PROJECT:
INTEGRATED COLLECTOR STORAGE WITH MOVABLE INSULATION LAYER

Research and development on renewable energy are increasing day by day to fight against climate change and global warming that we feel more closely nowadays. Solar energy is employed in DHW heating with solar thermal collectors, which is one of the most critical figures in renewable energy and can generate more energy than the world requires. Integrated collector storage system (ICS), which is the first example of solar thermal collectors, is an essential tool that can enable solar energy to become widespread in the world due to its low cost, easy installation and use. In order to minimize the most significant disadvantage of the ICS, which is thermal losses at night, numerous academic investigations and designs have been analyzed. In this study, an electronically controlled movable insulation layer is included in the ICS system to both minimize thermal losses and prevent the average heat transfer temperature in storage from reaching dangerous levels. The corrugated heat exchanger, which provides approximately two times more heat transfer area than the straight one with the same pipe length, was included in the system. The overall dimensions of the integrated collector storage system with movable insulation layer (ICSWMI) were determined according to the heat exchanger serpentine and the outer roll diameter of the movable insulation layer.

The findings of the designed ICS system based on solar-thermal calculations are covered in this study: based on the research conducted prior to beginning the design, it was determined that the ICS system should be low-cost, simple to install, and, most significantly, that heat loss should be kept to a minimum while heat gain is maximized. A rectangular ICS system, which does not require a circulation pump and uses natural convection to transfer heat, was shown to be a low-cost and simple-to-install solution; at the same time, it is anticipated that the final design would also meet aesthetic criteria, which will be a significant benefit in view of its possible future large-scale commercialization. Moreover, a movable insulation layer is considered into the collector design in order to reduce heat losses from it: it is self-evident that, by positioning the movable insulation layer between the glazing and the absorber, this layer will be protected from external influences to the greatest extent feasible. Finally, since prior researches were based on manual control solutions for the mobile insulation, it is decided that the system could be electronically controlled, as this feature may be improved in a prototype version of the collector.

Figure1. For simplicity, ICSWMI was designed to have a rectangular shape. Electronic units such as Arduino, thermal sensors, and some parts of DC motors will be installed in the movable insulation enclosure.

Figure2. Thanks to time-constraint data installed in Arduino, depending on the sunrise and set hours, the movable insulation layer will be initiated.

The thermal model of the ICSWMI consists of three heat transfer mechanisms: conduction, radiation and convection. There are two cavities in the ICSWMI system: the air cavity, which is between the absorber plate and glazing, and the antifreeze mixture , which is the water-glycol mixture inside the storage tank.