Effects of Sleeve Parameters On Cavitation Control Performance in Steam Trap Valves

2021 ◽  
Author(s):  
Chang Qiu ◽  
Zhi-xin Gao ◽  
Zhi-jiang Jin ◽  
Jin-yuan Qian
Keyword(s):  
Power Systems ◽  
Optimization Design ◽  
Thermal Power ◽  
Orifice Diameter ◽  
Geometrical Parameters ◽  
Piping System ◽  
Cavitation Performance ◽  
Installation Angle ◽  
Steam Trap ◽  
Cavitation Intensity

Abstract The steam trap valve is used in thermal power systems to pour out condensate water and keep steam inside. While flowing through steam trap valves, the condensate water can easily reach cavitation, which may cause serious damage to the piping system. In this paper, in order to control cavitation inside steam trap valves, effects of sleeve parameters, including orifice diameter, installation angle and thickness, are investigated using a cavitation model. The pressure, velocity and vapor distribution inside valves are analyzed and compared for different sleeve geometrical parameters. The total vapor volumes are also predicted and compared. The results show that the sleeve parameters have a significant influence on the cavitation intensity and cavitation vapor distributions. Specifically, the orifice diameter of the sleeve has much larger effect on each aspect than that of other two geometrical parameters of the sleeve. The improved geometrical parameters of the sleeve are determined to suppress the cavitation inside the valve. The sleeve with smaller diameter orifices, higher installation angle (maximum 80°) and higher thickness is recommended in practice for better anti-cavitation performance. The work is of significance for cavitation control and the optimization design of steam trap valves.

An Optimization Study on Cavitation Flow in a Steam Trap Valve

2019 ◽  
Author(s):  
Chang Qiu ◽  
Han Zhang ◽  
Chen Yang ◽  
Cong-wei Hou ◽  
Zhi-jiang Jin ◽  
...  
Keyword(s):  
Power Systems ◽  
Working Condition ◽  
Pressure Field ◽  
Volume Fraction ◽  
Thermal Power ◽  
Maximum Flow ◽  
Piping System ◽  
Inner Pressure ◽  
Steam Trap ◽  
Optimization Study

Abstract Steam trap valves are mainly used in thermal power systems to pour out condensate water and keep steam inside. While during the condensate water flowing through steam trap valves, the condensate water is easy to reaching cavitation, which may cause serious damage to the piping system. In order to reducing the cavitation occupation in steam trap valves, this paper mainly deals with an optimization study. With Computational Fluid Dynamics codes, numerical model of a typical steam trap valve is established with Mixture model. The inner pressure field, flow field and steam volume fraction are all achieved under both maximum flow rate working condition and regular working condition. Based on the cavitation results, the throttling stages of the steam trap valve are optimized. And the results show that cavitation range inside the steam trap valve is reduced.

A Parametric Study of Hydrodynamic Cavitation Inside Globe Valves

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Zhi-jiang Jin ◽  
Zhi-xin Gao ◽  
Jin-yuan Qian ◽  
Zan Wu ◽  
Bengt Sunden
Keyword(s):  
Large Deviation ◽  
Fluid Velocity ◽  
Economic Loss ◽  
Hydrodynamic Cavitation ◽  
Geometrical Parameters ◽  
Piping System ◽  
Valve Body ◽  
Cavitation Intensity ◽  
Bending Radius ◽  
Globe Valve

Hydrodynamic cavitation that occurs inside valves not only increases the energy consumption burden of the whole piping system but also leads to severe damages to the valve body and the piping system with a large economic loss. In this paper, in order to reduce the hydrodynamic cavitation inside globe valves, effects of valve body geometrical parameters including bending radius, deviation distance, and arc curvature linked to in/export parts on hydrodynamic cavitation are investigated by using a cavitation model. To begin with, the numerical model is compared with similar works to check its accuracy. Then, the cavitation index and the total vapor volume are predicted. The results show that vapor primarily appears around the valve seat and connecting downstream pipes. The hydrodynamic cavitation does not occur under a small inlet velocity, a large bending radius, and a large deviation distance. Cavitation intensity decreases with the increase of the bending radius, the deviation distance, and the arc curvature linked to in/export parts. This indicates that valve geometrical parameters should be chosen as large as possible, while the maximal fluid velocity should be limited. This work is of significance for hydrodynamic cavitation or globe valve design.

