Multi-effect Desalination Research Articles

Operating Energy Needed for Desalination Systems in Cogeneration Plants

This study investigated the energy requirement for running desalination units coupled to cogeneration plants. Various cogeneration systems were explored using power- and heat-allocated approaches. The specific work and heat necessary for operating different desalination systems were determined. The investigation revealed that the specific work and heat remain consistent regardless of the desalination daily capacity. It was observed that the energy demand for operating a desalination system mainly relies on power plant efficiency. The investigation revealed that the energy demand for a plain multi-effect desalination system was lower than that for multi-effect desalination with thermal vapor compression. Additionally, the energy requirement for a multi-effect desalination system with preheaters was lower than that for plain multi-effect desalination. Comparisons also indicated that the energy demand of multi-stage flash exceeds that of different multi-effect desalination systems. Based on the primary thermal energy input, a universal performance ratio was used to evaluate the desalination unit performance. Furthermore, a new correlation was proposed to predict the universal performance ratio.

Triple-objective optimization using ANN+NSGA-II for an innovative biomass gasification-heat recovery process, producing electricity, coolant, and liquefied hydrogen

A novel thermal integration approach is introduced for a biomass-driven gas turbine power plant that generates electricity, coolant, and liquefied hydrogen. The designed scheme encompassed an organic flash cycle, a bi-evaporator ejector refrigeration unit, a high-temperature water electrolyzer for hydrogen production, a multi-effect desalination cycle for supplying water for electrolysis process, and a Claude cycle for hydrogen gas liquefaction. The designed system's importance comes back to using biomass feedstock as the input fuel and utilizing the hydrogen liquefaction method. In addition to the possibility of deploying the system in remote areas, it provides the opportunity for hydrogen storage in a smaller volume for more accessible storage and transportation. On the other hand, using a comparative method for selecting an environmentally friendly fluid for the heat recovery subsystem is another crucial aspect of the present study from the environmental aspect. It is found that R161 is the appropriate choice among the seven studied working fluids. Subsequently, a comprehensive evaluation of the entire system's thermodynamic and environmental aspects is performed using an intelligent process. By considering energy and exergy efficiencies along with CO2 emissions as the objective functions, a thorough sensitivity analysis and a triple-objective optimization are carried out. Hence, artificial neural networks for the objectives are developed and integrated into the NSGA-II optimization method. Employing LINMAP decision-making, the values of objective are attained, exhibiting 39.6 % for energy efficiency, 36.1 % for exergy efficiency, and 631.7 kg/MWh for CO2 emissions. Considering the optimum solution, the proposed system is capable of producing electricity, cooling, and liquefied hydrogen with capacities of 4526 kW, 1875 kW, and 21.22 m3/day, respectively. Additionally, the scenario yields an exergoenvironmental index of 0.579 and an exergetic stability index of 0.61. and a liquefied hydrogen generation rate of 21.22 m3/day.

Machine learning assisted improved desalination pilot system design and experimentation for the circular economy

Desalination is among the most feasible solutions to supply sustainable and clean drinking water in water scarcity areas. In this regard, Multi-Effect Desalination (MED) systems are particularly preferred for harsh feeds (high temperature and salinity) because of their robust mode of operation for water production. However, maintaining the efficient operation of the MED systems is challenging because of the large system design and variables' interdependencies that are sensitive to the distillate production. Therefore, this research leverages the power of machine learning and optimization to estimate the optimal operating conditions for the maximum distillate production from the MED system. In the first step, detailed experimentation is conducted for distillate production against hot water temperature (HWT) varying from 38 to 70 °C, and feed water temperature (FWT) is changed from 34 to 42 °C. Whereas, the feed flow rate (FFR) is investigated to be varied nearly from 3.6 to 8.7 LPM in the three stages, i.e., FFR-S1, FFR-S2 and FFR-S3. The compiled dataset is used to make the process models of the MED system by three ML-based algorithms, i.e., Artificial Neural Network (ANN), Support Vector Machine (SVM), and Gaussian Process Regression (GPR) under rigorous hyperparameters optimization. GPR exhibited superior predictive performance than those of ANN and SVM on R2 value of 0.99 and RMSE of 0.026 LPM. Monte Carlo technique-based variable significance analysis revealed that the HWT has the highest effect on distillate production with a percentage significance of 95.6 %. Then Genetic Algorithm is used to maximize the distillate production with the GPR model embedded in the optimization problem. The GPR-GA driven maximum distillate production is estimated on HWT = 70 ± 0.5 °C, FWT = 40 ± 2.5 °C, FFR-S1 = 6 ± 2.6 LPM, FFR-S2 = 7 ± 1 LPM and FFR-S3 = 7 ± 1. The ML-GA-based system analysis and optimization of the MED system can boost the distillate production that promotes operation excellence and circular economy from the desalination sector.

