The condenser of a steam power plant operates at a pressure of 12.35 kPa. Steam at this pressure condenses on the outer surfaces of horizontal tubes through which cooling water circulates. The outer diameter of pipes is 4 cm, and the outer surfaces of the tubes are maintained at 20°C (see the figure). Determine: The rate of heat transfer to the cooling water circulating in the tubes, and The rate of condensation of steam per unit length of a horizontal tub

Pure water flows through the cross section of the pipe 0.3m long and 3cm in diameter. The water entering the pipe has a flow rate of 373 K, 0.2 MPa to 2 kg/s. The discharged water also has a flow rate of 2 kg/s. At this time, the temperature is 373 K and the pressure is 0.195 MPa. Under this condition, the density of water is 961.5 kg/cm3. Find what was done at the entrance and exit of the pipe (J/s). Pay attention to the sign.

Heat Transfer Lesson The temperature will be increased from 10 (Degree Celsius oC) to 90 (Degree Celsius oC) while the water flows through a 1.5 cm inner diameter and 7 meter long straight pipe. Equipped with electric heater on the entire surface of the pipe. Even heating throughout. The outer surface of the heater is well insulated and therefore all heat generated in the heater in continuous operation is transferred to the water in the pipe. If the system provides a hot water flow rate of 6 liters / minute. (Thermophysical properties of water at 50 oC:ρ = 988 m3/kg, k= 0.6305 W/m oC, cp=4181 J/kg oC, Pr=3.628, μ= 0.0005471 kg/m.s ) a)Find the power of the resistance heater [W]. b)Calculate the inner surface temperature [oC] of the pipe at the outlet. c)Find the pressure drop [Pa]. d)Find the pump power [W] required to overcome this pressure drop.

The sensible heat-transfer coefficient for a dry surface has been determined to be 50 W/(m2-C) at a certain Reynolds number. Estimate the total heat transfer to the surface per unit area at a location where the wall temperature is 10 C and the state of the moist air flowing over the surface is given by 24 C dry bulb and 18 C wet bulb. Assume that the Reynolds number does not change and the Lewis number is 0.82. Assume that the condensate present on the surface will increase the transfer coefficients by about 15 percent.