Determine the final phase of the water in the tank

Question

Problem 1:

Water in a piston-cylinder assembly with an initial volume of 0.01 m3 has an initial temperature of 120°C and an initial quality of 0.4 (State 1). The water is heated at constant pressure to a temperature of 200^oC (State 2). The water is then compressed at constant temperature until the first droplet of liquid water starts to condense (State 3).

(a) Draw the states on a T-v diagram.

(b) Find the mass of water (kg) in the cylinder.

(c) Calculate the work W12 (kJ) and heat transfer Q12 (kJ) for the constant pressure heat transfer process.

(d) Find the volume of the system (m3) at State 3.

Problem 2:

A 2-kg block of ice with an initial temperature of -20^oF is dropped into an insulated tank containing 10 kg of liquid water at an initial temperature of 70^oF. The specific heat of the solid ice is 0.477 Btu/(lbm ^oF), and the specific heat of the liquid water is 1.00 Btu/(lbm ^oF). The heat of melting for water is 144 Btu/lbm. Assume that all of these quantities are independent of temperature.

(a) Determine the final phase of the water in the tank.

(b) Calculate the final temperature (^oF) of the water in the tank.

Problem 3:

Determine the specific volume of propane (C3H8) at 18 bar and 100^oC using:

(a) Table A-18.

(b) Figure A-1.

(c) The ideal gas equation of state.

(d) Compare and comment on the values found in parts (a)-(c).

Answer 1

For the following mechanics numerical problems, solve and provide solutions for each by applying the appropriate principles and formulas. Question: Water in the piston-cylinder assembly by means of an initial volume of 0.01 m3 consists of an initial temperature of 120°C and an initial quality of 0.4 (State 1). The water is heated at constant pressure to the temperature of 200oC (State 2). The water is then compressed at constant temperature till the Ist droplet of liquid water begins to condense (State 3). 1) Draw the states on the T-v diagram. 2) Determine the mass of water (kg) in the cylinder. 3) Compute the work W12 (kJ) and heat transfer Q12 (kJ) for the constant pressure heat transfer procedure. 4) Determine the volume of the system (m3) at State 3.