The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Hassan E S Fath - One of the best experts on this subject based on the ideXlab platform.
-
Exergy and thermo-economic analysis of solar thermal cycles powered Multi-Stage Flash desalination process
Desalination and Water Treatment, 2013Co-Authors: Mohamed A. Sharaf Eldean, Hassan E S FathAbstract:AbstractSolar thermal power cycles assisted Multi-Stage Flash brine recycle (MSF-BR) distillation process are thermo-economically analyzed and evaluated. In this work, the analyses are compared according to three different configurations via two techniques of solar thermal power cycles. The first technique is considered for only desalination process; however, the second is considered for desalination and electric power generation via organic Rankine cycle. Solar parabolic trough concentrator (PTC) field is considered to dominate sufficient thermal power for MSF plant. Water steam working fluid is used for a direct vapor generation (DVG); however, Therminol-VP1 working substance is used for an indirect vapor generation (IDVG) through the PTC field. Moreover, the optimized configuration from the first technique is compared with the power generation and desalination (the second technique). The comparisons are proceeding for the MSF-BR desalination plant with total productivity in the range of 5,000m3/d which...
-
analysis of a new design of a multi stage Flash mechanical vapor compression desalination process
Desalination, 2007Co-Authors: A A Mabrouk, Ahmed Safwat Nafey, Hassan E S FathAbstract:In this work, a new design of a Multi Stage Flash-M echanical Vapor Compression (MSF-MVC) desalination process is investigated. The analysis of the proposed MSFMVC system is performed based on the energy, exergy and thermoeconomic methodologies. The considered system is investigate d under different operating conditions using a developed Visual Design and Simulation (VDS) software. To examine the performance of the proposed process, a comparison with the conventional MSF desalination process is performed. Thermoeconomic results show that, the best operatin g suction pressure is 8 kPa and the best top brine temperature is 110 °C. The effect of the stages number of the heat recovery section is investigated and the results sh ow that the low unit product cost is obtained at 20 stages. The effect of the temperatur e difference across the vent chamber is conducted and the results show that the lower un it product cost is 6 °C. Thermoeconomic analysis shows that the last stage ( vent chamber) has the highest value of the sum of capital and operation & mainten ance cost in addition to the exergy destruction cost. Also the last stage has higher re lative cost difference and lower exergetic efficiency. This in turn shows that a red uction in the exergy destruction within the vent chamber will reduce the unit produc t cost. The performance ratio of the proposed MSF-MVC system is 2.4 times the performance ratio of the conventional MSF process. The heat transfer area of the MSF-MVC system is 57 % higher than that of the conventional MSF. The exergetic efficiency o f the MSF-MVC system is 67 % higher than that of the MSF. The thermoeconomic results show that the unit product cost of MSF-MVC, under the specified conditions, is calculated by 2.0 $/m 3 and this value is 25 % less than that of the conventional MS F process.
-
Analysis of a new design of a Multi-Stage Flash–mechanical vapor compression desalination process
Desalination, 2007Co-Authors: A A Mabrouk, Ahmed Safwat Nafey, Hassan E S FathAbstract:In this work, a new design of a Multi Stage Flash-M echanical Vapor Compression (MSF-MVC) desalination process is investigated. The analysis of the proposed MSFMVC system is performed based on the energy, exergy and thermoeconomic methodologies. The considered system is investigate d under different operating conditions using a developed Visual Design and Simulation (VDS) software. To examine the performance of the proposed process, a comparison with the conventional MSF desalination process is performed. Thermoeconomic results show that, the best operatin g suction pressure is 8 kPa and the best top brine temperature is 110 °C. The effect of the stages number of the heat recovery section is investigated and the results sh ow that the low unit product cost is obtained at 20 stages. The effect of the temperatur e difference across the vent chamber is conducted and the results show that the lower un it product cost is 6 °C. Thermoeconomic analysis shows that the last stage ( vent chamber) has the highest value of the sum of capital and operation & mainten ance cost in addition to the exergy destruction cost. Also the last stage has higher re lative cost difference and lower exergetic efficiency. This in turn shows that a red uction in the exergy destruction within the vent chamber will reduce the unit produc t cost. The performance ratio of the proposed MSF-MVC system is 2.4 times the performance ratio of the conventional MSF process. The heat transfer area of the MSF-MVC system is 57 % higher than that of the conventional MSF. The exergetic efficiency o f the MSF-MVC system is 67 % higher than that of the MSF. The thermoeconomic results show that the unit product cost of MSF-MVC, under the specified conditions, is calculated by 2.0 $/m 3 and this value is 25 % less than that of the conventional MS F process.
