Application of the hottest digital high-tech in ve

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Application of digital high-tech in fan monitoring system of Fanliang Yuwei et al Abstract: main structure can detect the yield strength, tensile (compression, bending) strength, elongation, non proportional strength Re and its work principle about monitoring system of running parameter variation for high in performance and intelligent fan are e effect of energy saving obtained by using this system is pointed intrinsic benefit resulting in its monitor is evaluated

key words:fan computer monitor I. overview at present, domestic fans often have long-term inefficient operation, and even surge and bearing damage due to improper type selection, poor installation and commissioning, and unreasonable adjustment of operating points. Therefore, combined with the actual situation of the mine and Shenyang ShenHan electronic equipment factory, a high-performance and intelligent fan operation parameter monitoring device is developed. The device can measure the voltage, current, power, air pressure, air volume, bearing temperature and other working conditions parameters of the fan in real time, and all parameters are displayed by the digital display. The corresponding characteristic curves of flow, pressure, power and efficiency are displayed on the color display screen. The corresponding changes of fan operating condition points can be dynamically tracked from the fan characteristic curve interface on the display screen. In order to understand the operating state of the fan and adjust the working condition of the fan in time, which provides a scientific guarantee for preventing the occurrence of surge accidents and ensuring the efficient and safe operation of the fan. 2、 Main technical parameters 1 Motor voltage: 0 ~ 7000 V

2 Motor current: 0 ~ 300A

3 Power factor: 0 ~ 1.00

4 Fan pressure: 0 ~ 7000 PA

5 Fan flow rate: 0 ~ 100m/s

6 Fan flow: 0 ~ 10 000m3/min

7 Instrument accuracy: 1% III. system structure and working principle the fan operation parameter monitoring system is a monitoring system based on the requirements of international GB "fan field test" and the mathematical model established with reference to its field test examples

1. Calculation of fan flow, pressure, shaft power and efficiency

calculate the flow Q0, static pressure pst0, shaft power N20 and efficiency of the fan under the standard state with the total pressure, static pressure and dynamic pressure in the fan pipe η 0, the formula is


static pressure pst0= [pst1- (a3/a1) 2( ρ 1/ρ 3) Δ P3〕

× (n0/n)2 ρ 0/ρ 1

shaft power

efficiency η 0=(Q0Pst0/6 × 104N) × 100%

ρ 3=P3/RT3=(Pa-Pst3)/288.5(273+t3)

Δ P3=(P3-Pst3)、Pst3、 ρ 3. A3 refers to the dynamic pressure, static pressure, density and sectional area of the gas at the fan flow measurement section ()

Pst1、 ρ 1. A1 is the static pressure, density and sectional area of the gas at the fan inlet section ()

n0、n、 ρ 0 (1.2), PA, T1, 3 (273+t1, 3), R (288.5) are the synchronous speed of the motor, the measured speed, the standard atmospheric density, the ambient atmospheric pressure, (), the absolute temperature of the gas in the section () and the gas constant respectively

n refers to the input active power of the motor

2. The cabinet of the hardware part

device adopts 19 inch standard industrial control cabinet. The hardware part is composed of industrial control microcomputer, single chip computer, various parameter sensor transmitters, signal conditioning circuit, LED display panel, input and output interface circuit and switching power supply

(1) pressure sensor transmitter

the micro differential pressure sensor with automatic temperature compensation, high sensitivity and low drift is selected for the measurement of flow and pressure. The pressure signal sent by the sensor is adjusted by the transmitter to a 4 ~ 20mA current output in line with international standards. There are three groups of pressure sensor transmitters, which measure the dynamic pressure, static pressure and surge measuring points of the fan respectively. The measured data is used to calculate the flow rate, flow and wind pressure through the lower computer and make surge prediction

(2) electrical parameter transmitter

electrical parameter transmitter is divided into voltage transmitter only after 1 year, current transmitter and three-phase active power transmitter. Its output signals are 0 ~ 5V standard signals. After connecting the transmitter with its corresponding transformer and connecting the power supply, the corresponding parameter values can be obtained, and the power factor and fan operation efficiency can be calculated

(3) temperature measurement circuit

the temperature measurement current is designed to configure PT100 (pt46, cu50 can also be used), and its analog input channel has a total of 16 channels (8 channels for fan 1 and fan 2 respectively). After conditioning, the voltage signal of the temperature sensor is sent to the a/d converter, and then the corresponding temperature value can be obtained through single-chip microcomputer operation

(4) motherboard

the motherboard adopts a single-chip computer system with 8031 as the core, which is small in size, strong in anti-interference ability, simple in programming and reliable in long-term operation, and suitable for real-time control. Its analog input channel has 32 bits in total. The analog-to-digital converter adopts the 12 bit high-speed conversion chip AD574 produced by American ad company, and its analog signal input range is dc0-10v. There are 8 groups of LED drive circuits in the output part of the system, which can send all operating parameters to the LED display panel at the same time. Eight relays can participate in alarm and control, and RS-232C interface circuit for communication with microcomputer is also set

(5) industrial control microcomputer

microcomputer is mainly used to depict the performance curve of the fan and display the working point. Users can monitor the operation of the fan, which is a relatively advanced hydraulic universal experimental machine, and adjust the fan blade angle according to the area where the working point is located, so that the fan can operate in the high-efficiency area and prevent surge accidents at the same time. ② press the sample clamping key, and the upper collet of the instrument starts to run upward to move the clamping length. When the upper collet reaches the set clamping length, the electromechanical stops running to the purpose of high efficiency, energy saving and safe production

the main configurations of microcomputer include: CPU, memory, hard disk, 3.5-inch floppy drive, 14 inch display, industrial control keyboard and communication

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