Hi. We've dealt with commissioning

[Jack Nicholson]

Hi. We've dealt with commissioning of cold box (BAHX) and a special remark was made by vendor:

The maximum allowable temperature changes of each stream are 2 K/min but
maximal 60 K/h.

What does it mean? (I'm sorry my English isn't good, so I couldn't understand that)

 

[LittleInch]

I think it means no more than 2K/minute with an overall limit of 60 K in one hour.

So 2K per minute for 20 mins (40K) followed by no more than 20K in the next 40 minutes would be ok, but say 40K in the next 40 minutes isn't . Or any combination like that.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[rotw]

We can infer that "maximal" refer to each stream as well ..but its a little bit poorly written.

If interpretation is correct, I would have stated it:
"The maximum allowable temperature changes of each stream are 2 K/min however not to exceed 60 K in total over an hour period"

 

[Jack Nicholson]

Dear rotw.
So which constraint we should follow? 2 K/min or 60K/hr? Because if we consider 60K/hr, so in one minute we should not exceed 1 K/min. And if we consider 2K/min, So which order we should follow?

 

[rotw]

quoted/ Because if we consider 60K/hr, so in one minute we should not exceed 1 K/min. /unquoted

You made this inference yourself. You could exceed 1 k/min and overall stay within 60 K/h...

Its (roughly) similar to when you get a fine for over speeding...a camera check you when you enter and exit the highway so if you travel the total distance in less than a certain time, you get a fine. In addition, radars will check your actual speed regularly and if you over speed you get fined too...

 

[LittleInch]

Whichever rules at the time.

Aim for 60K in 60 mins but if you go faster than 1K/min then reduce rate until on avarage your on track for 60 K in 60 mins.

Just draw a graph at 1K/min and track it in reality. If you end up slower then you can speedup a little so long as you don't exceed 2K in any single minute.


Remember - More details = better answers
Also: If you get a response it's polite to respond to it.