Advanced Exergoeconomic Analysis of a Refrigeration Machine: Part 2—Improvement

2011 ◽  
Author(s):  
T. Morosuk ◽  
G. Tsatsaronis
Keyword(s):  
Machine Part ◽  
Decision Variables ◽  
Exergoeconomic Analysis ◽  
The Cost ◽  
Refrigeration Machine

In the first part of the paper, the advanced exergy-based analyses are applied to an air refrigeration machine. In this part, we demonstrate that the information obtained in the first part can be used to modify the values of the decision variables to reduce the cost of the final product (cold) of the overall system.

Advanced Exergoeconomic Analysis of a Refrigeration Machine: Part 1—Methodology and First Evaluation

2011 ◽  
Author(s):  
T. Morosuk ◽  
G. Tsatsaronis
Keyword(s):  
System Component ◽  
Formation Processes ◽  
Real Potential ◽  
Decision Variables ◽  
Energy Conversion System ◽  
Exergoeconomic Analysis ◽  
The Cost ◽  
Important System ◽  
Refrigeration Machine

An exergoeconomic analysis identifies the location, magnitude and sources of thermodynamic inefficiencies and costs in an energy conversion system. This information is used for improving the thermodynamic and the economic performance and for comparing various systems. A conventional exergy-based analysis does not consider the interactions among the components of a system nor the real potential for improving the system. These shortcomings can be addressed and the quality of the conclusions obtained from an exergoeconomic evaluation is improved, when for each important system component the values of exergy destruction and costs are split into endogenous/exogenous and avoidable/unavoidable parts. We call the analyses resulting from such splittings advanced exergy-based analyses. The paper demonstrates how an advanced exergoeconomic analysis provides the user with information on the formation processes of thermodynamic inefficiencies and costs and with suggestions for their minimization. In the first part of the paper, the advanced exergy-based analyses are applied to an air refrigeration machine. In the second part of the paper, we demonstrate that the information obtained in the first part can be used to modify the values of the decision variables to reduce the cost of the final product (cold) of the overall system.

Exergoeconomic analysis of renewable multi-generation system

2020 ◽  
pp. 99-111
Author(s):  
Vontas Alfenny Nahan ◽  
Audrius Bagdanavicius ◽  
Andrew McMullan
Keyword(s):  
Capital Investment ◽  
Combined Cycle ◽  
Asian Countries ◽  
Generation System ◽  
Integrated Gasification Combined Cycle ◽  
Heating And Cooling ◽  
Integrated Gasification ◽  
Exergoeconomic Analysis ◽  
Main Components ◽  
The Cost

In this study a new multi-generation system which generates power (electricity), thermal energy (heating and cooling) and ash for agricultural needs has been developed and analysed. The system consists of a Biomass Integrated Gasification Combined Cycle (BIGCC) and an absorption chiller system. The system generates about 3.4 MW electricity, 4.9 MW of heat, 88 kW of cooling and 90 kg/h of ash. The multi-generation system has been modelled using Cycle Tempo and EES. Energy, exergy and exergoeconomic analysis of this system had been conducted and exergy costs have been calculated. The exergoeconomic study shows that gasifier, combustor, and Heat Recovery Steam Generator are the main components where the total cost rates are the highest. Exergoeconomic variables such as relative cost difference (r) and exergoeconomic factor (f) have also been calculated. Exergoeconomic factor of evaporator, combustor and condenser are 1.3%, 0.7% and 0.9%, respectively, which is considered very low, indicates that the capital cost rates are much lower than the exergy destruction cost rates. It implies that the improvement of these components could be achieved by increasing the capital investment. The exergy cost of electricity produced in the gas turbine and steam turbine is 0.1050 £/kWh and 0.1627 £/kWh, respectively. The cost of ash is 0.0031 £/kg. In some Asian countries, such as Indonesia, ash could be used as fertilizer for agriculture. Heat exergy cost is 0.0619 £/kWh for gasifier and 0.3972 £/kWh for condenser in the BIGCC system. In the AC system, the exergy cost of the heat in the condenser and absorber is about 0.2956 £/kWh and 0.5636 £/kWh, respectively. The exergy cost of cooling in the AC system is 0.4706 £/kWh. This study shows that exergoeconomic analysis is powerful tool for assessing the costs of products.