Can injecting additional green hydrogen result in environmentally friendly solar-biomass integration? Comprehensive comparison and multi-objective optimization

The present work proposes an innovative system for decarbonizing the energy mix and accelerating the worldwide green transition process. The system is driven by a biomass digester integrated with the supercritical carbon dioxide cycle for power generation and a multi-effect desalination unit for drinkable water production. At the heart of this concept is additional hydrogen injection through a proton exchange membrane electrolyzer based on photovoltaic panels. The suggested innovative model's techno-environmental, sustainability, and economic aspects are assessed and compared with a similar system without hydrogen injection. Then, a comparative multi-criteria optimization is applied to find the most optimal conditions from various facets based on the genetic algorithm with machine learning techniques. Afterward, the system’s performance at different optimal conditions is analyzed and compared by evaluating the most significant techno-economic, environmental, and sustainability indicators. The parametric assessment comparing different models indicates that the proposed novel model, including increased hydrogen injection, surpasses the basic system in terms of performance efficiencies, emissions, and energy costs. In the first optimization scenario, the proposed method demonstrates robustness by achieving higher water production of 1456 kg/s, a lower total cost of 118 $/h, and a higher net power of 1.1 MW than the design condition. When considering the sustainability index, energy cost, and emission metric as the optimization objective, their values are altered from 0.81 to 0.85, 92.5 $/MWh to 89.7 $/MWh, and 64.2 kg/MWh to 53.6 kg/MWh. The results further show that when prioritizing the sustainability index, energy cost, and emission as objectives, all components perform better from the energy conversion quality aspect compared to the scenario where water production, total cost, and net power are the optimization objectives. Finally, it is observed that the combustion chamber and solar panels are the worst components from the irreversibility aspect because of the highest exergy destruction rate.

Evaluation of mechanical vapor recompression and easy multi-effect desalination systems in different climate conditions-sensitivity and 7E analysis

Evaporative desalination systems, such as Multi-Effect Desalination (MED) and Mechanical Vapor Recompression (MVR), play important roles in addressing this challenge. Although large-scale desalination systems possess limitations in catering to the water demands of remote regions and islands and entail the cost of water transportation to residential areas, it is imperative to concentrate on studying the feasibility of employing centralized evaporative water production systems. Firstly, in this study, the initial focus is on conducting energy and exergy analyses of MVR and Easy MED systems, with a goal of enhancing knowledge about the energy consumption, exergy destruction and exergetic efficiency of these systems. Secondly, an economic analysis is undertaken to assess the feasibility of deploying these systems in various global regions. The analysis takes into account different geographical and techno-economic conditions, such as sea water temperature, interest rates, and electricity costs. This investigation also aims to explore variations in Annual Operative Cost (AOC), Total Annual Cost (TAC) and the cost of fresh water across these diverse regions. Thirdly, a sensitivity analysis is performed for the economic assessment of MVR and Easy MED systems. Lastly, exergoeconomic, environmental, enviroeconomic and exergoenvironmental analyses are conducted for both of these systems. The results show that the exergy efficiency of the Easy MED system surpasses that of the MVR, whereby the exergy destruction for Easy MED and MVR are recorded to be 5460 W and 6360 W respectiveyl. In addition to this, the MVR system demonstrated a higher TAC across all cities. The freshwater production cost of the Easy MED system was less expensive than of the MVR system. Perth was the most cost-effective city, with freshwater costs of 6.8 €/m3 and 11.91 €/m3 for MVR and Easy MED systems, respectively. Further to this, sensitivity analysis revealed that both systems are sensitive to fluctuations in electricity costs and seawater temperatures. The MVR system incurred higher fuel, product, and exergy destruction costs. However, the MVR system also exhibited greater environmental friendliness due to its lower emission of pollution gases.

