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Chrisbee (Mechanical) (OP)
12 Nov 10 13:09
I am looking for data that would describe the number of failures or hours out of service units in power plants experience during daily operations, their power production capabilities and efficiencies. Is anyone familiar if this data is made public or not and if so where to find it?

Daily/Monthly/Annual Reports of any kind are of interest.

Best Regards,
Chris  
cranky108 (Electrical)
12 Nov 10 14:05
We don't publish that information, but it is probally available through the open records act.
Helpful Member!  rmw (Mechanical)
12 Nov 10 21:16
That is referred to as availability or availability factor and it is usually a closely held secret by utility companies that are in a competitive market place.

I'd be surprised if you find much information in this area.

rmw
Helpful Member!  lylebrown00 (Mechanical)
13 Nov 10 5:11
This information, in general (with the exception of efficiency), is out there (internet) on an annual basis. At least it is for AU based load power stations.
 Suggest you have a look at some of your local generators websites.

Efficiency is generally mostly constrained by the laws of thermodynamics for a given type of power plant, hence there should be relatively minimal variations between power plants for a given type.
Wikipeadia will provide "general" efficiency values for a given type.

Regards,
Lyle
 
ccfowler (Mechanical)
14 Nov 10 21:06
Chrisbee,

In the US, in the "olden days" when utilities were not in a competitive situation, the information that you are seeking would have been fairly readily available, if you knew where to find it, but now, as rmw indicated, such data will be very difficult to acquire in a meaningful manner.

Data of this sort--no matter how true, accurate, or complete--can very easily be misunderstood or misinterpreted without suitable knowledge, experience, and understanding.  Based on the apparent nature of your posting, I suspect that you are not very familiar with this general topic, and it is likely that you may be at a considerable disadvantage in trying to understand the implications of the data that you are seeking.

lylebrown00 is quite correct in his statement that the laws of thermodynamics control, but detailed differences between plants, the duty cycle for which they were designed, and the duty cycle that they actually experience can have dramatic implications for the plant's efficiency and reliability.  The laws of thermodynamics always control, but that statement applies to all aspects of each plant very dynamically.  No power plant just simply operates at some fixed efficiency.

Power plants normally have service lives of 20, 40, 60 or even more years.  They seldom operate their entire lives in the duty cycle for which they were originally intended.  The operation of some may be dictated by something other than just their electic power output.  As an example, some plants provide steam or hot gases to some external process, and those loads may play a major role in how and when the plant is operated.

You will get much better advice if you state your information needs more clearly.  Also, it is likely that the information that you are seeking may be much better obtained through engaging the services of someone with suitable experience and understanding rather than trying to "find a bunch of information on-line" and trying to draw some conclusions from that data.  On your own, it would be very easy for you to draw very wrong or misleading conclusions from very good data.

Valuable advice from a professor many years ago:  First, design for graceful failure.  Everything we build will eventually fail, so we must strive to avoid injuries or secondary damage when that failure occurs.  Only then can practicality and economics be properly considered.

rmw (Mechanical)
14 Nov 10 22:18

Quote (ccfowler):

They seldom operate their entire lives in the duty cycle for which they were originally intended.

I say that they rarely operate at the duty cycle for which they were originally intended, because that point can only be based on one specific set of conditions and an important one of those conditions is the sink to which they reject the heat, and the state of the heat sink typically changes with ambient condition changes.  Sometimes this occurs over days and months, sometimes it can happen hour by hour and minute by minute.

Any operation off of the original design point produces other than design efficiency, sometimes better, sometimes worse, in my experience, more often worse than better.

If we could just get those plants to run exactly as the engineeer drew them up.......

rmw
ccfowler (Mechanical)
15 Nov 10 0:18
rmw,

I agree completely with your statement as it relates to the designer's and manufacturer's perspective.  From the power generator's perspective, the situation is usually much, much worse.

Perhaps most commonly, a new power plant is built and commences operation as the "latest, greatest, most efficient" one around, and it is operated at near full load (or its most efficient load) for a time--usually a few years.  Then another new "latest, greatest, most efficient" plant is added to the system, and the former "latest, greatest, most efficient" sees less favorable loading patterns, more and deeper (and sometimes with marginally damaging faster ramping rate) cycling.  This pattern repeats over and over.

Sometimes, the newest plant is intended for mid-range or peaking duty, but it is likely to see periods where instead of operating at high loads for limited periods, it will instead operate for days, weeks, or even months at nearly continuous full load operation.

Sometimes, the fuel is changed for economic, availability, or evnironmental reasons, and this introduces other problems:  fuel handling and safety, corrosion, ....

Sometimes, units are operated in some partially disabled mode due to equipment problems (feedwater heater leaks, burner or control troubles, weakened or leaking boiler tubes, failed boiler feed pumps, ...) and only partial output is possible, but usually with significantly disproportionately greater fuel consumption.

Now, just what is the supposed efficiency or reliability of a particular plant?  Looking up some numbers in some kind of summary report is going to lead to some meaningful indications for a particular power plant or type of power plant?  I doubt it very much indeed!

Chrisbee, if you really want to mislead yourself and jump to some absurd conclusions, just continue as your initial posting suggests you intend.  If you want to get some good information and guidance that can be of real value, get some serious, competent help.

Valuable advice from a professor many years ago:  First, design for graceful failure.  Everything we build will eventually fail, so we must strive to avoid injuries or secondary damage when that failure occurs.  Only then can practicality and economics be properly considered.

Chrisbee (Mechanical) (OP)
19 Nov 10 11:48
Thank you all for you feedback.

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