The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform

Adel K. El-fiqi - One of the best experts on this subject based on the ideXlab platform.

  • Thermal performance of seawater desalination systems
    Desalination, 2003
    Co-Authors: Narmine H. Aly, Adel K. El-fiqi
    Abstract:

    This work describes a steady-state mathematical model developed to analyze both the multi-stage and multi-effect desalination systems. For MSF the model accounts for the geometry of the stages, the mechanism of heat transfer, and the variation of the physical properties of seawater with temperature and salinity. In addition, the model takes into consideration the role of Fouling and its effect on the plant performance ratio. Relationships among the parameters controlling the product water cost to other operating and design parameters are presented. These parameters include plant performance ratio, specific flow rate of recirculating brine, top brine temperature, and specific heat transfer area. These relationships are used for studying a typical operating plant. The results obtained by the model are compared with data from the Sidi-Krir plant in west Alexandria, which contains 17 recovery and three rejection stages. There is good agreement between the calculated results and the plant data. The model results are also used to study the different operating conditions such as part load; for example, the effect of decreasing the recirculated flow rate and/or the top brine temperature on the unit performance ratio. In addition, the effect of decreasing the seawater temperature below the design value shows an increase in the unit production rate, while increasing the Fouling Factor reduces the plant production rate. For MED, the effect of the process variables on the performance of a "forward type" multi-effect boiling falling film is carried out. This includes the effect of number of effects and top brine temperature on performance ratio. In addition, the influence of these Factors on the specific heat transfer area and the effect of seawater inlet temperature on the performance ratio are investigated. The effect of the top brine temperature and the temperature difference per effect on the performance ratio, the specific heat transfer area, and the cooling brine flow rate are also investigated. The study results indicate that the performance ratio is completely dependent on the number of effects and slightly dependent on the top brine temperature.

Sami I. Attia - One of the best experts on this subject based on the ideXlab platform.

  • The combined effect of changes in the condenser cooling seawater temperature, Fouling and salinity on the thermal performance of a pressurised water reactor nuclear power plant
    International Journal of Nuclear Energy Science and Technology, 2015
    Co-Authors: Said M.a. Ibrahim, Sami I. Attia
    Abstract:

    This study presents the effect of temperature, Fouling Factor and salinity of the condenser cooling seawater and adverse effect on the thermal performance of a nuclear power plant. These are the most important Factors affecting the condenser performance. The study is carried out on a pressurised water reactor nuclear power plant. The results showed that a loss in the plant output power and thermal efficiency of up to 8.242% and 2.77%, respectively, can result from an increase in the condenser cooling seawater temperature by about 15–30°C, Fouling Factor of seawater and treated boiler feed water by about 0.00015–0.00035 and 0.00005–0.00015 m² K/W, respectively, and salinity by about 0–100 g/kg. This paper investigates three real practical Factors that have been proved to have significant adverse effects on the thermal efficiency of nuclear power plants.

  • The influence of condenser cooling seawater Fouling on the thermal performance of a nuclear power plant
    Annals of Nuclear Energy, 2015
    Co-Authors: Said M.a. Ibrahim, Sami I. Attia
    Abstract:

    Abstract This study performs a thermodynamic analysis and energy balance to study the effect of Fouling change on the thermal performance of the condenser and the thermal efficiency of a proposed nuclear power plant. The study is carried out on a pressurized water reactor nuclear power plant. The results of the study show that the increasing of Fouling Factor decreases the power output and the thermal efficiency of the nuclear power plant. The main results of this study is that the impact of an increase in the condenser cooling seawater Fouling Factor in the range 0.00015–0.00035 m 2  K/W is led to a decrease in the plant output power and thermal efficiency of 1.36% and 0.448%, respectively. The present paper researches into a real practical Factor that has significant negative effect on the thermal efficiency of the nuclear power plants, which is Fouling of condenser cooling seawater. This is abundantly important since one of the top goals of new power stations are to increase their thermal efficiency, and to prevent or minimize the reasons that lead to loss of output power.

Narmine H. Aly - One of the best experts on this subject based on the ideXlab platform.

  • Thermal performance of seawater desalination systems
    Desalination, 2003
    Co-Authors: Narmine H. Aly, Adel K. El-fiqi
    Abstract:

    This work describes a steady-state mathematical model developed to analyze both the multi-stage and multi-effect desalination systems. For MSF the model accounts for the geometry of the stages, the mechanism of heat transfer, and the variation of the physical properties of seawater with temperature and salinity. In addition, the model takes into consideration the role of Fouling and its effect on the plant performance ratio. Relationships among the parameters controlling the product water cost to other operating and design parameters are presented. These parameters include plant performance ratio, specific flow rate of recirculating brine, top brine temperature, and specific heat transfer area. These relationships are used for studying a typical operating plant. The results obtained by the model are compared with data from the Sidi-Krir plant in west Alexandria, which contains 17 recovery and three rejection stages. There is good agreement between the calculated results and the plant data. The model results are also used to study the different operating conditions such as part load; for example, the effect of decreasing the recirculated flow rate and/or the top brine temperature on the unit performance ratio. In addition, the effect of decreasing the seawater temperature below the design value shows an increase in the unit production rate, while increasing the Fouling Factor reduces the plant production rate. For MED, the effect of the process variables on the performance of a "forward type" multi-effect boiling falling film is carried out. This includes the effect of number of effects and top brine temperature on performance ratio. In addition, the influence of these Factors on the specific heat transfer area and the effect of seawater inlet temperature on the performance ratio are investigated. The effect of the top brine temperature and the temperature difference per effect on the performance ratio, the specific heat transfer area, and the cooling brine flow rate are also investigated. The study results indicate that the performance ratio is completely dependent on the number of effects and slightly dependent on the top brine temperature.

