Inlet Passage’s Development and Optimization of New Tidal Unit-Shaft Tubular Turbine

2014 ◽  
Vol 607 ◽  
pp. 312-316
Author(s):  
Chun Xia Yang ◽  
Meng Tian Lu ◽  
Yuan Zheng ◽  
Xiao Qing Tian ◽  
Yu Quan Zhang
Keyword(s):  
Flow Rate ◽  
High Efficiency ◽  
Guide Vane ◽  
Simulation Software ◽  
Hydraulic Loss ◽  
Vertical Shaft ◽  
Tidal Power ◽  
Large Power ◽  
Flow Passage ◽  
Water Head

A new type of tidal unit-vertical shaft tubular turbine is designed with high efficiency, large flow rate and low water head ,which has large power under the 2~3 meters water head. According to the data of the being installed tidal units and principles of tubular turbine’s design, the high efficiency vertical shaft tubular turbine was designed under large discharge and low head, which was suitable for the tidal power station. The design also considered the requirements of turbine’s size and the details of flow through the whole flow passage were attained. The turbine’s property was predicted by the 3-d numerical simulation software on the whole flow passage. Moreover, the influences of vertical shaft’s sizes were analyzed. And the terminal of vertical shaft with or without transverse brace and longitudinal brace were analyzed to get the influence. Considering the hydraulic performance of various methods, the best guide vane opening was chosen. The results show that, the turbine unit has the best performance on efficiency, hydraulic loss, etc. with the guide vane opening 62°, meeting the power station’s design requirements. The results show that the optimal designed flow passage’s efficiency reaches up to 88.4%, the flow rate becomes much larger and the power reaches 174.63kW. Without partial vortex, the flow pattern is smooth through the whole passage also with lower hydraulic loss.

Analysis of the Influence of Passage Components on the Efficiency of Bulb Tubular Pumps

2008 ◽  
Author(s):  
Yan Jin ◽  
Chao Liu ◽  
Fangping Tang ◽  
Jiren Zhou ◽  
Li Cheng
Keyword(s):  
High Efficiency ◽  
Guide Vane ◽  
Low Cost ◽  
Flow Characteristics ◽  
Simple Algorithm ◽  
Water Diversion ◽  
Hydraulic Loss ◽  
Flow Passage ◽  
Pump Stations ◽  
Large Discharge

For large discharge and low lift head, it is especially suitable to use tubular pumps for their economic characteristics. Tubular pumps have high efficiency, small hydraulic loss, compact unit structure, simple construction arrangement and low cost both for construction and running. Recently, in the east route of South to North Water Diversion Project in China, there are many low head and large discharge pump stations using tubular pumps. It is important to analyze the flow characteristics and performance of tubular pump. In this paper CFD method is used to simulate the whole flow passage in a bulb tubular pump which includes inlet passage, outlet passage, guide vane, bulb unit and supportings. Based on the RNG k–ε turbulent model with Wall-Function Law, the SIMPLE algorithm is applied for the solution of the discrete governing equations. The results of the calculation indicate that all of the flow passage components influence the efficiency of the tubular pump, especially the parts of guide vane unit and bulb section. The shape of the bulb and relative position of guide vanes and bulb supportings have important effects on total hydraulic losses of the pump. Reasonable supportings not only improve the turbulent flow, but also reduce circumference velocity. The efficiency of the pump after improving can be increased about 6%.

Hydraulic Design of Inlet Guide Vane and its Full Flow Passage Numerical Simulation on Centrifugal Pump

2014 ◽  
Author(s):  
Hucan Hou ◽  
Yongxue Zhang ◽  
Zhenlin Li ◽  
Xin Zhou ◽  
Zizhe Wang
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Guide Vane ◽  
Hydraulic Performance ◽  
Design Flow ◽  
Inlet Guide Vane ◽  
Hydraulic Efficiency ◽  
Flow Passage ◽  
Setting Angle ◽  
Hydraulic Design

