Deceleration Performance and Parameter Influence Analysis of the Control Rod Hydraulic Deceleration Device for Control Rod Hydraulic Drive System

2019 ◽  
Vol 5 (3) ◽  
Author(s):  
Qin Benke ◽  
Li Leishi ◽  
Bo Hanliang
Keyword(s):  
Internal Control ◽  
Three Dimensional ◽  
Hydraulic Drive ◽  
Drive System ◽  
Field Analysis ◽  
Control Rod ◽  
Design And Optimization ◽  
Main Components ◽  
Technology Control ◽  
The Impact

Control rod hydraulic drive system (CRHDS), which is invented by INET, Tsinghua University, is a new type of internal control rod drive technology. Control rod hydraulic deceleration device (CRHDD), which consists of the plug, the hydraulic deceleration cylinder, etc., is one of the main components of the CRHDS. The CRHDD performs the rod dropping deceleration function through the interworking of the plug and the deceleration cylinder, which is filled with water, and reduces the rod dropping peak acceleration and the impact force acting upon the control rod to prevent the control rod cruciform blade from being deformed or damaged. The working mechanism of the CRHDD is presented and analyzed. The theoretical model of the control rod dropping process, which is based upon force analysis of the control rod during scram process, three-dimensional flow field analysis, and flow resistance calculation of the hydraulic deceleration cylinder, the kinematics and dynamics analysis of the control rod, is built whose results are compared and validated by the CRHDS scram test results. Then the model is used to analyze the influence of the key parameters, including the fuel case gap, the plug design clearance, the working temperature, etc. on the CRHDD working performance. The research results can give guidance for the design and optimization of the CRHDD.

Numerical and Experimental Analysis of the Control Rod Hydraulic Deceleration Device for the Control Rod Hydraulic Drive System

2017 ◽  
Author(s):  
Qin Benke ◽  
Li Leishi ◽  
Bo Hanliang
Keyword(s):  
Internal Control ◽  
Room Temperature ◽  
Three Dimensional ◽  
Hydraulic Drive ◽  
Drive System ◽  
Field Analysis ◽  
Control Rod ◽  
Design And Optimization ◽  
Main Components ◽  
The Impact

Control rod hydraulic drive system (CRHDS), which is invented by INET, Tsinghua University, is a new type of internal control rod drive technology. Control rod hydraulic deceleration device (CRHDD), which consists of the plug, the hydraulic deceleration cylinder, the hydraulic buffer, etc., is one of the main components of the CRHDS. The plug is connected with the top of the control rod driving shaft and moves along with the control rod inside the hydraulic deceleration cylinder. The CRHDD performs the rod dropping deceleration function through the interworking of the plug and the deceleration cylinder which is filled with water, and reduces the rod dropping peak acceleration and the impact force acting upon the control rod to prevent the control rod cruciform blade from being deformed or damaged. The working mechanism of the CRHDD is presented and analyzed. The rod dropping performance of the CRHDS was tested experimentally under room temperature. The theoretical model of the control rod dropping process, which is composed of the three dimensional flow field analysis and flow resistance calculation of the hydraulic deceleration cylinder, the kinematics and dynamics model of the control rod, is built whose results are compared and validated by the CRHDS scram test results under room temperature. Then the model takes into account of the influence of the fuel assembly box on the control rod scram process under high temperature working conditions, and is used to analyze the influence of the key parameters, including the helical spring stiffness inside the deceleration cylinder and the working temperature on the CRHDD working performance. The research results can give guidance for the design and optimization of the CRHDD.

