Stem design method of quick ball valve

Abstract

The invention discloses a valve stem design method of a fast ball valve, which is characterized in that a corresponding theoretical model is established based on the occurrence process of the valve stem under a dynamic stress load, so as to obtain the corresponding dynamic load safety evaluation value as the finite element strength structural stress Analyze the theoretical parameter values ​​of the design evaluation software. The invention provides a valve stem design method of a fast ball valve, which solves the problem that the current general material mechanics calculation formula is only designed and evaluated for the static load stress intensity of the valve stem material and structure, and is not suitable for high-frequency dynamic load conditions of the fast ball valve. By providing a simple, reliable and efficient theoretical calculation design method to reduce the designer's early design cycle and reduce manufacturing costs, it does not affect the overall performance of the fast ball valve.

Description

technical field [0001] The invention relates to the field of ball valve design. More specifically, the present invention relates to a valve stem design method of a quick ball valve used when designing the dynamic structure of the valve stem transmission chain of the quick ball valve in a wind tunnel test system. Background technique [0002] In the aerospace hypersonic wind tunnel test system, the fast ball valve is an important control device of the main gas supply system, which requires high pressure (42MPa), large opening and closing pressure difference (40MPa), fast opening (≤1s), Due to the functional characteristics of opening and closing, higher design requirements are put forward for the structure of the quick ball valve stem. [0003] In the actual test, the twisting direction of the fast ball valve and the ordinary ball valve is just opposite to the opening failure. After research, it is found that at the beginning of the opening process of the fast ball valve, th...

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Problems solved by technology

[0003] In the actual test, the twisting direction of the fast ball valve and the ordinary ball valve is just opposite to the opening failure. After research, it is found that at the beginning of the opening process of the fast ball valve, the actuator performs work on the valve stem with a high initial acceleration. Since the valve stem and the ball adopt mechanical When the end is opened, due to the limit effect of the mechanical structure, the valve stem "instantaneously" stops, and the acceleration becomes 0, and the ball connected to it rotates through 90° acceleration to obtain The large kinetic energy angular velocity acts on the valve stem, causing the valve stem to be subject to a large impact load, which in turn causes reverse torsion failure and deformation, which reduces the overall transmission positioning accuracy of the equipment, and in severe cases, an accident of transmission chain failure occurs

[0004] At present, in order to solve this problem, the common practice is to increase the safety factor of the valve stem transmission chain, improve the strength grade of the valve stem material and heat treatment methods to ensure the application performance of the quick ball valve stem. The disadvantage is that the overall structure of the valve is enlarged, resulting in high cost of installation space on the project site; the corresponding bearing friction torque increases after the diameter of the valve stem increases, which also results in unreasonable selection of actuators for fast ball valves and redundant waste.

[0005] Furthermore, the current general material mechanics calculation formula only designs and evaluates the static load stress strength of valve stem materials and structures, and is not suitable for the safety evaluation of fast ball valves under high-frequency dynamic load conditions, while the finite element strength structural stress analysis It is a relatively advanced design evaluation software, but it is limited to the theoretical level of the operator and the performance of the software carrier equipment. Therefore, in this type of project, a simple, reliable and efficient theoretical calculation design method is needed to reduce the designer's early stage. Design cycle, reduce manufacturing cost without affecting the overall performance of the quick ball valve