Patent Application
20160053767
The disclosure relates generally to airflow inlets, and more particularly, to an airflow inlet bellmouth having a coating thereon to reduce a surface roughness thereof, and a related method.
Airflow inlets to industrial devices such as gas turbine compressors include a bellmouth component that acts to collect, initially compress, and direct an airflow, e.g., toward a turbine portion of the compressor. In many settings, during operation, static pressure is measured in the inlet bellmouth component, for example, using a Pitot method. The static pressure may be used to determine a mass flow rate of air which is used to better control operation of other components, for example, controlling a firing temperature of a combustor of a gas turbine. In another example, mass flow rate may be used to determine a compressor operating limit degradation.
One challenge in determining the static pressure in the inlet bellmouth is that an inlet annulus area where the pressure is measured must be accurately known. However, conventional inlet bellmouths are oftentimes manufactured as a cast component having significant variation and large tolerances in an internal surface thereof, i.e., they are uneven or rough. The variations and large tolerances in the inlet bellmouth diminish static pressure measurement accuracy by a static pressure sensor system, and thus hinder accurate mass flow rate calculations. In order to address this situation, conventionally, a sampling of inlet bellmouth(s) is/are analyzed after manufacture and a calibrated correction factor is determined and employed in the static pressure calculation for all of the inlet bellmouths. However, since there are large variations between inlet bellmouths that are created, and the inlet bellmouth's internal surface may change over time, use of a correction factor based on a sampling is not ideal. While casting or machining an inlet bellmouth with less surface variation is feasible, it is generally not cost effective. Such an approach to manufacturing also does not correct the problem for previously installed inlets.
A first aspect of the disclosure provides an airflow inlet, comprising: a bellmouth component having a substantially uneven internal surface; and a variable thickness coating in a measurement annulus region of the substantially uneven internal surface, the variable thickness coating configured to present a more even internal surface than the substantially uneven internal surface, wherein the measurement annulus region includes only an annulus about the internal surface of the bellmouth component.
A second aspect of the disclosure provides a bellmouth component for an airflow inlet, the bellmouth component comprising: a static pressure measurement annulus region configured for measuring a static pressure by at least one sensor system, the measurement annulus region including a variable thickness coating on a substantially uneven internal surface of the bellmouth component in only the measurement annulus region, the variable thickness coating configured to present a more even surface variation than the substantially uneven internal surface within the measurement annulus region.
A third aspect of the disclosure provides a method comprising: accessing a bellmouth component of an airflow inlet, the bellmouth component including a substantially uneven internal surface; and applying a variable thickness coating to a measurement annulus region of the substantially uneven internal surface of the bellmouth component to create a more even internal surface, wherein the measurement annulus region includes only an annulus about the internal surface of the bellmouth component.
The illustrative aspects of the present disclosure are designed to solve the problems herein described and/or other problems not discussed.
These and other features of this disclosure will be more readily understood from the following detailed description of the various aspects of the disclosure taken in conjunction with the accompanying drawings that depict various embodiments of the disclosure, in which:
It is noted that the drawings of the disclosure are not to scale. The drawings are intended to depict only typical aspects of the disclosure, and therefore should not be considered as limiting the scope of the disclosure. In the drawings, like numbering represents like elements between the drawings.
As indicated above, the disclosure provides an airflow inlet having a coating in a measurement annulus region of a bellmouth component. Referring to
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In another embodiment, bellmouth component 104 for airflow inlet 100 may include a static pressure measurement annulus region 130 configured for measuring a static pressure by at least one sensor 118. Measurement annulus region 130 includes variable thickness coating 102 on substantially uneven internal surface 120 of the bellmouth component 104 in the measurement annulus region. Variable thickness coating 102 is configured to present a more even surface 132 variation (see
It is emphasized that in addition to the time bellmouth component 104 is initially manufactured, variable thickness coating 102 may be applied at a variety of points in time across the life of bellmouth component 104. In particular, variable thickness coating 102 may be applied, according to an embodiment of a method of the invention, by accessing bellmouth component 104 of an airflow inlet, e.g., in the field and after some time of use by removing any protective filters, shielding, etc., at an open end of bellmouth component 104. Variable thickness coating 102 may be applied to measurement annulus region 130 of substantially uneven internal surface 120 of bellmouth component 104 to create a more even internal surface 132. As noted herein, the applying may include any appropriate method for the material used, e.g., spraying, infusion, injection, deposition, etc. Where a correction factor is employed that is initially based on substantially uneven internal surface 120 to determine a static pressure (and/or a mass flow rate) of airflow 114 through bellmouth component 104, the correction factor can be revised for determining a static pressure based on more even surface 132. In the above-described fashion, variable thickness coating 102 can be applied to previously installed and used bellmouth components without replacement and, in most cases, without removal of the component.
While
While the use of variable thickness coating 102 has been described herein as making bellmouth component 104 dimensionally consistent for the purposes of measuring static pressure, it is understood that coating 102 may act to improve other measurements, thus allowing more accurate control of any industrial component that relies on the particular measurement.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiment was chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.
