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Global natural gas demand is expected to continue to grow strongly. Liquefied Natural Gas (LNG) m... more Global natural gas demand is expected to continue to grow strongly. Liquefied Natural Gas (LNG) mainly consists of methane after the liquefaction process which takes 600 times less volume and this issue makes Natural Gas economical to be transported by ship. As LNG offers greater trade flexibility than pipeline transport, the investigation of LNG technologies was one of the most significant issues of the years. This challenge is growing by increasing the demand of LNG and expecting its lower unit cost. The growth in the LNG market and the need to improve process efficiencies under different working conditions resulted in the implementation of new liquefaction technologies. C3MR process is one of the most popular technologies of LNG production using a simple propane refrigeration loop for natural gas pre-cooling. The liquefaction and sub-cooling processes are both within liquefaction block in this technology. In order to liquefy the huge capacity of natural gas a decision of separating Sub-Cooling block as an extra independent block came to industry. The purpose of this parer is to evaluate the C3MR process by introducing the separate Sub-Cooling block at the end of this simulated block. The thermodynamic results are obtained from the simulation made with the Aspen Plus software. The results of the energetic and exergetic analysis are presented to compare all evaluated possibilities of this new technology. The conventional exergetic analysis of the this process evaluated in this thesis has provided useful information about the inefficiencies in the components and the overall system.

Handbook of Research on Advances and Applications in Refrigeration Systems and Technologies, 2015

Encyclopedia of Physical Science and Technology, 2003

Progress in Energy and Combustion Science, 1993

This article discusses the development, state-of-the-art and applications of exergy analysis and ... more This article discusses the development, state-of-the-art and applications of exergy analysis and thermoeconomics (exergoeconomics). The latter is a relatively new method that combines exergy with conventional concepts from engineering economics to evaluate and optimize the design and performance of energy systems. This paper is written mainly for the person interested in applying tbermoeconomics to an energy system. It reviews the history of exergy analysis and thermoeconomics, the performance evaluation of an energy system from the viewpoints of the second law of thermodynamics and thermoeconomics as well as applications of thermoeconomic optimization techniques.

Chemical Engineering & Technology, 1996

Energy Conversion and Management, 2015

ABSTRACT Exergetic and exergoeconomic analyses are often used to evaluate the performance of ener... more ABSTRACT Exergetic and exergoeconomic analyses are often used to evaluate the performance of energy systems from the thermodynamic and economic points of view. While a conventional exergetic analysis can be used to recognize the sources of inefficiencies, the so-called advanced exergy-based analysis is convenient for identifying the real potential for thermodynamic improvements and the system component interactions by splitting the exergy destruction and the total operating cost within each component into endogenous/exogenous and unavoidable/avoidable parts. In this study for the first time an advanced exergoeconomic analysis is applied to a gas-engine-driven heat pump (GEHP) drying system used in food drying for evaluating its performance along with each component. The advanced exergoeconomic analysis shows that the unavoidable part of the exergy destruction cost rate within the components of the system is lower than the avoidable part. The most important components based on the total avoidable costs are drying ducts, the condenser and the expansion valve. The inefficiencies within the condenser could particularly be improved by structural improvements of the whole system and the remaining system components. Finally, it can be concluded that the internal design changes play a more essential role in determining the cost of each component.

Energies

This is a review of the concepts of purpose, direction, and objective in the discipline of thermo... more This is a review of the concepts of purpose, direction, and objective in the discipline of thermodynamics, which is a pillar of physics, natural sciences, life science, and engineering science. Reviewed is the relentless evolution of this discipline toward accounting for evolutionary design with direction, and for establishing the concept of purpose in methodologies of modeling, analysis, teaching, and design optimization. Evolution is change after change toward flow access, with direction in time, and purpose. Evolution does not have an ‘end’. In thermodynamics, purpose is already the defining feature of methods that have emerged to guide and facilitate the generation, distribution, and use of motive power, heating, and cooling: thermodynamic optimization, exergy-based methods (i.e., exergetic, exergoeconomic, and exergoenvironmental analysis), entropy generation minimization, extended exergy, environomics, thermoecology, finite time thermodynamics, pinch analysis, animal design, g...