Numerical Research on FPSOs With Green Water Occurrence

2009 ◽  
Vol 53 (01) ◽  
pp. 7-18
Author(s):  
Renchuan Zhu ◽  
Guoping Miao ◽  
Zhaowei Lin
Keyword(s):  
Three Dimensional ◽  
Green Water ◽  
Floating Body ◽  
Incoming Wave ◽  
Model Case ◽  
Floating Structures ◽  
Design And Optimization ◽  
Head Waves ◽  
Wave Heights ◽  
The Impact

Green water loads on sailing ships or floating structures occur when an incoming wave significantly exceeds freeboard and water runs onto the deck. In this paper, numerical programs developed based on the platform of the commercial software Fluent were used to numerically model green water occurrence on floating structures exposed to waves. The phenomena of the fixed floating production, storage, and offloading unit (FPSO) model and oscillating vessels in head waves have been simulated and analyzed. For the oscillating floating body case, a combination idea is presented in which the motions of the FPSO are calculated by the potential theory in advance and computional fluid dynamics (CFD) tools are used to investigate the details of green water. A technique of dynamic mesh is introduced in a numerical wave tank to simulate the green water occurrence on the oscillating vessels in waves. Numerical results agree well with the corresponding experimental results regarding the wave heights on deck and green water impact loads; the two-dimensional fixed FPSO model case conducted by Greco (2001), and the three-dimensional oscillating vessel cases by Buchner (2002), respectively. The research presented here indicates that the present numerical scheme and method can be used to actually simulate the phenomenon of green water on deck, and to predict and analyze the impact forces on floating structures due to green water. This can be of great significance in further guiding ship design and optimization, especially in the strength design of ship bows.

Analysis of Flow Resistance Influence on Step-Down Process of the Control Rod Hydraulic Drive System

2021 ◽  
Author(s):  
Linqing Yang ◽  
Benke Qin ◽  
Hanliang Bo
Keyword(s):  
Theoretical Model ◽  
Flow Resistance ◽  
Inflection Point ◽  
Great Influence ◽  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Drive System ◽  
Pressure Curve ◽  
Control Rod ◽  
Step Down

Abstract Control rod hydraulic drive system (CRHDS) is a new type of built-in control rod drive technology which is invented by INET, Tsinghua University. The integrated valve (IV) is the main flow control component of the CRHDS. Flow resistance of IV has a great influence on the control rod dynamic step-down process. The step-down performance experiments of CRHDS with different flow resistance of IV were conducted under room temperature conditions. Meanwhile, the theoretical model of hydraulic cylinder step-down process was established and combined with the relationship of the flow resistance of IV under the experimental conditions to get the dynamic response of the hydraulic cylinder. The calculation results of theoretical model agree well with the experimental data. On this basis, the theoretical model of hydraulic cylinder step-down process was applied to the high temperature working conditions with different flow resistance of IV. The analysis results show that at higher working temperature, with the increase of the flow resistance of IV control rod step-down average velocity decreases and step-down time increases correspondingly. There is an inflection point in the transient pressure curve and the pressure of the inflection point decreases gradually with the increase of the flow resistance. The pressure lag time after step-down also decreases. The research results lay the base for the design and optimization of the flow resistance of the IV for the CRHDS.

Experimental Study of Motion-Resistance Force of Hydraulic Cylinder of CRHDM

2018 ◽  
Author(s):  
Qianfeng Liu ◽  
Yuzheng Li ◽  
Huang Zhang ◽  
Bo Hanliang
Keyword(s):  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Resistance Force ◽  
Coupling Scheme ◽  
Seal Ring ◽  
Hydraulic Control ◽  
Control Rod ◽  
Design And Optimization ◽  
Motion Resistance ◽  
New Energy

Hydraulic control rod drive technology (HCRDT) is a newly invented patent owned by Institute of Nuclear and New Energy Technology of Tsinghua University with independent intellectual property rights. Hydraulic cylinder is the core part of this technology, so the seal of hydraulic cylinder directly affects the performance of the hydraulic cylinder and HCRDT. A new experiment table was designed and used to study the leakage and internal cylinder friction at various types of friction coupling between internal cylinder and seal ring. The result shows that Motion-Resistance Force is the smallest when the internal cylinder film is TiN. Furthermore, when seal ring film is DLC (Diamond-like carbon) the leakage is the smallest. At last, the best friction coupling scheme was obtained. The experimental results provide the basis for the establishment of the motion model of hydraulic cylinder, which provides a foundation for further design and optimization of hydraulic drive technology of control rod.

