Thermodynamic modelling of three-stage combined cycle power systems utilising ammonia-water mixture as a working fluid in bottoming cycle

2014 ◽  
Vol 14 (3) ◽  
pp. 320 ◽  
Author(s):  
Amin Momeni ◽  
Hossein Shokouhmand
Keyword(s):  
Power Systems ◽  
Combined Cycle ◽  
Thermodynamic Modelling ◽  
Working Fluid ◽  
Water Mixture ◽  
Ammonia Water

scholarly journals Thermodynamic analysis and simulation of a new combined power and refrigeration cycle using artificial neural network

2011 ◽  
Vol 15 (1) ◽  
pp. 29-41 ◽  
Author(s):  
Abdolreza Fazeli ◽  
Hossein Rezvantalab ◽  
Farshad Kowsary
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Heat Source ◽  
Exergy Efficiency ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Working Fluid ◽  
Refrigeration Cycle ◽  
Water Mixture ◽  
Artificial Neural

In this study, a new combined power and refrigeration cycle is proposed, which combines the Rankine and absorption refrigeration cycles. Using a binary ammonia-water mixture as the working fluid, this combined cycle produces both power and refrigeration output simultaneously by employing only one external heat source. In order to achieve the highest possible exergy efficiency, a secondary turbine is inserted to expand the hot weak solution leaving the boiler. Moreover, an artificial neural network (ANN) is used to simulate the thermodynamic properties and the relationship between the input thermodynamic variables on the cycle performance. It is shown that turbine inlet pressure, as well as heat source and refrigeration temperatures have significant effects on the net power output, refrigeration output and exergy efficiency of the combined cycle. In addition, the results of ANN are in excellent agreement with the mathematical simulation and cover a wider range for evaluation of cycle performance.

OS2-22 Effect of Mass Fraction of Ammonia on OTEC Systemwith Ammonia/water Mixture as Working Fluid

2007 ◽  
Vol 2007.12 (0) ◽  
pp. 367-368
Author(s):  
Yasuyuki IKEGAMI ◽  
Hiroyuki ASOU ◽  
Takeshi YASUNAGA ◽  
Hirokazu MANDA ◽  
Junichi INADOMI
Keyword(s):  
Mass Fraction ◽  
Working Fluid ◽  
Water Mixture ◽  
Ammonia Water

Considerations on the Design Principles for a Binary Mixture Heat Recovery Boiler

1992 ◽  
Vol 114 (4) ◽  
pp. 701-706 ◽  
Author(s):  
S. S. Stecco ◽  
U. Desideri
Keyword(s):  
Heat Transfer ◽  
Binary Mixture ◽  
Binary Mixtures ◽  
Heat Recovery ◽  
Combined Cycle ◽  
Working Fluid ◽  
Heat Recovery Boiler ◽  
Water Mixture ◽  
Volume Viscosity ◽  
Recovery Boiler

The use of a binary mixture as a working fluid in bottoming cycles has in recent years been recognized as a means of improving combined cycle efficiency. There is, however, quite a number of studies dealing with components of plants that employ fluids other than water, and particularly binary mixtures. Due to different specific volume, viscosity, thermal conductivity, and Prandtl number, heat recovery boilers designed to work with water require certain modifications before they can be used with binary mixtures. Since a binary mixture is able to recover more heat from the exhaust fumes than water, the temperature difference between the hot and the cold fluids is generally lower over the whole recovery boiler; this necessitates greater care in sizing the tube bundles in order to avoid an excessive heat transfer surface per unit of thermal power exchanged. The aim of this paper is to provide some general criteria for the design of a heat recovery boiler for a binary mixture, by showing the influence of various dimensional parameters on the heat surface and pressure drop both in the cold and the hot side. Heat transfer coefficients and pressure drops in the hot side were computed by means of correlations found in the literature. A particular application was studied for an ammonia-water mixture, used in the Kalina cycles, which represents one of the most interesting binary cycles proposed so far.

