Effect of Adjusting Balance Hole to Cavitation Area on Cavitation Performance of a Centrifugal Pump

2021 ◽  
Vol 14 (3) ◽  
pp. 289-299
Author(s):  
Wang Dongwei ◽  
Liu Zailun ◽  
Han Wei ◽  
Fu You
Keyword(s):  
Centrifugal Pump ◽  
Cavitation Performance

Theory and application of two-dimension viscous hydraulic design of the ultra-low specific-speed centrifugal pump

2019 ◽  
Vol 234 (1) ◽  
pp. 58-71 ◽  
Author(s):  
Cong Wang ◽  
Yongxue Zhang ◽  
Hucan Hou ◽  
Zhiyi Yuan
Keyword(s):  
Boundary Layer ◽  
Centrifugal Pump ◽  
Diagnostic Model ◽  
Two Dimension ◽  
Cavitation Performance ◽  
Hydraulic Design ◽  
Displacement Thickness ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Low Efficiency

Low efficiency and bad cavitation performance restrict the development of the ultra-low specific-speed centrifugal pump (ULSSCP). In this research, combined turbulent boundary layer theory with two-dimension design and two-dimension viscous hydraulic design method has been proposed to redesign a ULSSCP. Through the solution of the displacement thickness in the boundary layer, a less curved blade profile with a larger outlet angle was obtained. Then the hydraulic and cavitation performance of the reference pump and the designed pump were numerically studied. The comparison of performance of the reference pump calculated by the numerical and experimental results revealed a better agreement. Research shows that the average hydraulic efficiency and head of the designed pump improve by 2.9% and 3.3%, respectively. Besides, the designed pump has a better cavitation performance. Finally, through the internal flow analysis with entropy production diagnostic model, a 24.8% drop in head loss occurred in the designed pump.

scholarly journals Influence of wall roughness on cavitation performance of centrifugal pump

2021 ◽  
Vol 43 (6) ◽  
Author(s):  
Weihui Xu ◽  
Xiaoke He ◽  
Xiao Hou ◽  
Zhihao Huang ◽  
Weishu Wang
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Internal Flow ◽  
Wall Roughness ◽  
Blade Surface ◽  
Centrifugal Pumps ◽  
Three Dimensional Model ◽  
Cavitation Inception ◽  
Cavitation Performance ◽  
Critical Cavitation

AbstractCavitation is a phenomenon that occurs easily during rotation of fluid machinery and can decrease the performance of a pump, thereby resulting in damage to flow passage components. To study the influence of wall roughness on the cavitation performance of a centrifugal pump, a three-dimensional model of internal flow field of a centrifugal pump was constructed and a numerical simulation of cavitation in the flow field was conducted with ANSYS CFX software based on the Reynolds normalization group k-epsilon turbulence model and Zwart cavitation model. The cavitation can be further divided into four stages: cavitation inception, cavitation development, critical cavitation, and fracture cavitation. Influencing laws of wall roughness of the blade surface on the cavitation performance of a centrifugal pump were analyzed. Research results demonstrate that in the design process of centrifugal pumps, decreasing the wall roughness appropriately during the cavitation development and critical cavitation is important to effectively improve the cavitation performance of pumps. Moreover, a number of nucleation sites on the blade surface increase with the increase in wall roughness, thereby expanding the low-pressure area of the blade. Research conclusions can provide theoretical references to improve cavitation performance and optimize the structural design of the pump.

