How to deal with turbine flowmeter when the measured value is unstable?

Turbine flowmeters are impeller-type velocity flowmeters, which are speed-type measurements, that is, the flow rate of the medium in the measuring pipe is used to obtain the flow rate. The rotational angular velocity of the impeller placed in the fluid is proportional to the fluid flow rate, and the fluid flow rate is obtained by measuring the rotational angular velocity of the impeller, thereby obtaining a flow rate value within the conduit. Compared with the traditional flowmeter, there are many advantages. For example, when the turbine is working, it can be sent simultaneously with both pulsed and current flow signals, and the instrument can be used not only for light and convenient but also for display instruments, and the price is also Very low cost to reduce production output costs. Modernization has made the calculation of flow rate more accurate through the advanced use of computers. More importantly, the safety is very high. The level of explosion-proof can generally reach 100% of EXDIIBT6. In addition, the use of the flowmeter can also use the liquid crystal to provide data on the spot, and the display of the screen is very high-definition, and the high reliability is not easily affected by special circumstances such as signals and lightning strikes of the surrounding environment, and the current level of the process is improved. The cost of this signal output tool is greatly reduced. The flowmeter is simple and quick to operate in various temperatures and pressures, and the stability is good. The user can perform complicated equation calculation on the basis of the data value, and can better control the flow data and properly control the production.
The turbine flowmeter consists of a turbine, a bearing, a pre-amplifier, and a display appearance. The fluid to be tested impinges on the turbine blade to rotate the turbine. The rotation speed of the turbine is changed with the change of the flow rate, that is, the flow rate is large, the rotation speed of the turbine is also large, and the rotational speed of the turbine is converted into the electrode of the corresponding frequency by the magnetoelectric conversion device. After the preamplifier is enlarged, it is sent to the appearance of the display for counting and display, and the instantaneous flow rate and the cumulative flow rate can be obtained according to the high number of punches per unit time and the cumulative high number of punches.
The relationship between the meter factor of the turbine flow meter and the flow rate (or the Reynolds number of the pipeline). The meter factor can be divided into two segments, a linear segment and a nonlinear segment. The linear segment is approximately two-thirds of the working segment and its characteristics are related to the sensor structure size and fluid viscosity. In the nonlinear section, the characteristics are affected by bearing friction and fluid viscous drag. When the flow rate is below the sensor flow lower limit, the meter factor changes rapidly with the flow rate. The pressure loss and flow rate are approximately squared. Care should be taken to prevent cavitation when the flow rate exceeds the upper flow limit. The shape of the structurally similar TUF characteristic curve is similar, and it differs only in terms of systematic error levels.
The meter coefficient of the sensor is verified by the flow check device. It does not ask the flow mechanism of the fluid inside the sensor. The sensor is used as a black box. The conversion coefficient is determined according to the input (flow) and output (frequency), which is convenient for practical application. . However, it should be noted that this conversion factor (meter factor) is conditional, and the calibration condition is the reference condition. If it deviates from this condition during use, the coefficient will change. Therefore, the smaller the pressure loss of the turbine flowmeter can be summarized. The larger the range, the more accurate it is.
Turbine flowmeter is a relatively common flowmeter. It is widely used. In the course of use, we sometimes find that the measured value is unstable. Many people feel overwhelmed. Today we will introduce it. What are the reasons for the unstable measurement of the flowmeter?
Reasons 1. Check whether the pipe sections before and after the installation of the flowmeter meet the installation requirements, generally the first ten and the last five, which are straight pipes, which are visible to the naked eye, and cannot appear valves;
The second reason is to check whether the turbine bearing is worn. If the flowmeter is used for too long, the bearing wear will cause the measured value to be unstable;
The third reason is to measure the purity of the medium, whether there is liquid or other impurities in the gas, which will also lead to unstable measurement values, and can be installed by a filter;
Reason 4: Whether the medium flow is stable, whether there is turbulence or high pressure, large or small, if there is any instability, the rectifier can be installed.
Cause five: Check whether there is strong magnetic field interference around; when there is a motor, inverter, strong power and other interference sources near the flowmeter, the solution is to ground the flowmeter instrument or add filter capacitor. If it can't be solved, it should be away from the source of interference.
Cause six, check the sensor, whether the amplifier is faulty;
The above is the common reason for the instability of the measured value of the turbine flowmeter. If there are any of the above conditions, you can refer to the solution. If it still cannot be recovered, it is recommended to find a professional understanding check or return to the factory for repair.

With the prolonged operation of the Steam Turbine power generation equipment, after a long period of start-stop operation, the loss of the equipment gradually increases, which inevitably causes the wear, tear, deformation and damage of equipment components, making the whole operation of the machine threatened by risky factors, and make the unit's operating efficiency significantly reduced, and hence affecting the economic performance of the unit. Therefore, the equipment maintenance is particularly important. However, many users do not have professional technical experience and staff, given that, QNP is dedicated to provide its customers with a full range of unit maintenance and repair services, as well as the upgrading of old units. At the same time, QNP also provide its customers with long-term training and debugging services. QNP can develop tailor-made maintenance program upon its customers requirements, provide direct one-on-one service, and realize life-long service to our users.

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