Issues regarding the use of compressors for gas enrichment and turbines for waste steam utilization
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During the operation of the air compressor, at what point does the gas enrichment begin (is it when stable operation is achieved)? And for a back-pressure turbine, when does the exhaust gas generation start and affect the system piping network (is it after the air compressor has completed gas enrichment)?
It’s an explanation in a riddle-like manner; I’m not sure if it can be made clear, but here it is for your reference :) First of all, the drive for the compressor (air pressure machine) comes from a turbine (back-pressure turbine), so it’s necessary to first put the compressor in its maximum-load startup state. The turbine delivers the load to the compressor in several steps; thereafter, the compressor gradually adjusts the amount of air intake according to the set input load. Once stability is achieved, it slowly reduces the pressure by closing the vent valve as needed, until the desired pressure is reached, after which the air is sent into the system. A pneumatic compressor refers to a gas compressor; I’m not sure what “rich gas” means. I guess it might be the processing medium for the compressor?
Firstly, this turbine is of back-pressure type. Secondly, since rich gas is used as the transmission medium, the pressure at the turbine outlet must be stable and slightly higher than the pressure in the rear absorption and stabilization system; with stable parameters in this absorption and stabilization system, all conditions are met to accept the rich gas. During gas merging, it is necessary to switch between the discharge at the compressor outlet and the gas merging valve in order to ensure stability in the gas merging process; eventually, the gas merging valve should be fully opened while the discharge valve should be fully closed. The integration of the waste steam system should take place earlier than that of the rich gas system. Once the unit is operating stably and the load requirements are met, the waste steam system can be gradually integrated into the system, provided that the stability of the waste steam pipeline network is maintained.
Should the waste steam be integrated into the system pipeline network only after the turbine is running stably? Why can’t the waste steam be incorporated into the system when there is sufficient pressure during preheating?
One cannot consider only the steam system; stability of the unit must be taken as a prerequisite. Moreover, the process of connecting to the steam supply also affects the pressure of the waste steam.
By \"rich gas,\" do you mean what comes from the top of the fractionation tower in a catalytic cracking unit?
Should the issue of exhaust steam be considered only after the unit is operating stably?
I see what you mean. First, you need to connect the steam coming from the turbine to the main system; once the turbine is operating stably, then you can adjust the compressor. At that point, the anti-surge valve of the compressor should be fully open, allowing full backflow of gas. Regardless of the number of compression stages or anti-surge valves present, the rich gas at the top of the split tower should be sent to the flare – it should be introduced into the compressor gradually. It’s important to do this slowly. It’s best to use cascade control for both the compressor inlet pressure and the turbine speed, as it’s difficult to control these parameters manually