Cavitation performance of high-speed centrifugal pump with annular jet and inducer at different temperatures and void fractions

2019 ◽  
Vol 31 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Jin Jiang ◽  
Yan-hui Li ◽  
Chong-yan Pei ◽  
Lin-lin Li ◽  
You Fu ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
High Speed ◽  
Void Fractions ◽  
Cavitation Performance ◽  
Annular Jet ◽  
Different Temperatures

scholarly journals Detection of Inception Cavitation in Centrifugal Pump by Fluid-Borne Noise Diagnostic

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Liang Dong ◽  
Yuqi Zhao ◽  
Cui Dai
Keyword(s):  
Centrifugal Pump ◽  
Detection Threshold ◽  
High Sensitivity ◽  
Pressure Level ◽  
Experimental Methodology ◽  
Detection Methods ◽  
Cavitation Inception ◽  
Cavitation Performance ◽  
Pattern Distribution ◽  
Cavitation Detection

This paper presents an experimental methodology that is capable of sensitively detecting the cavitation inception in a centrifugal pump. Firstly, with a centrifugal pump of ns=117 as research object, the cavitation performance, the bubble pattern distribution at impeller inlet, and the vibration and noise were synchronously measured at different flow conditions each with several cavitation coefficients. The change laws of total level of vibration and noise signals throughout the cavitation process were emphatically investigated. After comparing the sensitivity and reliability of different detection methods, the method based on overall sound pressure level of liquid-borne noise is found to present high sensitivity to cavitation. Secondly, by comparing the affected 1/3 octave spectrum by changing flow and cavitation coefficients, the highly sensitive frequency band to cavitation was obtained. Then, a new inception cavitation detection method was proposed based on Pauta principle. Finally, the method was verified through an ultra-low-specific speed pump (ns=25). The results show that the total pressure level of liquid-borne noise increases firstly and then decreases with the development of cavitation. The broadband SPL of liquid-borne noise between 2000 and 3000 Hz can be used to detect the inception cavitation, and the cavitation detection threshold is determined as 1.0%.

The Rotating Cavitation Performance of a Centrifugal Pump with a Splitter-Bladed Inducer under Different Rotational Speed

2015 ◽  
Vol 32 (3) ◽  
Author(s):  
XiaoMei Guo ◽  
ZuChao Zhu ◽  
BaoLing Cui ◽  
Yi Li
Keyword(s):  
Centrifugal Pump ◽  
Rotational Speed ◽  
High Speed ◽  
Internal Flow ◽  
Centrifugal Pumps ◽  
Cavitation Flow ◽  
Operation Condition ◽  
Cavitation Performance ◽  
Cavitation Behavior ◽  
Suction Performance

AbstractDesigning inducer is one of the effective ways to improve the suction performance of high-speed centrifugal pumps. The operation condition including rotational speeds can affect the internal flow and external performance of high-speed centrifugal pumps with an inducer. In order to clarify the rotating cavitation performance of a centrifugal pump with a splitter-bladed inducer under different rotational speed, a centrifugal pump with a splitter-bladed inducer is investigated in the work. By using Rayleigh–Plesset equations and Mixture model, the cavitation flow of centrifugal pump is numerically simulated, as well as the external performance experimental test is carried out. It is found that the cavitation area increases with the rotational speeds. The location of the passage where cavitation is easy to appear is explored. Asymmetric cavitation behavior is observed. That, the trail of the inducer is easy to take cavitation when the rotational speed is increased to a degree, is also observed. The trend of

Comparative Study on Hydraulic Performance of Single-Suction Centrifugal Pump and Double-Suction Centrifugal Pump

2017 ◽  
Author(s):  
Chaoyue Wang ◽  
Fujun Wang ◽  
Zhichao Zou
Keyword(s):  
Centrifugal Pump ◽  
Pressure Fluctuation ◽  
Hydraulic Performance ◽  
Wake Structure ◽  
Suction Pump ◽  
Cavitation Performance ◽  
Impeller Outlet ◽  
Quantitative Results ◽  
Design And Manufacture ◽  
External Characteristics

