Exergoeconomic Performance Parameters Research Articles

Exergoeconomic Analysis of a Mechanical Compression Refrigeration Unit Run by an ORC.

To improve the efficiency of a diesel internal combustion engine (ICE), the waste heat carried out by the combustion gases can be recovered with an organic Rankine cycle (ORC) that further drives a vapor compression refrigeration cycle (VCRC). This work offers an exergoeconomic optimization methodology of the VCRC-ORC group. The exergetic analysis highlights the changes that can be made to the system structure to reduce the exergy destruction associated with internal irreversibilities. Thus, the preheating of the ORC fluid with the help of an internal heat exchanger leads to a decrease in the share of exergy destruction in the ORC boiler by 4.19% and, finally, to an increase in the global exergetic yield by 2.03% and, implicitly, in the COP of the ORC-VCRC installation. Exergoeconomic correlations are built for each individual piece of equipment. The mathematical model for calculating the monetary costs for each flow of substance and energy in the system is presented. Following the evolution of the exergoeconomic performance parameters, the optimization strategy is developed to reduce the exergy consumption in the system by choosing larger or higher-performance equipment. When reducing the temperature differences in the system heat exchangers (ORC boiler, condenser, and VCRC evaporator), the unitary cost of the refrigeration drops by 44%. The increase in the isentropic efficiency of the ORC expander and VCRC compressor further reduces the unitary cost of refrigeration by another 15%. Following the optimization procedure, the cost of the cooling unit drops by half. The cost of diesel fuel has a major influence on the unit cost of cooling. A doubling of the cost of diesel fuel leads to an 80% increase in the cost of the cold unit. The original merit of the work is to present a detailed and comprehensive model of optimization based on exergoeconomic principles that can serve as an example for any thermal system optimization.

Experiment on waste heat recovery‐assisted heat pump drying of food chips: Performance, economic, and exergoeconomic analyses

Novel waste heat recovery-assisted heat pump dryer is designed, developed, and experimented in different operating modes. Energy, exergy, economic, and exergoeconomic parameters of the dryer with and without waste heat recovery are experimentally compared. Radish chips are dried to remove moisture from 93.5% to 10.5% at fixed dryer inlet air velocity. Both energy and exergy efficiencies are found highest for the waste heat recovery-assisted (hybrid) system (56.26% and 35.9%, respectively). Specific moisture extraction rate (2.4 kg/kWh) and coefficient of performance (6.72) are highest for the hybrid system. The payback period for the hybrid system over the simple system is 33 months. The lowest exergoeconomic factor is for expansion devices in both simple and hybrid systems (0.0918 and 0.1348, respectively). Total exergy destruction costs for simple and hybrid systems are 0.10148 and 0.1266 $/h, respectively. The most important component that needs to improve based on the exergoeconomic factor is the drying chamber. Practical applications In the present study, a novel heat pump dryer assisted with waste heat recovery from the diesel engine is designed and developed. Various energy, exergy, economic, and exergoeconomic performance parameters with and without waste heat recovery are experimentally compared. To check the applicability, the radish chips have been dried to remove moisture from 93.5% to 10.5% at fixed dryer inlet air velocity. The testing shows that the proposed system is superior as compared to the simple heat pump dryer in terms of both energy and exergy efficiencies, specific moisture extraction rate, and overall heating coefficient of performance. The payback period for the proposed system over a simple one is found 3 years approximately. The proposed system can be a futuristic and promising solution for the drying applications, which satisfies two purposes: An effective way to utilize the engine waste heat and superior system performance.

