Multi-effect Desalination System Research Articles

Development and assessment of a floating photovoltaic-based hydrogen production system integrated with storage options

The integrated system approach utilized in the current study represents an innovative approach to harnessing solar energy through a floating photovoltaic-based integrated plant featuring a diverse array of energy storage options. As part of this research, a solar energy system integrating both floating and concentrating solar technologies was designed at the specified site. Despite the constraints presented by the cold temperature at the chosen location, particularly during the winter months when solar irradiation is restricted, strategies are employed, such as exploiting the high albedo effect caused by the freezing of the water body, optimizing the application of solar radiation, and assuring the system's resilience and energy efficiency. Floating photovoltaic and concentrated solar panels are integral components of this advanced system, which is supplemented by underground hot and cold storage units, underground hydro-pumped storage, a multi-effect desalination system with freshwater storage, a lithium bromide absorption cooling system, and an alkaline electrolysis system for hydrogen and oxygen storage. This comprehensive energy strategy includes diverse storage and production technologies. The thermodynamic analyses and assessments employing the Engineering Equation Solver and the System Advisor Model provide some quantitative performance evaluations. The study considers time-dependent operational characteristics, illustrates the water withdrawal rates, energy and exergy efficiencies of the heating space temperature, inverter efficiency, GHI irradiance, mass, and volume values of the heat transfer fluid in both hot and cold tanks within thermal energy storage, annual cooling generation over a year, power production, hydropower storage, and hydrogen storage over a year. The system's concentrated solar panels are projected to generate an annual AC output of 180.79 GWh, with a yearly water usage of 14,055 m3, while floating panels are predicted to provide 7000 kWh with a 0.85 performance ratio. The overall energy efficiency of the current system is determined to be 51.76 %, and the exergy efficiency is found to be 55.41 %, respectively. Optimizing energy efficiency, utilizing diverse storage solutions, and utilizing aquatic environments minimizes environmental impact, and time-dependent analysis enhances perceptions of performance throughout different times and circumstances.

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.

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.

Solar driven desalination system for power and desalination water production by concentrated PVT and MED system

Abstract In this paper, a thermodynamic study of the combination of Concentrated Photovoltaic Thermal (CPVT) and Multi Effect Desalination (MED) system was conducted. CPVT produces electricity, and the heat produced in CPVT is used for the MED system. Engineering Equation Software (EES) was utilized to simulate this system. The effect of CPVT parameters (area, concentration ratio, and average solar radiation) and MED parameters (effect number and temperature of heating steam) were investigated on the produced heat, produced power, exergy destruction, total mass flow rate (FR) of desalinated water, total FR of feed water, heating steam FR and total brine FR. The range of changes for CPVT surface, concentration ratio, and average solar radiation was considered from 2000 m2 to 20000 m2, from 5 to 15 and from 400 W/m2 to 1100 W/m2, respectively. Based on obtained results, as the surface area of the solar panel, the ratio of concentration, and average solar radiation increase, the heat produced increases. Transferring this heat to the MED unit increases the total FR of desalinated water. But it has no significant effect on the Gain ratio (GOR). As the surface area of the solar panel increases from 10000 m2 to 12000 m2, the average radiation intensity increases from 800 W/m2 to 1000 W/m2, and the concentration ratio increases from 10 to 12 in effect the number of 4 and steam temperature of 70 °C, the total mass FR of desalinated water increases by 29 %, 23 %, and 20 %, respectively.

