Managing Multiple Compressors for Reliability and Energy Efficiency
Managing multiple compressors for energy efficiency is a hot topic. It has been approached in many ways and it is the primary and sometimes sole offering for some companies. Unfortunately a “one size fits all” approach doesn’t apply here. It is extremely important to manage different types of compressors differently. This couldn’t be truer than when you’re talking about centrifugal compressors.
Unless you are the exception to the rule, your demand profile does not perfectly match your supply side capacity and you have a need for load sharing. Whether you call it Load Sharing, Load Shedding, or Load Balancing one fact remains. “You cannot accomplish true load sharing without having an open local controller that is designed to dovetail with the master controller” The OEM local controller is designed to control and protect one compressor without regard for what the rest of the system is doing.
When AirLogix is applied as the local controller, you will have an open foundation for automation of the group of centrifugals. This is where AirMaster comes to work.
AirMaster™ Load Sharing Solution for Centrifugal Compressors
AirMaster is a pre-engineered, highly configurable, PLC system that sequentially throttles compressors ensuring that all of the turndown for the first has been used before throttling the next. The goal is to eliminate unnecessary blow-off by utilizing the turn-down of all centrifugal machines in the system until maximum system turndown has been reached. In other words, you will see multiple machines throttle to keep from opening blow-off valves, until there is sufficient capacity to allow one machine to unload and timeout. Under the rules defined by you, an unloaded machine can be shut down and restarted automatically to further maximize energy savings.
AirMaster™ for Non-Centrifugals
When Rotary Screws, Variable Speed Screws, or Reciprocating compressors are in the mix with or without centrifugals an engineered approach is taken to gain the best energy efficiency possible.
AirGate™ Multiple Header Management
When air is compressed and distributed at two different pressures, there are often efficiencies to gain by bleeding excess capacity from the higher pressure header to the lower pressure header. But this should be done in conjunction with proper management of both the high and low pressure compressor systems to be sure that the crossover doesn’t force lower pressure machines to blow off, or higher pressure machines to start unnecessarily due to the additional demand. For this application we offer AirGate, a PLC controller to coordinate the crossover valve(s) with the control systems on either side.