In order to effectively improve hydraulic performance of centrifugal pump on off-conditions, the hydraulic design of inlet guide vane (IGV) was completed by adopting two dimensional theory in-house code based on one kind of IS series of centrifugal pump, which can achieve pre-whirl regulation of centrifugal pump. During design process the trailing edge of vane is assumed as equal velocity moment condition, and the distribution of vane setting angle along meridional streamline is also given as a quartic function firstly, the camber line is then drawn by point-by-point integration method and thickened at both sides along circumferential direction. With local vortex dynamics diagnosis theory, the optimal improvement of vane space shape can be finished by adjusting the design parameters of vane setting angle distribution coefficient ap. The full flow passage numerical simulations of centrifugal pump with IGV device are completed to analyze the influence of pre-whirl regulation on hydraulic performance of centrifugal pump under various pre-whirl angles. The results show that the pre-whirl regulation can improve the hydraulic performance of centrifugal pump on off-conditions. Under the positive pre-whirl regulation conditions, the best efficient point shift to small flow rate zone, and under the negative pre-whirl regulation conditions it moves to large flow rate zone. Compared with the pump without IGV device at the same flow rate condition of 0.8Q (Q the design flow rate), the hydraulic efficiency of centrifugal pump with IGV device improves obviously and reaches up to 1.43%. Meanwhile compared with that installed with the straight vanes designed based on the traditional theory, the inner flow field of centrifugal pump with the designed vanes improves and the overall hydraulic efficiency of centrifugal pump is somewhat increased.

scholarly journals Improvement of the Efficiency of the Axial-Flow Pump at Part Loads due to Installing Outlet Guide Vanes Mechanism

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Fan Yang ◽  
Hao-ru Zhao ◽  
Chao Liu
Keyword(s):  
Prediction Model ◽  
Flow Rate ◽  
High Efficiency ◽  
Guide Vane ◽  
Axial Flow ◽  
Hydraulic Performance ◽  
Operating Conditions ◽  
Ann Model ◽  
Axial Flow Pump ◽  
Flow Pump

In order to investigate the influence of adjustable outlet guide vane on the hydraulic performance of axial-flow pump at part loads, the axial-flow pump with 7 different outlet guide vane adjustable angles was simulated based on the RNG k-ε turbulent model and Reynolds time-averaged equations. The Vector graphs of airfoil flow were analyzed in the different operating conditions for different adjustable angles of guide vane. BP-ANN prediction model was established about the effect of adjustable outlet guide vane on the hydraulic performance of axial-flow pump based on the numerical results. The effectiveness of prediction model was verified by theoretical analysis and numerical simulation. The results show that, with the adjustable angle of guide vane increasing along clockwise, the high efficiency area moves to the large flow rate direction; otherwise, that moves to the small flow rate direction. The internal flow field of guide vane is improved by adjusting angle, and the flow separation of tail and guide vane inlet ledge are decreased or eliminated, so that the hydraulic efficiency of pumping system will be improved. The prediction accuracy of BP-ANN model is 1%, which can meet the requirement of practical engineering.

Effects of Blade Inlet Width on Performance of Centrifugal Pump as Turbine With Special Impeller Using in Turbine Mode

2016 ◽  
Author(s):  
Tao Wang ◽  
Xiaobing Liu ◽  
Xide Lai ◽  
Qiuqin Gou
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
High Efficiency ◽  
Cost Effective ◽  
Pressure Head ◽  
Design Flow ◽  
Hydraulic Loss ◽  
Obvious Effect ◽  
Velocity Moment ◽  
Turbine Mode