Optimized Shroud Design for Axial Turbine Aerodynamic Performance

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
L. Porreca ◽  
A. I. Kalfas ◽  
R. S. Abhari
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Aerodynamic Performance ◽  
Field Analysis ◽  
Test Cases ◽  
Axial Turbine ◽  
Significant Difference ◽  
Flow Field Analysis ◽  
The Impact ◽  
Partial Shroud

This paper presents a comprehensive study of the effect of shroud design in axial turbine aerodynamics. Experimental measurements and numerical simulations have been conducted on three different test cases with identical blade geometry and tip clearances but different shroud designs. The first and second test cases are representative of a full shroud and a nonaxisymmetric partial shroud geometry while the third test case uses an optimized partial shroud. Partial shrouds are sometimes used in industrial application in order to benefit from the advantage of shrouded configuration, as well as reduce mechanical stress on the blades. However, the optimal compromise between mechanical considerations and aerodynamic performances is still an open issue due to the resulting highly three-dimensional unsteady flow field. Aerodynamic performance is measured in a low-speed axial turbine facility and shows that there are clear differences between the test cases. In addition, steady and time resolved measurements are performed together with computational analysis in order to improve the understanding of the effect of the shroud geometry on the flow field and to quantify the sources of the resultant additional losses. The flow field analysis shows that the effect of the shroud geometry is significant from 60% blade height span to the tip. Tip leakage vortex in the first rotor is originated in the partial shroud test cases while the full shroud case presents only a weak indigenous tip passage vortex. This results in a significant difference in the secondary flow development in the following second stator with associated losses that varies by about 1% in this row. The analysis shows that the modified partial shroud design has improved considerably the aerodynamic efficiency by about 0.6% by keeping almost unchanged the overall weight of this component, and thus blade root stresses. The work, therefore, presents a comprehensive flow field analysis and shows the impact of the shroud geometry in the aerodynamic performance.

Analysis of a CRDM Nozzle Break LOCA Without Scram Using the U.S. NRC Coupled Code TRAC-M/PARCS

2002 ◽  
Author(s):  
A. Cuadra ◽  
J. Ragusa ◽  
T. Downar ◽  
K. Ivanov
Keyword(s):  
Nuclear Power ◽  
Cold Water ◽  
Three Dimensional ◽  
Control Rod ◽  
Operation Conditions ◽  
Wide Range ◽  
Core Conditions ◽  
The Impact ◽  
Power Response ◽  
The U.S

Recently, through-wall circumferential cracks in several control rod drive mechanism (CRDM) nozzle penetrations were detected at the Oconee-3 nuclear power plant. The presence of these cracks was seen as a potential precursor to a small break loss of coolant accident. In order to assess the impact of a postulated failure of a CRDM housing, analyses were performed using the U.S. NRC coupled thermal-hydraulics and neutronics code TRAC-M/PARCS. Although deemed highly unlikely, it was assumed that no control rods inserted in order to bound any possible reactivity transient associated with the break. The thermal-hydraulic model used to perform the study is based on an existing model of Oconee, built for PTS analysis, which models the whole plant and some of its control systems. A refined vessel model based on a TMI model was used to increase the resolution of the results and facilitate coupling to PARCS. All relevant ECCS systems were modeled and the control system allowed for, in addition to automatic actions, some assumed operator intervention. In particular, HPI throttling was modeled to maintain the hot leg subcooled at 42 +/- 7 K, and prevent an excessive amount of cold water from being injected into the system. A spatial kinetics analysis of this event was necessary because of the wide range of core conditions which occurred during the transient, from hot full power operation conditions to the cold zero power shutdown state. Analysis of the event with point kinetics and “best estimate” reactivity coefficients resulted in significant miss-prediction of the core power response. Conversely, the three-dimensional kinetics solution with cross section data generated over the entire range of the event led to a more accurate calculation of the power response and the overall analysis of the system transient response. This paper will describe the analysis of the control rod drive nozzle break event without scram using TRAC-M/PARCS.

