scholarly journals Exergy Analysis of Organic Rankine Cycle with Internal Heat Exchanger

Author(s):  
Kyoung Hoon Kim ◽  
Hyung Jong Ko ◽  
Se Woong Kim
2013 ◽  
Vol 856 ◽  
pp. 349-356 ◽  
Author(s):  
Kai Yang ◽  
Hong Guang Zhang ◽  
Zhen Wang ◽  
Jian Zhang ◽  
Fu Bin Yang ◽  
...  

Through experiment, the variation of the exhaust energy of the vehicle diesel engine is studied, a set of vehicle diesel engine-organic Rankine cycle (ORC) combined system with internal heat exchanger (IHE) is designed, the zeotropic mixtures R416A is used as the working fluids for the ORC system with IHE, by theoretical analysis and numerical calculation, the variation of the vehicle diesel engine-ORC combined system with IHE under entire operating conditions of the diesel engine is studied, the calculation results show that, when engine is operating at high speed and high torque, the performance of the vehicle diesel engine-ORC combined system with IHE is higher.


2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Nurettin Yamankaradeniz ◽  
Ali Husnu Bademlioglu ◽  
Omer Kaynakli

This study makes energy and exergy analysis of a sample organic Rankine cycle (ORC) with a heat exchanger which produces energy via a geothermal source with a temperature of 140 °C. R600a is preferred as refrigerant to be used in the cycle. The changes in exergy destructions (of irreversibility) and exergy efficiencies in each cycle element are calculated in the analyses made based on the effectiveness of heat exchanger used in cycle and evaporator temperature changing between 60 and 120 °C for fixed pinch point temperature differences in evaporator and condenser. Parameters showing system performance are assessed via second law approach. Effectiveness of heat exchanger and temperature of evaporator are taken into consideration within the scope of this study, and energy and exergy efficiencies of cycle are enhanced maximum 6.87% and 6.21% respectively. Similarly, exergy efficiencies of evaporator, heat exchanger, and condenser are increased 4%, 82%, and 1.57%, respectively, depending on the effectiveness of heat exchanger and temperature of evaporator.


2013 ◽  
Vol 442 ◽  
pp. 183-186
Author(s):  
Kyoung Hoon Kim

Exergy analysis is performed for transcritical Organic Rankine Cycle (ORC) with internal heat exchanger based on the second law of thermodynamics. Effects of source temperature as well as turbine inlet pressure (TIP) are investigated on the exergy destructions (or anergies) of the system as well as exergy efficiency. Results show that irreversibility of the system decreases with increasing TIP or decreasing source temperature. Exergy efficiency decreases with increasing source temperature; however has a maximum value with respect to TIP.


Author(s):  
Mahshid Vatani ◽  
Masoud Ziabasharhagh ◽  
Shayan Amiri

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.


Author(s):  
H. Xi ◽  
M. J. Li ◽  
Y. L. He ◽  
W. W. Yang ◽  
Y. S. Li

In the design and optimization of the ORC system, the selection of working fluid is one of the most important factors that should be considered. In this work, considering different heat sources with their temperatures ranging from 80 to 120 °C, 8 different zeotropic mixtures were proposed and their thermodynamic and economic performance for two types of traditional ORC systems (i.e. basic organic Rankine cycle, BORC and organic Rankine cycle with internal heat exchanger, IHORC) were investigated. Firstly, economic analysis were performed for both systems; Secondly, genetic algorithm (GA) was then introduced to determine the optimal fractions and other operation parameters for zeotropic mixtures under different working conditions and systems, the algorithm implementation process was described. Thirdly, the optimization studies were performed by using annual cash flow as the objective function. The optimal thermodynamic performance of different zeotropic mixtures and their components were both calculated and compared. For the different heat sources temperatures, the optimal zeotropic mixtures and their optimal fraction were recommended according to the calculated results.


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