How to ensure that the upper and lower cylinder temperatures are within a reasonable range during the startup process of the steam turbine
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The unit has newly overhauled a steam turbine. During the startup process, due to the large temperature difference between the upper and lower cylinders, which is about 130 degrees, the vibration during the rush and rotation process exceeded the standard and the machine stopped. How can I reduce the temperature difference between the upper and lower cylinders?
Are you sure the temperature difference is too large or the vibration exceeds the standard?
This post was last edited by Zhongyuan people on 2016-11-3 20:08 The temperature difference is huge. You can run it at a low speed of 1000rpm for 1 hour with a uniform temperature, then increase it to 1500-2000rpm and run it for 30-50 minutes depending on the temperature difference. After passing the critical point, stay in the minimum allowable speed zone for 1 hour. If the effect is good, then adjust it to the normal speed.
At 800 rpm, the vibration exceeded the standard and the machine shut down.
This post was last edited by Zhongyuan people on 2016-11-4 01:08 Did you turn the car during the warm-up? Pay attention before driving; 1. Turn on the car before heating pipes and sealing steam. ； 2. When preheating, cranking is required, and the time should be sufficient to ensure that the temperature difference between the upper and lower cylinders of the steam turbine is below 20°C; 3. Pay attention to hydrophobicity of the steam, and do not bring condensed water into the steam turbine.
All these tasks have been done, but the temperature difference is difficult to guarantee. We dropped it to 50 degrees at the lowest.
The maximum temperature difference is only 50 degrees. No matter how big it is, there is no guarantee of overturning. Check whether the insulation is not done well. The insulation of the lower cylinder is thicker than that of the upper cylinder. Which temperature is higher in the upper and lower cylinders? What is the lower cylinder temperature? If the lower cylinder temperature does not exceed 100 degrees, the cylinder drain should be clogged. Check it out
Check whether the water drainage is not smooth, whether the liquid level is high at low pressure, and use a single valve to control the steam intake all around. Is the temperature of the pressure equalizing box normal?
1. First, make sure that the heating pipe is warmed, otherwise the condensate brought into the cylinder will definitely vibrate greatly. 2. Make sure that the traps are open before the steam enters the cylinder. 3. Check that all the traps are smooth after the steam enters. 4. Try to warm up the engine at a low speed for a long time. Generally speaking, it is 500 rpm for an aviation steam engine. Normally speaking, there is no such a big temperature difference between the upper and lower cylinders after such a warm-up.
We also encountered this problem. The temperature difference between the upper and lower cylinders is almost 80 degrees. The engine is fully warmed up. The temperature difference is about 20 degrees during warm-up. As the temperature rises, the temperature difference also increases. No problem with insulation. Now the low-pressure cylinder delivers water, the middle plane water delivers, the high-pressure cylinder delivers water under one roof, and the quick-closing valve delivers water normally open. I wonder if the water delivery is always open and there is no stuffy cylinder. I hope someone can answer it.