Question

(Answer five questions) Note: Take: R.-8.314kJ/kg K. For air c=1.005kJ/kg K & y=1.4 Mc =12kg/kmol, Mo. -32 kg/kmol, Myz =28 kg/kmol, M.,=29 kg/kmol, MH2 =28 kg/kmol i. Q1: A- Answer false or true and discusse the followings: For an adiabatic system d. 20. ii. It is impossible to construct a device that operates in a cycle and produces no effect other than the transfer of heat from a cold body to a warmer one without the aid of some external energy. iii.C.O.P of the heat pump is the same as C.O.P of refrigerator. (6 marks) B-0.01Kg of air at Ibar and 25°C receives heat at constant volume until its pressure doubled; it then receives heat at constant pressure until its volume doubled. Determine the change of entropy during each process and the final air temperature. (8 marks) Q2: A-Drive an expression of entropy change during constant pressure process. (4 marks) B- A refrigerator working on reversed Carnot cycle having Ikg of carbon dioxide (COC=1.235kJ/kg K &y=1.3). This refrigerator operates between reservoirs at (-15°C) and (27°C). At the beginning of the high-temperature heat rejection, the pressure is IMPa. During this process the volume ratio is 1:4. Draw the cycle on P-V & T-S diag. and analyze each of the four processes in the cycle and determine:- 1. The pressure, volume, and temperature at each point. II. The work and heat transfer for each process. (10 marks) Q3: A-Define the turbine isentropic efficiency, write an expression in term of fluid temperatures. (4 marks) B- Air enters a compressor at temperature and pressure of 30°C, Ibar respectively. The actual exit air temperature is 180°C. The compressor isentropic efficiency is estimated to be 80%. Calculate the compressor exit pressure and the actual compression index (n). (10 marks) Q4: A- A heat pump has working temperatures in evaporator and condenser coils 0º C and 25°C respectively. What is the maximum C.O.P possible? If the actual heat pump has a C.O.P of 60% of the maximum, calculate the power required in kW per kW of heating load. (7 marks) B- The gravimetric analysis of air is given by: Oxygen 23.14%, Nitrogen 76.81%, and Carbon dioxide 0.05% Compute the gas constant and the molecular weight of air. (7 marks)

It is possible to dissolve this chain. Your material is hot. I want the solution as soon as possible, half an hour

Answer 1

Thanks for your lovely statement. However, experts are allowed to solve only one question in case of multiple questions as HOMEWORKLIB RULES honour code. Please upload question again and mention question no.