Energy and Exergy Performance Comparative Analysis of Solar Driven Organic Rankine Cycle Using Different Organic Fluids

2021 ◽  
pp. 1-38
Author(s):  
Md. Tareq Chowdhury ◽  
Esmail M. A. Mokheimer
Keyword(s):  
Energy Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Optimum Operating ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet ◽  
Energy And Exergy ◽  
Organic Fluids

Abstract In this study, the performance of Parabolic Trough Collector (PTC) integrated with Organic Rankine Cycle (ORC) is investigated to find the optimum operating scenarios and to assess the exergy destruction at different components of the system. Commercial PTC LS-2 model with Therminol VP-1 as heat transfer fluid was integrated with an organic Rankine cycle that was examined for its thermal and exergetic performance using different organic fluids. It was found that every fluid has an optimum pressure and temperature level at which it works better than other fluids. R134a (Tetrafluoroethane, CH2FCF3) showed the best performance for the turbine inlet temperature range from 340 K — 440 K regarding the achieved energy and exergy efficiencies. At a temperature of 362.8 K and a pressure of 2750 kPa, R134a showed the highest energy efficiency of 8.55% and exergy efficiency of 21.84% with the lowest mass flow rate required in ORC. Energy efficiency of other fluids namely, R245fa (Pentafluoropropane, CF3CH2CHF2), n-pentane and Toluene were less than 5%. On the other hand, Toluene exhibited thermal efficiency of 23.5 % at turbine inlet temperature of 550 K and pressure of 2500 kPa, while the exergy efficiency was 62.89 % at solar irradiation of 1 kW/m2.

Energy and Exergy Analysis of an Organic Rankine Cycle used for Ylang-Ylang Essential Oil Distillery Waste Heat Recovery for Power Production in Anjouan Island

2021 ◽  
Vol 1 (1) ◽  
pp. 15-24
Author(s):  
Malik El’Houyoun Ahamadi ◽  
Hery T. Rakotondramiarana
Keyword(s):  
Energy Efficiency ◽  
Essential Oil ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Power Production ◽  
Exergy Efficiency ◽  
Inlet Pressure ◽  
Working Fluid ◽  
Energy And Exergy ◽  
Residual Heat

In the ylang-ylang essential oil distillers in Anjouan Island, the used energy is 100% firewood biomass. A large amount of this energy is dissipated in the environment just in the combustion chamber itself. As it turns out, the flue gases in this process take away the most part of it. Thus, in a process of energy efficiency of stills, the present work aims at assessing the possibility to convert the residual heat from the process into electricity. For that purpose, energy and exergy modeling of an organic Rankine cycle was implemented. It was found that a large amount of exergy is destroyed in the evaporator. Similarly, it emerges that the exergy efficiency of the cycle depends on the inlet temperatures of the exhaust gases in the evaporator and on the inlet pressure of the working fluid in the turbine, and that it is much better for low exhaust gas temperatures. At these low values of gas temperatures, it appears that the improvement in exergy efficiency and energy efficiency are linked to the increase in the inlet pressure of the working fluid in the turbine. It follows from the obtained results that the discharged hot water and the residual heat of gases having temperatures ranging from 180°C to 300 °C, could be used for power production which can reach electrical powers between 1.4kW and 4.5kW  

Energy and Exergy Assessments of a New Trigeneration System Based on Organic Rankine Cycle and Biomass Combustor

2010 ◽  
Author(s):  
Fahad A. Al-Sulaiman ◽  
Feridun Hamdullahpur ◽  
Ibrahim Dincer
Keyword(s):  
Electrical Power ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Heating Process ◽  
Inlet Temperature ◽  
Exergy Destruction ◽  
Energy And Exergy ◽  
Pump Inlet ◽  
Exergy Analyses

In this paper, energy and exergy analyses of a trigeneration system based on an organic Rankine cycle (ORC) and a biomass combustor are presented. This trigeneration system consists of a biomass combustor to provide heat input to the ORC, an ORC for power production, a single-effect absorption chiller for cooling process and a heat exchanger for heating process. The system is designed to produce around 500 kW of electricity. In this study, four cases are considered, namely, electrical-power, cooling-cogeneration, heating-cogeneration and trigeneration cases. The effects of changing ORC pump inlet temperature and turbine inlet pressure on different key parameters have been examined to evaluate the performance of the trigeneration system. These parameters are energy and exergy efficiencies, electrical to cooling ratio and electrical to heating ratio. Moreover, exergy destruction analysis is presented to show the main sources of exergy destruction and the contribution of each source to the exergy destruction. The study shows that there are significant improvements in energy and exergy efficiencies when trigeneration is used as compared to electrical power. The results show that the maximum efficiencies for the cases considered in this study are as follows: 14.0% for electrical power, 17.0% for cooling cogeneration, 87.0% for heating cogeneration and 89.0% for trigeneration. On other hand, the maximum exergy efficiency of the ORC is 13.0% while the maximum exergy efficiency of the trigeneration system is 28.0%. In addition, this study reveals that the main sources of exergy destruction are the biomass combustor and ORC evaporator.

