Hi Henk Thanks for your email about ASCEND. I hope I can help you to make use of it for your modelling work at Twence.
Your flash model seems to be on the right track, but I would ask one thing: how important is it that this model solves at certain 'off design' cases? For example, is it acceptable to assume that compressed liquid water will always be present at the inlet? I can help to write a working model if you tell me what assumptions can be made. FWIW there is a flash model aready in the ASCEND model library in models/flash.a4l that uses the older 'thermodynamics.a4l' fluid properties (based on Reid, Prausnitz & Poling). That model should work for chemical mixtures etc, not just pure water. But it will not be as accurate in the case of water as models using IAPWS95/IAPWS-97 steam properties (as with freesteam and/or FPROPS). Given that you are interested in Rankine cycle models, I will assume that we want to try to make use of the more accurate property data for this task. Also, your model shows a heat input. Do you want a heat input in your model really? That would make it a boiler rather than a passive flash vessel. And what are the allowable conditions for pressure drop over the flash unit? Cheers JP On 02/04/12 14:48, Henk Fikkert wrote: > Dear all. > please let me introduce myself, Iḿ Henk Fikkert from the Netherlands, > and I am working as a Chemical Engineer for Twence, a Waste Processing > and Energy company. > > A couple of years ago I ran into ASCEND, but at that time I didn dig > in too deep. Recently I rediscovered ASCEND, especially through the > Rankine cycle models of John. I am wondering I could use it for a > (simple) simulation of one of our steam cycles. Apart from the models > John has introduced, I need a steam-flash, and I programmed a simple > one (hard enough for me however) of which you find the listing at the > end of this message, > > I'm not sure if this is a right direction to continue. If someone > could have a look at the code, and give me some feedback, I would be > very grateful. > > Thanks and regards, > Henk Fikkert ------------------------------------------------------------------------------ Better than sec? Nothing is better than sec when it comes to monitoring Big Data applications. Try Boundary one-second resolution app monitoring today. Free. http://p.sf.net/sfu/Boundary-dev2dev _______________________________________________ Ascend-sim-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ascend-sim-users
