|
success-stories |
|
Solution of a Permanent Flow Induced Vibration problem for SEC |
| |
Problem & motivation:
High vibration problem of the main boiler feed pump at one of Saudi Electricity Company (SEC) power plants
|
| |
Team: Dr. Amro M. Al-Qutub and Dr. Attia Esmail (Thesis Dissertation)
|
| |
Action:
Experimental and numerical investigation of the flow induced vibration problem in a high-pressure double volute boiler feed pump were conducted. The effects of variable operating conditions and different design modifications were studied by model testing to minimize the vibration level. The Pumps are MHI- Horizontal-axis, 4-Stage, Double Case Centrifugal Pumps. The pumps vibration behaviour exceeds the adopted standard limits particularly at high speeds and off-design operating conditions. This vibration problem was transferred to other related/connected components of the equipment, such as instrument gauges and welded pipes, which led to their frequent failures. |
| |
Different trials were made to reduce the vibration level, such as conducting hot train alignment and replacing one pump cartridge with a new one, but the vibration behaviour had not changed much. Also, different vibration engineers from different companies, such as OED/SEC, BW/IP-Holland, and MHI- Japan, were involved to study the problem. To rectify the problem, they suggested to modify the design of the impellers of the main boiler feed pump. Finally, Mechanical engineering department at KFUPM was contracted to find a simple applicable solution for this problem. |
| |
Recommendation and Implementation: After completing the experimental and CFD simulations for the pump under investigation, the research team gave a recommendation of doubling the gap between impeller and volute as a suitable solution which minimizes the pump vibration levels for a wide range of operating at the expense of very small reduction in pump performance. The process of doubling this gap is very simple and can be done by hand grinder within few hours. Saudi Electricity Company asked the KFUPM research team to consult the modification process at the field. They dismantled the pump and KFUPM team supervised all the modification steps according to their vision from experimental testing and CFD simulations. After few days, the pump was assembled and put in service.
Result & Outcome: Analyzing the vibration measurements after modification, Pump vibration was reduced by 65% without affecting pump performance. This results in a recognition of the capabilities at KFUPM. |
|
|
|
