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HEAT+MASS TRANSFER:FUND.+APPL.
- (a) In the thermodynamic laboratory, student Ali prepared a piston-cylinder device which contains refrigerant-134a at 1000 kPa and 50°C. The mass of the refrigerant is 6 kg. The next step of the experiment involves cooling the refrigerant at constant pressure until its state become liquid at 24°C. Show the process on T-v diagram and determine the heat loss from the system. (b) A heat exchanger as shown in Figure 1 is used to cool water flowing in at 1 kg/s water, 10 kPa and quality 0.95 to saturated liquid at 10 kPa. The cooling fluid is water taken from a lake at 20°C and it exit the heat exchanger at 30°C. Calculate the flow rate of cooling water. Assume that the heat exchange is well insulated and there is no heat loss. Lake water Figure 1: Heat exchangerarrow_forward3. A room is to be heated by 1000 kg of a liquid contained in a tank placed in the room. The room is not well insulated and loses 192, 000 kJ of heat to the outside. The room is kept at a constant temperature of 20°C. If the final temperature of the liquid is 25°C, determine its initial temperature. If needed use: For the liquid Cp= 4 kJ/kg.K For Air: R=0.287 kJ/kg.K liquid tank C₂ = 0.718 kJ/kg.K 192,000 kJ C₂ = 1.005 kJ/kg.Karrow_forwardQuestion 1 (a) In the thermodynamic laboratory, student Ali prepared a piston-cylinder device which contains refrigerant-134a at 1000 kPa and 50°C. The mass of the refrigerant is 6 kg. The next step of the experiment involves cooling the refrigerant at constant pressure until its state become liquid at 24°C. Show the process on T-v diagram and determine the heat loss from the system.arrow_forward
- Refrigerant-134a (R-134a) enters the expansion valve of a refrigeration system at 650 kPa with a quality of 20%. The pressure of R-134a at the outlet is 200 kPa. a)Determine the temperature of R-134a at the outlet in oC. Calculate the difference of internal energy between the outlet and inlet in kJ/kgarrow_forward6. A well-sealed room contains 60 kg of air at 200 kPa and 25°C. Now solar energy enters the room at an average rate of 0.8 kJ/s while a 120-W fan is turned on to circulate the air in the room. If heat transfer through the walls is negligible, Solve for the air temperature in the room in 30 min. (3 DECIMAL IN FINAL ANSWER PLS)arrow_forwardQ1/ A frictionless piston–cylinder device initially contains 200 L of saturated liquid refrigerant-134a. The piston is free to move, and its mass is such that it maintains a pressure of 900 kPa on the refrigerant. The refrigerant is now heated until its temperature rises to 70°C. Calculate the work done during this process. Answer: 5571 kJarrow_forward
- A certain quantity of air in a closed vessel with a fixed volume of 0.15 m3 exerts 1 MPa pressure at 500 K. If the vessel is cooled while the pressure is reduced to 350 kPa, determine the heat transfer during the process.arrow_forwardNOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. A piston-cylinder device initially contains 1 kg saturated liquid water at 200°C. Now heat is transferred to the water until the volume quadruples and the cylinder contains saturated vapor only. The saturated liquid properties of water at 200°C 3 are vf= 0.001157 m³/kg and uf= 850.46 kJ/kg (Table A-4). Water 71 kg 200°C Q Determine the internal energy change of the water. The change in internal energy is kJ.arrow_forwardThermodynamics: A rigid cylinder is filled with refrigerant-134a at 18°C. At this state, 40 percent of the mass is vapor. A valve at the bottom is opened, and refrigerant is withdrawn outside.Heat is transferred to the tank such that the temperature in the tank remains constant and the refrigerant fills the tank all the time (V1= V2). Determine the amount of heat that must be transferred by the time one-fourth of the total mass has been withdrawn. The tank volume is 0.1-m3. Clearly show work.arrow_forward
- 1- A piston-cylinder device whose piston is resting on top of stops initially contains 0.5 kg of helium gas at 100 kPa and 25°C. The mass of the piston is such that 500 kPa of pressure is required to raise it. (1) How much heat must be transferred to the helium before the piston starts rising and (2) show the process on P-V diagram 2- A mass of 5 kg of saturated liquid water at 200 kPa is heated at a constant pressure until the temperature reaches 300°C. Find: (1) Au,Ah & Av, (2) the work done during this process, (3) the amount of heat added to the system, and (4) show the process on T - v diagramarrow_forwardA piston-cylinder device whose piston is resting on top of a set of stops initially contains 0.6 kg of helium gas at 100 kPa and 25°C. The mass of the piston is such that 500 kPa of pressure is required to raise it. How much heat must be transferred to helium before the piston starts rising? The specific heat of helium at room temperature is cy= 3.1156 kJ/kg-K (Table A-2). The amount of heat to be transferred to helium is kJ.arrow_forwardA piston-cylinder device contains 0.1 m3 of refrigerant 134a at 0.24 MPa and 40ºC. Initially the piston is fixed with a pin. Heat is transferred now to the refrigerant from a source at 100ºC until the pressure rises to 0.28 MPa. Then, heat is given to an environment with a temperature of 25ºC at a constant pressure (the pin is pulled and in this case, the mass of the piston and the masses on it and the pressure created by the atmospheric pressure are equal to the pressure inside the cylinder) the temperature is brought to a temperature of 50ºC. a) Determine the heat and work interaction for each process b) Sketch the P-v and T-s diagrams of the processes with respect to the saturation lines c) Determine the entropy change of the refrigerant 134a during these two processes d) Determine the entropy generation during these processes. Are these processes appropriate to 2. law of thermodynamics, explainarrow_forward
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