Optimization of a Novel Combined Power/Refrigeration Thermodynamic Cycle

2003 ◽  
Vol 125 (2) ◽  
pp. 212-217 ◽  
Author(s):  
Shaoguang Lu ◽  
D. Yogi Goswami
Keyword(s):  
Waste Heat ◽  
Thermodynamic Cycle ◽  
Gradient Algorithm ◽  
Cycle Performance ◽  
Working Fluid ◽  
Heat Sources ◽  
Objective Functions ◽  
Ambient Temperatures ◽  
Reduced Gradient ◽  
Generalized Reduced Gradient

A novel combined power/refrigeration thermodynamic cycle is optimized for thermal performance in this paper. The cycle uses ammonia-water binary mixture as a working fluid and can be driven by various heat sources, such as solar, geothermal, and low temperature waste heat. The optimization program, which is based on the Generalized Reduced Gradient algorithm, can be used to optimize for different objective functions. In addition, cycle performance over a range of ambient temperatures was investigated.

Optimization of a Novel Combined Power/Refrigeration Thermodynamic Cycle

Solar Energy ◽  
2002 ◽  
Author(s):  
Shaoguang Lu ◽  
D. Yogi Goswami
Keyword(s):  
Waste Heat ◽  
Thermodynamic Cycle ◽  
Cycle Performance ◽  
Working Fluid ◽  
Second Law ◽  
Optimum Conditions ◽  
Ambient Temperatures ◽  
Reduced Gradient ◽  
Generalized Reduced Gradient ◽  
Performance Conditions

A novel combined power/refrigeration thermodynamic cycle is optimized for thermal performance in this paper. The cycle uses ammonia-water binary mixture as a working fluid and can be driven by various heat sources, such as solar, geothermal and low temperature waste heat. It could produce power as well as refrigeration with power output as a primary goal. The optimization program, which is based on the Generalized Reduced Gradient (GRG) algorithm, can be used to optimize for different objective functions. Examples that maximize second law efficiency, work output and refrigeration output are presented, showing the cycle may be optimized for any desired performance parameter. In addition, cycle performance over a range of ambient temperatures was investigated. It was found that for a source temperature of 360K, which is in the range of flat plate solar collectors, both power and refrigeration outputs are achieved under optimum conditions. All performance parameters, including first and second law efficiencies, power and refrigeration output decrease as the ambient temperature goes up. On the other hand, for a source of 440K, optimum conditions do not provide any refrigeration. However, refrigeration can be obtained even for this temperature under non-optimum performance conditions.

A Novel Combined Power and Cooling Thermodynamic Cycle for Low Temperature Heat Sources: Part I — Theoretical Investigation

Solar Energy ◽  
2002 ◽  
Author(s):  
Gunmar Tamm ◽  
D. Yogi Goswami ◽  
Shaoguang Lu ◽  
Afif A. Hasan
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Waste Heat ◽  
Thermal Power ◽  
Thermodynamic Cycle ◽  
Working Fluid ◽  
Second Law ◽  
Water Mixture ◽  
Reduced Gradient Method ◽  
Generalized Reduced Gradient

A combined thermal power and cooling cycle proposed by Goswami is under intensive investigation, both theoretically and experimentally. The proposed cycle combines the Rankine and absorption refrigeration cycles, producing refrigeration while power is the primary goal. A binary ammonia-water mixture is used as the working fluid. This cycle can be used as a bottoming cycle using waste heat from a conventional power cycle or an independent cycle using low temperature sources such as geothermal and solar energy. Initial parametric studies of the cycle showed the potential for the cycle to be optimized for first or second law efficiency, as well as work or cooling output. For a solar heat source, optimization of the second law efficiency is most appropriate, since the spent heat source fluid is recycled through the solar collectors. The optimization results verified that the cycle could be optimized using the Generalized Reduced Gradient method. Theoretical results were extended to include realistic irreversibilities in the cycle, in preparation for the experimental study.

