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

Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 309
Author(s):  
Jung-Bo Sim ◽  
Se-Jin Yook ◽  
Young Won Kim
Keyword(s):  
Thermal Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Turbine Rotor ◽  
Loss Coefficient ◽  
Tip Clearance ◽  
Working Fluid ◽  
Turbine Generator ◽  
Turbine Efficiency ◽  
Isentropic Efficiency

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.

Optimization of Overcritical Organic Rankine Cycle

2016 ◽  
Vol 831 ◽  
pp. 306-315
Author(s):  
Qing Quan Wang ◽  
Sławomir Smoleń
Keyword(s):  
Numerical Method ◽  
Thermal Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Independent Variables ◽  
Hot Temperature ◽  
Working Fluid Selection ◽  
Two Independent Variables

This paper explores the optimization cases for overcritical Organic Rankine Cycle (ORC) in various situations. First the ORC optimization in terms of working fluid selection is discussed. In this case, thermal efficiencies for 10 different working fluids have been calculated under certain temperature frames and the results are compared. Second, overcritical optimization case in terms of variation of hot temperature and evaporation pressure is presented. In this overcritical ORC case, the influence of evaporation pressure on ORC thermal efficiency is studied by conducting a case study of R234a, and first 1-D freedom optimization case is discussed within the variation of evaporation pressure. 2-D freedom optimization is also considered, in which the two independent variables, hot temperature and evaporation pressure, are both varied within certain boundaries. This study employs numerical method for this 2-D problem and it is also presented in detail in the case study.

scholarly journals Utilization of Indonesia’s Hot Spring Sources for Electricity using Kalina Cycle and Organic Rankine Cycle

2018 ◽  
Vol 31 ◽  
pp. 01002 ◽  
Author(s):  
Grano Prabumukti ◽  
Widodo Wahyu Purwanto
Keyword(s):  
Heat Source ◽  
Thermal Efficiency ◽  
Hot Springs ◽  
Hot Spring ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Power Capacity ◽  
Spring Temperature ◽  
Kalina Cycle

Indonesia posses 40% of the world's geothermal energy sources. The existence of hydrothermal sources is usually characterized by their surface manifestations such as hot springs, geysers and fumarole. Hot spring has a potential to be used as a heat source to generate electricity especially in a rural and isolated area. Hot springs can be converted into electricity by binary thermodynamic cycles such as Kalina cycle and ORC. The aim of this study is to obtain the best performances of cycle configuration and the potential power capacity. Simulation is conducted using UNISIM software with working fluid and its operating condition as the decision variables. The simulation result shows that R1234yf and propene with simple ORC as desired working fluid and cycle configuration. It reaches a maximum thermal efficiency up to 9.6% with a specific turbine inlet pressure. Higher temperature heat source will result a higher thermal efficiency‥ Cycle thermal efficiency varies from 4.7% to 9.6% depends on source of hot spring temperature. Power capacity that can be generated using Indonesia’s hot spring is ranged from 2 kWe to 61.2 kWe. The highest capacity located in Kawah Sirung and the least located in Kaendi.

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 Multi-objective optimization of CuO based organic Rankine cycle operated using R245ca

2019 ◽  
Vol 116 ◽  
pp. 00062 ◽  
Author(s):  
Parth Prajapati ◽  
Vivek Patel
Keyword(s):  
Heat Transfer ◽  
Thermal Efficiency ◽  
Heat Exchangers ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Source Fluid

The present work deals with multi objective optimization of nanofluid based Organic Rankine Cycle (ORC) to utilise waste heat energy. Working fluid considered for the study is R245ca for its good thermodynamic properties and lower Global Warming Potential (GWP) compared to the conventional fluids used in the waste heat recovery system. Heat Transfer Search (HTS) algorithm is used to optimize the objective functions which tends to maximize thermal efficiency and minimize Levelised Energy Cost (LEC). To enhance heat transfer between the working fluid and source fluid, nanoparticles are added to the source fluid. Application of nanofluids in the heat transfer system helps in maximizing recovery of the waste heat in the heat exchangers. Based on the availability and cost, CuO nanoparticles are considered for the study. Effect of Pinch Point Temperature Difference (PPTD) and concentration of nanoparticles in heat exchangers is studied and discussed. Results showed that nanofluids based ORC gives maximum thermal efficiency of 18.50% at LEC of 2.59 $/kWh. Total reduction of 7.11% in LEC can be achieved using nanofluids.

Design and Optimization of a Low Temperature Organic Rankine Cycle and Turbine

2013 ◽  
Author(s):  
Murat Erbas ◽  
Mehmet Alper Sofuoglu ◽  
Atilla Biyikoglu ◽  
Ibrahim Uslan
Keyword(s):  
Low Temperature ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Cycle Performance ◽  
Working Fluid ◽  
Design Criteria ◽  
Design And Optimization ◽  
Turbine Efficiency ◽  
Design Requirements ◽  
R 134A

In this study, low temperature Organic Rankine Cycle (ORC) systems with single and two-stage turbine are proposed for the production of electricity. The refrigerant R-134a is selected as working fluid based on peak temperature of the cycle for solar and geothermal applications. The design criteria of ORC system is introduced and explained in detail. The radial inflow turbine is selected to satisfy the design requirements. The cycle performance is taken as a key point in the design criteria. The system performance map is constructed based on both velocity triangles and approximate efficiency of turbine. The procedures for turbine and cycle design are introduced in detail. The components of cycle and turbine are modeled using baseline correlations via real gas tables and macros created on Excel for the refrigerant, R134a. Finally, the turbine geometry is optimized to attain maximum turbine efficiency via MATLAB optimization toolbox.