A reverse running centrifugal pump is one of the attractive choices in micro-hydropower development and industrial pressure energy recovery. One of the main problems in utilizing pump as turbine (PAT) is that the performance of PAT is usually not ideal due to the impeller with the routine backward curved blades which do not match well with turbine running condition. A cost effective suitable way for solving this problem is to redesign impeller with forward curved blades from turbine working condition while the other components do not undergo any modifications. Blade inlet width is one of the main factors in impeller design. Therefore, research on the influence of blade inlet width on PAT performance is useful. In this paper, based on the constant velocity moment theory, the velocity moment at impeller inlet is acquired, firstly. Next, a relationship expression between blade inlet angle and the design flow rate is deduced. To perform research on blade inlet width influencing PAT’s performance with special impeller, three impellers which inlet widths are 13 mm, 16 mm and 19 mm, respectively, are designed by using ANSYS Bladegen software. Numerical simulation and analysis of the three PATs are performed using a verified computational fluid dynamics (CFD) technique. Comparison of three PATs’ performance curves obtained by CFD, we can find that the blade inlet width has obvious effect on the performance of PAT. The flow rate, required pressure head, generated shaft power, and efficiency at best efficiency point (BEP) increase with the increase of blade inlet width. The flow rates of three PATs at BEP are about 90 m3/h, 100 m3/h and 105 m3/h, respectively, when impeller inlet width varies from 13 mm to 16 mm and 19 mm. The BEP of three PATs shifts towards higher discharge and its high efficiency range becomes wider with the increase of blade inlet width. At above 100 m3/h discharge, the PAT efficiency increases in accordance with the increase of blade inlet width. And the hydraulic loss and turbulence kinetic energy loss within impeller decrease with the increase of blade inlet width. In order to improve efficiency, it is helpful to choose a relatively larger blade inlet width in the design of special impeller using in turbine mode of PAT.

scholarly journals Influence of Inlet Angle of Guide Vane on Hydraulic Performance of an Axial Flow Pump Based on CFD

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Lei Xu ◽  
Dongtao Ji ◽  
Wei Shi ◽  
Bo Xu ◽  
Weigang Lu ◽  
...  
Keyword(s):  
Working Conditions ◽  
Flow Rate ◽  
Guide Vane ◽  
Axial Flow ◽  
Hydraulic Performance ◽  
Hydraulic Loss ◽  
Rate Region ◽  
Axial Flow Pump ◽  
Inlet Angle ◽  
Flow Pump

Axial flow pump has been widely used in hydraulic engineering, agriculture engineering, water supply and sewerage works, and shipbuilding industry. In order to improve the hydraulic performance of pump under off-design working conditions, the influence of the inlet segment axial chord and inlet angle adjustment of the guide vane on the pump segment efficiency and flow filed was simulated by using the renormalization group (RNG) k − ε turbulent model based on the Reynolds-averaged Navier–Stokes equations. The results indicate that the inlet segment axial chord and inlet angle adjustment of guide vane have a strong influence on the pump segment efficiency. Considering the support function and hydraulic loss of the guide vane, the inlet segment axial chord is set to 0.25 times the axial chord of guide vane. On the basis of the inlet angle of the guide vane under design conditions, when the inlet segment angle is turned counterclockwise, the pump segment efficiency is improved in the lower flow rate region; moreover, the pump segment efficiency is improved in the larger flow rate region when the inlet segment angle is turned clockwise. As the conditions deviate from the design working conditions, the influence of the guide vane inlet angle on the pump segment efficiency increases. If the inlet segment angle is properly adjusted under off-design working conditions, the flow pattern in the guide vane is improved and the hydraulic loss is decreased, because the inlet segment angle matches with the flow direction of impeller outlet; consequently, the pump segment efficiency is increased.

scholarly journals Pressure Pulsations of the Blade Region in S-Shaped Shaft-Extension Tubular Pumping System

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Fan Yang ◽  
Chao Liu
Keyword(s):  
Flow Rate ◽  
High Efficiency ◽  
Rotation Speed ◽  
Guide Vane ◽  
Three Dimensional ◽  
Dominant Frequency ◽  
Flow Coefficient ◽  
Pressure Pulsations ◽  
Rate Condition ◽  
Pumping System

The three-dimensional unsteady numerical method is applied to investigate the pressure fluctuation of the S-shaft extension pumping system. Some monitor pointers are set at the key positions of blade region to capture the changing rules of the pressure pulsations, from which the data are collected through time-domain and spectrum analysis. The predicted head and efficiency were validated by the comparison with the tested results, and the comparison result shows that the unsteady flow characteristic of pumping system can be simulated by this method. The pulsating amplitude decreases gradually from blade tip to hub, under the condition of large flow rate for both the inlet and outlet of the impeller, in the way different from the smaller flow rate condition. Through adjusting the impeller rotation speed and the number of blades, the dominant frequency can be controlled. For the same monitor point at the impeller, as the flow coefficient is becoming larger, the pulsating amplitude decreases, in which case, it decreases firstly and then increases between the impeller and the guide vane, and the pulsating amplitude is smallest on the high efficiency condition. The rotation speed of impeller has little effect on the dominant frequency at the outlet of guide vane.

