This study presents the effect of non-uniform heat source on the magneto-hydrodynamic flow of nanofluid across an expanding plate with consideration of the homogeneous-heterogeneous reactions and thermal radiation eff...This study presents the effect of non-uniform heat source on the magneto-hydrodynamic flow of nanofluid across an expanding plate with consideration of the homogeneous-heterogeneous reactions and thermal radiation effects.A nanofluid’s dynamic viscosity and effective thermal conductivity are specified with Corcione correlation.According to this correlation,the thermal conductivity is carried out by the Brownian motion.Similarity transformations reduce the governing equations concerned with energy,momentum,and concentration of nanofluid and then numerically solved.The influences of the effective parameters,e.g.,the internal heat source parameters,the volume fraction of nanofluid,the radiation parameter,the homogeneous reaction parameter,the magnetic parameter,the heterogeneous parameter and the Schmidt number are studied on the heat and flow transfer features.Further,regarding the effective parameters of the present work,the correlation for the Nusselt number has been developed.The outcomes illustrate that with the raising of the heterogeneous parameter and the homogeneous reaction parameter,the concentration profile diminishes.In addition,the outcomes point to a reverse relationship between the Nusselt number and the internal heat source parameters.展开更多
This research presents neutronic calculations for heavy water research reactor core substituting hydride fuel for uranium dioxide fuel. The aim of this research is feasibility analysis of reactor utilization with its ...This research presents neutronic calculations for heavy water research reactor core substituting hydride fuel for uranium dioxide fuel. The aim of this research is feasibility analysis of reactor utilization with its original design using a new proposed fuel and changing the coolant and moderator circuit to light water. The required group constants for the CITATION code will be calculated using WIMSD-4 code. Neutronic calculations such as multiplication factors, radial and axial power peaking factor and fuel burn-up calculations are carried out by the CITATION code.展开更多
New researches on serious public health problems such as respiratory disease, heart attacks, and premature deaths, show the threat of air and environmental pollution on human＇s health. Exhausting greenhouse gases for...New researches on serious public health problems such as respiratory disease, heart attacks, and premature deaths, show the threat of air and environmental pollution on human＇s health. Exhausting greenhouse gases for electrical energy production in fossil fueled power plants is one of the major reasons of environmental pollutions. Increasing energy demand has made global concerns about the environmental pollutions of fossil power plants. In this article, fossil power plant productive pollutants such as Sulfur Dioxide, Mercury, and Carbon Dioxide, are investigated. On the other hand, nuclear power plant and its produced waste are discussed as the future power generation source. In this article, fossil and nuclear power plants are compared as power sources, pollutants, and their environmental effects. First, investigations are made on fossil power plants and their effects on environment and climate changes. On the other hand, nuclear power plants are discussed as a possible replacement for fossil power plants. In this part, effects of radiation on human health and environment like important nuclear accidents are investigated. This paper summarizes several types of power plants and it is deduced that the nuclear power plant is more clean energy producer in comparison to other power plants.展开更多
A permanent magnet BLDC(brushless direct current) motor is used to move the control rod of a miniature neutron source reactor(MNSR). The BLDC motor drive is modeled using MATLAB/SIMULINK. Two main parts of the modelin...A permanent magnet BLDC(brushless direct current) motor is used to move the control rod of a miniature neutron source reactor(MNSR). The BLDC motor drive is modeled using MATLAB/SIMULINK. Two main parts of the modeling are the inverter switching and the current control. Current control with chopping used to minimize the torque ripple of the MNSR control rod drive. Fuzzy logic current control together with soft chopping control shows the best response of all the three strategies. The prototype drive mechanism has an ATmega32 controller and power MOSFET switches. The simulation results are compared with experimental drive mechanism.展开更多
This paper reports on the modeling and simulation of flashing-induced instabilities in naturalcirculation systems, with special emphasis on simplified boiling water reactors (SBWRs). In this work, flashing-induced osc...This paper reports on the modeling and simulation of flashing-induced instabilities in naturalcirculation systems, with special emphasis on simplified boiling water reactors (SBWRs). In this work, flashing-induced oscillations have been studied by using an experimental test facility (SIRIUS-N) and RELAP5/MOD3.2 thermal hydraulic code. The behavior of the test facility is investigated for different values of core inlet temperature value. The results of the simulations have been compared qualitatively and quantitatively with experiments. In general, deviations are found between the numerical and experimental results, in spite of the close similarity between the SIRIUS-N facility and the definition of the system in the RELAP code. This result indicates that predictions regarding experimental facility, based on modeled system, should be carefully considered.展开更多
In a gas turbine power plant,the lubrication oil must be hot enough for the turbine start-up where the unit is in standstill mode.Currently,the strategy to heat the lubrication oil of ANSALDO V94.2 gas turbine power p...In a gas turbine power plant,the lubrication oil must be hot enough for the turbine start-up where the unit is in standstill mode.Currently,the strategy to heat the lubrication oil of ANSALDO V94.2 gas turbine power plant is operating the units in turning gear mode or interval mode.However,these strategies cause to suffering the power plant from high power consumption rate and aging.In this study,an auxiliary portable heating system was added to the unit 5 of the MAPNA built MGT-70(an Iranian version of V94.2)Aliabad Katoul-Iran power plant for increasing the lube oil temperature.Irreversibility,cost-effectiveness,and availability of the proposed heating system are studied by the concepts of exergy,economy,and reliability analyses,respectively.The result of the exergy analysis shows that by using the auxiliary portable lube oil heating system the exergy destruction decreases about 94.7%and 92.6%in comparison with turning gear mode and interval mode,respectively.The result of the economic analysis shows that the auxiliary portable heating system consumes less power rather than turning gear mode.Moreover,it is a cost-effective system which has no penalty and no non-profit production.Finally,the reliability analysis shows that the auxiliary portable lube oil heating system is a reliable tool during its lifetime.展开更多
文摘This study presents the effect of non-uniform heat source on the magneto-hydrodynamic flow of nanofluid across an expanding plate with consideration of the homogeneous-heterogeneous reactions and thermal radiation effects.A nanofluid’s dynamic viscosity and effective thermal conductivity are specified with Corcione correlation.According to this correlation,the thermal conductivity is carried out by the Brownian motion.Similarity transformations reduce the governing equations concerned with energy,momentum,and concentration of nanofluid and then numerically solved.The influences of the effective parameters,e.g.,the internal heat source parameters,the volume fraction of nanofluid,the radiation parameter,the homogeneous reaction parameter,the magnetic parameter,the heterogeneous parameter and the Schmidt number are studied on the heat and flow transfer features.Further,regarding the effective parameters of the present work,the correlation for the Nusselt number has been developed.The outcomes illustrate that with the raising of the heterogeneous parameter and the homogeneous reaction parameter,the concentration profile diminishes.In addition,the outcomes point to a reverse relationship between the Nusselt number and the internal heat source parameters.
