Compatible ‘Made in China’ DCSs enhance quality, productivity
Because they can help improve process control, consistency, and productivity, distributed control systems (DCSs) are gaining increasing attention among China's plant directors. In fact, some large Chinese process industry plants began using DCSs about 10 years ago to help make products meeting the same standards as those from other countries.
Because they can help improve process control, consistency, and productivity, distributed control systems (DCSs) are gaining increasing attention among China’s plant directors. In fact, some large Chinese process industry plants began using DCSs about 10 years ago to help make products meeting the same standards as those from other countries.
However, nearly all these DCSs were products from companies such as Foxboro, Honeywell, Yokogawa, etc., imported mostly from the U.S. and Japan in the 1980s. They operated on many different types of computers, and played a significant role in China’s plants for many years, but these imported DCSs have since become obsolete and no longer to meet production needs. Leaders of some of China’s ministries (machine-building industry, chemical industry, and power industry) realized it would be very difficult to increase productivity on a large scale in China if they depended only on imported control and instrumentation to run processes.
The only solution was to develop a Chinese DCS and use it to renovate production processes in China’s plants. “Made in China” DCSs were developed and began operating in some large plants a few years ago, following investigation and development by Chinese technicians aided by international technical experts.
Though system networking is a key element of DCSs, compatibility of traditional DCSs in China wasn’t good because they were designed specially by each supplier. To overcome this problem, “Made-in-China” DCSs incorporated generalized system networking in their configuration. In the past, generalized system networking, based on IEEE 802.X, had been used in the foreign DCSs. Besides its excellent compatibility, generalized system networking also works in real-time and is highly reliable, which improves DCS performance.
At present, several hundred “Made in China” DCSs are operating in some of China’s largest plants, mostly in the oil, chemical processing, and power generation fields. Some organizations, such as Beijing Ho-Li Automation Engineering Co., were formed to distribute these systems.
For example, a few Chinese DCSs have also been exported to countries, such as Pakistan, where they are operating successfully. Experience in these plants shows “Made in China” DCSs—which also combine distributed control with advanced instrumentation—provide process control and production management that improves quality and makes production more economical.
Still, many plants in China urgently need technical renovation, and so are increasingly seeking and using automation to improve their productivity. This is increasing demand for DCSs, but limited manufacturing capacity has meant that Chinese DCS suppliers have only been able to provide half the DCSs needed domestically. Consequently, as the desire for improved quality products pushes implementation of improved automation in China, new opportunities are still opening for foreign companies that can deliver state-of-the-art DCSs and manufacturing technology. China remains a great potential market for distributed control systems.
Zhang Sie Lin, senior engineer, Beijing Research Institute of Automation for Machinery-Building Industry, Beijing, China. For more information, contact the institute at: Fax +(010) 62025604; E-mail: email@example.com
‘Made in China’ DCSs at-a-glance
Characteristics of “Made in China” distributed control systems (DCSs) operating in Chinese plants include:
Nearly 70% have 1,000 data acquisition (DAC) points; 50-100 control loops; and 3-7 workstations;
Nearly 25% have 3,000 DAC points; 150-300 control loops; and 10-15 workstations.
A few “Made in China” DCSs, such as HS2000, which is now operating in power stations, even incorporate fieldbus technology in their architectures to expand functional distribution.
Source: Control Engineering with information from Zhang Sie Lin, senior engineer, Beijing Research Institute of Automation for the Machinery-Building Industry.