Modeling of a helioabsorption heat pump system for hot water supply

Abstract

THE PURPOSE. A domestic hot water supply system is proposed, combining a solar collector and a heat pump for the climatic conditions of the city BAC NINH - VIETNAM, capable of providing hot water to 5 users all year round. Justify the performance of the proposed system under these conditions. METHODS. The solution of the problem was carried out experimentally and by the method of mathematical modeling. The mathematical model is based on the energy balance equations taking into account the efficiency factors. The scheme and principle of operation of the pilot plant and the results of the calculation of the combined hot water supply system based on the monthly average values of the total daily radiation for the location of the solar collector are presented. The system contains a solar collector with vacuum heat-absorbing tubes and an air heat pump as energy sources. With sufficient solar radiation, hot water is generated entirely from the heat-absorbing vacuum tubes, stored in the reservoir of the solar collector and passes through the reservoir of the heat pump to the consumer when the heat pump is not working. In case of insufficient solar radiation, the air heat pump is switched on.RESULTS. The calculation of the power of the solar collector based on the average monthly values of the total daily radiation and the efficiency of the solar collector, the amount of heat added to the solar hot water supply system, the heat capacity of the heat pump, and a heat pump for the hot water supply system was selected. CONCLUSION. The results of the experiments confirm the calculations for replenishing the heat deficit for the solar collector with an air heat pump of low power at any time of the year. The calculations are made for a system that provides hot water for the daily needs of five and three people. It is shown that the low heating capacity of the heat pump allows one to reduce the cost of initial investment in domestic hot water supply systems with a solar collector and, accordingly, the prospects of the proposed hot water supply system in Vietnam.

Keywords

• hot water supply system
• solar collector
• heat pump
• mathematical model