What are the main factors that make the turbine expansion differential increase toward a positive value? (There will be prizes for those who analyze correctly)
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What are the main factors that make the turbine expansion difference increase toward a positive value? This post was last written by zhangya * ong edited on 2009-3-5 22:20 ]
The turbine expansion difference increases toward a positive value because the cylinder expansion rate is smaller than the rotor expansion rate. specific reasons: 1The vacuum is too large ； 2 Caused by the low-pressure warm-up of the steam turbine being insufficient before entering the medium-pressure warm-up. ； 3. The temperature of the turbine starting environment is too low, which is not conducive to the cylinder heating and expansion. ；
1) The warm-up time is too short during startup, the speed is increased too quickly or the load is increased too quickly. 2) The heating steam temperature of the cylinder interlayer and flange heating device is too low or the flow rate is low, causing the steam heating effect to be weak. 3) The sliding pin system or bearing plate has poor sliding performance and is prone to jamming. 4) The shaft seal steam temperature is too high or the shaft seal steam supply is too large, causing excessive elongation of the journal. 5) When the unit is started, the inlet steam pressure, temperature, flow and other parameters are too high. 6) The thrust bearing is worn and the axial displacement increases. 7) The thermal insulation effect of the cylinder insulation layer is poor or the insulation layer falls off. During the strictly prohibited season, the room temperature of the turbine room is too low or there is cold draft from the hall. 8) Cold steam (or cold water) flows into the interlayer of the double-layer cylinder. 9) The zero point of the differential expansion indicator is inaccurate or the contacts are worn, causing digital deviation. 10) Multi-rotor units, the mutual influence caused by the expansion difference changes of adjacent rotors. 11) Effect of vacuum changes. 12) The influence of rotational speed changes. 13) The influence of changes in the extraction steam volume at each stage. If the first stage extraction steam is deactivated, the impact will be obvious. 14) The bearing oil temperature is too high. 15) Due to the influence of the "Poisson effect" during the shutdown process of the unit.