文摘This research presents neutronic calculations for heavy water research reactor core substituting hydride fuel for uranium dioxide fuel. The aim of this research is feasibility analysis of reactor utilization with its original design using a new proposed fuel and changing the coolant and moderator circuit to light water. The required group constants for the CITATION code will be calculated using WIMSD-4 code. Neutronic calculations such as multiplication factors, radial and axial power peaking factor and fuel burn-up calculations are carried out by the CITATION code.
文摘New researches on serious public health problems such as respiratory disease, heart attacks, and premature deaths, show the threat of air and environmental pollution on human＇s health. Exhausting greenhouse gases for electrical energy production in fossil fueled power plants is one of the major reasons of environmental pollutions. Increasing energy demand has made global concerns about the environmental pollutions of fossil power plants. In this article, fossil power plant productive pollutants such as Sulfur Dioxide, Mercury, and Carbon Dioxide, are investigated. On the other hand, nuclear power plant and its produced waste are discussed as the future power generation source. In this article, fossil and nuclear power plants are compared as power sources, pollutants, and their environmental effects. First, investigations are made on fossil power plants and their effects on environment and climate changes. On the other hand, nuclear power plants are discussed as a possible replacement for fossil power plants. In this part, effects of radiation on human health and environment like important nuclear accidents are investigated. This paper summarizes several types of power plants and it is deduced that the nuclear power plant is more clean energy producer in comparison to other power plants.
基金Supported by Research Contract of the Islamic Azad University’s Aliabad Katoul branch
文摘A permanent magnet BLDC(brushless direct current) motor is used to move the control rod of a miniature neutron source reactor(MNSR). The BLDC motor drive is modeled using MATLAB/SIMULINK. Two main parts of the modeling are the inverter switching and the current control. Current control with chopping used to minimize the torque ripple of the MNSR control rod drive. Fuzzy logic current control together with soft chopping control shows the best response of all the three strategies. The prototype drive mechanism has an ATmega32 controller and power MOSFET switches. The simulation results are compared with experimental drive mechanism.
文摘This paper reports on the modeling and simulation of flashing-induced instabilities in naturalcirculation systems, with special emphasis on simplified boiling water reactors (SBWRs). In this work, flashing-induced oscillations have been studied by using an experimental test facility (SIRIUS-N) and RELAP5/MOD3.2 thermal hydraulic code. The behavior of the test facility is investigated for different values of core inlet temperature value. The results of the simulations have been compared qualitatively and quantitatively with experiments. In general, deviations are found between the numerical and experimental results, in spite of the close similarity between the SIRIUS-N facility and the definition of the system in the RELAP code. This result indicates that predictions regarding experimental facility, based on modeled system, should be carefully considered.
文摘In a gas turbine power plant,the lubrication oil must be hot enough for the turbine start-up where the unit is in standstill mode.Currently,the strategy to heat the lubrication oil of ANSALDO V94.2 gas turbine power plant is operating the units in turning gear mode or interval mode.However,these strategies cause to suffering the power plant from high power consumption rate and aging.In this study,an auxiliary portable heating system was added to the unit 5 of the MAPNA built MGT-70(an Iranian version of V94.2)Aliabad Katoul-Iran power plant for increasing the lube oil temperature.Irreversibility,cost-effectiveness,and availability of the proposed heating system are studied by the concepts of exergy,economy,and reliability analyses,respectively.The result of the exergy analysis shows that by using the auxiliary portable lube oil heating system the exergy destruction decreases about 94.7%and 92.6%in comparison with turning gear mode and interval mode,respectively.The result of the economic analysis shows that the auxiliary portable heating system consumes less power rather than turning gear mode.Moreover,it is a cost-effective system which has no penalty and no non-profit production.Finally,the reliability analysis shows that the auxiliary portable lube oil heating system is a reliable tool during its lifetime.
