Numerical and empirical evaluation of a novel building integrated collector storage solar water heater

Abstract

Integrated collector storage is a long established simple low cost solar water heater configuration combining the solar collector with a storage tank into a single unit. Previous studies have shown the potential of integrated collector storage solar water heaters to significantly reduce domestic energy requirements for water heating, however challenges still remain to integrate them in roof/façades and ensure appropriate domestic hot water demand. In this article, a novel integrated collector storage solar water heaters is being investigated. The configuration and geometry proposed incorporates an embedded heating element to provide a self-contained domestic hot water system and consider roof integration restriction allowing the unit to be embedded within a structural insulated roofing panel system. The proposed system also utilizes an inlet diffuser designed to reduce the disruption to the stratification within the storage during and following draw-off. This article presents a Computational Fluid Dynamic analysis of internal flows and heat transfer regimes within this new collector configuration and compares its performance against previous developed prototypes using empirical testing. The increased aspect ratio of the new design was shown to significantly alter the heating and cooling characteristics of the collector, both gaining and loosing heat at a greater rate than the original prototype. The computational analysis showed that the collector charges effectively with some stratification. Higher draw-off rates however resulted in higher bulk water outlet temperatures, providing better energy delivery efficiency. The inlet diffuser was also shown to improve the thermal efficiency of the unit overall. The empirical testing shows the improvement in performance of this novel integrated collector storage solar water heaters against previous developed prototypes. The study highlights the need to review the effect of draw-off regime upon the performance of such systems in order to identify optimal regime and control strategy.

Performance analysis of the new design of photovoltaic/storage solar collector

“…They include the starting inlet water temperature, heat losses, solar radiation intensity, ambient temperature, humidity, wind velocity, and other prevailing weather conditions. The starting inlet temperature and heat losses are changes during the year . It also noted that the temperature of the mean storage temperature is higher in the second model than the first model.…”

Functionality assessment of building a micro-climate system utilising solar energy in a cold climate

“…Heat storage is an important part of a solar collector system, which helps to manage differences in time, as well as between the use and production of heat. Study [32] analysed the contribution of solar-thermal and thermal energy storage systems to fulfilling thermal energy demand profiles. 48 case studies used 12 house types under average (smoothed) and actual (warmer) weather conditions, as well as continuous and intermittent comfort maintenance.…”

A Novel Adaptive Neural MPPT Algorithm for Photovoltaic System

“…Each string is formed of a specific PV module number connected in series in order to obtain the required voltage. PV modules are built by connecting solar cells in series with the purpose of getting a sufficient voltage level and increasing the nominal power of the PV array system [18]. The equivalent model of a PV cell is shown in Figure 1.…”

“…I sc is cell short circuit current at reference temperature and irradiation. The ki, Tr and T are short-circuit current temperature coefficient, cell reference temperature and solar irradiation respectively [17][18].…”