Beefy’s Pies Factory

Beefy’s Pies have been a long term customer we have worked with them to many extents, from servicing, repairs and maintenance to capitol works & new installations.

We utilised our partnership with Energy Flex to provide a day one evaluation, but also ascertain how and where they were using their energy, giving us a great starting point to look into the right areas of what’s being used and where costs savings could be achieved.

The use of Instantaneous Hot Water Units was an obvious major contributor to high energy use, but also increased baseline peak demand. On the other hand, we highlighted a huge waste of energy in the form of Air Cooled condenser heat rejection, a common form of cooling the refrigeration system and process.

Stage One – Repurpose & Recover

We engaged and worked with several engineers in different fields to come up with the concept of a heat recovery system. The concept is by no means new or unheard of, but rather relatively unexploited in this proportionally small scale. The design was simple, reclaim the wasted heat from the refrigeration systems and utilise it to pre-heat the required hot water used in the factory. There were several design factors, requirements and constraints that were overcome, but ultimately we achieved success beyond our expectations.

• 2x three phase Instantaneous H/W units were removed completely.
• 3 additional H/W storage units were made redundant.
• In-coming Hot Water was pre-heated to 40-50 degrees, utilising the heat exchange system.
• A new 3.6kw single phase element H/W storage unit was utilised to boost the water to desired outlet temperatures.
• Refrigeration system efficiency was improved with more consistent head pressures.
• Air cooled condenser fan usage was dramatically reduced.
• Site water usage was dramatically reduced.
• Labour time for wash room tasks was reduced significantly.

Overall

18% site energy reduction

40% reduction in Peak demand charges

30% reduction in water usage

Stage Two – Adapt and Retro-fit

Multiple Variable Speed Drives (VSD) were retro-fit onto the existing Direct Online (DOL) refrigeration compressors. The VSD has proven results of reducing the energy input of each compressor by 20-25% as well as eliminating the normal DOL peak starting current and hence the cumulative site peak demand. General wear and tear on the equipment is also dramatically reduced and resulting longevity of components means less breakdowns, repairs and replacements.

Stage Three – Revise and Improve

Another common practice of low temperature refrigeration systems is to use electric element heaters for defrosting of refrigeration freezer room evaporator coil units. Not only are these heaters high wattage and high current drawers’, they also operate at very high temperatures of +100degs. This intense heat causes vaporization of the ice formed on the evaporator coil, resulting in steam and humidity being kept inside the freezer room & increasing room temperatures, hence adding to refrigeration load once normal operating cycle recommences.

Once again, we engaged the engineers at Beijer Ref & Insinct to custom design a dual circuit embedded glycol evaporator coil unit. The normal electric heaters were replaced with a separate circuit of copper pipework, plumbed into a glycol reticulation system that was heated using the same heat reclamation system installed in Stage One. Not only did we eliminate the electric heaters completely, but we created a more effective and efficient defrosting cycle utilising the waste heat energy from the very refrigeration systems creating the alternate cooling cycle.

Defrost cycles are quicker, and the room is dryer due to the fact that the ice is melted slowly but consistently from the embedded warmed glycol with 100% of the moisture being drained away. The refrigeration system is in turn more efficient and the post defrost recovery time quicker due to not having a large increase in ambient temperature and load around the evaporator unit. We could also reduce the quantity of defrosts as they were no longer required.