Environmental Project, 951 – Comparisons of Energy Consumption for Refrigeration in Supermarkets

6 Conclusion

Based on the above results it can be concluded that the cascade systems have the same energy consumption as a well-dimensioned conventional system.

Lower energy consumption in the cascade systems can be expected if the control of the circulation pumps is improved.

The energy consumption of the cascade systems can be further reduced by improving the algorithms controlling the electric power in connection with the defrosting of the flooded evaporators in the cooling section. During the period of measurement, the defrosting functioned in the same way as for dry evaporators. But when defrosting started, the flooded evaporators had a greater liquid content than the dry evaporators. Therefore, energy consumption can be reduced in two ways, firstly the direct electrical consumption by the defrosting heat elements can be reduced and secondly the indirect consumption by the compressors. The increased power consumption by the compressors is due to the fact that the liquid in the evaporators is evaporated by the heating elements and not as a result of advantageous cooling in the evaporator.