Advanced Exergoeconomic Analysis Research Articles

Advanced exergoeconomic analysis and mathematical modelling of the natural gas fired gas turbine unit used for industrial cogeneration system

In this study, mathematical model of advanced exergoeconomic analysis (ADEXEC) basing on advanced specific exergy cost (ADSPECO) and advanced exergy-cost-energy-mass (EXCEM) (ADEXCEM) methods are applied to the industrial cogeneration system (COGEN) which consists of natural gas fired gas turbine unit (with combustion chamber (CC), turbine (GT) and air compressor (AC)), pipe line (PL), wall (WD) and ground (GD) tile dryers under the dead state conditions of 10 °C, 15 °C, 20 °C, 25 °C and 30 °C. According to ADSPECO analysis; although CC ($6.97/GJ) has the lowest unit fuel exergy cost among the components, it has the highest exergy destruction cost rate ($252,391/hour at 30 °C) due to its high exergy destruction value. Although more than 40 % of the exergy destruction cost rate in the COGEN system is detected in CC, WD (105.541 $/h at 30 °C) and GD (107.499 $/h at 30 °C) which together account for more than 67 % of COGEN's avoidable exergy destruction are understood to be the first components to focus on. The fact that the exergy destruction cost rates of all components except PL is higher than the exogenous part of the endogenous part at all dead state temperatures reveals the weakness of the relationship between the components.

Advanced exergy and advanced exergoeconomic analyses of the partial heating supercritical CO2 power cycle for waste heat recovery

Advanced exergy and advanced exergoeconomic analyses of the partial heating supercritical CO2 power cycle for waste heat recovery

Advanced exergo-economic analysis of an advanced adiabatic compressed air energy storage system with the modified productive structure analysis method and multi-objective optimization study

In this study, conventional and advanced exergy/exergo economic analyses of an advanced adiabatic compressed air energy storage system (AA-CAES) system with a power output of 6 MW were performed. In addition, sensitivity analysis and multi-objective optimization study of the proposed system were also carried out. For the first time in the literature, advanced exergo-economic analysis was applied to the AA-CAES system with the Modified Productive Structure Analysis (MOPSA) method, and a new parameter was introduced as a performance criterion for this method. As a result of the study, the system's exergy efficiencies were found to be 54.51 % and 77 %, respectively, according to the conventional and advanced exergy analyses of the system. According to the conventional exergy analysis, the first three system components that should be given priority are the wind turbine (WT), the regulator (REG), and the heat exchangers-3 (HE-3), respectively. According to the advanced exergy analysis, this order changes as WT, the compressor-1 (C-1), and the compressor-2 (C-2). 40 % of the system's exergy destruction and exergy destruction cost rates are avoidable endogenous. This value shows the improvement potential of the system. As a result of the multi-objective optimization study, the modified exergy efficiency was found to be 94.58 %. The average unit product-exergy destruction cost was 59.51 $/GJ; these values were 22.83 % and 1.6 % improvement, respectively, compared to the base case.

Energy and advanced exergoeconomic analysis of a novel ejector-based CO2 refrigeration system and its optimization for supermarket application in warm climates

Energy and advanced exergoeconomic analysis of a novel ejector-based CO2 refrigeration system and its optimization for supermarket application in warm climates

Advanced exergy and exergo-economic analyses of an advanced adiabatic compressed air energy storage system, part 2: Parametric study and optimization

In this study, parametric analysis and multi-objective optimization of the advanced adiabatic compressed air energy storage system (AA-CAES) were performed. Non-dominated Sorting Genetic Algorithm (NSGA-II) method was used in the multi-objective optimization study. In the optimization study, objective functions were determined in the conventional and advanced exergy/exergo-economic analyses concept. In the optimization study in the concept of advanced exergo-economic analyses, a new performance criterion that is not in the literature was determined and the results were confirmed by conventional exergo-economic analyses. In this study, the modified total unit product cost, which is given as the new performance criterion, is defined on the basis of avoidable feed exergy cost rate and avoidable investment cost rate. This shows the potential to be improved in the cost of the system and gives more detailed information than the total unit product cost in conventional exergo-economic analysis. As a result of the optimization study, the total unit product cost and the exergy efficiency of the system were found to be 162.9 $/day and 64.3%, respectively for the conventional exergy/exergo-economic analyses concept. For the advanced exergy/exergo-economic analyses concept, the modified total unit product cost and the modified exergy efficiency of system were found to be 103.5 $/day and 91.9 %. The exergy efficiency and the total unit product cost improved by 16.48 % and 3.55 %, respectively, with the optimization study according to the basic case of the overall system. With the parametric study, the increase in the efficiency of the wind turbine affected the exergy destruction rate more than the other system components. While the effect of the increase in the efficiency of the turbines on the exergy destruction cost rate of the system is greater than the other system components, the system component that most affects the cost rate of the system is the compressors.