-
THERMOECONOMIC ANALYSIS OF MULTI STAGE Flash- THERMAL VAPOR COMPRESSSION (MSF-TVC) DESALINATION PROCESS
2006Co-Authors: Ahmed Safwat Nafey, Hassan E S Fath, A A MabroukAbstract:This work presents the design and thermoeconomic analysis of a proposed multi stage Flash-thermal vapor compression MSF-TVC system. The proposed MSF-TVC system is analyzed and investigated under different operat ing conditions by using the thermoeconomic methodology. The optimum operating conditions of the proposed system is achieved at 6 kPa entrained pressure, top brine temperature110oC, splitter ratio equal to 0.28. Under these conditions the uni t product cost is calculated by 2.15 $/m 3 . The comparison between the proposed MSF-TVC system and the conventional MSF system showed that the gain ratio of the MSF-TVC system is 96% higher than that of the conventional MSF brine circ ulation plant. The heat transfer area of the MSF-TVC is 52 % higher than the conventional MSF. The exergetic efficiency of the MSF-TVC system is 46 % higher than that of the MSF system. The unit product cost of the MSF-TVC system is 19 % lower than that of the conventional brine circulation multi stage Flash (MSF-BR) system.
-
Thermo-economic investigation of multi effect evaporation (MEE) and hybrid multi effect evaporation—multi stage Flash (MEE-MSF) systems
Desalination, 2006Co-Authors: Ahmed Safwat Nafey, Hassan E S Fath, A A MabroukAbstract:In this investigation, a number of comparisons for Multi Effect Evaporation (MEE) as well as hybrid Multi Effect Evaporation ‐ Multi Stage Flash (MEE-MSF) systems have been performed using the exergy and thermoeconomics analysis. The comparison is performed based on the same platform and working under the same operating conditions. Thermoeconomics analysis is applied to account for both energy and cost simultaneously. The best of the MEE and MEE-MSF studied configurations, from the economical point of view, is obtained. The numerical results reveal that the unit product cost of forward feed FF-MEE configuration is 25 % less than that of the parallel/cross P/C-MEE configuration. A comparison between two hybrid configurations of MEE_MSF systems showed that the unit product cost of the once through (MEE-MSF-OT) is 5 % less than the mixing brine (MEE-MSF-M) system. Thermoeconomics results of the comparison between the forward feed FF-MEE, and the combined MEE-MSF-OT showed that the combined system has a unit product cost of 7 % less than that of the FF-MEE under the same operating conditions.
Hisham El-dessouky - One of the best experts on this subject based on the ideXlab platform.
-
Multi-Stage Flash Desalination Process: A Thermal Analysis
Developments in Chemical Engineering and Mineral Processing, 2008Co-Authors: Hisham El-dessouky, Habib I. Shaban, Hamida Al-ramadanAbstract:Multi-Stage Flash (MSF) desalination processes play a vital role in the provision of fresh water in many areas of the World, particularly in the Arab Gulf countries. This paper describes a steady-state mathematical model developed to analyze the MSF water desalination process. Relations between parameters controlling the product water cost (e.g. thermal performance ratio, specific heat transfer surface area, and specific flow rate of cooling water and recirculated brine) to other operating and design variables are established. These relations can be used to design new plants or to analyze existing units. The model assumes the practical case of constant heat-transfer surface area per stage in each section. It considered the variation of water physical properties with temperature and salt concentration, the effect of fouling factors, and the presence of non-condensable gases on the overall heat-transfer coefficients, and variations in stage Flash down and thermodynamic loss from stage to stage. The model also takes into consideration the heat transfer losses from the stages to the surrounding and through rejection of the noncondensable gases. The results obtained from the developed model are compared with data from six different MSF plants, and good agreement is obtained.