Novel Combined Power and Cooling Thermodynamic Cycle for Low Temperature Heat Sources, Part II: Experimental Investigation

2003 ◽  
Vol 125 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Gunnar Tamm ◽  
D. Yogi Goswami
Keyword(s):  
Low Temperature ◽  
System Analysis ◽  
Waste Heat ◽  
Thermal Power ◽  
Experimental System ◽  
Thermodynamic Cycle ◽  
Operating Conditions ◽  
Working Fluid ◽  
Water Mixture ◽  
Theoretical Simulation

A combined thermal power and cooling cycle proposed by Goswami is under intensive investigation, both theoretically and experimentally. The proposed cycle combines the Rankine and absorption refrigeration cycles, producing refrigeration while power is the primary goal. A binary ammonia-water mixture is used as the working fluid. This 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. An experimental system was constructed to demonstrate the feasibility of the cycle and to compare the experimental results with the theoretical simulation. Results showed that the vapor generation and absorption condensation processes work experimentally, exhibiting expected trends, but with deviations from ideal and equilibrium modeling. The potential for combined turbine work and refrigeration output was evidenced in operating the system. Analysis of losses showed where improvements could be made, in preparation for further testing over a broader range of operating conditions.

scholarly journals Development of a Pattern Recognition Methodology with Thermography and Implementation in an Experimental Study of a Boiler for a WHRS-ORC

2019 ◽  
Author(s):  
Concepción Paz ◽  
Eduardo Suarez ◽  
Miguel Concheiro ◽  
Antonio Diaz
Keyword(s):  
Pattern Recognition ◽  
Wall Temperature ◽  
Waste Heat ◽  
Combustion Engine ◽  
Organic Rankine Cycle ◽  
Exhaust System ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Cycle Performance ◽  
Working Fluid

Waste heat dissipated in the exhaust system in a combustion engine represents a major source of energy to be recovered and converted into useful work. A waste heat recovery system (WHRS) based on an Organic Rankine Cycle (ORC) is a promising approach, and has gained interest in the last few years in an automotive industry interested in reducing fuel consumption and exhaust emissions. Understanding the thermodynamic response of the boiler employed in an ORC plays an important role in steam cycle performance prediction and control system design. The aim of this study is therefore to present a methodology to study these devices by means of pattern recognition with infrared thermography. In addition, the experimental test bench and its operating conditions are described. The methodology proposed identifies the wall coordinates, traces paths, and tracks wall temperature along them in a way that can be exported for subsequent post-processing and analysis. As for the results, through the wall temperature paths on both sides (exhaust gas and working fluid) it was possible to quantitatively estimate the temperature evolution along the boiler and, in particular, the beginning and end of evaporation.

Optimal Design of Semisubmersible’s Form Based on Systems Analysis

1984 ◽  
Vol 106 (4) ◽  
pp. 524-530 ◽  
Author(s):  
S. Akagi ◽  
R. Yokoyama ◽  
K. Ito
Keyword(s):  
Optimal Design ◽  
Computer Aided Design ◽  
Optimization Problem ◽  
Design Method ◽  
Gradient Algorithm ◽  
Interpretive Structural Modeling ◽  
Reduced Gradient ◽  
Optimal Design Method ◽  
Generalized Reduced Gradient ◽  
Aided Design

With the objective of developing a computer-aided design method to seek the optimal semisubmersible’s form, hierarchical relationships among many design objectives and conditions are investigated first based on the interpretive structural modeling method. Then, an optimal design method is formulated as a nonlinear multiobjective optimization problem by adopting three mutually conflicting design objectives. A set of Pareto optimal solutions is derived numerically by adopting the generalized reduced gradient algorithm, and it is ascertained that the designer can determine the optimal form more rationally by investigating the trade-off relationships among design objectives.

Multi-Objective Optimization of a Combined Power and Cooling Cycle for Low-Grade and Midgrade Heat Sources

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Gokmen Demirkaya ◽  
Saeb Besarati ◽  
Ricardo Vasquez Padilla ◽  
Antonio Ramos Archibold ◽  
D. Yogi Goswami ◽  
...  
Keyword(s):  
Thermodynamic Cycle ◽  
Solution Concentration ◽  
Working Fluid ◽  
Low Grade ◽  
Basic Solution ◽  
Heat Sources ◽  
Fluid Mixture ◽  
Cooling Cycle ◽  
Multi Objective ◽  
First Case

