A high-efficiency ammonia (R717) refrigeration system from German manufacturer Bitzer will reduce cooling costs by an estimated 57% versus the legacy ammonia system at a Pilgrim’s meat processing facility in Bromborough, U.K.
The annual energy cost for the 707kW (201TR) ammonia compressor pack (ACP), which was commissioned by U.K.-based contractor Demeva Refrigeration in January 2023, is estimated at £61,000 per year ($77,510/€71,272). This represents a savings of more than £80,000 (US$101,664/ €93,460) annually (57%) compared to the site’s previous ammonia system, which was built by another manufacturer and had been in use for 20 years, according to a statement from Bitzer.
Based on these energy savings, Pilgrim’s UK said it achieved its goal of making a return on its investment within 1.5 years. In addition to reduced energy costs, Pilgrim’s UK also saved money by retaining the ammonia charge from its previous system (around 3,000kg/6,600lbs) for use in the new system.
The new Bitzer ACP system, which is powered by two high-performance screw compressors, provides primary cooling at an evaporating temperature of −9°C (15.8°F) for a secondary glycol circuit, serving the facility’s cold rooms at 2°C (35.6°F) and air-handling units at 8°C (46.4°F).
According to the manufacturer, during partial-load conditions, the system operates using just one of the ACP’s compressors, which helps to reduce energy consumption. The second compressor provides support during periods of high demand and for redundancy. In addition, the site’s old system remains connected to the cooling circuit and offers backup for when the Bitzer system requires servicing.
“The Bitzer ACP pack, combined with the other efficiency measures implemented by Demeva Refrigeration, will significantly reduce power consumption at Bromborough and deliver significant savings in carbon emissions,” said Neil George, Engineering Manager at Pilgrim’s UK.
Minor modifications were made to pipework and electrical connections to allow the new ACP to be installed in place of the old system in the site’s machine room.
“The Bitzer ACP pack, combined with the other efficiency measures implemented by Demeva Refrigeration, will significantly reduce power consumption at Bromborough and deliver significant savings in carbon emissions.”Neil George, Pilgrim’s UK.
High efficiency for industry
According to Bitzer, its ACP range has been designed to ensure high-efficiency cooling for industrial applications. It is based on Bitzer’s compact screw compressors, which allow a smaller footprint than equivalent-capacity reciprocating compressors.
“In addition to the inherent efficiency of screw compressors, the speed of the lead compressor is controlled by an integrated variable-speed drive, which significantly increases part-load efficiency and enables soft-start, important on sites where power headroom is limited,” Bitzer explained.
The screw compressors used in the company’s ACPs have much longer maintenance intervals than reciprocating compressors, reducing the cost of ownership even further, the company said.
In addition to its part-load efficiency, the pack features a back-up compressor for use in the event of a system failure and features a plug-and-play design for rapid commissioning.
“The modular design means that contractors can quickly connect up ACP units on site with a few simple pipework and electrical connections,” said Kevin Glass, Managing Director of Bitzer UK. “This dramatically speeds up the process of installation and commissioning.”
Prior to the ACP system’s installation, project leads from Demeva and Pilgrim’s UK visited Bitzer’s manufacturing and R&D facility in Stuttgart, Germany, to see the production process firsthand.
“Having assessed the technology currently available on the market, we believe Bitzer’s ACP system is the most efficient ammonia refrigeration solution available,” said Dean Rawling, Director of Demeva.
“Ammonia refrigeration systems have traditionally been built as one-offs, often in less-than-ideal conditions,” explained Glass. “Bitzer is able to build ACP units in a high-quality factory environment, ensuring the highest possible system integrity, absolutely essential when working with ammonia.”
Once the pack was installed by Demeva, Bitzer engineers traveled from Germany to the site in Bromborough, located just south of Liverpool, to assist with commissioning and ensure the system was optimized to deliver the anticipated savings.
The project is part of the meat producer’s wider, multimillion-pound efforts to improve the sustainability of its operations, with the aim of achieving net-zero emissions by 2030.