Turbocharger warm-up issues

In the case of a condensing unit, an excessive warm-up time can lead to excessively high exhaust temperatures, and the rear cylinder is prone to deformation

The prolonged low-speed warm-up time affects the dry gas seal and bearing shells

What my device says is the same as what’s indicated on the 2nd and 3rd floors.

This post was last edited by gjn1970 on 2016-10-18 at 10:58. Turbine warming-up is primarily relevant to turbines that are in a cold state; that is, the issue of warming-up arises only during cold starts. For hot or extremely hot starts, not only is warming-up unnecessary, but the turbine should also be accelerated to speed and brought to steady operation as quickly as possible after friction checks, so that it can be connected to the grid and operate under load. Otherwise, the cylinders and rotor will suffer severe thermal shock, which can lead to cracks and reduce the turbine’s lifespan. For a cold steam turbine, the main purpose of warming up is to thoroughly preheat the metal components of the turbine, thereby reducing the temperature differences between the inner and outer walls of the cylinder flanges, as well as between the flanges and bolts. It also reduces the temperature differences on the surface and at the center of the rotor, thus minimizing internal stresses in the metal. This allows the cylinder, flanges, and rotor to expand evenly, keeping the differential expansion within safe limits and preventing the loss of the dynamic and static clearances inside the turbine, which could otherwise lead to friction. At the same time, it enables the turbine to reach operating speed more quickly, reducing the time required to reach full load and thus helping to save energy. But it takes too long: 1) For low- and medium-speed warming up, once the specified time has passed, the expansion difference has already disappeared; there is no need to continue warming up, as this would result in a waste of a large amount of steam energy, and it could also cause a loss of working fluid in back-pressure units ； 2) During high-speed warm-up, the warm-up time is too long; due to the high speed, more and more heat is generated as a result of frictional aerodynamic losses, and this heat cannot be removed by the steam (because the steam flow rate is too low). As a result, the exhaust temperature continues to rise. This phenomenon occurs in both back-pressure units and condensing units, and in severe cases it can cause deformation of the exhaust cylinder, leading to changes in the bearing levels and thus inducing unacceptable vibrations. Therefore, for cold turbines, the warm-up times at low, medium, and high speeds must be strictly followed according to the times specified in the operating procedures.

The answer above is correct; it’s very detailed, I’ve learned something from it

Detailed explanations, standardized, with support! !

During the warm-up process, the rotor should be rotated; if this takes too long, poor bearing lubrication and a heavy rotor may lead to bearing wear

How was the deformation mechanism derived?

During normal operation, the exhaust temperature of a condensing unit is around 60 degrees. If the unit is kept in warm-up mode for an extended period, the heat from the steam is not used to generate power but is instead discharged directly into the condenser; this leads to a continuous increase in the exhaust temperature. Excessively high temperatures can cause the exhaust cylinder to deform, and the position of the bearings on the exhaust side may change, posing serious risks to the operation of the entire unit.

However, when the exhaust temperature rises, the system activates the final stage of spraying to cool it down, and it generally does not exceed 100 degrees. A temperature difference of 40 degrees should have a relatively small impact on the bearing center of the low-pressure cylinder