Steam mixing problem at different pressure levels
Thread Content
This post was last edited by WoAiMaoMaoRan on July 10, 2016, at 04:03. Our company directly connects the catalytically produced steam to the low-pressure steam main pipe (DN200) of the cogeneration system. The flow rate of the steam generated by thermoelectric conversion at the pipeline connection is approximately less than 10 tons, with a pressure of around 0.87 MPa and a temperature of 260°C. The flow rate of the steam produced internally is about 10 tons, with a pressure of 0.96 MPa and a temperature of 240°C. In actual operation, the secondary steam often experiences pressure buildup. Can’t send it out. I would like to ask everyone: is the pressure between 0.87 and 0.96 when two streams of steam are mixed?
The pressure after mixing will not be higher than that of the lower-pressure side.
This post was last edited by ylb913 on 2016-4-1 at 16:18. Since your steam at 0.87 MPa can flow in that direction, the pressure after it merges will not be higher than 0.87 MPa; low-pressure steam does not flow automatically toward areas of higher pressure. The 0.96 MPa steam pressure buildup occurs in the pipe section before the pipes converge; this is due to either the narrow diameter of those pipes or an excessively long pipeline length – in short, the pressure drop in that section before convergence is too high.
I see; after mixing, the pressure cannot exceed the minimum value. That’s why in the original setup there are high-pressure and low-pressure sections, as the high-pressure pipeline would otherwise experience pressure buildup.
It can be considered from two aspects: one is the amount of steam used by the user, and the other is the diameter of the steam pipeline. Consider changing the pipeline and/or installing a safety valve for discharge, or adding condensation cooling.
I’ve learned something. I agree with what you said: if the pressure is higher than 0.87, then it’s not possible to go below 0.87. At the moment, it’s unclear as to how the steam flows within the pipeline network; it’s possible that the steam from the thermal power plant is not strong enough to overcome the pressure from the steam being sent out via catalytic processes, and as a result, that steam also flows back toward the upstream devices. Because the catalyst is located at the relatively end of the steam pipeline network, with only a gasoline hydrogenation unit following it. The amount of this pipeline used in gasoline hydrogenation units is only 3.5 tons.