Consider a Carnot cycle executed in a closed system with air as the working fluid. The maximum pressure in the cycle is 800 kPa while the maximum temperature is 750 K. If the entropy increase during the isothermal heat rejection process is 0.25 kJ/kg.K and the net work output is 100 kJ/kg, determine (a) the minimum pressure in the cycle,(b) the heat rejection from the cycle, and (c) the thermal efficiency of the cycle. (d) If an actual heat engine cycle operates between the same temperature limits and produces 5200 kW of power for an air flow rate of 90 kg/s, determine the second law efficiency of this cycle.

6. A fermentation medium is cooled in a double pipe heat exchanger from 371.9 K to 349.7 K. The medium flows inside the inner tube and the cooling water at 288.6 K enters the annular space and flows outside the tube at 319.1 K. Calculate the heat transfer area if the heat transfer rate is 5.14 kJ/s and the overall heat transfer coefficient is 340 W/m ²K. b. For co-current flow of streams < +10

plz write neatly, do not copy and paste solution

Answer: 24.187 °C

A stream of ammonia is cooled from 100oC to 20oC at a rate of 180 kg/hr in the tube side of a double-pipe counter-flow heat exchanger. Water enters the heat exchanger at 10oC at a rate of 250 kg/hr. The outside diameter of the inner tube is 3 cm and the length of the pipe is 7m. Using the log-mean temperature difference, calculate the overall heat transfer coefficient (U) for the heat exchanger. Determine the log-mean temperature difference. Determine the heat transfer coefficient for the heat exchanger.   Cp for ammonia is 5234J/kgK and cp for water is 4180J/kgK.

1. A plastic (k = 0.5 W/m K) pipe carries a coolant at -35 °C with a heat-transfer coefficient of 300 W/m².K. The pipe ID is 3 cm and the OD is 4 cm. The exterior pipe surface is exposed to air at 25°C with a heat-transfer coefficient of 20 W/m²K. Radiative heat transfer may be neglected in this problem. (a) Calculate the rate of heat transfer to the coolant per meter of pipe length. (b) Calculate the temperature of the exterior pipe surface.

please show how to derive h using nusselt equation and solve for qheatloss

Question attached

Design a vapor compression cycle using ammonia as the refrigerant thatwill be used to maintain the temperature of a stream at -20°C. The condenser is air-cooled and the ambient temperature may be assumed to be 25°C. Assume a compressor efficiency of 80% and allow for 2°C of temperature difference between streams in the evaporator and condenser for practical heat transfer.

A stream of ammonia is cooled from 100oC to 20oC at a rate of 180 kg/hr in the tube side of a double-pipe counter-flow heat exchanger. Water enters the heat exchanger at 10oC at a rate of 250 kg/hr. The outside diameter of the inner tube is 3 cm and the length of the pipe is 7m. Using the log-mean temperature difference, calculate the overall heat transfer coefficient (U) for the heat exchanger. Determine the heat transfer rate between the two fluids. Determine the outlet temperature of the water. Determine the heat transfer surface area. Determine the log-mean temperature difference. Determine the heat transfer coefficient for the heat exchanger.   Cp for ammonia is 5234J/kgK and cp for water is 4180J/kgK.