Flow meters have an important position in the national economy

Flow meter is a tool to measure the change of quality, an important means to improve product quality, improve economic efficiency and management level. As there are many influencing factors, the principle of the instrument is as many as 10 kinds and the type is not less than 200. In the industrial automation system, it is the source of the signal, although the number only accounts for 1/5 of the system automation instrument, but the price accounts for about 1/3; in the scientific evaluation of energy saving, pollution emissions accounted for more than half of the monitoring instrument. Therefore, it has an important position in the national economy.

I. Market assessment 1. According to the online survey of Flowresearch in the foreign market, the average annual growth rate (CAGR) of the world market of flow meters has reached 2.6%, and the sales amount from 2002 US$3.1 billion increased to US$3.5 billion in 2007, with traditional instruments (throttle, volume, turbines, rotor flow meters, etc.) showing negative growth, CAGR of -2.2%, from US$1.643 billion in 2002 (53% of the total ) It dropped to US$1.505 billion (43%) in 2007, while the annual growth rate of new meters (electromagnetic, ultrasonic, Coriolis, etc.) averaged 6.2%, from 1.457 billion U.S. dollars in 2002 to 20.19 in 2007. Billion US dollars, of which the annual growth rate and sales volume of electromagnetic, ultrasonic and Coriolis flowmeters are shown in Table 1. The electromagnetic flowmeter's CAGR is less than 2% due to its large base and mature technology.

The survey believes that turbine flowmeters are commonly used in many countries in the world to measure gases or liquids with low viscosity. Due to the rotating parts in the meters, the maintenance workload is large. The CAGR for the past 5 years is -3.2%, and the sales amount is from 2002. The 410 million U.S. dollars fell to 348 million U.S. dollars in 2007. Experts believe that although ultrasound has been growing aggressively in recent years, turbines are much cheaper than ultrasound and have price advantages. Compared with throttling devices, the range ratio can be as high as 10:1, and it is more accurate. In trade settlement, it is still small and medium-sized. Customers are happy to choose. Volumetric flowmeters are non-velocity instruments. Installation requires no straight pipe sections. Accuracy can generally reach 0.5%, but it is cumbersome. The caliber is generally less than 0.2m. In the past five years, sales fell from 520 million U.S. dollars in 2002 to 452 million U.S. dollars in 2007, and the CAGR was -2.7%. Experts believe that new instruments replace conventional instruments in many fields and are an overall development trend, but the process will be long.

2. Domestic market According to statistics, in the domestic automation instrument market in 2005, the annual sales flow meter expressed 2.3 billion yuan; the pressure transmitter is about 1.8 billion yuan (of which about 500 million yuan is the differential pressure transmitter and difference. Pressure meter matching); temperature instrument 1.2 billion; level, level instrument 1 billion. From the point of view of the type of flow meter, because the throttling device is relatively heavy and the technical content is relatively low, foreign manufacturers have not basically involved in the Chinese market for this type of product. The selection of such instruments in China's projects is mainly based on domestic products, and the annual sales volume. Not less than 200,000 units, about 600 million yuan or more.

China's efforts to develop and develop flow meters have a large gap with foreign countries and are more satisfied with imitation. This issue can be seen from the well-known instrumentation show MICONEX2006. A total of 297 flow meters with more than 10 principles were exhibited by Chinese and foreign manufacturers participating in the exhibition. The frequency of the exhibition was listed in Table 2. As can be seen from Table 2, out of the 16 items classified, 204 manufacturers exhibited the first 6 items totaling 69% of the total, indicating that they are hot spots for Chinese and foreign instrument manufacturers, and Coriolis flowmeters are exhibited abroad. There are 17 companies accounting for 68% of the total, and only 8 in the country. Does it mean that the domestic measurement of the meter for accurate measurement of mass flow is insufficient in China; while the internal cone flowmeter, the number of domestic exhibitors reaches 30, accounting for 91% of the total; there are only 3 foreign countries. Is the domestic market overheated?

Electromagnetic flowmeters are still hot spots in flow meters and are in the first place. China's major instrument manufacturers (Shanghai Guanghua, Weltech, Kaifeng Instrument, Chongqing Chuanyi) are listed as the main products. According to the assessment of the US ARC Consulting Company, due to the special emphasis on environmental protection in recent years, China has been relying on the rapid development of Sheung Shui/Sewer, metallurgy, mining, pulp, and pharmaceutical industries. In the next five years, the electromagnetic flowmeter will reach 10.7% in China's CAGR. In 2003, the increase from 380 million yuan to 640 million yuan in 2008.

Ultrasound has many advantages, such as accuracy, pressure loss and small volume. It is particularly suitable for the trade measurement of precious fluids. Both at home and abroad have paid more attention to it. Only domestic exhibits are mostly used to measure liquids. Although there are several gas sensors, they are used on the spot, especially There are still some problems with trade settlement.

Thermoelectric exhibits are also many, because it can measure the mass flow, and the sensitivity is high, the industry's attention, but its plug-in form can only measure dry, pure gas, the accuracy is not as high as advertised by the manufacturers , It's still a long way from utility.

Second, the development trend 1, the structure is increasingly concise, portable early flow meter for pure mechanical local display, such as volumetric flow meter. Not only is the structure complex and bulky, the weight/aperture ratio is large; and the rotating parts therein require frequent maintenance due to wear. With the increasing diameter of industrial pipelines, plug-in meters are becoming more and more popular with users due to their simple structure, light weight and easy assembly and disassembly. The electromagnetic and ultrasonic flow meters with the fastest development in the past decade have no rotating parts in the pipeline. , Resistance parts, the structure is more concise, and the pressure loss is small, high accuracy, is the most potential flow meter.

2, the function seeks to improve, and various early flow meters for the local display (such as volume, rotor), with the continuous improvement of industrial standards, can not meet the process requirements of dozens of instruments centralized display, regulation, control. It is necessary to separate the sensor (also known as a table, orifice, nozzle, cone) from the transmitter (also known as the secondary meter). The flow parameters are converted into electrical parameters and transmitted to the central control room. With the expansion of industrial scale, analog signals can no longer be adapted, and the output signals need to be converted into digital signals to meet the requirements of field bus systems and SCADA systems.

In order to increase the reliability of the instrument, many instruments have added more than 10 kinds of self-diagnosis functions. For example, Optiflux electromagnetic flowmeters from KROHNE can self-diagnose many aspects of the instrument such as air bubbles, electrode corrosion, fouling, electrode short-circuit, fluid conductivity, non-full tubes, lining damage, and external magnetic fields.

The diversification of instrument functions is also a trend of development. For example, in addition to measuring the flow of ultrasound, fluid composition and sound velocity can be measured. In addition to measuring flow, Coriolis can measure the fluid density.