A comparative analysis of novel combined flash-binary cycles for Sabalan geothermal wells: Thermodynamic and exergoeconomic viewpoints

Sabalan geothermal field is one of the most important geothermal fields in Iran. In this study, four novel configurations namely Single Flash-ORC (SF-ORC), Double Flash 1-ORC (DF1-ORC), Double Flash 2-ORC (DF2-ORC) and Triple Flash-ORC (TF-ORC) are proposed to produce power from two wells of the field. The configurations are assessed by thermodynamic and exergoeconomic viewpoints. The exergy and SPECO based exergoeconomic equations are developed for the components of the proposed cycles and thermodynamic as well as exergoeconomic performance parameters are calculated for the components and the cycles. A comprehensive parametric study is also carried out for the proposed configurations considering various working fluids in the ORCs. Moreover, an optimization is performed to maximize the produced power from the wells. The results depicted that the DF1-ORC produces 4.03%, 1.32% and 1.2% more power than the SF-ORC, DF2-ORC and TF-ORC, respectively, in the optimum condition. It can be concluded from the exergoeconomic analysis that the SF-ORC with R123 working fluid has the best exergoeconomic performance with the power specific cost of 3.62 $/GJ. The thermodynamic and exergoeconomic performance of the DF1-ORC is compared with previous similar studies which shows the superiority of the proposed cycle.

Experimental energy, exergy, economic and exergoeconomic analyses of batch-type solar-assisted heat pump dryer

In the present study, a batch-type solar-assisted heat pump dryer (SAHPD) has been developed and experimented in both simple heat pump dryer (HPD) and SAHPD modes for closed system drying of banana chips. The effect of drying time on various energy, exergy, economic and exergoeconomic performance parameters has been investigated. The banana chips have been dried to remove moisture from 83.5% to 11.5% at an air velocity of 1 m/s in the drying chamber. Both energy efficiency and exergy efficiency are found higher for SAHPD. The specific moisture extraction rate is higher for SAHPD as compared to simple HPD. On the basis of economic analysis, the payback period for the SAHPD over the simple HPD is found 46 months. The lowest exergoeconomic factor is for the expansion device in simple HPD and SAHPD with determined values as 0.1395 and 0.2053, respectively. Total exergy destruction cost for simple HPD and SAHPD is 0.1185 $/h and 0.1386 $/h, respectively. It is observed that the most important components that needed to improve based on exergoeconomic factor are expansion device and evaporator. The present study reveals that the SAHPD system is much better than the simple HPD system.

Exergoeconomic Analysis of an Industrial Cogeneration Cooling System Powered By Natural Gas Fueled Diesel Engine

This study presents the exergy and exergoeconomic analysis of a natural gas-powered diesel cogeneration system. The cogeneration system is designed for a sports complex with 1000 m2 closed area in Afyonkarahisar city. Natural gas is used as the fuel in the cogeneration system of the sports complex, which includes a swimming pool and ice rink. The natural gas diesel engine is used as the primary energy source for the cogeneration system. In the system, the electricity required for the cooling cycle is produced from the natural gas diesel engine. At the same time, the engine exhaust gases are used in the process of heat generation for swimming pool water heating. Finally, the waste heat discharged from the system is used to produce electricity in the thermoelectric power unit. The cogeneration system was modeled thermodynamically by the EES program on a computer and then economically analyzed by using the Aspen Plus program. The operation of the cogeneration system is described in detail, and a methodology based on exergoeconomic relations and SPECO method is provided to allocate cost flows through subcomponents of the system. The results were compared by using thermodynamic and exergoeconomic performance parameters. The exergetic efficiency of the cogeneration system is found to be 28.74%, which indicates that 71.26% of the total exergy input to the system, mainly by natural gas, is destroyed. As a result of the economic analysis of the cogeneration system, the investment cost was calculated as 62,000 $. The exergetic cost rate and the specific unit exergetic cost of the power produced in the cogeneration system are calculated to be 0.75 $/h and 10.93 $/GJ (0.039 $/kWh), respectively. The specific unit exergetic cost of the energy produced in the cogeneration system for cooling the ice rink and heating the swimming pool in the sports complex are calculated to be 6.152 $/GJ (0.022 $/kWh) and 4.221 $/GJ (0.0152 $ /kWh), respectively.

