The container truck engine operated on the diesel cycle with a compression ratio of 12. Assume the mass of air in the engine is conserved. At the start of the compression process, the air is at 1 atm and 30 oC. 400 kJ/kg of heat is removed from the air during the constant-volume heat rejection process. The ratio of . Through the diesel cycle, 20% of the work done by the air is used to operate the vehicle's refrigeration and heat pump system. One diesel cycle took 0.7s to complete. The heat rejection from the refrigeration and heat pump system is 800 kJ. The refrigeration system uses R-134a as the working fluid and operates between 100 kPa and 1200 kPa pressure limits. cp = 1.005 kJ/kg/K, cv = 0.7177 kJ/kg/K, R = 8.314J/mol/K, Molecular mass of air= 29g/mol. 1) Calculate the temperature at the start of the heat rejection process. 2) Calculate the temperature at the end of the heat addition process. 3) Calculate the temperature at the start of the heat addition process. 4) Calculate the specific heat addition. 5) Calculate the thermal efficiency. 6) Calculate the cyclical diesel engine’s net work done on the 0.8 kg of air. 7) Calculate the heat removed from the refrigerated space. 8) Calculate the coefficient of performance of the refrigeration system. 9) Calculate the mass flow rate of the refrigerant. 10) For the container truck, propose which heat engine cycle is preferred and explain the reasons.
The container truck engine operated on the diesel cycle with a compression ratio of 12. Assume the mass of air in the engine is conserved. At the start of the compression process, the air is at 1 atm and 30 oC. 400 kJ/kg of heat is removed from the air during the constant-volume heat rejection process. The ratio of .
Through the diesel cycle, 20% of the work done by the air is used to operate the vehicle's refrigeration and heat pump system. One diesel cycle took 0.7s to complete. The heat rejection from the refrigeration and heat pump system is 800 kJ.
The refrigeration system uses R-134a as the working fluid and operates between 100 kPa and 1200 kPa pressure limits.
cp = 1.005 kJ/kg/K, cv = 0.7177 kJ/kg/K, R = 8.314J/mol/K, Molecular mass of air= 29g/mol.
1) Calculate the temperature at the start of the heat rejection process.
2) Calculate the temperature at the end of the heat addition process.
3) Calculate the temperature at the start of the heat addition process.
4) Calculate the specific heat addition.
5) Calculate the thermal efficiency.
6) Calculate the cyclical diesel engine’s net work done on the 0.8 kg of air.
7) Calculate the heat removed from the refrigerated space.
8) Calculate the coefficient of performance of the refrigeration system.
9) Calculate the mass flow rate of the refrigerant.
10) For the container truck, propose which heat engine cycle is preferred and explain the reasons.
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