Steam Turbine Operating Data 1

[hd167]

As I know power plant operating data (thermodynamic steam turbine, steam cycle data) are stored over a longer period of time (some months or longer). I am referring to a power plant with no on-line performance monitoring system (only the normal DCS). Asking many plant operators about what happens with these historical data they could not tell me. Apparently these data are no more used.

Is it not possible to analyse these data off-line with a special performance monitoring software to find out how the performance of the steam turbine generating set or boiler plant changed over a period of time.

Please let me know your experience and the type of software you use.

 

[TD2K]

What data is available?

Given inlet pressure and temperatur and outlet pressure, you can determine both the theoretical steam rate and the actual steam rate. That would allow you to track the turbine's efficiencies, all other variables equal.

What are you considering using this data for?

 

[hd167]

All measured data (pressures, temperatures, flows) of the steam turbine (live steam, bleede, exhaust), condenser, LP-preheaters, deaerators, HP-preheaters, boiler, etc. are available. With individual data one can calculate the thermal efficiency of the turbine and the whole cycle. But this would be a singular value. The problem is that a huge amount of data corresponding to different load points is available. How can these data be analysed? By calculating an average value of each data and using it as inputs for an off-line performance monitoring software (Gatecycle, Proates, ...)?? But this would be rather complicated if done manually.

The aim of this analysis should be the tracking of long term thermal efficiency and diagnosis of deficiencies (deposits on the blades, fouling of heat exchangers, etc.).

 

[poetix99]

The concept of steam turbine "trend monitoring" is well-established (as you seem to know). If you want more background on the concepts, try K.C. Cotton's book "Evaluating and Improving Steam Turbine Performance"

My copy of the book is not with me at the moment; try these threads for more related info about the book, and these considerations in general:
thread605-47965
thread666-47234
thread626-3561
The forums associated with those threads have other discussions that might be useful to you.

Are you merely asking about how to "massage" the data for monitoring s/w?

One of the keys to an elementary approach to trend monitoring is that the trending must occur at comparable conditions (power, steam conditions,...). The more sophisticated the s/w, the more that variations of operating conditions can be accounted for, but in general you must come back to some (arbitrary) reference point.

DCS data could be quite useful in developing some information about the turbine performance trends. If you can get it into a spreadsheet-compatible format, I can easily imagine creating various appropriate sorting parameters in order to eliminate as much "undesireable" data as possible.

You could go a long way on your own with Excel and some downloaded steam properties (try

http://www.cheresources.com

, or search on "water97_v13&quot

Aside to TestDog2K: exhaust temperature is also required before ACTUAL efficiency (steam rate) can be determined. (I know that you know better...)