Exergo-economic cost accounting for PW4000 turbofan engine and its components

You The several series of PW4000 high bypass turbofan engine have used so far in many aircrafts. These commercial engines have played a crucial role on passenger and freight transportations. Namely, these engines are closely related to the environment impacts and security of energy supply. In this article, exergoeconomic analysis which is useful tool to investigate existing potential for improvement of the a system efficiency were carried out. The assesment, design and optimization of energy consuming systems are performed by means of these analyses. Therefore, thermo-economic costs were assigned to existing exergetic values of PW400 engine. Also exergo-economic performance parameters were evaluated. Finally, exergoeconomic deputy parameters were examined to understand relations with exergo-economic parameters. Based on the results of exergo-economics analysis, for Fan and exhaust, specific thrust costs are estimated 5.7051 $/hkN and 68.45$/hkN respectively. Also exergo-economics factor of PW4000 is found 7.958 % , while relative cost difference is determined at highest rate with 24.458 % for combustion chamber . With examination relations between economic variables and exergo-economic performance parameters, the change between 0.6 and 1.2 $/kg in the fuel price leads to increase the exhaust and fan specific thrust costs with 82.4701 $/hkN and 5.4332 $/hkN respectively. It is expected that conclusions of this study are helpful to notify exergo-economic impact of PW4000 engine Also, it may be benchmarking for similar gas turbine engines.

Comprehensive exergoeconomic analysis of a municipal solid waste digestion plant equipped with a biogas genset

A comprehensive exergoeconomic performance analysis of a municipal solid waste digestion plant integrated with a biogas genset was conducted throughout this study in order to highlight its bottlenecks for further improvements. Exergoeconomic performance parameters of each component of the plant were determined by solving exergy and cost balance equations based on Specific Exergy Costing (SPECO) approach. The analysis was conducted to reveal the cost structure of the plant based on actual operating information and economic data. The exergy unitary cost of two main products of the plant, i.e., bioelectricity and biofertilizer were determined at 26.27 and 2.27 USD/GJ, respectively. The genset showed the highest overall cost rate (101.27 USD/h) followed by digester (68.41 USD/h). Furthermore, the net bioelectricity amounted to 67.81% of the overall cost rate of the products, while this value was 32.19% for both liquid and dewatered digestates. According to the results obtained, efforts should mainly focus on enhancing the efficiency of the genset in order to boost the overall performance of the system exergoeconomically. In addition, minimizing the investment-related cost of the digester could also substantially enhance the exergoeconomic performance of the plant.

Exergoeconomic evaluation of a ground-source heat pump food dryer at varying dead state temperatures

This study deals with exergoeconomic analysis of a ground-source heat pump food dryer through the specific exergy costing method for the first time. Moreover, variations of the exergetic and exergoeconomic performance parameters with dead state temperatures are also investigated and discussed with the literature results. The results show that the condenser is the most important system component from the efficiency improvement point of view with a total cost rate of 1.347 $/h and exergoeconomic factor of 0.029. The main part of the exergy costs accumulated in the condenser is generated during the process and the optimization of the operating conditions of the condenser has a major importance in improving the overall system performance. Furthermore, heat exchangers in the ground-source heat pump system are influenced from the alteration of the dead state temperature. Increase in the dead state temperature generally leads to decrease in the exergetic efficiencies of system components. The total costs occurred in the evaporator significantly increase with the rise in the dead state temperature. Authors expect that the results of the present study can provide some guidelines for the designs of the ground-source heat pump systems.

Thermodynamic and exergoeconomic analysis of a cement plant: Part II – Application

This paper is Part 2 of the study on the thermodynamic and exergoeconomic analysis of a cement plant. In Part 1, thermodynamic and exergoeconomic formulations and procedure for such a comprehensive analysis are provided while this paper provides an application of the developed formulation that considers an actual cement plant located in Gaziantep, Turkey. The overall energy and exergy efficiencies of the plant is found to be 59.37% and 38.99% respectively. The exergy destructions, exergetic cost allocations, and various exergoeconomic performance parameters are determined by using the exergoeconomic analysis based on specific exergy costing method (SPECO) for the entire plant and its components. The specific unit exergetic cost of the farine, clinker and cement produced by the cement plant are calculated to be 43.77USD/GJ, 133.72USD/GJ and 180.5USD/GJ respectively. The specific manufacturing costs of farine, clinker and cement are found to be 3.8USD/ton, 33.11USD/ton and 41.84USD/ton respectively.