Entropy

The transition towards higher shares of electricity generation from renewable energy sources is s... more The transition towards higher shares of electricity generation from renewable energy sources is shown to be significantly slower in developing countries with low-cost fossil fuel resources. Integrating conventional power plants with concentrated solar power may facilitate the transition towards a more sustainable power production. In this paper, a novel natural gas-fired integrated solar combined-cycle power plant was proposed, evaluated, and optimized with exergy-based methods. The proposed system utilizes the advantages of combined-cycle power plants, direct steam generation, and linear Fresnel collectors to provide 475 MW baseload power in Aswan, Egypt. The proposed system is found to reach exergetic efficiencies of 50.7% and 58.1% for day and night operations, respectively. In economic analysis, a weighted average levelized cost of electricity of 40.0 $/MWh based on the number of day and night operation hours is identified. In exergoeconomic analysis, the costs of thermodynamic ...

E3S Web of Conferences

Allam cycle is a novel cycle that capitalizes on the unique thermodynamic properties of supercrit... more Allam cycle is a novel cycle that capitalizes on the unique thermodynamic properties of supercritical CO2 and the advantages of oxy-combustion for power generation. It is a high-pressure supercritical carbon dioxide cycle designed to combust fossil fuels such as natural gas or syngas (from coal gasification systems) with complete CO2 separation at a high-efficiency and zero atmospheric emissions. This semi-closed cycle produces sequestration-ready/pipeline quality CO2 by-product, and thus eliminates the need for additional CO2-capture system. The Coal-fueled Allam cycle is targeted to deliver between 51-52% net efficiency (lower heating value) for coal gasification. In this study, the expected energetic efficiency is verified by simulating the system in Ebsilon professional software and the result showed that the net efficiency of the simulated coal-fired plant is 30.7%, which is significantly lower than the targeted value. The lower efficiency maybe as a result of the missing heat ...

E3S Web of Conferences

Advanced exergy-based analyses provide the information for potential of improvement of energy- co... more Advanced exergy-based analyses provide the information for potential of improvement of energy- conversion systems from exergetic, economic and environmental point of view. These analyses are applied to Cryogenic-based Energy Storage (CES) also known as Liquid Air Energy Storage (LAES). Advantages such as (a) lack of geographical restrictions, (b) low environmental impact and the fact that it is (c) based on mature technology, drive further the research on this energy storage system. An adiabatic LAES system charged with Heylandt liquefaction of air process is analysed. Parameters such as exergy destruction, investment cost, cost associated with the exergy destruction, as well as the environmental impact associated with the thermodynamic irreversibilities are split into avoidable/unavoidable and endogenous/exogenous parts. Aspen Plus® software was used to simulate the LAES system and Engineering Equation Solver was used to conduct the conventional and advanced exergy-based analyses. ...

Entropy

The purpose of this research is to evaluate a transcritical heat-driven compression refrigeration... more The purpose of this research is to evaluate a transcritical heat-driven compression refrigeration machine with CO2 as the working fluid from thermodynamic and economic viewpoints. Particular attention was paid to air-conditioning applications under hot climatic conditions. The system was simulated by Aspen HYSYS® (AspenTech, Bedford, MA, USA) and optimized by automation based on a genetic algorithm for achieving the highest exergetic efficiency. In the case of producing only refrigeration, the scenario with the ambient temperature of 35 °C and the evaporation temperature of 5 °C showed the best performance with 4.7% exergetic efficiency, while the exergetic efficiency can be improved to 22% by operating the system at the ambient temperature of 45 °C and the evaporation temperature of 5 °C if the available heating capacity within the gas cooler is utilized (cogeneration operation conditions). Besides, an economic analysis based on the total revenue requirement method was given in det...

