Ma Yuzhen

The denoise design of pressure reducing control valve in thermal power plant

Noises are common during operation, so the noise analysis and noise removal is necessary. High level vibration and noise may lead to the control valve fully open. After analyzing the causes of vibration and noise, the noise estimation formula put forward by Masonneilan company is used to estimate noise, and two measures of pipeline modification and valve internal constitution reform are proposed. In the valve internal structure reform design, the reform is mainly focused on designing balance spool, designing and installing sleeves and limiting spool motion. The pressure experiment results show that the performance of control valve is better.

Application of 3G technology in mariculture dynamic monitoring

At present, many shortcomings still exist in mariculture dynamic monitoring of our country. Given the current extensive applications of 3G technology and its advantages, this paper applies 3G technology to mariculture dynamic monitoring and puts forward a dynamic monitoring system based on 3G technology of mariculture. Parameters such as the salinity, potential of hydrogen (PH) value, temperature are as monitoring indexes in this paper. And the scheme of the system structure is put forward, it includes data acquisition module, data communication module, database module and user terminal module. The system provides many conveniences such as data collection, transmission, processing, storage and feedback control for users. So the users can get real-time data and monitor the mariculture effectively. It is in favor of the development of China ocean economy.

Surface defect detection based on capacitive probe for bearing ball

According to the characteristics of the bearing ball surface defects, the capacitance probe detection system was adopted for measuring. Due to the sensitive measurement area of capacitance sensor is certain sizes of equivalent plane, the average effect eliminates the influence of microcosmic geometric feature. According to the standard of the ball bearing parameter changes, we put forward a dynamic threshold algorithm for defect detection. The algorithm combined the whole characteristic value with local one, by using differences between the normal surface measurements and defective surface detection to find defect. And to Φ 18.2562mm stainless steel bearing ball as an example, the normalization processing was done for data measured along the meridian, through the data distribution of probability density function, it intuitively shows the measurement value distribution characteristics of qualified bearing ball and defective one, so we can do effective separation for normal data and defect data.

A new method for the analysis of temperature-dependent resistances and inductances of multiconductor cable

The whole mechanical test procession, especially transmission cable is effected evidently by environment temperature fluctuation. So of particular interest in the paper is to discuss the resistance and inductance parameters of multiconductor at environment of changing temperature. A new approach with the given formulas is presented to calculate electric parameters using finite element method. And then, the temperature-dependent characteristics of resistance and inductance are obtained, which are agreed with the result obtained by energy method. The change of equivalent current density for multiconductor also highlights the parameters change when proximate effect is considered. The result is shown that the temperature-dependent parameters bring more important responses on the terminal of circuit network containing certain deviation. It is shown that. For the first time, results are shown for the lossy transmission cable with temperature-dependent parameters characteristic, which are used to quantify the main practical engineering.

Compensation of the optical fiber sensor based on the surface quality detection for steel balls

This paper introduces the domestic and international steel ball surface defect detection status, a fiber optic sensor with multi-ring receiving fibers was used for the detection of surface defects on steel ball. According to the different mechanism of defects, the different mathematical models were adopted to compensate the displacement-related defects and roughness-related defects on steel ball, so as to achieve the purposes of accurate judgments and distinguish defects.