Question

spring relief disk 3.(40 pt.) A pressure cooker cooks a lot faster than an ordinary pan by maintaining a higher pressure and temperature inside. The lid of a pressure cooker is well sealed, and steam can escape only through an opening in the middle of the lid. The pressure relief valve consists of a spring-loaded disk that is positioned over this opening. Consider that a certain portion of a pressure cooker is initially filled with water and put on top of a stove (State - 1). Heat is added just until the pressure relief valve opens (State 2). Heat continues to be added until all of the liquid disappears (State 3). Using the knowledge that you learned in the Thermodynamics I Course, analyze the operation of this pressure cooker thermodynamically i.e. find the intensive properties of water such as temperature, pressure and quality, mass of liquid water in the cooker, mass of water vapor that has passed through the pressure relief valve and time passed for various stages of its operation). Operation and design parameters of the pressure cooker include volume of the cooker, initial volume of water, heat input rate, surrounding pressure, disk diameter, mass of the disk, spring constant, the change in length of the spring, etc. Using resources (e.g. textbooks, reports, websites, etc.), give appropriate numerical values for the operation and design parameters of the pressure cooker and find the results for each stage. Show the processes on a T-v diagram. List any assumptions that you make. Comment on your results considering a practical application.

Answer 1

As a solutions A liquid boils boils when the vapour pressure of the gal escaping from the liquid in equal to the presure exerted on the liquid by its Aurounding (lvasour - Pexternal) Condequence, the boiling point can ho manipulated by encresing the external ProMAUTE In regular cooker, Water in exposed to noimal external presure (normal barometric pressure = 10lkoa) and boils at 100°c (3716). When the lid is not in its position or the valve is to uncovered the Pressure cooker work as a reguler Cooker. Hoewever, it the valve is covered there will be a chong in inner pressure of the chamber and the liquid - vapour equilibrium will be displeed. When the valve is covered, the condition of the system chonger because the vapour phase to the Chamber. Asa consequences of the added mass, the pressure point is restricted rainel and the equilibrium between

between phases is displaced to a higher temperature, resulting in a boiling tooint. neu TV diagram Saturakd mixto Donospber CP) saturated U quad Saturated vapour -vg-vy v malug)