Explanation Consider the refrigerant flows at steady state through one inlet and one exit system (throttle valve). Hence, the inlet and exit mass flow rates are equal. m ˙ 1 = m ˙ 2 = m ˙ Write the energy rate balance equation for one inlet and one outlet system. [ Q ˙ 1 + W ˙ 1 + m ˙ ( h 1 + V 1 2 2 + g z 1 ) ] − [ Q ˙ 2 + W ˙ 2 + m ˙ ( h 2 + V 2 2 2 + g z 2 ) ] = Δ E ˙ system (I) Here, the rate of heat transfer is Q ˙ , the rate of work transfer is W ˙ , the enthalpy is h and the velocity is V , the gravitational acceleration is g , the elevation from the datum is z and the rate of change in net energy of the system is Δ E ˙ system ; the suffixes 1 and 2 indicates the inlet and outlet of the system. The refrigerant flows at steady state through the throttle valve. Hence, the rate of change in net energy of the system becomes zero. Δ E ˙ system = 0 Since, it is a throttling process. In this process the enthalpy alone remains constant. Hence, neglect the heat transfer, work transfer, kinetic and potential energies. The Equations (I) reduced as follows. [ 0 + 0 + m ˙ ( h 1 + 0 + 0 ) ] − [ 0 + 0 + m ˙ ( h 2 + 0 + 0 ) ] = 0 m ˙ h 1 − m ˙ h 2 = 0 m ˙ h 1 = m ˙ h 2 h 1 = h 2 (II) At the inlet: The refrigerant is at the state of saturated liquid. Refer Table A-11, “Saturated refrigerant-134a-Temperature table”. Obtain the following properties corresponding to the temperature of 50 ° C - using interpolation method. Write the formula of interpolation method of two variables. y 2 = ( x 2 − x 1 ) ( y 3 − y 1 ) ( x 3 − x 1 ) + y 1 (III) Show the temperature and enthalpy values from the Table A-11 as in below table. S.No. x y Temperature ( T ) ,in °C Enthalpy ( h f ) , in kJ/kg ⋅ K 1 48 120

9th Edition

ISBN: 9781307573022

Author: CENGEL

Publisher: MCG/CREATE

See similar textbooks

Concept explainers

Work and Heat Transfer

It is generally related to thermal engineering which tells about the use, creation, conversion and transfer of heat energy between the systems. It is also considered that to transfer heat from one source to another, transfer of masses is also required. T…

Videos

Question

Chapter 5.5, Problem 64P

To determine

The quality of the refrigerant.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Chapter 5.5, Problem 63P

Chapter 5.5, Problem 65P

Students have asked these similar questions

Refrigerant-134a is throttled from the saturated liquid state at 700 kPa to a pressure of 170.9 kPa. Determine the temperature drop during this process and the final specific volume of the refrigerant. The inlet enthalpy of R-134a is 88.82 kJ/kg and saturation temperature is 26.69°C. P₁= 700 kPa sat. liquid R-134a P₂ kPa The temperature drop is °C. The final specific volume is m³/kg. (Round the final answer to three decimal places.)

An adiabatic capillary tube is used in some refrigeration systems to drop the pressure of the refrigerant from the condenser level to the evaporator level. The R-134a enters the capillary tube as a saturated liquid at 50°C and leaves at –20°C. Determine the quality of the refrigerant at the inlet of the evaporator.

Refrigerant -134a at 200 kPa and 40 C flows through a refrigeration line. Determine its specific volume.

Chapter 5 Solutions

THERMODYNAMICS-SI ED. EBOOK >I<

Ch. 5.5 - Name four physical quantities that are conserved...Ch. 5.5 - Define mass and volume flow rates. How are they...Ch. 5.5 - Does the amount of mass entering a control volume...Ch. 5.5 - Consider a device with one inlet and one outlet....Ch. 5.5 - The ventilating fan of the bathroom of a building...Ch. 5.5 - Air enters a 16-cm-diameter pipe steadily at 200...Ch. 5.5 - A steam pipe is to transport 200 lbm/s of steam at...Ch. 5.5 - A garden hose attached with a nozzle is used to...Ch. 5.5 - A steady-flow compressor is used to compress...Ch. 5.5 - Air enters the 1-m2 inlet of an aircraft engine at...

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.

The quality of the refrigerant.

Solution Summary: The author calculates the energy rate balance equation for one inlet and one outlet system.

Concept explainers

Videos

The quality of the refrigerant.

Want to see the full answer?

Chapter 5 Solutions