scholarly journals Investigation of an Innovative Cascade Cycle Combining a Trilateral Cycle and an Organic Rankine Cycle (TLC-ORC) for Industry or Transport Application

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3032 ◽  
Author(s):  
Xiaoli Yu ◽  
Zhi Li ◽  
Yiji Lu ◽  
Rui Huang ◽  
Anthony Roskilly
Keyword(s):  
High Temperature ◽  
System Performance ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Working Fluid ◽  
Second Law ◽  
Exergy Destruction ◽  
Second Law Analysis ◽  
Net Power Output

An innovative cascade cycle combining a trilateral cycle and an organic Rankine cycle (TLC-ORC) system is proposed in this paper. The proposed TLC-ORC system aims at obtaining better performance of temperature matching between working fluid and heat source, leading to better overall system performance than that of the conventional dual-loop ORC system. The proposed cascade cycle adopts TLC to replace the High-Temperature (HT) cycle of the conventional dual-loop ORC system. The comprehensive comparisons between the conventional dual-loop ORC and the proposed TLC-ORC system have been conducted using the first and second law analysis. Effects of evaporating temperature for HT and Low-Temperature (LT) cycle, as well as different HT and LT working fluids, are systematically investigated. The comparisons of exergy destruction and exergy efficiency of each component in the two systems have been studied. Results illustrate that the maximum net power output, thermal efficiency, and exergy efficiency of a conventional dual-loop ORC are 8.8 kW, 18.7%, and 50.0%, respectively, obtained by the system using cyclohexane as HT working fluid at THT,evap = 470 K and TLT,evap = 343 K. While for the TLC-ORC, the corresponding values are 11.8 kW, 25.0%, and 65.6%, obtained by the system using toluene as a HT working fluid at THT,evap = 470 K and TLT,evap = 343 K, which are 34.1%, 33.7%, and 31.2% higher than that of a conventional dual-loop ORC.

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

Second Law Analysis and Optimization of Organic Rankine Cycle

2006 ◽  
Author(s):  
C. Somayaji ◽  
P. J. Mago ◽  
L. M. Chamra
Keyword(s):  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Working Fluid ◽  
Second Law ◽  
Low Grade ◽  
Heat Sources ◽  
Working Fluids ◽  
Second Law Analysis

This paper presents a second law analysis and optimization for the use of Organic Rankine Cycle “ORC” to convert waste energy to power from low grade heat sources. The working fluids used in this study are organic substances which have a low boiling point and a low latent heat for using low grade waste heat sources. The organic working fluids under investigation are R134a and R113 and their results are compared with those of ammonia and water under similar operating conditions. A combined first and second law analysis is performed by varying some system operating parameters at various reference temperatures. Some of the results show that the efficiency of ORC is typically below 20% depending on the temperatures and matched working fluid. In addition, it has been found that organic working fluids are more suited for heat recovery than water for low temperature applications, which justifies the use of organic working fluids at the lower waste source temperatures.

Second Law Analysis of Evaporator for Organic Rankine Cycle System

2008 ◽  
Author(s):  
Wei Gu ◽  
Yiwu Weng
Keyword(s):  
Entropy Generation ◽  
Temperature Difference ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Second Law ◽  
Fluid Temperature ◽  
Working Fluids ◽  
Second Law Analysis

The evaporator is a key component for Organic Rankine Cycle (ORC) system. Second law analysis of the evaporator was carried out in this work. Three processes were included and studied: pre-heating, boiling and super-heating. Firstly, ε–NTU method was applied to study the heat transfer area of evaporator. Then, internal entropy generation for three processes of evaporator was studied by entropy generation number. Thirdly, entropy generation distribution (ds/dA) was predicted by analyzing the temperature difference between the two sides of single stage counter-flow evaporator, for both pure and mixed working fluids. The results show that increase of waste heat fluid temperature increases internal irreversibility, and higher evaporator pressure decreases this irreversibility. The results also show that temperature difference at the end part of boiling process is larger for pure working fluids; and for mixed fluids, because of its’ increasing boiling temperature, this irreversibility decreases remarkably. In conclusion, second law analysis shows that the evaporating pressure plays a key role in evaporator design for ORC system; and both evaporator and working fluid should be well designed to minimize the second law loss.

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 A Hot Water Split-Flow Dual-Pressure Strategy to Improve System Performance for Organic Rankine Cycle

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3345 ◽  
Author(s):  
Shiqi Wang ◽  
Zhongyuan Yuan
Keyword(s):  
Output Power ◽  
Thermal Energy ◽  
System Performance ◽  
Industrial Waste ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Hot Water ◽  
Inlet Temperature ◽  
Split Flow ◽  
Net Power Output