Advanced exergoeconomics of a steam power plant based on double-tier splitting of exergy destruction rates

The advanced exergy and exergoeconomic analysis methodologies excel over their conventional counterparts by quantifying endogenous/exogenous exergy destruction rates and related costs that reveal the interactions among system components. By quantifying avoidable/unavoidable losses, they also reveal the potentials for component improvements that are practically achievable. These data are imperative for improving the cost-effectiveness of thermal systems. This paper presents the performances of a complex gas-fired power plant obtained via an advanced exergoeconomic analysis. The study advances existing studies by undertaking second-tier splitting of exergy destruction cost rates and associated investment cost rates to determine avoidable endogenous, unavoidable endogenous, avoidable exogenous, and unavoidable exogenous cost rates of the plant’s components. Component exergy destruction cost rates were found to be predominantly unavoidable, while most of the component investment cost rates were avoidable. Except for the low pressure heater 3, exergy destruction cost rates are endogenous in all the plant components, contributing 84% of overall cost rates. The proportions of exergy destruction cost rates and investment cost rates of the plant that are avoidable endogenous were 21% and 28% respectively, while the respective portions that are avoidable exogenous were 4% and 27%. Furthermore, it was shown that as much as 96.3% improvements in overall plant cost-effectiveness were achievable by eliminating avoidable endogenous exergy destruction cost rates and investment cost rates for major components of the plant.

Advanced Exergoeconomic Assessment of CO2 Emissions, Geo-Fluid and Electricity in Dual Loop Geothermal Power Plant

Binary geothermal power plants (GPPs) are mostly encountered in geothermal fields with medium and low temperatures. The design and operation of dual binary GPPs can be difficult due to the geothermal fluid properties. This affects their performance and feasibility. Thermoeconomics are essential elements for the design and operation of the GPPs. In this study, advanced exergoeconomic analysis is applied to a true dual binary GPP (as a case study) to further evaluate it from performance and economic perspectives. In analysis, the specific exergy cost (SPECO) method is used. Then, some specific indicators are presented to evaluate the performance and economics of the GPP. Thus, technical and economic solutions have been developed in the design and operation stages through the analysis. The results of the study indicated that the total operating cost of 1218 USD/h could be reduced to 186 USD/h by improving the operating conditions. This corresponds to an 85% decrease. The cost per electricity generated, cost per geothermal energy input, and cost per CO2 emission of the GPP are determined as 0.049 USD/kWh, 5.3 USD/GJ, and 0.13 USD/kg, respectively. As a result, while the savings potential of the GPP is 15%, it can result in a 15% reduction in CO2 emission cost.

Evaluation of small-scale liquefied natural gas (SSLNG) processes: advanced exergoeconomic analysis

Evaluation of small-scale liquefied natural gas (SSLNG) processes: advanced exergoeconomic analysis

Conventional and Advanced Exergy and Exergoeconomic Assessment of an Optimized System Consisting of Kalina and Organic Rankine Cycles for Waste Heat Recovery

Abstract The use of different technologies to recover the waste heat from various sources is receiving a wide currency worldwide. The current study proposes a Kalina-organic Rankine cycle (ORC)-based system in order to make use of the exhaust gas and the jacket cooling water of an existing diesel engine. First, the system is optimized to generate maximum power. Then, the optimum system is subjected to both conventional and advanced analyses investigating its exergy and exergoeconomic aspects. Hence, the real sources of inefficiency and chances of enhancement are revealed. The system can produce 69.7 kW power with energy and exergy efficiencies of 22.3% and 59.2%, respectively. The Kalina steam generator has the most irreversibility share in the system; however, when it comes to the real potential of improvement, the Kalina turbine ranks the first that can benefit the entire system. Moreover, the results of both conventional and advanced exergoeconomic analyses indicate the Kalina turbine is the most highlighted component that both needs and can be improved in terms of cost rates. In the end, a comparison between the different results and approaches is made to summarize the results.

