Papers by Oguz Salim Sogut
Renewable Energy, Jul 1, 2005
An optimal performance analysis for an equivalent Carnot-like cycle heat engine of a parabolictro... more An optimal performance analysis for an equivalent Carnot-like cycle heat engine of a parabolictrough direct-steam-generation solar driven Rankine cycle power plant at maximum power and maximum power density conditions is performed. Simultaneous radiation-convection and only radiation heat transfer mechanisms from solar concentrating collector, which is the high temperature thermal reservoir, are considered separately. Heat rejection to the low temperature thermal reservoir is assumed to be convection dominated. Irreversibilities are taken into account through the finite-rate heat transfer between the fixed temperature thermal reservoirs and the internally reversible heat engine. Comparisons proved that the performance of a solar driven Carnot-like heat engine at maximum power density conditions, which receives thermal energy by either radiation-convection or only radiation heat transfer mechanism and rejects its unavailable portion to surroundings by convective heat transfer through heat exchangers, has the characteristics of (1) a solar driven Carnot heat engine at maximum power conditions, having radiation heat transfer at high and convective heat transfer at low temperature heat exchangers respectively, as the allocation parameter takes small values, and of (2) a Carnot heat engine at maximum power density conditions, having convective heat transfer at both heat exchangers, as the allocation parameter takes large values. Comprehensive discussions on the effect of heat transfer mechanisms are provided.
Applied Energy, Sep 1, 2005
An ecological performance analysis for an irreversible dual cycle has been performed by employing... more An ecological performance analysis for an irreversible dual cycle has been performed by employing the new thermo-ecological criterion as the objective function. The objective function is the ecological coefficient of performance (ECOP) and defined as the power output per unit loss rate of availability. A comprehensive numerical study is carried out to investigate the general and optimal performances of the irreversible dual-cycle having a finite-rate of heat transfer, heat leak and internal irreversibilities based on the ECOP objective function. Comparisons with an alternative ecological function defined in the literature and also with the maximum power output condition are provided to establish the utility of the new ecological performance coefficient. The results indicate that the dual cycle considered working at maximum ECOP conditions has a significant advantage in terms of entropy-generation rate and thermal efficiency.
International Journal of Energy Research, 2006
In this study, the influence of the cooling water temperature on the thermal efficiency of a conc... more In this study, the influence of the cooling water temperature on the thermal efficiency of a conceptual pressurized-water reactor nuclear-power plant is studied through an energy analysis based on the first law of thermodynamics to gain some new insights into the plant performance. The change in the cooling water temperature can be experienced due to the seasonal changes in climatic conditions at plant site. It can also come into the question of design processes for the plant site selection. In the analysis, it is considered that the condenser vacuum varies with the temperature of cooling water extracted from environment into the condenser. The main findings of the paper is that the impact of 18C increase in temperature of the coolant extracted from environment is predicted to yield a decrease of $0.45 and $0.12% in the power output and the thermal efficiency of the pressurized-water reactor nuclear-power plant considered, respectively.
Developing criteria for advanced exergoeconomic performance analysis of thermal energy systems: Application to a marine steam power plant
Energy, Mar 1, 2023
International Journal of Vehicle Design, 1999
Pseudomonas aeruginosa, Escherichia coli, Aspergilllus niger and Penicillium chrysogenum isolated... more Pseudomonas aeruginosa, Escherichia coli, Aspergilllus niger and Penicillium chrysogenum isolated from tannery effluent-contaminated soil showed resistance to chromium [Cr (VI)] with minimum inhibitory concentrations (MIC) of 80-120 mg/l in potato dextrose or nutrient agar. This increased to 100-150 mg/l in glucose and yeast extract supplemented mineral salts medium. Significant removal of Cr (VI) occurred in tannery effluents treated with the isolates singly, although reductions were >0.05 mg/l (stipulated limit) in all treatments. Chromium was reduced in glucose, beef and yeast extracts supplemented effluents to non-detectable levels < 0.05 mg/l in all except in E. coli treatment. However, mixed cultures' treatment of non-supplemented effluent reduced Cr (V1) below 0.05 mg/l with the consortium of P. aeruginosa, P. chysogenum and A. niger reaching 99.6-100% removal. Mixed bacterial and fungal culture may be of potential cost effective application in the removal of chromium in tannery wastes.
The effect of heat loss on the performance of a solar-driven heat engine
Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, Mar 30, 2009
An optimal performance analysis of a parabolic-trough direct-steam-generation solar-driven Rankin... more An optimal performance analysis of a parabolic-trough direct-steam-generation solar-driven Rankine cycle power plant at maximum power (MP) and under maximum power density (MPD) conditions is performed numerically to investigate the effects of heat loss from the heat source and working fluid. In this study, the ideal Rankine cycle of the solar-driven power plant is modified into an equivalent Carnot-like cycle with a finite-rate heat transfer. The main assumptions of this study include that: (a) the parabolic collector is the thermal reservoir at a high temperature, (b) the heat transfer process between the collector and the working fluid is through either radiation and convection simultaneously or radiation only, and (c) the heat transfer process from the working fluid to the low-temperature thermal reservoir is convection dominated. Comprehensive discussions on the effect of heat loss during the heat transfer process from the hot thermal reservoir to the working fluid in the parabolic-trough solar collector are provided. The major results of this study can be summarized as follows: (a) the working fluid temperature at the hot-side heat exchanger decreases remarkably whereas the working fluid temperature at the cold-side heat exchanger does not show any significant change with increasing heat loss, (b) the MP, MPD, and thermal efficiencies decrease with increasing heat loss, and (c) the effect of heat loss on the decrease of thermal efficiency increases when convection is the dominant heat transfer mode at the hot-side heat exchanger.
