P2.6 A clear plastic window of a building has a thickness of 22 mm and a thermal conductivity of 0.17 Wm K. It absorbs solar radiation at a uniform rate of 20 kWm³ throughout the material. The outside and inside heat transfer coefficients are 25 Wm ²K¹ and 8 Wm ²K¹ respectively. The outside and inside ambient temperatures are 25°C and 15°C respectively. Calculate (i) the inside and outside wall surface temperatures, and (ii) the rate of heat flow into the room. [Answers: (i) 38.8°C, 35°C, (ii) 190.4 Wm ²]

1.3 A furnace wall is to be constructed of brick having standard dimensions of Two kinds of material are available. One has a maximum usable temperature of 1040°C and a thermal conductivity of 1.7 W/(m K), and the other has a maximum temperature limit of 870°C and a thermal conductivity of 0.85 W/(m K). The bricks have the same cost and are laid in any manner, but we wish to design the most economical wall for a furnace with a temperature of 1040°C on the hot side and 200°C on the cold side. If the maximum amount of heat transfer permissible is 950 , determine the most economical arrangement using the available bricks.

A house, for cooling purposes, consists of two zones: the attic area zone A and the living area zone B (see below figure). The living area is cooled by a 2-ton air conditioning unit that removes °F per thousand Btu. The time constant for heat 19 4 41,000 Btu/hr. The heat capacity of zone B is transfer between zone A and the outside is 2 hr, between zone B and the outside is 4 hr, and between the two zones is 4 hr. If the outside temperature stays at 90°F, how warm does it eventually get in the attic zone A? It eventually gets to be F in the attic zone A. (Type an integer or decimal rounded to the nearest hundredth as needed.) 4 hr 쉽 A H 4 hr B 2 hr MIN 41,000 Btu/hr

Consider a copper plate that has dimensions of 3 cm x 3 cm x 7 cm (length, width, and thickness, respectively). As shown in the following figure, the copper plate is exposed to a thermal energy source that puts out 126 J every second. The density of copper is 8,900 kg/m³. Assume there is no heat loss to the surrounding block. 126 J Copper Insulation Ⓡ What is the specific heat of copper (in J/(kg K))? J/(kg. K) What is the mass of the copper plate (in kg)? kg How much energy (in J) will be consumed during 11 seconds? J Determine the temperature rise (in K) in the plate after 11 seconds.

Q2) The outer surfaces of the plane composite wall (A, B and C) are exposed to a fluid at 25'C and a convection heat transfer coefficient of 1000 W/m² "C. The thickness of walls A, B and C are 30, 60 and 20 mm, respectively. The thermal conductivity of walls material A, B and C are 25, 15 and 50 W/m "C, respectively. The middle wall (B) has a uniform heat generation, while there is no generation in walls A and C. The outer surfaces temperature of A and C are 132°C and 158°C, respectively. At steady state-one dimensional heat transfer conditions calculate: (1) The temperature in wall B at a distance of 10 mm from interphase of walls B and C. (2) The temperature in wall B at a distance of 5 mm from interphase of walls B and A. (3) The temperature at the middle of wall B.

A house, for cooling purposes, consists of two zones: the attic area zone A and the living area zone B (see below figure). The living area is cooled by a 2-ton air conditioning unit that removes 19 °F per thousand Btu. The time constant for heat 4 41,000 Btu/hr. The heat capacity of zone B is transfer between zone A and the outside is 2 hr, between zone B and the outside is 4 hr, and between the two zones is 4 hr. If the outside temperature stays at 90°F, how warm does it eventually get in the attic zone A? It eventually gets to be F in the attic zone A. (Type an integer or decimal rounded to the nearest hundredth as needed.) 4 hr Î A 쉽 4 hr B 2 hr 41,000 Btu/hr

An AISI stainless steel spherical canister is bath-cooled to store chemicals. The properties of the canister and chemicals are illustrated in the figure below. The inner wall heat flux is qi" = 10 kW/m2.  a) Determine the initial rate of change of the canister temperature at the outer wall b) Determine the steady-state inner and outer wall temperatures

Q2/ A (2 cm) thick steel plate of thermal conductivity (50 W/m.°C) has a uniform heat generation of (40 x 106 W/m³). The temperature at the left surface of the plate is (160 °C) and at the right surface is (100 °C) start from principle to find the place and the value of the maximum temperature. (25 marks)

A hot water pipe is 100 mm in diameter and 80 m long. This pipe is insulated in two layers. First layer is 25 mm thick, thermal conductivity is 0.12 W/m C material, second layer is 45 mm thick It is made of material with a thermal conductivity of 0.05 W/m C. T1, T2 and T3 are the surface temperatures in the pipe. One With the acceptance of heat transfer in dimensional and continuous conditions, transfer from the pipe in case T1= 600 OC and T3= 35 C Find the amount of heat released and the temperature T2. 2.tabaka 1.tabaka 100 mm T₁ T₂ T3

A 1000 m³ cubic building (meaning it is a cube with sides of length 10.0 m) has concrete walls 20 cm thick. Concrete has a thermal conductivity of 1.25 W/(mK). An indoor temperature of 21 C is maintained. If it is -15 C outside determine the rate of heat loss from the building. Answer: Check ✓ Choose... W J