System Optimisation is the evaluation of systems to determine how well the equipment is matched to the system. This article aims to provide Baldor Australia Pty Ltd customers / end users an overview of System Optimisation.
For many industrial facilities, the energy consumed in pumping fluids comprises a large fraction of the overall facility electricity usage. Operators of pumping systems often are not aware of how effectively the energy required to pump the fluids is being used.
In large industrial facilities, it is common to find several hundred pumping systems. Are all of these systems equal in terms of overall production importance? Of course not, there are a few systems that are absolutely critical. If they are unable to meet their functional requirements, a large part of the plant - or perhaps the entire facility - will be affected. On the other hand, there are a few systems which, if lost, would be little more than an inconvenience.
Likewise, the amount of energy consumed varies considerably from system to system. A study done by the U.S. Department of Energy showed that less than 6% of the motor population had a rated capacity of greater than 50 hp (37.5 kW), but that small portion of the population accounted for over 70% of the electrical energy consumed to drive motors.
Principals of System Optimisation:
As a rule it is generally recommended that pumping systems that already employ adjustable speed drives or which use positive displacement pumps be set aside. This is not an absolute rule; for example, if there is a 500-hp positive displacement pump and the largest centrifugal pump is 50-hp, then clearly one would depart from the rule. But all else being equal, it is recommended that the focus be on fixed speed centrifugal units.
Just as certain health symptoms in people are often - but not always - associated with certain illnesses, there are a few symptoms in pumping systems that often exist when there are improper sizing, selection, operation, or other issues that result in less-thanoptimal performance. The symptoms are listed below.
- Systems in which valves are throttled to regulate flow rate, level, pressure, etc.
- Systems that employ bypass (re-circulation) flow regulation
- Systems which involve a batch type process, and in which one or more pumps operate continuously
- Frequent on/off cycling of a pump in a continuous process
- Presence of cavitation noise either at the pump or elsewhere in the system
- An equipment procurement policy that is based on lowest bid price
- A multiple parallel pump system in which the same number of pumps are always in operation
- A pumping system that has undergone a change in function (for example, the system formerly provided cooling water to eight plant heat exchangers, two of which are no longer in service), but with no change in pump equipment or operation
- A pumping system with no flow, pressure, or power indication (akin to driving a car with no speedometer, gas gauge, and other critical indicators).