In engineering applications, design and manufacture of double-suction impeller are on the basis of single-suction impeller. However, there is a lack of clear view on the differences of hydraulic performance between single-suction centrifugal pump and double-suction centrifugal pump which has the same blades. In this paper, a single-suction centrifugal pump and double-suction centrifugal pump with the same blades are investigated respectively, and their hydraulic performances have been compared in terms of external characteristics, flow pattern, pressure fluctuation and cavitation characteristics. In operating range of 0.6Q0∼1.1Q0, results show that the efficiency of double-suction pump is 4.14% higher than that of single-suction pump stably, and the head of single suction pump is 3.5% higher than that of double-suction pump stably. Single-suction impeller and double-suction impeller have similar jet-wake structure in impeller outlet, but the amplitude of velocity of single suction impeller changes more sharply. In the vicinity of rated condition, the amplitude of pressure fluctuation of double suction pump is about half that of the single suction pump, and the cavitation performance of double suction pump and single suction pump are basically the same. These quantitative results show that pressure fluctuation characteristics and cavitation performance of single-suction pump and double-suction pump with the same blades have little difference in the vicinity of rated condition. Compared with single-suction pump, the head of double-suction pump has declined, while the efficiency has improved remarkably. The research results have significant guidance on excavating the potential of excellent hydraulic models and guiding the design of double-inlet multistage double-suction centrifugal pump.

Thermodynamic Effect and Cavitation Performance of a Cavitating Centrifugal Pump

2011 ◽  
Author(s):  
Teiichi Tanaka
Keyword(s):  
Centrifugal Pump ◽  
Liquid Nitrogen ◽  
Cold Water ◽  
Experimental Results ◽  
Flow Coefficient ◽  
Test Setup ◽  
Cavitation Performance ◽  
Thermodynamic Effect ◽  
Delivery Pressure ◽  
Temperature Depression

The thermodynamic effect which affects the cavitation performance of a cavitating centrifugal pump was investigated experimentally using liquid nitrogen. To measure the pump cavitation performance, a test setup which could carry out experiments using both liquid nitrogen and cold water was constructed. The test setup consisted of a suction tank, a test pump, a mass flow meter, a ball valve and pipes. Vacuum-insulated pipes were used. The test pump was a centrifugal type magnetic pump, and two impellers, which differed in cavitation performance, were used in experiments. Cavitation performance using liquid nitrogen or cold water could be obtained from the measurement of the pump suction and delivery pressure, the pump suction and delivery temperature, and the discharge flow rate. And an improvement in pump cavitation performance could be seen when comparing the experimental results from using liquid nitrogen with those from using cold water. The experimental results indicated that cavitation performance using liquid nitrogen was better than that using cold water. This improvement in cavitation performance was thought to be due to the thermodynamic effect of cavitation. And the estimated temperature depression due to the thermodynamic effect decreased with a decreasing flow coefficient. Moreover, it was shown that the estimated temperature depression due to the thermodynamic effect on the low cavitation performance impeller was larger than that on the high cavitation performance impeller at the same flow coefficient.

scholarly journals Influence of the Balance Hole Circumferential Position on the Cavitation Performance of the Semiopen Impeller Centrifugal Pump

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xiaorui Cheng ◽  
Jiaheng Luo ◽  
Bo Xiong ◽  
Yimeng Jiang
Keyword(s):  
Centrifugal Pump ◽  
Axial Force ◽  
Cavitation Bubble ◽  
Bubble Dynamics ◽  
Leading Edge ◽  
The Other ◽  
Cavitation Performance ◽  
Working Surface ◽  
Low Specific Speed ◽  
Specific Speed

In order to study the influence of the circumferential position of the balance hole on the cavitation performance of the semiopen impeller centrifugal pump, a low specific speed semiopen impeller centrifugal pump is taken as the object, and 4 kinds of circumferential positions of balance holes are designed. The SST k-ω turbulence model and the Rayleigh–Plesset cavitation bubble dynamics equation are used to calculate the full flow field of the centrifugal pump. Research shows that, under cavitation conditions, as the circumferential position of the balance hole is farther away from the blade working surface, the cavitation performance of the pump is reduced, and the larger θ (the angle of the balance hole and the leading edge of the blade in the direction of rotation) is, the easier the jet cavitation occurs near the balance hole. On the other hand, with the development of cavitation, the axial force of the impeller has also changed greatly. In contrast, the farther the balance hole is arranged in the circumferential direction (i.e., the greater θ), the more limited is the ability of the balance hole to balance the axial force.

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