Reducing Flame Intensity

A

Thread Starter

abdi

hi,

In my company we have DLN type GE FRAME 9E MARK V. when trying go to premix mode the flame detection trouble & failure to flame out in primary Zone alarms are appear. after that the alarm relay is active and the extended lean lean mode is appear. after that we check the intensity of flame for primary zone:

flame # 1: 92
flame # 2: 124
flame # 3: 82
flame # 4: 0

the setting flame detector for premix mode steady state is 64 cont., but during the transient mode is 128 cont. we decide to force the signal of L28FD_PRI_HI. it's means when the premix mode steady state is appear the intensity of flame detector be at 128 cont.

please help me, if we force the intensity of flame from 64 cont. to 128 cont. what happen for combustion chamber?

in my document said when the flame detector operation the intensity increased then you can reduced the intensity of flame detector, but we don't know how much?

I don't know the different intensity of flame detector from 64 cont. to 128 cont. I think two value are very small for detection of flame in primary zone when working in premix mode.
 
>No. Get someone to site to help with the issues.

You potentially have:

1. Flame detector issues-- verify the detectors are functioning properly

2. more serious--your combustion liners are compromised and the flame is indeed "twisted", causing the detectors to read what they see--a vote to do a 'minor' OH to inspect the cans/liners. There may also be some issues with the fuel nozzles that could cause this.
Since this is a DLN machine, there may some issues with the atomizing air valves feeding the cans --

check anything that has changed since the units were running ok til now when they are not.
 
hi,

you said we must check the liners & fuel nozzles. before the HGP WE have this problem for premix mode but we think this problem may be for combustion chamber equipment and we work in primary mode. after HGP WITH the new equipment of combustion chamber this problem appear.
then we think this problem refer to Intensity of flame. DURING the HGP for flame detector just clean and test it and not replace it. now we think for reduce the intensity of flame it's must be replace but we don't know is corrected or NO?

THANK YOU EVERYBODY TO ANSWER ME because we afraid a big problem appear for combustion chamber.

please help me to understand what happen may be done.
 
I wish to caution anyone responding to this thread the original poster has posted many times for help with DLN-I issues and has received many responses, to which we always learn of additional issues which indicate the unit(s) are being operated very harshly, bordering on abuse.

It's not clear that the advice or information which has been provided has been of help, allowing the poster to understand how DLN-I systems work and have to be operated--and why. It really doesn't seem to have made a bit of difference as we learn they are <b>STILL</b> operating in Primary mode because they can't reliably transfer to Lean-Lean or Premix modes.

They refuse to believe the problem is <b>NOT</b> the control system, and continue to ask how to "force" this or that to overcome mechanical/hardware/fuel issues. Because they do not--and have not tried to--understand DLN-I and its complexities. The belief at site is the control system is at fault, so, the control system is the cause of all the problems--and forcing things in the control system is the answer to all the problems.

We will never get enough information from site to know the current conditions and Control Constant values and configuration to provide meaningful help. It would absolutely be of the most benefit if the site would have a knowledgeable person come to assist--AND do some training as well as answer questions. Being on site to observe the state of the equipment and the training and knowledge level of site personnel is <b>THE ONLY</b> way the site is going to learn and understand. It's futile trying to help them here on control.com; look up past threads abdi has originated and it will become evident very quickly they need on-site assistance before they crater a machine--or worse.

Please, encourage abdi to seek knowledgeable on-site help. Forums like this can help with many problems--but not the root cause at abdi's site.

Thank you for encouraging abdi to seek knowledgeable on-site help.
 
> Why are we talking about Atomizing Air?

Sorry--mis-spoke on this. I was thinking more in the line of purge air-used on dual-fuel machines.
 
> you say the flame is indeed "twisted" I can't understand. please explain more.

Twisted flame patterns are usually the result of cracked combustion liners- allowing leaking purge air, or fuel to "swirl" more in the chamber. This can cause flame detectors to not see a full intensity flame, resulting in low intensity readings-even flame-out if it is severe enough. Lots of times this type of pattern may be due to plugged or worn fuel nozzles.

This experience is from GE 7FA+e dln dual fuel machines.
 
This is definitely not a control problem--I see your point. There are mechanical issues here that need to be addressed.

"forcing Points" is not an acceptable solution to this type of issue. The root cause needs to be identified and repaired.

>I wish to caution anyone responding to this thread the
>original poster has posted many times for help with DLN-I
>issues and has received many responses, to which we always
>learn of additional issues which indicate the unit(s) are
>being operated very harshly, bordering on abuse.

---- snip ----

>They refuse to believe the problem is <b>NOT</b> the control
>system, and continue to ask how to "force" this or that to
>overcome mechanical/hardware/fuel issues.

---- snip ----

>Please, encourage abdi to seek knowledgeable on-site help.
>Forums like this can help with many problems--but not the
>root cause at abdi's site.

>Thank you for encouraging abdi to seek knowledgeable on-site
>help.
 
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