How calculate combustion spread

ControlEng999,

Thank you for the information.

I am surprised at your surprise at the lack of tripping during first fire activities.

Best of luck with the remainder of commissioning.
 
ControlEng999,

I've been looking over the values in the screenshots you sent; there are several which just don't pass the sniff test....

A_CTDA_SL is the SAME signal for both CTDA inputs.... AND the value is 33.39 deg C.... For axial compressor discharge temperature. That seems ... odd.

The values being passed to KSPL6 and KSPL7 (SELECT_1:OUT and SELECT_2:OUT) are also the same value: 140 deg C. That also seems ... odd.

Finally, the values of actual spreads, A_TTXSP1, A_TTXSP2 and A_TTXSP3 are pretty darn close to TTXSPL.

We can't see the entire combustion monitor bit of application code, so we are left to wonder about the above values.

We also don't know what the operating condition was at the time the screenshots were taken: FSNL. Spinning Reserve, 20 MW, etc.

But, it's just odd that, one, the CTDA values are so low, and two, the spreads are so high. 100+ deg C for actual spreads whilst operating on gas fuel is pretty darn high.... And, close to the TTXSPLn values.

Just some observations.
 
ControlEng999,

I've been looking over the values in the screenshots you sent; there are several which just don't pass the sniff test....

A_CTDA_SL is the SAME signal for both CTDA inputs.... AND the value is 33.39 deg C.... For axial compressor discharge temperature. That seems ... odd.

The values being passed to KSPL6 and KSPL7 (SELECT_1:OUT and SELECT_2:OUT) are also the same value: 140 deg C. That also seems ... odd.

Finally, the values of actual spreads, A_TTXSP1, A_TTXSP2 and A_TTXSP3 are pretty darn close to TTXSPL.

We can't see the entire combustion monitor bit of application code, so we are left to wonder about the above values.

We also don't know what the operating condition was at the time the screenshots were taken: FSNL. Spinning Reserve, 20 MW, etc.

But, it's just odd that, one, the CTDA values are so low, and two, the spreads are so high. 100+ deg C for actual spreads whilst operating on gas fuel is pretty darn high.... And, close to the TTXSPLn values.

Just some observations.
It was FSNL mode, but of course they were close to allowable spreads
 
ControlEng999,

" ... but of course they were close to allowable spreads ...."

What does that mean, please? What do we not know about this unit? Is there something special/unusual about the combustion system? The fuel delivery system? Why would one expect actual exhaust temperature spreads to be high at FSNL on "first fire?"

I'm SOOOOO confused!!!

I try to learn something from these posts--and I actually do learn a lot, technically and professionally and human nature-wise as well. I completely fail to understand the above statement. Complete failure of understanding.

We have jumped through hoops for this thread--hoops I don't usually jump through (calculating TTXSPL, for example)--and this is what we get in return. " ... but of course they were close to allowable spreads ...." We (well, one of us) has been patient waiting for feedback. And this is what we get.

This whole thread makes absolutely no sense. "[I demand someone] tell me how to simply and easily calculate TTXSPL." "Oh, well, I can see it's difficult, so never mind." " ... but of course they were close to allowable spreads .... "

No. Sense. What. So. Ever.
 
ControlEng999,

" ... but of course they were close to allowable spreads ...."

What does that mean, please? What do we not know about this unit? Is there something special/unusual about the combustion system? The fuel delivery system? Why would one expect actual exhaust temperature spreads to be high at FSNL on "first fire?"

I'm SOOOOO confused!!!

I try to learn something from these posts--and I actually do learn a lot, technically and professionally and human nature-wise as well. I completely fail to understand the above statement. Complete failure of understanding.

We have jumped through hoops for this thread--hoops I don't usually jump through (calculating TTXSPL, for example)--and this is what we get in return. " ... but of course they were close to allowable spreads ...." We (well, one of us) has been patient waiting for feedback. And this is what we get.

This whole thread makes absolutely no sense. "[I demand someone] tell me how to simply and easily calculate TTXSPL." "Oh, well, I can see it's difficult, so never mind." " ... but of course they were close to allowable spreads .... "

No. Sense. What. So. Ever.
CSA English language is not my mother tongue, I meant that spreads were high during that start up, and of course as you said I used trender for data analyzing ,
If you want I could share the Trend with you.
 
"Why would one expect actual exhaust temperature spreads to be high at FSNL on "first fire?""
Because the quality of construction and installation was so low that I thought we couldn't avoid troubles with combustion system.
 
Next time, I will take screenshots at time of FSNL, Base load or part load, but may be I am mistaken that gave screen from FSNL,
AND of course it is unusual case with CTDA and etc. but anyway unit was running that moment, and exhaust temperature array was normal without fails and abnormal values.
 
ControlEng999,

A lot of posters and contributors here on Control.com do not speak English as their primary language. We mostly get along just fine, but there is the occasional incident where, mixed with cultural differences, the discussion can go sideways. We have reached that point in this thread, sir.

In the English language, using "of course" implies the reader is or should be aware of something which is obvious to the writer (speaker). Sir, we are not there alongside you. We are not able to see what you can see. We have not been able to experience what you have experienced. Unless you tell us, we don't--and can't--know. Personally, I was offended by your use of 'of course.'

I'm very sorry to hear of the poor construction; it makes for difficult times during commissioning and initial operation, as well as later. We have tried to offer help and point out some possible areas of concern, but we have been met with scorn and disbelief.

Maybe someone else will step up and try to help you.
 
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