An innovative geothermal based multigeneration plant: Thermodynamic and economic assessment for sustainable outputs with compressed hydrogen

In the net-zero emissions strategy adopted to struggle global warming and environmental difficulties, the effective utilization of clean energy sources is important. In this framework, geothermal sources are an important renewable energy sources and offer many advantages. In the developed new research, a geothermal energy-supported combined configuration is considered and proposed for sustainable hydrogen, power, freshwater, hot water, and drying. In this system, an exhaustive thermodynamic examination, -energy, exergy efficiency, and exergy destruction-, as well as an economic analysis are carried out. This newly designed configuration comprises a flash-geothermal circuit, a transcritical CO2 fluid Rankine plant (tRC), a dryer, a multi-effect desalination (MED) component, and a Proton exchange membrane (PEME) and hydrogen storage units. In light of the analysis outcomes, the power generation load of the system is 1587 kW and the hydrogen quantity is calculated 0.00223 kg/s. In addition, the thermodynamic performance indicators, which are energetic and energetic performance of the tRC are determined as 10.91% and 41.68%. Moreover, the energetic efficiency of the modeled configuration is determined to be 23.18%, whereas the exergetic performance indicator is found to be 28.57%. Regarding the economic cost evaluations, the total cost of this model is calculated as 171.5 $/h.

Thermodynamic and thermoeconomic analysis and optimization of a renewable-based hybrid system for power, hydrogen, and freshwater production

To address environmental pollution effectively, it is crucial to promote the increased utilization of renewable energy sources. Furthermore, an appealing opportunity arises from enhancing the efficiency of renewable-based power plants while diversifying their product output. This study introduces a hybrid system that revolves around renewable resources, with a primary focus on evaluating power generation, hydrogen production, and freshwater extraction. The designed system seamlessly integrates a flash-binary geothermal power plant with a solar system, incorporating cutting-edge phase-change material storage technology. Hydrogen is generated through a combination of steam-methanol reforming and pressure swing adsorption processes. Freshwater is procured utilizing humidification-dehumidification and multi-effect desalination units. In terms of power generation, the system leverages the capabilities of the geothermal power plant alongside a modified Kalina cycle. The performance of this integrated system is rigorously evaluated through a combination of thermodynamic and thermoeconomic approaches. An exergy-economic optimization scenario is employed to determine the most efficient operational mode. The results of this comprehensive analysis reveal that the system can produce 0.0224 kg/s of hydrogen, 8.017 kg/s of freshwater, and generate 215.9 W of net power. Impressively, it achieves an exergy efficiency of 58.3% at a unit cost of $32.23/GJ in the base mode. Furthermore, the optimal operating state boosts efficiency to 60.59%, with a unit cost of $32.22/GJ. Notably, adjustments in the selling price of hydrogen have a significant impact on the system's financial metrics. As the price of hydrogen rises from $5 to $6/kg, the payback period reduces from 4 to 3 years, and the net present value surges from $5.81 million to $10.16 million.

Eco-friendly multi-heat recovery applied to an innovative integration of flue gas-driven multigeneration process and geothermal power plant: Feasibility characterization from thermo-economic-environmental aspect

Sustainable production presents a viable approach that provides an environmentally friendly and integrated method for polygeneration objectives. This method can make the most significant impact in improving the effectiveness of conventional power plants. Furthermore, using renewable energy sources to modify the configuration of conventional power plants is imperative for implementing this methodology. Therefore, the primary objective of this research is to suggest a new method for attaining sustainable production in a power plant by integrating an environmentally friendly multi-heat recovery system. This innovative system allows for the efficient use of the power plant's flue gas for a polygeneration process and a geothermal power plant. The integrated setup comprises various components such as a multi-effect desalination unit, a proton exchange membrane electrolyzer, a cooling and heating generation subsystem, a liquefied natural gas regasification unit, a geothermal-based subsystem utilizing a flash-binary geothermal power plant, a Kalina cycle, and a heating generation unit. The study simulates this process using Aspen HYSYS software and conducts a comprehensive energy, exergy, economic, and environmental analysis. According to the results, the assessment reveals that the total energy and exergy efficiencies amount to 64.82% and 88.57%, respectively. The energy cost index is recorded at 0.028 $/kWh, alongside a specific CO2 emission of 0.211 kg/kWh. This value shows a notable reduction of 59.33% compared to a system reliant on biomass fuel. Parametric assessments are additionally conducted, whereby variations in performance metrics are predicted to exhibit the process performance.

