电加热器安装位置对分体空调挂机风量与噪声的影响

Effect of the installation position on the air flow rate and the noise level for the split-type air conditioner under the variation PTC layout

采用Fluent软件对不同PTC布置角度下的空调室内机的内流特征进行了2维大涡数值模拟,探讨了PTC布置方位对贯流风叶的进气干扰规律,得到了合理的方位角度。在此基础上,进一步研究了由于PTC布置角度的差异而导致贯流风叶所发出的噪声频谱的变化规律。优化后的布置方案可有效减少涡流和气流的分离,减弱位于50 Hz与380 Hz附近的嗡嗡异声。PTC合理的布置方位为PTC法线方向与重力方向夹角为10°,偏向底座一侧。同时对所研究的PTC布置方案进行了风量与噪声测试。试验结果与数值模拟结论相吻合,表明优化后的PTC安装位置是合理的,可有效改善空调器的声质量和气动性能。

This paper is mainly focused on the study of the effects of different PTC layout configurations on the performance of cross flow fan and the noise grade of the split-type air conditioner, in hoping to find the internal flow characteristics of the split-type air conditioner under different PTC layouts, we have carried out 2D LES simulations of the air current by using a software package known as FLUENT. It is found that the installation angle of the PTC tends to affect the inner flow characteristics of the cross flow fan distinctly. Therefore, improper installation of the PTC would like to block the inflow and make the air inflow more scattering and in turn increase the noise level. It is for this purpose, we have conducted a careful simulation, which shows that it is possible to obtain the noise spectrum of the blades by using a FW - H acoustic model under the optimized layout of PTC. It is also possible to improve the eddy intensity and the separation of the air-inflow if the installation position of PTC can be optimized. For example, when the fan is installed at a noise frequency distribution level at about 50 Hz and 380 Hz with a distinct feature of the noise frequency emitted by the cross flow, the disgusting buzz often comes about and therefore it deteriorates the sound quality of the air conditioner. The peak values of the sound pressure of the aforementioned frequencies should thus be reduced by choosing a better design of installation angle. As a result of our simulation, the rational installation angle of PTC that should be obtained from our simulation is 11 degrees against the vertical line and toward the back part of the air conditioner. Our simulation results have also demonstrated that the experimental data are in perfect agreement with the predicted results of calculation. It has also proved that the sound pressure level tends to decrease by 0.5- 1 dB（A） under the optimized installation angle of PTC at the same flow rate. It is also found that the noise level can be reduced more obviously at a high flowing rate than that at the low air rate under different PTC installation angles, especially, when the rotating speed of the cross flow fan is greater than 1000 rpm.