大尺寸混流式水轮机热力学法效率测定研究与应用

Study and application of thermodynamic efficiency measurement on large-scale turbine

摘要

针对热力学法在进行水轮机水力效率测定时，测量断面温度和能量分布对测定结果影响，介绍了热力学法的基本原理，阐述了热力学法测定水轮机效率的基本依据，然后对一特定的大尺寸混流式水轮机开展了能量分布的数值计算，最后实现了现场测定应用。研究结果表明，大尺寸混流式水轮机高压侧断面能量分布均匀，现有的取水测量方式可得到可靠的测量结果；低压侧测量断面能量分布不均，需布置尽量多的测点以得出断面的平均能量；取水测量装置与外界的热交换需开展特定的测量，以得到特定取水流量下单位机械能的修正项。研究结果是大尺寸混流式水轮机开展热力学法效率测定的一次成功应用，值得同类水轮机在热力学法实施时予以借鉴。

Abstract

Focused on the influence of the energy distribution in thermodynamic efficiency test on turbine, the basic principle of thermodynamic method is firstly introduced in this paper. Hydraulic efficiency of turbine is worked out based on the first law of thermodynamics accordingly. Numerical calculation is performed on a large-scale prototype turbine then site measurement is carried out. Study result show that energy distribution at high-pressure section is circularly symmetrical and sampling measurement may obtain reliable result. Energy distribution at low-pressure section is rather asymmetrical and is affected obviously by the operation condition. As more as possible measuring points are needed at low-pressure section to obtain the average energy. The heat exchange of the sampling device during thermodynamic measurement need specific measures to get a correct specified mechanical energy of turbine.

关键词

水电站 / 混流式水轮机 / 水轮机流量 / 热力学法 / 能量分布

Key words

hydropower station / prototype turbine / turbine discharge / thermodynamic method / energy distribution

Author summay

王 涛(1990—), 男, 高级工程师, 学士, 主要从事水电站水轮发电机组及辅助设备检修维护。E-mail: [e-mail]

基金资助

三峡金沙江云川水电开发有限公司禄劝乌东德电厂科研项目(Z522302058)