ISSN Online: 2377-424X
International Heat Transfer Conference 12
A Study on Heat and Mass Transfer for Air/Water Direct-Contact Air Conditioning System
摘要
Direct-contact air conditioning system, in which
heat and mass are transferred directly between air and
water droplets, has many advantages over the
conventional indirect contact system. The purpose of
this research is to investigate heat and mass transfer
characteristics of direct-contact air conditioning system
for various inlet parameters such as air velocity, air
temperature, water flow rate and water temperature.
Experimental apparatus comprises wind tunnel, water
spray system, scrubber, demister, heater, refrigerator,
flow and temperature controller, and data acquisition
system. Inlet air is controlled by constant temperature
bath, inlet water is controlled by electric heater and
vapor compression refrigerator, and flow rate of air
and water is controlled by inverter. Inlet and outlet
conditions of air and water are measured when the air
contacts directly with water droplets as a counter flow
in the spray section of the wind tunnel, and heat and
mass transfer rate between air and water are calculated.
Droplet size of water spray is also measured using
Malvern Particle Analyzer. In the cooling conditions,
the outlet air temperature and humidity ratio decrease
as the water flow rate increases and as the water
temperature, air velocity and temperature decrease. On
the contrary, the outlet air temperature and humidity
ratio increase in the heating conditions as the water
flow rate and temperature increase and as the air
velocity decreases.