Experimental investigation of a heat pump assisted drum drying systems using propane (R290) as working fluid - Eksperimentelle undersøkelser av en varmepumpeassistert tørketrommel

Abstract

Dryer is a wide spread machine for drying cloth in family. The traditional heat pump dryer use R134a as working fluid. But this working fluid do not meet the standard in aspect of global warming. R290 is a very good green natural refrigerants. It has no damage to the environment as its ODP = 0 and GWP= 3.3. So we want to use R290 to replace R134a in the heat pump dryer. To compare the performance, we use some parameter like COP, SMER and the energy cost. There are heat pump cycle and dryer cycle in the system. The working fluid goes through the compressor to rise the temperature and pressure, then it pass the condenser to rise the temperature of the air. Then it goes through a throttling process to a comparably low temperature to cool the air in the evaporator and go back to the compressor. The air is heated in the condenser then rise a little temperature through a fan. In the drum the air takes a lot of heat and water away, and the vapor condensed in the evaporator. Then it go back to the condenser to be heated again. The system was tested for three times, measuring the temperature in the dryer cycle, the air flow, the temperature and humidity in the dry cycle and the water get out of the system. The result is analyzed and some problems are found and get some guesses. Further experiment will insert pressure measurement to get the exact point on T-s and P-h diagram.