Mathematical model of steam generator feed system at power unit of nuclear plant

2011 ◽  
Vol 72 (5) ◽  
pp. 1118-1126 ◽  
Author(s):  
E. M. Raskin ◽  
L. A. Denisova ◽  
V. P. Sinitsyn ◽  
Yu. V. Nesterov
Keyword(s):  
Mathematical Model ◽  
Power Unit ◽  
Steam Generator ◽  
Nuclear Plant ◽  
Feed System

Investigation Tests of the P-134 Heat-Recovery Steam Generator Used as Part of the PGU-230T Combined-Cycle Power Unit

2019 ◽  
Vol 66 (5) ◽  
pp. 331-339
Author(s):  
M. N. Maidanik ◽  
A. N. Tugov ◽  
N. I. Mishustin ◽  
A. E. Zelinskii
Keyword(s):  
Power Unit ◽  
Steam Generator ◽  
Heat Recovery ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator

Current Forgings and their Properties for Steam Generator of Nuclear Plant

2009 ◽  
pp. 56-56-9 ◽  
Author(s):  
H Tsukada ◽  
K Suzuki ◽  
M Kusuhashi ◽  
I Sato
Keyword(s):  
Steam Generator ◽  
Nuclear Plant

Establishment and Analysis of Mathematical Model of the Accuracy Identification of Five-Axis CNC Machine Tools

2014 ◽  
Vol 945-949 ◽  
pp. 1700-1706
Author(s):  
Rong Bo Shi ◽  
Zhi Ping Guo ◽  
Zhi Yong Song
Keyword(s):  
Mathematical Model ◽  
Machine Tools ◽  
Theoretical Research ◽  
Cnc Machine Tools ◽  
Cnc Machine ◽  
Feed System ◽  
Kinematics Model ◽  
Five Axis

This paper studies control and motion theory of feed system of the five-axis CNC machine tools, propose the method of establish mathematical model, kinematics model of the feed system, in order to provide a method of theoretical research for accuracy identification of five-axis CNC machine tools.

scholarly journals Mathematical simulation of hard excitation of cavitation self-oscillations in a liquid-propellant rocket engine feed system

2021 ◽  
Vol 2021 (1) ◽  
pp. 29-36
Author(s):  
S.I. Dolgopolov ◽  
Keyword(s):  
Mathematical Model ◽  
Mathematical Simulation ◽  
Small Amplitude ◽  
External Disturbance ◽  
Liquid Propellant ◽  
Feed System ◽  
Hard Excitation ◽  
Set Up ◽  
Pump Inlet ◽  
Propellant Rocket

Hard self-oscillation excitation differs from soft excitation in that self-oscillations are set up only if the initial departure of an oscillating system from equilibrium is strong enough. Experimental studies of cavitation oscillations in hydraulic systems with cavitating pumps of liquid-propellant rocket engines ((LPREs) include works that describe hard excitation of cavitation oscillations. By mow, hard excitation regimes have not been explained theoretically, to let alone their mathematical simulation. This paper presents a mathematical model of hard excitation of cavitation oscillations in a LPRE feed system, which comprises a mathematical model of cavitation self-oscillations in a LPRE feed system that accounts for pump choking and an external disturbance model. A mechanism of hard excitation of cavitation oscillations in a LPRE feed system is proposed. It is well known that hard excitation of cavitation self-oscillations may take place in cases where the pump feed system is near the boundary of the cavitation self-oscillation region. In this case, the self-oscillation amplitudes are small, and they are limited only by one nonlinearity (cavity volume vs. pump inlet pressure and flow relationship). Under excitation of sufficient intensity, the pump inlet pressure and flow find themselves in the choking characteristic; this may be responsible for choking and developed cavitation self-oscillations, which remain of interrupted type and do not go into the initial small-amplitude oscillations even after excitation removal. A mathematical simulation of hard excitation of cavitation self-oscillations was conducted to determine the parameters of cavitation self-oscillations in a bench feed system of a test pump. The simulation results show that without an external disturbance the pump system exhibits small-amplitude self-oscillations. On an external disturbance, developed (interrupted) cavitation oscillations are set up in the system, which is in agreement with experimental data. The proposed mathematical model of hard excitation of cavitation self-oscillations in a LPRE feed system allows one to simulate a case observed in an experiment in which it was possible to eliminate cavitation self-oscillations by an external disturbance.

