Page 157 - Low Temperature Energy Systems with Applications of Renewable Energy

Heat pumps in the drying industry 147

Fig. 4.14 COP for different types of HP system: barley drying with air at 66 C and 4 ¼ 5%.
Table 4.2 Energy consumption when drying textiles.
Driers with oil combustion
Oil consumption, MJ/h 599
Power consumption, kW 2.29
Drying time, h 5.75
Amount of moisture removed, kg 154
Specific energy consumption (SEC), MJ/kg 22.4
SEC, accounting for the efficiency of energy generation, MJ/kg 31.7
Heat pump dryer with electric drive
Nominal electric power, kW 15
Average power consumed, kW 18.4
Drying time, h 5.75
Amount of moisture removed, kg 154
SEC, MJ/kg 2.02
SEC, accounting for the efficiency of energy generation, MJ/kg 7.7
Comparison
Reduction in SEC, % 91
Reduction in SEC, accounting for the efficiency of energy generation,% 76
Reduced operating costs,% 70
Payback period, years 2.4