-
Fundamentals of Salt Water Desalination - Chapter 6 – Multi-Stage Flash Desalination
Fundamentals of Salt Water Desalination, 2002Co-Authors: Hisham El-dessouky, Hisham EttouneyAbstract:This chapter analyzes and evaluates the performance of the multistage Flash desalination (MSF) system. This is made through a discussion of the process developments of MSF; standard features of the brine circulation MSF process; modeling and analysis of the single stage Flashing system, the once through multistage system, and the brine circulation multistage system; and features and performance of novel configurations, which include MSF with brine mixing and MSF with thermal vapor compression. The MSF process is an innovative concept, where vapor formation takes place within the liquid bulk instead of the surface of hot tubes. The chapter also presents a novel system for the Multi-Stage Flash desalination. The system is based on the conventional MSF configuration. It includes two of its basic elements; the brine heater and the heat recovery section. The cooling water stream, typical of the MSF system, is also eliminated. The new system adopts a direct brine recycle stream from the brine stream leaving the last Flashing stage. This stream is mixed with the intake seawater stream in an insulated and vented tank. Accordingly, the temperature of the feed stream is adjusted to meet summer and winter operating conditions.
-
Multi-Stage Flash desalination: present and future outlook
Chemical Engineering Journal, 1999Co-Authors: Hisham El-dessouky, Hisham Ettouney, Yousef Al-roumiAbstract:Abstract Multi-Stage Flash desalination (MSF) is currently the workhorse of the desalination industry with a market share close to 60% of the total world production capacity. As the turning point of the new millennium nears, the process faces many challenges dictated by industrial demands and public needs. The conservative nature of the desalination owner, as well as the strategic characteristics of the product, makes the MSF process favored over other competitive thermal desalination methods. In addition, the process has several merits, which include a large production capacity, proven reliability and well-developed construction and operation experience. This study offers an overview of the present and future developments in the MSF process, which aims to reduce the production cost. Special attention is given to the process fundamentals, which are the key elements for any serious and physically sound development of the MSF process. Also, a summary of the novel (MSF-M) configuration is given, which has recently been proposed by the authors. The process is based on the modification of operational MSF plants as well as the concept of once-through MSF. The modification involves removal of the heat rejection section and the addition of a mixing tank for the feed stream and the unevaporated brine recycle. This eliminates the amount of energy rejected in the cooling seawater stream and reduces the amount of energy rejected in the brine blowdown stream. Analysis of the MSF-M process shows an increase in the thermal performance ratio by a factor of 2–3 over conventional MSF.
-
Process synthesis : the Multi-Stage Flash desalination system
Desalination, 1998Co-Authors: Hisham El-dessouky, Imad M. Alatiqi, Hisham EttouneyAbstract:The process flow diagram for the Multi-Stage Flash (MSF) desalination process is quiet complex, where it includes several stages for brine Flashing, preheaters for feed seawater, two sections for heat recovery and rejection, cooling water stream, and brine recycle stream. The process fundamentals are analyzed in order to have a better understanding of the functions and relations for various elements in the process. The analysis is based on performance characteristics for a number of simplified configurations. These characteristics include the amount of product water per unit mass of heating steam, the specific heat transfer area, the specific flow rates of the cooling and feed seawater, and the salinity, temperature, and specific flow rate of brine recycle and blow down. These characteristics are affected by limitations imposed on the number of stages, the stage temperature drop, and terminal temperature difference in the preheaters. The configurations considered in the analysis include a single-stage Flashing unit, a once-through Multi-Stage Flashing system, and configurations with brine recycle. The brine recycle systems include a simple mixer for feed seawater and recycle brine as well as one, two, and three Flashing stages in the heat rejection section. A summary of the results show that a single-stage Flashing unit has a thermal performance ratio less than one and the once-through system has a very large specific flow rate for the feed seawater. In addition, use of the simple brine recycle mixer results in a high temperature of the rejected brine. The single-stage heat rejection cannot be applied because pinching of the temperature profiles of the feed seawater and condensing vapor. The two-stage heat rejection section is not economical because of the small temperature driving force, which results in large heat transfer areas. This analysis leads to the conventional MSF system, which includes three stages or more in the heat rejection section.