International journal of applied thermodynamics, Sep 1, 2017
In this paper, superheated and saturated vapor ORCs commonly utilized as waste heat recovery syst... more In this paper, superheated and saturated vapor ORCs commonly utilized as waste heat recovery systems of a marine power plant are investigated. First, a parametric study with different organic fluids has been carried out by applying conventional exergy and exergoeconomic analyses to the system considered in order to identify the best possible operating conditions and also to evaluate the findings of conventional exergy-based analyses. Then, advanced exergy and exergoeconomic analyses have been performed on ORCs by splitting exergy destruction rates, exergy destruction costs and investment costs of components and overall system to identify avoidable parts of costs and exergy destructions. Finally, decision criteria were suggested on the selection of more appropriate system depending on the results of the analysis.
Energy, Nov 1, 2018
Stricter rules and regulations about emissions for marine vessels and escalating fuel prices have... more Stricter rules and regulations about emissions for marine vessels and escalating fuel prices have motivated researchers and engineers to study further on improving fuel efficiency. Thus, it has become crucial to estimate the improvement potential and the sources of irreversibilities within energy systems. In this paper conventional and advanced exergy analyses are applied to a marine steam power plant to reveal insights which may help designers to make decisions on component renewal issues. The results of the study showed that the highest exergy destruction is within the boiler due to chemical reactions. Moreover, it has the highest avoidable exergy destruction. Pumps in the system contribute to the destruction in small percentages. Turbines have more importance compared to the heat exchangers. The findings for avoidable endogenous exergy destructions indicated that the improvement efforts should be focused essentially on boiler, turbines, condenser and pump equipment respectively, and that feed water heaters could be improved externally by improving other components. It is also concluded that the overall system has a 10% improvement potential of the exergy efficiency, of which almost three out of four is due to two components namely, boiler (6%), and low pressure turbine (1.3%), other components have smaller room for improvement. Keywords: Steam power plant, marine energy systems, advanced exergy analysis, Energy Efficiency Design Index Highlights: A marine steam power plant is simplified for advanced exergy analysis and its accuracy is validated with the real data from literature. Overall system has a 10% exergy efficiency improvement potential. Improvements in boiler, and 3 rd stage of low pressure turbine could recover 73% of overall efficiency improvement potential.
Developing criteria for advanced exergoeconomic performance analysis of thermal energy systems: Application to a marine steam power plant
Energy
The paper reports on the results of a theoretical investigation on the computer-aided simulation ... more The paper reports on the results of a theoretical investigation on the computer-aided simulation of a diesel engine under variable load conditions. The variable load conditions were simulated by altering the amount of fuel injection to engine cylinders. The computer simulation program employs the well established Method of Characteristics to simulate the unsteady gas flow in the intake and exhaust manifolds of the engine. A heat release scheme is employed for the in-cylinder calculations and a turbocharger simulation routine is also incorporated into the code. For the validation of the results, the MTU 16V 396 TB34 D stationary diesel generator engine data were used. The variable load conditions of 1/4th of the full load up to full load in 1/4th increments and 10% overload conditions were considered. The measured and calculated values for the effective power, mean effective pressure, specific fuel consumption and thermal efficiency were compared and found to be in good agreement.
This paper deals with a theoretical investigation of the influence of different heat release rate... more This paper deals with a theoretical investigation of the influence of different heat release rates on the performance curves of a diesel engine. The study was further extended to determine the theoretical optimum heat release rate diagram without exceeding the construction constraints of the engine. A marine diesel engine of 16 cylinders, 4 valve per cylinder, direct injection supercharged type was considered. A well proven computer programme for the complete simulation of diesel engines was employed in the study. The computer code is capable of simulating the unsteady gas flow in the manifolds, in cylinder processes and the turbocharger. The maximum combustion pressure, specific fuel consumption and effective power of the engine cylinders were compared for the different heat release rate cases. The time resolved pressure curves for the intake and exhaust manifolds were also included and the effects of different heat release rates on these diagrams were analyzed.
Journal of ETA Maritime Science, 2017
In this study, the effects of piston geometry and combustion process parameters on the performanc... more In this study, the effects of piston geometry and combustion process parameters on the performance of methane burned dual fuel engines were investigated. For this purpose, three-dimensional computational fluid dynamics-based simulation modelling is combined with method of Design of Experiments (DOE) and Kriging metamodeling. AvL Fire 3-D CFD software was used in the modelling of dual fuel engine. Through the DOE method of Latin Hypercube Sampling efficient sampling points were determined in 6 dimentional parameter space. By Kriging metamodel, sufficient prediction results were obtained about the effect of piston geometry and combustion process parameters on engine performance. It has been found out that the proposed surrogate model is consistent with other approaches in the literature. Furthermore, it has been speculated that the results of this study will contribute to methane fuelled compression ignition engine studies related to performance enhancement.
Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment, 2019
In this article, a mathematical replica of the propulsive installation of a large container ship ... more In this article, a mathematical replica of the propulsive installation of a large container ship is presented. The ship propulsion is accomplished by a large two-stroke marine diesel engine driving a marine propeller. The main new idea introduced by this research consists in using the Subsystem-Enabling feature available in the MATLAB Simulink® environment to control the execution of the working sequences of the main propulsion two-stroke diesel engine. The benefits brought by this model implementation approach are its simplicity and its applicability to all the blocks of the diesel engine model, these blocks can be created to represent one engine working sequence and then duplicated to represent the remaining engine sequences, and finally, the blocks related to each sequence can be grouped in subsystems and controlled by a single subsystem monitoring the engine events according to the value of the crankshaft angle; consequently, the overall Simulink model building and execution pro...
Energy, 2018
Stricter rules and regulations about emissions for marine vessels and escalating fuel prices have... more Stricter rules and regulations about emissions for marine vessels and escalating fuel prices have motivated researchers and engineers to study further on improving fuel efficiency. Thus, it has become crucial to estimate the improvement potential and the sources of irreversibilities within energy systems. In this paper conventional and advanced exergy analyses are applied to a marine steam power plant to reveal insights which may help designers to make decisions on component renewal issues. The results of the study showed that the highest exergy destruction is within the boiler due to chemical reactions. Moreover, it has the highest avoidable exergy destruction. Pumps in the system contribute to the destruction in small percentages. Turbines have more importance compared to the heat exchangers. The findings for avoidable endogenous exergy destructions indicated that the improvement efforts should be focused essentially on boiler, turbines, condenser and pump equipment respectively, and that feed water heaters could be improved externally by improving other components. It is also concluded that the overall system has a 10% improvement potential of the exergy efficiency, of which almost three out of four is due to two components namely, boiler (6%), and low pressure turbine (1.3%), other components have smaller room for improvement. Keywords: Steam power plant, marine energy systems, advanced exergy analysis, Energy Efficiency Design Index Highlights: A marine steam power plant is simplified for advanced exergy analysis and its accuracy is validated with the real data from literature. Overall system has a 10% exergy efficiency improvement potential. Improvements in boiler, and 3 rd stage of low pressure turbine could recover 73% of overall efficiency improvement potential.
International Journal of Thermodynamics, 2017
In this paper, superheated and saturated vapor ORCs commonly utilized as waste heat recovery syst... more In this paper, superheated and saturated vapor ORCs commonly utilized as waste heat recovery systems of a marine power plant are investigated. First, a parametric study with different organic fluids has been carried out by applying conventional exergy and exergoeconomic analyses to the system considered in order to identify the best possible operating conditions and also to evaluate the findings of conventional exergy-based analyses. Then, advanced exergy and exergoeconomic analyses have been performed on ORCs by splitting exergy destruction rates, exergy destruction costs and investment costs of components and overall system to identify avoidable parts of costs and exergy destructions. Finally, decision criteria were suggested on the selection of more appropriate system depending on the results of the analysis.
Effect of heat leakage on the performance of a twin-spool turbofan engine
International Journal of Exergy, 2016
The effect of heat leakage from a twin-spool turbofan engine to the ambient air on the performanc... more The effect of heat leakage from a twin-spool turbofan engine to the ambient air on the performance of the engine for a commercial aircraft is investigated. Effects of heat leakage on the variation of the performance indicators of coefficient of ecological performance, overall efficiency, exergy destruction factor, thrust specific fuel consumption and entropy generation rate with respect to the design parameters of compressor and fan pressure ratios, by-pass ratio and turbine inlet temperature are investigated numerically. The main findings are as follows: (i) Effect of heat leakage from the combustion chamber to the by-pass air on the coefficient of ecological performance, exergy destruction factor and entropy generation rate is considerably large when compared to that on the other performance indicators especially for small values of design parameters except for turbine inlet temperature. (ii) Effect of heat leakage on the performance indicators is significant for small values of turbine inlet temperature and large values of the other design parameters.
The Use of Gas Dynamics to Link In-Cylinder and Exhaust System Unburnt Hydrocarbon Measurements on a Spark Ignition Engine
SAE Technical Paper Series, 1991
Engineering technical paper: The Use of Gas Dynamics to Link In-Cylinder and Exhaust System Unbur... more Engineering technical paper: The Use of Gas Dynamics to Link In-Cylinder and Exhaust System Unburnt Hydrocarbon Measurements on a Spark Ignition Engine.
Mean value modeling and model predictive control of a turbocharged diesel engine airpath
Sustainable Maritime Transportation and Exploitation of Sea Resources, 2011
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Papers by Oguz Salim Sogut