Introduction: The 22nd Multinational Instrumentation Conference and Exhibition (MICONEX 2011), organized by the China Instrument and Control Society, was held at the China International Exhibition Center in Beijing from August 30th to September 2nd, 2011. Professor Zhang Tao from the Automation College of Tianjin University observed and analyzed the flow meter.

The 22nd Multinational Instrumentation Conference and Exhibition (MICONEX 2011), sponsored by the China Instrument and Control Society, was held at the China International Exhibition Center in Beijing from August 30th to September 2nd, 2011. More than 500 Chinese and foreign companies from 20 countries and regions participated in this year's MICONEX. Nearly 10,000 kinds of instrument and meter products were exhibited, including industrial automation instrumentation and control systems, sensors, industrial automation information technology and software, scientific instruments, electronics and electricians. Measuring instruments, instrument materials and components, instrumentation, process equipment and processing equipment. According to our statistics, there are a total of 54 flow meter exhibitors, including 18 foreign and 36 domestic. There may also be individual missing manufacturers in the statistical process. Siemens, ABB, GE, KROHNE, Yokogawa and other foreign flow instrument manufacturers came to the show. The exhibited flowmeters of various types of exhibitors are shown in Table 1. The overall number of exhibitors is decreasing, probably due to the rapid development of the Internet. Due to the advantages of convenient and quick Internet sales, it has been increasingly recognized by people. The traditional exhibition mode has played a weak role, but the exhibition is still the best way of irreplaceable physical display.

The characteristics and highlights of exhibitors

(1) Electromagnetic Flowmeters At this exhibition, 25 manufacturers exhibited electromagnetic flowmeters, which accounted for 46% of the total number of exhibitors. Among them, there are 6 foreign manufacturers, accounting for 33% of the foreign manufacturers; 19 domestic manufacturers, accounting for 53% of the domestic exhibitors.

1) Two-wire electromagnetic system Shanghai Azbil Control Instrument Co., Ltd. exhibited MagneWTwo-wirePLUS is a two-wire electromagnetic flowmeter with low power consumption. The sensor diameter ranges from 2.5 to 200mm. The measurement accuracy is ±0.5%. The minimum conductivity of the measurable process fluid is 10 μS/cm. With electrode status diagnostics, you can diagnose the status of empty tubes or scale on the electrodes.

Shanghai Yokogawa Electric Co., Ltd. exhibited a dual-frequency excitation two-wire electromagnetic flowmeter. The sensor diameter ranges from 25 to 100mm. The measurement accuracy is 0.5% of the flow rate. Measurable fluid conductivity ≥ 10μS/cm. With electrode fouling detection. In order to avoid flow noise, the inner PFA surface is mirror finished.

2) Battery-powered electromagnetic Cologne Measuring Instruments (Shanghai) Co., Ltd. exhibited a battery-powered electromagnetic flow meter WATERFLUX3070. Diameter range DN25 ~ DN600. Accuracy up to ±0.2% of measured value 0.5mm/s. Its own battery life can be up to 15 years. Measure bidirectional flow. The specially designed measuring tube shape, as shown in Fig. 1, eliminates the need for forward and backward straight sections. Built-in reference electrode, no grounding ring required. Buried sensor (IP68 grade).

In addition, the Optiflux series electromagnetic flowmeter exhibited by Cologne has more than ten intelligent diagnostic functions such as electrode surface and pipe deposits, electrode corrosion, bubbles and solids in the medium, and fluid state. The exhibition site demonstration device for bubble diagnostics in media was also specially produced.

ABB exhibited the battery-powered electromagnetic flowmeter AquaMaster3. Diameter range DN15 ~ DN600. Accuracy 0.5. Its battery life is 10 years. A specially designed inner octagonal measuring tube with a reduced diameter is shown in Figure 2. No need to straight forward and backward sections. Use 4 electrodes. Both sensors and transmitters meet the IP68 protection rating.

3) Capacitive electromagnetic flowmeter Shanghai Yokogawa Electric Co., Ltd. exhibited the ADMAGCA capacitive electromagnetic flowmeter. It uses non-liquid-type electrodes. Electrodes on the outside of the alumina ceramic liner can detect the electromotive force generated by the fluid through the capacitance of the tube. No need to worry about leakage of fluids, and it is not affected by viscous fluids or high-strength grouts that can measure corrosive and abrasive media. Measuring tube diameter range 15 ~ 200mm. The minimum conductivity of the fluid to be measured is 0.01μS/cm (range of 15 to 100mm). The measurement accuracy can reach ±0.5% of the flow (path range 25 to 100mm).