-
A fixed point iterative algorithm for solving equations modeling the Multi-Stage Flash desalination process
Computer Methods in Applied Mechanics and Engineering, 1997Co-Authors: Hisham El-dessouky, S. BingulacAbstract:Abstract The paper presents an algorithm for solving the equations simulating the steady state behavior of the Multi Stage Flash (MSF) desalination process. The model can be used either for design of new plants or analysis and optimization of existing units. The set of equations relating the large number of design and operating variables for any stage ( i th stage) in MSF plant are decomposed into three subsets. The first subset contains equations describing processes in the tubes of the preheater inside the Flashing chamber. The second subset deals with the processes inside the Flashing chamber. These two subsets of equations are subsequently solved iteratively involving only a single variable for each subset. These variables are: (i) Saturation temperature T vi of the Flashed-off vapor and (ii) Temperature of the unevaporated brine flowing from the chamber. The third subset of equations considered the existing interactions between the first two subsets. This subset defines the mass of vapor formed by Flashing D i in the i th stage. All equations in the above-mentioned three subsets are solved by a reliable and efficient one-dimensional fixed-point iteration. The main advantages of this method are less sensitivity to initial guesses, requires a small number of iterations to obtain the required solution, and there is no need for calculating derivatives. The algorithm is implemented using the Computer-Aided Design (CAD) interactive package L-A-S (Linear Algebra and Systems). Detailed results are presented to show the dependence of the important factors controlling the fresh water cost, which are plant performance ratio, specific heat transfer area, specific brine flow rate, and specific cooling water flow rate, on the most significant two design variables, namely the total number of stages and the top brine temperature. The predicted data from the model are compared with published data of a typical MSF plant in operation at Kuwait. The agreement is found to be very good.
M.a. Darwish - One of the best experts on this subject based on the ideXlab platform.
-
Energy consumption by Multi-Stage Flash and reverse osmosis desalters
Applied Thermal Engineering, 2000Co-Authors: M.a. Darwish, N.m. Al-najemAbstract:Abstract Kuwait and most of the Gulf countries, depend mainly on desalted water from the sea for satisfying their fresh water needs. These countries are using the Multi-Stage Flash (MSF) desalting system, as the ‘work horse’ for their water production. This system is less efficient in energy consumption as compared to the reverse osmosis (RO) system. Moreover, large units based on the MSF system have to be combined with steam or gas turbines power plants for better utilization of steam supplied to the MSF units at moderately low temperature and pressure (as compared to steam produced by large steam generators). The value and the cost of the thermal energy supplied to the MSF desalting system depends on the method of supplying this energy. This steam can be supplied directly from a fuel operated boiler or heat recovery steam generator associated with a gas turbine. It can also be supplied from the exhaust of a steam back pressure turbine or bled from condensed extraction steam turbine at a pressure suitable for the desalting process. Any energy comparison should be based on simple criteria, either how much fuel energy is consumed to produce this energy or how much mechanical energy is needed per unit product. The energy consumed in the light of the practice used in most Gulf countries are discussed here. In this study, reference desalting and power plants are used for comparison purposes. This study shows that shifting from MSF desalting system to the RO system can save up to 66% of the fuel energy used to desalt seawater.
-
Developments in the Multi-Stage Flash desalting system
Desalination, 1995Co-Authors: M.a. Darwish, M.m. El-refaee, M. Abdel-jawadAbstract:New developments in the design of the Multi-Stage Flash (MSF) desalting system are outlined. The history of changing the flow sheet is given. The main design parameters as well as specifications of the equipment used are outlined.
-
Second-law analysis of recirculating Multi-Stage Flash desalting system
Desalination, 1993Co-Authors: M.a. Darwish, N.m. Al-najem, M.s.h. Al-ahmadAbstract:Abstract A comprehensive study is conducted to analyze a recirculating Multi-Stage Flash desalting plant based on the second law of thermodynamics. Although the first law of thermodynamics indicates the overall performance of the desalting plants, it does not show the actual losses in each process of the plant. In this work the energy (i.e., availability) losses due to the irreversibilities in different processes in the plant are evaluated. The study shows that the major exergy losses occur, respectively, in the vapor condensation processes, the vapor Flashing process, and the feed heating process in the brine heater. The other losses due to heat transfer through walls, pressure drop through demisters, and friction flow in pipes are negligible.
