Heat Balancing Characteristics of a Domestic Pressure Cooker

The study of “Heat Balance” in a domestic pressure cooker is an important investigation for energy conservation. In the present study, experiments were conducted on a domestic pressure cooker to measure Input Heat, Utilized Heat and Heat Lost for different volumes of water filled in a pressure cooker. Experiments were conducted on 0.008m³(8litre) pressure cooker filled with water at 12.5%, 25%, 37.5% and 46.25% of its capacity, respectively 1.0kg, 2.0kg, 3.0kg and 3.7kg of water. Two approaches were adopted to determine an optimum condition of the pressure cooker. In first approach, the pressure cooker was insulated and the other in non-insulated. In both cases, cookers of similar capacity, make and design were used. Outer surface of the cooker was insulated with asbestosrope, clay and cow-dung bindings. Interesting results were arrived during the study that, there was not having much difference in heat input, heat utilization for insulated and non insulated cookers when the water level was only about 12.5% volume. In other cases the insulated cooker consumes more heat input than the non-insulated cooker. The reason was found that thermal mass capacity of the insulated cooker was more and stores heat energy. When the pressure cooker is filled with 46.25% of its volume by water, it utilizes a maximum of 30% of total heat supplied. On reducing the volume of water filled in the cooker, the heat loss increased and consumes more thermal energy.