29
CORRECTION FACTOR FOR THE USE OF GLYCOL
Correction factor for the use of glycol IN HEATING MODE
ETHYLENE GLYCOL
with water produced between 30 ÷ 55 º C.
PROPYLENE GLYCOL
with water produced between 30 ÷ 55ºC.
Percentage Of glycol in mass / volume
0 / 0
10 / 8.9
20 / 18.1
30 / 27.7
40 / 37.5
Freezing point [°C]
0
-3.2
-8
-14
-22
Heating capacity CCPF
1.000
0.995
0.985
0.975
0.970
Power input CCPA
1.000
1.010
1.015
1.020
1.030
water flow rate CCQA
1.000
1.038
1.062
1.091
1.127
water pressure drop CCDP
1.000
1.026
1.051
1.077
1.103
Percentage Of glycol in mass / volume
0 / 0
10 / 9.6
20 / 19.4
30 / 29.4
40 / 39.6
Freezing point [°C]
0
-3.3
-7
-13
-21
Heating capacity CCPF
1.000
0.990
0.975
0.965
0.955
Power input CCPA
1.000
1.010
1.020
1.030
1.040
water flow rate CCQA
1.000
1.018
1.032
1.053
1.082
water pressure drop CCDP
1.000
1.026
1.051
1.077
1.103
Based on DESIGN CONDITIONS from the table “performances” extract Cooling Capacity (kWf) and Compressors Power Input
(kWa).
Based on type and percentage of glycol extract CCPT, CCQA, CCDP.
Then calculate.
Pt_brine = kWt
r
x CCPT
Then calculate brine flow rate to the heat recovery exchanger:
Q_brine [l/s]=CCQA x (Pt_brine [kW]*0.86/
∆
T_brine)/3.6
where
∆
T_brine is the temperature difference outlet-intlet heat recovery exchanger:
∆
T_brine=Twout_brine-Twin_brine
With this brine flow rate enter in abscissa on the water pressure drop of the heat recovery then you have Dp_app.
Finally you can calculate the actual pressure drop of the brine on heat recovery:
Dp_brine =CCDP x Dp_app
Correction factor for the use of glycol IN COOLING MODE
ETHYLENE GLYCOL
with water produced between 5 ÷ 20 º C.
PROPYLENE GLYCOL
with water produced between 5 ÷ 20 º C.
Percentage Of glycol in mass / volume
0 / 0
10 / 8.9
20 / 18.1
30 / 27.7
40 / 37.5
Freezing point [°C]
0
-3.2
-8
-14
-22
Cooling capacity CCPF
1.00
0.99
0.98
0.97
0.95
Power input CCPA
1.00
1.00
0.99
0.99
0.98
water flow rate CCQA
1.00
1.04
1.08
1.12
1.16
water pressure drop CCDP
1.00
1.08
1.16
1.25
1.35
Percentage Of glycol in mass / volume
0 / 0
10 / 9.6
20 / 19.4
30 / 29.4
40 / 39.6
Freezing point [°C]
0
-3.3
-7
-13
-21
Cooling capacity CCPF
1.00
0.98
0.96
0.94
0.92
Power input CCPA
1.00
0.99
0.98
0.95
0.93
water flow rate CCQA
1.00
1.01
1.03
1.06
1.09
water pressure drop CCDP
1.00
1.05
1.11
1.22
1.38
Based on outdoor air temperature and leaving water temperature of the evaporator (DESIGN CONDITIONS) from the table
“performances” extract Cooling Capacity (kWf) and Compressors Power Input (kWa).
Based on type and percentage of glycol extract CCPF, CCPA, CCQA, CCDP.
Then calculate.
Pf_brine = kWf x CCPF
Pass_CP_brine = kWa x CCPA
Then calculate brine flow rate of the evaporator:
Q_brine_evap [l/s]=CCQA x (Pf_brine [kW]*0.86/
∆
T_brine)/3.6
where
∆
T_brine is the difference inlet-outlet evaporator water temperature:
∆
T_brine=Twin_evap_brine-Twout_evap_brine
With this brine flow rate enter in abscissa on the water pressure drop of the evaporator then you have Dp_app.
Finally you can calculate the actual pressure drop of the brine on evaporator side:
Dp_evap_brine =CCDP x Dp_app
Fouling factors
The performances supplied with the tables are referred to a fouling factory = 0.44x10
-4
m² K/W . For different values of the fouling
factory, use the reduction coefficients reported in the following table.
F.c. PF:
Correction Factor for Cooling capacity
F.c. PA:
Correction Factor for compressor power Input
Fouling factory
Evaporator
F.c. PF
F.c. PA
(m² K / W)
0.44 x 10
-4
1
1
(m² K / W)
0.86 x 10
-4
0.98
0.99
(m² K / W)
1.72 x 10
-4
0.93
0.98
Summary of Contents for RHA series
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