Improvement Design Of Coriolis Mass Flowmeter

Coriolis mass flowmeter(Coriolis Mass Flowmeter, hereinafter referred to as the CMF),the mass flow parameters which can be measured directly and compared with similar products with high accuracy, good stability. However, China’s Coriolis flowmeter market was monopolized by a few foreign brands, and the price is high.Research analysis shows that the domestic Coriolis flowmeter compared with similar foreign products, in terms of accuracy and stability of a larger gap. Based on the Coriolis flowmeter measurement accuracy and stability requirements. More comprehensive studies and experiments from the principles of vibration measurement signal to drive aspects of control technology. Use the appropriate embedded systems hardware and software algorithms for Coriolis flowmeters improved design. The main work and achievements are as follows.(1)when the existing microbending Coriolis mass flowmeter transmitter signal during the low flow measurement. Measurement accuracy and stability can not achieve the desired effect. To solve this problem, the original signal processing algorithm to make improvements and optimization. By using two stage filtering and Lagrange interpolation method of combining the four "combination algorithm", can filter out noise, realized calculate zero detection.Using the average processing method for processing the obtained data obtained.Make the measurement results with good accuracy and stability.(2) the use of vibration fuzzy PID control method measuring tube. Greatly enhanced the measuring tube vibration interference. Experimental results show that the measuring tube from the start-up to use the traditional PID control amplitude stability is required 13 s, the use of fuzzy PID control method requires only about 4s. Especially when measuring tube fluid suddenly become gas-liquid two-phase flow, the traditional control needs 22 seconds to restore normal vibration, and fuzzy control method requires only 13 s.(3) On the basis of the aforementioned comprehensive research results, developed a flowmeter transmitter. With foreign microbending sensor 15mm caliber matches were empty tube zero testing. And water flow testing laboratories in the experimental platform. Test results show that the transmitter for a long time can have a good zero stability.20:1 rangeability range up to 0.5 in the measurement accuracy.Repeatability reaches ten thousandths. Experimental tests confirmed the improved design of the system after the transmitter can well improve the measurement accuracy and stability microbending type sensor.