Method of creating an optimum heat exchange in an assembly comprising a thermally-conductive absorbent plate and a heat-transfer fluid

Abstract

The invention relates to a method of optimising heat exchanges between (i) a thermally-conductive absorbent plate (1) which is exposed to thermal radiation and a heat-transfer fluid (3) circulating in at least one thermally-conductive conduit tube (2) that is in thermal contact with the plate (1) and (ii) within the heat-transfer fluid (3). The invention is characterised in that, in order to promote heat exchanges, the method uses zones of the aforementioned plate (1) in order to form part of the wall of the conduit tube (2), such that the heat-transfer fluid (3) is in direct contact with the plate (1) so as to reduce the thermal resistance between the plate (1) and the heat-transfer fluid (3) circulating inside the conduit tube (2), said conduit tubes (2) being disposed on the two faces of the plate (1) and being interconnected by means of holes (4) that provided on the plate.

Description

technical field [0001] [01] The object of the present invention is to propose a method capable of ensuring optimum heat exchange within a package consisting of a heat-conducting absorber plate and a heat-carrying fluid flowing in at least one heat-conducting tubular channel. It finds particular, but not exclusive application in heat collector tubes of solar panels. Background technique [0002] [02] The heat collecting tube of known solar cell panel comprises: [0003] [03] A plate, usually of copper or aluminum, the upper surface of which is covered with a selective layer which facilitates the absorption of sunlight; [0004] [04] A pipe with a circular cross-section, which is welded on the lower surface of the plate, usually copper or aluminium; [0005] [05] • A heat transfer fluid flowing in said conduit. [0006] [06] In the manner described, sunlight hitting the upper surface of the plate is converted into heat which is conducted to the weld zone and then to the pip...

AI Technical Summary

Problems solved by technology

[0009] [09] The heat transfer fluid has weaker thermal conductivity than copper, and the transfer of heat from the liquid near the pipe wall to the center of the liquid cannot be optimal

[0010] [10] Therefore, the flow of the heat-carrying fluid in the pipe is laminar and the distribution of temperature is uneven. For this reason, the temperature of the heat-carrying fluid decreases from the upper layer close to the pipe wall to the center of the pipe. Suboptimal heat exchange within and between pipes and heat transfer fluid

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