Patent attributes
A large and highly twisted turbine blade for an IGT having a lower span serpentine flow cooling circuit and an upper span serpentine flow cooling circuit connected in series to provide low flow cooling for the blade. The lower span serpentine is a forward flowing 5-pass serpentine, while the upper span is an aft flowing 3-pass serpentine circuit. The last leg of the lower span serpentine and the first leg of the upper span serpentine are both aligned along the leading edge region to provide cooling there. The trailing edge includes lower span exit cooling holes and upper span exit cooling holes in which the lower span exit holes are connected to the first leg of the lower span serpentine and the upper span exit holes are connected to the last leg of the upper span serpentine. All of the cooling air from the lower span serpentine circuit that does not flow out the lower span exit holes flows into the upper span serpentine circuit to provide low flow cooling with the lower span cooled before the upper span.
