The complete refrigeration and chilling system of the Hamburg market trading company, “Die Neuenkirchener Heidekartoffel GmbH”, is economical, robust and durable. Efficient PlusChilling on the new stand in the main hall of Hamburg's Grossmarkt ensures that potatoes, onions, convenience foods and eggs remain fresh with consistently excellent quality. Compared to the old refrigeration installation, which in parts dates back to the 80's, around one third of the energy is saved with today's system.
The market trading company, “Die Neuenkirchener Heidekartoffel”, uses semi-hermetic GEA compressors for cooling and refrigeration processes
When everywhere else the lights have already long gone out in the truest sense of the word, it is brightly lit in Hamburg's main market, the Grossmarkt. Night becomes day in the three-section hall with the strikingly curved roof, which was built in 1962 and is protected as a historical building. Before midnight the traders start to lay out their range of products, ensuring that customers large and small can buy their fresh fruit and vegetables there. Trading with fruit and vegetables takes place here at night between 1 am and 9 am in the morning.
Business with fresh produce in the market is subject to tough competition - the structural changes in German food retailing have left behind clear signs in Hamburg. Whereas the customer base was previously made up predominantly of weekly market buyers, today it is primarily catering wholesalers, who order peeled and cut products.
One third energy saving
Business in Hamburg's Grossmarket is still even today agreed with the shake of a hand. This was also the case for the installation of the new refrigeration and chilling system on the new sales stand of “Die Neuenkirchener Heidekartoffel”. The refrigeration infrastructure of the original stand could not be transferred to the new location for reasons of economy and efficiency.
Part of the machinery had been in use for around 30 years, and overall it had decreased in output capacity due to the high number of operating hours. Seven compressors previously supplied refrigeration for eight cold storage cells. The insulation of the cold storage cells also did not meet today's requirements.
Today's concept by Wassim Dahche, project engineer at Westermann Kältetechnik GmbH in Hamburg, achieves an energy saving of around one third - measured against the energy consumption of the previous system - with a compound plant build by Westermann, based on the same cold storage volume and the same area.
The Westermann compound refrigerating plant with two suction gas-cooled semi-hermetic GEA compressors, together with direct evaporators, has a maximum refrigerating capacity of 60.0 kW. The system is output- and frequency-controlled, since the compressors are controlled via a frequency converter, while the SGBE 092C direct evaporator is regulated via electronically controlled injection valves.
The condenser has been designed for a high ambient temperature (34 °C), in order to keep the compression ratio low. This reduces the drive power and ensures that operation is very efficient.