The appearance of the 4-20mA two-wire electromagnetic flowmeter brings great convenience to the application in the process control field. Battery-powered electromagnetic flowmeters can be easily used in the tap water industry, and they are well-protected and can work normally underwater. To satisfy the measurement of the slurry, a dual-frequency excitation method or a capacitive electromagnetic flowmeter was adopted.

(2) Micro-flow measurement instruments With the development of industries such as fine chemicals, semiconductors, pharmaceuticals, and medical devices, more demands were placed on the measurement of micro-flows. At the exhibition, various manufacturers were exhibited based on various The principle of small flow meter.

1) Bronkhorst, The Netherlands

The Coriolis Force Flowmeter miniCORI-FLOW for small flow measurement and control is shown in Figure 3. The smallest measurable flow range is 0.4 to 20 g/h. For the liquid medium to be measured, the measurement accuracy is ±0.2%Rd; for the gas to be measured, the measurement accuracy is zero fluctuation of ±0.5%Rd±0.2g/h. In addition, a thermal mass flow meter μ-FLOW is provided for the measurement and control of small liquid flow, as shown in FIG. 4 . The smallest range of measurable flow is 1.5 to 30 mg/h. Measurement accuracy is ± 2% FS, reproducibility 0.2% FS.

2) Burkert

Baodi Fluid Control Systems (Shanghai) Co., Ltd. exhibited an oval gear flowmeter for the measurement of small, viscous liquids with a flow rate ranging from 0.008 to 8.33 l/min and a measurement accuracy of ±0.5% of the reading error. In addition, a thermal mass flowmeter for gas flow measurement is provided. The flow rate with the smallest flow rate can be measured from 0.005 to 10lN/min (N2), and the measurement accuracy is ±1.5%±0.3%FS of the reading. It uses a capillary sensor structure that can measure corrosive gases and toxic gases.

3) Digmesa, Switzerland

A series of flowmeters for small flow measurement of liquids such as water, beverages, wine, coffee, and chemicals are exhibited, as shown in Figure 5. They are based on the turbine and elliptical gear principle. The minimum measurable flow range is 0.03 to 0.60 l/min. The measurement accuracy is ±2.0% of the reading and the repeatability is ±0.25%.

4) The British Titan Flowmeter has exhibited a series of liquid micro flow measurement flowmeters based on the turbine and elliptical gear principle. When the oval gear flowmeter measures 30 cSt oil, the minimum measurable flow rate corresponds to a measuring range of 0.01 to 1 l/min, and the measuring accuracy is ±0.75% FS. For measuring water, the minimum measurable flow rate corresponds to a measuring range of 0.1 to 1 l/ Min, measurement accuracy is ±1.0% FS; repeatability is ±0.1%. The minimum measurable flow rate of the turbine flow meter corresponds to a measuring range of 0.03 to 0.35 l/min, a measuring accuracy of ±0.75% FS, and a repeatability of ±0.1%.

On display, a tangential turbine flow sensor produced by the Russian Industrial Instrument Group, with a minimum measurable flow range of 0.18 to 0.6 l/min. The measurement accuracy is ±0.5% of the reading and the repeatability is ±0.05%. The maximum working pressure is 40 MPa.

(3) Vortex Flowmeter At this exhibition, 21 manufacturers exhibited vortex flowmeters, accounting for 39% of the total number of exhibitors. Among them, there are 2 foreign manufacturers, accounting for 11% of the foreign manufacturers; 19 domestic manufacturers, accounting for 53% of the domestic exhibitors.

Because the output signal of the vortex flowmeter is related to the flow velocity, both the liquid measurement and the gas measurement can be performed. Especially in the energy monitoring, the measurement of the steam flow has been approved and accepted by users. In recent years, due to the application of digital signal processing technology, its measurement accuracy and range ratio have been significantly improved.

However, for the vortex flowmeter, because its working principle is to detect the vibration frequency of the fluid vortex, how to distinguish the vibration from the pipeline has always been a problem, so the ordinary products have poor anti-vibration performance. In this exhibition, several manufacturers exhibited anti-vibration vortex street, and some of them also elaborated the measured display model of the vibrating pipeline and achieved good results.

