До питання підвищення ефективності розрядних характеристик акумуляторів теплоти на основі акумулюючих матеріалів фазового переходу

Анотація

UDC536.248.2

QUESTIONS TO INCREASE EFFICIENCY OF heat accumulatorsdischarge characteristics BASED MATERIALS accumulating phase transitions

V. Gorobets, I. Antypov, V. Trohanyak, Y. Bogdan

Intensifying heat selection accumulating heat accumulating in the deep layers of the material as possible in the application of the so-called reinforced structures and the application of cellular structures. The authors of the studies conducted a series of studies on intensification of heat transfer through the use of advanced heat transfer surfaces, leading to increased efficiency, compared to a smooth surface.

The purpose of research – efficiency discharge characteristics of heat accumulators from heat accumulating phase change material.

Materials and methods of research. Using unconventional solutions to improve the efficiency of the heat accumulator discharge characteristics, proposed setting internal (multi) electric heating elements in the middle of the heat accumulator casing near the heat (or under) the elements of heat exchange surface. The said, will create a layer of molten (liquid) soothes, thermal conductivity is much greater than in the solid state, and thus intensify the process of selecting accumulated heat from deep layers of the material.

As additional multilevel heating elements used self-regulating electric heating cables brands Devi-Hotwatt 55 that are used to maintain the temperature of hot water in domestic pipes at 55 °C, which not only eliminates the need for constant circulation of hot water for «charging» circuit, but also extends the technological capabilities of storage heat accumulator using such devices in systems with combined use of energy.

Results of research. An additional study for two heating elements located adjacent to the lower surface of the wall heating pipes but spaced bases on the corners of an equilateral triangle equivalent. His analysis shows that the installation of two (paired) heating elements reduces the temperature in the layer heat-accumulating material in the initial period and further stabilization at 55 °C, while in the heat accumulator heat with a single heating element through the same period of time (120 min), observed mainly around lowering the temperature soothes heat exchange surface. Save thus soothes liquid layer around the heat exchange tubes to some extent improves the selection process accumulated heat from its deep layers, because thermal conductivity of liquid accumulating material much higher than in the solid phase transition soothes. Thus, there is a more intensive process of outflow of accumulated heat from the inner layers accumulating material toward the surface heat transfer efficiency of selection of heat from deep layers, thus, increased by 8–10 %. In addition, time efficient operation of the heat accumulator in the «discharge» increased by 86 %.

Conclusions

1. To increase the efficiency of the heat accumulator discharge characteristics of heat on the basis of phase transition found a new technical solution to route from internal installation (multi) heating elements in the middle of the housing of the heat accumulator.
2. Efficiency of selection of heat in the deep layers in the battery design with improved heat paired heating elements increased by 8–10 %. At the same time efficient operation of the battery in the «discharge» increased by 86 %.
3. As a result of the studies, the reported optimal placement distance electric heating elements heat inside the battery, as well as their overall performance.