Influence of Guide Vane Shapes on Hydraulic Characteristics for a Shaft-Extension Tubular Pump Turbine at Turbine Mode

2014 ◽  
Author(s):  
Renfang Huang ◽  
Xianwu Luo ◽  
Bin Ji ◽  
Yuan Zheng
Keyword(s):  
High Efficiency ◽  
Guide Vane ◽  
Leading Edge ◽  
Suction Side ◽  
Hydraulic Loss ◽  
Steady Flows ◽  
Pump Turbine ◽  
Guide Vanes ◽  
Section Profile ◽  
Turbine Mode

Guide vanes are important components for a shaft-extension tubular pump turbine. To study the influence of guide vanes on the performance of a shaft-extension tubular pump turbine, three guide vanes with different section profiles are prepared. The steady flows through the whole passage of the shaft-extension tubular pump turbine with different guide vanes are simulated based on RNG k-ε turbulence model. The numerical results show that the section profile of a guide vane influences the hydraulic performance of the pump turbine. It is noted that the pump turbine with the guide vane profile having a large curvature has a broader operation range with high efficiency, and the minimal hydraulic loss among three guide vanes. Further investigation depicts that the static pressure and velocity distribution in the guide vane are relatively uniform, and there are hardly flow incidence at the leading edge and little low pressure zone near the suction side for the suitable guide vane profile.

The Study of Guide Vanes on Submersible Pump

2009 ◽  
Author(s):  
Bin Chen ◽  
Lanjin Zhang ◽  
Kewei Zhang ◽  
Guangjie Peng
Keyword(s):  
Guide Vane ◽  
Meridian Plane ◽  
Hydraulic Loss ◽  
Submersible Pump ◽  
Flow Passage ◽  
Guide Vanes ◽  
Diffusion Loss ◽  
Outlet Angle ◽  
Flow Pump ◽  
Large Diffusion

Because the structure of submersible pump is special, and common guide vane is a factor effecting low efficiency, those guide vanes design method is different from ones of common axial flow pump and mixed flow pump. This paper introduces the design methods of guide vane on submersible pump. To improve the total performance, submersible pump structure, hydraulic performance, diffusion and friction loss are considered comprehensively when the meridian plane of guide vane is designed. The coefficient of diffusion on meridian plane should be larger than the recommended value and limited to avoid heavy flow separation. The guide vane number is bigger and meridian length of guide vane is shortened. For example, the number of guide vane can be nine or eleven, even thirteen when impeller blade number is four. Bigger number of guide vane makes the short guide vane placed on smaller diameter and avoids flow passage diffused more. On the other hand, smaller diameter will decrease pump dimension, weight, and production cost. To Balance the recycled energy and loss energy, outlet angle of guide vane should be reduced suitable. The angle should be 90 degree if completely recycling the rotating flow energy, but outlet angle should be larger than 90 degree if considering finite cascade. Those two angles will bring large diffusion of flow passage, large diffusion loss and flow friction force. Since the diffusion loss counts heavier percent of hydraulic loss, the angle should be reduced, such as 70 degree. That smaller angle doesn’t recycle completely the rotating energy, but hydraulic loss is decreased, and the efficiency of pump is higher instead. The test testifies that the efficiency of submersible pump designed by those above measures can reach 88%.

scholarly journals The Influence of Bulb Position on Hydraulic Performance of Submersible Tubular Pump Device

2021 ◽  
Vol 9 (8) ◽  
pp. 831
Author(s):  
Zhuangzhuang Sun ◽  
Jie Yu ◽  
Fangping Tang
Keyword(s):  
Entropy Production ◽  
Large Scale ◽  
Experimental Testing ◽  
Guide Vane ◽  
Outer Wall ◽  
Hydraulic Performance ◽  
Hydraulic Loss ◽  
Optimized Design ◽  
Outlet Channel ◽  
Wall Area

