Test: Psychrometric Chart & Its Application to Air-Conditioning - 1 - Mechanical Engineering MCQ

Process 1 —> 2, adiabatic mixing

1→2 : Chemical dehumidication so, DBT increases

On psychrometric chart, constant WBT fines coincide with constant enthalpy lines.

Where
t_d1 = dry bulb temperature of air entering to the coil
t_d2 = dry bulb temperature of air living the coil
t_d3 = dry bulb temperature of coil

Cooling and dehumidification : The dehumidification of air is only possible when the effective surface temperature of the cooling coil is less than the dew point temperature of the air entering the coil.

Pure dehumidification is achieved by passing air through the spray water which is maintained at dew point temperature. By doing this, excess moisture condenses and temperature remains constant.

During the adiabatic saturation process, the partial pressure of vapour increases, although the total pressure of the air-vapour mixture remains constant.
It may be noted that the adiabatic saturation temperature is taken equal to the WBT for practical purposes.