Performance evaluation and optimization of a multigeneration hybrid system for power, hydrogen, cooling, and freshwater production from renewable sources

Designing a hybrid system emerges as a highly efficient strategy for augmenting the performance of renewable-based power plants, owing to their adaptability in integrating diverse subsystems. In this study, a new multigeneration system is introduced, showcasing its capability to concurrently generate power, hydrogen, cooling, and freshwater through a synergy of methanol-steam reforming, modified absorption refrigeration cycles, humidification-dehumidification, and multi-effect desalination. The operational foundation of the system is rooted in the harmonious integration of solar and geothermal energy sources. To comprehensively evaluate the proposed system's performance, a combination of exergy and economic analyses is employed. This research studies the impacts of varying key parameters on the system's operation. Notably, the water-to-methanol ratio is identified as the most influential variable affecting reformer performance, underscoring the pivotal role of reforming pressure. The estimated total fixed cost of the system stands at $4.039 million, with a calculated payback period of 6 years and a net present value of $3.454 million. Furthermore, in its optimized state, the system achieves an impressive exergy efficiency of 49.80 % and a unit product cost of $32.38/GJ. These findings unequivocally validate the feasibility and economic viability of the proposed hybrid renewable-based power generation system. In conclusion, the amalgamation of solar and geothermal energy, coupled with meticulous parameter optimization, substantiates the potential of this innovative system to serve as a sustainable and economically viable solution for power generation.

Comprehensive optimization of an integrated energy system for power, hydrogen, and freshwater generation using high-temperature PEM fuel cell

Modern energy conversion technologies with low or no emissions are needed to achieve sustainable development goals. This research examines the thermodynamic and exergy-economic features of a high-temperature proton exchange membrane fuel cell. A cutting-edge, integrated energy system uses high-temperature proton exchange membrane fuel cells, an organic Rankine cycle, a proton exchange membrane electrolyzer, and a multi-effect desalination unit. This setup generates electricity, hydrogen, and fresh water. Methanol-steam reformation produces hydrogen for the fuel cell. The recommended cycle drives an organic Rankine power producing cycle using 120–200 °C waste heat from high-temperature proton exchange membrane fuel cell to power water electrolysis and hydrogen generation. An integrated method incorporates energy and exergy balances and cost analysis to assess the proposed system's exergetic, economic, and environmental impacts. The suggested integration delivers high energy and exergy efficiency at an acceptable cost and environmental effect. According to parametric research, boosting the fuel cell's working temperature decreases production costs and carbon dioxide emissions per mass. Raising current density has positive technical and environmental impacts. As the current density increases from 0.4 to 0.8 (A/cm2), the net power generation increases to 46.67% and the exergy efficiency increases from 64.5% to 68%. An increase in multi-effect distillation motivate steam pressure from 200 to 600 kPa results in an increase in the daily freshwater generated from 111.68 m3 to 116.41 m3. For environmental protection and output optimization, fuel utilization ratio must be reduced. The ideal system's exergy efficiency, product unit cost, and environmental impact are 65.78%, 86.28 ($/h), and 4.33%, respectively.

Production of power and fresh water using renewable energy with thermal energy storage based on fire hawk optimization

This manuscript proposes an optimization method for power production and fresh-water using renewable sources with thermal energy storage (TES). The proposed method is the fire hawk optimization (FHO) method. The objective of the proposed method is to find better thermal efficiency. The waste heat in the steam power plant is converted to fresh water using the multi-effect desalination method. The cost of freshwater strongly depends on solar-electricity cost and displays a significant variation because of the variable solar availability state. The integrated structure using thermodynamics is examined by Exergy analysis. Heat exchangers and collectors are related to the energy efficiency of the total integrated structure and the equipment’s highest share of energy destruction. The FHO method is implemented in MATLAB and its execution is calculated with existing approaches. The thermal efficiency in solar collectors is 80% and it is better than existing methods.