Optimization of thermodynamic cycles is important for the efficient utilization of energy sources; indeed, it is more crucial for the cycles utilizing low-grade heat sources where the cycle efficiencies are smaller compared to high temperature power cycles. This paper presents the optimization of a combined power/cooling cycle, also known as the Goswami cycle, which combines the Rankine and absorption refrigeration cycles. The cycle uses a special binary fluid mixture as the working fluid and produces a power and refrigeration. In this regard, multi-objective genetic algorithms (GAs) are used for Pareto approach optimization of the thermodynamic cycle. The optimization study includes two cases. In the first case, the performance of the cycle is evaluated as it is used as a bottoming cycle and in the second case, as it is used as a top cycle utilizing solar energy or geothermal sources. The important thermodynamic objectives that have been considered in this work are, namely, work output, cooling capacity, effective first law, and exergy efficiencies. Optimization is carried out by varying the selected design variables, such as boiler temperature and pressure, rectifier temperature, and basic solution concentration. The boiler temperature is varied between 70–150 °C and 150–250 °C for the first and the second cases, respectively.

A model for fi nding the optimal routes for a combined route container train

Innotrans ◽  
2021 ◽  
pp. 15-21
Author(s):  
Chang Hao ◽  
◽  
Daria Ivanovna Kochneva ◽  
Keyword(s):  
Software Implementation ◽  
Gradient Algorithm ◽  
Rolling Stock ◽  
Optimal Route ◽  
Delivery Time ◽  
Container Transportation ◽  
Cargo Handling ◽  
Reduced Gradient ◽  
Generalized Reduced Gradient ◽  
Train Loading

The article is devoted to the development of the model for finding an optimal route for a combined route container train (CRCT), i.e. a train with a designated route and schedule, en route from the initial to the final station without reforming of a rolling stock, but carrying out cargo handling operations for loading/unloading containers at intermediate stops of the route. It is proposed to call the optimal route of a CRCT, which provides the minimum delivery time while ensuring the targeted train loading on each section and with a set value of demand for container transportation at each point of the route. A software implementation of the model in the MS Excel environment is proposed using the built-in generalized reduced gradient algorithm.

Combined Cycle for Power Generation and Refrigeration Using Low Temperature Heat Sources

2014 ◽  
Vol 3 (3) ◽  
pp. 34-56 ◽  
Author(s):  
Vijay Chauhan ◽  
P. Anil Kishan ◽  
Sateesh Gedupudi
Keyword(s):  
Power Generation ◽  
Low Temperature ◽  
Combined Cycle ◽  
Working Fluid ◽  
Heat Sources ◽  
Ambient Temperatures ◽  
Temperature Heat ◽  
Good Potential ◽  
Output Ratio ◽  
Operation Results

A combined refrigeration and power cycle, which uses ammonia-water as the working fluid, is proposed by combining Rankine and vapour absorption cycles with an advantage of varying refrigeration capacity to power output ratio. The study investigates the usage of low temperature heat sources for the cycle operation. Results of parametric analysis are presented, which show the scope for optimization. Results of thermodynamic optimization of the cycle for second law efficiency performed using genetic algorithm for different ambient temperatures are also presented. The cycle shows good potential for obtaining refrigeration and power generation.

scholarly journals Parametric Optimization and Thermodynamic Performance Comparison of Organic Trans-Critical Cycle, Steam Flash Cycle, and Steam Dual-Pressure Cycle for Waste Heat Recovery

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4623 ◽  
Author(s):  
Liya Ren ◽  
Huaixin Wang
Keyword(s):  
Heat Source ◽  
Power Output ◽  
Initial Temperature ◽  
Waste Heat ◽  
Cycle Performance ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Thermodynamic Performance ◽  
Pressure Cycle ◽  
Net Power Output

Compared with the basic organic and steam Rankine cycles, the organic trans-critical cycle (OTC), steam flash cycle (SFC) and steam dual-pressure cycle (SDC) can be regarded as the improved cycle configurations for the waste heat power recovery since they can achieve better temperature matching between the heat source and working fluid in the heat addition process. This study investigates and compares the thermodynamic performance of the OTC, SFC, and SDC based on the waste heat source from the cement kiln with an initial temperature of 320 °C and mass flow rate of 86.2 kg/s. The effects of the main parameters on the cycle performance are analyzed and the parameter optimization is performed with net power output as the objective function. Results indicate that the maximum net power output of SDC is slightly higher than that of SFC and the OTC using n-pentane provides a 19.74% increase in net power output over the SDC since it can achieve the higher use of waste heat and higher turbine efficiency. However, the turbine inlet temperature of the OTC is limited by the thermal stability of the organic working fluid, hence the SDC outputs more power than that of the OTC when the initial temperature of the exhaust gas exceeds 415 °C.

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