Chapter 7, Problem 7.80P

Parts A-C have already been answered in a previous question I sub A counterflow heat exchanger operates at steady state while being well-insulated from the surroundings with air and ammonia flowing in separate streams. Ammonia enters at state 1 with -30°C and a quality of 30% and exits at state 2 as saturated vapor at -30°C. Air enters at state 3 with pressure 1 bar and temperature 295 K and exits at state 4 with pressure 1 bar and temperature 265 K. The flow rate of air is 10 kg/s. Ignore kinetic and potential energy effects, and take the dead state as 1 bar and 300 K. a. Describe the heat transfer inside the heat exchanger (what is transferring heat to what?) b. Determine the specific enthalpy of each state, in kJ/kg. c. Determine the mass flow rate of ammonia, in kg/s. d. Determine the rate of exergy destruction within the heat exchanger, in kW.e. Devise and evaluate an exergetic efficiency for the heat exchanger.

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1. For the pasteurization process, the cold milk with a 4°C temperature value enters the first heat exchanger system. The milk exits the first eat exchanger at 27 °C and enter the 2nd heat exchanger system and exit 54° C. Finally, the milk exit from the 3rd heat exchanger at 72°C (pasteurization temperature). The heat transfer is conducted by steam. The modeling procedures for system controlling is performed based on the initial cold milk temperature. For this system, a. Define process control elements and process dynamic. b. Feed forward or feedback system why? c. How could you express transfer function for this system

I need help going through the process to solve this problem, I think I have a general idea, but want to make sure I am doing it correctly. A counterflow heat exchanger operates at steady state while being well-insulated from the surroundings with air and ammonia flowing in separate streams. Ammonia enters at state 1 with -30°C and a quality of 30% and exits at state 2 as saturated vapor at -30°C. Air enters at state 3 with pressure 1 bar and temperature 295 K and exits at state 4 with pressure 1 bar and temperature 265 K. The flow rate of air is 10 kg/s. Ignore kinetic and potential energy effects, and take the dead state as 1 bar and 300 K. a. Describe the heat transfer inside the heat exchanger (what is transferring heat to what?) b. Determine the specific enthalpy of each state, in kJ/kg. c. Determine the mass flow rate of ammonia, in kg/s. d. Determine the rate of exergy destruction within the heat exchanger, in kW.e. Devise and evaluate an exergetic efficiency for the heat…

Question 20 Separate streams of steam and air flow through the turbine and heat exchanger arrangement shown in the figure below, where mass flow rate m5 is 2000 kg/min and power output Wt1 is 12,000 kW. Steady-state operating data are provided on the figure. Heat transfer with the surroundings can be neglected, as can all kinetic and potential energy effects. m5 Steam in Turbine T₁ = 600°C P₁ = 20 bar Determine: (a) T3, in K. W₁l T₂ = 400°C P2= 10 bar > 6 VT6 = 1200 K P6 = 1 bar kW P3= 10 bar T3=? www tw Heat exchanger Turbine 2 Air in (b) the power output of the second turbine, in kW. W₁2=? T5 = 1500 K -5 P5= 1.35 bar m5 T₁ = 240°C P4 = 1 bar

The figure below provides steady-state data for a throttling valve in series with a heat exchanger. Saturated liquid Refrigerant 134a enters the valve at a pressure of 9 bar and is throttled to a pressure of p2 = 1 bar. The refrigerant then enters the heat exchanger, exiting at a temperature of 10°C with no significant decrease in pressure. In a separate stream, liquid water at 1 bar enters the heat exchanger at a temperature of 25°C with a mass flow rate of m4 = 4 kg/s and exits at 1 bar as liquid at a temperature of 15°C. Stray heat transfer and kinetic and potential energy effects can be ignored. -Heat exchanger 1 2 3 wwww P3 = P2 T3 = 10°C Saturated liquid R-134a at p, = 9 bar Valve P2 5 T5 = 15°C P5 = P4 Water T = 25°C P4 = 1 bar Determine: (a) the temperature, in °C, of the refrigerant at the exit of the valve. (b) the mass flow rate of the refrigerant, in kg/s.

The figure below provides steady-state data for a throttling valve in series with a heat exchanger. Saturated liquid Refrigerant 134a enters the valve at a pressure of 9 bar and is throttled to a pressure of p2 = 2 bar. The refrigerant then enters the heat exchanger, exiting at a temperature of 10°C with no significant decrease in pressure. In a separate stream, liquid water at 1 bar enters the heat exchanger at a temperature of 25°C with a mass flow rate of m˙4= 4 kg/s and exits at 1 bar as liquid at a temperature of 15°C. Stray heat transfer and kinetic and potential energy effects can be ignored.   Determine:(a) the temperature, in °C, of the refrigerant at the exit of the valve.(b) the mass flow rate of the refrigerant, in kg/s.

Draw a figure or FBD that will support the problem. Explain each step by step formula.

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