The Calculate Of Large-Scale Hydraulic Turbine With Regard To Self-Balanced Static Pressure Axial Seal

This article is summarized from pre-research of hydropower plant produced by Harbin Electric Machinery Co., Ltd., largest hydropower turbine-generator unit with capacity 677MW in china up till now.Shaft seal is key part of hydro-turbine components. Its utility is to seal pressure water between rotating parts and stationary parts. Its quality affects the security ability and inspection period of unit and further, affects the client's economic benefit and manufacturer's reputation. Axial self-balanced static shaft seal is a new fashioned one utilized in large capacity hydraulic turbine-generator unit, which has advantages such as excellent seal performance, long operation period, good self adjustment performance, wide compensating scale etc. The key point for designing and application of this shaft seal is to find out the interaction regulation among construction parameter, operation and control parameter and performance parameter. Further is to quantitatively analyze and control key seal performance parameter such as flow distributor value, pressure distributor value and gaps variability value etc. Notwithstanding some domestic producers had statistical data and researched this issue, but because the seal performance cannot be quantitatively controlled, this kind of shaft seal is not widely utilized on other large-scale unit.This article applies adhesive fluid theory of hydraulic dynamics within narrow gap of parallel surfaces (areas), considering inertia strength, in order to study hydraulic turbine's inside fluid principles and characteristic. It concludes the distribution function between pressure and velocity. Moreover, it gives a solution to the calculation of flow and force feature within seal gaps, that means it gives the relationship among parameters such as seal pressure, control water pressure, seal gaps, flow, apparatus to be forced etc in working condition, which realizes quantitative analysis in the shaft-seal design of large-scale hydraulic turbine. On this basic, make time to optimize design, find out the first-rank ratio of l1 and l 2. More over, utilize the CFD technique to calculate the performance of the hydraulic turbine, make sure the design more believable.