3- The water in the form of superheated steam with a mass of 1 kg at a pressure of 500 kPa and a temperature of 500 ° C in the piston-cylinder assembly is first cooled to a temperature of 120 ° C in a fixed volume and then the water is cooled and condensed at a constant temperature until it becomes a saturated liquid. a) Draw the T-v diagram of the states. b) Find the work done during the state changes. c) Find the heat transfer from the piston and cylinder assembly to the environment. Note: Changes in kinetic and potential energies are negligible

Just d

6. Determine the temperature of water at a state of P = 400 kPa and h = 3300 kJ/kg.

Stefan-Boltzman law which describes the radiation heat transfer states that, it is proportional to (where, t = temperature in °C T = absolute temperature in °K) A. +4 T4 B. C. D. O 1 t4 1 T4

2. A piston-cylinder device initially contains 0.8 kg of nitrogen gas at 160 kPa and 240 °C. The nitrogen gas is now expanded to a pressure of 100 kPa isothermally. Determine the work boundary during this process. 3. A frictionless piston-cylinder device contains 6 kg vapor at 600 kPa and 400 °C. When heat is transferred to the system, the vapor temperature is increasing up to 500 °C. Calculate the work net during this heat transfer process.

The rate of heat transfer from a body to the surroundings is governed by the following equation: D= hA(Tsur - Tbody) Where dis the heat transfer rate (J/s) h is the heat transfer coefficient A is the heat transfer area (m²) Tsur is the temperature of the surroundings (K) Tpody, is the temperature of the body (K) Find the units for the heat transfer coefficient, h.

An insulated, vertical piston–cylinder device initially contains 15 kg of water, 10 kg of which is in the vapor phase. Initially the pressure is 200 kPa inside the cylinder. A linear spring is connected to the piston therefore the pressure changes linearly with volume (P = m*v+b). Super heated steam at 0.5 MPa and constant temperature is allowed to enter the cylinder from a supply line until all the liquid in the cylinder has just vaporized and the pressure and volume in the cylinder have both doubled.   Determine the final temperature (in ºC) in the cylinder.  Determine the mass of the steam that has entered during this process. Determine the boundary work (in kJ) associated with the system during this process Determine the specific enthalpy (in kJ/kg) of the steam entering the cylinder.

A 7 dm3 rigid tank contains 4.5 kg of saturated water (liquid and vapor) at 38ºC. The tank is slowly heated. a. After a long period of time what do you think happened to the liquid water surface: do you think it raised and reached the top of the tank or it dropped and reached the bottom of it? b. Solve the same problem considering that the amount of water is 0.45 kg instead.

9. SOC high crude oil is to be heated from 15° C to 55° C at the rate of 1,50 ton/h using a stream from the plant. The crude oil is pumped in to the tube and the heating stream is pumped into the shell side of an available heat exchanger. The heating stream enters in to the tube at 150° C and leaves the tube at 110° C. The average properties of both the fluids are given below. The available heat exchanger (1-2 pass) has shell diameter of 23% in. The shell has 324 tubes, ¾ in. OD, BWG 14 (wall thickness), 12 feet long arranged on 1 in. Square pitch and supported by baffles with a 25% cut, spaced at 9 in interval. You need to find the suitability of this exchanger for the purpose. What will be the allowable fouling factor? Heating stream Crude oil cp, J/g. ° C 2.2 2 H, CP 5.2 2.9 P, kg/m3 k, W/m. C 866 822 0.12 0.138

Air is contained in a vertical piston–cylinder assembly fitted with an electrical resistor. The atmosphere exerts a pressure of 101.325 kPa on the top of the piston, which has a mass of 50 kg and a face area of 0.10 m 2 . Electric current passes through the resistor, and the volume of the air slowly increases by 2 ft3 while its pressure remains constant. The mass of the air is 0.32 kg, and its specific internal energy increases by 20 Btu/lb. The air and piston are at rest initially and finally. The piston–cylinder material is a ceramic composite and thus a good insulator. Friction between the piston and cylinder wall can be ignored, and the local acceleration of gravity is g = 32.0 ft/s2 Determine the heat transfer from the resistor to the air, in Btu, for a system consisting of (a) the air alone, (b) the air and the piston. Also draw the schematic diagram. Hint: Refer to example