APPLICATION OF THERMAL ENERGY TRANSFER

Friday, September 5, 2008

CONDUCTION
Using the conductors and insulators of heat, humans have invented many useful things, that are commonly used in our lifes.

Conductors of heat....
1.cooking utensils
2.soldering iron rods
3.heat exchangers

Insulators of heat.....
1.handles of appliances and untensils
2.table mats
3.sawdust
4.wooden ladles
5.woollen clothes
6.fibreglass, felt and expanded polystyrene foam

CONVECTION
Using convection, many daily electrical appliances are invented.

1.electrical kettles
--the heating coil of the kettle is placed at the bottom of the kettle to aid transfer of thermal energy in water using convection current. As heating of the water takes place, water that are near the heating coils heats up first, causing it to rise and cooler water sinks. And a convection current occurs...

2.Household hot water systems
--the water heated up by the bunsen burner, as hot water rises up, it is sent to tubes then to the sprinklers/taps..

3.air conditioners
--air conditioners are always installed near the ceiling of the a room to facilitate setting up of convection currents. as it gives out cool dry air into the room, and sinks, hot air rises and is drawn into the air conditioner to have it cooled, as air recirculates and the temperature of the air will eventually fall to the desired level.

4.refrigerator
--as the fridge keeps food cold and fresh it needs the help of an air conditioner, therefore its theory of using convection current is also the same as the air conditioners.

RADIATION
many things ae made useful in our daily lifes.

1. teapots
--as shiny surfaces are bad emmiters of radiation, shinny teapots can keep tea warm for a longer period of time as compared to dull coloured containers.

2.greenhouse
--it is useddin cold climate countries to help plants grow better by trapping heat. During the day infrared radiation from the sun is trapped in the greenhouse, warming up the soil and plants in the greenhouse. as contents in the greenhouse gets warm, they start to emit infrared radiation.

3.vacuum flask
--the sophisicated design of the thermal flask is used to keep liquid warm for a long period of time, with the aid of the theory of radiation.
Posted by xiaowei aunty at 5:11 AM