Assessment of the performance of solar water heater: an experimental and theoretical investigation

Abstract

This study aims to evaluate the performance of a flat plate solar water heater (SWH) theoretically and experimentally. The thermal performance of the SWH was predicted using Fortran 90 programming language. SWH was designed as a square shape with dimensions of 110 cm length, 120 cm width, and 10 cm depth, and tested by integrating with a modified solar distiller to increase the water temperature in the basin at a constant mass flow rate of 1.2 liter/min. The tests were conducted under the weather condition of Ekaterinburg city, Russia, from June to September of 2019, and a typical day was chosen for each month (19 June, 17 July, 22 August, and 15 September). The study revealed that the highest efficiency of the solar water collector obtained at the highest value of the intensity of solar radiation at mid-day. The maximum thermal efficiencies achieved on 17 July of 2019 were about 67% and 66% based on theoretical and experimental analyses, respectively. A simultaneous increase in the water temperature and the intensity of solar radiation have been observed. During the four typical days of the experiment, the highest water temperatures of the solar collector were recorded during midday, i.e., $57.2,64.4,52.4,\mathrm{and}\ 49{}^{\circ}\mathrm{C}$at the inlet, and $62.8,71,57.4,$and $53.2{}^{\circ}\mathrm{C}$) at the outlet for 19 June, 17 July, 22 August, and 15 September 2019, respectively, while the solar radiation intensities recorded are $957,1022,840,\mathrm{and}\ 723\ \mathrm{W}/{\mathrm{m}}^2$ for the test days.

Review on the Progress of Solar Water Heaters and Their Future Perspectives

“…[51,52] Many researchers commonly utilize the following mathematical equations to evaluate the performance of SWH systems. [51,[53][54][55][56][57][58] These equations are supplemented with empirical data gathered from real-world experiments, which are then integrated into the equations for analysis and evaluation purposes. By employing these mathematical equations in conjunction with actual experimental data, researchers can obtain valuable insights into the performance and effectiveness of SWH systems.…”

“…It is necessary to understand the parameters affecting the thermal performance of SWH. [53,54] Figure 3 shows the correlation of the energy equation for the theoretical investigation of the SWH flat-plate collector. The equations include calculation and operational parameters such as absorbed solar energy radiation and temperatures of the SWH collector for simulation purposes or theoretical investigations.…”

“…Alwan et al [ 54 ] examined the reliability of the above equation. The theoretical model proved reliable in understanding the thermal behavior of the flat plate SWH with a discrepancy of 4.7%.…”

“…Therefore, users can get a minimum of lower costs after 4 years. Alwan et al [ 54 ] conducted an investigation theoretically stating that the economic analysis of payback SWH is 235 days. From a market perspective, the type used is active SWH which requires a pump to maximize the circulation of liquid fluid flow.…”

“…The various technical constraints of the current SWH can be an advantage as an improvement material to improve the thermal efficiency of the SWH concerning the design, components, and operating conditions. [ 54 ] For example, nanofluid utilization can increase thermal efficiency by up to 87%. Another obstacle is in sedimentation form [ 81 ] used as material for other studies, such as modifying the manifold shape.…”