In order to study the influence of the position of the bulb on the hydraulic performance of asubmersible tubular pump device, based on a large-scale pumping station, two schemes—involving a front-mounted bulb and a rear-mounted bulb, respectively—were designed. The front-mounted scheme uses the GL-2008-03 hydraulic model and its conventional guide vane, while the rearmounted scheme uses the optimized design of a diffuser vane. The method of combining numerical simulation and experimental testing was used to analyze the differences between the external and internal characteristics of the two schemes. The results show that, under the condition of reasonable diffusion guide vane design, the efficiency under the rear-mounted scheme is higher than that under the front-mounted scheme, where the highest efficiency difference is about 1%. Although the frontmounted bulb scheme reduces the hydraulic loss of the bulb section, the placement of the bulb on the water inlet side reduces the flow conditions of the impeller. Affected by the circulation of the guide vane outlet, the hydraulic loss of the outlet channel is greater than the rear-mounted scheme. The bulb plays a rectifying function when the bulb is placed behind, which greatly eliminates the annular volume of the guide vane outlet, and the water outlet channel has a smaller hydraulic loss. In the front-mounted scheme, the water flow inside the outlet channel squeezes to the outer wall, causing higher entropy production near the outer wall area. The entropy production of the rear-mounted scheme is mainly in the bulb section and the bulb support. This research can provide reference for the design and form selection of a submersible tubular pump device, which has great engineering significance.

scholarly journals Numerical and Experimental Analysis of Flow and Pulsation in Hump Section of Siphon Outlet Conduit of Axial Flow Pump Device

2021 ◽  
Vol 11 (11) ◽  
pp. 4941
Author(s):  
Fan Yang ◽  
Yiqi Zhang ◽  
Yao Yuan ◽  
Chao Liu ◽  
Zhongbin Li ◽  
...  
Keyword(s):  
Flow Field ◽  
Flow Rate ◽  
Vortex Structure ◽  
Pressure Fluctuation ◽  
Axial Flow ◽  
Mean Value ◽  
Hydraulic Loss ◽  
Pressure Amplitude ◽  
Measuring Point ◽  
Outlet Conduit

In order to study the variation law of the flow field and pressure fluctuation in the hump section of the siphon outlet conduit, the flow field characteristics and frequency spectrum characteristics of the flow field were analyzed by combining a physical model test and numerical simulation under the conditions of the interaction between the axial flow pump and siphon outlet conduit, and the influence of the residual circulation at the outlet of the guide vane on the siphon outlet flow was investigated. Based on the influence of the flow field and hydraulic loss in the conduit, the equivalent surface method based on the Q criterion was used to analyze the vortex structure in the siphon outlet conduit and to analyze the internal vortex state. The results showed that with the increase of the flow rate, the intensity of the vortices in the cross-section of the hump section of the siphon outlet conduit decreased gradually, the average velocity circulation decreased gradually and the axial velocity distribution uniformity increased and tended to be stable; water flow stratification existed under three characteristic conditions with no circulation, and the hydraulic loss was greater with the circulation flow while it had a circulation under the small flow condition. Under the low flow rate conditions, the hydraulic loss was 6.6 times higher under the condition of circulation than without. Under a high flow condition, it was 1.3 times. Under the condition of a small flow rate, the vortex structure was distributed centrally at the inlet of the flow conduit, and under the other two characteristic conditions, the vortex structure mostly appeared as a strip; the pressure fluctuation in the hump section had obvious periodicity, and with the increase of the flow rate, the maximum pressure fluctuation amplitude in the hump section decreased gradually; with the decrease of the rotational speed, the pressure amplitude at the same measuring point in the hump section decreased gradually and at the optimum condition. Under the following conditions, the mean value of the pressure amplitude at the top of the hump section was reduced by 69.63%, and the mean value of the pressure amplitude at the bottom of the hump section was reduced by 63.5%. Under all the calculation conditions, the main frequency of pulsation at each measuring point of the hump section was twice the frequency of the rotation.

Sign in / Sign up

Export Citation Format

Share Document