Optimal Charging Management of Microgrid-Integrated Electric Vehicles

2022 ◽  
pp. 133-155
Author(s):  
Giulio Ferro ◽  
Riccardo Minciardi ◽  
Luca Parodi ◽  
Michela Robba
Keyword(s):  
Electric Vehicles ◽  
Discrete Event ◽  
Time Discretization ◽  
Small Time ◽  
Storage Element ◽  
Charging Station ◽  
Decision Variables ◽  
Discretization Step ◽  
Definition Of ◽  
The Cost

The relevance of electric vehicles (EVs) is increasing along with the relative issues. The definition of smart policies for scheduling the EVs charging process represents one of the most important problems. A discrete-event approach is proposed for the optimal scheduling of EVs in microgrids. This choice is due to the necessity of limiting the number of the decision variables, which rapidly grows when a small-time discretization step is chosen. The considered optimization problem regards the charging of a series of vehicles in a microgrid characterized by renewable energy source, a storage element, the connection to the main grid, and a charging station. The objective function to be minimized results from the weighted sum of the cost for purchasing energy from the external grid, the weighted tardiness of the services provided, and a cost related to the occupancy of the socket. The approach is tested on a real case study.

scholarly journals Layout Optimization Process to Minimize the Cost of Energy of an Offshore Floating Hybrid Wind–Wave Farm

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 139 ◽  
Author(s):  
Jorge Izquierdo-Pérez ◽  
Bruno M. Brentan ◽  
Joaquín Izquierdo ◽  
Niels-Erik Clausen ◽  
Antonio Pegalajar-Jurado ◽  
...  
Keyword(s):  
Wind Wave ◽  
Pso Algorithm ◽  
Calculation Model ◽  
Optimization Process ◽  
Cost Of Energy ◽  
Decision Variables ◽  
Decision Making Processes ◽  
A Site ◽  
The Cost ◽  
Wave Farm

Offshore floating hybrid wind and wave energy is a young technology yet to be scaled up. A way to reduce the total costs of the energy production process in order to ensure competitiveness in the sustainable energy market is to maximize the farm’s efficiency. To do so, an energy generation and costs calculation model was developed with the objective of minimizing the technology’s Levelized Cost of Energy (LCOE) of the P80 hybrid wind-wave concept, designed by the company Floating Power Plant A/S. A Particle Swarm Optimization (PSO) algorithm was then implemented on top of other technical and decision-making processes, taking as decision variables the layout, the offshore substation position, and the export cable choice. The process was applied off the west coast of Ireland in a site of interest for the company, and after a quantitative and qualitative optimization process, a minimized LCOE was obtained. It was then found that lower costs of ~73% can be reached in the short-term, and the room for improvement in the structure’s design and materials was highlighted, with an LCOE reduction potential of up to 32%. The model serves usefully as a preliminary analysis. However, the uncertainty estimate of 11% indicates that further site-specific studies and measurements are essential.

Exergoeconomic Analysis of Intercooled, Reheated and Recuperated Gas Turbine Cycles With Air Film Blade Cooling

2018 ◽  
Author(s):  
Waleed El-Damaty ◽  
Mohamed Gadalla
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Turbine Blades ◽  
Cost Calculation ◽  
Theory Approach ◽  
Cooling Systems ◽  
Thermodynamic Performance ◽  
Exergoeconomic Analysis ◽  
The Cost

