A water-cooled condenser in a large refrigeration system uses R-134a as its refrigerant fluid. The refrigerant enters the condenser at 1.0 MPa and 60 deg C, at a rate of 0.2 kg/s, and exits as a liquid at 0.95 MPa and 35 deg C. Cooling water enters the condenser at 10 degC and exits at 20 degC.

Create a schematic representation of the condenser and draw the boundary of the system needed to answer the next questions. Include the mass and energy interactions across the boundary.

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.

What is the major difference between thermoplastics and thermosetting plastics from the polymerization structure point of view?

Consider airflow over a flat plate of length l = 1.5 m under conditions for which transition occurs at le = 0.9 m based on the critical reynolds number, re,e = 5 x 10. evaluating the thermophysical properties of air at 400 k, determine the air velocity. (hint: use the tables to find the properties of air)