Title：Some apects of research on Hydrodynamic machine

Reporter： Bhupendra Kumar Gandhi

Time：Dec. 7th (Thursday) 2:30pm-5:00pm

Site：A-260, Lee Shau Kee Building of Science and Technology

Inviter： 祝宝山老师

Abstract：Slurry transportation systems have been used all over the world as an effective and cost saving method of conveying bulk solids in various industrial applications. The pumping unit is one of the most important components in the system. A centrifugal slurry pump is mostly used in a large number of industries for small and medium distances transportation of slurries. The performance of the centrifugal slurry pump plays an important role for successful and economical transportation of solid-liquid mixtures in the hydraulic transportation system. In India, the disposal of ash slurry from thermal power plant to the ash ponds is a major problem. To develop the understanding of economic transportation of ash water slurry through centrifugal slurry pumps, experimental investigations were performed on different size pumps with bed ash and fly ash slurries of different particle sizes. The investigations were also carried out for the enhancement of the pump performance with the addition of fine solid particles in the coarse slurry.

The facility of on-site performance testing and field acceptance test to determine the performance of small hydro power plants has been developed and so far efficiency of around 175 plants has been evaluated. The efficiency tests are performed by mostly two type of methods a) Head and Discharge measurement method (for all heads) b) Thermodynamic method (for high head). Recently hydraulic efficiency measurement by thermodynamic method has been performed at two hydro power plants with an uncertainty of around 1%. Further the power generating units including turbine needs to sustain sudden change in its operating conditions to balance the grid frequency. Thus, hydro-turbines experience more starts and stops per day, which causes the key problem such as fatigue to the runner, instrument malfunctioning, vibration in the system, wear and tear, and runner life reduction. The experimental and numerical investigations were performed over a wide range of operating conditions of a hydraulic turbine in collaboration with Sweden and Norway. This research has suggested some optimization techniques to minimize the damages to hydropower plant especially turbine, during the peak and base load demand. Presently, we are working on a R&D project (funded by CPRI, Government of India) which aims to identify the countermeasure technique to mitigate the vortex rope and to increase the plant efficiency at the off-design conditions.

Erosion wear of the hydro turbomachine components due to impact of suspended solid particles is also a major problem that affects its service life and efficiency. The experimental studies were performed in the pilot plant test loop and the erosion wear of a slurry pump casing was investigated. It is difficult to investigate the wear behavior of the components handling the suspended solids from actual field data or pilot plant due to its complex behavior. Accelerated wear test rigs were preferred to develop the understanding of wear behavior. A slurry pot tester is used to generate the erosion data for different target materials. The erosion studies were also performed with different coatings materials to provide the alternative method to enhance the service life of the components. Presently, we are working on investigating erosion wear due to suspended solid particles at higher velocities using pot tester and to develop a methodology for predicting the erosion of hydro turbomachine components.

Brief Biography：Bhupendra Kumar Gandhi is Chair Professor, Hindustan Aeronautical Limited, India and Professor in the Department of Mechanical and Industrial Engineering at Indian Institute of Technology (IIT), Roorkee (India). He is chairman of the Technical Committee on Hydro research, Ministry of Power, India. He graduated from Shri Govindram Seksaria Institute of Technology and Science, Indore in 1984. He obtained postgraduate degree in Thermal and Fluid Engineering from IIT Bombay in 1992 and Ph D. from IIT Delhi in 1998. He was awarded prestigious JSPS post-doctoral fellowship and DST-DAAD project based personal exchange program to conduct research on pumps. He has published more than 140 research papers in National and International journals/ conferences. He has successfully completed 10 research and 100+ consultancy projects on industrial problems.

He is instrumental in the development of the facility of the on-site performance of hydropower plants and so far efficiency of more than 175 plants has been evaluated including some work for the Renovation, Modernization, Uprating and Life Extension (RMU& LE) and Operation and maintenance (O&M) purposes. Recently, he performed efficiency test using the thermodynamic method according to IEC-60041. The test has the capability of on-site performance with less than ±1% uncertainty. He has also developed a unique design of pot tester (under patent) for evaluating erosion wear of hydropower components. He has supervised the experimental and numerical investigations on a wide range of operating conditions of a hydraulic turbine in collaboration with Sweden and Norway. This research has suggested some optimization techniques to minimize the damages to hydropower plant especially turbine, during the peak and base load demand. Presently, he is working on a R&D project (funded by CPRI) which aims to identify the countermeasure technique to mitigate the vortex rope and to increase the plant efficiency at the off-design conditions.

He has successfully completed many research and consultancy projects on industrial problems. He has developed BIS test facilities for pumps at Indore, India and also has been instrumental in setting up in-situ test procedures for small hydropower plants at Roorkee. As a team member, he has specifically contributed to measurements of head and discharge. He has developed an indigenous impeller for Indian railway as a replacement of an imported one thereby reducing the cost by a factor of 100. He has also proposed an aerodynamic design of Indian train which may result in saving of the fuel cost leading to large saving in running cost. He has trained around 400 technical officers of Uttarakhand on the design, construction, and maintenance of water supply schemes in hilly and remote areas. He has imparted latest available technical knowhow on pumping systems for the benefit of society.