Water is boiling in a 25 cm diameter aluminum pan (k=237 W/mK) at 95 degrees C. Heat is transferred steadily to the boiling water in the pan through its .5 cm thick flat bottom at a rate of 800 W. if the inner surface temp of the bottom of the pan is 108 degrees C determine the boiling heat transfer coefficent on the inner surface of the pan and the outer surface temp of the bottom of the pan.

Water is boiling in a 25 cm diameter aluminum pan (k=237 W/mK) at 95 degrees C. Heat is transferred steadily to the boiling water in the pan through its .5 cm thick flat bottom at a rate of 800 W. if the inner surface temp of the bottom of the pan is 108 degrees C determine the boiling heat transfer coefficent on the inner surface of the pan and the outer surface temp of the bottom of the pan.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter7: Forced Convection Inside Tubes And Ducts

Section: Chapter Questions

Problem 7.25P

See similar textbooks

Similar questions

Example 7 A cooking pan whose inner diameter is 20 cm is filled with water and covered with a 4-kg lid. If the local atmospheric pressure is 101 kPa, determine the temperature at which the water starts boiling when it is heated. Answer: 100.2°C Patm = 101 kPa mlid = 4 kg H,0
Water in a tank is to be boiled at 143.27 Pa absolute pressure by a 1.5-cm-diameter brass heating element equipped with electrical resistance wires inside, as shown in the figure. Determine the maximum heat flux that can be attained in the nucleate boiling regime and the surface temperature of the heater in that case. (3.23x105 W/m2, 118.6°C)
Faster please
In boiling water at 1 atm pressure outside a stainless-steel tube with a surface temperature of 410F, the heat-transfer coefficient h in the absence of radiation is 32 Btu/h*ft^2*F. If the emissivity of the stainless steel is 0.8, will radiation significantly augment the rate of boiling (e.g., by more than 5 percent)? Assume that the vapor film is transparent to radiation and the boiling liquid is opaque.
The boiling temp of nitrogen at 1 atm is -196°C. If the temperature of liquid nitrogen in a tank open to the atmosphere at sea level will remain constant until it is depleted, then any heat transfer to the tank will result in the evaporation of some liquid nitrogen, which has a heat of vaporization of 198 kJ/kg and a density of 810 kg/m³ at 1 atm. Consider a 3.5-m-diameter spherical tank that is initially filled with liquid nitrogen at 1 atm and -196°C. The tank is exposed to ambient air at 16°C, with a convection heat transfer coefficient of 32 W/m2- °C. The temperature of the thin-shelled spherical tank is observed to be N2 vapor almost the same as the temperature of the nitrogen inside. Determine the rate of evaporation of the liquid nitrogen in the tank (in kg/s) as a result of I atm Liquid N3 -196°C heat transfer from the ambient air if the tank is (a) not insulated, (b) insulated with 6-cm thick fiberglass insulation (k=0.035 W/m-°C) and (c) insulated with 2-cm thick…
In an aluminum pot, 0.796 kg of water at 100 °C boils away in four minutes. The bottom of the pot is 1.03 × 10-3 m thick and has a surface area of 0.0294 m². To prevent the water from boiling too rapidly, a stainless steel plate has been placed between the pot and the heating element. The plate is 2.67 x 10-3 m thick, and its area matches that of the pot. Assuming that heat is conducted into the water only through the bottom of the pot, find the temperature in degrees Celsius at the steel surface in contact with the heating element. Number i Units
A cylindrical pan containing water is placed on top of a heating unit. The pan is teflon-pitted stainless steel and it has 20-cm-internal diameter. Water is boiled at 198.53 kPa pressure. It is found that the water level in the pan drops by 20 cm in 30 min after it starts to boil, determine a) the heat flux (kW/m?) to the water and (b) the inner surface temperature (°C) of the pan Hint: Assume nucleate boiling. Select the closest value to your answer. a) the heat flux (kW/m²) to the water Choose... + (b) the inner Surface temperature (°C) of the pan Choose... +
The condenser of a steam power plant operates at a pressure of 7.38 kPa (Tsat = 40°C). Steam at this pressure condenses on the outer surfaces of horizontal pipes through which cooling water circulates. The outer diameter of the pipes is 3 cm, and the outer surfaces of the pipes are maintained at 30°C. Determine the rate of condensation of steam per unit length of a horizontal pipe. The properties of water at the saturation temperature of 40°C are: hfg = 2407 × 10^3J/kg and ρv=0.05 kg/m3. The properties of liquid water at the film temperature: ρl = 994 kg/m3, Cpl =4178 J/kg°C, µl = 0.72 × 10^-3 kg/m.s, kl = 0.623 W/m°C Select one: a. 0.0026 kg/s b. 0.0046 kg/s c. 0.0016 kg/s d. 0.0036 kg/s
Saturated steam at 1 atm condenses on a 3-m-high and 5-m-wide vertical plate that is maintained at 90 0C by circulating cooling water through the other side. Determined (a) the rate of heat transfer by condensation to the plate, and (b) the rate at which the condensate drips off the plate at the bottom (Please use the condensation formulations at the Geankoplis).
A long 3-mm diameter rod of steel (ρ = 7840 kg/m3, c = 460 J/kgK, k = 43 W/mK)has a uniform initial temperature of 650C. The rod is then suddenly immersed in alarge container of 25C water. The hot rod causes the water immediately surroundingthe rod to boil, giving rise to a heat transfer coefficient of 5600 W/m2K. The boilingstops when the rod reaches a temperature of 100C, at which time the heat transfercoefficient becomes 750 W/m2K. Find the time period during which boiling occursand the total time required for the rod to reach a temperature of 40C. Use acharacteristic length for this problem.
The boiling temperature of oxygen at atmospheric pressure at sea level (1 atm) is -183ºC. Therefore, oxygen is used in low temperature scientific studies since the temperature of liquid oxygen in a tank open to the atmosphere remains constant at -183ºC until the liquid oxygen in the tank is depleted. Any heat transfer to the tank results in the evaporation of some liquid oxygen, which has a heat of vaporization of 213 kJ/kg and a density of 1140 kg/m3at 1 atm. Consider a 4 m diameter spherical tank initially filled with liquid oxygen at 1 atm and -183ºC. The tank is exosed to 20ºC ambient ait with a heat transfer coefficient of 25 W/m2. ºC. The temperature of the thin-shelled spherical tank is observed to be almost the same as the temperature of the oxygen inside. Disregarding any radiation heat exchange, determine the rate of evaporation of the liquid oxygen in the tank as a result of the heat transfer from the ambient air
Water is boiled at 250°F by a 2-ft-long and 0.5-in diameter nickel-plated electric heating element maintained at 280°F. Determine (a) the boiling heat transfer coefficient, (b) the electric power consumed by the heating element, and (c) the rate of evaporation of water.