Assembly Defects Detection in the Stator Core of a Powerful Turbine Generator
Keywords
Abstract
In this paper technology and device for automated detection of the location and size of defects in the stator core of a powerful turbine generator (TG) during assembly at the manufacturing plant is proposed. The core is assembled and pressed in a vertical position in separate parts and at each stage of assembly it is necessary to find places with a weakened solidity. Existing control methods, including automatic ones, will not allow quality control. Using the proposed technology, places in the core with weakened solidity can be detected. In this case, measurements of the specific pressing pressure are carried out at certain points of the end surface of the core, where special control samples from an easily deformable material are installed. The device is implemented as a ring installed on the end surface of the core, in which N cells with control samples are installed. During pressing, the thickness of the samples decreases and the greatest decrease in the thickness of the sample, caused by the corresponding highest specific pressure, corresponds to the smallest defect, and vice versa. Flat metal membrane with a rigid center as a primary pressure transducer has been proposed to use, on which an optical fiber with Bragg gratings is fixed, one of which measures the tangential relative deformation in the membrane, and the second serves for thermal compensation. In paper it has been shown that tangential deformation in a flat membrane depends on the specific pressing pressure. The characteristics of the converter are calculated. The measurement results are processed using an interrogator and a personal computer. The use of the device makes it possible to increase labor productivity when monitoring the core, as well as more reliably diagnose its defects with their subsequent elimination, which ultimately will increase the reliability of the TG and its durability.
