Как выбрать гостиницу для кошек
14 декабря, 2021
Q |
(8) |
AT Ztotal |
The closed two-phase thermosyphon is an effective heat transfer device. The working principle can be easily explained as obtaining heat from the evaporator section by means of the evaporating mechanism and then releasing the heat out of the condenser section by means of the condensing phenomena. Because the latent heat of vaporization of the working fluid is relatively high, a large amount of heat can be transported through the thermosyphon.
where AT is the effective temperature difference between the heat source and the heat sink
(9) |
AT = Tso — Tsi — ATh
ATh = ‘ p |
(Tp — Tv)x F |
(10) |
Where Tso is the heat source temperature,(oC), Tsi is the heat sink temperature,(oC) and the mean temperature difference due to hydrostatic head, ATh is given by
Where the saturation temperature at the bottom of the pool, Tp is given by |
P v |
(11) |
dH L |
(12) |
Tv — Tsi + |
^ Z7 + Z8 + Z9 (t _ T ) so si |
total |
(13) |
For the vapor temperature of the working fluid, Tv is determined from
Where Ztotal is the overall thermal resistance of the thermosyphons, it can be represented by the idealized network of thermal resistances Z1 to Z10 as shown in Figure 4.
Z1 M+MV |
Z9 |
Z10 |
Z4 |
Z5 |
AV |
z1,z9 Convection z2,z8 Convection z3,z7 Internal resistance
of boiling & condensing z5 Pressure drop
z10 Thermal conduction
resistance axially z4,z6 Vapor-Liquid internal
Z3f |
t Z3p ► Z2 |
Condensate |
AV |
Z10 |
Z1 |
Z9 |
Z6
Fig 4.Thermal resistance and their locations.