Numerical simulation and reduction of balance valve noise based on considering quadrupole and dipole in different frequency bands

Abstract

The natural gas balance valve is an important part to control the flow of natural gas and use it safely. When the pressure before the valve is close to the upper limit, there will be a strong noise at this time. Aiming at the problem that the aerodynamic noise of the balance valve with large pressure drop is difficult to predict accurately, a new numerical simulation method of aerodynamic noise considering quadrupole and dipole in different frequency bands is proposed. The LES numerical method is used to obtain the pressure fluctuation and velocity fluctuation information. Taking the pulsation information as the source term, the dipole and quadrupole noises are solved respectively. The results show that the sound pressure level in the low-frequency band is mainly dominated by both quadrupole noise and dipole noise, while in the higher-frequency band, it is mainly dominated by dipole noise. The total sound pressure level is obtained by considering the quadrupole and dipole noises in different frequency bands, and it does not exceed 5% with the experimental error. Aiming at the problem that the total sound pressure level exceeds 85 dB(A) when the pressure drop is 0.30 MPa, the noise numerical simulation of the balance valve equipped with the noise reduction sleeve is carried out, and the hole diameter and hole distance of the sleeve are optimized. The total sound pressure level of the balance valve with optimized noise reduction sleeve is lower than 85 dB(A).