A client has an airstream that is 150 ºC and at 1 atm of pressure that contains 50,000 ppm of heptane. To what temperature must air be cooled to remove 40% of its heptane vapor content?

A heat pump is required for a single-family 2-story, 3-person, 30 ft x 30 ft x 18 ft (L x W x H), energy- efficient residential house in Philadelphia, PA, for a typical winter season. Assuming a comfortable indoor temperature is 70 °F and on a cold winter day the outdoor temperature is 10 °F. Exercise #1: Calculate total heat loss from a house in Philadelphia on a cold winter day. Assume 40% of the wall area is windows with U-value of 0.81 BTU/hr-ft²-°F. The remaining 60% of the walls has a U-value of 0.2 BTU/hr-ft²-°F. The roof has a U value of 0.05 BTU/hr-ft?-°F and the floor U-value is 0.41 BTU/hr-ft²-°F. For simplicity assume that the ground temperature is the same as the air temperature. [However, in your project design calculations you should refine this assumption.] Assume 0.5 air changes per hour (ACH) due to natural ventilation, such as leakage through windows, etc. Neglect any radiative heat loss/grain from the house. Exercise #2: Determine the watts of electricity needed by…

Forced air at T = 25°C and V = 10 m/s is used to cool electronic elements on a circuit board. One such ele- ment is a chip, 4 mm X 4 mm, located 120 mm from the leading edge of the board. Experiments have revealed that flow over the board is disturbed by the elements and that convection heat transfer is correlated by an expression of the form Nu,= 0.04 Re0.85 P.1/3 V. T uz bog fr dW ninin tol 1 = 4 mm Chip Board 0:00 Wira L= 120 mm Estimate the surface temperature of the chip if it is dis- sipating 30 mW.

2 A wire of diameter D = 2 mm and uniform temperature T has an electrical resistance of 0.01 N/m and a current flow of 20 A. (a) What is the rate at which heat is dissipated per unit length of wire? What is the heat dissipation per unit volume within the wire? (b) If the wire is not insulated and is in ambient air and large surroundings for which T = Tsur = 20°C, what is the temperature T of the wire? The wire has an emissivity of 0.3, and the coefficient associated with heat transfer by natural convection may be approximated by an expression of the form, h = C[(T-T)/D]¹/4, where C = 1.25 W/m7/4.K5/4 (c) If the wire is coated with plastic insulation of 2-mm thickness and a thermal conductivity of 0.25 W/m.K, what are the inner and outer surface temperatures of the insulation? The insulation has an emissivity of 0.9, and the convection coefficient is given by the expression of part (b). Explore the effect of the insu- lation thickness on the surface temperatures. Note: 1. The metal wire…

the pressure drop across the tube bank, and (c) the rate of condensation of steam inside the tubes. Evaluate the air properties at an assumed mean temperature of 35°C and 1 atm. Is this a good assumption?solve this part too

1. Liquid oxygen is stored in a spherical tank with D = 5 ft. The surface of the tank was isolated with insulation material A with a thickness of 8 in and outside with material B with a thickness of 0.5 ft (kA = 0.022 Btu / j.ft.oF and kB = 0.04 Btu / j.ft.oF). Tank surface temperature (–4) oC and insulation surface temperature 50oC Calculate heat transfer from air to liquid oxygen tank! 2. A 2.0 inch Schedule 40 pipe has k = 27 Btu / h.ft.oF. The fluid in the pipe has h = 30 Btu / h.ft2.oF. The outer surface of the pipe is coated with a fiber glass insulation thickness of 4 mm with k = 0.023 Btu / h.ft.oF. The convection coefficient on the outer surface of the insulation is 2.0 Btu / h.ft2.oF. The temperature of the fluid contained in the pipe is 320oF and the ambient temperature is 70oF. Calculate the heat loss per unit length of pipe! 3. Two parallel plates with a diameter of 60 cm, separated at a distance of 15 cm. The temperature on the top surface is 4 oC and the temperature on…

4. The right figure shows a simple combustion calorimeter. The sample is ignited electrically. After a few minutes the temperature of the water and calorimeter is constant at AT higher than the starting temperature. Determine the heat of combustion of a sample from the following data: Sample mass Calorimeter mass Water mass 4 g 500 g 5000 g The heat of combustion is defined as = Sample Inlet 0 75 400 Temperature °F 70.0 Cvcalorimeter Cywater Ufinal products of combustion Pressure, psig Elevation, ft Velocity, ft/s AT Stirrer Uinitial fuel+oxygen Au combustion msample 5. A steady-flow water power plant has the following inlet and outlet conditions: Oxygen Outet 0 0 50 70.1 Water Thermometer Heavy steel bomb 0.12 cal/g °C 1.0 cal/g °C 5 °C

On a day when wind is blowing over a lake (T(water) =20°C) at 5 m/s, which side of the air-water interface will be rate-limiting on the flux of Ethyl benzene (i.e. va or vw)?