填料塔英文献和中文翻译(3)

tower to determine the moisture content change and the tempera-
ture variation for both the air and the solution. A detailed error
analysis indicated an overall accuracy within 610% of humidity
change and within 620% of solution concentration change.
3 Results
Two different sets of experimental tests were carried out: the
ﬁrst included 20 dehumidiﬁcation runs with H2O/LiBr and 26with H2O/KCOOH; the second, 26 regeneration runs with
H2O/LiBr and 12 with H2O/KCOOH. When the partial vapor
pressure on the air side was higher than that on the desiccant side
a dehumidiﬁcation process occurred, on the contrary a desiccant
regeneration process was obtained. Table 2 gives the main opera-
tive conditions under experimental tests: air inlet temperature Tai
and humidity ratio Yi
, solution inlet temperature Tsi
and concen-
tration Xi
, air mass ﬂux G/S and solution mass ﬂux L/S, ratio
between solution L and air G mass ﬂow rates. The air mass ﬂuxes
investigated during experimental tests are set to ensure zero-
carryover conditions and they result lower than the values usually
applied in commercial units. As can be seen, regeneration condi-
tions during experimental investigation were obtained by increas-
ing solution and air inlet temperature up to values around 50 °C.
Figures 2~a! and 2~b! show the humidity reduction measured
during the dehumidiﬁcation runs against the mass ﬂow rate ratio
L/G. The dehumidiﬁcation rate depends on the ﬂow rate ratio with
a logarithmic trend, the slope of which increases, in absolute
value, with the air inlet humidity ratio. The solution H2O/LiBr
shows better dehumidiﬁcation performance than the
H2O/KCOOH solution. The measured humidity reductions are in-
teresting for the application to air conditioning or drying
processes.
Figures 3~a! and 3~b! show the solution concentration increase
measured during the regeneration runs versus the mass ﬂow rate
ratio L/G. The regeneration rate depends on the ﬂow rate ratio
with a logarithmic trend, the slope of which decreases with the air
inlet humidity ratio. The solution H2O/KCOOH shows better re-
generation performance than H2O/LiBr solution.
The performance of a dehumidiﬁcation/regeneration tower can
be evaluated by a speciﬁc tower efﬁciency as the ratio between
the absolute value of the actual humidity change on the air side
and the absolute value of the maximum humidity change possible
under given conditions:
«tower5uYi
2You/uYi
2Yo.min/maxu
The maximum humidity change is achieved when the partial va-
por pressure of the air at the outlet is equal to the saturation
pressure of the solution at the inlet of the tower. This efﬁciency is
valid both for dehumidiﬁcation and regeneration tests.
Figures 4~a! and ~b! show the tower efﬁciency for the experi-
mental tests carried out. The efﬁciency increases with the mass
ﬂow rate ratio, with a similar trend for dehumidiﬁcation and re-
generation tests but with a different absolute value. Dehumidiﬁ-
cation efﬁciency ranges between 40 and 80–90% with a ﬂow rateratio ranging from 0.2 to 3.0, whereas regeneration efﬁciency var-
ies from 25 to 75% with a ﬂow rate ratio ranging from 0.3 to 3.0.
The experimental results are also compared to a one-
dimensional simulation code of an adiabatic packed tower de-
scribed in @13#. The whole absorption/desorption column is sub-
pided into an appropriate number of sections, and suitable
subroutines were realized to evaluate heat and mass transfer coef-
ﬁcient in accordance with @6,8,9#. Initial assumptions on outlet
conditions can be veriﬁed and adjusted by iteration. The model 填料塔英文献和中文翻译(3):http://www.751com.cn/fanyi/lunwen_13304.html