Evaluating the effects of weather conditions on the useful heat gain of the solar water heating system

Abstract

The aim of this research is to evaluate the effects of weather conditions on the useful heat gain of the solar water heating system. This system has been designed, fabricated and installed in the Ho Chi Minh City University of Technology and Education. It consists of four flat plate collectors parallely connected with the total collection surface area of 8 m². The volume of storage tank is 300 liters and the water flow rate through collector loop is 0,132 kg/s. In this study, the experiments were carried out on three types different of days, including clear day, intermittent cloudyday and overcast sky day, to evaluate the effects of weather conditions on the useful heat gain of the solar water heating system. The average values of the global solar irradiance incident on the collector surface of the three above different days are 602 W/m², 412 W/m², 284,5 W/m², respectively. The experimental results show that the useful heat gain of solar collectors for domestic hot water production of the clear day, intermittent cloud sky day and overcast sky day are 10,22 kWh, 4,4 kWh, 0 kWh, respectively, and the corresponding energy consumption of collector loop pump is 2,1 kWh, 1,28 kWh, 0 kWh, respectively.