SE525680C2 - Tube heat exchanger is for air to air and comprises series-coupled exchanger packets, each incorporating parallel-coupled flat tubes all laterally displaced both longitudinally and crossways - Google Patents

Abstract

The tube heat exchanger is for air/air and comprises series-coupled exchanger packets (1), each incorporating parallel-coupled flat tubes (2), all laterally displaced both longitudinally and crossways.

Description

The tubes are further joined according to Figures 3 and 4 along their orifices, which are formed by widening the sheet material into widened rhomboid-shaped orifice surfaces 23. The joining takes place with a combination of sealing compound 31 and a folding sheet metal sheet 24 cut from the laterally displaced surface widths. "Corresponds to the sum of the gap width" a "within the tubes and the gap width" b "between the tubes. With gap widths in the order of 6-8 mm, experience has shown that few problems with contamination are achieved.

Said lateral displacements are made in the tube direction suitably in size as the tube gap "a" and across the tube direction as the gap width "b".

Figure 5 illustrates in a section of the exchanger package 1 flow of a first air fl destined 5 across the tubes 2 and overflow to adjacent exchanger package 1 “. Due to the lateral displacement of the tubes, both a widening of the gap orifices is obtained, which minimizes the inflow and outflow resistances, and a maximum of short transport distances while maintaining air speed between the exchanger packages. With the mentioned gap widths and air speeds of approx. 3 m / s, experience has shown that the total pressure drop in the gearbox package and the overflow is approx. 6 mm vp.

The same flow advantages are obtained for a second air flow 6, driven within the tubes in reference to fi gur 6.

An optional number of equal gear packs are mounted within a box-shaped housing 4 with every other packet rotated half a turn about an axis of rotation perpendicular to the plane surfaces 21. The air flows 5 and 6 are driven in countercurrent through the series-connected packets. Pressure drop in the air overflow between the packages is minimized as well as the space requirements for the overflow. A relationship between number of packages and efficiency is as follows Number of packages 1 2 3 4 5 Efficiency% 45 62 71 76 80 50 66 75 80 83 In Figures 7 and 8, the invention is illustrated with 4 series-connected exchanger packages and a total very reasonable pressure drop for air fl fates if ca 24 mm vp. Figure 7 shows flow of air 6 through the tubes and inlet 61.62 in the housing. Circles 7 mark seals made around the myrmins of the gear packages partly with each other and partly against the housing. Figure 8 shows countercurrently driven flow of air across the tubes via inlet / outlet 51.52. The packages 1 are slightly laterally offset from each other, abutting the housing 4 with seals 7, marked with circles. Triangular plates, not »u _) 525 fwf fi i shown in the figures, delimit the overflow of the second air fl between the exchanger packages l.

A prerequisite for a compact assembly of the exchanger packages is that its depth B is small in relation to the average value A of width and length of the planar surface 21. The volume of the exchanger body is A2 B and its space within the housing (A + B / 2) 2 B, which means that the volume of the housing essentially increases with the ratio B / A relative to the package volume. If a limit for the quota is set, for example, at 30%, this also entails practical limits for air capacity.

An excellent sheet material for smaller exchangers is used offset sheet in 0.3 mm hard aluminum in cut format of approx. 0.7 x 1.0 m, which gives a flat surface of 0.5 x0.7 m and A = 0.6 m, W max = 0.2 m, maximum front surface for the column theme = 0.06 m2 and maximum air speeds with speeds of 3 m / s of approx. 600 kbm / h. This type of sheet metal can be advantageously used, for example, for residential ventilation with air flows in the register 300 - 600 kbm / h.

A practically possible upper limit for the plane surface 21 can be l xl m with A = 1 m, B = 0.3 m, front surface for the gaps = 0.15 m2 and air fl deserts with speeds of 3 m / s of about 3,000 kbm / h.

Depending on how the air beads 5 and 6 are driven by pressure or suction through the exchanger packages 1, these are provided with spacers arranged inside or between the tubes 2 for accommodating local pressure differences between the beads. The spacers may, for example, be slit-high, hat-shaped sheet metal profiles glued to a flat surface 21 in the tube direction within the tubes or across the tube direction on the outside of the tubes.

Claims (1)

1. D.) -f -H- rn I ~ J L? G \ .b (t: (f) Patent claim Tube guard exchangers for air / air comprising series-connected heat exchanger packages (1) each consisting of parallel-connected flat tubes (2) with rectangular flat surfaces (21) and the tube orifices (22) interconnected by air. each heat exchanger package is in the form of an oblique prism with the planar surfaces as bases in that the tubes are laterally displaced both along and across the tube direction. Tube heat exchanger according to claims 1-2, characterized in that it comprises said exchanger package (1) mounted in a box-shaped housing (3) with every other package rotated half a turn, with the packages interchanged along the tube mouths (22). ) and with the packages abutting and sealed against the casing. the sheet packages (1) are displaced laterally laterally across the tube direction. Tube heat exchanger according to claims 1-4, characterized in that it comprises as off sheet material in said tubes (2) used offset sheet in 0.3 mm aluminum in cut format of about 0.7 x 1.0 m.