Application of direct contact cold accumulators in air conditioning systems

Introduction. The study puts forward a proposal to use cold accumulators for air treatment in air conditioning systems (ACS) of buildings and structures in order to reduce the load on the refrigeration machine during peak operating conditions, as well as to equalize the load on equipment. A number of sources were analyzed, confirming the relevance of the study and covering the topic under study in detail.

Materials and methods. Two schemes of a cold accumulator based on direct contact of media are proposed, and mathematical models of the crystallization and accumulation process are constructed. The operating parameters of the refrigeration machine as part of the ACS are calculated and the energy consumption of the ACS is optimized using the Lagrange multiplier method.

Results. Liquid media, primarily salt solutions and freons, were mainly considered for cold accumulation. Analysis of sources showed that cold accumulators with direct contact of media are an effective and promising technology for increasing the energy efficiency of refrigeration systems of buildings and structures. Based on this, a detailed calculation of the accumulator was carried out. A mathematical model of the solution crystallization process during ice accumulation was built and the parameters of the accumulator and refrigeration machine were calculated. Two schemes of cold accumulation technology in the refrigeration machine system of the ACS were studied — by the method of separate ice production and an ejector scheme. The obtained modeling results showed that the use of new cold accumulation technologies in ACS systems allows re-
ducing energy costs for operation by 20–30 % and reducing initial capital investments. The economic effect is achieved by reducing the load on the equipment at peak consumption values. This allows us to say that for the design stage it is possible to reduce the equipment power by selecting it based on half-peak values, with compensation using accumulation.

Conclusions. The data obtained showed that the proposed cold storage solutions have lower energy consumption compared to analogues by 20–30 %, and are also capable of increasing the efficiency of ACS.

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