Energy and exergo-economic analysis of a parallel feed multi-effect system integrated with humidification–dehumidification system for brine recovery

Desalination technologies reject large amounts of brine with significant value back to sea. The concept of hybridization of different desalination technologies has proven that it can be effective in terms of reducing rejected brine and increasing the freshwater production rate as well as reducing the freshwater cost. In this work, brine recovery to improve water production through a simple modified configuration of integrating a multi-effect desalination (MED) system with humidification–dehumidification system (HDH). The rejected brine of the MED system is used as the feed for the HDH system without the need for preheating the rejected brine since it leaves the MED at a suitable temperature for HDH application. The study focuses on investigating the effect of different operating conditions on the increase in system freshwater production rate and recovery ratio as well as the exergetic efficiency. Parameters investigated include steam temperature, feed salinity, number of brine streams, cooling water flow rate, and ambient temperature. An exergo-economic analysis has also been conducted using the cost flow method to evaluate the freshwater production cost for the modified system. Results indicate that the integration of HDH can increase the water production rate by a maximum of 7.82% and produce fresh water at 2.08 $/m3 compared to 2.094 $/m3 when using the standalone system under the same conditions.

Techno-economic optimization and Nox emission reduction through steam injection in gas turbine combustion chamber for waste heat recovery and water production

Considering the persistent human need for electricity and fresh water, cogeneration systems based on the production of these two products have attracted the attention of researchers. This study investigates a cogeneration system of electricity and fresh water based on gas turbine (GT) as the prime mover. The wasted energy of the GT exhaust gases is absorbed by a heat recovery steam generator (HRSG) and supplies the superheat steam required by the steam turbine (ST). In order to produce fresh water, a multi-effect desalination (MED) system is applied. The motive steam required is provided by extracting steam from the ST. In order to reduce the environmental pollution of this cogeneration system, the steam injection method is proposed in the GT's combustion chamber (CC). This system is optimized by a multi-objective optimization tool based on the Genetic Algorithm (GA). The design variables include pressure ratio of compressor (CPR), inlet temperature of gas turbine (TIT), steam injection mass flow rate in the CC, HRSG operating pressure, HRSG evaporator pinch point temperature difference (PPTD), steam pressure of the MED ejector, ejector motive steam flow rate, number of MED effects, and return effect. The goals are to minimize the total cost rate (TCR), which includes the cost of initial investment and maintenance of the system, the cost of consumed fuel, and the cost of disposing of CO and NO pollutants, as well as maximizing the exergy efficiency. In the end, it is observed that the steam injection in the CC leads to the reduction of the mentioned pollutant index, and it is proposed as a suitable solution to reduce the pollution of the proposed cogeneration system.

Assessment of a new binary geothermal based methanol synthesis plant with power, hydrogen and freshwater

The development of an integrated binary geothermal energy production system for the synthesis of green methanol with electricity and freshwater is achieved in this study along with its thermodynamic analysis and assessment through the applications of energy and exergy methodologies. Further to being among the most promising solutions for the future, clean energy sources provide a wide range of energy carriers that may be utilized by communities as well as individuals. Among these energy carriers, hydrogen has attracted considerable attention as a realistic long-term carbon-free energy route. Moreover, methanol and ethanol are proposed as alternative energy carriers synthesized by clean hydrogen. In this regard, the developed system includes a double flash binary geothermal system, an organic Rankine cycle, a multi-effect desalination system, an alkaline electrolyzer, and a methanol synthesis system. In this system, an alkaline electrolyzer is utilized to perform hydrogen production, and then the produced hydrogen is employed for green (clean) methanol production. The performance-related parameters for the overall system and its subsystems are all thermodynamically evaluated with the Engineering Equation Solver software. The developed system utilizes geothermal energy as a renewable energy source and results confirm that the developed system produces a capacity of 0.019 kg/s of green methanol. The parametric studies are further performed to demonstrate the effects of various first flashing pressures on the qualities of steam, mass flow rates of high pressure turbine, and energy and exergy efficiencies. Moreover, the effects of geothermal well temperature on energy and exergy efficiencies are considered. The effects of electrolyzer power usage and general efficiency on the methanol production rate are alsoexamined. The overall energy and exergy efficiencies of the system are determined as 36.96% and 39.31%, respectively.

