control curve constant

S

Thread Starter

salman

Dear all
i found these control constants in one performance test. i need an explanation for them.

can i use the for example to evaluate any parameter, for example can they used to identify my firing temperature whether it 2035 F or 2055 F<pre>
Description Units Value
Control Curve Type Xc 7
Control Curve Slope deg F / Xc -23.923
Control Curve y-interc F 1323.60
Exhaust Temperature F 1100.000
TCD or CTIM Bias deg F / deg F 0.000
TCD or CTIM Offset F 0.000
IGV Bias deg F / deg 0.000
IGV Offset deg 0.000
Region 2-3 Slope deg F / Xc -23.923
Region 2-3 y-intercep F 1323.601
Region 2-3 x-intercep Xc 15.847
Region 3-4 Slope d eg F / Xc -23.923
Region 3-4 y-intercep F 1323.601
Region 3-4 x-intercep Xc 64.000</pre>
 
B

Bob Johnston

These constants are for calculating the max. allowable Exhaust Temp (TTRXB). Take a look in your Control Specification, there should be a good explanation of the calculation there. The calculation may have been demonstrated for a Performance run but it is not specifically for that, really for the everyday calculation of capability.
 
M

Miguel Sernas

Hello, these constants describe the relationship between exhaust temperature and compressor pressure ratio at baseload.

Plot the values of Exhaust temperature in the y-axis and compressor pressure ration the x-axis.

Each region is a different line. So for region 2-3 slope means the slope of the curve; intercept with the y-axis means the intercept with the y-axis. Use the simple y = mx + b where y will be your exhaust temperature, x your compressor pressure ratio and b is the y-intercept.

With this relationship, you should be able to plot your exhaust temp. Vs compressor pressure ratio.

This will help you at baseload to know if you are running in the right control curve by comparing TTRXP and TTXM, they should match exactly at baseload otherwise contact me and we can help. =)

Hope this helps.
 
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