AERMEC NRL, Technical Manual Installation Maintenance

Page: 28 / 48

16. TOTAL RECOVERY
In case of operation with total heat
recovery, the machine performances
do not depend on the external air
temperature but on that of the hot water
produced:the electrical input power
and the recovery heating capacity are
obtained by multiplying the values (Pa,
Pr) shown in table 16.1.1 by the respective
correction coefficients (Ca, Cr), that
can be seen in the following diagrams.
According to the temperature of the
hot water produced referred to is shown
assuming a difference of 5°C between
the inlet to and outlet from the total heat
recovery unit.
The cooling capacity (Cc) is obtained from
the difference between recovery heating
capacity (Cr) and input power (Ip).
The nominal value refers to:
− air temperature 35°C
− water at the desuperheater 50°C
− ∆ t 5°C
Processed water temperature (°C)
35°C
40°C
45°C
50°C
55°C
5
0.9
1.0
1.1
1.2
1.3
1.4
1.5
6 7 8 9 10 11 12 13 14 15 16 17 18
CORRECTION COEFFICIENTS OF THE RECOVERED HEATING CAPACITY
Processed water temperature (°C)
CORRECTING COEFFICIENTS OF INPUT POWER WITH RECOVERY
35°C
40°C
45°C
50°C
55°C
5
0.7
0.8
0.9
1.0
1.1
1.2
6 7 8 9 10 11 12 13 14 15 16 17 18
0,0
20,0
40,0
60,0
80,0
100,0
120,0
140,0
160,0
180,0
200,0
0 50000 100000 150000 200000 250000 300000 350000 400000
Portata acqua [l/h]
P
e
rd
it
a
d
i c
a
ri
c
o
t
o
ta
le
[
k
P
a
]
2800
3000
3300
3600
TOTAL PRESSURE DROPS RECOVERY
Average water temperature °C 30 40 50
Multiplicational coefficient 1.04 1.02 1
16.1.1. Correction of pressure drop when
average water temperature varies.
Ca
Cr
280 300 330 360
Heat capacity recovered kW 945 1060 1152 1244
Total input power kW 263 295 320 345
Water flow rate recovery l/h 162500 182320 198160 214010
Pressure drop recovery exchanger kPa 60.4 66.9 65.9 68.2
16.1. PRESSURE DROP
The NRL models with total heat recovery
always have 1 heat recovery unit.
The characteristics of the heat recovery
units and the pressure drop curves are
shown below; the filter leakage is not
covered.
The pressure drops in the diagram refer
to the average water temperature of
50 °C.
The table 16.2.1. shows the correction to
be applied to the pressure drops when
the average water temperature varies.
NOTES:
Using total recovery is only allowed in
the cooling operation.
The units with total recovery (T) are not
available in the versions:
− YT
− XT (only for temperature lower than 4°C)
16.1.1. NRL (T)
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INRLPY. 02.10 4086916_01