Steam turbine exhaust

There is a negative pressure atmospheric safety valve in the surface cooler, which is mainly used when the two condensate pumps are not working, so that the pressure in the surface cooler reaches a positive pressure. When the pressure is higher than the atmospheric pressure, the exhaust steam in the surface cooler breaks through the water seal of the safety valve and is discharged to the atmosphere, which plays a role in protecting the surface cooler.

Is the steam exhausted from the rear cylinder of the turbine before entering the surface condenser a positive pressure or a negative pressure? Of course, the exhaust pipe also has a safety vent line and a safety valve. Under what circumstances will steam be discharged from the safety valve to the atmosphere? The turbine in our factory is of air extraction and condensation type and is equipped with a positive air air extractor! Thanks! Answer the question raised by the host: The steam pumped into the steam condensing steam turbine undergoes expansion at various stages to do work. The last stage (last stage) is called spent steam. It is lower than 1 atmosphere, that is, negative pressure, and has no ability to continue to do work. It enters the condenser and is cooled into condensed water for recycling and reuse. The exhaust pipe also has a safety vent line and a safety valve, which we call the atmospheric safety door. When the condenser is full of water, open the atmospheric safety door to release the pressure. The real air evacuation device configured in your factory is used to vacuum the negative pressure system.

Is the steam exhausted from the rear cylinder of the turbine before entering the surface condenser a positive pressure or a negative pressure? Of course, the exhaust pipe also has a safety vent line and a safety valve. Under what circumstances will steam be discharged from the safety valve to the atmosphere? The turbine in our factory is of air extraction and condensation type and is equipped with a positive air air extractor! 1. The exhaust is at positive pressure, 2. When the pressure in the condenser is positive

It's positive pressure. However, under the action of surface cooling condensate water cooling and air pumping, it becomes a negative pressure.

When the steam is discharged from the turbine, it is under positive pressure. There are safety valves on the exhaust line mainly to protect the exhaust line when the exhaust valve does not work properly.

6# sean816 I don’t mean to offend the moderator, but I think what you said is indeed wrong. Let me share my opinion and let everyone discuss it! First of all, it is an extraction and condensing type, so there should be no exhaust valve. In addition, the main function of their atmospheric safety valve is not to protect the pipeline, but to protect the surface condenser. Because this equipment is designed for negative pressure, it does not allow the positive pressure to exceed a certain value! Another person upstairs seemed to say that the function of the atmospheric safety valve is to prevent the condenser from being filled with water. This is actually not entirely true. When the water level rises to a certain level, the negative pressure in the condenser will plummet, which means that the exhaust pressure will rise. When the atmospheric safety valve trip pressure is reached, the pressure is released. The purpose is to protect the condenser.~