Influence of reference temperature on exergy and exergoeconomic performance of a natural gas fired thermal power plant

The influence of reference temperature on exergy and exergoeconomic performance parameters of a thermal plant was investigated. The plant was simulated using HYSYS (2003) process simulator software and the exergy and exergoeconomic analyses were done using Microsoft EXCEL spreadsheet. As reference temperature increased from 15°C to 35°C, exergy efficiency decreased from 11.7% to 11.5% and irreversibility increased from 1790 MW to 1812 MW. Also, overall exergy cost decreased from 6650.78 MW to 6055.40 MW and monetary cost from $75,343.84/h to $68,430.19/h. The optimum (base case) reference temperature, where the exergy and the monetary exergy loss costs were at minimum, was found to be 30°C. At this temperature both the condenser and boiler units made significant contributions to the process exergy and monetary exergy loss costs. The study concluded that the performance of the thermal plant depends on reference temperature, efficiencies of condenser and boiler units.

Energetic, Exergetic, and Exergoeconomic Analyses of Spray-Drying Process during White Cheese Powder Production

In this study, white cheese powder was produced using a pilot-scale spray dryer. Drying experiments were carried out with an inlet drying air temperature range of 160–230°C, an outlet drying air temperature range of 60–100°C, and an atomization pressure range of 294.2–588.4 kPa. The performance of the spray-drying process and the effects of process conditions on the process performance were evaluated using energetic, exergetic, and exergoeconomic analyses. The performance assessment was performed by using energy and exergy efficiencies, improvement potential ( ) rate, total cost, and exergoeconomic factor terms. A comprehensive parametric study was conducted to investigate the effect of varying dead-state temperatures on exergetic and exergoeconomic performance parameters for the drying process. Correlations between the performance parameters and dead-state temperatures were developed. Exergetic efficiency values and rates were found to vary between 2.66 and 6.00% and 7.54 and 10.96 kW, respectively, and ...

Exergoeconomic (Thermoeconomic) Analysis and Performance Assessment of a Gas Engine–Driven Heat Pump Drying System Based on Experimental Data

Exergoeconomic analysis has been used as a powerful tool to study and optimize various types of energy-related systems. In this study, we use the specific exergy cost (SPECO) method to calculate exergy-related parameters and display cost flows for all streams and components in a gas engine–driven heat pump drying system based on the experimental data. We analyze and evaluate the performance of the drying system components and the drying process for three different medicinal and aromatic plants from an exergoeconomic point of view. We also investigate the effect of varying dead (reference) state temperatures on exergoeconomic performance parameters for the drying system components and drying process. Although the condenser and drying chamber of the gas engine–driven heat pump dryer were significantly affected by the ambient temperature, the gas engine was slightly influenced by the ambient temperature. At low ambient temperatures, the exergy rates increased and the most effective performance obtained from this dryer was at 0°C. The performance of the drying process also increased at low ambient temperatures. This study demonstrated that exergoeconomic analysis can provide more information than exergy analysis, and the results obtained from the exergoeconomic analysis provided cost-based information, suggesting potential locations for drying system improvement.

