Transient Energy and Exergy Analyses of a Solar Based Integrated System

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
M. Rabbani ◽  
T. A. H. Ratlamwala ◽  
I. Dincer
Keyword(s):  
Pressure Ratio ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Integrated System ◽  
Work Output ◽  
Cycle System ◽  
Energy And Exergy ◽  
Transient Energy ◽  
Gas Turbine Cycle ◽  
Exergy Analyses

The present study focuses on transient energy and exergy analyses of an integrated heliostat field, gas-turbine cycle and organic Rankine cycle system capable of generating power and heat in a carbon-free manner. A parametric study is carried out to ascertain the effect of varying the exit temperature of salt and the pressure ratio (PR) on the net work output, rate of heat lost from the receiver, and energy and exergy efficiencies for 365 days of the year and from 10:00 am to 2:00 pm. The results are obtained for the city of Toronto, Canada and indicate that the net work output increases from 1481 to 3339 kW with a rise in the exit salt temperature from 1200 to 1600 K. The energy and exergy efficiencies of the integrated system vary from 0.72 to 0.78 and 0.36 to 0.46, respectively, with a rise in the exit salt temperature. The energy and exergy efficiencies vary from 0.68 to 0.73 and 0.35 to 0.39, respectively, with an increase in the PR from 10 to 20.

Empirical Models for a Screw Expander Based on Experimental Data From Organic Rankine Cycle System Testing

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Vamshi Krishna Avadhanula ◽  
Chuen-Sen Lin
Keyword(s):  
Experimental Data ◽  
Power Output ◽  
Pressure Ratio ◽  
Organic Rankine Cycle ◽  
Volume Ratio ◽  
Rankine Cycle ◽  
Empirical Models ◽  
Working Fluid ◽  
Work Output ◽  
Experimental Values

The screw expander discussed in this work was part of a 50 kW organic Rankine cycle (ORC) system. The ORC was tested under different conditions in heat source and heat sink. In conjunction with collecting data for the ORC system, experimental data were also collected for the individual components of the ORC, viz. evaporator, preheater, screw expander, working fluid pump, and condenser. Experimental data for the screw expander were used to develop the two empirical models discussed in this paper for estimating screw expander performance. As the physical parameters of the screw expander discussed in this article are not known, a “black-box” approach was followed to estimate screw expander power output, based on expander inlet and outlet pressure and temperature data. Refrigerant R245fa was used as the working fluid in the ORC. The experimental data showed that the screw expander had ranges of pressure ratio (2.70 to 6.54), volume ratio (2.54 to 6.20), and power output (10 to 51.5 kW). Of the two empirical models, the first model is based on the polytropic expansion process, in which an expression for the polytropic exponent is found by applying regression curve-fitting analysis as a function of the expander pressure ratio and volume ratio. In the second model, an expression for screw expander work output is found by applying regression curve-fitting analysis as a function of the expander isentropic work output. The predicted screw expander power output using the polytropic exponent model was within ±10% of experimental values; the predicted screw expander power output using the isentropic work output model was within ±7.5% of experimental values.

Energy and exergy analyses of a biomass trigeneration system using an organic Rankine cycle

Energy ◽  
2012 ◽  
Vol 45 (1) ◽  
pp. 975-985 ◽  
Author(s):  
Fahad A. Al-Sulaiman ◽  
Ibrahim Dincer ◽  
Feridun Hamdullahpur
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Energy And Exergy ◽  
Exergy Analyses

scholarly journals Energy and Exergy Analyses of a Solid Oxide Fuel Cell-Gas Turbine-Organic Rankine Cycle Power Plant with Liquefied Natural Gas as Heat Sink

Entropy ◽  
2018 ◽  
Vol 20 (7) ◽  
pp. 484 ◽  
Author(s):  
Mohammad Ahmadi ◽  
Mirhadi Sadaghiani ◽  
Fathollah Pourfayaz ◽  
Mahyar Ghazvini ◽  
Omid Mahian ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Power Plant ◽  
Gas Turbine ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Liquefied Natural Gas ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Energy And Exergy ◽  
Exergy Analyses

scholarly journals Energy and exergy analysis of a combined refrigeration and waste heat driven organic Rankine cycle system

2017 ◽  
Vol 21 (6 Part A) ◽  
pp. 2621-2631 ◽  
Author(s):  
Ertugrul Cihan ◽  
Barıs Kavasogullari
Keyword(s):  
Exergy Analysis ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Power Cycle ◽  
Cycle System ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Organic Fluids

Energy and exergy analysis of a combined refrigeration and waste heat driven organic Rankine cycle system were studied theoretically in this paper. In order to complete refrigeration process, the obtained kinetic energy was supplied to the compressor of the refrigeration cycle. Turbine, in power cycle, was driven by organic working fluid that exits boiler with high temperature and pressure. Theoretical performances of proposed system were evaluated employing five different organic fluids which are R123, R600, R245fa, R141b, and R600a. Moreover, the change of thermal and exergy efficiencies were examined by changing the boiling, condensing, and evaporating temperatures. As a result of energy and exergy analysis of the proposed system, most appropriate organic working fluid was determined as R141b.

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.

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