Ru Jian Ma

Design and Tests of Wireless Network for Heat Metering System

A wireless self-organizing network for heat metering system is designed based on ZigBee in this paper. XBee-Pro module is used for terminal nodes. Such nodes set up wireless mesh network, collecting heating meter data on one hand and realizing remote transmission of data though setting up mesh network with Router and Coordinator. The test is showing that wireless network system based on XBee-Pro module is convenient to use, reliable to transmit data and applies to collect spot discrete data and wireless transmission and meet requirement of heating meter remote transmission, realizing informatization and automation of controlling and monitoring of heating meter system.

Design of Wireless Automatic Meter Reading System

Community property management in metering and charging of resource and energy consumption, such as water, electricity and gas charging are a time-consuming, laborious, tedious and monotonous work. It also needs a large amount of computing and the computing requires high accuracy because the dispute will affect the social security easily. The current used meter reading and charging systems for resource and energy consumption of household are analyzed in this paper. The wireless automatic meter reading and charging systems are also discussed. A design scheme is proposed based on short-range wireless meter reading communication technology. The combination of CC1100 radio frequency module and GPRS network is used in the scheme. The system has the characteristics of low in price, simple in structure and good stability.

Numerical Simulation and Analysis of Internal Flow Field for Control Valve Inlet Blocking Fault

The internal flow field and the noise of inlet blocking fault and trouble-free for control valve are numerical simulated by CFD. The study shows that it is a greater influence on the internal flow field by inlet blocking, the back-end of stemming appears reverse flow, and it make vortex, the phenomenon of the two fluids mixing is appeared below the valve core. The tremendous noise is appeared in the blocking, and it increases the noise of the surrounding area.

Study on Flow Characteristics of Valve Inlet Blockage

The flow characteristic and differential pressure-flow of inlet blockage fault and trouble-free for control valve are numerical simulated by CFD. The study shows that relative gain of flow characteristic curve for inlet blockage is increased, and it enhances the influence on fluctuation to flow change. The flow is less than the trouble-free at the same pressure, and with the increase of the differential pressure, flow difference of comparing with trouble-free increases gradually.

Research on Dynamics Measurement of Piezoelectric Sensor Based on PVDF Films

A new type of upper and lower cover support structure piezoelectric sensor based on PVDF films is designed in terms of piezoelectric effect. Mechanics and mathematical models are established according to the structure of the sensor. The natural frequency of the sensor is derived finally. The natural frequency of the sensor is verified to meet the requirements of dynamic measurements by using theoretical calculations and simulations. The effectiveness of the calculating method is indicated.

Design and Analysis of Force Sensor for Condition Monitoring System of Ball Cold Heading Forming

In order to solve the forming defects in the steel ball cold heading process, a novel force sensor which chooses the PVDF piezoelectric films as force-sensing elements is designed. The advantages and disadvantages of piezoelectric force sensor on measurement of the cold heading force are compared with existing force sensors. By using FEM, sensor’s linearity and the structure size are analyzed. Compared with the traditional sensor, this structure is more reasonable. The presented PVDF piezoelectric force sensor has wide frequency range, good dynamic performance, and can realize dynamic measurement.

Research the Internal Flow Field of Valve Stem Leakage

Establish valve stem leakage flow channel model, apply the CFD numerical simulation the internal flow field and noise. Research shows that it is no effect on the valve inlet and outlet flow field when the valve stem leakage. It is no effect on the valve body flow field and the greatest influence the balance cavity flow field. Changing the flow direction of the balance cavity and produce left vortex, it break left vortex of right part. New tremendous noise sources appear the balance cavity and improve the noise of surrounding areas.

Simulation and Analysis the Internal Flow Field of Control Valve Bonnet Leakage

Apply the CFD numerical simulation the internal flow field and noise when the control valve is bonnet leakage and trouble-free. Research shows that bonnet leaking has almost no effect on valve inlet and outlet flow field. It is an impact on valve body flow field and the greatest impact on balance cavity. It changes the flow direction of the balance cavity and produces right vortex, in balance cavity where originally without noise, the tremendous noise appeares and improves the noise of the surrounding area.

Research on Grinding Characteristics of Ultrasonic Aided Grinding

Experimental study of radial ultrasonic vibration aided grinding of sintered Nd-Fe-B permanent magnetic material was conducted contrasted with traditional grinding. The effect on normal grinding force of grinding parameters was analyzed respectively in the two grinding processes. Experimental results indicate that the discontinuous grinding mechanism caused by ultrasonic vibration is the main factor that reducing the normal grinding force. The process of radial ultrasonic vibration aided grinding is especially suitable for shape machining of sintered Nd-Fe-B permanent magnet.

Design of Wireless Monitoring System of Semi-Lean Pumps

A design scheme is proposed in this paper for wireless monitoring system of semi-lean pumps based on ZigBee and XBee-Pro module. The XBee-Pro module is placed inside the semi-lean pump to monitor the working parameters. The monitoring data is transmitted to the computer in the monitoring and control center by means of ZigBee through routers and coordinators. System tests show that wireless network system based on ZigBee and XBee-Pro module is convenient to use and reliable to transmit monitoring data.