Didcot Powerstation Fire - Looks bad :(

[eharding]

Pesty said:

eharding said:

69 coupe said:

How does a Cooling Tower go on fire? I thought they were made of concrete/blocks and hot water cooled inside them giving of water vapour clouds with the vast majority now cooled sufficiently then falling back inside not unlike rain.

I have no idea about the Dicot examples, but traditionally cooling towers can contain a large amount of wooden framing.

Didn't something similar happen to a coal fired one in the north in the last few months? A welder set it on fire iirc.

That's what happens when you try to weld woodwork.

[Mojocvh]

What an unfortunate string of coincidences for the power generating community.

Sorry, for us.

[phumy]

dxg said:

eharding said:

69 coupe said:

How does a Cooling Tower go on fire? I thought they were made of concrete/blocks and hot water cooled inside them giving of water vapour clouds with the vast majority now cooled sufficiently then falling back inside not unlike rain.

I have no idea about the Dicot examples, but traditionally cooling towers can contain a large amount of wooden framing.

But even so, how can it catch fire - what would the ignition source be?

Could they be confusing it with the actual flues? I wonder what kind of carbon capture installation it had...

These cooling towers are constructed from around 10-15% (Concrete Foundation), around 60-70% Timber (main structure) and 15-20% Plastic (Internal tray elements), normally these cooling towers will be configured to that there are split into eight cooling modules in each tower so eight fans and each one can be shutdown and isolated from the system independant of the running modules, whilst still having the cooling tower in operation. All eight would normally be in service whilst the power plant would be at full load in a very hot day in the summer, during winter at full load i have seen these running with around three or four modules in service, due to ambient temperature being much lower, there is a an optimum temperature to run these towers at. There is also the maintenance that needs to be done, so the fans are taken out of service for maintenance on the fans, motors and gearboxes and whilst theres are under maint that module is shutdown and therefore "dries out". It could have been during these maint periods that an electrical fault could have developed and caught to tower alight. Almost forgot, the real nasty thing about all of this is that all of the timber is impregnated with Arsenic before construction, according to the manufacturer and designers, this will prolong the life of the cooling tower timber.

Carbon Capture is a relatively new idea (it has been spoken of for a long time but no one has come up with the huge amounts of money to implement it) and i dont think that its in service at any power plants in the UK yet.

Anyway it will mean that the national grid will now be around 780MW short this winter, unless Didcot B still has the other cooling tower to run then they may only lose half the output. Now we all know its bad news for the grid but in a way its good news for the governments nuclear policy for new builds as it gives greater need for them now but thats a different story.

[hidetheelephants]

phumy said:

Carbon Capture is a relatively new idea (it has been spoken of for a long time but no one has come up with the huge amounts of money to implement it) and i dont think that its in service at any power plants in the UK yet.

Anyway it will mean that the national grid will now be around 780MW short this winter, unless Didcot B still has the other cooling tower to run then they may only lose half the output. Now we all know its bad news for the grid but in a way its good news for the governments nuclear policy for new builds as it gives greater need for them now but thats a different story.

There's no large scale CCS in the UK, nor any planned soon. Looking at the pictures I'll be interested to see how this pans out as the cooling system looks quite modular; depending on whether there's damage to the wider cooling system it might be possible to run the unit at part-load if some cooling modules are undamaged.

[phumy]

hidetheelephants said:

phumy said:

Carbon Capture is a relatively new idea (it has been spoken of for a long time but no one has come up with the huge amounts of money to implement it) and i dont think that its in service at any power plants in the UK yet.

Anyway it will mean that the national grid will now be around 780MW short this winter, unless Didcot B still has the other cooling tower to run then they may only lose half the output. Now we all know its bad news for the grid but in a way its good news for the governments nuclear policy for new builds as it gives greater need for them now but thats a different story.

There's no large scale CCS in the UK, nor any planned soon. Looking at the pictures I'll be interested to see how this pans out as the cooling system looks quite modular; depending on whether there's damage to the wider cooling system it might be possible to run the unit at part-load if some cooling modules are undamaged.

If one one of the cooling towers is burnt down then they can still run one of the Gas Turbines along with the steam turbine. They may be able to re-configure the cooling system to run the second GT, if that is the case then they shouldnt lose too much output as the majority of the cooling water is utilised in cooling the steam condenser for the steam turbine. Bearing in mind that two towers are normally in service when two gas turbines (Units) are running, so just having one tower in service will normally only affect the output of the steam tubine, normally the split of load in one of these CCGT power plants is each GT output is 250MW and the one steam turbine is also 250MW output but that is with 2 cooling towers in service, so with only one cooling tower then the load on the steam turbine will be lower, but not necessarily half load, it will be somewhat more than half load output.

[sampsan]

hidetheelephants said:

There's no large scale CCS in the UK, nor any planned soon. Looking at the pictures I'll be interested to see how this pans out as the cooling system looks quite modular; depending on whether there's damage to the wider cooling system it might be possible to run the unit at part-load if some cooling modules are undamaged.

^^^^^^ No large scale CCS in service but planned 'White Rose Project' at Drax.... new 450MW full CC coal supercrit unit, looks firm and would class as planned soon.

http://www.whiteroseccs.co.uk/

[PRTVR]

On the north east news last night, they reported that Hartlepool Nuclear power station should be back in service by Christmas, they explained that it will only run at reduced rates, as this reduces the heat to the turbine thus reducing the chance of cracks forming, no expert here but I thought the risk of cracking would occur in a change of temperature.