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

Supercritical Carbon Dioxide Brayton Cycles Driven by Solar Thermal Power Tower System

2015 ◽  
Vol 1116 ◽  
pp. 94-129 ◽  
Author(s):  
Maimoon Atif ◽  
Fahad A. Al-Sulaiman
Keyword(s):  
Carbon Dioxide ◽  
Mathematical Model ◽  
Power Systems ◽  
Solar Power ◽  
Current Model ◽  
Thermal Power ◽  
Solar Thermal ◽  
Solar Thermal Power ◽  
Thermal Energy Storage Systems ◽  
Tower System

This chapter starts with a background about concentrating solar power systems and thermal energy storage systems and then a detailed literature review about concentrated solar power systems and supercritical Brayton carbon dioxide cycles. Next, a mathematical model was developed and presented which generates and optimizes a heliostat field effectively. This model was developed to demonstrate the optimization of a heliostat field using differential evolution, which is an evolutionary algorithm. The current model illustrates how to employ the developed model and its advantages. The optimization process calculates the optical performance parameters at every step of the optimization considering all the heliostats; thus yields accurate results as discussed in this chapter. On the other hand, complete mathematical model of supercritical CO2Brayton cycles when integrated with solar thermal power tower system was presented and discussed.

Significance of educational modeling during the COVID-19 coronavirus pandemic

2020 ◽  
pp. 57-64
Author(s):  
E.V. Karpovich
Keyword(s):  
Computer Simulation ◽  
Power Systems ◽  
Thermal Power ◽  
Educational Process ◽  
Quality Education ◽  
High Quality ◽  
High Quality Education ◽  
Distant Learning ◽  
Automation Systems ◽  
Detailed Presentation

The article shows computer simulation of the mechanical, thermal power systems and electronics and automation systems for the modern educational process organized remotely during the COVID-19 coronavirus pandemic. The article describes the computer models made by the author, analyzes and highlights the positive aspects of such simulation for conducting distant learning experiments, visual and detailed presentation of theoretical material and making conditions for obtaining high-quality education even under difficult pandemic conditions.

Optimization of a vacuum cleaner fan suction and shaft power using Kriging surrogate model and MIGA

2021 ◽  
pp. 095765092110496
Author(s):  
Soheil Almasi ◽  
Mohammad Mahdi Ghorani ◽  
Mohammad Hadi Sotoude Haghighi ◽  
Seyed Mohammad Mirghavami ◽  
Alireza Riasi
Keyword(s):  
Optimization Design ◽  
Optimization Technique ◽  
Internal Flow ◽  
Latin Hypercube Sampling ◽  
Sample Space ◽  
Geometrical Parameters ◽  
Vacuum Cleaner ◽  
Time Saving ◽  
Design Variables ◽  
Shaft Power

Optimization of vacuum cleaner fan components is a low-cost and time-saving solution to satisfy the increasing requirement for compact energy-efficient cleaners. In this study, surrogate-based optimization technique is used and for the first time it is focused on maximization of Airwatt parameter, which describes the fan suction power, as an objective function (Case II). Besides, the shaft power is minimized (Case I) as another optimization target in order to reduce the power consumption of the vacuum cleaner. 11 geometrical variables of 3 fan components including impeller, diffuser and return channel are selected as the optimization design variables. 80 training points are distributed in the sample space using Advanced Latin Hypercube Sampling (ALHS) technique and the outputs of sample points are calculated by means of CFD simulations. Kriging and RSA surrogate models have been fitted to the outputs of the sample space. Through coupling of constructed Kriging models and Multi-Island Genetic Algorithm (MIGA), the optimal design for each of the optimization cases is presented and evaluated using numerical simulations. A 20.22% reduction in shaft power in Case I and an improvement of 27.73% in Airwatt in Case II have been achieved as the overall results of this study. Despite achieving goals in both optimization cases, a slight decrease in Airwatt in Case I (−6.20%) and a slight increase in shaft power in Case II (+4.82%) are observed relative to primary fan. Furthermore, the Analysis of Variance (ANOVA) determines the importance level of design variables and their 2-way interactions on the objective functions. It was concluded that geometrical parameters related to all of the fan components must be considered simultaneously to conduct a comprehensive optimization. The reasons of enhancement in optimal cases compared with the reference design have been further investigated by analysis of the fan internal flow field. Post-processing of the CFD results demonstrates that the applied geometrical modifications cause a more uniform flow through the flow passages of the optimal fan components.

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