Numerical Simulation on Fouling of the Steam Cooler in a Power Plant

2013 ◽  
Vol 291-294 ◽  
pp. 1969-1974
Author(s):  
Wei Liang Cheng ◽  
An Di ◽  
Li Chao Liu ◽  
Lian Guang Liu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchange ◽  
Power Plant ◽  
Power Plants ◽  
Engineering Application ◽  
Flow State ◽  
Equipment Safety ◽  
Heat Exchange Tube ◽  
Reasonable Model

The fouling in the heat transfer devices of power plants, not only changes the fluid flow state designed, but also counteracts the heat transfer, so the equipment safety and economy are reduced. The adsorption and deposition about fouling is a quite complicated chemical and physical process, and it is difficult to obtain an accurate and reasonable model and its engineering application. Therefore, under some different conditions such as velocity, temperature and concentration of fouling and pipe position, the numerical simulation is obtained in the power plant steam cooler. The temperature inside the pipe is gradually decreased with the velocity. At the same time, the fouling increases in the first half of the exchanger pipe, and easily appears near regions of entrance more and more. The fouling may occurs at the outlet position of the heat exchange tube. Under the same conditions the heat exchange tube near centre line is easier to bring the fouling.

scholarly journals Numerical Simulation of Intrachamber Processes in the Power Plant

2021 ◽  
Vol 11 (11) ◽  
pp. 4990
Author(s):  
Boris Benderskiy ◽  
Peter Frankovský ◽  
Alena Chernova
Keyword(s):  
Numerical Simulation ◽  
Power Plant ◽  
Flow Structure ◽  
Power Plants ◽  
Control Volume ◽  
Conjugate Problem ◽  
Topological Features ◽  
Gas Dynamic ◽  
Calculation Results ◽  
Volume Method

This paper considers the issues of numerical modeling of nonstationary spatial gas dynamics in the pre-nozzle volume of the combustion chamber of a power plant with a cylindrical slot channel at the power plant of the mass supply surface. The numerical simulation for spatial objects is based on the solution conjugate problem of heat exchange by the control volume method in the open integrated platform for numerical simulation of continuum mechanics problems (openFoam). The calculation results for gas-dynamic and thermal processes in the power plant with a four-nozzle cover are presented. The analysis of gas-dynamic parameters and thermal flows near the nozzle cover, depending on the canal geometry, is given. The topological features of the flow structure and thermophysical parameters near the nozzle cap were studied. For the first time, the transformation of topological features of the flow structure in the pre-nozzle volume at changes in the mass channel’s geometry is revealed, described, and analyzed. The dependence of the Nusselt number in the central point of stagnation on the time of the power plants operation is revealed.

scholarly journals Comparative Modeling of a Parabolic Trough Collectors Solar Power Plant with MARS Models

Energies ◽  
2017 ◽  
Vol 11 (1) ◽  
pp. 37 ◽  
Author(s):  
Jose Rogada ◽  
Lourdes Barcia ◽  
Juan Martinez ◽  
Mario Menendez ◽  
Francisco de Cos Juez
Keyword(s):  
Heat Transfer ◽  
Water Vapor ◽  
Power Plant ◽  
Solar Radiation ◽  
Thermal Energy ◽  
Power Plants ◽  
Solar Power ◽  
Rankine Cycle ◽  
Heat Transfer Fluid ◽  
Solar Field

