Composite window, LA = 2LB Lop Oven cavity To T250 °C T = 400 °C h = 25 W/m2K Air B, kg = 0.08 W/m-K A, ka = 0.15 W/m-K
Posted: Sun May 15, 2022 9:48 pm
- Composite Window La 2lb Lop Oven Cavity To T250 C T 400 C H 25 W M2k Air B Kg 0 08 W M K A Ka 0 15 W M K 1 (54.6 KiB) Viewed 33 times
- Composite Window La 2lb Lop Oven Cavity To T250 C T 400 C H 25 W M2k Air B Kg 0 08 W M K A Ka 0 15 W M K 2 (50.06 KiB) Viewed 33 times
a) A leading manufacturer of household appliances is proposing a self-cleaning oven design that involves use of a composite window separating the oven cavity from the room air (Figure 2a). The composite is to consist of two high-temperature plastics (A and B) of thicknesses La = 2L8 and thermal conductivities ka=0.15 W/m-K and kB 0.08 W/m.K. During the self-cleaning process, the oven wall and air temperatures, Tw and T., are 400°C, while the room air temperature T. is 25°C. The inside convection and radiation heat transfer coefficients h, and h,, as well as the outside convection coefficient ho, are each approximately 25 W/m².K. What is the minimum window thickness, L = LA + LB, needed to ensure a temperature that is 50°C or less at the outer surface of the window? This temperature must not be exceeded for safety reasons. (15 marks)