Comprehensive analysis and optimization of a low-carbon multi-generation system driven by municipal solid waste and solar thermal energy integrated with a microbial fuel cell

Abstract In this article, a novel multi-generation plant is addressed and assessed from the energy, exergy, exergoenvironmental and exergoeconomic points of view. The multi-generation plant is composed of two main units: one unit for energy production and another unit for carbon capture and methanol synthesis. Biomass fuel, solar energy and seawater are the main nutrients in the plant. Steam, Brayton, organic Rankine and Kalina cycles have been employed to generate electricity. A linear Fresnel collector-driven solar farm is considered as an auxiliary heat source. In addition, an integrated desalination unit based on a multi-effect desalination unit, a microbial fuel cell and a reverse osmosis unit has been installed in the multi-generation plant. The proposed structure for the offered multi-generation plant is designed under a new configuration and layout that had not been reported in the publications. From the outcomes, the multi-generation plant can produce 69.6 MW of net electricity, 0.53 kg/s of methanol, 0.81 kg/s of oxygen gas, 73.8 kg/s of fresh water and ~0.015 kg/s of hydrogen gas. Under such performance, the offered multi-generation plant can be 51.72 and 27.5% efficient from the points of view of energy and exergy, respectively. Further, the total cost rate and environmental impact of the plant are ~3378 US$/h and 294.1 mPts/s, respectively. A comparative analysis is developed to exhibit the superiority of the planned multi-generation plant. A five-objective optimization is also developed to achieve the optimum design data and outcomes of the plant.

Exergoeconomic and exergoenvironmental analyzes of a new biomass/solar-driven multigeneration energy system: An effort to maximum utilization of the waste heat of gasification process

In addition to improving the sustainability and thermodynamic efficiencies of an energy conversion system, a solar/biomass-driven integrated energy system can also reduce environmental impacts. The current work presents a detailed evaluation (thermodynamic simulation and exergoenvironmental and exergoeconomic analyzes) of a solar/biomass-powered multigeneration energy system (MGES). Accordingly, four units were considered for electric power generation. A linear Fresnel concentrator (LFC)-driven solar farm, a municipal solid waste (MSW) gasification cycle, an alkaline water electrolyzer (AWE) unit (to produce hydrogen gas), and a multi effect desalination (MED)-based Seawater desalination cycle are also considered in the MGES. A multi-objective optimization (regarding the technical, cost, and environmental objective functions) was also developed for the offered MGES. The proposed configuration for the MGES has a new components process that had not been reported in the publications. The power generation level was improved by utilizing the energy available in waste heat in the different downstream units. The offered MGES can generate 154.1 MW of electrical power, ∼ 280 kg per day of hydrogen gas, and 265.4 m3/h of fresh water. Meantime, the offered MGES can 38.8 % and 32.2 % efficient in terms of energy and exergy, respectively. Besides, the LCOE value and the environmental impacts index for the offered MGES were approximately 3.82 USD/GJ and 0.545 Pts/GJ, respectively. Also, raising the syngas temperature at the inlet of the combustion chamber can be a reasonable decision from the exergetic, economic and (especially) environmental standpoints.

Sustainable development and multi-aspect analysis of a novel polygeneration system using biogas upgrading and LNG regasification processes, producing power, heating, fresh water and liquid CO2

Considering biogas upgrading to feed energy systems and its significant impact on the biogas energy density, a novel polygeneration system utilizing biogas from landfill waste is designed, simulated, and studied in this paper. The primary innovation is to design a biogas upgrading technology for a novel multigeneration system using a thermal matching approach. This system is capable of simultaneously generating power, providing heating, producing fresh water, and extracting liquid carbon dioxide in an environmentally sustainable manner, thus resulting in reduced environmental impacts. For this purpose, a cryogenic separation system based on liquefied natural gas cold utilization is employed for biogas upgrading and biomethane separation. The proposed process also consists of a Kalina cycle, an organic Rankine cycle, a multi-effect desalination technology, and a heating provider unit. This system is simulated within the Aspen HYSYS software and is undergone a comprehensive analysis from the viewpoints of energy, exergy, environmental, and economic. The results indicate that the proposed structure achieves energy and exergy efficiencies of 80.91% and 43.76%, respectively. Environmental assessment reveals that the emission intensity is 90.43% lower in polygeneration mode compared to power generation mode, and the system’s net emission is equal to 23,041.51 kg/h. The economic evaluation demonstrates that the total unit cost of products is minimized in polygeneration operation (1.84 $/GJ), while it is highest in power generation condition (7.564 $/GJ). The investigations show that when a system is modified from a single generation to polygeneration, all thermodynamic, economic, and environmental indicators face an improvement.

