Axial hydraulic thrust is a crucial factor contributing to the unstable operation of pump-turbine especially under off-design conditions. Pressure-balance pipe can effectively achieve axial balance pump-turbine. In this study, impact diameter and location pressure-balance on runaway condition investigated. The influence mechanism pressure distribution internal flow patterns further explored. results show that pipes have relatively minor while increase in causes rise thrust. Compared with...

Pressure fluctuations in the draft tube mainly arise from rotational motion of vortex rope. The formation and development rope are significantly influenced by cavitation. However, precise mechanism underlying progression cavitation its initial weak state to a more severe level remains unclear. objective this study is investigate pump-turbine operating under part load turbine conditions. Numerical simulations were conducted analyze impact coefficient on various parameters, including vapor...

Pumped storage hydropower is perhaps the most reliable solution to energy crisis, but its development and application are limited by hydraulic instability, such as S-shaped characteristics. In this paper, based on region pressure fluctuation test of a model pump turbine, connection between guide vane opening established, 28 mm selected for numerical analysis expand discussion characteristics large openings. The frequency components vaneless space extracted fast Fourier transform analysis,...

Cavitation is recognized as a phenomenon that can cause serious damage to hydro turbine and reduce its performance when operating at off-design point. This an undesired phenomenon, which needs be improved. In order suppress the cavitation in Francis draft tube, technology with grooved tube named J-Groove introduced turbine. The internal flow characteristic are investigated both without installation by experimental method numerical simulation. Visualization was used capture rope compare...

The temperature of the main engine cabin commercial vessel is very high. material SS-316L undergoes creep damage at temperatures exceeding 450°C. It essential to maintain highly stressed below regime. Hence, seawater employed in this kind maritime vehicles as cooling liquid. obtains thermal energy pipe line after passing through system. To harness seawater, a turbine can be installed absorb before being released into sea. In study, selected apply tubular type hydro for transferring energy....

In this study, a Francis turbine with specific speed of 130 m-kW was designed on the basis port area and loss analysis. The meridional shape runner focusing mainly combination guide vane analysis experience. blade inlet outlet angles were by calculation Euler’s head, while modified keeping constant at outlet. results show that effect flow exit angle from passage is significant. A correct reduces energy draft tube, thereby improving efficiency turbine. best 92.6% achieved method, which also...

Sediment erosion is the wear phenomenon from hard abrasive particle found in rivers. an inevitable process hydropower. It deteriorates turbine shape and structure increasing maintenance expenses. There are various methods to improve runner operate against sediment erosion. Firstly, material can be modified harder but it will costly difficult for manufacturing. Secondly, regular of needs done tedious task hinder power generation Thirdly, critical area blade surface which vulnerable need...

When cleaning the surface of a glass greenhouse, washing machine often encounters slippery tracks or strong winds, in which case is very likely to deviate from axis greenhouse. In order improve stability and reliability greenhouse cleaner under different working conditions, this paper studies controller puts forward fuzzy PID control scheme optimized by PSO algorithm. Using Adams Matlab jointly simulate model, results show that particle swarm has best effect can make adaptable variety...

In order to increase pump efficiency and apply an optimum design method of a low specific speed centrifugal less than 127 [m, m3/s, min-1], twelve kinds volute casing with the same impeller are designed at blade outlet angle 34 degree. With each tongue shape, there is one casing, respectively. The effect these shapes investigated by using computational fluid dynamics (CFD). this present study in combination shape operating variables for performance enhancement analyzed. Based on experiments...

In order to address the time-consuming and labor-intensive challenges as well suboptimal operational quality encountered in conventional processes of fruit bagging within expansive orchards, an innovative end-of-bagging actuator is proposed, which can be installed on a fruit-production robot. Due excessive power sources required complete operation, while also taking into account cost end effector, we have implemented clutch transmission system control individual motors, thereby achieving...

Abstract The pressure fluctuation caused by vortex bands is the main cause of vibration in Francis turbines under off-design conditions. Therefore, adopting effective strategies to affect rope and suppress great significance for stable operation turbine. In this study, damping grid were proposed optimize flow state fluid draft tube, unsteady numerical simulations performed determine their mechanism action. And a detailed analysis was conducted on test results understand impact grids turbine...

This study investigates the impact of working clearances on internal flow field, pressure pulsations, and radial forces experienced by a hydrogen circulation pump. Numerical calculations are conducted seven sets distinct for The research findings demonstrate that an increase in meshing clearance results higher leakage rate during compression exhaust process, leading to decrease pump's rate. When increases from 0.15 0.21 mm, actual pump decreases 37.46 32.73 m 3 h −1 . Similarly, when 0.18...

Abstract The oceans occupy nearly 71% of the Earth’s surface area. ocean is rich in energy, and wave energy one its important components. Therefore, study generation devices an issue. In this paper, we analyze effect size air chamber structure on OWC (oscillating water column) conversion device under action unidirectional regular waves. To performance real sea conditions, climate at Sanmenxia used as experimental parameter. characteristic response with variation incident height, width front...

Abstract For pump-turbine, axial water thrust can cause damage to the unit. It is important realise automatic levelling by using pressure balance pipe. To study influence of pipe on performance reversible and fluctuation have been carried out for pump-turbine with different guide vane opening operating heads numerical experimental analysis. The unsteady simulation results full flow channel show that 298 mm blade meets test standards power. Furthermore, CFD tests were at 298mm opening. At...

Sediment erosion is the main problem for hydropower situated in South Asia and America. Due to sediment erosion, those areas cannot operate their full potential. a significant turbomachinery associated with degradation of turbine performance. The removes material from its surface. It can cause fracture turbine, which leads an economic loss. In this paper, properties influence on have discussed. like shape, size, concentration direct erosion. numerical analysis was conducted visualize Francis...