A Design Method of Straight-arc Blade Profile of Annular Nozzle

Abstract

The invention discloses a method used for annular-nozzle straight-line-arc-line blade profile line design of a radial-axial-flow-type turboexpander. The method includes: dividing a blade into two parts of a suction surface and a pressure surface, also dividing a blade profile line of each part into a straight-line segment and an arc-line segment, and utilizing mathematical expressions to carry outcoordinate solving on the straight-line segment and the arc-line segment through programming. According to the method, a Bezier curve is adopted for solving for arc-line segment coordinates to realize smooth transition of the straight-line segment and the arc-line segment, thus geometric curvature continuity of the nozzle blade profile line can be well guaranteed, and more flow losses can be avoided; and in addition, the blade profile line is divided into the straight-line segment and the arc-line segment through programming, the mathematical expressions are respectively used for representation, a design process is simpler, more convenient and faster, and subsequent work processes of machining manufacturing, numerical simulation, optimization design and the like on the nozzle blade profile line are facilitated.

Description

technical field [0001] The invention relates to a method for designing the profile of an annular nozzle vane, in particular to a method for designing the profile of a linear-arc vane of an annular nozzle of a radial-axial turboexpander. Background technique [0002] The turboexpander is the main source of cooling capacity in the cryogenic system, and it is also the core component of the modern air separation plant and cryogenic liquefaction system. Its performance is of great significance to the economy and safety of the entire plant. The main flow part of the turboexpander includes an annular nozzle, a radial-axial flow impeller and a diffuser, wherein the annular nozzle is one of the main flow channels for the turboexpander to generate energy, and the design of the blade profile of the annular nozzle is Turboexpander performance has a significant impact. Straight-arc blades are a type of circular nozzle blades. The blade shape is composed of simple straight lines and arcs...

AI Technical Summary

Problems solved by technology

This geometric modeling method mainly has the following two disadvantages: first, it is difficult to ensure a smooth transition between the straight line and the arc when designing the arc segment through the empirical parameter method, which will inevitably cause more flow loss; The ratio of the straight line segment and the arc segment is selected through the empirical drawing method. The process of modifying the profile line is cumbersome and complicated, which is not conducive to the subsequent work process of blade profile processing, numerical simulation and optimal design.

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