ABB inverter drives offer big saving in retail refrigeration applications
ABB inverter drives offer saving <50% in retail refrigeration applications
It is estimated by ABB that refrigeration accounts for on average, 40 percent of a retailer’s energy bill, while compressors and condensers, account for 30 to 35 percent of total refrigeration costs. The rest is consumed by the display and storage cooler fans, display case lighting, and for anti-sweat heaters used to prevent condensation on doors and outside surfaces of display cases.
All retailers, including department stores, supermarkets and convenience outlets can potentially reduce their energy bill by an average of 50 percent by installing variable speed drives (VSDs). A drive is a device that can be used to regulate the speed or torque of an electric motor. These devices control pumps, fans and compressors, eliminating energy waste.
Compressors provide refrigerant gas to the buildings air conditioner systems and to the supermarket food cases 24/365. A compressor that runs at full speed and at full load is a very efficient device; one that runs at less than those values becomes more inefficient unless there is a VSD applied to it.
The VSD adjusts the speed of the compressor (reciprocating, screw, scroll) based upon the temperature control needed to preserve food or maintain the buildings comfort. Energy usage is reduced by maintaining the required set point. By adjusting the speed of the compressor, the compressor is no longer cycling on and off (short cycling) eliminating demand load. In addition to reducing energy use, the system runs smoother and mechanical fatigue and pipe stress is no longer an issue. Slugging is also eliminated.
– Eliminates on/off cycle
– Smooth running system, reducing mechanical issues
– Temperature better regulated
– Reduced energy consumption
The system involves heat transfer in which a substance is condensed from its gaseous to its liquid state, typically by cooling it. In so doing, the latent heat is given up by the substance, and will transfer to the condenser coolant.
Using a VSD within this set-up helps to reduce energy costs due to fan affinity laws, whilst also allowing users to repeatedly set point head pressure control helping to further reduce energy and abate ambient noise; due to the elimination of contactor “staging” on and off of the fans.
– Elimination of mechanical stress
– Reduced noise levels
– Improved process control
– Lower maintenance requirements
– Better energy consumption
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