Flexible Heat-to-Power Ratio Co-Generation System With Ammonia-Water Mixture Cycles at Bottoming

2003 ◽  
Author(s):  
Keisuke Takeshita ◽  
Yoshiharu Amano ◽  
Takumi Hashizume ◽  
Akira Usui ◽  
Yoshiaki Tanzawa
Keyword(s):  
Working Fluid ◽  
Water Mixture ◽  
Power Ratio ◽  
System Configuration ◽  
Generation System ◽  
Ammonia Water ◽  
Cogeneration System ◽  
Ammonia Absorption ◽  
Hybrid Configuration ◽  
Absorption Refrigerator

This paper presents the experimental study of a unique cogeneration system which the authors call the “Advanced Co-Generation System (ACGS)”. It mainly consists of three turbine systems and an ammonia absorption refrigerator (AAR). The specialty of the ACGS is the bottoming stage employing an ammonia-water mixture (AWM) as the working fluid. First, the overall system configuration and some experimental results at the steady state are shown. The experimental investigation shows that the AWM bottoming cycles contribute to a higher efficiency of the system. An increase of 5–10% in electric power compared to a conventional co-generation system (CGS) is confirmed. Next, a hybrid configuration of the AWM turbine (AWMT) cycle and the AAR is investigated. A simulation model is constructed. The results of the simulation show that the hybrid configuration performs at about 14% higher efficiency.

Performance Analysis of a Rankine-Goswami Combined Cycle

2011 ◽  
Author(s):  
Ricardo Vasquez Padilla ◽  
Antonio Ramos Archibold ◽  
Gokmen Demirkaya ◽  
Saeb Besarati ◽  
D. Yogi Goswami ◽  
...  
Keyword(s):  
Power Plants ◽  
Rankine Cycle ◽  
Ammonia Concentration ◽  
Combined Cycle ◽  
Working Fluid ◽  
Base Case ◽  
Water Mixture ◽  
Solar Power Plants ◽  
Combined Cycles ◽  
The Cost

Improving the efficiency of thermodynamic cycles plays a fundamental role in reducing the cost of solar power plants. These plants work normally with Rankine cycles which present some disadvantages due to the thermodynamic behavior of steam at low pressures. These disadvantages can be reduced by introducing alternatives such as combined cycles which combine the best features of each cycle. In this paper a combined Rankine-Goswami cycle (RGC) is proposed and a thermodynamic analysis is conducted. The Goswami cycle, used as a bottoming cycle, uses ammonia-water mixture as the working fluid and produces power and refrigeration while power is the primary goal. This bottoming cycle, reduces the energy losses in the traditional condenser and eliminates the high specific volume and poor vapor quality presented in the last stages of the lower pressure turbine in the Rankine cycle. In addition, the use of absorption condensation in the Goswami cycle, for regeneration of the strong solution, allows operating the low pressure side of the cycle above atmospheric pressure which eliminates the need for maintaining a vacuum pressure in the condenser. The performance of the proposed combined Rankine-Goswami cycle, under full load, was investigated for applications in parabolic trough solar thermal plants for a range from 40 to 50 MW sizes. A sensitivity analysis to study the effect of the ammonia concentration, condenser pressure and rectifier concentration on the cycle efficiency, network and cooling was performed. The results indicate that the proposed RGC provide a difference in net power output between 15.7 and 42.3% for condenser pressures between 1 to 9 bars. The maximum effective first law and exergy efficiencies for an ammonia mass fraction of 0.5 are calculated as 36.7% and 24.7% respectively for the base case (no superheater or rectifier process).