-
Thermal analysis of Multi-Stage Flash desalting systems
Desalination, 1991Co-Authors: M.a. DarwishAbstract:Abstract In this paper a thermal analysis is made of the MSF desalting system in an attempt to arrive at a better quantitative assessment of design and operation parameters on MSF performance.
A A Mabrouk - One of the best experts on this subject based on the ideXlab platform.
-
analysis of a new design of a multi stage Flash mechanical vapor compression desalination process
Desalination, 2007Co-Authors: A A Mabrouk, Ahmed Safwat Nafey, Hassan E S FathAbstract:In this work, a new design of a Multi Stage Flash-M echanical Vapor Compression (MSF-MVC) desalination process is investigated. The analysis of the proposed MSFMVC system is performed based on the energy, exergy and thermoeconomic methodologies. The considered system is investigate d under different operating conditions using a developed Visual Design and Simulation (VDS) software. To examine the performance of the proposed process, a comparison with the conventional MSF desalination process is performed. Thermoeconomic results show that, the best operatin g suction pressure is 8 kPa and the best top brine temperature is 110 °C. The effect of the stages number of the heat recovery section is investigated and the results sh ow that the low unit product cost is obtained at 20 stages. The effect of the temperatur e difference across the vent chamber is conducted and the results show that the lower un it product cost is 6 °C. Thermoeconomic analysis shows that the last stage ( vent chamber) has the highest value of the sum of capital and operation & mainten ance cost in addition to the exergy destruction cost. Also the last stage has higher re lative cost difference and lower exergetic efficiency. This in turn shows that a red uction in the exergy destruction within the vent chamber will reduce the unit produc t cost. The performance ratio of the proposed MSF-MVC system is 2.4 times the performance ratio of the conventional MSF process. The heat transfer area of the MSF-MVC system is 57 % higher than that of the conventional MSF. The exergetic efficiency o f the MSF-MVC system is 67 % higher than that of the MSF. The thermoeconomic results show that the unit product cost of MSF-MVC, under the specified conditions, is calculated by 2.0 $/m 3 and this value is 25 % less than that of the conventional MS F process.
-
Analysis of a new design of a Multi-Stage Flash–mechanical vapor compression desalination process
Desalination, 2007Co-Authors: A A Mabrouk, Ahmed Safwat Nafey, Hassan E S FathAbstract:In this work, a new design of a Multi Stage Flash-M echanical Vapor Compression (MSF-MVC) desalination process is investigated. The analysis of the proposed MSFMVC system is performed based on the energy, exergy and thermoeconomic methodologies. The considered system is investigate d under different operating conditions using a developed Visual Design and Simulation (VDS) software. To examine the performance of the proposed process, a comparison with the conventional MSF desalination process is performed. Thermoeconomic results show that, the best operatin g suction pressure is 8 kPa and the best top brine temperature is 110 °C. The effect of the stages number of the heat recovery section is investigated and the results sh ow that the low unit product cost is obtained at 20 stages. The effect of the temperatur e difference across the vent chamber is conducted and the results show that the lower un it product cost is 6 °C. Thermoeconomic analysis shows that the last stage ( vent chamber) has the highest value of the sum of capital and operation & mainten ance cost in addition to the exergy destruction cost. Also the last stage has higher re lative cost difference and lower exergetic efficiency. This in turn shows that a red uction in the exergy destruction within the vent chamber will reduce the unit produc t cost. The performance ratio of the proposed MSF-MVC system is 2.4 times the performance ratio of the conventional MSF process. The heat transfer area of the MSF-MVC system is 57 % higher than that of the conventional MSF. The exergetic efficiency o f the MSF-MVC system is 67 % higher than that of the MSF. The thermoeconomic results show that the unit product cost of MSF-MVC, under the specified conditions, is calculated by 2.0 $/m 3 and this value is 25 % less than that of the conventional MS F process.
