Prediction of gas pulsation of an industrial compressor

The measurement and prediction of gas pulsations are performed along the discharge pipeline of a reciprocating compressor for a refrigerator. A regression based experimental model of the one-dimensional acoustic field is developed. First, the conventional method for gas pulsation measurement and prediction, which separates the incident and reflected wave of acoustic waves traveling in the frequency domain, is discussed. Then, regression based on our proposed simple model, which is able to predict gas pulsation compared to the conventional method, is introduced for the analysis of a reciprocating compressor(The conventional method requires the value of sound speed in the piping line for the reciprocating compressor). A numerical prediction is made for the regression method. Three power spectrum values along the discharge pipeline are used for analysis, and two values are used for verification. Our results are in a good agreement with the conventional method.

一种可消除承印物影响的电流体动力喷墨打印技术

电流体动力喷墨打印技术(EHDP)已广泛应用于直接印刷。然而,现有的EHDP方法,其印刷特性受承印物的影响,且打印线宽由喷嘴的尺寸决定。本文提出的一种EHDP新方法能够消除承印物的影响,并且能够通过控制喷嘴阵列中每个喷嘴的开关来实现对打印线宽的控制。本文检验了EHDP系统的印刷特性,同时证明了喷嘴阵列开关控制的可行性。这种新型EHDP技术可以不受承印物的影响得到稳定的弯月形液面;即使使用同样的喷嘴也能得到不同的线宽。