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Pie
3 years ago
12

An air conditioner using refrigerant R-134a as the working fluid and operating on the ideal vapor-compression refrigeration cycl

e is to maintain a space at 22°C while operating its condenser at 1000 kPa.
a. Determine the COP of the system when a temperature difference of 2°C is allowed for the transfer of heat in the evaporator.
Engineering
1 answer:
Oduvanchick [21]3 years ago
6 0

Answer:

COP=13.37

Explanation:

Considering the allowed temperature difference the temperature in the evaporator will be 20°. The enthalpy and entropy at this temperature are obtained from table for the saturated vapor phase:

h_1=261.64 kJ/kg

s_1=0.92254 kJ/kgK

The enthalpy at state 2 is determined from the given condenser pressure and the condition s_2 = s_1 with data from table using interpolation:  

h_2=273.18 kJ/kg

The enthalpy at states 3 and 4 is determined from the saturated liquid value for the condenser pressure from table:  

h_3=h_4=107.34 kJ/kg

the COP is then:

COP=qL/w

       = h_1- h_4/ h_2- h_1

       =13.37

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Answer:

b). Occurs at the outer surface of the shaft

Explanation:

We know from shear stress and torque relationship, we know that

\frac{T}{J}= \frac{\tau }{r}

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Therefore from the above relation we see that

            \tau = \frac{T.r}{J}

Thus torsional shear stress, τ is directly proportional to the radius,r of the shaft.

When r= 0, then τ = 0

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3 years ago
How deep is a 6ft hole?​
Pavlova-9 [17]

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I know this sounds quite deep but it is as deep as a grave

Explanation:

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2 years ago
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In an air standard diesel cycle compression starts at 100kpa and 300k. the compression ratio is 16 to 1. The maximum cycle tempe
KIM [24]

Answer:

\eta=0.60

Explanation:

Given :Take \gamma=1.4 for air

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So T_2=300\times 16^{\gamma-1}

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Now find the cut off ration \rho

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\rho=\frac{2031}{909.42}

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Now by putting the all values

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7 0
3 years ago
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GaryK [48]

Answer:

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Explanation:

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8 0
2 years ago
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The answer is as given in the explanation.

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