Khalid Bamardouf - One of the best experts on this subject based on the ideXlab platform.

  • Optimization of hybridized seawater desalination process
    Desalination, 2000
    Co-Authors: Mohammad A.k. Al-sofi, Osman A. Hamed, Ata M. Hassan, Abdul Ghani I. Dalvi, Mohammad N.m. Kither, Ghulam M. Mustafa, Khalid Bamardouf
    Abstract:

    Saline Water Conversion Corporation (SWCC), Research and Development Center (RDC) came up in recent years with a breakthrough in feed treatment to all desalination processes. Selective ions, biomass and suspended solids rejection characteristic of nanofiltration (NF) membranes were utilized to retard the ingress of hardness forming ions and other foulants into desalination downstream processing steps, e.g. SWRO and MSF. NF pretreatment using brackish water hardness removal membranes were applied to seawater pilot, demonstration and eventually commercial desalination plants. A good number of such membranes were tested in order to select the best. The screening scheme revealed couple of interesting facts related to characteristics of various brands and grades of NF membranes. In an earlier stage of this multi phase project these membranes were categorized as groups A, B and C. These groups in the same order were found to give from high hardness and salinity rejection with low flow and product recovery down to low rejection with high flow and recovery. Based on the above findings, it was decided that the most suitable membranes would be those of group B which could give good flow and recovery with reasonable rejections. Membranes of group B were tested at various plant sizes, production schemes and configurations. This paper will concentrate on 4, 8 and 9 inch membrane elements used in NF or NF/SWRO combination to provide make-up to pilot plant MSF of 20 kl/d distiller. Such hybridized production configurations were optimized by testing overall performance. Few prime parameters were closely analyzed to come up with the best combination of NF membrane brand and their operating parameters along with MSF and/or SWRO-MSF hybrid conditions. In the latter case SWRO reject was used as make-up to the MSF pilot plant distiller. Moreover, the testing program locked into further hybridization, whereby MSF heated reject water was used as feed to NF pretreatment section. This was done to establish the effect of feed temperature rise benefits on NF and/or NF-SWRO energy input, yield(s) and product(s) flow and quality. The MSF operation was monitored and its operating results were analyzed. Main components of such analyses were gain output ratio (GOR), Fouling Factor (FF), top brine temperature (TBT), chemical consumption and product to make-up yield ratio and its quality.

Said M.a. Ibrahim - One of the best experts on this subject based on the ideXlab platform.

  • The combined effect of changes in the condenser cooling seawater temperature, Fouling and salinity on the thermal performance of a pressurised water reactor nuclear power plant
    International Journal of Nuclear Energy Science and Technology, 2015
    Co-Authors: Said M.a. Ibrahim, Sami I. Attia
    Abstract:

    This study presents the effect of temperature, Fouling Factor and salinity of the condenser cooling seawater and adverse effect on the thermal performance of a nuclear power plant. These are the most important Factors affecting the condenser performance. The study is carried out on a pressurised water reactor nuclear power plant. The results showed that a loss in the plant output power and thermal efficiency of up to 8.242% and 2.77%, respectively, can result from an increase in the condenser cooling seawater temperature by about 15–30°C, Fouling Factor of seawater and treated boiler feed water by about 0.00015–0.00035 and 0.00005–0.00015 m² K/W, respectively, and salinity by about 0–100 g/kg. This paper investigates three real practical Factors that have been proved to have significant adverse effects on the thermal efficiency of nuclear power plants.

  • The influence of condenser cooling seawater Fouling on the thermal performance of a nuclear power plant
    Annals of Nuclear Energy, 2015
    Co-Authors: Said M.a. Ibrahim, Sami I. Attia
    Abstract:

    Abstract This study performs a thermodynamic analysis and energy balance to study the effect of Fouling change on the thermal performance of the condenser and the thermal efficiency of a proposed nuclear power plant. The study is carried out on a pressurized water reactor nuclear power plant. The results of the study show that the increasing of Fouling Factor decreases the power output and the thermal efficiency of the nuclear power plant. The main results of this study is that the impact of an increase in the condenser cooling seawater Fouling Factor in the range 0.00015–0.00035 m 2  K/W is led to a decrease in the plant output power and thermal efficiency of 1.36% and 0.448%, respectively. The present paper researches into a real practical Factor that has significant negative effect on the thermal efficiency of the nuclear power plants, which is Fouling of condenser cooling seawater. This is abundantly important since one of the top goals of new power stations are to increase their thermal efficiency, and to prevent or minimize the reasons that lead to loss of output power.