scholarly journals A simulation study of processes for mixing non-isothermal flows under dynamic effects

2020 ◽  
Author(s):  
Aleksandr Sataev ◽  
Vyacheslav Andreev ◽  
Denis Novikov ◽  
Julia Perevezentseva
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Vertical Component ◽  
Dynamic Force ◽  
Mixing Processes ◽  
Periodic Effect ◽  
Temperature Pulsations ◽  
Isothermal Flows ◽  
Isothermal Water

The processes for mixing of non-isothermal streams essentially define the parameters of the heat-carrier on an input in a core in modes with incomplete structure of the working equipment and, as a consequence, - a heat engineering condition of a core. Besides, the task of researching the temperature pulsations accompanying practically all modes of currents for non-isothermal streams is extremely relevant, as these pulsations lead to additional thermocyclic loadings on elements of the equipment and in many cases define its resource. The paper describes the research of mixing processes for non-isothermal water coolant flows in hydraulic model of ship nuclear power plant. In several experiments, attention was paid to the mixing processes when feeding non-isothermal flows through the circulation loops located opposite of each other. To simulate the effect of external dynamic force in the form of periodic effect on the spatial orientation of the model, the ship was tested on a stand "Swinging platform". These vibrations affected the mixing processes occurring within the model. The main impact they had on the transition time, temperature gradient, vertical component of the velocity projection. In the future, these parameters will be clarified and the influence of other factors on the mixing of non-isothermal flows in the ship's nuclear power plant will be studied in more detail.

Experimental Investigations on the Prototypic Steam Explosion

2005 ◽  
Author(s):  
J. H. Song ◽  
J. H. Kim ◽  
B. T. Min ◽  
S. W. Hong
Keyword(s):  
Experimental Data ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Test Section ◽  
Steam Explosion ◽  
Nuclear Power ◽  
Weight Percent ◽  
Experimental Investigations ◽  
Dynamic Force ◽  
Reference Case

This paper discusses results of a series of steam experiments using a prototypic material representing the molten core of nuclear power plant. Five experiments are discussed in detail in addition to a brief review of the previous experiments, where the focuses were on the effect of corium composition and external trigger on the strength of the steam explosion. A mixture of UO2:ZrO2 is used for the experiment, where the weight percent of each component is changed. One experiment was performed with corium at a composition of 70:30 without an external trigger as a reference case. Three tests were performed by using corium at the same composition with an external trigger. The last experiment was performed using corium at a composition of 80:20 with an external trigger. Various parameters are measured including the dynamic pressures on the wall of the test section and the dynamic force at the bottom of the test section. From the experimental data, the strength of the steam explosion was evaluated. It is shown that the strength of the steam explosion highly depends on the composition. A comparison between the cases with an external trigger and the cases without external trigger indicates that there is no substantial escalation of the strength of the explosion due to an external trigger.

scholarly journals Visualization of Non-Isothermal Liquids Mixing Processes Under the Influence of External Forces

2021 ◽  
Author(s):  
Alexandr Sataev ◽  
Vyacheslav Andreev
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Dynamic Mode ◽  
Loop Model ◽  
Mixing Process ◽  
Mixing Processes ◽  
Static Mode ◽  
Experimental Stand ◽  
External Forces

The paper presents a visualization of the mixing processes of non-isothermal flows in the model of a ship's nuclear power plant under static and dynamic modes. The values obtained at the experimental stand served as the database for visualization. It is a four-loop model of the flow part of a ship's nuclear power plant. To create a dynamic mode (oscillations in one plane), the model is placed on a swinging platform. This paper shows the processes occurring during periodic pitching with a period of 4 seconds and amplitude of 15 degrees. The descending annular section of the circulation tract was chosen as the object of research. Then the resulting database was visualized using the 3DFieldPro program, where a color scale was matched to the temperature data and model coordinates, and also with the help of the OpenCV library with a high-level implementation program С++, the characteristic hot/cold vortices (spots), the boundary of the mixing process, its character in static mode (without fluctuations) and dynamic mode were analyzed. The uneven mixing process was noted, especially in the dynamic mode. The resulting tools allow you to quickly and clearly visualize these processes.

Fuzzy multi-objective decision making approach for nuclear power plant installation

2020 ◽  
Vol 39 (5) ◽  
pp. 6339-6350
Author(s):  
Esra Çakır ◽  
Ziya Ulukan
Keyword(s):  
Linear Programming ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Energy Supply ◽  
Energy Demand ◽  
Nuclear Power ◽  
Power Plants ◽  
Total Duration ◽  
Objective Functions ◽  
Multi Objective

Due to the increase in energy demand, many countries suffer from energy poverty because of insufficient and expensive energy supply. Plans to use alternative power like nuclear power for electricity generation are being revived among developing countries. Decisions for installation of power plants need to be based on careful assessment of future energy supply and demand, economic and financial implications and requirements for technology transfer. Since the problem involves many vague parameters, a fuzzy model should be an appropriate approach for dealing with this problem. This study develops a Fuzzy Multi-Objective Linear Programming (FMOLP) model for solving the nuclear power plant installation problem in fuzzy environment. FMOLP approach is recommended for cases where the objective functions are imprecise and can only be stated within a certain threshold level. The proposed model attempts to minimize total duration time, total cost and maximize the total crash time of the installation project. By using FMOLP, the weighted additive technique can also be applied in order to transform the model into Fuzzy Multiple Weighted-Objective Linear Programming (FMWOLP) to control the objective values such that all decision makers target on each criterion can be met. The optimum solution with the achievement level for both of the models (FMOLP and FMWOLP) are compared with each other. FMWOLP results in better performance as the overall degree of satisfaction depends on the weight given to the objective functions. A numerical example demonstrates the feasibility of applying the proposed models to nuclear power plant installation problem.

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