SELF-ACTING AND SELF-REGULATING CIRCULATING PUMP POWERED BY LOCAL HEAT INSTEAD OF ELECTRICITY FOR SOLAR INSTALLATIONS

摘要

A new technology for heat-transfer agent circulation in the flow circuit of a solar installation is proposed in this article. Devices that are built according to this technology can be called "two-phase reverse thermosyphons with two work-agents". A new innovation is the use of two substances for doing two different actions. Liquid water or its solutions are used for heat transfer and the vapour of a low-boiling substance (such as pentane or butane) is used to force circulation of the heat-transfer agent in the loop. In comparison with other known reverse thermosyphons, a very small quantity of a low-boiling substance (about 10-40 g per 1 kW of heat transfer power) is needed to create the vapour and force circulation. Thanks to this new technology, solar installations do not need electrical circulating pumps with control systems and they can be independent from any power grid. Full-sized experimental examples of the devices have been successfully tested under laboratory conditions and in combination with an experimental solar installation. Such devices have good perspectives for practical use.