Three Dimensional Design and Optimization of a Transonic Rotor in Axial Flow Compressors

2011 ◽  
Author(s):  
Hidetaka Okui ◽  
Tom Verstraete ◽  
R. A. Van den Braembussche ◽  
Zuheyr Alsalihi
Keyword(s):  
Three Dimensional ◽  
Axial Flow ◽  
Design Parameters ◽  
Negative Effects ◽  
Stall Margin ◽  
Design And Optimization ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Differential Evolutionary Algorithm ◽  
The Impact

This paper presents a 3-D optimization of a moderately loaded transonic compressor rotor by means of a multi-objective optimization system. The latter makes use of a Differential Evolutionary Algorithm in combination with an Artificial Neural Network and a 3D Navier-Stokes solver. Operating it on a cluster of 30 processors enabled the optimization of a large design space composed of the tip camber line and spanwise distribution of sweep and chord length. Objectives were an increase of efficiency at unchanged stall margin by controlling the shock waves and off-design performance curve. First, tests on a single blade row allowed a better understanding of the impact of the different design parameters. Forward sweep with unchanged camber improved the peak efficiency by only 0.3% with a small increase of the stall margin. Backward sweep with an optimized S shaped camber line improved the efficiency by 0.6% with unchanged stall margin. It is explained how the camber line control could introduce the forward sweep effect and compensate the negative effects of the backward sweep. The best results (0.7% increase in efficiency and unchanged stall margin) have been obtained by a stage optimization that also considered the spanwise redistribution of the rotor flow and loading to reduce the Mach number at the stator hub.

Experimental and Numerical Analysis of the Flow Field in the Integrated Valve for the Control Rod Hydraulic Drive System

2018 ◽  
Author(s):  
Jiang Junfei ◽  
Qin Benke ◽  
Bo Hanliang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Flow Resistance ◽  
Hydraulic Drive ◽  
Flow Channel ◽  
Drive System ◽  
Total Flow ◽  
Control Rod ◽  
Research Results ◽  
Flow Channels

Control Rod Hydraulic Drive System (CRHDS) is a new type of built-in control rod drive technology, and the Integrated Valve (IV) is the key control component of it. The pulse water flowing into the control rod hydraulic mechanism (CRHDM) is controlled by the IV to drive the hydraulic cylinders to move in a predefined sequence to make the control rod perform step-up, step-down and scram functions. Flow resistance of the IV flow channels is the key design parameter of IV which influences the step motion of the hydraulic cylinder and thus affects the performance of the CRHDS. Experiments on the flow resistance of IV flow channels at different working temperatures were conducted to obtain differential pressures of IV under various temperature and flow rate operating conditions. Based on the experimental conditions and results, three dimensional flow field analysis of the IV flow channels was carried out to get the flow field distribution and hydraulic parameters of the IV flow channels. Flow resistance of the IV flow channels at different working temperatures were obtained using the calculation results and agree well with the experimental results. It verified the correctness of the CFD model. On the basis of the numerical simulation results, the velocity and pressure distribution schemes in the IV flow channels under different working temperature conditions were compared and analyzed. The research results show that the flow resistance of the IV in-rod flow channels remains largely unchanged at different working temperatures, the peak flow velocity appears at the entrance of the valve core section which is also the main flow resistance loss area. The theoretical model was then applied to analyze the influence of the design parameters which include the valve core size, the angle between flow channels, etc., on the total flow resistance of IV at high temperatures. And the analysis results show that, the angle between flow channels has little influence on the flow resistance coefficient. The increase of valve core radius can significantly reduce the total flow resistance of IV flow channels. Numerical simulation on one out-rod flow channel is also carried out, which shows that the flow resistance in out-rod flow channel is much lower than the corresponding in-rod flow channels. The research results can give guidance for the design and optimization of the IV.

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