Advanced exergy and exergo-economic analyses of a novel combined power system using the cold energy of liquefied natural gas

In this study, a new combined power system using the cold energy of liquefied natural gas (LNG) is designed. Conventional and advanced exergy and exergo-economic analyses of the system were made. According to the research in the literature, for the first time, advanced exergo-economic analysis was applied to a combined power system using the cold energy of LNG with the Modified Productive Structure Analysis (MOPSA) method. 23% of the exergy destruction and exergy destruction cost rate of the combined system is avoidable. In both conventional and advanced exergy analysis, the highest exergy destruction and cost rate were found in the parabolic solar collector. In addition, as a result of the analyses, it has been seen that the most effective main system components with the potential to improve the performance of the combined system are the parabolic solar collector, the turbine in direct expansion cycle and the turbine in the Organic Rankine cycle, respectively. The study revealed that there is potential to improve the performance of the proposed combined power system.

Conventional and Advanced Exergoeconomic Analysis of a Compound Ejector-Heat Pump for Simultaneous Cooling and Heating

This work focused on a compound PV/T waste heat driven ejector-heat pump system for simultaneous data centre cooling and waste heat recovery for district heating. The system uses PV/T waste heat as the generator’s heat source, acting with the vapour generated in an evaporative condenser as the ejector drive force. Conventional and advanced exergy and advanced exergoeconomic analyses are used to determine the cause and avoidable degree of the components’ exergy destruction rate and cost rates. Regarding the conventional exergy analysis for the whole system, the compressor represents the largest exergy destruction source of 26%. On the other hand, the generator shows the lowest sources (2%). The advanced exergy analysis indicates that 59.4% of the whole system thermodynamical inefficiencies can be avoided by further design optimisation. The compressor has the highest contribution to the destruction in the avoidable exergy destruction rate (21%), followed by the ejector (18%) and condenser (8%). Moreover, the advanced exergoeconomic results prove that 51% of the system costs are unavoidable. In system components cost comparison, the highest cost comes from the condenser, 30%. In the same context, the ejector has the lowest exergoeconomic factor, and it should be getting more attention to reduce the irreversibility by design improving. On the contrary, the evaporator has the highest exergoeconomic factor (94%).

Advanced exergoeconomic analysis with using modified productive structure analysis: An application for a real gas turbine cycle

In this study, advanced exergoeconomic analysis is performed for a gas turbine cycle located in Inchon/South Korea. In addition, an approach combining advanced exergy analysis with modified productive structure analysis is applied to the system and the results are compared. Both methods showed that higher part of exergy destruction cost rate for overall system was unavoidable. The investment cost rate of system equipment was also unavoidable. Avoidable exergy destruction cost rate was higher than unavoidable part only for gas turbine. The exergy destruction cost rates obtained with approach are considerably lower than the results obtained with the advanced exergoeconomic analysis. This situation affected the strategies developed to obtain a cost-effective system for gas turbine. Advanced exergoeconomic analysis proposed reducing the exergy destruction cost rate for gas turbine. However, for gas turbine, the approach proposed reducing the investment cost rate. The sum of exergy destruction cost rate of system equipment was higher than that of overall system in advanced exergoeconomic analysis. However, the exergy destruction cost rate of overall system was equal to the sum of exergy destruction cost rate of system equipment in the approach. Finally, it can be concluded that the results obtained with the approach were more compatible.

