French cheese factory reduces energy consumption by 70% with NH3 system

By Pierre Wattré, May 23, 2014, 15:43 2 minute reading

A cheese factory from “Compagnie des Fromages”, part of the Bongrain group, located in Vire, France, dramatically reduced energy costs and CO2 emissions by installing an NH3 screw compressor from Vilter, part of Emerson Climate Technologies Group. Cofely Axima, a company belonging to the GDF Suez Group, was commissioned to develop the innovative heating and cooling installation.

The ammonia system, which both heats and cools, features a Vilter single screw compressor and variable speed drive. Based on Cofely Axima’s study of the cheese maker’s heating and cooling needs, a thermo-refrigeration pump was determined to be a more suitable solution than four piston compressors only able to generate cold.

“The benefits are not only gained by changing the hot water production process, but are also due to the energy-efficient components used in the new system,” said Jean-Yves Druillennec, Sustainability Director at Cofely Axima GDF Suez.

Zero energy waste thanks to combined heating and cooling system

The thermo-refrigeration pump simultaneously provides cooling capacity on the evaporator side and thermal power on the condenser side. As a result, the cheese factory is able to refrigerate 1000kW of ice water, and in the same cycle recuperate 1300kW of energy to warm water to +62°C, with an additional electrical consumption of only 100 kW. All the energy produced by the system is recovered so there is no energy waste.

A 150 m3 energy storage unit means the system is adaptable to fluctuations in hot water demand, and the consumption increase during the cleaning process. Previously, the hot water was provided by a gas boiler, whilst the refrigeration system’s waste heat was not collected, but rejected using a cooling tower. The new installation therefore saves 9000m3 of water per year, and has reduced the use of the cooling tower.

The system has the following features:
  • 390kW motor
  • 1000kW Vilter screw compressor
  • Heats water from 15°C to 58°C
  • Cools water to 1-7°C

Efficient system reaches a COP of 7.76

During the heating process, when both hot and cold water are produced, the system reaches a combined COP of 7,67. The production of ice water only, achieves a COP of 5,75. The installation is able to collect 100% of the excess heat from the ice water making process.

Payback in 18 months

The payback period for this installation is 18 months according to the Compagnie des Fromages. Whilst previously, the separate production of ice water and hot water consumed on average 820kW per ton produced, with the new installation, the energy consumption has been reduced to 560kW.

“The return on investment is particularly short,” explained Patrick Marie, responsible for maintenance at the Compagnie des Fromages.


By Pierre Wattré

May 23, 2014, 15:43

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