2 replies to this topic

[kasri]

Dear All,

When I run the flarenet simulation for a PSV-blocked discharge case(two phase-oil well with asso. gas) , I got a message " Possible slug flow in pipe".

Tail pipe is sized based on two phase relieving criteria of Mach=0.25 and rv2=50000.So tailpipe is already endup with bigger size. Eventhough we selected higher size of tailpipe and header we have a message as mentioned.

So please advice how to handle this , whether is it really impact the vent system because the selected tailpipe and header results mach no. less than 0.25 and rv2 less than 3000.

Regards,

Kasri

 

[Erwin APRIANDI]

Hi kasri,

 

In what equipment does this PSV-blocked discharge case happen, and does it really going to relief a two-phase flow? Please to understand the scenario first, and you can also share it here for our better understanding.

 

And for the warning of "possible slug flow in pipe", it is from the flow regime results reported from the flow map or from pipe summary? Cause sometimes this results may differ, there's a reason behind this that has been explaned by Aspentech in their Technical Support Website.

 

Usually slug will happen if your velocity is low, so for now due to lack of info I can only suggest to try to reduce the tailpipe size, to as low as possible based on the criteria that you are using. As you mentioned in your post, "the mach no is still less than 0.25 and rv2 less than 3000" so I you may still able to optimize further here.

 

hope it help

[Jiten_process]

Moreover, I would also suggest to check manually whether the slug flow really occurs or no. you might have spreadsheet or some calculator to size two phase flow lines. This is because i also encountered a situation where i was getting such warning but actually the slug flow does not exist. Obviously that time we didn't care to get the explanation from Aspentech as we were running out of time on schedule. 

 

Also check, are you getting this warning for other PSVs also in network (if you are making a network of PSVs). This might give you some indication as to where is the problem. 

 

good luck...

Edited by Jiten_process, 05 January 2014 - 06:56 AM.