Sudden interruption of 1.0Mpa steam
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The fractionation tower and the heavy diesel side-stream tower in our plant’s hydrocracking unit are stripped using superheated steam heated in the convection chamber of the feed heater for the fractionation tower. The steam supplied to the heater comes directly from a pipeline system at 1.0 Mpa, and there is only this one steam line! Now the 1.0 Mpa steam supply has been suddenly interrupted; I think the furnace tubes might be burning out due to lack of steam. Do any of you experts have any solutions? (without shutting down)
10 kilograms of steam can’t just disappear all at once, right?
I specialize in catalysis and don’t know much about hydrogenation. You said, \"When the steam supply at 1.0 Mpa is suddenly interrupted, I think the furnace tubes might burn out due to lack of steam.\" With no heat source available, how is it possible for burning to occur?
That can’t be right – where has the backpressure steam for the steam turbine in the hydrocracking unit gone? It should be connected to a 1.0 MPa steam source, so that the device will not experience a steam supply interruption even if there are problems with the system ； If the 1.0 MPa steam supply is interrupted, it depends on the material of the furnace tubes in the convection chamber; carbon steel certainly won’t work, as dry burning will definitely cause damage. Cr-Mo steel is a better choice, as it can withstand temperatures up to 450 degrees, but it still cannot handle such conditions for long periods of time – the furnace will have to operate at reduced capacity.
In hydrocracking units, the steam supply at 1.0 MPa is mostly excess; it can be generated either by compressors and turbines or through the use of waste heat, so it is entirely possible to provide only that amount. Why did it get interrupted there? The process design is unreasonable
Then there’s only one option: cooling down. If the compressor 5 hasn’t stopped, there should be steam
In the situation you described, the only option is to park; there can be no other choice
It mainly depends on the specific circumstances: 1. If the water supply is interrupted, report to the dispatch team and unit management, contact the dispatch team to reduce the reaction temperature and the temperature of the distillation tower heaters, and increase the circulation rate； Water supply is normal; the startup procedures have returned to normal ； ⒉If the water pipe breaks in the convection section of the heating furnace, report to the dispatch team and unit management, cut it off, use steam from the pipeline network to continue production, and wait for further handling.
When there is a loss of 1.0 MPa in the steam supply, the alarms related to the steam flow rate and steam head pressure will activate your ESD system. As a result, the temperature in the convection section will rise rapidly, and the HH temperature alarm will also be triggered. All of these alarms will cause the ESD system to initiate a shutdown procedure: the burners will be completely turned off, the heater will be shut down, and the system will gradually cool down. Therefore, the pipes in the convection section should remain intact. By the way, you can connect a temporary N2 line to slowly introduce N2 into the steam pipes in order to flush them out and help them cool down gradually, thus ensuring proper protection. Good luck!
Our 3.5 Mpa medium-pressure steam is used only in the turbine of the cyclic hydrogen compressor, and the turbine is a condensing type rather than a backpressure type – that is, after passing through the turbine, the steam turns directly into water, rather than becoming low-pressure steam!
The outlet vent can be opened, while simultaneously reducing the temperature of the flue to prevent the furnace tubes from overheating
It depends on the dry cooking temperature. Is there a temperature display? That can be used to determine it. Additionally, the duration of time is also an issue; a short duration isn’t a big problem
Let’s see if we can find the cause in a short time; if not, then stop the car. Safety first
1. Immediately close the superheated steam valve of the heavy diesel side tower to prevent oil from entering the steam line. 2. Contact the dispatch team to reduce the volume of production in order to lessen the load on the heating furnace, and decide whether to shut down the operation based on the situation. 3. The furnace tubes won’t have major problems in the short term!
That can’t be right – where has the backpressure steam for the steam turbine in the hydrocracking unit gone? It should be connected to a 1.0 MPa steam source, so that the device will not experience a steam supply interruption even if there are problems with the system