Chapter 7, Problem 7.70P

A heat exchanger, shown below, is used to cool an air flow from 550 K to 250 K, both states at 1 MPa. The coolant is a water flow at 30 °C, 0.1 MPa. If the water leaves as saturated vapor, 0.1 MPa. 1 air 3 water

R-134a is throttled in a line flowing at 25°C, 750 kPa with negligible kinetic energy to a pressure of 165 kPa. Find the exit temperature and the ratio of exit pipe diameter to that of the inlet pipe (Dex/D;n) so the velocity stays constant.

Steam to a turbine at a mass flow rate of 1.4 kg/s, 700 kPa pressure and 400 °C enters the temperature. Steam at 100 kPa pressure and 1.4 m3/kg specific volume exits the turbine. Heat transfer from turbine to environment 50 kW, with turbine Since the boundary temperature between the environment is 70 °C, a) Find the power produced by the turbine, entropy produced in the turbine and isentropic efficiency of the turbine. Note: The changes in kinetic and potential energies will be neglected and T (K) = 273 + °C will be taken.

occuring when a process with air, the entropy goes up by 0.60 kJ/kg·K. 11 is the pressure compression ratio. 300K is the initial temperature. What is the final temperature if it is a constant specific heat and if it is a variable specific heat? When Rair = 0.287 and cp = 1.005 kJ/kg·K.

Steam flows isentropically through a nozzle from 1517Kpa, 288degC and 965kPa. Mass is 454g/s Find: 9. Final Temperature 10. Work (identify if steady or non-flow work)

K) that undergo an K-K 13. There are 1.5 Kgof a gas where K = 1.3 and R = 0.38 tsochoric process from pi = 0.552 MPa, t, = 58.5°C top2 = 1.66 MPa. During the process, there added 100 KJ of heat. Compute the heat transferred, change of internal energy and the change of entropy. %3D

Air is compressed from 120 kPa and 350 K to 1200 kPa and 750 K. a) Calculate the change in specific entropy As of the air using constant specific heat capacities at 550 K and equations based on cp, Cv, and the heat capacity ratio k. b) Calculate the change in specific entropy As of the air using equations and table values (A-17), which account for the changes in heat capacities with temperature. c) What will the temperature at the end of the compression process T2, be, if the pressure after compression is 1200 kPa, the compression process is isentropic, and you use constant specific heat capacities at 550 K and equations based on Cp, Cv, and the heat capacity ratio k. d) What will the temperature at the end of the compression process T2, be, if the pressure after compression is 1200 kPa, the compression process is isentropic, and you account for changes in heat capacities with temperature by using corresponding equations and table values? e) Calculate the deviation between the results…

Air is expanded from 4 MPa and 1080 K to 100 kPa and 450 K.a) Calculate the air's change in specific entropy (delta s)using constant specific heat capacities at750 K and equations based on cP, cV and the heat capacity ratio k.

Problem 4.01. A carnot refrigerator (carnot cycle heat pump in reverse) operating between Th and Te is used to cool and freeze a bottle of water, volume V, at a temperature To < Th to freezing temperature T (known density Pw, heat capacity cw). (a) Find the work required to cool and freeze the water. (b) Find the change in entropy in the heat baths, and use it to place a limit on the change in entropy of the water (without calculating the entropy change in the water). The C.O.P. of a carnot refrigerator: KR= Qc = W Te Th-Te