Fire detection of transformer and generators 1

[plutonium11]

Hi everyone!

I got a request to make designs of fire detection system of transformer 10/0,4kV and power generator 10kV. Location Europe. As I have little or no knowledge in designing such fire detection (I designed a lot of residence projects) I seeked for a help from equipment manufacturer (fire detection) and I got some solutions.

However, I would like to hear experiences and other thoughts from electrical engineers itself, but not only from sales persons.

How do you make early fire detection of transformers or power generators?

Thanks and regards.

 

[catserveng]

On the generator side, there are a lot of "it depends" that go into the decision process.

Smoke detectors are almost worthless, as normal maintenance activities and minor mechanical issues can cause low levels of smoke in engine rooms.

Heat detectors are better if properly placed to monitor for abnormal enclosure or space heat.

Most data center systems I work on use optical flame detectors or a form a video image detection tied to their security systems.

This is from a website of a company I have worked with in the past,
Most fires caused by generators are fast flaming fires, so the detection technique is to look for heat or flame caused by the fire. Smoke, while present, will not be a good first indicator of a fire. Heat detection is the first consideration. Heat detectors are reliable and economical, but when businesses consider the mission critical nature of their generator equipment, they generally add some form of early detection. Many generator installations use optical flame detectors for automatic fire detection. Flame detectors quickly identify the presence of a flame. Some facilities elect to couple their automatic detection method with their security system and install a Video Image Smoke Detector (VISD) for fast detection and video images to know what is occurring within the room before sending personnel in to address the problem.

The type of engine/generator enclosure or space will dictate the best detection methods. A small sound attenuated enclosure may not effectively work as desired with heat detectors depending on enclosure air flow and free space above the generator set.

Ideally you would want to engage a supplier who has actual experience in dealing with these type systems. I occasionally get callouts for reported genset fires that are nuisance problems with their detection systems, most cases not the right type system, not properly installed or not maintained/tested as required.

There was a fire detection and suppression company in Holland who did a lot of work for data centers and oil/gas facilities, but I can't find their info, will look around some more and will post their info if I can find it.

Hope that helps, MikeL.

 

[7anoter4]

In my opinion, NFPA 850/2010 it is the standard for Recommended Practice for Fire Protection for Electric Generating Plants and High Voltage Direct Current Converter Stations.
For instance chapter 5.1.4 Outdoor Oil-Insulated Transformers , 5.1.5 Indoor Transformers and 7.7 Turbine-Generator

 

[itsmoked]

Several places I've worked at had fast detect systems. None of them were heat related. They all used ultraviolet detectors. Open flames give off ultra-violet light that should otherwise never be present in a space even when hot exhaust manifolds might be present.

In Oroville Dam's transformer vaults, which are inside the rock of the power-plant, they use UV to trigger massive CO[sub]2[/sub] dumps. They disable them before you enter a vault as you wouldn't make it out, aka Terminator, if they triggered. Also UV is used at all Alyeska pumping stations in hopes of heading off massive oil fires. One caveat is that classic camera flash strobes give off UV that triggers UV sensors. (Not smartphone LED flashes.)

A gas elevator kiln I recently worked on (fed with a 14" gas line) used UV sensors on each of the 8 burners to detect if the UV ceased so it could instantly cut of the fuel to a burner that went out or never lit-off.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[plutonium11]

Thank you for answers! Helped me a lot. Did my own research based on your answers and have some ideas.


Transformer... I have in plan to cover it with IR flame detection. Transformer has its own bucholz relay and other safety devices, but this is not in my scope, so I must provide second degree protection/fire detection. As transformer will be warm in its daily work, does it emit IR and can it cause false alarms? Do you prefer UV over IR, or combination is the best?

Also, I have in plan to user IR flame detector on generator side as well.

What happens in case of maintenance, hot works like welding, grinding etc.? I'm thinking to temporarily switch off zone where works are executed, but is it good solution?

 

[crshears]

Dear OP,

You may not get very many if any more responses, since you seem to be wanting to ignore the advice given.

Just saying.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]