-
THERMOECONOMIC ANALYSIS OF MULTI STAGE Flash- THERMAL VAPOR COMPRESSSION (MSF-TVC) DESALINATION PROCESS
2006Co-Authors: Ahmed Safwat Nafey, Hassan E S Fath, A A MabroukAbstract:This work presents the design and thermoeconomic analysis of a proposed multi stage Flash-thermal vapor compression MSF-TVC system. The proposed MSF-TVC system is analyzed and investigated under different operat ing conditions by using the thermoeconomic methodology. The optimum operating conditions of the proposed system is achieved at 6 kPa entrained pressure, top brine temperature110oC, splitter ratio equal to 0.28. Under these conditions the uni t product cost is calculated by 2.15 $/m 3 . The comparison between the proposed MSF-TVC system and the conventional MSF system showed that the gain ratio of the MSF-TVC system is 96% higher than that of the conventional MSF brine circ ulation plant. The heat transfer area of the MSF-TVC is 52 % higher than the conventional MSF. The exergetic efficiency of the MSF-TVC system is 46 % higher than that of the MSF system. The unit product cost of the MSF-TVC system is 19 % lower than that of the conventional brine circulation multi stage Flash (MSF-BR) system.
-
Thermo-economic investigation of multi effect evaporation (MEE) and hybrid multi effect evaporation—multi stage Flash (MEE-MSF) systems
Desalination, 2006Co-Authors: Ahmed Safwat Nafey, Hassan E S Fath, A A MabroukAbstract:In this investigation, a number of comparisons for Multi Effect Evaporation (MEE) as well as hybrid Multi Effect Evaporation ‐ Multi Stage Flash (MEE-MSF) systems have been performed using the exergy and thermoeconomics analysis. The comparison is performed based on the same platform and working under the same operating conditions. Thermoeconomics analysis is applied to account for both energy and cost simultaneously. The best of the MEE and MEE-MSF studied configurations, from the economical point of view, is obtained. The numerical results reveal that the unit product cost of forward feed FF-MEE configuration is 25 % less than that of the parallel/cross P/C-MEE configuration. A comparison between two hybrid configurations of MEE_MSF systems showed that the unit product cost of the once through (MEE-MSF-OT) is 5 % less than the mixing brine (MEE-MSF-M) system. Thermoeconomics results of the comparison between the forward feed FF-MEE, and the combined MEE-MSF-OT showed that the combined system has a unit product cost of 7 % less than that of the FF-MEE under the same operating conditions.
Ahmed Safwat Nafey - One of the best experts on this subject based on the ideXlab platform.
-
analysis of a new design of a multi stage Flash mechanical vapor compression desalination process
Desalination, 2007Co-Authors: A A Mabrouk, Ahmed Safwat Nafey, Hassan E S FathAbstract:In this work, a new design of a Multi Stage Flash-M echanical Vapor Compression (MSF-MVC) desalination process is investigated. The analysis of the proposed MSFMVC system is performed based on the energy, exergy and thermoeconomic methodologies. The considered system is investigate d under different operating conditions using a developed Visual Design and Simulation (VDS) software. To examine the performance of the proposed process, a comparison with the conventional MSF desalination process is performed. Thermoeconomic results show that, the best operatin g suction pressure is 8 kPa and the best top brine temperature is 110 °C. The effect of the stages number of the heat recovery section is investigated and the results sh ow that the low unit product cost is obtained at 20 stages. The effect of the temperatur e difference across the vent chamber is conducted and the results show that the lower un it product cost is 6 °C. Thermoeconomic analysis shows that the last stage ( vent chamber) has the highest value of the sum of capital and operation & mainten ance cost in addition to the exergy destruction cost. Also the last stage has higher re lative cost difference and lower exergetic efficiency. This in turn shows that a red uction in the exergy destruction within the vent chamber will reduce the unit produc t cost. The performance ratio of the proposed MSF-MVC system is 2.4 times the performance ratio of the conventional MSF process. The heat transfer area of the MSF-MVC system is 57 % higher than that of the conventional MSF. The exergetic efficiency o f the MSF-MVC system is 67 % higher than that of the MSF. The thermoeconomic results show that the unit product cost of MSF-MVC, under the specified conditions, is calculated by 2.0 $/m 3 and this value is 25 % less than that of the conventional MS F process.
