Cooling method for gas turbines. During periods of high electricity demand, especially during the hot summer months, the power output from a gas turbine engine can drop dramatically. One way to counter this drop in power is by cooling the inlet air to the gas turbine. An increasingly popular cooling method uses high pressure inlet fogging.
The performance of a sample of 67 gas turbines augmented with high pressure inlet fogging was investigated in the Journal of Engineering for Gas Turbines and Power (January 2005). One measure of performance is heat rate (kilojoules per kilowatt per hour). Heat rates for the 67 gas turbines, saved in the GASTURBINE file, are listed in the table. Suppose that a standard gas turbine has, on average, a heat rate of 10,000 kJ/kWh.
(a) Conduct a test to determine if the mean heat rate of gas turbines augmented with high pressure inlet fogging exceeds 10,000 kJ/kWh. Use α = .05.
(b) Identify a Type I error for this study, then a Type II error.
Heat rates listed in table
14622
13196
11948
11289
11964
10526
10387
10592
10460
10086
14628
13396
11726
11252
12449
11030
10787
10603
10144
11674
11510
10946
10508
10604
10270
10529
10360
14796
12913
12270
11842
10656
11360
11136
10814
13523
11289
11183
10951
9722
10481
9812
9669
9643
9115
9115
11588
10888
9738
9295
9421
9105
10233
10186
9918
9209
9532
9933
9152
9295
16243
14628
12766
8714
9469
11948
12414