Energies

State-of-the-art thermodynamic simulation of energy conversion processes requires proprietary sof... more State-of-the-art thermodynamic simulation of energy conversion processes requires proprietary software. This article is an attempt to refute this statement. Based on object-oriented programming a simulation and exergy analysis of a combined cycle gas turbine is carried out in a free and open-source framework. Relevant basics of a thermodynamic analysis with exergy-based methods and necessary fluid property models are explained. Thermodynamic models describe the component groups of a combined heat and power system. The procedure to transform a physical model into a Python-based simulation program is shown. The article contains a solving algorithm for a precise gas turbine model with sophisticated equations of state. As an example, a system analysis of a combined cycle gas turbine with district heating is presented. Herein, the gas turbine model is validated based on literature data. The exergy analysis identifies the thermodynamic inefficiencies. The results are graphically presented...

Energies

Cryogenics-based energy storage (CES) is a thermo-electric bulk-energy storage technology, which ... more Cryogenics-based energy storage (CES) is a thermo-electric bulk-energy storage technology, which stores electricity in the form of a liquefied gas at cryogenic temperatures. The charging process is an energy-intensive gas liquefaction process and the limiting factor to CES round trip efficiency (RTE). During discharge, the liquefied gas is pressurized, evaporated and then super-heated to drive a gas turbine. The cold released during evaporation can be stored and supplied to the subsequent charging process. In this research, exergy-based methods are applied to quantify the effect of cold storage on the thermodynamic performance of six liquefaction processes and to identify the most cost-efficient process. For all liquefaction processes assessed, the integration of cold storage was shown to multiply the liquid yield, reduce the specific power requirement by 50–70 % and increase the exergetic efficiency by 30–100 %. The Claude-based liquefaction processes reached the highest exergetic ...

Integrated Environmental Assessment and Management

Global natural gas demand is expected to continue to grow strongly. Liquefied Natural Gas (LNG) m... more Global natural gas demand is expected to continue to grow strongly. Liquefied Natural Gas (LNG) mainly consists of methane after the liquefaction process which takes 600 times less volume and this issue makes Natural Gas economical to be transported by ship. As LNG offers greater trade flexibility than pipeline transport, the investigation of LNG technologies was one of the most significant issues of the years. This challenge is growing by increasing the demand of LNG and expecting its lower unit cost. The growth in the LNG market and the need to improve process efficiencies under different working conditions resulted in the implementation of new liquefaction technologies. C3MR process is one of the most popular technologies of LNG production using a simple propane refrigeration loop for natural gas pre-cooling. The liquefaction and sub-cooling processes are both within liquefaction block in this technology. In order to liquefy the huge capacity of natural gas a decision of separating Sub-Cooling block as an extra independent block came to industry. The purpose of this parer is to evaluate the C3MR process by introducing the separate Sub-Cooling block at the end of this simulated block. The thermodynamic results are obtained from the simulation made with the Aspen Plus software. The results of the energetic and exergetic analysis are presented to compare all evaluated possibilities of this new technology. The conventional exergetic analysis of the this process evaluated in this thesis has provided useful information about the inefficiencies in the components and the overall system.

Handbook of Research on Advances and Applications in Refrigeration Systems and Technologies, 2015

Encyclopedia of Physical Science and Technology, 2003

Progress in Energy and Combustion Science, 1993

This article discusses the development, state-of-the-art and applications of exergy analysis and ... more This article discusses the development, state-of-the-art and applications of exergy analysis and thermoeconomics (exergoeconomics). The latter is a relatively new method that combines exergy with conventional concepts from engineering economics to evaluate and optimize the design and performance of energy systems. This paper is written mainly for the person interested in applying tbermoeconomics to an energy system. It reviews the history of exergy analysis and thermoeconomics, the performance evaluation of an energy system from the viewpoints of the second law of thermodynamics and thermoeconomics as well as applications of thermoeconomic optimization techniques.