The organic Rankine cycle (ORC) is widely used to recover industrial waste heat. For an ORC system using industrial waste hot water as a heat source, a novel hot water split-flow dual-pressure organic Rankine cycle (SFD-ORC) system is developed to improve the performance of the ORC. The maximum net power output was selected to compare three ORC systems, including basic ORC (B-ORC), conventional dual-pressure ORC (CD-ORC) and SFD-ORC. A genetic algorithm (GA) was used to optimize the parameters to search the maximum net power output of ORCs. The maximum net output power was taken as the standard of performance evaluation. The results show that, under the same hot water inlet temperature condition, the optimal hot water outlet temperature of B-ORC is much higher than that of CD-ORC and SFD-ORC, which indicates that less thermal energy could be utilized to convert to power in B-ORC. The optimal hot water temperature at the outlet of evaporator 1 in SFD-ORC is higher than that in CD-ORC, which means SFD-ORC could make more efficient use of the high-grade thermal energy of hot water. The SFD-ORC could obtain the highest net output power under the optimal parameter conditions, followed by the CD-ORC system, while the B-ORC has the lowest net output power. Moreover, with the increase in the hot water inlet temperature, the advantage of SFD-ORC becomes increasingly obvious. When the hot water inlet temperature is 90 °C, the net output power of SFD-ORC at is 6.22% higher than that of CD-ORC. The net output power of SFD-ORC at 130 °C increases to 9.7% higher than that of CD-ORC. The SFD-ORC presents better system performance and has great engineering application potential.

scholarly journals Energy and Exergy Analysis of Combined Organic Rankine Cycle-Single and Dual Evaporator Vapor Compression Refrigeration Cycle

2019 ◽  
Vol 9 (23) ◽  
pp. 5028 ◽  
Author(s):  
Pektezel ◽  
Acar
Keyword(s):  
Exergy Analysis ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Exergy Destruction ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Vapor Compression Refrigeration

This paper presents energy and exergy analysis of two vapor compression refrigeration cycles powered by organic Rankine cycle. Refrigeration cycle of combined system was designed with single and dual evaporators. R134a, R1234ze(E), R227ea, and R600a fluids were used as working fluids in combined systems. Influences of different parameters such as evaporator, condenser, boiler temperatures, and turbine and compressor isentropic efficiencies on COPsys and ƞex,sys were analyzed. Second law efficiency, degree of thermodynamic perfection, exergy destruction rate, and exergy destruction ratio were detected for each component in systems. R600a was determined as the most efficient working fluid for proposed systems. Both COPsys and ƞex,sys of combined ORC-single evaporator VCR cycle was detected to be higher than the system with dual evaporator.

scholarly journals Organic Rankine Cycle system performance targeting and design for multiple heat sources with simultaneous working fluid selection

2017 ◽  
Vol 142 ◽  
pp. 1950-1970 ◽  
Author(s):  
Mirko Z. Stijepovic ◽  
Athanasios I. Papadopoulos ◽  
Patrick Linke ◽  
Vladimir Stijepovic ◽  
Aleksandar S. Grujic ◽  
...  
Keyword(s):  
System Performance ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Heat Sources ◽  
Cycle System ◽  
Working Fluid Selection

Effects of Various Types of Binary Cycles on Thermal and Exergy Efficiency of Combined Flash-Binary Power Plants

2012 ◽  
Author(s):  
Mahshid Vatani ◽  
Masoud Ziabasharhagh ◽  
Shayan Amiri
Keyword(s):  
Power Plants ◽  
Organic Rankine Cycle ◽  
Internal Heat ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Maximum Efficiency ◽  
Working Fluid ◽  
Internal Heat Exchanger ◽  
Different Types ◽  
Geothermal Power

With the progress of technologies, engineers try to evaluate new and applicable ways to get high possible amount of energy from renewable resources, especially in geothermal power plants. One of the newest techniques is combining different types of geothermal cycles to decrease wastage of the energy. In the present article, thermodynamic optimization of different flash-binary geothermal power plants is studied to get maximum efficiency. The cycles studied in this paper are single and double flash-binary geothermal power plants of basic Organic Rankine Cycle (ORC), regenerative ORC and ORC with an Internal Heat Exchanger (IHE). The main gain due to using various types of ORC cycles is to determine the best and efficient type of the Rankine cycle for combined flash-binary geothermal power plants. Furthermore, in binary cycles choosing the best and practical working fluid is an important factor. Hence three different types of working fluids have been used to find the best one that gives maximum thermal and exergy efficiency of combined flash-binary geothermal power plants. According to results, the maximum thermal and exergy efficiencies both achieved in ORC with an IHE and the effective working fluid is R123.

Exergy Analysis of Solar Photovoltaic/Thermal Organic Rankine Cycle

2013 ◽  
Vol 448-453 ◽  
pp. 1509-1513 ◽  
Author(s):  
Guo Chang Zhao ◽  
Li Ping Song ◽  
Yong Wang ◽  
Xiao Chen Hou
Keyword(s):  
Exergy Analysis ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Solar Thermal ◽  
Working Fluid ◽  
Solar Photovoltaic ◽  
Generation System ◽  
Cycle System ◽  
Power Generation System

A solar thermal organic Rankine cycle (ORC) power generation system model established using R245fa as the working fluid and coupled with a solar photovoltaic generator is introduced. Thermal efficiency and exergy efficiency of the model both with and without a heat regenerator are calculated and compared. Results show the solar organic Rankine cycle system with a heat regenerator has higher thermal and exergy efficiency than the system without a heat regenerator, providing better performance in practice. This result provides a basis for further application and improvement of solar photovoltaic and the solar thermal organic Rankine cycle.

The first and second law analysis on an organic Rankine cycle with ejector

Solar Energy ◽  
2013 ◽  
Vol 93 ◽  
pp. 100-108 ◽  
Author(s):  
Xinguo Li ◽  
Xiajie Li ◽  
Qilin Zhang
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Second Law ◽  
Second Law Analysis
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