4) A horizontal pipe 6 m long and 12.5 cm in diameter is maintained at a temperature of 150-C in a large room where the air is 20-C and 1 atm. The walls of the room are at 38°C. Assume that €=0.7 for the pipe. How much heat is lost by the pipe through both convection and radiation? 1:44 PM

3.4 Estimate the rate of heat loss due to radiation from a covered pot of water at 95 ° C. How does this compare with the 60 W that is lost due only to convection and conduction losses? What amount of energy input would be needed to maintain the water at its boiling point for 30 minutes? The polished stainless steel pot is cylindrical, 20 cm in diameter and 14 cm high, with a tight-fitting flat cover. The air temperature in the kitchen is about 25 ° C. State any assumptions you make in deriving your estimates

1) A wall section composed from the outside to inside, of concrete brick 100mm thick, an air space of 50mm, two layers of fiberglass insulation 38mm thick, concrete block 150mm thick and air space of 19mm and a gypsum board of 13mm. The exterior conditions are -20C and RH=90% while the interior conditions are 23C and RH=40%. The surface temperature from the outside to inside are shown in the figure. The permeances are: Still Air: µ = 175 ng/pa.s.m Fiber glass: M=2560 ng/pa.s.m? Concrete block: M= 200 ng/pa.s.m? Gypsum board: M= 2000 ng/pa.s.m? Concrete brick: µ = 4.55 ng/pa.s.m Determine if there is a risk of condensation, and if there is, what is the condensation rate? What would happen if a vapor barrier (M=0.2 ng/pa.s.m²) was installed on the warm side of the insulation (Surface 4). 21с 19C 16 С 12C -10 -15C -18C -19C Gyp Air Concrete Fiber Fiber Air Concrete Outdoor Indoor sum block Glass Glass brick 230 19 50 mm -20C 13 150 mm 38 mm | 38 mm 100 mm RH=90% RH=40% mm mm Surf. 1 Surf.…

The diagram below illustrates a simplified version of the Jet Propulsion Laboratory's 25-ft space simulator chamber. Within it, tests are run for deep space probes and their components. In this particular experiment, a sensor assembly with its housing is placed inside. The sensor-housing electronics create heat such that q=3181.0 W exits the assembly's top surface into the chamber. The chamber itself is under vacuum, and its walls are at cryogenic temperatures to simulate conditions in space. Surfaces 1 and 2 are flat. Assume they are flush. The top surface of the chamber, Surface 4, can be approximated as a perfectly insulated, flat ceiling. The exposed surface of the floor, Surface 2, is a black, donut- shaped surface. Additional surface information can be seen below, including various parameters and dimensions. Assume all surfaces are opaque and diffuse, and conditions are at steady-state. PARAMETERS & DIMENSIONS Surface 1: A = 7.07 m²; diameter d; = 3 m; &₁ = 0.5; Surface 2: A₂ =…

A wall receives sunlight from 7:30 am to 6:30 pm. The amount of energy it receives is 420 W/m2 and 15% is emitted as radiation into the surrounding air. The inside of the wall has a temperature of 48°C. If the wall is 7 m long and 6 m high and 30 cm thick, what is the temperature when x=20 cm?

4 ft 2 ft A 7 ft tall steel cylinder has a cross sectional area of 15 ft². At the bottom with a height of 2 ft is liquid water on top of which is a 4 ft high layer of gasoline. The gasoline surface is exposed to atmospheric air a 14.7 psia. What is the highest pressure in the water? Air Gasoline Water