its residual energy content can be usefully recovered, for example in Organic Rankine Cycles (ORC). This technology has been largely consolidated in stationary power plants but not yet for mobile applications, such as road transport, due to the limitations in the layout and to the constraints on the size and weight of the ORC system. An ORC system installed on the exhaust line of a bus powered by a natural gas spark ignition engine has been investigated. The thermal power available at engine exhaust has been evaluated by measuring gas temperature and mass flow rate during real driving operation. The waste thermal power has been considered as heat input for the ORC plant simulation. A detailed heat exchanger model has been developed because it is a crucial component for the ORC performance. The exergy analysis of the ORC was performed comparing different working fluids: R601, R1233zd(E) and two zeotropic blends of the two organic pure fluids. The model allowed the evaluation of the ORC produced energy over the driving cycle and the potential benefit on the engine efficiency.

Nonlinear modeling and multi-scale influence characteristics analysis of organic Rankine cycle (ORC) system considering variable driving cycles

The reasonable construction of the organic Rankine cycle (ORC) system model under road conditions is the key to analyze, evaluate, and optimize the performance of the ORC system. However, due to the variability of high-temperature waste heat source and the strong coupling correlation of operating parameters, the operation characteristics of the ORC system show evident time-varying characteristics. Based on the coupling correlation and redundancy characteristics of the ORC system in complex environment, this paper presents a nonlinear modeling framework for the multi-scale influence analysis of the ORC system under road conditions. The nonlinear modeling framework can improve the prediction accuracy of ORC model by at least 68.36% and reduce the time cost by 53.37%. Based on the nonlinear model, the synergistic effects of multiple variables on ORC system performance at different scales are studied. The frequent fluctuation of vehicle speed enhances the coupling correlation of operating parameters, resulting in nonlinear, hysteretic dynamic characteristics of ORC thermal efficiency. The maximum thermal efficiency of ORC is only 3.28%. The nonlinear modeling framework proposed in this paper can provide a practical solution for constructing the intelligent analysis, design, and optimization models of ORC systems under complex road conditions.

Comparative analysis of organic rankine cycle, Kalina cycle and thermoelectric generator to recover waste heat based on energy, exergy, economic and environmental analysis method

Recovering waste heat below 100 °C, accounting for 60 % of the whole waste heat, the Organic Rankine cycle (ORC), Kalina cycle (KC) and thermoelectric generator (TEG) are the most promising way, while the adaptive temperature for three systems has not been clearly defined and the thermodynamic, economic and environmental effects of these three systems have not been compared and evaluated. This paper employed the energy, exergy, economic and life cycle climate performance method to analyze the comprehensive performance of three systems for the low-temperature below 100 °C and medium-temperature within 100–200 °C. The adaptive temperature of ORC, KC and TEG are 130–200 °C, 100–130 °C and 50–100 °C. The thermal and exergy efficiency of ORC and KC exhibits 2.7–36.0 % higher than that of TEG when heat source exceeds 100 °C. The cost of electricity production of TEG is around 1–148 times larger than that of ORC and KC (greater than80 °C), while the equivalent CO2 emission of TEG is 2–590 times smaller than that of KC and ORC (50–200 °C). TEG prefers to recover the heat source with low flow rate and low temperature and is a valuable method to recover heat source below 100 °C in future.

Exergy analysis of organic Rankine cycle for waste heat recovery using low GWP refrigerants

The use of exergy analysis in thermodynamic systems, as well as energy analysis, is quickly increasing. Exergy analysis is useful for identifying processes that cause exergy destruction and losses, and it may be used in conjunction with energy analysis. Due to environmental concerns, the use of waste heat has received a lot of attention in recent years. The Organic Rankine Cycle (ORC) is a promising method for converting waste heat into usable work at low temperatures. In this research, both the Basic Organic Rankine Cycle and the Regenerative Organic Rankine Cycle are considered for the analysis. Python is used for the simulation process. This investigation shows that the regenerative ORC has higher thermal and second law efficiency and a lower exergy destruction rate compared to the basic ORC. The Global Warming Potential (GWP) and Ozone Depletion Potential (ODP) of R1233zd(E), R1234ze(Z), R1234ze(E), and R1234yf are considered low. R1233zd(E) had a 1-5.66% and a maximum of 4.17% lower second law efficiency than R113 in regenerative ORC and basic ORC, respectively. On the other hand, R113 is not an eco-friendly fluid. As a result, R1233zd(E) can be used in place of R113 to assure better environmental quality by sacrificing a small portion of efficiency. The fluids which have a higher critical temperature showed better results compared to the fluids which have a lower critical temperature. Throughout the study, R1233zd(E) performed better than the rest of the three fluids. In both basic and regenerative ORC, R1233zd(E) has higher thermal and second law efficiency.