Experimental studies on solar multi - effect sea water desalination system

A multi - effect desalination (MED) system with a capacity of 10 m3 has been designed, fabricated, erected and experimented to convert sea water into potable water using solar energy. Steam is flashed initially in the flash chamber of the desalination plant, using hot water from a solar flat plate collector field and is fed to the first stage of the multi-effect evaporator. The average hot water temperature realised from the collector field is 75°C. In the multi-stage evaporator, sea water is sprayed parallelly to vacuum pressure to produce water vapour and simultaneously condense the water vapour flashing through the tube from the flash chamber / previous effects. The brine and condensate is carried to the last stage of the multi-effect desalination (MED) system by utilizing monometric head. It is observed that during the experimentation, the maximum temperature difference between inlet and outlet of the condenser cooling water is 13°C. The ejector is used to maintain the vacuum pressure during the operation of MED system including flash chamber. Experimental studies on the MED system is carried out to understand the performance as well as thermal behaviour of the system using exclusively solar energy.

Conventional and advanced exergy and exergoeconomic analysis of a novel multi-fueled cogeneration system with desalination

This work presents the economic, advanced thermodynamic, and exergoeconomic studies of a system for producing power and freshwater. The proposed system comprises a multi-effect desalination system, an organic Rankine cycle, a centrifuge, and process heaters by utilizing a mix of bagasse and municipal solid waste as primary fuels. The amounts of avoidable, unavoidable, endogenous, and exogenous shares of exergy destruction for the cycle’s components have been calculated by an advanced exergy method. For the integrated cycle, the electricity generation and freshwater productions are 36.6 MW and 7000 m3 per day, respectively. The costs of electricity production and water desalination are 2.6 US$/GJ and 4.6 US$/m3. To present an improved understanding of the system operation, an advanced exergy study is conducted on each involved component of the system at their operating conditions to identify the share of the avoidable irreversibilities. For the integrated system, 85% of the total exergy destruction is calculated to be unavoidable and just 15% of the estimated amount is avoidable. In this case, the opportunity to enhance the system’s operation is roughly limited. Additionally, 76% of the exergy destruction is endogenous, and the remaining belongs to exogenous exergy destruction.

Multi-objective optimization with multiple Pareto frontiers applied to a MED desalination system

This article presents the simulation results of a Multi Effect Desalination system coupled to a Mechanical Vapor Compression system. The system is optimized with the Non-dominated Sorting Genetic Algorithm II genetic algorithm by obtaining the optimal results for the desalination plant operating with 8–12 effects, with Forward Feeding and Parallel Cross Feeding. The best results are obtained for two cases: a) For a Multi Effect Desalination system with Parallel Cross Feeding operating with 12 effects, a Top Brine Temperature of 64 °C and a feed water flow rate of 293 kg/s. This configuration presents a Unit Cost of Distilled Water of 1.94 USD/m3 and 128.1 kg/s of fresh water. b) And for a Multi Effect Desalination system with Forward Feeding with 9 effects, a feed water flow rate of 380 kg/s, a Top Brine Temperature of 64 °C, which allows obtaining a Unit Cost of Distilled Water of 1.79 USD/m3. The same system but with 12 effects, a Top Brine Temperature of 72 °C, a feed water flow rate of 380 kg/s allows obtaining a higher water production of 152.3 kg/s, which shows that there is more than one optimal solution for this kind of systems, which depends on the figure to be optimized.

