Maintenance Management and Control System Integration

A blog post by Emerson’s Anand Iyer.

Emerson's Anand IyerSince the days of my “initiation” in this field, machinery protection has always been another system, whose domain has been questioned many a times. While the instrumentation and control (I&C) team would probably maintain the probes and systems, the higher level could fall into “rotating equipment specialists” or mechanical engineering domains. Nevertheless, basic information has to be shown to the operators. And trips have to happen. So these systems have had I/O connection to control and shutdown systems.

Many cost-cutting measures have been typically adopted through ages and maybe rotating machinery has a speed probe, but this is just connected to a trip amplifier type device and you get a trip contact only.

And, I have seen the rotating equipment specialists try to open the covers (many a times they are dependent on others to get their work permits and others to open the covers and so on), find a suitable spot to get their portable measuring device in to get a reliable readings. How they wished that this had as many probes connected to machinery health management (MHM)‘s as other equipment’s…

The thing that strikes one most is that the DeltaV control system is within proximity of integrating the MMS capabilities into the conventional I&C domain. The CSI 6300 SIS in DeltaV SIS form with direct interaction with the DeltaV SIS electronic marshalling in some future DeltaV version would probably make an amazing solution. Several junctions in circuits and trip (false) possibilities would be eliminated.

control system-logic solver-machinery protectionThe figure shows a conceptual machinery protection CSLSMP (control system-logic solver-machinery protection) and I/O representing the interface to machinery input devices (eddy current via converter etc.)

While some may be even of the opinion to have machinery input IO electronic marshalling, characterization modules in the future.

In either way, the scheme would allow machinery information to be captured much better than just the trip information by conventional means, with a lot more reliability.

Machinery Health Monitoring CPU with IOAnd when we have the SIS information, would users then thirst for more maintenance management system (MMS) integration where in a CSI6500 CPU in DeltaV processor format could be sitting on the control network with I/O integrated to the CPU. CPUMP would probably be the Machinery Health Monitoring CPU with I/O (Machinery monitoring I/O with connection to different probes).

Critical SIS rated machinery protection components would probably shift to CSLSMP systems like configuration, while others considered not so critical may still be retained in this CPU.

An overall PCS, SIS, MMS integrated architecture would probably be opening up new avenues in process control not yet thought of.

DeltaV System with MMS Integration
While most of the components would retain their present specialization and flavor, some items that become additional when you have two different systems rather than one may get eliminated. Information sharing between the systems would be enhanced to levels not yet thought of. Suddenly all the sensors that are now only providing a digital trip contact would, when properly connected, provide access to their machinery health related information.

One is most excited about the new advanced control opportunities that such integration may throw up. For example, new advanced control strategies residing in the MMS Advanced Controller, would take into consideration, the machinery information data that would now be possible. For example, if a plant load is shared between two compressors, at present each sharing 50% and the individual efficiencies are at 51 and 49 then the load would be so distributed keeping in mind what is best for that equipment. Imagine having the turbines operating at the best point of the curve that is possible, at every load conditions…

Though many advanced information systems on machinery exist and advanced controls also exist, the very fact that these systems could be within different departments / domains within an organization, may inhibit maximum utilization. Data sharing and decisions may happen after several meetings, thereby having equipment operating at not so optimal states till everyone agrees. An integrated form would allow users, scholars, scientists and engineers of the future, to think of more uses then we are able to envisage now.

Looks like a winning combination as of now…

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