Objective The main project objective is to reduce the energy consumption of a refrigerating plant for fast freezing and storage of food stocks (Frigoscandia storehouse, 114000 mc).Further objectives are the following :- to minimize manual operation;- to obtain accurate fault diagnostics and alarm report;- to record electric energy absorption data for each time period, which will serve to work out the energy account report and to optimize the electric energy supply contract;- to exploit cheaper electric energy night fares;- to provide historical data on factory operation for the project of future plant enlargements.During the tests and measurement phase the system had to be shut down twice for a few days, due to a chart breakdown in the automation system. However, a total plant black-out never occurred as the fault affected only the SLAVE unit.The fault was limited to this unit thanks to the self-diagnosis device which, as soon as it detects faulty operation, sends an alarm signal to the MASTER unit. Then all the outputs to the equipment are blocked in the state they were in before the fault.The project can be considered as technically acceptable, since all the basic requirements have been met as planned with the exception of the cold accumulation system because of incompatibility between the accumulation material and the plant refrigerating fluid (NH3).The energy savings were significant but lower than foreseen, namely 6% instead of the expected 18% (299 MWh instead 935 MWh).Nevertheless the system has contributed to reduce manual operation and improve fault diagnostics and alarm reports.Furthermore it provides data on electric energy absorption which will serve to work out the energy account report and the optimization of the electric energy supply contract.The refrigeration plant consists of 7 cold storage (- 25 deg. C) rooms of 114.000 m3 total capacity and 1 air blast tunnels capable of handling 25 T of product/d. Refrigeration equipment consists of 25 air convectors, 6 screw compressors,4 evaporative condensors and 4 electric pumps for liquid ammonia circulation. The computer control system is comprised of 1 sensor interface for data collection, 1 PC IBM-type elaboration unit, 2 master units, 10 slave units, 1 graphic color screen unit and 1 graphic printer. Data collection and processing by the control system allows optimum control of the plant by: - intermittent operation of air convection ventilators - stabilisation of energy demand by synchronisation of low temperature demand, of screw compressor start/stop operation, pump station control and, in order to maintain pressure as low as possible, optimisation of the evaporative condensors and cooling towers set point.In addition, a 20 m3 cold store supplied by fusion heat derived from an eutectic mixture, provides a total refrigeration capacity of 1.000 Kfrig at - 32 deg. C during the night tariff period, for use during day and peak periods.PHASESPHASE 1 : Definition of operating requirements and definition of specifications.PHASE 2 : Selection of suppliers and commission.PHASE 3 : Project execution.PHASE 4 : Pre tests, check-up and final tests.Phase 5 : Test and measurement, certification. Programme(s) ENG-ENALT 2C - Programme (EEC) of demonstration projects relating to the exploitation of alternative energy sources and to energy saving and the substitution of hydrocarbons, 1983-1985 Topic(s) 3.2 - INDUSTRY Call for proposal Data not available Funding Scheme DEM - Demonstration contracts Coordinator Frigoscandia SpA EU contribution No data Address Via Monzoro 140 cornaredo 20010 San Pietro all 'Olmo Italy See on map Total cost No data