Pressure driven adsorption cycle integrated with thermal desalination

The canned food market is growing at an annually average rate of 3.6% due to easy access and awareness of dietary requirements, leading to a surge in water withdrawal and an estimated supply-demand gap of 40% by 2030. The conventional desalination processes are not sustainable due to high energy requirements and chemicals injection. The adsorption cycle is an emerging technology for desalination due to its temperature operation. It has many advantages over conventional desalination processes including integration synergy to improve overall performance. The conventional AD cycle processes, however, have lower performance due to inefficient packing of adsorbent in the beds and heat transfer losses to their massive heat exchangers. In this article, we propose an innovative pressure driven adsorption (PDAD) cycle to overcome conventional AD cycle limitations. In PDAD, firstly, low pressure steam is used to regenerate the adsorbent which eliminates the huge infrastructure requirement of water circulation and secondly, steam selectively extracts water vapours from pores, reducing energy consumption. We have tested the PDAD pilot and showed successful regeneration of silica gel at motive steam pressure of 2–5 bar. We also demonstrate that discharge steam from the PDAD at 65 °C can be used as a heat source for a multi effect desalination system when operating in hybrid mode to overcome its operational limitations. Our experiments show that the MED + PDAD cycle increases water production by up to 22% as compared to an earlier hybrid MEDAD cycle. The proposed system has excellent thermodynamic synergy with the combined CCGT power and desalination plant, where low-pressure bleed steam can be utilized more efficiently.

Performance analysis of an open absorption heat pump and thermal desalination system for heat and water recovery of coal-fired flue gas based on zero liquid discharge

An innovative combined system based on an open absorption heat pump and low-temperature multi-effect desalination system is proposed to provide fresh water and domestic hot water in order to achieve zero liquid discharge from coal-fired power plants and recover the waste heat of flue gas. This system takes into consideration the evaporation of desulfurization wastewater by flue gas. By using a 600 MW unit as an example, energy and exergy analysis is used to examine the impacts of flue gas humidity, temperature, mass, generator pressure, solution concentration, and boiler load on system performance. The findings showed that because coal-fired power plants produce a significant amount of dry flue gas, an increase in gas humidity has little effect on product supply. As a result, little variation in the combined system is caused by the desulfurization wastewater spray evaporation, which allows power plants to achieve zero liquid discharge with only a small loss in exergy efficiency of about 6%. The recovery of sensible heat rather than latent heat benefits from an increase in the bulk of dry flue gas. The recovery of heat and water benefits more from an increase in operating load or flue gas temperature than the open absorption heat pump system itself. The generator pressure and rich solution concentration have negligible effects on heat and water recovery. The open absorption heat pump system's increasing exergy efficiency trend and the boiler operating loads are also related. The exergy efficiency of the generator is the highest by about 75%, that of the desalination system is the lowest by about 29%, and the exergy destruction of the absorber is the highest by about 43%. The findings are likewise applicable to coal-fired power stations with various levels of electrical output.

The novel integration of biomass gasification plant to generate efficient power, and the waste recovery to generate cooling and freshwater: A demonstration of 4E analysis and multi-criteria optimization

It has long been understood that biomass energy may be utilized to transform chemical energy into electrical energy and is a renewable energy source. In this study, a unique combined cycle for generating reliable electricity from biomass chemical energy is presented and tested. In this regard, a new system is proposed based on a biomass gasifier using wood as inlet biomass and the gas turbine to utilize the synthesis gas. Also, the waste heat is recovered via a multi-effect desalination system, an absorption chiller, and a heat recovery steam generator (HRSG). The system is investigated from 4E analysis standpoints, and multi-objective optimization is conducted to seek the best solution for the proposed energy system. The results pinpoint that the compressor's pressure ratio, biomass moisture content, turbine inlet temperature (TIT), and biomass flow rate play a crucial role in the system's performance. Optimization results indicate that, at the optimal point, total exergy efficiency and pollutions are 28.32 % and 0.4797 kg / kWh, respectively.

