rcw retired EE
Electrical
- Jul 21, 2005
- 907
On a combined cycle power plant proposal, a vendor provided steam turbine and gas turbine generator ratings versus ambient air temperature charts that had different curves for "IEEE Class B Rise, 0.85 pf" and "IEC Class B Rise, 0.85 pf". It looked like the ANSI/IEEE curve had about 30C difference in the allowable temperature rise at the same MVA. For example at 250 MW, 0.85 power factor, the IEEE curve is 0C ambient air, but the IEC curve shows 32C ambient air. The curves take into account the approach temperatures for the fin-fan air to water cooler and the water to hydrogen heat exchangers on the generator.
What is the reason for the 30C difference in the allowable temperature rise bewteen the IEEE C50.13 and the IEC standard (# unknown). Is it hot spot allowances, different test methods or different definitions?
What is the reason for the 30C difference in the allowable temperature rise bewteen the IEEE C50.13 and the IEC standard (# unknown). Is it hot spot allowances, different test methods or different definitions?