
(a)
The mass flow rate of the refrigerant through the upper cycle.
(a)

Answer to Problem 59P
The mass flow rate of the refrigerant through the upper cycle is
Explanation of Solution
Express the specific enthalpy at state 2 using Carnot efficiency.
Here, specific enthalpy at state 1, 2 and 2s is
Express specific enthalpy at state 3.
Here, specific enthalpy at saturated liquid and pressure of
Write the specific enthalpy at state 3 is equal to state 4 due to throttling process.
Here, specific enthalpy at state 3 and 4 is
Express specific enthalpy at state 5.
Here, specific enthalpy at saturated vapor and pressure of
Express specific entropy at state 5.
Here, specific entropy at saturated vapor and pressure of
Express the specific enthalpy at state 6 using Carnot efficiency.
Here, specific enthalpy at state 5, 6 and 6s is
Express specific enthalpy at state 7.
Here, specific enthalpy at saturated liquid and pressure of
Write the specific enthalpy at state 7 is equal to state 8 due to throttling process.
Here, specific enthalpy at state 7 and 8 is
Express the mass flow rate of the refrigerant through the upper cycle.
Here, mass flow rate of the refrigerant through the lower cycle is
Conclusion:
Refer Table A-12, “saturated refrigerant-134a-pressure table”, and write the properties corresponding to pressure of
Here, specific entropy and enthalpy at state 1 is
Refer Table A-13, “superheated refrigerant 134a”, and write the specific enthalpy at state 2s corresponding to pressure at state 2 of
Write the formula of interpolation method of two variables.
Here, the variables denote by x and y is specific entropy at state 2 and specific enthalpy at state 2s respectively.
Show the specific enthalpy at state 2s corresponding to specific entropy as in Table (1).
Specific entropy at state 2 |
Specific enthalpy at state 2s |
0.9384 | 263.48 |
0.9420 | |
0.9704 | 273.03 |
Substitute
Thus, the specific enthalpy at state 2s is,
Substitute
Perform unit conversion of pressure at state 3 and 5 from
Refer Table A-12, “saturated refrigerant-134a-pressure table”, and write the property corresponding to pressure at state 3
Substitute
Substitute
Refer Table A-12, “saturated refrigerant-134a-pressure table”, and write the properties corresponding to pressure of
Substitute
Substitute
Perform unit conversion of pressure at state 6 from
Refer Table A-13, “superheated refrigerant 134a”, and write the specific enthalpy at state 6s corresponding to pressure at state 6 of
Show the specific enthalpy at state 6s corresponding to specific entropy as in Table (2).
Specific entropy at state 2 |
Specific enthalpy at state 6s |
0.9107 | 276.17 |
0.9271 | |
0.9389 | 285.47 |
Use excels and tabulates the values from Table (2) in Equation (X) to get,
Substitute
Refer Table A-12, “saturated refrigerant-134a-pressure table”, and write the property corresponding to pressure at state 7
Substitute
Substitute
Substitute
Hence, the mass flow rate of the refrigerant through the upper cycle is
(b)
The rate of heat removal from the refrigerated space.
(b)

Answer to Problem 59P
The rate of heat removal from the refrigerated space is
Explanation of Solution
Express the rate of heat removal from the refrigerated space.
Conclusion:
Substitute
Hence, the rate of heat removal from the refrigerated space is
(c)
The COP of the refrigerator.
(c)

Answer to Problem 59P
The COP of the refrigerator is
Explanation of Solution
Express the power input.
Express the COP of the refrigerator.
Conclusion:
Substitute
Substitute
Hence, the COP of the refrigerator is
Want to see more full solutions like this?
Chapter 11 Solutions
Thermodynamics: An Engineering Approach ( 9th International Edition ) ISBN:9781260092684
- **Problem 8-45.** The man has a mass of 60 kg and the crate has a mass of 100 kg. If the coefficient of static friction between his shoes and the ground is \( \mu_s = 0.4 \) and between the crate and the ground is \( \mu_c = 0.3 \), determine if the man is able to move the crate using the rope-and-pulley system shown. **Diagram Explanation:** The diagram illustrates a scenario where a man is attempting to pull a crate using a rope-and-pulley system. The setup is as follows: - **Crate (C):** Positioned on the ground with a rope attached. - **Rope:** Connects the crate to a pulley system and extends to the man. - **Pulley on Tree:** The rope runs over a pulley mounted on a tree which redirects the rope. - **Angles:** - The rope between the crate and tree forms a \(30^\circ\) angle with the horizontal. - The rope between the tree and the man makes a \(45^\circ\) angle with the horizontal. - **Man (A):** Pulling on the rope with the intention of moving the crate. This arrangement tests the…arrow_forwardplease solve this problems follow what the question are asking to do please show me step by steparrow_forwardplease first write the line action find the forces and them solve the problem step by steparrow_forward
- please solve this problem what the problem are asking to solve please explain step by step and give me the correct answerarrow_forwardplease help me to solve this problem step by steparrow_forwardplease help me to solve this problem and determine the stress for each point i like to be explained step by step with the correct answerarrow_forward
- please solve this problem for me the best way that you can explained to solve please show me the step how to solvearrow_forwardplese solbe this problem and give the correct answer solve step by step find the forces and line actionarrow_forwardplease help me to solve this problems first write the line of action and them find the forces {fx=0: fy=0: mz=0: and them draw the shear and bending moment diagram. please explain step by steparrow_forward
- please solve this problem step by step like human and give correct answer step by steparrow_forwardPROBLEM 11: Determine the force, P, that must be exerted on the handles of the bolt cutter. (A) 7.5 N (B) 30.0 N (C) 52.5 N (D) 300 N (E) 325 N .B X 3 cm E 40 cm cm F = 1000 N 10 cm 3 cm boltarrow_forwardUsing the moment-area theorems, determine a) the rotation at A, b) the deflection at L/2, c) the deflection at L/4. (Hint: Use symmetry for Part a (θA= - θB, or θC=0), Use the rotation at A for Parts b and c. Note that all deformations in the scope of our topics are small deformation and for small θ, sinθ=θ).arrow_forward
- Refrigeration and Air Conditioning Technology (Mi...Mechanical EngineeringISBN:9781305578296Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill JohnsonPublisher:Cengage Learning