Conventional and Advanced Exergy and Exergoeconomic Analysis of a Spray Drying System: A Case Study of an Instant Coffee Factory in Ecuador

Instant coffee is produced worldwide by spray drying coffee extract on an industrial scale. This production process is energy intensive, 70% of the operational costs are due to energy requirements. This study aims to identify the potential for energy and cost improvements by performing a conventional and advanced exergy and exergoeconomic analysis to an industrial-scale spray drying process for the production of instant coffee, using actual operational data. The study analyzed the steam generation unit, the air and coffee extract preheater, the drying section, and the final post treatment process. The performance parameters such as exergetic efficiency, exergoeconomic factor, and avoidable investment cost rate for each individual component were determined. The overall energy and exergy efficiencies of the spray drying system are 67.6% and 30.6%, respectively. The highest rate of exergy destruction is located in the boiler, which amounts to 543 kW. However, the advanced exergoeconomic analysis shows that the highest exergy destruction cost rates are located in the spray dryer and the air heat exchanger (106.9 $/h and 60.5 $/h, respectively), of which 47.7% and 3.8%, respectively, are avoidable. Accordingly, any process improvement should focus on the exergoeconomic optimization of the spray dryer.

Modified auxiliary exergy costing in advanced exergoeconomic analysis applied to a hybrid solar-biomass organic Rankine cycle plant

This study concerns advanced exergoeconomic analysis of a hybrid solar-biomass organic Rankine cycle (ORC) cogeneration plant. The hybrid plant had been previously conceived as structural optimization scheme to upgrade thermo-economic performance of a real 630 kW solar-ORC plant which currently runs in Ottana, Italy. The irreversibility rates, investment cost rates and irreversibility cost rates were obtained for each system component, based on thermodynamic balance as well as cost balance and auxiliary equations established for the components. Next, the avoidable/unavoidable and exogenous/endogenous splitting options were applied to investigate the sources of thermo-economic losses in the system, the effects of component interactions on the losses, as well as the best approach to improving the system. The main contribution of this paper centers on modification of the traditional auxiliary exergy costing in advanced exergoeconomic methodology, by incorporating stream energy quality into the cost formation process. Results showed that more than 50% of total irreversibility rates can be avoided in almost all of the components of the hybrid plant, most of which are endogenous. Similarly, it was obtained that component interdependencies have little impact on thermo-economic losses. Specifically, more than 60% of irreversibility cost rates could be avoidable in the hybrid plant by optimizing internal operations of each of the system components individually. Moreover, results showed that how auxiliary exergy costing is defined in advanced exergoeconomic method plays a significant role on the analysis, and the modified approach presented in this study is a viable choice.

Conventional and advanced exergoeconomic assessments of a CCHP and MED system based on solid oxide fuel cell and micro gas turbine

This paper presents an assessment of a combined cooling, heating and power (CCHP) and multi-effect desalination (MED) system based on SOFC/MGT by conventional and advanced exergoeconomic analyses. The conventional exergy analysis can reveal the sources of irreversibility in the system. The largest exergy destruction occurs in after burner followed by SOFC and MED, accounting for 20.079%, 12.986%, 12.907%, respectively. In the advanced analysis, the exergy destruction, exergy destruction cost and investment cost are split into avoidable/unavoidable and endogenous/exogenous parts to investigate the real potentials of exergy and economic performances. The advanced analysis results indicate that the major exergy destructions of most components are endogenous parts with inverter, MGT and air compressor owning the most potentials to reduce exergy destructions. The modified exergy efficiency of each component in the advanced analysis is higher than the conventional one. Finally, three possible strategies are suggested to reduce the avoidable exergy destruction cost rates.

Advanced exergoeconomic evaluation on supercritical carbon dioxide recompression Brayton cycle

This study proposes a comprehensive understanding of the supercritical carbon dioxide recompression Brayton cycle by means of extending and applying the advanced exergoeconomic method as one of the first attempts. The advantages of this advanced exergy-based method are determining the real potential for improvement of each significant component and considering the interactions among system components, which cannot be achieved by using the conventional method. The unavoidable/avoidable and endogenous/exogenous concepts are introduced, and detailed modeling is performed to calculate exergy destruction and investment costs. The results demonstrate that the unavoidable value of each component is higher than the avoidable value for exergy destruction cost (except for high temperature recuperator). Even under the most optimistic scenario, the total exergy destruction cost can only be reduced by 2199.29 $/h (38.86%), and about half of this avoidable variable is exogenous. According to the results of traditional exergoeconomic analysis, the reactor is recommended as the governing component to improve the cost effectiveness of the cycle due mainly to its highest operating cost (5313.39 $/h). On the contrast, the turbine should have the highest improvement priority owing to the highest value of the avoidable operating cost (1390.88 $/h). The findings provide a novel way to guide the design and evaluation of the carbon dioxide Brayton cycle through benefiting from the advanced exergoeconomic analysis.

