Page 156 - Low Temperature Energy Systems with Applications of Renewable Energy

146 Low-Temperature Energy Systems with Applications of Renewable Energy

Fig. 4.12 Overall efficiency of various drying systems. Note: For the two HPDs, the 80% and
90% refer to the moisture in the outlet air.

Throttles
Condenser

Compressor

High pressure Low pressure
vaporizer vaporizer

Condensate Condensate
Mixing
chamber
Air Cooling agent

Drying chamber
Fig. 4.13 Schematic diagram of a double-stage heat pump dryer.

for different heat pump drier arrangements are shown in Fig. 4.14. As can be seen, the
efficiency of heat pump drying systems can be increased by combining it with other
sources of heat, such as natural gas.
Heat pumps have significantly reduced energy consumption for drying textiles.
Data presented in Table 4.2 [26] compare the energy consumption during drying
with a heat pump and the original system where the heating of air is carried out by
burning oil.