Power plants producing energy through solar fields use a heat transfer fluid that lends itself to be influenced and changed by different variables. In solar power plants, a heat transfer fluid (HTF) is used to transfer the thermal energy of solar radiation through parabolic collectors to a water vapor Rankine cycle. In this way, a turbine is driven that produces electricity when coupled to an electric generator. These plants have a heat transfer system that converts the solar radiation into heat through a HTF, and transfers that thermal energy to the water vapor heat exchangers. The best possible performance in the Rankine cycle, and therefore in the thermal plant, is obtained when the HTF reaches its maximum temperature when leaving the solar field (SF). In addition, it is necessary that the HTF does not exceed its own maximum operating temperature, above which it degrades. The optimum temperature of the HTF is difficult to obtain, since the working conditions of the plant can change abruptly from moment to moment. Guaranteeing that this HTF operates at its optimal temperature to produce electricity through a Rankine cycle is a priority. The oil flowing through the solar field has the disadvantage of having a thermal limit. Therefore, this research focuses on trying to make sure that this fluid comes out of the solar field with the highest possible temperature. Modeling using data mining is revealed as an important tool for forecasting the performance of this kind of power plant. The purpose of this document is to provide a model that can be used to optimize the temperature control of the fluid without interfering with the normal operation of the plant. The results obtained with this model should be necessarily contrasted with those obtained in a real plant. Initially, we compare the PID (proportional–integral–derivative) models used in previous studies for the optimization of this type of plant with modeling using the multivariate adaptive regression splines (MARS) model.

Research on Electric and I&C Equipment Safety Function Classification of Nuclear Power Plant

2021 ◽  
Author(s):  
Wang Yuqi ◽  
Sun Qian
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Function Analysis ◽  
System Component ◽  
Design Work ◽  
Equipment Safety ◽  
Safety Function

Abstract Classification of System, Component and Structure (SSC) is the base as well as high level demand of nuclear power plant. Equipment classification including electric and Instrument and Control (I&C) equipment is the precondition of correct design regulation and standard. Safety function classification is key pass of electric and I&C equipment classification. This paper researches the method of nuclear power plant electric and I&C equipment safety function classification. Firstly from view of function, it explains the importance of function classification. Then function analysis and classification of equipment is implemented by design order. Lastly from view of accident analysis, function classification is validated, and a complete approach of function classification is formed. The purpose of this paper is the NPP electric and I&C equipment safety function classification as an example, to study and summarize the method of the electric and I&C equipment safety function classification, and to provide the basis for specific items design work according to design requirements. At the same time, a practical method is provided for other similar NPP electric and I&C equipment classification work. The electric and I&C equipment function classification of nuclear power plant satisfy the basic principles requirement of relative nuclear power rules and codes. It provides an important basis of equipment classification for next nuclear power plants.

Influence of a Variable in Time Heat Transfer Coefficient on Stresses in Model of Power Plant Components

2013 ◽  
Author(s):  
Jerzy Okrajni ◽  
Mariusz Twardawa
Keyword(s):  
Heat Transfer ◽  
Power Plant ◽  
Mechanical Behaviour ◽  
Power Plants ◽  
Thermal Loading ◽  
Computer Modelling ◽  
Temperature Fields ◽  
Fluid Medium ◽  
Stress Changes ◽  
Plant Components

The paper discusses the issue of modelling of strains and stresses resulting from heating and cooling processes of components in power plants. The main purpose of the work is to determine the mechanical behaviour of power plant components operating under mechanical and thermal loading. Finite element method (FEM) has been used to evaluate the temperature and stresses changes in components as a function of time. Temperature fields in the components of power plants are dependent, among parameters, on variable heat-transfer conditions between components and the fluid medium, which may change its condition, flowing inside them. For this reason, evaluation of the temperature field and the consequent stress fields requires the use of heat-transfer coefficients as time-dependent variables and techniques for determining appropriate values for these coefficients should be used. The methodology of combining computer modelling of the temperature fields with its measurements performed at selected points of the pipelines may be used in this case. The graphs of stress changes as a function of time have been determined for the chosen plant components. The influence of the heat transfer conditions on the temperature fields and mechanical behaviour of components have been discussed.