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 Analysis of an Improved Two-Stage Organic Rankine Cycle

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2864 ◽  
Author(s):  
Xinyu Li ◽  
Tao Liu ◽  
Lin Chen
Keyword(s):  
Heat Exchange ◽  
Output Power ◽  
Thermal Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Working Fluid ◽  
Outlet Temperature ◽  
Two Stage ◽  
Thermodynamic Performance

In order to improve the two-stage organic Rankine cycle of two heat exchanges of exhaust gas, a two-stage organic Rankine cycle with a regenerator is proposed. Toluene, benzene, cyclohexane and R245fa were selected as the working fluids of the cycle. The thermal efficiency, exergy efficiency and net output power of the cycle were selected as the objective function of the system. The influence of the regenerative performance on the thermodynamic performance of the system was analyzed. The influence of the temperature change of the primary heat exchange outlet on the thermodynamic performance of the system is discussed. The research shows that the regenerator can increase the net power and thermal efficiency of the cycle output. For the selected working fluid, as the efficiency of the regenerator increases, the thermal efficiency of the cycle and the net output power increase. When the primary heat exchange outlet temperature of the exhaust gas increases, the net output power and the exergy efficiency of the cycle increase. For the selected working fluid, when the exhaust heat exchange outlet temperature was increased from 410 K to 490 K, the net output power of the cycle increased up to 10.76 kW, and the exergy efficiency increased up to 7.85%.

Thermodynamic Analysis for Organic Rankine Cycle Recovery System in Industrial Waste Heat

2012 ◽  
Vol 619 ◽  
pp. 310-314
Author(s):  
Xin Le Yang ◽  
Wen Zhi Dai ◽  
Chang Zai Ren
Keyword(s):  
Thermal Efficiency ◽  
Waste Heat ◽  
Thermal Power ◽  
Organic Rankine Cycle ◽  
Industrial Process ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Cement Kiln ◽  
Analysis Model ◽  
Recovery System

For recovering low temperature waste heat from industrial process efficiently, the organic Rankine cycle (ORC) was puts forward to use for thermal power generation. The flue gas parameter of waste heat from a cement kiln was set the research object and ORC system thermal analysis model was established using R123 as working fluid. A calculation program was carried and two main factors were given and the influence rules of thermodynamic performance were analyzed. The results show that the net work of system increases first and then decreased with the evaporating temperature and pressure and a parabolic rule is formed. The maximum net work is 4510kW and corresponding optimum evaporating temperature and optimal evaporating pressure are 140 °C and 1.46MPa respectively; The thermal efficiency increases with evaporating temperature and evaporating pressure increasing. The highest thermal efficiency can reach 12.68%.

Thermodynamic Analysis of Organic Rankine Cycle (ORC) Systems Based on Turbine Performance Prediction

2016 ◽  
Author(s):  
Jian Song ◽  
Chun-wei Gu
Keyword(s):  
System Analysis ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Parameter Determination ◽  
Working Fluid ◽  
Low Grade ◽  
One Dimensional ◽  
Turbine Efficiency ◽  
Turbine Performance ◽  
The One

Energy shortage and environmental deterioration are two crucial issues that the developing world must face. As a promising solution, the conversion of low grade energies is attracting more and more attention. Among all of the existing technologies, Organic Rankine Cycle (ORC) has been proven to be an effective method to utilize the low grade energies. Thermodynamic analysis is important for working fluid selection and system parameter determination in the ORC system. In conventional studies, the efficiency of the organic turbine is fixed at a constant value. However, the turbine efficiency is evidently related to the working fluid property and system operating condition. Thus, the constant turbine efficiency is unreasonable and may lead to sub-optimal thermal results. To enhance the reliability and accuracy of ORC system analysis, the one-dimensional analysis model is used to predict the turbine performance in this paper. The calculated one-dimensional turbine efficiency replaces the constant efficiency in the system analysis. The influence of the working fluid property and system operating condition on the turbine performance is evaluated. Thermal performances of the ORC systems with the one-dimensional turbine efficiency and the constant turbine efficiency are simulated and compared. The results reveal that the turbine efficiency plays a significant role in working fluid selection and system parameter determination for the ORC system.

scholarly journals Working Fluid Selection for Organic Rankine Cycle Using Single-Screw Expander

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3197 ◽  
Author(s):  
Xinxin Zhang ◽  
Yin Zhang ◽  
Min Cao ◽  
Jingfu Wang ◽  
Yuting Wu ◽  
...  
Keyword(s):  
Heat Exchange ◽  
Thermal Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Work Output ◽  
Two Phase ◽  
Single Screw ◽  
Working Fluid Selection ◽  
Selection For

The organic Rankine cycle (ORC) is a popular technology used in waste heat recovery and medium-low-temperature heat utilization. Working fluid plays a very important role in ORC. The selection of working fluid can greatly affect the efficiency, the operation condition, the impact on the environment, and the economic feasibility of ORC. The expander is a key device in ORC. As a novel expander, single-screw expanders have been becoming a research focus in the above two areas because of their many good characteristics. One of the advantages of single-screw configurations is that they can conduct a vapor–liquid two-phase expansion. Therefore, in order to give full play to this advantage, a working fluid selection for ORC using a single-screw expander was conducted in this paper. Three indicators, namely, net work output, thermal efficiency, and heat exchange load of condenser, were used to analyze the performance of an ORC system. Through calculation and analysis, it can be seen that an ORC system that uses a single-screw expander and undergoes a vapor–liquid two-phase expansion is able to obtain a higher thermal efficiency, higher net work output, and a smaller heat exchange load of the condenser. Regardless of whether isentropic efficiency of the expander is considered or not, cis-butene may be the best candidate for working in subcritical cycles. HFO working fluids are more suitable for working in transcritical cycles, and HFO-1234ze(E) may be the best.

Sign in / Sign up

Export Citation Format

Share Document