Exergoeconomic Assessment Research Articles

Optimizing building energy efficiency with a combined cooling, heating, and power (CCHP) system driven by boiler waste heat recovery

In light of increasing challenges related to fossil fuel consumption, global warming, and rising energy costs, optimizing energy systems has become essential. This study introduces a multi-purpose system designed to capture and utilize waste heat from boiler flue gases at the Tous power plant for simultaneous power generation, cooling, and heating. The system integrates an Organic Rankine Cycle (ORC) for power generation and an Absorption Refrigeration Cycle (ARC) for cooling, with the added function of recovering waste heat to preheat natural gas for the boiler and power plant. The system's performance was rigorously analyzed through energy, exergy, and exergoeconomic assessments. To determine the optimal operating conditions, a multi-objective optimization was conducted using the TOPSIS technique, focusing on critical parameters such as flue gas exit temperature, natural gas inlet temperature, and turbine inlet pressures. The results identified optimal conditions with a flue gas exit temperature of 532.5 K, a natural gas inlet temperature of 285 K, and turbine inlet pressures of 2.54 MPa and 14.62 MPa for the first and second turbines, respectively. Under these conditions, the system achieved an exergy efficiency of 41.1 %, cooling capacity of 133.1 kW, power generation of 210.4 kW, heat transfer to natural gas of 979.6 kW, and operational costs of 8.53 $/h. This study highlights the potential of the proposed system to significantly enhance energy efficiency and reduce operational costs in practical applications, offering a sustainable solution for energy management.

The optimization of a low-temperature geothermal-driven combined cooling and power system: Thermoeconomic and advanced exergy assessments

Switching from fossil fuels to geothermal energy can provide a solution to environmental issues and the energy crisis caused by power and cooling generation systems. In this regard, this study examines an innovative cogeneration system that utilizes low-temperature geothermal energy to generate power and cool the built environment simultaneously. The proposed system incorporates a Kalina-34 cycle, complemented by an integrated absorption refrigeration cycle. System analysis encompasses thermodynamic and exergoeconomic assessments, as well as parametric investigations to gauge the effects of critical parameters on system performance. Following a parametric study, the TOPSIS multicriteria decision-making technique is applied to optimize turbine inlet pressure, vapor generator temperature difference, and ammonia concentration. Finally, the main source of irreversibility is compared by conventional and advanced exergy analyses under optimal conditions. Results show that under optimal conditions, the energy utilization factor (EUF), exergy efficiency, and unit co-generation cost (UCGC) are 11.15 % (30.5 % improvement), 45.54 % (20.1 % improvement), and 6.04 $/GJ (1.63 % reduction), respectively. Furthermore, while conventional exergy analysis prioritizes the improvement of the condenser-1, vapor generator, and turbine in that order, advanced exergy analysis suggests a different priority order, with condenser-1, turbine, and vapor generator being the main objects of improvement, respectively. Implementing this study will significantly improve and optimize the proposed system.

Optimizing small-scale power generation: Exergetic and exergoeconomic evaluation of an integrated gasification system for sacha inchi residues

Biomass is the primary non-fossil energy source, especially in regions such as Central and South America, and holds immense potential for non-fossil energy. Utilizing waste biomass, mainly through gasification for syngas production, offers environmental advantages over direct combustion for electricity and heating. The sacha inchi seed shell (SIS), currently discarded, presents an untapped biomass resource. Hence, the significance of this work lies in assessing the gasification potential of SIS for decentralized power generation, targeting rural off-grid areas. Detailed modeling of mass, energy, and exergy flows was used to establish a self-sustaining 35 kW sacha inchi processing plant using Aspen Plus software. The best operational condition was identified at an equivalence ratio of 0.25, achieving 100 % carbon conversion efficiency and 73.5 % cold gas efficiency with a lower heating value of 6.126 MJ/kg. Exergetic analysis highlights heat exchangers and the power generator as the least efficient components (0.214 % to 27.85 %), contrasting with superior efficiencies in the gasifier, compressor, and cyclone (82.85 %, 85.5 %, and 96.13 %, respectively). Exergoeconomic assessment reveals an energy cost of 10.25 USD/GJ, notably lower than Colombian energy costs for equivalent power needs.

