Hello

We've done DLN tuning with DLN2.5H version Gas turbine. This is quite knew to us, we only have DLN1 before.

The problem was intermittent loss of flame during winter season.
We have quite big different temperature between summer and winter (about 40 °C )

Anyway we've completed mapping with GE's support and GT is working properly and result is as below.



This data looks increasing PM1A split schedule while CTIM(ambient temp) 0~25 °C and graph like this



So I thought when ambient temperature is 0~25 °C and low temperature of TTREF range, it make more open PM1A GCV.
But as I understood more premix fuel makes weak combustion condition.
So if they want to avoid loss of flame, this should have less fuel to DLN nozzle and more fuel to Diffusion nozzle.

What make flame stable with PM1A split schedule?
How to adjust PM4 split with only changing PM1A split schedule?

 

It is not odd to have different DLN tuning parameters for summer and winter.

Even on DLN1+.

All DLN turbines in premix steady state are on the edge of returning to Lean Lean operation.

I cannot comment on your tuning parameters. Tuning involves multiple changes to different constants.

The idea of just a split constant change is not entirely correct.

Some temp constants are changed as well.

I always make backups of the constants file before tuning.

I also require the TUNER to provide me with the changes made.

Good Luck

 

Dear Curious_One

What I attached is part of tuning report from Baker Hughes.
And they simply defined relations among TTREF, CTIM and PM1 split as a graph, so that I thought there might be relations with those parameters.

Clear one is they increase Premix split to make flame stable and it works even though NOx also increased.
But you think there are so many constants are related..OK

Thanks for reply!