PAGLIPAT NG INIT

At an average temperature/of 100°C, hot air fiows through a 2.5 m long tube with an inside diameter of 50 mm. The temperature of the tube is 20°C along Its entire length. Convective film coefficient is 20.1 W/m2-K Determine the convective heat transfer from air to the tube.

Steam, initially saturated at 2..05 MPa, passes through a 10.10 cm standard steel pipe for a total distance of 152m. The steam line is insulated with 5.08 cm thickness of 85% magnesia. For an ambient temperature of 22C, what is the quality of the steam which arises at its destination if the mass flow rate is 0.125 kg steam per second? Properties of steam: Pressure: 2.05 mpa. temperature: 213.67C hf=914.52 hfg=1885.5kj/kg hg=2800kj/kg. Note: k= 85% magnesia is 0.069W/m-k and ho for still air is 9.36 w/m2-k

The sun generates 1 kW/m when used as a source for solar collectors. A Collector with an area of 1 m* heat water. The flow rate is 3.0 liters per minute. What is the temperature rise.in the water? The spècífic heat of water Is 4,200 J/kgC

The hot combustion gases of a furnace are separated from the ambient air and surrounding which are al 25°C, by a brick wall 0.15 m thick. The brick has a thermal conductivity of 1.2 W/m-K and a surface emissivity of 0.80. Under steady state conditions and outer surface temperature o f 100C, ls measured. Free convection heat surface temperature of 100C is measured. Free convection heat transfer to the air adjoining this surface is characterized by a convection coefficient of 20 W/m2-K. What is the inner temperature in "C?

A 6 in. x 20 ft uninsulated B.I. Pipe conveys steam at 385°F with an average ambient temperature of 85F. IF the cost of the fuel is P 250.00 per 10 B with the net energy conversion efficiency of 75%, what is the annual cost of the heat lost?

What is the external heating surface area in square feet of a tube with the following dimensions: tube inside diameter 5 in. Wall thickness % in: length 18 ft.

Determine the vacuum efficiency of a surface condenser which operates at a vacuum of 635 mm Hg and exhaust stéam enters the condenser at 45.81C. The barometric pressure is 760 mmHg and the saturation pressure at 45,81°C s 0.010 Mpa

A heat exchanger was installed purposely to cool 0.50 kg of gas per second. Molecular weight is 28 and k = 1.32. The gas Is cooled from 150°C to 80°C. Water is availlable at the rate of 0.30 kg/s and at a temperature of 12°C. Calculate the exit temperature of the water?

An uninsulated steam pipe passes through a room in which the air and walls an at 3t The cutside diemeter of the pipe is 70 mm, and S SUTaCe temperature and emissivity are 200C and 0.8 respectively. If the coemiaent asSociate with free convection heat transfer from the surface to he air s 15 W/m what is the rate of heat loss from the surface per unit length of pipe?

Heat exchanger Is to be designed for the following specification: Hot gas temperature= 1145°C Cold gas temperature =45°C Unit surface conductance on the hot side =230w/m2-k Unit surface conductance on the cold side =290/m2-k Thermal Conductivity of the metal wall=115/m2-k Find the maximum thikness of the metal wall between the hot gas and cold gas so that the maximum temperature of the wall does not exceed 545°C.

Calculate the heat transfer per hour through a solid brick wall 6 m long, 2.9 m high, and 225 mm thidk, when the outer surface is at 5C and the inner surface 17C, the coefficient of thermal conductivity of the brick being 0.6 W/m-K.

A vertical furnace wall is made up of inner wall of firebrick 20 cm thick followed by insulating brick 15 cm thick and an outer wall of steel 1 cm thick. The surface temperature of the wall adjacent to the combustion chamber is 1200 C while that of the outer surface of steel is 50 C. The thermal conduc.... Of the wall material in W/m-k are: firebrick 10; insulating brick, 0.25 and steel .45 neglecting the film resistances and contact resistance of .... Determine the heat loss per sq. M of wall area.

A composite wall is made up of an external thickness of brickwork 110 mm thick inside which is a layer of fiberglass 75mm thick. The fiberglass is faced internally by.......

