Development and experimental research of solar air collector

In the article, the thermal energy balance of a laboratory-research room with a total area of 30 m2 and a volume of 60 m3 is compiled. The research was conducted on January 5, 2023. Coordinates of the research site Latitude - N = 40.42584°, Longitude - E = 71.76826°. Azimuth angle 119.85 degrees at sunrise time 738 hours was 1218 hours. When the heat balance of the laboratory-research room was drawn up, the external temperature decreased from -2 °C to -12 °C, correspondingly, it was observed that the heat loss of the laboratory-research room was from 7,8 kW to 10,6 kW. The reason for the sharp increase in energy consumption was that the house was built without meeting the standards of heat dissipation. In order to reduce energy consumption, a solar air cooler collector was installed on the side of the laboratory-research building and the results were obtained. As a result of the installation of a solar air heater collector with a working surface of 1 m2, it was experimentally determined that the daily energy consumption is reduced by 1,43 kW.

Basing the fuel saving and environmental performance of solar air heater collectors

Toxirov,

Uzbekov,

Boynazarov

et al. 2024

The influence of artificial turbulization on the efficiency of heat exchange in the channels of solar air heating collectors

Uzbekov,

Boynazarov,

Madaminov

et al. 2024

This article presents a review and analysis of the results of experiments and theoretical studies on the effect of artificial turbulization on the efficiency of heat transfer in channels. The main factors influencing heat transfer are considered, such as the size and shape of the turbulators, their orientation relative to the direction of flow, as well as the hydrodynamic features of the flow. Empirical relationships for assessing the efficiency of heat transfer are discussed and the results of experiments with various types of turbulators are presented. Directions for further research are proposed, including numerical modeling and optimization of geometric turbulators. Based on the analyses, a method is proposed to obtain an empirical heat transfer formula for SAH with V-shape and metal shavings absorbers. Based on the principle of superposition, an analytical expression is derived to calculate the efficiency of solar absorbers made of metal shavings and a Vshaped surface compared to a smooth surface.

Study of hydrodynamic and thermal parameters of the air flow of a solar air heating collector

Uzbekov,

Boynazarov,

Madaminov

et al. 2024

In this study, the thermal and hydraulic characteristics of the air flow over the metal shavings of the absorber of a solar air heating collector were analyzed. During the study, formulas were derived for calculating the temperature and hydrodynamic parameters of the flow. The air flow temperature, boundary layer thickness, local friction stress on the chip surface and other important parameters were determined. Calculations were performed for various flow rates and Reynolds numbers. The results obtained made it possible to evaluate the influence of metal shavings on the characteristics of the air flow. It was shown that the thickness of the boundary layer decreases with increasing Reynolds number, which is consistent with hydrodynamic theory. A comparison was also made of the thermal resistance for a smooth surface and a surface with metal shavings. The results showed that the use of metal chips could reduce the thermal resistance, which could be beneficial for improving the heat transfer efficiency in solar air heating collectors.