COOLING FLOW DEFLECTORS IN INTERMEDIATE PRESSURE TURBINE MANIFOLD
Publication Date: 2010-Jul-23
The IP.com Prior Art Database
The present invention relates to a cooling air system in turbomachinery. More particularly, this invention relates to airflow deflectors used in the cooling air system in turbomachinery. The airflow deflectors reduce the impingement of the cooling airflow on the High Pressure Turbine (HPT) casing when the air enters the Intermediate Pressure Turbine (IPT) manifold. Additionally, the deflectors promote a more uniform flow of cool air through the IPT manifold and into the HPT casing.
PRESSURE TURBINE MANIFOLD
The present invention relates generally to a cooling air system in turbomachinery, and more particularly to cooling airflow deflectors used in the cooling air system in turbomachinery.
The cooling air system in a turbomachine (e.g., a turbine) utilizes air from the compressor to accomplish several objectives. For example, the cooling air system cools the internal parts of the gas turbine, cools the turbine casing and exhaust frame, controls turbine rotating seal and blade tip clearances, prevents compressor stall, and provides an air supply for air-operated valves.
Of particular interest to the present invention is the cooling of High Pressure Turbine (HPT) components, which are subjected to high temperatures during operation. Referring now to the drawings, particularly to Figure 1, there is illustrated an exemplary turbomachine, including an High Pressure Compressor (HPC), an Intermediate Pressure Turbine (IPT) and an HPT. The HPC has an inlet for compressed air by Low Pressure Compressor (LPC) and Booster that is subsequently compressed through a number of different stages of the compressor, each stage compressing the air to higher pressures and temperatures. While the compressed air is primarily for delivery to combustors where the pressurized air is combined with fuel and combusted to provide hot gases of combustion to the various stages of the turbine, bleed air is typically removed from various stages of the compressor for use as cooling air in the turbine. As is further shown in Figure 1, to cool the HPT casing, cool air from the HPC is carried through bleed pipes to the IPT manifold. Ideally, cool air is spread uniformly through the IPT manifold and then carried through spoolie holes provided on the IPT manifold and into the HPT casing. However, in practice, when the airflow from the bleed pipes reaches the IPT manifold, the air exits from a bleed pipe orifice into the IPT manifold at high velocity and causes local impingement on the HPT casing. This impingement causes high local thermal growth near the bleed pipe exits, as well as increased out-of-roundness of the HPT casing. Consequently, the cool air is not uniformly provided to the HPT casing as is intended.
As a result, there exists a need for an improved IPT manifold design that can uniformly provide cool air to the HPT casing.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 illustrates an exemplary turbomachine according to the present invention.
Figure 2 illustrates an exemplary IPT manifold including an airflow deflector according to the present invention.
Figure 3 illustrates different airflow deflectors studied to determine the most suitable design according to the present invention.
Figure 4 illustrates the computational flow models of the different airflow deflectors illustrated in Figure 3.
The present invention provides a cooling air system in turbomachinery that includes an...