Analysis of organic rankine cycle powered by N-number of solar collectors in series

ABSTRACT Thermodynamic model of the solar power organic Rankine cycle (ORC) has been proposed in the present study. Model is developed in MATLAB 2018a for Cyclohexane/R123 mixture-based ORC system driven by series of N-collectors. Four different collector models namely: Case-I, “N series connection of photovoltaic thermal conventional compound parabolic (NPVTCCPC) collector system”; “Case-II: N series connection of photovoltaic thermal (NPVT) collector system”; “Case-III: N series connection of conventional compound parabolic collector (NCCPC) system”; Case-IV N series connection of flat plate collector (NFPC) system” have been integrated with ORC system. Overall thermal performance has been evaluated for each case and compared individually. Case-III (NCCPC) emerged as the best combination in the view of highest collector exit temperature 110°C, heat gain 255 kW, thermal efficiency 14.14%, exergetic efficiency 54.77%. Further, highest percentage of total exergy destruction was observed in evaporator (37–45%) followed by condenser (28–31%), expander (24–30%) and lowest in pump (1–2%). The present developed system could be a promising solution to power crises in remote and off-grid-connected areas.

Energy and parametric analysis of Organic Rankine Cycle combined with a vapor compression refrigeration cycle (ORC-VCR) system using natural refrigerants

The dependency on fossil fuels for power generation can be reduced by enhancing the energy efficiency of power generating systems. The refrigeration systems that typically use electricity consume a significant portion of the electricity supplied to cities. The STAND-ALONE refrigeration system which consists of a combined Organic Rankine Cycle and Vapor Compression (ORC-VCR) system is analyzed using the first law of thermodynamics. Dry natural hydrocarbons such as n-Dodecane is used as the working fluid in Organic Rankine Cycle (ORC) and natural Working fluid such as isobutane (R600a) is utilized in Vapor Compression Refrigeration (VCR) Cycle. The study shows that the system can be driven efficiently with Low-grade waste heat from industries or thermal energy from renewable energy sources typically in the range from 1000C to 3500C thus reducing reliance on fossil fuel sources. The results also show that the overall Coefficient of performance COP overall of the system and the energy efficiency of the ORC was greatly affected by the evaporation temperature of ORC, Teva_ORC followed by, the evaporation temperature of VCR, Teva_VCR. The maximum COP overall of the system was found to be 0.558 and the energy efficiency of ORC was found to be 20.69% for Teva_ORC of 3150C and Teva_VCR of -300C.

Performance Analysis of Organic Rankine Cycle with the Turbine Embedded in a Generator (TEG)

The organic Rankine cycle (ORC) is a thermodynamic cycle in which electrical power is generated using an organic refrigerant as a working fluid at low temperatures with low-grade enthalpy. We propose a turbine embedded in a generator (TEG), wherein the turbine rotor is embedded inside the generator rotor, thus simplifying turbine generator structure using only one bearing. The absence of tip clearance between the turbine rotor blade and casing wall in the TEG eliminates tip clearance loss, enhancing turbine efficiency. A single-stage axial-flow turbine was designed using mean-line analysis based on physical properties, and we conducted a parametric study of turbine performance, and predicted turbine efficiency and power using the tip clearance loss coefficient. When the tip clearance loss coefficient was applied, turbine isentropic efficiency and power were 0.89 and 20.42 kW, respectively, and ORC thermal efficiency was 4.81%. Conversely, the isentropic efficiency and power of the turbine without the tip clearance loss coefficient were 0.94 and 22.03 kW, respectively, and the thermal efficiency of the ORC was 5.08%. Therefore, applying the proposed TEG to the ORC system simplifies the turbine generator, while improving ORC thermal efficiency. A 3D turbine generator assembly with proposed TEG structure was also proposed.

Comparative Analysis of Organic Rankine Cycle, Kalina Cycle and Thermoelectric Generator to Recover Waste Heat Based on Energy, Economic and Environmental Analysis Method

Comparative Analysis of Organic Rankine Cycle, Kalina Cycle and Thermoelectric Generator to Recover Waste Heat Based on Energy, Economic and Environmental Analysis Method

Energy and economic analysis of organic Rankine cycle for liquid desiccant system

The main purpose of this study is to experimentally evaluate the energy and economic benefits of an organic Rankine cycle (ORC) based liquid desiccant (LD) assisted air conditioning system (ORCLD) for building applications. A district heating network was used as the heat source of the ORC, and the heat and power generated from the ORC was provided for the LD-assisted air conditioning system and building. The primary energy consumption, payback period, and life cycle cost of ORCLD were analyzed and compared with those of the LD-assisted air conditioning system as a reference system. There were two operation modes for ORCLD: power and heat priorities, which obtain the maximum power and heat output, respectively. As a result, the ORCLD with heat priority mode could save the primary energy consumption by 2.2% compared with the reference system and show the lowest payback period and life cycle cost. Consequently, the heat priority mode for the ORCLD is strongly recommended in terms of both energy and cost.

Application Analysis of Organic Rankine Cycle in Low Temperature Waste Heat Utilization

Application Analysis of Organic Rankine Cycle in Low Temperature Waste Heat Utilization