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Answer:
Hello your question has some missing information below are the missing information
The refrigerant enters the compressor as saturated vapor at 140kPa Determine The coefficient of performance of this heat pump
answer : 2.49
Explanation:
For vapor-compression refrigeration cycle
P1 = P4 ; P1 = 140 kPa
P2( pressure at inlet ) = P3 ( pressure at outlet ) ; P2 = 800 kPa
<u>From pressure table of R 134a refrigerant</u>
h1 ( enthalpy of saturated vapor at 140kPa ) = 239.16 kJ/kg
h2 ( enthalpy of saturated liquid at P2 = 800 kPa and t = 60°C )
= 296.8kJ/kg
h3 ( enthalpy of saturated liquid at P3 = 800 kPa ) = 95.47 kJ/kg
also h4 = 95.47 kJ/kg
To determine the coefficient of performance
Cop = ( h1 - h4 ) / ( h2 - h1 )
∴ Cop = 2.49
Answer:
Final length of the rod = 13.90 in
Explanation:
Cross Sectional Area of the polythene rod, A = 0.04 in²
Original length of the polythene rod, l = 10 inches
Tensile modulus for the polymer, E = 25,000 psi
Viscosity, ![\eta = 1*10^{9} psi -sec](https://tex.z-dn.net/?f=%5Ceta%20%3D%201%2A10%5E%7B9%7D%20psi%20-sec)
Weight = 358 lbs - f
time, t = 1 hr = 3600 sec
Stress is given by:
![\sigma = \frac{Force}{Area} \\\sigma = \frac{358}{0.04} \\\sigma = 8950 psi](https://tex.z-dn.net/?f=%5Csigma%20%3D%20%5Cfrac%7BForce%7D%7BArea%7D%20%5C%5C%5Csigma%20%3D%20%5Cfrac%7B358%7D%7B0.04%7D%20%5C%5C%5Csigma%20%3D%208950%20psi)
Based on Maxwell's equation, the strain is given by:
![strain = \sigma ( \frac{1}{E} + \frac{t}{\eta} )\\Strain = 8950 ( \frac{1}{25000} + \frac{3600}{10^{9} } )\\Strain = 0.39022](https://tex.z-dn.net/?f=strain%20%3D%20%5Csigma%20%28%20%5Cfrac%7B1%7D%7BE%7D%20%2B%20%5Cfrac%7Bt%7D%7B%5Ceta%7D%20%29%5C%5CStrain%20%3D%208950%20%28%20%5Cfrac%7B1%7D%7B25000%7D%20%2B%20%5Cfrac%7B3600%7D%7B10%5E%7B9%7D%20%7D%20%29%5C%5CStrain%20%3D%200.39022)
Strain = Extension/(original Length)
0.39022 = Extension/10
Extension = 0.39022 * 10
Extension = 3.9022 in
Extension = Final length - Original length
3.9022 = Final length - 10
Final length = 10 + 3.9022
Final length = 13.9022 in
Final length = 13.90 in