[phumy]

PRTVR said:

On the north east news last night, they reported that Hartlepool Nuclear power station should be back in service by Christmas, they explained that it will only run at reduced rates, as this reduces the heat to the turbine thus reducing the chance of cracks forming, no expert here but I thought the risk of cracking would occur in a change of temperature.

I have read a little on this and think that these cracks are caused by long term radiation bombardment, not thermal stress, so possibly no relation to temperature.

[PRTVR]

phumy said:

PRTVR said:

On the north east news last night, they reported that Hartlepool Nuclear power station should be back in service by Christmas, they explained that it will only run at reduced rates, as this reduces the heat to the turbine thus reducing the chance of cracks forming, no expert here but I thought the risk of cracking would occur in a change of temperature.

I have read a little on this and think that these cracks are caused by long term radiation bombardment, not thermal stress, so possibly no relation to temperature.

Thanks for posting that, that makes more sense.

[McWigglebum4th]

phumy said:

These cooling towers are constructed from around 10-15% (Concrete Foundation), around 60-70% Timber (main structure) and 15-20% Plastic (Internal tray elements), normally these cooling towers will be configured to that there are split into eight cooling modules in each tower so eight fans and each one can be shutdown and isolated from the system independant of the running modules, whilst still having the cooling tower in operation. All eight would normally be in service whilst the power plant would be at full load in a very hot day in the summer, during winter at full load i have seen these running with around three or four modules in service, due to ambient temperature being much lower, there is a an optimum temperature to run these towers at. There is also the maintenance that needs to be done, so the fans are taken out of service for maintenance on the fans, motors and gearboxes and whilst theres are under maint that module is shutdown and therefore "dries out". It could have been during these maint periods that an electrical fault could have developed and caught to tower alight. Almost forgot, the real nasty thing about all of this is that all of the timber is impregnated with Arsenic before construction, according to the manufacturer and designers, this will prolong the life of the cooling tower timber.

Oh tecnical learny stuff

I always thought they were just big hollow concrete tubes

Though why they build power stations away from the sea is a mystery to me

[hidetheelephants]

McWigglebum4th said:

Oh tecnical learny stuff

I always thought they were just big hollow concrete tubes

Though why they build power stations away from the sea is a mystery to me

As long as there's a river handy it's usually down to where the power's needed and where the coal's coming from; the likes of Drax, Ferrybridge, Eggborough etc were built because there was heavy industry and coal fields close by and a big river for cooling.

[snowy]

McWigglebum4th said:

Oh tecnical learny stuff

I always thought they were just big hollow concrete tubes

Though why they build power stations away from the sea is a mystery to me

Ask the people of Japan, maybe the Fukushima nuclear power station would have been better placed in land to avoid the tsunami.

Just a different view

[TimJMS]

Russ35 said:

You can see the current and historical generation figures from here

http://nationalgrid.stephenmorley.org/

or

http://www.gridwatch.templar.co.uk/

Edited by Russ35 on Sunday 19th October 23:16

Wow, impressive stuff, thanks for the links. 24% from wind ATM.

[Scuffers]

McWigglebum4th said:

Oh tecnical learny stuff

I always thought they were just big hollow concrete tubes

Though why they build power stations away from the sea is a mystery to me

transport costs money (both fuel and power)

[evenflow]

[don4l]

TimJMS said:

Russ35 said:

You can see the current and historical generation figures from here

http://nationalgrid.stephenmorley.org/

or

http://www.gridwatch.templar.co.uk/

Edited by Russ35 on Sunday 19th October 23:16

Wow, impressive stuff, thanks for the links. 24% from wind ATM.

Less than 30 minutes ago, it was 24%. Now it is 10.9%.

This shows how bloody unreliable wind is.

[gruffalo]

With wind being so unreliable a source as we can see from the posts above what I want to understand is how are the fluctuations absorbed by the rest of the grid, can coal and gas power stations modulate there output rapidly and if so can they also modulate the fuel used, or do they running at optimum all the time and waste what is not needed.

I know modulation is possible for times of traditional high and low demand but is it possible on a minute by minute basis and does it really result in a reduced fuel burn?

[TimJMS]

Still at around 22%? Lovely stuff this newfangled wind

[Scuffers]

don4l said:

TimJMS said:

Russ35 said:

You can see the current and historical generation figures from here

http://nationalgrid.stephenmorley.org/

or

http://www.gridwatch.templar.co.uk/

Wow, impressive stuff, thanks for the links. 24% from wind ATM.

Less than 30 minutes ago, it was 24%. Now it is 10.9%.

This shows how bloody unreliable wind is.

well, that's because demand has doubled!

what it does show though is that we have the miracle of wind blowing for 2 days straight! (just when demand at the weekend is at it's lowest - the last time this happened looks like it was January!)

so, now half of Didcot is out, who wants to predict the day for lights out?

[TimJMS]

gruffalo said:

With wind being so unreliable a source as we can see from the posts above what I want to understand is how are the fluctuations absorbed by the rest of the grid, can coal and gas power stations modulate there output rapidly and if so can they also modulate the fuel used, or do they running at optimum all the time and waste what is not needed.

I know modulation is possible for times of traditional high and low demand but is it possible on a minute by minute basis and does it really result in a reduced fuel burn?

Gas can be whacked up and down with ease. Dinorwig in Wales can go from nothing to full output in less than a minute.