Jiangsu Weihao Electronics Co., Ltd. exhibited an anti-vibration vortex flowmeter. For gas flow detection, it is free from 2g@5~110Hz pipeline mechanical vibration interference; the span ratio exceeds 60:1; based on good repeatability accuracy, built-in 15-segment linear correction to achieve 0.5-level accuracy. The use of pure titanium sensor without plastic package.

Hangzhou Shutong High-end Instrument Co., Ltd. also exhibited a smart anti-vibration vortex flowmeter. The principle of self-damping differential measurement was used to minimize the effects of pipeline vibration and pulsating flow. Under 2g vibration conditions, It can still measure accurately and reliably. Spectral signal processing (SSP) technology was used. At laboratory conditions, the range ratio is 30:1, and for gas and steam flow measurements, the accuracy is ±1.0% of the reading.

(4) Ultrasonic Flowmeter At this exhibition, a total of 13 companies exhibited ultrasonic flowmeters, accounting for 24% of the total number of exhibitors. Among them, 6 are foreign manufacturers, accounting for 33% of foreign manufacturers; 7 domestic manufacturers, accounting for 19% of domestic exhibitors.

The United States General Electric (GE) exhibited the CTF878 clamped gas ultrasonic flowmeter, as shown in Figure 6. It uses cross-correlation TAG technology. Tests on 152 to 762mm (metal and plastic) pipes show that the accuracy is better than 1.1 to 46m/s in the flow rate range of the first 20D and the last 10D straight pipe. ±2% of the reading, repeatability is ±0.2% to ±0.6% of the reading, and the turndown ratio is 43:1. The minimum measured gas density is 1.2kg/m3. Wall thickness ≤Sch80.

GE also exhibited the Digital Torch Ultrasonic Flowmeter DigitalFlowTM GF868. Correspondence Transit-TimeTM is applied to the measurement of flare gas and exhaust gas, with a diameter of 50mm to 3m or more. When the first 20D and the latter 10D straight pipe segments are satisfied, the flow rate accuracy is ±2% to ±5% of the reading in the range of ±0.3 to 85 m/s for single-channel measurement; the accuracy of the flow rate for the two-channel measurement is ±1.4% to ±3.5%. Mass flow accuracy (hydrocarbon-air mixture), mono: 3% to 7%; binaural: 2.4% to 5%; calibration accuracy of ±0.5% of reading. In the range of 15cm/s to 30m/s, the repeatability is ±1%.

Tangshan Huizhong exhibited the SCL-61D series ultrasonic water meter. It adopts a bore body design with no pressure loss; the minimum flow rate that can be monitored is 2mm/s; the multi-channel design meets the national water meter accuracy; the power consumption is less than 0.8mW, and a battery-powered continuous operation for more than 6 years; The whole protection class IP68.

Tangshan Huizhong also exhibited CRL series ultrasonic heat/cooling meters. According to different uses, it is divided into three sub-series: household type, building type, and industrial type. Its industrial type is divided into separate and integrated types according to the structure, and two kinds of power supply modes, battery and AC, can be selected.

Ultrasonic flowmeter can measure various fluids in principle, but due to the low density of gas, it is difficult to measure. In particular, external clamped gas ultrasonic flowmeters are more difficult to implement due to the severe attenuation of the acoustic signal at the interface between the tube wall and the gas medium. The external clip-type gas ultrasonic flowmeter introduced by GE has broken through this difficulty and achieved external clamp measurement. In addition, a variety of gas ultrasonic flowmeters demonstrated by the company fully demonstrated the advantages of wide range, high measurement accuracy and wide application range of ultrasonic flowmeters. Ultrasonic flow meters are the fastest-growing flow meters in recent years.

(5) Coriolis Mass Flow Meter At this exhibition, a total of nine manufacturers exhibited Coriolis mass flow meters, which accounted for 17% of the total number of exhibitors. Among them, 4 are foreign manufacturers, accounting for 22% of foreign manufacturers; 5 domestic manufacturers, accounting for 14% of domestic exhibitors.

Siemens (SIEMENS) exhibited the Coriolis mass flow sensor Sitrans FCS200, which was specially introduced for the CNG market, and participated in this exhibition. This flow meter is small in size and has strong circulation ability. The maximum flow rate is up to 500kg/min (DN25mm). It can be installed in dispensers, filling columns and natural gas compressors for trade settlement, saving space and improving efficiency. It can be used for Fill quickly. Sitrans FC070 flow transmitter with built-in safety barrier, standard RS485 and pulse output, Siemens CNG solution is simple to operate, suitable for various CNG flow measurement settlement applications. The measurement accuracy is ±0.5% of the reading.