For many years, thermodynamic analysis was considered to be the principal tool that is used to predict the performance of a power plant. Recently, the environmental effect and the cost of power plants have been considered as important as the thermodynamic performance in design of power plants. Thus, researchers started to adopt a relevantly new approach called the exergoeconomic analysis which combines the thermodynamic technicalities as well as the economic analysis to design power plants. The exergoeconomic analysis provides crucial information that helps in foreseeing not only the thermodynamic performance but also all economic variables related to power plants. Increasing the efficiency of the power plant has been the major concern in power plants. Thus, the global approach of reaching high turbine inlet temperatures to improve the efficiency of power plants, has exposed the turbine blades to some serious problems. Thereby, cooling the turbine blades has become an important aspect that needs to be taken care of during the power plant operation. In this paper, a cooled gas turbine with intercooler, recuperator and reheater is adopted where it is incorporated with a cooling system. An exergoeconomic analysis accompanied by a sensitivity analysis was performed on the gas turbine cycle to determine the exergo-economic factor and the relative cost difference in addition to study the effect of different variables on the gas turbine thermal and exergetic efficiency, net specific work and the total cost rate. Average cost theory approach was adopted from various thermo-economic methodologies to determine the cost calculation during this investigation. The results showed a reduction in the total coolant mass flow rate in the base case where no cooling systems are integrated from 3.349 kg/s to 3.01 kg/s, 2.995 kg/s and 2.977 kg/s in the case of integrating the cooling systems triple stage Maisotsenko desiccant, triple stage precooling Maisotsenko desiccant and triple stage extra cooling Maisotsenko desiccant, respectively. Accordingly, the thermal efficiency has increased to reach 52.69%, 52.89% and 53.12% by the integration of TS-MD, TS-PMD and TS-EMD cooling systems, respectively.

Exergoeconomic Analysis of a Combined Cycle of Three Levels of Pressure

2016 ◽  
Author(s):  
Edgar Vicente Torres González ◽  
Raúl Lugo-Leyte ◽  
Martín Salazar-Pereyra ◽  
Miguel Toledo Velázquez ◽  
Helen Denise Lugo-Méndez ◽  
...  
Keyword(s):  
Power Plant ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Systematic Approach ◽  
Combined Cycle ◽  
Exergetic Efficiency ◽  
Steam Generators ◽  
Combined Cycle Power Plant ◽  
Exergoeconomic Analysis ◽  
The Cost

This paper presents an exergoeconomic analysis of the combined cycle power plant Tuxpan II located in Mexico. The plant is composed of two identical modules conformed by two gas turbines generating the required work and releasing the hot exhaust gases in two heat recovery steam generators. These components generate steam at three different pressure levels, used to produce additional work in one steam turbine. The productive structure of the considered system is used to visualize the cost formation process as well as the productive interaction between their components. The exergoeconomic analysis is pursued by 1) carrying out a systematic approach, based on the Fuel-Product methodology, in each component of the system; and 2) generating a set of equations, which allows compute the exergetic and exergoeconomic costs of each flow. The thermal and exergetic efficiency of the two gas turbines delivering 278.4 MW are 35.16% and 41.90% respectively. The computed thermal efficiency of the steam cycle providing 80.96 MW is 43.79%. The combined cycle power plant generates 359.36 MW with a thermal and exergetic efficiency of 47.27% and 54.10% respectively.

Advanced Exergoeconomic Evaluation and Its Application to Compression Refrigeration Machines

2007 ◽  
Author(s):  
George Tsatsaronis ◽  
Tatiana Morosuk
Keyword(s):  
Energy Conversion ◽  
Exergy Analysis ◽  
System Component ◽  
Exergy Destruction ◽  
Conversion System ◽  
Investment Cost ◽  
Energy Conversion System ◽  
The Cost ◽  
Refrigeration Machine

Splitting the exergy destruction within each component of an energy conversion system into endogenous/exogenous and unavoidable/avoidable parts enhances an exergy analysis and improves the quality of the conclusions obtained from the analysis. The potential for improving each system component is identified and priorities, according to which the design of components should be modified, are established. We call this detailed exergy analysis advanced exergy analysis. For improving the cost effectiveness of an energy conversion system, splitting the investment cost into endogenous/exogenous and unavoidable/avoidable parts is also helpful. The designer should focus on the avoidable thermodynamic inefficiencies (exergy destruction), their costs and the avoidable investment costs. The paper discusses the calculation of these costs in general and the resulting advanced exergoeconomic evaluation that is based on the avoidable endogenous and the avoidable exogenous values for exergy destruction, cost of exergy destruction and investment cost. An application of this methodology to a compression refrigeration machine is presented.

