Question

describe two appliances based on concept of vaporization and latent heat of vaporization

Answer 1

Refrigerators , Heat Exchangers 

Answer 2

1) Vapour steam cleaners- This appliance use steam to dry, clean and sanitise surfaces. The steam's ability to clean is based on its heat. No chemicals are used in this cleaning process so it is also called green cleaning.
2) Heat exchangers- It works via condensation of warmer fluid on to a pipe which contains fluid at low temperature, effectively transferring the heat of vaporisation. Shell and tube heat exchangers are installed on the exhaust steam from a steam turbine in thermal power stations.