Exergoeconomic assessment of a multi-section solar distiller coupled with solar air heater: Optimization and economic viability

This study focuses on optimizing the solar distiller and provides a foundation for future research and development in solar distillation technologies. This paper does an exergoeconomic analysis of a multi-section solar distiller (MS-SS) system that is combined with a solar air heater (SAH). Therefore, its objective is to determine the most effective operational and design parameters while taking into account the system's lifespan and interest rate. This will offer significant knowledge for improving the MS-SS. Key parameters examined in the study include exergoeconomic indicators, exergy production factor (EPF), exergy-based loss rate, exergy efficiency, and water cost. Variations in exergy loss rate across different seasons were observed, with implications for system efficiency. The exergoeconomic analysis demonstrates the impact of interest rates on the system's economic viability, with corresponding effects on water costs. The key findings suggest varying daily output and exergy efficiency, with the lowest values recorded in winter and the highest in summer. Summer demonstrates superior output exergy, averaging of 145 × 103 Wh per month. In the normal case of output salinity between 0 and 500 ppm, the cost was reduced by 96.7 %, and by 96.3 % in the case of four interior sections. Water cost reduction is also observable at the same output salinity, with 54.1 % at 0 ppm and 62.4 % at 200 ppm between number of interior sections = 0 and 4.

Exergoeconomic evaluation and optimization of a solar-powered polygeneration system producing freshwater, electricity, hydrogen, and cooling

This study presents a comprehensive exergoeconomic assessment and optimization of a pioneering solar-powered polygeneration system designed for simultaneous production of electricity, cooling, freshwater, and hydrogen, aiming to fill the gap in knowledge about such a polygeneration system. The study employs an advanced methodology to evaluate future improvement methods, considering the system's performance and economic viability. The Specific Exergy Costing (SPECO) method is used for exergoeconomic analysis, and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) is preferred to reveal Multiple Criteria Decision Analysis (MCDA) for optimization.As an important conclusion, it is recognized that system modifications should reduce the financing cost while simultaneously increasing the system's lifespan and annual operational time. The most expensive components of the system are the PTC, ORC, and electrolyzer, which are responsible for 51%, 23%, and 18% of the total cost of energy destruction, respectively. Thus, purchase price reduction and improvement in the efficiencies of these units are crucial. Also, considering the exergoeconomic factor (fc) values calculated for the system components, it is necessary to increase the efficiency of the compressor and electrolyzer, which have fc values of 37.37% and 32.1%, respectively, even if it results in higher capital expenditures. Additionally, it should be preferred to reduce the capital costs of the other system components, which have higher fc values in the range of 46.68% and 52.47%, without reducing their efficiencies significantly.

Exergetic and exergoeconomic assessments of a diesel engine fuelled with waste chicken fat biodiesel-diesel blends

Researchers have constantly been looking for renewable alternative fuels due to high fuel price volatility, energy security concerns, and produced harmful emissions. One of the promising alternatives is to produce biodiesel from waste economical feedstock such as chicken fat. Esterification and transesterification are used to create methyl ester from chicken fat. Then, 25%, 50%, 75%, and 100% of chicken oil biodiesel are volumetrically blended with diesel fuel. Diesel engine is loaded between 0% and 100% at 3000 rpm rated speed. Exergetic and exergoeconomic assessments of diesel engine fuelling with blends of chicken biodiesel were conducted in the present study. Diesel oil performed most efficiently in terms of exergy. For B100, the worst exergetic results are attained. The exergy efficiency of test engine at 75% engine load was 33.25% for the D100 and 27.85% for the B100. D100 produced the best exergoeconomic findings, while adding biodiesel to D100 made the exergoeconomic parameters worse. Crankshaft work had a particular exergy cost of 110.02 $/GJ for D100 and 194.37 $/GJ for B100 at 75% of engine output power. In the conclusion, it is noted that the waste chicken fat methyl ester can be used at low fractions as a substitute for traditional diesel fuel without modifying the engine, and this is a promising solution for waste management, turning waste products into an energy source, and dwindling fossil fuel reserves.

A parametric study on energy, exergy and exergoeconomic assessments of a modified auto-cascade refrigeration cycle supported by a dual evaporator refrigerator