Advance Exergo-Economic Analysis of a Waste Heat Recovery System Using ORC for a Bottoming Natural Gas Engine

This manuscript presents an advanced exergo-economic analysis of a waste heat recovery system based on the organic Rankine cycle from the exhaust gases of an internal combustion engine. Different operating conditions were established in order to find the exergy destroyed values in the components and the desegregation of them, as well as the rate of fuel exergy, product exergy, and loss exergy. The component with the highest exergy destroyed values was heat exchanger 1, which is a shell and tube equipment with the highest mean temperature difference in the thermal cycle. However, the values of the fuel cost rate (47.85 USD/GJ) and the product cost rate (197.65 USD/GJ) revealed the organic fluid pump (pump 2) as the device with the main thermo-economic opportunity of improvement, with an exergo-economic factor greater than 91%. In addition, the component with the highest investment costs was the heat exchanger 1 with a value of 2.769 USD/h, which means advanced exergo-economic analysis is a powerful method to identify the correct allocation of the irreversibility and highest cost, and the real potential for improvement is not linked to the interaction between components but to the same component being studied.

Advanced exergoeconomic analysis of solar-biomass hybrid systems for multi-energy generation

In this study, advanced exergoeconomic analysis of solar-biomass hybrid energy systems for the northern part of Cameroon is conducted. Three concentrating solar power (CSP) technologies, parabolic trough collector (PTC), linear Fresnel reflector (LFR) and solar tower (ST), hybridised with biomass-fired (BF) technology are investigated. It is found that exergy destruction from the solar field alone is responsible for the most of the whole exergy destructions (86.3% for PTC-BF, 92.2% for ST-BF and 85.4% for LFR-BF). The results show that LFR-BF hybrid system is the best cost-efficient system while ST-BF hybrid system is the worst cost-efficient system considering initial investment, avoidable-endogenous exergy destruction, cost associated with avoidable-endogenous exergy destruction and total cost required for the optimisation.

Advanced exergoeconomic analysis of solar-biomass hybrid systems for multi-energy generation

Advanced exergoeconomic analysis of solar-biomass hybrid systems for multi-energy generation

Advanced exergy and exergoeconomic analysis for a polygeneration plant operating in geothermal cascade

This paper presents an advanced exergy and exergoeconomic analysis applied to a polygeneration plant operating in a geothermal cascade arrangement. An organic Rankine cycle (ORC), an absorption chiller and a dehydrator are the main components of the plant. The energy and exergy analysis of the polygeneration plant were carried out operating under real, unavoidable and ideal conditions. Considering real conditions, the polygeneration plant is able to reach a power output of 40 kWe, a cooling effect of 175.8 kWf and 30 kWt of useful heat for dehydration. The conventional exergy analysis shows that the component with the highest destruction of exergy of the polygeneration plant is the main heat exchanger (HX-I) having 44.05 kW, followed by the ORC with 38.58 kW. The advanced exergy analysis also indicates that 10.61 kW and 2.28 kW of exergy destruction in the HX-I and in the ORC can be avoided by improving design variables of these components. In this same context, the thermally activated refrigeration (TAR) can avoid destroying endogenously 7.36 kW while interacting with the other components of the plant operating under ideal conditions. On the other hand, the conventional exergoeconomic analysis reveals a cost of electricity production of 8.54 $/h, a cost of cooling production of 7.78 $/h and a cost of useful heat production for dehydration of 3.52 $/h. Finally, the advanced exergoeconomic analysis indicates that the heat exchanger HX-II is the component of the plant where more opportunity for reducing exergy destruction can be found.