What is the heat transfer coefficient inside the tubes of a solar collector in which the tubes are 10 mm in diameter and separated by a distance of 100 mm? The collector is 1.5 m wide and 3 m long and has total flow rate of water of 0.075kg/s. The water average temperature is 80°C. Assume you have 15 tubes. Hint:need find Nu by equation not graph?

Problem 6. ART TAT Consider the cylindrical pipe shown in the figure. Heat is being generated in the pipe wall at a rate of R in units of W/m³, and the thermal conductivity of the wall is k, the heat transfer coefficients at the inside and outside of the pipe are h; and ho, respectively. At a given location along the pipe axis, the temperature of the fluid flowing inside of the pipe is Ti and that at the outside is To i. ii. Find the expression for the temperature distribution in the pipe wall. Find the total heat transfer rate from the pipe to both fluids.

To cool hot oil, an engineer has suggested that the oil be pumped through a pipe submerged in a nearby lake. The pipe (external diameter = 15 cm) will be placed in the horizontal direction. The temperature of the outer surface of the pipe averages 125 ° C. The surrounding water temperature is assumed to be constant at 15 ° C. Pipe length 125 m. If it is assumed that there is no water movement. a. Determine the convective heat transfer coefficient of the outer pipe surface to the water. = Answer Watt / (m² ° C) b. Determine the heat transfer rate from the pipe to the water. = Answer kW

10.The layout of a wall and the heat transfer parameters are shown in the figure below. Find the internal temperature of the wall, T₁. (o= 5.67 x 10-8 W/m²K4 ) (Ans: 569.5K) T1 k=1.1 W/m.K Icond L=0.12m T2=373K x=0.7 grad Iconv Tsur Air Tex = 300K h = = 290K : 18 W/m².K