This paper presents an evaluation of the energetic, exergetic, and exergoeconomic performances of a modified auto-cascade refrigeration (MACR) cycle integrated with a dual evaporator refrigerator (DER) to determine optimum operating conditions. DER facilitates a reduction in the compression ratio, allowing the low-boiling-point component to release more heat before entering the evaporator. In this study, the R170/R290 refrigerant mixture, which has a low global warming potential but an explosion risk, was used. The main purpose of this study is to eliminate the risk of explosion by reducing the compressor discharge temperature and at the same time to enhance the overall cycle performance. To achieve this, DER is used instead of air-cooled coils, which have limited cooling performance. Despite an ambient temperature of 35°C, the MACR cycle achieved a remarkable 51.29 % reduction in compressor discharge temperature when the separator inlet temperature was reduced to 10°C by the DER. It also results in a 72.73% reduction in compression work rate and a significant 137.02% increase in cooling effect compared to the conventional auto-cascade refrigeration cycle. Furthermore, the MACR cycle exhibits notable improvements in total exergy destruction rate and exergy destruction cost rate with a 75.23% and a 76.07% reduction, respectively. Simultaneously, the exergy efficiency and the exergoeconomic factor increased by 266.67% and 179.15%, respectively. The MACR cycle achieves optimum energy and exergy performance with a 60% R170 mass fraction and 0.50 vapor quality, resulting in 1.429kW compression work rate, a COP of 0.70, and an exergy efficiency of 26.66 %. The optimum exergoeconomic performance is achieved with a 40% R170 mass fraction and 0.50 vapor quality.

Thermodynamic and exergo-economic analyses and multi-objective optimization of an innovative and efficient geothermal-assisted power and hydrogen cogeneration system

This paper presents an efficient integration of a flash-binary geothermal system with a double-pressure Kalina cycle and a proton exchange membrane electrolyzer unit. The main objective is to generate power and hydrogen simultaneously. A comprehensive thermodynamic analysis is conducted, encompassing mass, energy, and exergy assessments, along with an exergo-economic approach, to thoroughly evaluate system performance. The operation of the system is examined under varying conditions, and trends in the assessment indexes are predicted accordingly. The designed system achieves notable results, producing 1018 kW of net power and 0.1119 kg/h of hydrogen. The thermal and exergetic efficiencies are found to be 14.34 % and 45.59 %, respectively, based on the thermodynamic approach. From an economic perspective, the payback period is estimated to be 2.51 years, while the sum unit cost of products is calculated at 8.94 $/GJ. Furthermore, a detailed exergy analysis highlights that the Kalina cycle's condenser contributes the most to exergy destruction, accounting for approximately 129.6 kW. Through a parametric study, it is revealed that the pressure of the production well significantly influences the performance indicators, and the price of electricity sold has a substantial impact on the system's payback period and net present value. Moreover, the application of a multi-objective optimization strategy leads to the identification of the system's optimal state through an exergo-economic assessment. This optimization yields an exergy efficiency of around 49.75 % and a sum unit cost of products of 8.56 $/GJ.

Thermodynamic and exergoeconomic assessment of a trigeneration system driven by a biomass energy source for power, cooling, and heating generation

Environmental concerns and the limitations of conventional energy drive the exploration of reliable renewable sources. Herein, a biomass-assisted trigeneration system in conjunction with a methane-fed gas turbine cycle for generating power, cooling, and heating, and an attempt has been made to maximize the energy extraction from the energy source. The proposed system includes a steam Rankine cycle, a gas turbine unit, and a Kalina subsystem, and is investigated from energetic, exergetic, and economic viewpoints. A comprehensive parametric evaluation is carried out, and a multi-objective grey wolf optimization algorithm integrated with the LINMAP decision-maker method is employed to detect the most optimum point through two different scenarios. By conducting a base study, a net output power of 5926 kW, cooling load of 36.56 kW, heating load of 843.4 kW, and an energetic efficiency of 47.41 % can be achieved. The exergetic and economic standpoints bring out an exergy destruction rate of 7697.07 kW, cycle exergetic efficiency of 41.44 %, and a net present value of 12.420 $M that sequels to a payback period of 5.56 years. Biomass proves reliable in multigeneration systems, emphasizing the pivotal role of studies in maximizing energy extraction for diverse product outputs.

Exergetic and exergoeconomic assessments of a diesel engine operating on dual-fuel mode with biogas and diesel fuel containing boron nitride nanoparticles

Exergetic and exergoeconomic assessments of a diesel engine operating on dual-fuel mode with biogas and diesel fuel containing boron nitride nanoparticles

Exergoeconomic assessment of a high-efficiency compressed air energy storage system

