Prototype of Integrated Collector Storage Using Phase Changes Material and Thermosyphon Heat Pipes
Abstract
Conventional thermal solar systems consist of roof-mounted collectors, a storage tank inside the building and various elements that ensure the operation of the system (controller, pump, etc.). This ultimately leads to relatively complex systems, leading to major disadvantages such as a relatively high cost, storage volume footprint and maintenance. The development of "passive" solar systems is therefore a strategy to be favored. It is in this context that we have studied numerically and experimentally a new concept of integral collector storage with phase change materials and heat pipes. A prototype was tested in real conditions at INES. Thermosiphon heat pipes work very well by transferring the absorbed solar energy to the storage located at the back of the absorber, and by acting as a thermal diode. Concerning storage, a small difference in temperature is observed between the 2 faces of the cavity containing the phase change material, which shows the efficiency of the honeycomb to transfer the heat. In terms of performance, the prototype is very well placed for its productivity. However, storage is largely discharged at night. This implies a low annual solar fraction. The metallic fixation which maintains the cavity is largely responsible for these losses. It is therefore sufficient to limit the thermal bridges to greatly improve the solar fraction.