Tube-sheet core device for flat-plate solar collectors

Abstract

The invention discloses a tube plate type core device of a flat-plate solar collector and belongs to the technical field of flat-plate solar collectors. The tube plate type core device comprises a pair of round guide collecting tubes with large tube diameters, a plurality of heat absorption row tubes with small tube diameters and a flat-plate absorber plate with an absorption layer on the surface. The guide collecting tubes are provided with a plurality of connection rings which are arranged at intervals. The heat absorption row tubes are special-shaped tubes with flat top surfaces. Each heat absorption row tube has a longer main-body middle section and two shorter same-direction bending sections. A port of each bending section is provided with a round insertion port. The round insertion ports are respectively inserted in corresponding connection rings and are in brazed connection with the connection rings. The flat top surfaces of the heat absorption row tubes and the top edges of the guide collecting tubes are integrally located on the same plane. An ultrathin and continuous heat conduction silica gel layer is adhesively bonded on the back plane of the flat-plate absorber plate. By means of the technical scheme, the tube plate type core device is high in heat transfer property, no damage is caused to absorption films, bonding area is large and full contact is achieved, the flat-plate absorber plate is large in heat utilization area, and heat transfer is conducted evenly between tube plates.

Description

【Technical field】 [0001] The invention relates to a tube plate type plate core device of a flat solar heat collector, belonging to the technical field of flat solar heat collectors. 【Background technique】 [0002] The plate core device is a core component of the flat solar collector, which plays the role of heat absorption and heat transfer, and its structure and performance directly determine the thermal performance of the flat solar collector. The plate core device is mainly composed of heat-absorbing pipes, diversion headers and a flat heat-absorbing plate with a solar selective absorption film on one side. Divided into laser spot welding and ultrasonic welding. [0003] In the prior art, the heat-absorbing exhaust tube of the tube-sheet type plate core device adopts a circular copper tube, and the flat heat-absorbing plate is an aluminum flat heat-absorbing plate, and the heat-absorbing exhaust tube and the flat heat-absorbing plate form contact lines. Take the contact...

AI Technical Summary

Problems solved by technology

[0003] In the prior art, the heat-absorbing exhaust tube of the tube-sheet type plate core device adopts a circular copper tube, and the flat heat-absorbing plate is an aluminum flat heat-absorbing plate, and the heat-absorbing exhaust tube and the flat heat-absorbing plate form contact lines. Take the contact line as the baseline and complete the connection between the heat absorbing pipe and the flat heat absorbing plate by laser spot welding on both sides of the pipe, leaving a gap between the welding points, and welding the circular heat absorbing pipe and the flat heat absorbing plate The final contact area is theoretically a linear contact, and the contact area is small. The heat transfer connection formed by the intermittent welding theoretically makes the heat energy absorbed by the flat heat absorbing plate conduct heat conduction according to the theoretical contact line and the solder joint, and the contact The small area leads to low heat transfer efficiency, and in the actual welding process, the two welded workpieces, the wider and thinner flat heat absorbing plate and the circular heat absorbing pipe, have certain flatness defects objectively, and batch welding is difficult to avoid Operation errors occur, so it is difficult to maintain continuous contact between the tube and plate and obtain uniform heat transfer performance. The base material of the flat heat absorbing plate is aluminum, and the heat absorbing exhaust pipe is copper pipe. The energy per unit area required for the welding of the two Different, so it is difficult to overcome the occurrence of bad welding phenomena such as desoldering and virtual welding. Although laser spot welding is carried out on the back of the flat heat absorbing plate, that is, the opposite side of the solar selective absorption film layer, due to thermal processing, will still cause a certain degree of damage to the film

[0004] Ultrasonic welding works under pressure, especially when welding will produce a huge reciprocating acceleration, and its force will make the thinner flat heat-absorbing plate substrate and film layer (thickness is only 0.4mm respectively) , 0.12mm) produces yield deformation, which leads to damage to the solar selective absorption film layer, and the ultrasonic wheel will also cause a certain degree of wear to the absorption film layer, reducing the absorption capacity of the flat heat absorbing plate for solar energy, and welding after yield deformation The joining force is weak and the reliability is poor. The line surface contact welding method also has the disadvantages of small heat conduction area, which is not conducive to heat exchange and low heat conduction efficiency.

Images