Energy storage systems have a critical part in enabling greater use of intermittent energy resources. For a sustainable energy supply mix, compressed air energy storage systems offer several advantages through the integration of practical and flexible types of equipment in the overall energy system. The primary advantage of these systems is the management of the duration of the peak load of multiple generation sources in ‘islanded operation’ without connection to the electricity network. Here, research introduces and analyzes a novel multigeneration system for electrical power, cooling, heating, potable water, sodium hypochlorite, and hydrogen production to improve the industrial aspects of the system for more profitability and efficiency with lower environmental impacts. The system involves three main sub-systems: CAES, combined cooling, heat & power, and a desalination unit. To assess the performance of the system, technical, economic, exergoeconomic, and exergoenvironmental studies are conducted. The results regarding the energy and exergy studies reveal that the system presents great potential for reliable operation during peak demand hours. The round-trip efficiency is 74.5 % producing 1721 kW of electrical power with concurrent cooling and heating loads at 272.9 and 334.6 kW, respectively. Economically, the levelized costs of heating/cooling, clean desalinated water, and electricity are 26.4 US$/GJ, 2 US$/lit, and 4.5 cents/kWh, respectively. Finally, the outcomes of the exergoenvironmental study display that the sustainability index for the system is 1.7.

Exergoeconomic assessment of a cogeneration pulp and paper plant under bi-operating modes

In the current study, the exergoeconomic analysis of a cogeneration pulp and paper plant under bi-operating modes at different environment temperatures of 290, 295, 305, 310, and 320 K was investigated. Two operating modes of the cogeneration system, i.e., a hybrid operating mode using a power boiler and a recovery boiler and a singular operating mode using a power boiler only, were considered. Natural gas was utilized as the main fuel in the power boiler, while black liquor with heavy fuel oil was employed in the recovery boiler. The total capital investment, total operating, exergy, unit exergy, and exergy destruction costs for each operating mode were evaluated. The results indicated that the total capital investment cost was 3420.27 $/h, and the total capital investment and the operation and maintenance costs in the hybrid and singular modes were 5853.27 and 6226.67 $/h, respectively. As well, the unit exergy cost and the exergy cost of steam introduced by the power boiler were 39.31 $/MWh and 2503.69 $/h, respectively. Where these values for the recovery boiler were 34.69 $/MWh and 554.30 $/h, respectively. Furthermore, the exergy destruction costs at an environment temperature of 320 K for the power and recovery boilers were 1436.6 and 213.63 $/h, respectively. In the hybrid mode, the soda at a 10% concentration was recovered, with a rate of 32 t per hour desired for the cooking process in the pulp mill. In addition, the use of black liquor as a bio-fuel in the recovery boiler saved 14% of the consumption of natural gas.

A new biomass-natural gas dual fuel hybrid cooling and power process integrated with waste heat recovery process: Exergoenvironmental and exergoeconomic assessments

The integration of gas turbine cycle (GTC)-based energy processes with a biomass gasification process employing a post-combustion approach, in addition to improving the reliability and performance of the energy cycle, can reduce the current crisis in the energy sector and balance the environmental impacts of the hybrid energy cycle. The present paper develops a multi-criteria evaluation and optimization of a novel hybrid cooling and power process (HCPP) based on GTC and post-combustion-based biomass gasification process integrated with downstream cycles. Two fuels (i.e., natural gas and biomass) are utilized simultaneously to produce energy in the proposed process. In addition, the downstream cycles are based on two organic Rankine cycles (ORCs) and a refrigeration unit to recover waste heat. The performance of the developed HCPP has been evaluated and discussed from the thermodynamic-conceptual, exergoenvironmental and exergoeconomic points of view. Additionally, a tri-objective optimization is applied to identify optimal inputs and outputs variables. The overall results indicated that the proposed HCPP can produce 13 MW of electric power and 7.6 MW of cooling load. The thermal and exergy efficiencies of the system were 70.1% and 42.85%, respectively. Moreover, the values of levelized cost of energy (LCOE) and product unit environmental impact (PUEI) were calculated as 0.0748 USD/kWh and 0.0184 Pts/kWh, respectively. However, under tri-objective optimization, the values of LCOE and PUEI can be reduced by approximately 9.4% and 16.8%. The effect of different parameters was also discussed and evaluated through a parametric analysis. Furthermore, the conceptual assessment and design of the solar field was developed for a hypothetical scenario and configuration (based on geographical conditions of a certain region).