Exergoeconomic Analysis of an Advanced Zero Emission Plant

2009 ◽  
Author(s):  
F. Petrakopoulou ◽  
G. Tsatsaronis ◽  
T. Morosuk
Keyword(s):  
Co2 Capture ◽  
Chemical Absorption ◽  
Reference Case ◽  
Efficient Combustion ◽  
Energy Conversion Systems ◽  
Zero Emission ◽  
Cost Calculations ◽  
Exergoeconomic Analysis ◽  
Free Environment ◽  
The Cost

Exergy-based methods are reliable means for the comparison and the evaluation of the operation of energy conversion systems. In this paper, the Advanced Zero Emission Plant, a plant that performs combustion in a nitrogen-free environment (oxy-fuel combustion) is presented, compared to a reference plant (without CO2 capture) and evaluated based on an exergoeconomic analysis. A variation of the oxy-fuel plant with a lower CO2 capture percentage (85%) is also presented in order to (1) evaluate the influence of CO2 capture on a plant’s overall performance and cost, and (2) enable the comparison with other conventional methods, such as post-combustion with chemical absorption that also performs CO2 capture with lower effectiveness. When compared to the reference case, the oxy-fuel plants achieve a minimal decrease in exergetic efficiency, essentially due to their more efficient combustion processes. Cost calculations reveal that the membrane used for the oxygen production in the oxy-fuel plants is their main expenditure. Nonetheless, the cost of electricity and the cost of CO2 avoided for these plants are calculated to be competitive with chemical absorption.

scholarly journals Using system simulation to search for the optimal multi-ordering policy for perishable goods

2019 ◽  
Vol 7 (1) ◽  
pp. 49
Author(s):  
Y.C. Huang ◽  
X.Y. Chang ◽  
Y.A. Ding
Keyword(s):  
Stochastic Demand ◽  
Optimal Solution ◽  
Practical Applications ◽  
Ordering Policy ◽  
Perishable Goods ◽  
Decision Variables ◽  
Proposed Model ◽  
The Cost ◽  
Optimal Ordering ◽  
Computerized System

<p>This paper explores the possibility that perishable goods can be ordered several times in a single period after considering the cost of Marginal contribution, Marginal loss, Shortage, and Purchasing under stochastic demand. In order to determine the optimal ordering quantity to improve the traditional newsvendor and maximize the total expected profits, and then sensitivity analysis is taken to realize the influence of the parameters on total expected profits and decision variables respectively. In addition, this paper designed a multi-order computerized system with Monte Carlo method to solve the optimal solution under stochastic demand. Based on numerical examples, this paper verified the feasibility and efficiency of the proposed model. Finally, several specific conclusions are drawn for practical applications and future studies.</p>

Optimization of a two-echelon supply chain with random demand and random defect rate under strict carbon cap policy

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Arindam Ghosh
Keyword(s):  
Supply Chain ◽  
Sensitivity Analyses ◽  
Mixed Integer ◽  
Defective Items ◽  
Content Type ◽  
Defect Rate ◽  
Decision Variables ◽  
Minlp Problem ◽  
Regulatory Bodies ◽  
The Cost

PurposeThe yield of defective items and emissions of greenhouse gases in supply chains are areas of concern. Organizations try to reduce the yield defective items and emissions. In this paper, a constrained optimization model is developed with consideration of the yield of defective items and strict carbon cap policy simultaneously and then optimized. Further, sensitivity analyses have been carried out to draw different managerial insights. Precisely, we have tried to address the following research questions: (1) how to optimize the cost for a two-echelon supply chain considering yield of defective items and strict carbon cap policy, (2) how the total expected cost and total expected emissions act with changing parameters.Design/methodology/approachThe mathematical modeling approach has been adopted to develop a model and further optimized it with optimization software. Costs and emissions from different areas of a supply chain have been derived and then the total cost and total emissions have been formulated mathematically. One constrained mixed-integer nonlinear programming (MINLP) problem has been formulated and solved considering emissions-related, velocity and production related-constraints. Further, different sensitivity analyses have been derived to draw some managerial insights.FindingsIn this paper, many decision variables have been calculated with a set of basic values of other parameters. It has been found that both cost and emissions can be controlled by controlling different parameters. It has been also found that some parameters have very little or no influence either on cost or emissions. In most cases, originations may exhaust the given limit of carbon cap to optimize their costs.Originality/valueIn spite of my sincere efforts, no paper has been found that has considered the yield of defective items and strict carbon cap policy simultaneously. In this paper, it is assumed that both demand and defect rates are random in nature. The model, presented in this paper may give insights to develop different supply chain models with consideration of both defective items and strict carbon cap policy. Sensitivity analyses, drawn in this paper may give deep insights to managers and carbon regulatory bodies.

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