A comprehensive and comparative study of an innovative constant-pressure compressed air energy storage (CP-CAES) system

Electricity and potable water are two vital resources for the world's population. A pioneering green energy storage system for power and potable water production has been introduced and investigated in this context. The innovative system integrates compressed air, pumped hydro, and thermal energy storage, along with multi-effect desalination. This combination enables the generation of power and potable water without exerting any adverse impact on the environment. This technology manages the start-up time of the desalination unit by using a low thermal energy storage unit and allows potable water to be generated throughout the day. By conducting a comprehensive analysis including energy, exergy, economic, and exergoeconomic, the performance of the system has been carefully examined and the effect of various parameters has also been considered. Finally, the advantages of the proposed system are compared to the conventional system. According to the study, round trip efficiency and total cost rate have been calculated as 62.18% and 618.6 USD/hr, respectively. Based on a case study conducted in the coastal areas of the state of California, the proposed system has the potential to generate 138 m3 of potable water and 88.11 MWh of electricity per day. This could lead to a total profit of 27.65 million dollars with a payback period of 3.82 years.

Optimizing solar-driven multi-generation systems: A cascade heat recovery approach for power, cooling, and freshwater production

The pursuit of an optimal solution for performance is essential in ensuring that a solar-driven multi-generation system functions efficiently. Due to the vast amount of solar power received by such systems, the production of significant waste heat ensues. Therefore, this study aims to propose and optimize a new cascade heat recovery method for a solar system that generates power, cooling, and freshwater. The designed configuration encompasses a parabolic trough solar collector to supply the required input energy of integration of a dual-pressure organic Rankine cycle with an ejector refrigeration cycle and an integration of a steam power cycle with a thermal vapor compression- multi-effect desalination. Employing both thermodynamic and economic assessments leads to attaining the performance indexes, which are involved in the optimization procedure. The outcomes of the simulation reveal that the net power, cooling, and freshwater productions are attainted at about 12.56 MW, 2.01 MW, and 138.3 kg/s. Also, the mass fraction 0.5–0.5 is an ideal composition for the highest values of net power and exergy efficiency, and these indexes are highly sensitive to changes in the temperature of vapor generator 3. The optimal operation mode provides an exergy efficiency of 14.76 % and a payback period of 5.49 years. In conclusion, the proposed cascade heat recovery method not only enhances the overall efficiency of the solar-driven multi-generation system but also demonstrates economic viability with a reasonable payback period.

Development, 4E-analysis, and optimization of a seawater thermal energy-driven desalination system based on seawater source heat pump, multi-effect desalination, and pressure retarded osmosis with reduced effluent concentration

Development, 4E-analysis, and optimization of a seawater thermal energy-driven desalination system based on seawater source heat pump, multi-effect desalination, and pressure retarded osmosis with reduced effluent concentration

New procedure for an optimal design of an integrated solar tower power plant with supercritical carbon dioxide and organic Rankine cycle and MED-RO desalination based on 6E analysis

In this paper, an innovative structure for the production of electricity and freshwater in Kangan Port, located in southern Iran and close to the Persian Gulf, is developed and analyzed. Heliostat collectors are employed in this process to provide the necessary thermal energy in the supercritical carbon dioxide (S-CO2) cycle, the organic Rankine cycle (ORC) and desalination unit. Additionally, implementing the current multi-effect desalination (MED) processes unit with the reverse osmosis (RO) system as well as employing the sun's thermal collector field to enhance the system's achievement and propose the best plan for the unit that operates has been looked into. ASPEN HYSYS software, Meteonorm package, and MATLAB programming are used to simulate the proposed system. Concurrently, this integrated power plant exhibits the capacity to simultaneously generate 117 kg/s of freshwater and yield 25.14 MW of power. The integrated structure has a thermal efficiency of 36% and a overall exergy efficiency of 31.99. Exergy study reveals that heat exchanger 8 and turbine 3 experience the most exergy destruction. To recover lost heat and produce additional electricity, organic Rankine cycle are used. Investigations are done on seven organic fluids in the ORC unit. The system is better understood from several views with the assistance of energy, exergy, exergoeconomic, exergoenvironmental, emergoeconomic, and emergoenvironmental (6E) analyses. In this regard, m-file codes in MATLAB programming for 6E analyses are developed. The generated code's thermodynamic simulation is accurately compared to ASPEN HYSYS software. Additionally, sensitivity analysis depending on the primary parameters is carried out. For a thorough study of each component, advanced exergy-based analysis linked to avoidable/endogenous and unavoidable/exogenous segments is carried out. The objective functions and chosen variables are optimized using a genetic algorithm. The best organic fluid in terms of thermodynamics is n-hexane and the ideal organic fluid from an economic and environmental standpoint stands R-113. The overall system's cost rate and environmental impact are obtained at 0.1679 $/s and 0.000545 pts/s, respectively.