Exergo–Economic and Parametric Analysis of Waste Heat Recovery from Taji Gas Turbines Power Plant Using Rankine Cycle and Organic Rankine Cycle

This study focused on exergo–conomic and parametric analysis for Taji station in Baghdad. This station was chosen to reduce the emission of waste gases that pollute the environment, as it is located in a residential area, and to increase the production of electric power, since for a long time, Iraq has been a country that has suffered from a shortage of electricity. The main objective of this work is to integrate the Taji gas turbine’s power plant, which is in Baghdad, with the Rankine cycle and organic Rankine cycle to verify waste heat recovery to produce extra electricity and reduce emissions into the environment. Thermodynamic and exergoeconomic assessment of the combined Brayton cycle–Rankine cycle/Organic Rankin cycle (GSO CC) system, considering the three objective functions of the First- and Second-Law efficiencies and the total cost rates of the system, were applied. According to the findings, 258.2 MW of power is produced from the GSO CC system, whereas 167.3 MW of power is created for the Brayton cycle (BC) under the optimum operating conditions. It was demonstrated that the overall energy and exergy efficiencies, respectively, are 44.37% and 42.84% for the GSO CC system, while they are 28.74% and 27.75%, respectively, for the Brayton cycle. The findings indicate that the combustion chamber has the highest exergy degradation rate. The exergo–economic factor for the entire cycle is 37%, demonstrating that the cost of exergy destruction exceeds the cost of capital investment. Moreover, the cost of the energy produced by the GSO CC system is USD 9.03/MWh, whereas it is USD 8.24/MWh for BC. The results also indicate that the network of the GSO CC system decreases as the pressure ratio increases. Nonetheless, the GSO CC system’s efficiencies and costs increase with a rise in the pressure ratio until they reach a maximum and then decrease with further pressure ratio increases. The increase in the gas turbine inlet temperature and isentropic efficiency of the air compressor and gas turbine enhances the thermodynamic performance of the system; however, a further increase in these parameters increases the overall cost rates.

Machine learning approach to predict the biofuel production via biomass gasification and natural gas integrating to develop a low-carbon and environmental-friendly design: Thermodynamic-conceptual assessment

A hybrid energy cycle (HEC) based on biomass gasification can be suggested as an efficient, modern and low-carbon energy power plant. In the current article, a thermodynamic-conceptual design of a HEC based on biomass and solar energies has been developed in order to generate electric power, heat and hydrogen energy. The planned HEC consists of six main units: two electric energy production units, a heat recovery unit (HRU), a hydrogen energy generation cycle based on water electrolysis, a thermal power generation unit (based on LFR field), and a biofuel production unit (based on biomass gasification process). Conceptual analysis is based on the development of energy, exergy and exergoeconomic assessments. Besides that, the reduction rate of pollutant emission through the planned HEC compared to conventional power plants is presented. In the planned HEC, when hydrogen energy is not needed, excess hydrogen is feed into the combustion chamber to improve system performance and reduce the need for natural gas. Accordingly, the rate of polluting gases emitted from the cycle can be mitigated due to the reduction of fossil fuels consumption. Further, based on the machine learning technique (MLT), the level of biofuel produced from the mentioned process is estimated. In this regard, two algorithms (i.e., Support vector machine and Gaussian process regression) have been employed to develop the prediction model. The findings indicated that the considered HEC can produce about 10.2 MW of electricity, 153 kW of thermal power, and 71.8 kmol/h of hydrogen energy. In both training and testing sets, the Support vector machine model exhibits better behavior compared the two Gaussian process regression model. Based on machine learning technique, with increasing gasification pressure, the level of biofuel obtained from the process does not increase significantly.

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.

Exergetic, enviroeconomic and exergoeconomic (3E) assessment of a stationary parabolic trough solar collector with thermal storage

A solar heating system operating in thermosyphon regime was experimentally evaluated in this study. The system consisted of a stationary parabolic trough solar collector (PTC) with thermal storage. The effect of three collector inclination angles (0°, +5°, and +10°) and two thermal fluids (water and thermal oil, denoted as WPTC0° and OPTC0°) were evaluated on the exergetic, enviroeconomic, and exergoeconomic (3E) performance of PTC. The average exergetic efficiencies for the evaluated cases were 10.84, 11.75, 12.97, and 19.73% for WPTC+10°, WPTC+5°, WPTC0°, and OPTC0°, respectively. It was observed that about 50% of the input exergy is lost in all cases evaluated, indicating that some improvements could be incorporated to recover part of this loss. WPTC0° had the lowest average destroyed exergy among the inclinations (35%). For the case using thermal oil, the average exergy destroyed was 28%. OPTC0° showed the best results in exergetic terms. OPTC0° also presented the highest values of the exergoeconomic parameter among all the evaluated cases, and WPTC0° presented the highest values among the evaluated inclinations. The energy and carbon payback times obtained were 0.848 and 0.569 for the WPTC0° and 0.923 and 0.608 for the OPTC0°, respectively.