Exergoeconomic analyses of a gas engine driven heat pump drier and food drying process

Exergoeconomic analysis of a pilot scale gas engine driven heat pump (GEHP) drying system is performed based on the experimental values using Exergy, Cost, Energy and Mass (EXCEM) analysis method in this study. The performance of the drying system components is discussed, while the important system components are determined to improve the system efficiency. The performance of the drying process is also analyzed for three different medicinal and aromatic plants from the exergoeconomic point of view. A comprehensive parametric study is conducted to investigate the effect of varying dead (reference) state temperatures on exergoeconomic performance parameters for both drying system components and drying process. The correlations between the performance parameters and dead state temperatures are developed. The results have indicated that the dead state temperature affects the performance parameters, particularly the drying process parameters. Rising the dead state temperature leads to an increase in the exergy efficiencies of the drying process and a decrease in the ratio of the thermodynamic loss rate to the capital cost (R˙ex) values in a polynomial form. R˙ex values of the drying process are obtained to be very higher compared to those of the drying system components.

Thermodynamic and thermoeconomic analyses of a trigeneration (TRIGEN) system with a gas–diesel engine: Part II – An application

The paper is Part 2 of the study on the thermodynamic and thermoeconomic analyses of trigeneration system with a gas–diesel engine. In Part 1, thermodynamic and thermoeconomic methodologies for such a comprehensive analysis were provided, while this paper applies the developed methodology to an actual TRIGEN system with a rated output of 6.5 MW gas–diesel engine installed in the Eskisehir Industry Estate Zone, Turkey. Energy and exergy efficiencies, equivalent electrical efficiency, the Public Utility Regulatory Policies Act (PURPA) efficiency, fuel energy saving ratio, fuel exergy saving ratio and other thermodynamic performance parameters are determined for the TRIGEN system. The efficiencies of energy, exergy, PURPA and equivalent electrical efficiency of the entire system are found to be 58.97%, 36.13%, 45.7% and 48.53%, respectively. For the whole system and its components, exergetic cost allocations and various exergoeconomic performance parameters are calculated using the exergoeconomic analysis based on specific exergy costing method (SPECO). The specific unit exergetic cost of the net electrical power, heat energy in the Factory Heating Center (FHC) heating, heat energy in the Painting Factory Heating (PFH) and chilled water in the absorption chiller (ACh) produced by the TRIGEN system are obtained to be 45.94 US$/GJ, 29.98 US$/GJ, 42.42 US$/GJ and 167.52 US$/GJ, respectively.

An exergy–cost–energy–mass analysis of a hybrid copper–chlorine thermochemical cycle for hydrogen production

An exergoeconomic assessment using exergy–cost–energy–mass (EXCEM) analysis is reported of a copper–chlorine (Cu–Cl) thermochemical water splitting cycle for hydrogen production. The quantitative relation is identified between capital costs and thermodynamic losses for devices in the cycle. A correlation detected in previous assessments, suggesting that devices in energy systems are configured so as to achieve an overall optimal design by appropriately balancing thermodynamic (exergy-based) and economic characteristics of the overall system and its components, is observed to apply for the Cu–Cl cycle. Exergetic cost allocations and various exergoeconomic performance parameters are determined for the overall cycle and its components. The results are expected to assist ongoing efforts to increase the economic viability and to reduce product costs of potential commercial versions of this process. The impacts of these results are anticipated to be significant since thermochemical water splitting with a copper–chlorine cycle is a promising process that could be linked with nuclear reactors to produce hydrogen with no greenhouse gases emissions, and thereby help mitigate numerous energy and environment concerns.

Exergetic and thermoeconomic analyses of diesel engine powered cogeneration: Part 2 – Application

This paper is Part 2 of the study on the exergetic and thermoeconomic analysis of diesel engine powered cogeneration (DEPC) systems. In Part 1, formulations and procedure for such a comprehensive analysis are provided while this paper provides an application of the developed formulation that considers an actual DEPC plant installed in Gaziantep, Turkey. The plant has a total installed electricity and steam generation capacities of 25.3 MW and 8.1 tons/h at 170 °C, respectively. Exergy destructions, exergy efficiencies, exergetic cost allocations, and various exergoeconomic performance parameters are determined for the entire plant and its components. The exergy efficiency of the plant is determined to be 40.6%. The exergoeconomic analysis is based on specific cost method (SPECO) and it is determined that the specific unit exergetic cost of the power produced by the plant is 10.3 $/GJ.