scholarly journals Energy and Exergy Efficiency Analysis of Fluid Flow and Heat Transfer in Sinter Vertical Cooler

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4522
Author(s):  
Zude Cheng ◽  
Haitao Wang ◽  
Junsheng Feng ◽  
Yongfang Xia ◽  
Hui Dong
Keyword(s):  
Heat Transfer ◽  
Energy Efficiency ◽  
Fluid Flow ◽  
Waste Heat ◽  
Exergy Efficiency ◽  
Inlet Temperature ◽  
Operational Parameters ◽  
Flow And Heat Transfer ◽  
Maximum Value ◽  
Energy And Exergy

In order to fully understand the energy and exergy transfer processes in sinter vertical coolers, a simulation model of the fluid flow and heat transfer in a vertical cooler was established, and energy and exergy efficiency analyses of the gas–solid heat transfer in a vertical cooler were conducted in detail. Based on the calculation method of the whole working condition, the suitable operational parameters of the vertical cooler were obtained by setting the net exergy efficiency in the vertical cooler as the indicator function. The results show that both the quantity of sinter waste heat recovery (SWHR) and energy efficiency increased as the air flow rate (AFR) increased, and they decreased as the air inlet temperature (AIT) increased. The increase in the sinter inlet temperature (SIT) resulted in an increase in the quantity of SWHR and a decrease in energy efficiency. The air net exergy had the maximum value as the AFR increased, and it only increased monotonically as the SIT and AIT increased. The net exergy efficiency reached the maximum value as the AFR and AIT increased, and the increase in the SIT only resulted in a decrease in the net exergy efficiency. When the sinter annual production of a 360 m2 sintering machine was taken as the processing capacity of the vertical cooler, the suitable operational parameters of the vertical cooler were 190 kg/s for the AFR, and 353 K for the AIT.

Thermodynamic analysis of a wall mounted gas boiler with an organic Rankine cycle and hydrogen production unit

2017 ◽  
Vol 28 (7) ◽  
pp. 725-743 ◽  
Author(s):  
Anahita Moharamian ◽  
Saeed Soltani ◽  
Faramarz Ranjbar ◽  
Mortaza Yari ◽  
Marc A Rosen
Keyword(s):  
Hydrogen Production ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Inlet Pressure ◽  
Pinch Point ◽  
Working Fluids ◽  
Turbine Inlet ◽  
Energy And Exergy ◽  
Cogeneration System ◽  
Net Power Output

A novel cogeneration system based on a wall mounted gas boiler and an organic Rankine cycle with a hydrogen production unit is proposed and assessed based on energy and exergy analyses. The system is proposed in order to have cogenerational functionality and assessed for the first time. A theoretical research approach is used. The results indicate that the most appropriate organic working fluids for the organic Rankine cycle are HFE700 and isopentane. Utilizing these working fluids increases the energy efficiency of the integrated wall mounted gas boiler and organic Rankine cycle system by about 1% and the organic Rankine cycle net power output about 0.238 kW compared to when the systems are separate. Furthermore, increasing the turbine inlet pressure causes the net power output, the organic Rankine cycle energy and exergy efficiencies, and the cogeneration system exergy efficiency to rise. The organic Rankine cycle turbine inlet pressure has a negligible effect on the organic Rankine cycle mass flow rate. Increasing the pinch point temperature decreases the organic Rankine cycle turbine net output power. Finally, increasing the turbine inlet pressure causes the hydrogen production rate to increase; the highest and lowest hydrogen production rates are observed for the working fluids for HFE7000 and isobutane, respectively. Increasing the pinch point temperature decreases the hydrogen production rate. In the cogeneration system, the highest exergy destruction rate is exhibited by the wall mounted gas boiler, followed by the organic Rankine cycle evaporator, the organic Rankine cycle turbine, the organic Rankine cycle condenser, the proton exchange membrane electrolyzer, and the organic Rankine cycle pump, respectively.