Multi-Objective Optimization of Parallel Cross Multi-Effect Desalination Systems with Thermal Vapor Compression

Multi-Objective Optimization of Parallel Cross Multi-Effect Desalination Systems with Thermal Vapor Compression

Technoeconomic Assessment of LNG-Fueled Solid Oxide Fuel Cells in Small Island Systems: The Patmos Island Case Study

Liquefied natural gas (LNG) is regarded as the cleanest among fossil fuels due to its lower environmental impact. In power plants, it emits 50–60% less carbon dioxide into the atmosphere compared to regular oil or coal-fired plants. As the demand for a lower environmental footprint is increasing, fuel cells powered by LNG are starting to appear as a promising technology, especially suitable for off-grid applications, since they can supply both electricity and heating. This article presents a techno-economic assessment for an integrated system consisting of a solid oxide fuel cell (SOFC) stack and a micro gas turbine (MGT) fueled by LNG, that feeds the waste heat to a multi-effect desalination system (MED) on the Greek island of Patmos. The partial or total replacement of the diesel engines on the non-interconnected island of Patmos with SOFC systems is investigated. The optimal system implementation is analyzed through a multi-stage approach that includes dynamic computational analysis, techno-economic evaluation of different scenarios using financial analysis and literature data, and analysis of the environmental and social impact on the island. Specific economic indicators such as payback, net present value, and internal rate of return were used to verify the economic feasibility of this system. Early results indicate that the most sensitive and important design parameter in the system is fuel cell capital cost, which has a significant effect on the balance between investment cost and repayment years. The results of this study also indicate that energy production with an LNG-fueled SOFC system is a promising solution for non-interconnected Greek islands, as an intermediate carrier prior to the long-term target of a CO₂-free economy.

Enviro-exergo-economic analysis and optimization of a nanofiltration-multi effect desalination, power generation and cooling in an innovative trigeneration plant

In this work, an innovative trigeneration system integrating the combined nano filtration - multi effect desalination system to absorption chiller for cooling, steam Rankine cycle for power output, parabolic trough collector, and auxiliary natural gas-fired heater for heat input. Energy, exergoeconomic, and environmental models are developed for the proposed plant. Comparison between systems with/without nanofiltration is conducted. Then, a parametric study is exhibited and discussed. Finally, multi-objective optimization process is carried out using genetic algorithm to achieve minimum investment cost rate and maximum exergetic efficiency. Results showed that the nanofiltration unit addition decreases the overall plant exergy destruction, investment cost rate and annual fuel consumption by 12.11%, 6.88% and 12.1% respectively. Moreover, the annual CO 2 emissions can be enhanced by about 9% with the heating steam temperature of the desalination unit. On the other hand, parametric study revealed that increasing the absorption generator temperature and the desalination unit number of evaporators is recommended from the energetic exegetic, and exergoeconomic points of view. While the plant investment cost per hour is negatively affected by number of evaporators increase. The annual CO 2 emissions avoided can be enhanced by about 9% with the NF-MED heating steam temperature increase. Optimization process showed that the optimal operation conditions can decrease the total product cost rates by 2.94% and increase the exergy efficiency by 5.26% compared to the base system.

Experimental and Numerical Study of Hydrodynamic and Heat Transfer Characteristics of Falling Film Over Metal Foam Layered Horizontal Tube

AbstractA novel nonintrusive technique based on an air-coupled ultrasonic transducer was used to study the hydrodynamic behavior of falling film over metal foam layered horizontal tube. Copper foam having a porosity of 90.5%, brazed over a copper tube of 25.4 mm diameter was used in this study. Falling film thickness distribution in the circumferential direction and the dynamic characteristics of falling film were studied in the falling film Reynolds number range of 356–715, and at a tube spacing of 5 mm and 15 mm. The falling film characteristics over metal foam layered horizontal tubes were compared with that over a plain horizontal tube surface. Heat transfer studies of falling film over metal foam layered tube were studied in an evaporator of a multi-effect desalination system by experiment. It was observed that the falling film heat transfer coefficient was enhanced 2.7 times by the application of metal foam over the plain horizontal tube. The measurements obtained from hydrodynamic and heat transfer studies were compared with the predictions made by a computational model and were found to be in good agreement. Metal foam properties required for the computational model were obtained using a microcomputed tomography-based study.