3D Numerical Simulation of Fluid Flow and Heat Transfer for Asymmetric Spiral-Gear Inserts in a Tube

2011 ◽  
Vol 130-134 ◽  
pp. 1686-1690 ◽  
Author(s):  
De Qi Peng ◽  
Wei Qiang Wang ◽  
Tian Lan Yu ◽  
Biao Wei ◽  
Yu Zhou ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Fluid Flow ◽  
Tube Wall ◽  
Convection Heat Transfer ◽  
Engineering Application ◽  
Tangential Velocity ◽  
Smooth Tube ◽  
Tube Heat Exchanger ◽  
Flow And Heat Transfer

For solving cleaning fouling online for shell-and-tube heat exchanger，an asymmetric spiral-gear cleaning technology is presented. The RNGk-εturbulent model is used to simulate the fluid flow and heat transfer of the tube with the spiral-gear. Its velocity and turbulent intensity field, convection heat transfer characteristic and resistance property are analyzed. Numerical simulation results shows that radial velocity is larger in the annular area near the tube wall than that in the smooth tube. Tangential velocity in the diameter area corresponding to the width of spiral-gear insertion increases with radius，but it decreases with radius in the annular clearance between the insert and the tube wall. However, fluid tangential motion of the smooth tube is only stochastic，and its tangential velocity is lower several orders of magnitude than that for the tube with the insertions. The average surface heat transfer coefficient of the spiral-gear-inserted tube wall is increased nearly 88% than that from the smooth tube wall. In addition, the pressure drop caused by spiral-gear inserts is in the permissible range of engineering application. The inserts is applicable to the heat exchangers at a flow rate lower than 0.8 m·s-1.

CFD-Based Study of Velocity and Temperature Distribution among Rib-Tube in Heat Environment

2014 ◽  
Vol 487 ◽  
pp. 558-561
Author(s):  
Su Hou De ◽  
Zhang Yu Fu ◽  
Che Ji Yong ◽  
Wu Shi Lei ◽  
Xiao Long Wen
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Heat Exchange ◽  
Temperature Distribution ◽  
Velocity Distribution ◽  
Engineering Application ◽  
Dispersed Phase ◽  
Wall Function ◽  
Governing Equations ◽  
Theory Analysis

The velocity distribution coupled thermal and fluid flow a rib-tube was studied in this article. Based on theory analysis and numerical simulation, we choose modal and wall function to simulate the flow in rib-tube, velocity to definite the dispersed phase. The governing equations were built and solved by numerical way. The progress of flow and heat exchange in rib-tube, the rules and contours of temperature, velocity were obtained, they shows that, along the rib-tube, velocity was changed with the temperature rising , which could give us a reference for engineering application .

Numerical Simulation of Stress and Deformation on Heat Transfer

2011 ◽  
Vol 422 ◽  
pp. 842-845
Author(s):  
Xue Ping Wang ◽  
Ying Zhang ◽  
Pan Li ◽  
Zhen Wei Zhang
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Heat Exchange ◽  
Structure Design ◽  
Stress And Strain ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Stress And Deformation

This paper primarily simulates the heat exchange part’s stress and strain situation under the load of temperature and gravity and their coupling impact aiming at obtaining the stress and deformation distribution. The authors took advantage of the method of the finite element analysis to study the stress and strain situation. Through the analysis, each part of the transfer’s stress and strain can be calculated. The conclusion of this paper provides the basis for the further enhancement of the machine life and optimization of the structure design.

Simulation and Research of a Thermal Type Liquid Flow Sensor

2012 ◽  
Vol 562-564 ◽  
pp. 1213-1217
Author(s):  
Feng Tian ◽  
Zhen Bin Gao ◽  
Yi Cai Sun
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchange ◽  
Temperature Distribution ◽  
Flow Sensor ◽  
Turbulent Heat Transfer ◽  
Turbulent Heat ◽  
Water Flow Velocity ◽  
Detection Circuit ◽  
Flow Detection

A flow sensor for liquids, based on the principle of fluid-structure heat transfer is presented. The heater and thermistor are integrated and wrapped together as a detector and heat source, allowing heat exchange between the sensor and the fluid. Through numerical simulation, the temperature distribution of the sensor was investigated, under conditions of various flow velocities. The process of turbulent heat transfer in the flow pipe was simulated, the temperature distribution in the sensor was analyzed and compared under different temperature and velocity of the fluid, and the corresponding measuring ranges were determined. The flow detection circuit is designed and the results of water flow velocity tests in the range of (0.01–1)m/s are presented.

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