Parametric Study of a Combined Power and Cooling Thermodynamic Cycle for Low Temperature Heat Sources

2009 ◽  
Author(s):  
Ricardo Vasquez Padilla ◽  
Gokmen Demirkaya ◽  
D. Yogi Goswami ◽  
Elias L. Stefanakos
Keyword(s):  
Low Temperature ◽  
Parametric Study ◽  
Waste Heat ◽  
Ammonia Concentration ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Working Fluid ◽  
Basic Solution ◽  
Water Mixture

A combined power/cooling cycle, which combines the Rankine and absorption refrigeration cycles, uses ammonia-water mixture as a working fluid and produces power and refrigeration while power is the primary goal. This cycle, also known as the Goswami Cycle, can be used as a bottoming cycle using waste heat from a conventional power cycle or as an independent cycle using low temperature sources such as geothermal and solar energy. This paper presents a parametric analysis of the combined cycle. Parametric study of the cycle was carried out in the commercial software Chemcad 6.1. The thermodynamic property data used in simulations were validated with experimental data. Chemcad model was also compared with simulations previously carried out in the process simulator Aspen Plus. The agreement between the two sets has proved the accuracy of the model developed in Chemcad. Then, optimum operating conditions were found for a range of ammonia concentration in the basic solution, isentropic expander efficiency and boiler pressure. It is shown that the cycle can be optimized for net work, cooling output, effective first and exergy efficiencies.

Organic Working Fluids for a Combined Power and Cooling Cycle

2005 ◽  
Vol 127 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Sanjay Vijayaraghavan ◽  
D. Y. Goswami
Keyword(s):  
Power Plants ◽  
Thermodynamic Cycle ◽  
Working Fluid ◽  
Water Mixture ◽  
Heat Sources ◽  
Absorption Refrigeration ◽  
Ammonia Water ◽  
Working Fluids ◽  
Fluid Mixtures ◽  
Advantages And Disadvantages

A new thermodynamic cycle has been developed for the simultaneous production of power and cooling from low-temperature heat sources. The proposed cycle combines the Rankine and absorption refrigeration cycles, providing power and cooling as useful outputs. Initial studies were performed with an ammonia-water mixture as the working fluid in the cycle. This work extends the application of the cycle to working fluids consisting of organic fluid mixtures. Organic working fluids have been used successfully in geothermal power plants, as working fluids in Rankine cycles. An advantage of using organic working fluids is that the industry has experience with building turbines for these fluids. A commercially available optimization program has been used to maximize the thermodynamic performance of the cycle. The advantages and disadvantages of using organic fluid mixtures as opposed to an ammonia-water mixture are discussed. It is found that thermodynamic efficiencies achievable with organic fluid mixtures, under optimum conditions, are lower than those obtained with ammonia-water mixtures. Further, the refrigeration temperatures achievable using organic fluid mixtures are higher than those using ammonia-water mixtures.

scholarly journals Applying Kalina Technology to a Bottoming Cycle for Utility Combined Cycles

1987 ◽  
Author(s):  
A. L. Kalina ◽  
H. M. Leibowitz
Keyword(s):  
Combined Cycle ◽  
Cycle Performance ◽  
Working Fluid ◽  
Water Mixture ◽  
Pinch Point ◽  
Kalina Cycle ◽  
Pressure Steam ◽  
Combined Cycles ◽  
Steam Plant ◽  
Steam Cycle

A new power generation technology often referred to as the Kalina cycle, is being developed as a direct replacement for the Rankine steam cycle. It may be applied to any thermal heat source, low or high temperature. Among several Kalina cycle variations there is one that is particularly well suited as a bottoming cycle for utility combined cycle applications. It is the subject of this paper. Using an ammonia/water mixture as the working fluid and a condensing system based on absorption refrigeration principles the Kalina bottoming cycle outperforms a triple pressure steam cycle by 16 percent. Additionally, this version of the Kalina cycle is characterized by an intercooling feature between turbine stages, diametrically opposite to normal reheating practice in steam plants. Energy and mass balances are presented for a 200 MWe Kalina bottoming cycle. Kalina cycle performance is compared to a triple pressure steam plant. At a peak cycle temperature of 950° F the Kalina plant produces 223.5 MW vs. 192.6 MW for the triple pressure steam plant, an improvement of 16.0 percent. Reducing the economizer pinch point to 15° F results in a performance improvement in excess of 30 percent.

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