Answer:
The tube surface temperature immediately after installation is 120.4°C and after prolonged service is 110.8°C
Explanation:
The properties of water at 100°C and 1 atm are:
pL = 957.9 kg/m³
pV = 0.596 kg/m³
ΔHL = 2257 kJ/kg
CpL = 4.217 kJ/kg K
uL = 279x10⁻⁶Ns/m²
KL = 0.68 W/m K
σ = 58.9x10³N/m
When the water boils on the surface its heat flux is:
For copper-water, the properties are:
Cfg = 0.0128
The heat flux is:
qn = 0.9 * 18703.42 = 16833.078 W/m²
The tube surface temperature immediately after installation is:
Tinst = 100 + 20.4 = 120.4°C
For rough surfaces, Cfg = 0.0068. Using the same equation:
ΔT = 10.8°C
The tube surface temperature after prolonged service is:
Tprolo = 100 + 10.8 = 110.8°C
<u></u> has greater effect.
<u>Explanation</u>:
= Temperature of cold reservoir
= Temperature of hot reservoir
when is decreased by 't',
=
when is increased by 'T'
Answer: Attached below is the missing diagram
answer :
A) 1) Wr > WI, 2) Qc' > Qc
B) 1) QH' > QH, 2) Qc' > Qc
Explanation:
л = w / QH = 1 - Qc / QH and QH = w + Qc
<u>A) each cycle receives same amount of energy by heat transfer</u>
<u>(</u> Given that ; Л1 = 1/3 ЛR )
<em>1) develops greater bet work </em>
WR develops greater work ( i.e. Wr > WI )
<em>2) discharges greater energy by heat transfer</em>
Qc' > Qc
solution attached below
<u>B) If Each cycle develops the same net work </u>
<em>1) Receives greater net energy by heat transfer from hot reservoir</em>
QH' > QH ( solution is attached below )
<em>2) discharges greater energy by heat transfer to the cold reservoir</em>
Qc' > Qc
solution attached below