Figure 8. Averaged day operating cycle of the experimental adsorptive heat pump
Adsorber was filled with 10 kg of the composite ‘silica gel – sodium sulphate’.
Mineral wool with thickness of 100 mm and heat conduction coefficient 0.035 W/m·K
was used as heat insulator. The adsorbent was regenerated at night from 0.00 to 8.00
a.m. In a day time discharge is performed. So, heat pump supplied heating system with
water warmed to 45 – 35°C.
The efficiency criterion for adsorptive heat pumps is coefficient of energy
performance COP. СОР is calculated by two methods:
1)
as ratio of adsorption heat to sum of desorption heat and external heat supplied
to adsorbent during its heating upto regeneration temperature (СОР
c
);
2)
as ratio of adsorption heat to heat supplied by solar collector (СОР
s
(b)) (net).
Results of calculation are given in Table 1.
Table 1 Adsorptive heat pump coefficient of energy performance
Month
The total average daily value of solar
radiation (kW-h/m
2
)
‘silica gel – Na
2
SO
4
’
СОР
c
СОР
s
(b)
May
5.99
2.084
1.130
June
5.86
2.084
1.133
July
6.06
2.084
1.128
August
5.66
2.084
1.137
September
4.41
2.084
1.176
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