Hermetic compressor valve robust design assessment

DOI: 10.18462/iir.compr.2024.0647

Sekcia: Reciprocating compressors I

Stav prijatia: Abstrakt prijatý

Autori

Abstrakt

Improving the performance or reducing the noise levels of a hermetic compressor often entails optimizing its discharge or suction reed valve design. However, such endeavors frequently involve conflicting objectives, necessitating a trade-off solution. Amidst switching designs, adherence to a crucial constraint is imperative: reliability. This work aims to utilize the staircase method to experimentally determine the bending fatigue strength of different valve materials while minimizing the number of tests and samples required.
A shaker was employed to dynamically excite the valve at its resonance, with valve displacement continuously measured using a laser sensor. A software was developed to actively regulate the shaker power and frequency, ensuring precise control of displacement within the desired tolerance for each test. The load on the valve undergoes complete reversal with a mean stress of zero, subsequently adjusted to a zero-based approach using Goodman criteria. Testing proceeds until reaching 2 million cycles or valve failure.
Since a real valve is used as specimen, not only the material properties are measured, but also the effect of manufacturing process for this specific design, like the tumbling edge radius. Later, this information is crossed with a specific valve design. To achieve this, FEA is employed to calculate stress and its variability. Material properties, shape, valve fixation position, valve opening, among others are included as variable parameters. A robust design is deemed achieved when the stress distribution is far away from the material strength distribution.

Kľúčové slová

staircase, fatigue, valve, bending, stress