Chemical Engineering & Technology, 1996

Energy Conversion and Management, 2015

ABSTRACT Exergetic and exergoeconomic analyses are often used to evaluate the performance of ener... more ABSTRACT Exergetic and exergoeconomic analyses are often used to evaluate the performance of energy systems from the thermodynamic and economic points of view. While a conventional exergetic analysis can be used to recognize the sources of inefficiencies, the so-called advanced exergy-based analysis is convenient for identifying the real potential for thermodynamic improvements and the system component interactions by splitting the exergy destruction and the total operating cost within each component into endogenous/exogenous and unavoidable/avoidable parts. In this study for the first time an advanced exergoeconomic analysis is applied to a gas-engine-driven heat pump (GEHP) drying system used in food drying for evaluating its performance along with each component. The advanced exergoeconomic analysis shows that the unavoidable part of the exergy destruction cost rate within the components of the system is lower than the avoidable part. The most important components based on the total avoidable costs are drying ducts, the condenser and the expansion valve. The inefficiencies within the condenser could particularly be improved by structural improvements of the whole system and the remaining system components. Finally, it can be concluded that the internal design changes play a more essential role in determining the cost of each component.

Energies

This is a review of the concepts of purpose, direction, and objective in the discipline of thermo... more This is a review of the concepts of purpose, direction, and objective in the discipline of thermodynamics, which is a pillar of physics, natural sciences, life science, and engineering science. Reviewed is the relentless evolution of this discipline toward accounting for evolutionary design with direction, and for establishing the concept of purpose in methodologies of modeling, analysis, teaching, and design optimization. Evolution is change after change toward flow access, with direction in time, and purpose. Evolution does not have an ‘end’. In thermodynamics, purpose is already the defining feature of methods that have emerged to guide and facilitate the generation, distribution, and use of motive power, heating, and cooling: thermodynamic optimization, exergy-based methods (i.e., exergetic, exergoeconomic, and exergoenvironmental analysis), entropy generation minimization, extended exergy, environomics, thermoecology, finite time thermodynamics, pinch analysis, animal design, g...

Entropy

The transition towards higher shares of electricity generation from renewable energy sources is s... more The transition towards higher shares of electricity generation from renewable energy sources is shown to be significantly slower in developing countries with low-cost fossil fuel resources. Integrating conventional power plants with concentrated solar power may facilitate the transition towards a more sustainable power production. In this paper, a novel natural gas-fired integrated solar combined-cycle power plant was proposed, evaluated, and optimized with exergy-based methods. The proposed system utilizes the advantages of combined-cycle power plants, direct steam generation, and linear Fresnel collectors to provide 475 MW baseload power in Aswan, Egypt. The proposed system is found to reach exergetic efficiencies of 50.7% and 58.1% for day and night operations, respectively. In economic analysis, a weighted average levelized cost of electricity of 40.0 $/MWh based on the number of day and night operation hours is identified. In exergoeconomic analysis, the costs of thermodynamic ...

E3S Web of Conferences

Allam cycle is a novel cycle that capitalizes on the unique thermodynamic properties of supercrit... more Allam cycle is a novel cycle that capitalizes on the unique thermodynamic properties of supercritical CO2 and the advantages of oxy-combustion for power generation. It is a high-pressure supercritical carbon dioxide cycle designed to combust fossil fuels such as natural gas or syngas (from coal gasification systems) with complete CO2 separation at a high-efficiency and zero atmospheric emissions. This semi-closed cycle produces sequestration-ready/pipeline quality CO2 by-product, and thus eliminates the need for additional CO2-capture system. The Coal-fueled Allam cycle is targeted to deliver between 51-52% net efficiency (lower heating value) for coal gasification. In this study, the expected energetic efficiency is verified by simulating the system in Ebsilon professional software and the result showed that the net efficiency of the simulated coal-fired plant is 30.7%, which is significantly lower than the targeted value. The lower efficiency maybe as a result of the missing heat ...

