炼油厂使用工业无线进行远程监测

Sending information quickly across distances is still important. Traditionally, landlines and wired connectivity have provided the best communications solutions. If it is not possible to link systems by wires, communication has been very difficult, particularly for industrial applications.

Into this wired world came wireless technology, for example, the personal mobile phone. While clunky and unreliable at first, now it is the preferred telecommunication method for millions of people.

Similarly, concern about wireless security and reliability in industrial settings has limited deployment in the past. However, current technology now supports robust and reliable industrial Ethernet-based wireless systems. We are at a tipping point for the adoption of wireless, as shown in the following example of how one refinery is using it in areas where cable is not available or is too expensive to install.

An Industrial Wireless Solution for a Harsh Environment

At Tula Refinery, part of Petroleos Mexicanos (PEMEX), management wanted to create an automated remote monitoring system that would reduce wear and tear on equipment in its cooling towers and reduce monitoring expenses.

Oil refineries, however, like many other industrial facilities, present a difficult terrain for establishing wireless connectivity. Plant structures, including the cooling towers themselves, often obstruct acceptable line-of-site for effective signal transmission.

Harsh environmental conditions can also be a challenge. Temperature extremes and element intrusion from water and debris can quickly degrade commercial grade devices that are not rugged enough for them. In the case of the PEMEX refinery, gear needed extra protection to guard against damage from sparks and it had to be certified to do so from the American National Standards Institute (ANSI).

Using a series of calculations and design strategies, the installation team was able to create robust and reliable wireless connections despite the physical difficulties. Some key factors were:

• Mast heights had to avoid desulfurization areas and still guarantee the Fresnel Zone. (The Fresnel Zone is the area in which radio waves spread after they leave the antenna.)
  
  
• Repeater stations were used whenever line-of-site was compromised. Strategically located Hirschmann BAT54-F X2 Access Points provided the communication backbone for both point-to-point and point-to-multipoint wireless Ethernet connections.
  
  
• Rapid Spanning Tree Protocol (RSTP) redundancy ensured network availability.
  
  

Results: Improved Remote Monitoring and Productivity

Industrial Ethernet provided the platform for the new monitoring system.

Vibration measurement devices were connected to a mechanism that shuts off the critical tower cooling fan engines any time abnormal vibration is detected. The monitoring system continuously transmits information on the status of the fans and the water cells to an operations center from a wireless radio in a satellite electrical room. 

A continuous data feed has replaced hourly visual inspections. The refinery now has up-to-the-minute information that increases its ability to regulate cooling tower efficiency and avoid dangerous and costly fan shutdowns.

The wireless connection allows PEMEX to take action automatically and/or remotely in response to abnormal readings and alarms and to design effective preventive maintenance schedules. Both extend equipment life. In addition, the company has redirected plant personnel to more productive and cost effective activities.

The result is that protecting a $9 billion oil refinery is possible using today’s wireless technologies.  More information on this PEMEX wireless application is available in the link to a Control Engineering article below.

If you have not looked at wireless for your industrial applications, now is the time to revisit the state-of-the-nation with this technology – you might just find a solution for a challenging project.