Thermodynamic and Economic Analysis and Multi-Objective Optimization of Supercritical CO2 Brayton Cycles

2015 ◽  
Author(s):  
Hang Zhao ◽  
Qinghua Deng ◽  
Wenting Huang ◽  
Zhenping Feng
Keyword(s):  
Supercritical Co2 ◽  
Exergy Efficiency ◽  
Temperature Cycle ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Multi Objective Optimization ◽  
Turbine Inlet Temperature ◽  
Multi Objective ◽  
Turbine Inlet ◽  
Thermodynamic Performance

Supercritical CO2 Brayton cycles (SCO2BC) offer the potential of better economy and higher practicability due to their high power conversion efficiency, moderate turbine inlet temperature, compact size as compared with some traditional working fluids cycles. In this paper, the SCO2BC including the SCO2 single-recuperated Brayton cycle (RBC) and recompression recuperated Brayton cycle (RRBC) are considered, and flexible thermodynamic and economic modeling methodologies are presented. The influences of the key cycle parameters on thermodynamic performance of SCO2BC are studied, and the comparative analyses on RBC and RRBC are conducted. Based on the thermodynamic and economic models and the given conditions, the Non-dominated Sorting Genetic Algorithm II (NSGA-II) is used for the Pareto-based multi-objective optimization of the RRBC, with the maximum exergy efficiency and the lowest cost per power ($/kW) as its objectives. In addition, the Artificial Neural Network (ANN) is chosen to establish the relationship between the input, output, and the key cycle parameters, which could accelerate the parameters query process. It is observed in the thermodynamic analysis process that the cycle parameters such as heat source temperature, turbine inlet temperature, cycle pressure ratio, and pinch temperature difference of heat exchangers have significant effects on the cycle exergy efficiency. And the exergy destruction of heat exchanger is the main reason why the exergy efficiency of RRBC is higher than that of RBC under the same cycle conditions. Compared with the two kinds of SCO2BC, RBC has a cost advantage from economic perspective, while RRBC has a much better thermodynamic performance, and could rectify the temperature pinching problem that exists in RBC. Therefore, RRBC is recommended in this paper. Furthermore, the Pareto front curve between the cycle cost/ cycle power (CWR) and the cycle exergy efficiency is obtained by multi-objective optimization, which indicates that there is a conflicting relation between them. The optimization results could provide an optimum trade-off curve enabling cycle designers to choose their desired combination between the efficiency and cost. Moreover, the optimum thermodynamic parameters of RRBC can be predicted with good accuracy using ANN, which could help the users to find the SCO2BC parameters fast and accurately.

scholarly journals Exergy Efficiency Optimization for Gas Turbine Based Cogeneration Systems

2013 ◽  
Author(s):  
Ana C. Ferreira ◽  
Senhorinha F. Teixeira ◽  
José C. Teixeira ◽  
Manuel L. Nunes ◽  
Luís B. Martins
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Exergy Analysis ◽  
Exergy Efficiency ◽  
Plant Performance ◽  
System Component ◽  
Inlet Temperature ◽  
Exergy Destruction ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet

Energy degradation can be calculated by the quantification of entropy and loss of work and is a common approach in power plant performance analysis. Information about the location, amount and sources of system deficiencies are determined by the exergy analysis, which quantifies the exergy destruction. Micro-gas turbines are prime movers that are ideally suited for cogeneration applications due to their flexibility in providing stable and reliable power. This paper presents an exergy analysis by means of a numerical simulation of a regenerative micro-gas turbine for cogeneration applications. The main objective is to study the best configuration of each system component, considering the minimization of the system irreversibilities. Each component of the system was evaluated considering the quantitative exergy balance. Subsequently the optimization procedure was applied to the mathematical model that describes the full system. The rate of irreversibility, efficiency and flaws are highlighted for each system component and for the whole system. The effect of turbine inlet temperature change on plant exergy destruction was also evaluated. The results disclose that considerable exergy destruction occurs in the combustion chamber. Also, it was revealed that the exergy efficiency is expressively dependent on the changes of the turbine inlet temperature and increases with the latter.

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

Optimizing Energy Conversion Using Organic Rankine Cycles and Supercritical Rankine Cycles

2011 ◽  
Author(s):  
Huijuan Chen ◽  
D. Yogi Goswami ◽  
Muhammad M. Rahman ◽  
Elias K. Stefanakos
Keyword(s):  
Energy Conversion ◽  
Cooling Water ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Working Fluid ◽  
Condensation Process ◽  
Inlet Temperature ◽  
Low Grade ◽  
Energy Conversion Systems

The optimization of energy conversion systems is of great significance in the utilization of low-grade heat. This paper presents an analysis of 6 working fluids in 12 thermodynamic cycles to optimize the energy conversion systems. The optimal exergy efficiency of the system is dependent on the type of the thermodynamic cycle, the choice of appropriate working fluid, and the working conditions. A zeotropic mixture of R134a and R245fa shows advantages in energy conversion process, as well as its heat exchange with the heat source and heat sink. The exergy efficiency of a 0.5R134a/0.5R245fa-based supercritical Rankine cycle system is 0.643–0.689 for a turbine inlet temperature of 415–445K, which is about 30% improvement over the exergy efficiency of 0.491–0.521 for a pure R32-based organic Rankine cycle under the same temperature limits. Furthermore, the 0.5R134a/0.5R245fa mixture saves more than 60% of the cooling water during the condensation process than the pure R32, R134a and R245fa.

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