The influence of the thickness of the heat-insulating layer and the bulk of the cold source on the time of its storage

The preservation of snow or ice to be used in air conditioning systems in countries with cold and snowy winters enables one to significantly save energy in summer. The main problem to be solved when using natural cold sources in cooling systems is to maintain the required amount of cold before the start of the operating period and in its course. The paper presents the ways of the maintenance of renewable cold sources and the design of a cold generator. It contains the authors’ method to define the storage time for cold source depending on the amount of the cold and the heat-insulation layer of the cold generator. Determined are the operating mode of the cold store and the ways to preserve snow or ice. On the basis of the patent obtained by the authors, a pilot unit of a three-stage cold generator has been designed. Presented are the results of experimental studies on the storage of natural source of cold in the cold generator, the model of the distribution of cold losses, and the results of the calculation of the heat balance in the “three-step cold generator” unit. Determines are the degree of the effect which the bulk of the cold source has on the time of its storage as well as the dependence of the time of storage on the thickness of the heat-insulation layer. Basing on the research it is possible to determine the optimal thickness of the insulation and the storage time taking into account the amount of the cold source of and the period of operation.