-
Analysis of a new design of a Multi-Stage Flash–mechanical vapor compression desalination process
Desalination, 2007Co-Authors: A A Mabrouk, Ahmed Safwat Nafey, Hassan E S FathAbstract:In this work, a new design of a Multi Stage Flash-M echanical Vapor Compression (MSF-MVC) desalination process is investigated. The analysis of the proposed MSFMVC system is performed based on the energy, exergy and thermoeconomic methodologies. The considered system is investigate d under different operating conditions using a developed Visual Design and Simulation (VDS) software. To examine the performance of the proposed process, a comparison with the conventional MSF desalination process is performed. Thermoeconomic results show that, the best operatin g suction pressure is 8 kPa and the best top brine temperature is 110 °C. The effect of the stages number of the heat recovery section is investigated and the results sh ow that the low unit product cost is obtained at 20 stages. The effect of the temperatur e difference across the vent chamber is conducted and the results show that the lower un it product cost is 6 °C. Thermoeconomic analysis shows that the last stage ( vent chamber) has the highest value of the sum of capital and operation & mainten ance cost in addition to the exergy destruction cost. Also the last stage has higher re lative cost difference and lower exergetic efficiency. This in turn shows that a red uction in the exergy destruction within the vent chamber will reduce the unit produc t cost. The performance ratio of the proposed MSF-MVC system is 2.4 times the performance ratio of the conventional MSF process. The heat transfer area of the MSF-MVC system is 57 % higher than that of the conventional MSF. The exergetic efficiency o f the MSF-MVC system is 67 % higher than that of the MSF. The thermoeconomic results show that the unit product cost of MSF-MVC, under the specified conditions, is calculated by 2.0 $/m 3 and this value is 25 % less than that of the conventional MS F process.
-
THERMOECONOMIC ANALYSIS OF MULTI STAGE Flash- THERMAL VAPOR COMPRESSSION (MSF-TVC) DESALINATION PROCESS
2006Co-Authors: Ahmed Safwat Nafey, Hassan E S Fath, A A MabroukAbstract:This work presents the design and thermoeconomic analysis of a proposed multi stage Flash-thermal vapor compression MSF-TVC system. The proposed MSF-TVC system is analyzed and investigated under different operat ing conditions by using the thermoeconomic methodology. The optimum operating conditions of the proposed system is achieved at 6 kPa entrained pressure, top brine temperature110oC, splitter ratio equal to 0.28. Under these conditions the uni t product cost is calculated by 2.15 $/m 3 . The comparison between the proposed MSF-TVC system and the conventional MSF system showed that the gain ratio of the MSF-TVC system is 96% higher than that of the conventional MSF brine circ ulation plant. The heat transfer area of the MSF-TVC is 52 % higher than the conventional MSF. The exergetic efficiency of the MSF-TVC system is 46 % higher than that of the MSF system. The unit product cost of the MSF-TVC system is 19 % lower than that of the conventional brine circulation multi stage Flash (MSF-BR) system.
-
Thermo-economic investigation of multi effect evaporation (MEE) and hybrid multi effect evaporation—multi stage Flash (MEE-MSF) systems
Desalination, 2006Co-Authors: Ahmed Safwat Nafey, Hassan E S Fath, A A MabroukAbstract:In this investigation, a number of comparisons for Multi Effect Evaporation (MEE) as well as hybrid Multi Effect Evaporation ‐ Multi Stage Flash (MEE-MSF) systems have been performed using the exergy and thermoeconomics analysis. The comparison is performed based on the same platform and working under the same operating conditions. Thermoeconomics analysis is applied to account for both energy and cost simultaneously. The best of the MEE and MEE-MSF studied configurations, from the economical point of view, is obtained. The numerical results reveal that the unit product cost of forward feed FF-MEE configuration is 25 % less than that of the parallel/cross P/C-MEE configuration. A comparison between two hybrid configurations of MEE_MSF systems showed that the unit product cost of the once through (MEE-MSF-OT) is 5 % less than the mixing brine (MEE-MSF-M) system. Thermoeconomics results of the comparison between the forward feed FF-MEE, and the combined MEE-MSF-OT showed that the combined system has a unit product cost of 7 % less than that of the FF-MEE under the same operating conditions.