One insulated wall of a cold-storage compartment is 8m long by 2.5 m high and consists of an outer steel plate 18 mm thick An inner wood wal 22.5 m thick, the steel and wood are 90 mm apart to form cavity which is filled with cork. If the temperature drop across the extreme faces of the composite wall 15°C. Calculate the heat transfer per hour through the wall and the temperature drop across the thickness of the cork. Take the coefficients of thermal conductivity for steel, cork and wood as 45, .045, and 0.18 Wim-K respectively

A cubical tank of 2 m sides is constructed of metal plate 12 mm and contains water at 75C. The surrounding air temperature is 16°C. Calculate the over all heat transfer coefficient from water to air. Take the coefficient of thermal conductivity of the metal as 48 W/m-K, the coefficient of thermal conductivity of the metal as 48 W/m-K, the coefficient of heat transfer of water is 2.5 kW/m-K A coefficient of heat transfer of the air is 16 W/m-K.

Calculate the quantity of -heat conducted per minute through a duralumin circular disc 127 mm diameter and 19 mm thick when the temperature drop across the thickness of the plate ls 5°C. Take the coefficient of thermal conductivity of duralumin as 150 W/m-K.

A Cold storage compartment is 4.5 m long by 4 m wlde by 2.5 m high, Th wals, celbng and loor are covered to a thickness of 150 mm with insu matenel which has a coeficient of thermal conductivity of 5.8 x 102 wn Cakulete the quantty of heat leaking through the insulation per hour whe otcside and inside face temperatures of the materlal is 15°C and respectvely

A thin square steel plate, 10 am on a side, is heated in a blacksmiths forge to a temperature of 800C . If the emissivity radiation of energy is 0.60, what is the total rate of energy?

A furnace wall consist of 35 cm firebrick (k=1.557W/m-k), 12 cm insulating (k = 0.346) and 20 m common brick (k=0.692) covered with 7 cm steel p[late k=45. The temperature at the inner surface of the firebrick is 1230 C and the outer face of the steel plate is 60 c. Atmosphere 27 . What is the value the combined coefficient for convection and radiation from the outside wall?

A dry ice storage chest is a wooden box lined with glass fiber insulation 5 am thick. The wooden box (k = 0.069) is 2 am,thick and cubical 60 cm on an edge. The inside surface temperature is-76 C and he outsde surtace temperature is 18°C. Use k 0.035 for glass fiber insulation. Determine the heat gain per day.

One side of refrigerated cold chamber is 6 m long by 3.7 m high and consists of 168 mm thickness of cork between outer and inner walls of wood, The outer wood wall s 30 mm thick and its outside face temperature is 20°, the inner wood wall is 35 nm thick and its inside face temperature is-3°C. Taking the coefficient of thermal conductivity of cork and wood as 0.042 and 0.20 W/m respectively, calculate the heat transfer per second per sq. M of surface area.

Hot gases at 280°C flow on one side of a metal plate of 5Omm thickness and air at 35°C. Flows on the other side. The heat transfer coefficient of the gases s 31.5 W/m-K and that of the air is 32 Wm-K. Calculate the over-all transfer coefficient if the value of thermal conductivity is(0. 01)

The surface temperature of the hot side of the furnace walls 1200°C. It iss desired to maintain the outside of the wall at 38°C.A 152 mm of reractory Sillca Is used adjacent to the combustion chamber and 10 mm of steel covers the outslde. What thickness of insulating bricks is necessary between refractorY and steel, If the heat loss should be kept at 788 W/m' ? Use k 13.84 W/m-K for refractory silica; 0.15 for insulating brick, and 45 for steel.

How much heat will flow in 24 hours through a plaster wall that is 0.50 In th and 8 ft x 14 ft in area if the temperature is 80°F on one side and 40°F on th other. Use k = 3.25 Btu-in/hr-ft-°F.

A hollow sphere has an outside radius of 1 m and is made of polystyrene foam with a thidness of 1 am. A heat source inside keeps the inner surface 5.20- hotter than the outside surface. How much power is produced by the heat source? The themal conductivity of polystyrene foam Is 0.033 W/m°C.

A glass window has an area of 1.60 m and a thickness of 4 mm. If one side is at a temperature of 6.80°C and the other is at -5°C, how much thermal energy flows through the window in a time of 24 hours? The thermal conductivity of glass is 1.99x10^-4 kCal/m-s-C