E3S Web of Conferences

Advanced exergy-based analyses provide the information for potential of improvement of energy- co... more Advanced exergy-based analyses provide the information for potential of improvement of energy- conversion systems from exergetic, economic and environmental point of view. These analyses are applied to Cryogenic-based Energy Storage (CES) also known as Liquid Air Energy Storage (LAES). Advantages such as (a) lack of geographical restrictions, (b) low environmental impact and the fact that it is (c) based on mature technology, drive further the research on this energy storage system. An adiabatic LAES system charged with Heylandt liquefaction of air process is analysed. Parameters such as exergy destruction, investment cost, cost associated with the exergy destruction, as well as the environmental impact associated with the thermodynamic irreversibilities are split into avoidable/unavoidable and endogenous/exogenous parts. Aspen Plus® software was used to simulate the LAES system and Engineering Equation Solver was used to conduct the conventional and advanced exergy-based analyses. ...

Entropy

The purpose of this research is to evaluate a transcritical heat-driven compression refrigeration... more The purpose of this research is to evaluate a transcritical heat-driven compression refrigeration machine with CO2 as the working fluid from thermodynamic and economic viewpoints. Particular attention was paid to air-conditioning applications under hot climatic conditions. The system was simulated by Aspen HYSYS® (AspenTech, Bedford, MA, USA) and optimized by automation based on a genetic algorithm for achieving the highest exergetic efficiency. In the case of producing only refrigeration, the scenario with the ambient temperature of 35 °C and the evaporation temperature of 5 °C showed the best performance with 4.7% exergetic efficiency, while the exergetic efficiency can be improved to 22% by operating the system at the ambient temperature of 45 °C and the evaporation temperature of 5 °C if the available heating capacity within the gas cooler is utilized (cogeneration operation conditions). Besides, an economic analysis based on the total revenue requirement method was given in det...

Energies

State-of-the-art thermodynamic simulation of energy conversion processes requires proprietary sof... more State-of-the-art thermodynamic simulation of energy conversion processes requires proprietary software. This article is an attempt to refute this statement. Based on object-oriented programming a simulation and exergy analysis of a combined cycle gas turbine is carried out in a free and open-source framework. Relevant basics of a thermodynamic analysis with exergy-based methods and necessary fluid property models are explained. Thermodynamic models describe the component groups of a combined heat and power system. The procedure to transform a physical model into a Python-based simulation program is shown. The article contains a solving algorithm for a precise gas turbine model with sophisticated equations of state. As an example, a system analysis of a combined cycle gas turbine with district heating is presented. Herein, the gas turbine model is validated based on literature data. The exergy analysis identifies the thermodynamic inefficiencies. The results are graphically presented...

Energies

Cryogenics-based energy storage (CES) is a thermo-electric bulk-energy storage technology, which ... more Cryogenics-based energy storage (CES) is a thermo-electric bulk-energy storage technology, which stores electricity in the form of a liquefied gas at cryogenic temperatures. The charging process is an energy-intensive gas liquefaction process and the limiting factor to CES round trip efficiency (RTE). During discharge, the liquefied gas is pressurized, evaporated and then super-heated to drive a gas turbine. The cold released during evaporation can be stored and supplied to the subsequent charging process. In this research, exergy-based methods are applied to quantify the effect of cold storage on the thermodynamic performance of six liquefaction processes and to identify the most cost-efficient process. For all liquefaction processes assessed, the integration of cold storage was shown to multiply the liquid yield, reduce the specific power requirement by 50–70 % and increase the exergetic efficiency by 30–100 %. The Claude-based liquefaction processes reached the highest exergetic ...

Integrated Environmental Assessment and Management