In class XI, we were taught thermodynamics and I came across Carnot engine. Sadi Carnot devised this engine in 1824 which is several years before the laws of thermodynamics were formally laid down. Theoretically Carnot engine can achieve efficiency of 1 which is highest possible efficiency. My curiosity was touched and I made up my mind to build a Carnot engine. Although I didn’t made any success in this direction, my quest of finding an efficient heat engine started from this time. This is when my admiration for a pressure cooker reached new heights and it became my favourite appliance.
The pressure cooker is a heat engine. While it has been across my sight since childhood, I was able to appreciate its working when I became aware of the principle behind it after reading thermodynamics. The basic principle behind the working of a pressure cooker is the variable of pressure and temperature. Water that is used for cooking food, boils at 100 Degree Celsius at normal atmospheric pressure. However, in a cooker, the pressure is above atmospheric pressure due to which the boiling point of water increases. Thus water boils at a higher temperature and more energy is transferred to the food being cooked. I found a very simple explanation of the working on YouTube in the following video by Seema Rodge.
What amazes me is the simplicity of principle behind this appliance which causes huge saving of energy at the individual as well as global scale. When the world is reeling under the wrath of climate change, we should pause and appreciate the usefulness of simple appliances such as pressure cooker in decreasing en energy consumption. Although Carnot engine remains a theoretical model, research should strive to achieve higher efficiency in heat engines too. People can be made aware and we can push greater adoption of such appliances which saves energy such as pressure cooker.
Since the day I came to know about the usefulness of Pressure cooker, I have always talked about it with my friends and elders. So that’s my favourite appliance. Please tell me about your favourite appliance in the comments section. Cheers.