scholarly journals Modeling of flexible nuclear power unit operational modes in the mathematical model of the Ukraine’s power system daily electric load profile dispatching

2021 ◽  
Vol 2021 (1) ◽  
pp. 29-37
Author(s):  
T.P. Nechaieva ◽  
Keyword(s):  
Mathematical Model ◽  
Power System ◽  
Power Unit ◽  
Nuclear Power ◽  
Storage Systems ◽  
Electric Load ◽  
Load Profile ◽  
Load Rate ◽  
Nuclear Power Unit ◽  
The Mathematical Model

The use of large amounts of existing baseload NPPs capacities with a significant increase in renewable generation in the mathematical model of optimal dispatching of generating capacities of Ukraine’s power system leads to a significant surplus of electricity during peak power generation at solar PV’s, which necessitates additional sources of flexibility of the power system, such as battery electricity storage systems. The projects of new advanced nuclear power units provide for their use in flexible load modes with a maximum unloading of up to 50% of the rated capacity. Advanced NPP power units with small modular reactors are designed for even greater more maneuverable operation with possible unloading of up to 20% of rated capacity. The article presents approaches to modeling the use of NPP power units in variable load modes in the mathematical model of the optimal daily load schedule dispatching of Integrated Power System of Ukraine. The first approach is to model the operation of NPP power units similar to modeling the participation of cycling TPP units in covering the daily electrical load profile of the power system, in particular, changes in generation power in the range from minimum to nominal load levels, load rate. The second approach is to determination for each nuclear power unit of variants of modes of their hourly loading, the choice of one of which is made as a result of optimization. The modeling results showed that the choice of optimal flexible loading modes of new nuclear power units allows to provide the load balance of the power system almost completely with available capacities, including cycling TPP units, and the use of pump-storage generating units to transfer excess PV generation at peak hours of electricity consumption, which avoids the use of battery storage systems. Keywords: mathematical model of dispatching, operational mode, nuclear power unit, daily electric load profile, power system

scholarly journals Experimental Investigation and Mathematical Modelling of Pressure Response for Steam Generator

2018 ◽  
Vol 7 (4.19) ◽  
pp. 960
Author(s):  
Mishaal A. AbdulKareem
Keyword(s):  
Mathematical Model ◽  
Time Delay ◽  
Water Temperature ◽  
Void Fraction ◽  
Steam Generator ◽  
Time Constant ◽  
Heating Power ◽  
Operating Pressure ◽  
Initial Water ◽  
Set Point

Cold startup of boiler is the process of boiler operation with water at ambient temperature and pressure with all intake and discharge valves are fully closed to permit fast development of pressure.  A mathematical model is developed to estimate the pressure response during cold startup of a perfectly insulated steam generator unit. A commercial type pressure switch is used in this unit to control and maintain the desired set point of the steam operating pressure. This mathematical model assume that the thermal properties of the supplied liquid water are temperature dependent. It is based on a novel Pressure Marching Technique that is coded using a FORTRAN language computer program. The maximum percentage error of (8.24 %) was obtained when comparing the predicted results of the mathematical model with the measured values obtained from the experimental test that was done using a (2 kW) electric steam generator unit with a volume of (30 litter) and maximum operating pressure of (8 bar). In addition, the same behavior of the predicted results was obtained when compared with results of a previously published article. It was found that the time constant of the pressure control system is directly proportional with its operating pressure set point and with the volume of the steam generator and its void fraction. A (50%) increase in the pressure set point will increase the time constant by (66.16%). Increasing the boiler volume by (166.667%) will increase the time constant by (166.677%) and increasing the boiler void fraction by (150%) will increase the time constant by (23.634%). The time constant is inversely proportional with the heating power of the steam generator. A (100%) increase in the heating power will decrease the time constant by (50%). The time constant is independent of the initial water temperature. Also, it was found that the time delay to start water evaporation is directly proportional with the volume of the steam generator. A (166.667%) increase in boiler volume will increase the time delay by (166.65%). The time delay is inversely proportional with the initial water temperature and with the heating power and void fraction of the steam generator. A (38.889%) increase in the initial water temperature will decrease the time delay by (8.882%). Increasing the heating power by (100%) will decrease the time delay by (50%) and increasing the boiler void fraction by (150%) will decrease the time delay by (16.665%). The time delay is independent on the operating pressure set point.  

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