Coriolis force mass flow meters use the Coriolis force effect for mass flow measurement. Because the gas density is small, the Coriolis force generated in the measuring tube is weak, making it particularly difficult to measure. In recent years, Siemens and other companies have introduced Coriolis flowmeters that can be used for gas mass flow measurement, providing a very effective technical means for the measurement of high-precision gas mass flow.

(6) Multi-parameter smart compensated flowmeter For most flowmeters, only the volumetric flow under working conditions can be measured, and users often want mass flow or volumetric flow under standard conditions, especially when the gas is compressible. This need is even more urgent. The common practice is to install flowmeters, temperature and pressure transmitters at the same time. The secondary information processing unit such as a computer or integrator performs temperature and pressure compensation calculations to obtain the required flow values. Several years ago, a multi-parameter metered flow meter was introduced. Many companies exhibited a multi-parameter smart compensation vortex flowmeter at this exhibition.

Shanghai Jianyi Industrial Co., Ltd. exhibited a multi-parameter vortex flowmeter manufactured by Vortek Instruments Inc. in the US, as shown in Figure 8. It has temperature and pressure compensation and measures the mass flow of gas, liquid and steam. A flow meter can detect five process parameters of mass flow, volume flow, temperature, pressure, and density. In addition to the cumulative flow pulse output, it can provide three 4 ~ 20mA signals and three alarm outputs with HART or Modbus communication.

Siemens also exhibited a vortex flowmeter with built-in temperature and pressure sensors for intelligent temperature and pressure compensation.

(7) Use in Harsh Environment Many flow meter manufacturers have exhibited products that can meet the requirements of poor working conditions such as water immersion and burial. The protection class is IP68. Such as KROHNE's battery-powered electromagnetic water meter can meet the requirements of the entire table soaking and buried installation. The battery-powered ultrasonic water meter in Tangshan Huishang can also meet the requirements for flooding the entire surface.

(8) Other German fluid systems Co., Ltd. exhibited a Weser displacement gear flowmeter. It adopts the design of the circumferential gear, the force is more even and the pulsation is small; the resolution is improved by the double-wave multiplication, and the fluid flow can be discriminated. The range ratio is up to 1500:1, the measurement accuracy is ±0.3% of the reading, and the working pressure can reach 70MPa.

Conclusion

As for the flow meters displayed at this exhibition, there is still a large gap between the technical level and product quality of domestic and foreign manufacturers.

With the exception of a few large multinational corporations, most of the foreign manufacturers' products are less sophisticated and less specialized. Most of them have developed a single or two flowmeters to a higher level of technology through decades of technological accumulation, and have developed a variety of models to meet the different needs of users, and are striving to refine and refine products. Guarantee higher quality and build brand effect.

Compared with foreign countries, most of the domestic companies are busy increasing their product range in order to have a competitive advantage in the sales and engineering project bidding process. Most domestic flow meter manufacturers have the same level of technology and innovation. Therefore, there has been more repetitive and low-level development. In order to occupy more market share, similar instrument manufacturers adopt low-price competition marketing strategies. As a result, product quality is difficult to increase and the market is also confusing.

Coriolis mass flow meters, gas ultrasonic flow meters and other new high-performance, high-tech flow meters, the overall level of Chinese enterprises compared with similar foreign products, there is still a wide gap, especially in stability and reliability. The processing technology has weak guarantee strength, a small number of production companies, limited production capacity, and a small market share.

In recent years, new types of throttling flowmeters, such as V-cone flowmeters and multi-hole orifice flowmeters, have been improved in their measurement accuracy, range, pressure loss, and installation and use conditions, as compared with traditional throttling flowmeters. As a result, users who are welcomed by users and manufacturing companies are pouring in. Some companies have already begun research work, but generally speaking, research work remains to be done. In particular, a considerable number of companies use them as standard throttling flowmeters to manufacture them without actual flow calibration. Actually, there are large errors.

In a thriving and fast-growing country, a society where every company wants to develop rapidly, how to cope with and promote the transition and development of flow meter manufacturing countries to flow meter manufacturing powerhouses is a work that requires everyone to think together and work hard. Not only technological innovation, but also what is more needed is the innovation and progress of ideas, systems, unity, alliance, exchange, and competition to promote the healthy and rapid development of China's flow measurement business.