研究紹介
47フィーダーバルブにおけるチャタリングノイズの低減
2003 年 11 巻 2 号 p. 113-123
詳細
2003 年 11 巻 2 号 p. 113-123
Efficient water feeders are a critical element in steam and hot water boiler systems. Overfeeding will cause the system to flood; not enough water will cause boiler damage due to overheating. Likewise, any other interruptions in a smooth feeding operation are not tolerated by the end user. As the dominant market leader in the manufacture of boiler controls, McDonnell & Miller's (M&M) mechanical water feeders are an integral part of heating systems world wide.
Field reports of "chattering" energized M&M to apply the Taguchi Robust Design technique in order to enhance the design and make it most robust against the field noise conditions. Chattering refers to a condition that manifests itself when the feeder valve is slightly open or slightly closed. A system harmonic is created, resulting in a loud, rolling noise through the heating pipes. This noise is considered by customers to be a significant nuisance and must be minimized or eliminated.
A dynamic Taguchi L18 experiment was performed. The experiment analyzed the level effects of six (6) control factors and three (3) noise factors. The "Zero Point Proportional" equation was used for the analysis. The inlet pressure to the feeder valve and cross-sectional flow area are utilized as dynamic signals. The flow rate through the valve is used as the response. The SNR (Signal-to-Noise ratio) of the present design is -8.87 dB and the predicted SNR for the optimum design is -2.97 dB. The SNR for the confirmation run is -4.25 dB. Experiment results showed a SNR ratio gain of 4.63 decibels compared to our present design. This indicates that a significant improvement to the chattering problem could be potentially achieved.
