EXPERIMENTAL-STUDY OF HEAT-TRANSFER CHARA CTERISTICS OF MAT-TYPE ADSORPTION HEAT-PUMP

A silica gel-tube module (ST-module) was provided as a heat exchanger for an adsorption heat pump (AHP). A multiple adsorbent-tube (MAT) typ e adsorber containing the ST-modules was proposed and applied to the A HP for the silica gel/water vapor system. Heat transfer characteristic s in the AHP with the MAT - type adsorber were studied on the basis of the results compared with those in the AHP with a packed bed type ads orber. Both the maximum temperature rise in the evaporator and the tim es required to reach the initial temperatures in the adsorption and de sorption processes for the AHP with the MAT-type adsorber were reduced to about one-tenth of those for the AHP with the packed bed type adso rber. In the evaporator of this AHP, cold heat below 280 K was obtaine d at the adsorption process. Based on pressure profiles of water vapor in the adsorption process, it was found that the pressure difference between the adsorber and the evaporator contributed to pumping-up of t he heat in the AHP. Therefore, enhancement of heat transfer in the ads orber of the AHP was achieved and the possibility of its application t o an airconditioner for producing cold heat energy was suggested.