draft beer, ice bank, experimental analysis
In a long-term established application as draft beer cooling and servicing machines, seems difficult to see any research application at first sight. However, this perspective change when one considers that the costs associated to maintenance/operating problems are very high for breweries with a very extensive network of machines. Moreover, the strong competitive market among different companies means that any cooling failure could be an opportunity for the competence. An additional aspect to consider, is that the climate and installation variability among different machines asks for a complete a-priori understanding of the unit behavior under integrated operating conditions, in order to select for each location and ambient the optimum machine (lowest cost for the brewery while keeping the cooling needs for the customer). All these statements justify a complete research analysis, based on experimental testing of the machines under different situations, in terms of beer storage temperature, room temperature, consumption profile, and integration effects (ventilation, connecting ducting lengths, etc.). Under this framework, this paper presents in detail an experimental set-up developed ex-professo for this application, showing how the different aspects have been instrumented in order to provide the needed performance parameters. Special attention has been taken to monitor the ice bank status along a particular operating and consumption scenario. To close the paper, illustrative results will be given for some representative cases, showing temperature evolution for the ambient, the inlet/outlet beer, the refrigerating system, machine consumption, ice presence at different locations, etc. From the data obtained were determined the effect of some operating conditions on the machine performance and gathered for comparison purposes. From the presented information, the level of understanding achievable with the obtained data will be clearly demonstrated, and thus the corresponding economic benefits for the breweries covering a similar research work.