Economic, Exergoeconomic and Exergoenvironmental Evaluation of Gas Cycle Power Plant Based on Different Compressor Configurations

The decision-making process behind the selection of a gas turbine engine (GT) is crucial and must be made in accordance with economic, environmental, and technical requirements. This paper presents the relevant economic, exergoeconomic and exergoenvironmental analyses for four GT engines with different compressor configurations. The GT engine configurations are identified according to the type of compressor: axial, axial-centrifugal, two-stage centrifugal, and centrifugal-centrifugal. The performances of the four GT engines were validated against manufacturer supplied data using specialized software. The economic analysis, a detailed life cycle costing considering the cost to be paid per unit net power obtained from the GT, and subsequent shortest payback period showed that the GT with centrifugal-centrifugal compressor was most economically feasible. This was followed, in order, by the GT-axial, GT-axial-centrifugal, and finally the GT-two-stage centrifugal configuration, where the cost of ownership for a 20 year plan ranges between 8000 USD/kW to about 12,000 USD/kW at different operational scenarios during the life cycle costing. Exergoeconomic assessment provided useful information to enhance the cost-effectiveness of all four systems by evaluating each component separately. The axial-centrifugal configuration registered the lowest CO2 emissions (about 0.7 kg/kWh); all environmental indicators confirmed it is the most environmentally friendly option.

Comprehensive analysis and multi-objective optimization of power and cooling production system based on a flash-binary geothermal system

The sustainable and environmentally-benign nature of geothermal energy motivates the current investigation to design a cogeneration of power and cooling system. The designed system consists of a double-flash binary system with an organic Rankine cycle and ejector refrigeration cycle integration as the waste heat recovery system. The subsystem's performance is enhanced through the zeotropic working fluid implementation. The energy, exergy, and exergo-economic assessments were utilized to compare two zeotropic mixtures' performances and select an appropriate working fluid. This comparison is carried out by comprehensive sensitivity analysis to study their performance under variable operational conditions. The results reveal that the Pentane-Isohexane has higher performance leading to 1.9 MW of net power and 290.15 kW of cooling load generation. Hence, the total exergetic efficiency and payback period are obtained to be 58.33% and 6.70 years. Considering the energy/economic optimization scenario enhances the cooling load generation to 574 kW and reduces the net power to 1.85 kW, while the exergy/economic scenario increases the net power production to 1.99 MW and declines the cooling load. By considering the overall performance indexes, the exergy/economic scenario with 6.56 years payback period provides a higher performance and the best optimization scenario.

Development, exergoeconomic assessment and optimization of a novel municipal solid waste-incineration and solar thermal energy based integrated power plant: An effort to improve the performance of the power plant

Due to the growing population rate and increasing social activities, the content of municipal solid waste (MSW) production is increasing. Energy production from MSW is one of the promising ways to dispose of waste and reduce the limitations of fossil energies. However, this technology has a relatively low efficiency due to the high volume of moisture and inert materials in MSW and the lower heating value of waste. The integration of solar thermal collectors is one of the suggested solutions to increase the temperature of inlet steam to the power generation cycle in order to improve the power plant performance. In this regards, the present study develops a comprehensive thermodynamic-conceptual and exergoeconomic investigation of the performance of a MSW-incineration (MSWI) plant integrated with a parabolic trough collector (PTC)-based solar field. Accordingly, the temperature of the steam elevates by the solar field before entering the electric power generation cycle. Additionally, the solar unit is integrated with a phase change material (PCM)-based storage system. The use of storage tank at the delivery line of PTC can improve the power plant’s reliability. A comprehensive comparison of the developed power plant with the conventional MSWI power plant is presented. In addition, the technical and economic behaviors of the considered power plant have been optimized under two different single and multi-objective optimization scenarios. The outcomes indicated that the developed power plant can provide 15.75% and 15.68% higher energetic and exergetic efficiencies compared to MSWI power plant. In addition, the rate of electric power obtained from S-MSWI power plant is almost 16.1% more compared to MSWI power plant. However, the total cost rate of MSWI plant is almost 24.13% lower compared to the developed power plant. But, the value of LCOE in the developed power plant is approximately 8.93% lower than MSWI power plant. It was also found that, the multi-objective optimization can provide better and optimal results to energy engineers and decision makers compared the single-optimization. The conceptual design of the implementation of the solar field is also developed in a specific geographical condition. Additionally, this research comes from the key technology of the National Key Laboratory of Environmental Protection.