A new standalone single effect thermal vapor compression desalination plant with nano-filtration pretreatment

Thermal vapor compression is one of the most efficient techniques used in both small and medium scale desalination systems. However, the system works under vacuum pressure which is complex in design that uses expensive materials. Thus, a new system design is proposed to allow operation at atmospheric pressure to bypass scaling issues involving nano-filtration technology. The nanofiltration membrane is used as a pre-treatment, to rise the top brine temperature to almost 100 °C and operate the plant at atmospheric pressure. The proposed plant uses solar energy as the main source of thermal/electrical energy. To assess the performance of the new system, energy, exergetic, economic and environmental analysis are carried out for 500 m3/day standalone solar-nanofiltration-thermal vapor compression desalination plant (Solar-NF-TVC). In addition, the proposed system is tested under different operating conditions such as feed water temperature, compression ratio, salt rejection, recovery ratio and motive steam pressure. Results indicate that the plant exergetic efficiency is up to 10%, which is higher than the multi-effect desalination system, reverse osmosis, multi-effect evaporation mechanical vapor compression and multi-effect desalination thermal vapor compression. The compression ratio is found to be the most effective control variable that affects the plant performance ratio, and the feed water temperature has the most significant effect on exergetic efficiency. The saved amount of CO2 is equal 13661.2 ton/yr. Finally, the plant unit water price is found to be equal to 0.89 $/m3. Overall, the proposed cost-effective desalination plant is more suitable for remote areas due to its manufacturing from local available materials.

Thermo-economic comparison of two models of combined transcritical CO2 refrigeration and multi-effect desalination system

Combined refrigeration and boosted multi-effect desalination systems (B-MED) are very useful and energy efficient for water and cold cogeneration. This study aims to improve such an integrated system. An original system of a combined transcritical CO2 refrigeration and boosted multi-effect desalination is studied and analyzed at 85 ℃ inlet heat source temperature; the desalination cycle in the original system (1B-MED) consists of six effects and one booster module. The original model is modified by adding another booster module; the desalination cycle in the modified system (2B-MED) consists of six effects and two booster modules at 85 ℃. By increasing the inlet heat source temperature, the number of effects increases. A Thermo-economic analysis is obtained to analyze and assess the two systems at different inlet heat source temperatures 85–110 ℃ with a various number of effects 6–11 effects. The results show that the modified system with two booster modules is thermo-economically more efficient than the original one with one booster module since the freshwater production rate increases by around 65, 74, 82, 87, 97 and 104 m3 per day at 85, 90, 95, 100, 105, and 110 ℃, respectively, with an increasing rate of 22 % – 23 %. Moreover, the unit product cost UPC of the modified system decreases to reach its lowest value at 105, 110 ℃, with a decreasing rate of more than 25 % compared to the original model with one booster module.

Techno-economic, environmental and emergy analysis and optimization of integrated solar parabolic trough collector and multi effect distillation systems with a combined cycle power plant

In this investigation, the improvement of the combined power plant that is located in Qom province was studied based on using solar energy and multi-effect desalination system. In this regard, energy, exergy, exergoeconomic, exergoenvironmental, emergoeconomic, emergoenvironmental as (6 E) analysis has been performed. Also, multi -objective genetic algorithm (MOGA) was applied to optimization of the propose cycle in view of 6 E analysis. Due to the high complexity of the optimization problem and reduce the computation time, the combination of genetic programing and artificial neural network has been employed to generate exact correlation for objective functions. The initial results demonstrated that adding the solar-based-thermal system caused an improvement of about 1.91% in the exergetic efficiency of the base plant. Moreover, by simultaneous integration of solar unit and desalination system in the base plant, the new-designed plant could generate 33 kg/s freshwater. It was determined from optimization results that the exergetic efficiency of the proposed plant increased by 3.22%. Furthermore, after optimization and at the optimum operating condition, power generation costs, power generation's environmental impacts, freshwater generation's costs, freshwater production's environmental impacts, and the emergy of the proposed system decreased about 6.27%, 24.51%, 36.51%, 26.13%, and 1.87%, respectively.