Development of a hybridized small modular reactor and solar-based energy system for useful commodities required for sustainable cities

The current study develops a hybridized small modular nuclear reactor and solar-based system designed specifically for sustainable communities in metropolitan areas to meet their power, heat, clean fuel, fresh water and food requirements. Both floating-type and bifacial-type photovoltaic arrays are integrated with a high-temperature gas-cooled small modular reactor. In the integrated system, a Rankine cycle subsystem for power generation, a solid oxide electrolyzer for hydrogen production, a pressure swing adsorption unit with ammonia reactor for nitrogen and then ammonia production, a multi-effect desalination unit for freshwater generation, and heat recovery units in order to provide heating to residential area, food drying facility, greenhouse, and fish farm facilities. For both floating and bifacial PV options, the 120 MWp PV modules are considered and integrated with two small modular reactor units at 250 MWth capacities each, 500 MWth in total. A thermodynamic analysis, which is based on energy and exergy approaches, is carried out. The time-dependent analyses are carried out for floating-type PV and bifacial-type PV options for the cities of Istanbul in Turkey; Barcelona in Spain; Los Angeles (LA) in the United States; Tokyo in Japan; and Toronto in Canada by using their hourly meteorological data, source and load capacities in a typical meteorological year. Among ten cases, between 112835 and 146180 tonnes of ammonia are generated in a typical year while meeting the heating and power requirements of sustainable communities in metropolitan areas. Among ten cases, the average overall energy and exergy efficiencies are found as 41.04% and 46.88%, respectively. The hybridization of such nuclear and solar systems achieves unique advantages by preventing intermittencies compared to the renewable-alone systems, reducing carbon emissions compared to fossil-based systems, and lowering the levelized costs of energy compared to the nuclear energy-alone systems.

Improving the photovoltaic/thermal (PV/T) system by adding the PCM and finned tube heat exchanger

In this study, we aimed to improve the performance of the photovoltaic-thermal (PV/T) system by incorporating phase change material (PCM) into the heat exchanger. A new design for the finned tube heat exchanger layout was introduced, and a comprehensive mathematical model was developed to analyze the heat transfer process and operational efficiency of the PV/T system. The temperature variation of the PV/T system was simulated and validated using real climatic conditions in Baghdad and Tehran. To conduct our analysis, we utilized the OpenFOAM software and enhanced our solver to accurately capture the melting process in the PCM. We also investigated the effects of wind velocity and atmospheric pressure on the performance of the PV/T system. Our findings showed that an increase in wind velocity led to an increase in PV/T efficiency, while an increase in atmospheric pressure resulted in a decrease in efficiency. Additionally, we observed that the Baghdad climate was more sensitive to variations in wind velocity compared to Tehran. In Baghdad and Tehran, the highest obtained water temperatures were 54.3 and 50.1 °C, respectively. Furthermore, a study was conducted to assess the viability of using PV/T (photovoltaic-thermal) technology for hot water production in the Multi-Effect Desalination and Adsorption Desalination cycle. The proposed PV/T system demonstrated an average performance improvement of 26% compared to traditional PV/T systems. During warmer months, the system was capable of producing 0.11 and 0.10 m3/h of potable water per month in Baghdad and Tehran, respectively. Furthermore, the system had the potential to generate 170 and 140 kW h of electricity for the respective cities.