Answer:
See attached image for diagrams and solution
Answer:
A civil engineer.
Explanation:
Civil engineering is the science that deals with the design, creation and maintenance of constructions for civil use on the earth's surface. Thus, this specialty seeks to adapt soils to the needs of life in society, creating buildings, bridges, and all other constructions adapted to civil life, while taking care of the correct use of soils and the correct distribution of spaces and resources. to be used for such constructions.
Answer:
![L=107.6m](https://tex.z-dn.net/?f=L%3D107.6m)
Explanation:
Cold water in: ![m_{c}=1.2kg/s, C_{c}=4.18kJ/kg\°C, T_{c,in}=20\°C, T_{c,out}=80\°C](https://tex.z-dn.net/?f=m_%7Bc%7D%3D1.2kg%2Fs%2C%20C_%7Bc%7D%3D4.18kJ%2Fkg%5C%C2%B0C%2C%20T_%7Bc%2Cin%7D%3D20%5C%C2%B0C%2C%20T_%7Bc%2Cout%7D%3D80%5C%C2%B0C)
Hot water in: ![m_{h}=2kg/s, C_{h}=4.18kJ/kg\°C, T_{h,in}=160\°C, T_{h,out}=?\°C](https://tex.z-dn.net/?f=m_%7Bh%7D%3D2kg%2Fs%2C%20C_%7Bh%7D%3D4.18kJ%2Fkg%5C%C2%B0C%2C%20T_%7Bh%2Cin%7D%3D160%5C%C2%B0C%2C%20T_%7Bh%2Cout%7D%3D%3F%5C%C2%B0C)
![D=1.5cm=0.015m, U=649W/m^{2}K, LMTD=?\°C, A_{s}=?m^{2},L=?m](https://tex.z-dn.net/?f=D%3D1.5cm%3D0.015m%2C%20U%3D649W%2Fm%5E%7B2%7DK%2C%20LMTD%3D%3F%5C%C2%B0C%2C%20A_%7Bs%7D%3D%3Fm%5E%7B2%7D%2CL%3D%3Fm)
Step 1: Determine the rate of heat transfer in the heat exchanger
![Q=m_{c}C_{c}(T_{c,out}-T_{c,in})](https://tex.z-dn.net/?f=Q%3Dm_%7Bc%7DC_%7Bc%7D%28T_%7Bc%2Cout%7D-T_%7Bc%2Cin%7D%29)
![Q=1.2*4.18*(80-20)](https://tex.z-dn.net/?f=Q%3D1.2%2A4.18%2A%2880-20%29)
![Q=1.2*4.18*(80-20)](https://tex.z-dn.net/?f=Q%3D1.2%2A4.18%2A%2880-20%29)
![Q=300.96kW](https://tex.z-dn.net/?f=Q%3D300.96kW)
Step 2: Determine outlet temperature of hot water
![Q=m_{h}C_{h}(T_{h,in}-T_{h,out})](https://tex.z-dn.net/?f=Q%3Dm_%7Bh%7DC_%7Bh%7D%28T_%7Bh%2Cin%7D-T_%7Bh%2Cout%7D%29)
![300.96=2*4.18*(160-T_{h,out})](https://tex.z-dn.net/?f=300.96%3D2%2A4.18%2A%28160-T_%7Bh%2Cout%7D%29)
![T_{h,out}=124\°C](https://tex.z-dn.net/?f=T_%7Bh%2Cout%7D%3D124%5C%C2%B0C)
Step 3: Determine the Logarithmic Mean Temperature Difference (LMTD)
![dT_{1}=T_{h,in}-T_{c,out}](https://tex.z-dn.net/?f=dT_%7B1%7D%3DT_%7Bh%2Cin%7D-T_%7Bc%2Cout%7D)
![dT_{1}=160-80](https://tex.z-dn.net/?f=dT_%7B1%7D%3D160-80)
![dT_{1}=80\°C](https://tex.z-dn.net/?f=dT_%7B1%7D%3D80%5C%C2%B0C)
![dT_{2}=T_{h,out}-T_{c,in}](https://tex.z-dn.net/?f=dT_%7B2%7D%3DT_%7Bh%2Cout%7D-T_%7Bc%2Cin%7D)
![dT_{2}=124-20](https://tex.z-dn.net/?f=dT_%7B2%7D%3D124-20)
![dT_{2}=104\°C](https://tex.z-dn.net/?f=dT_%7B2%7D%3D104%5C%C2%B0C)
![LMTD = \frac{dT_{2}-dT_{1}}{ln(\frac{dT_{2}}{dT_{1}})}](https://tex.z-dn.net/?f=LMTD%20%3D%20%5Cfrac%7BdT_%7B2%7D-dT_%7B1%7D%7D%7Bln%28%5Cfrac%7BdT_%7B2%7D%7D%7BdT_%7B1%7D%7D%29%7D)
![LMTD = \frac{104-80}{ln(\frac{104}{80})}](https://tex.z-dn.net/?f=LMTD%20%3D%20%5Cfrac%7B104-80%7D%7Bln%28%5Cfrac%7B104%7D%7B80%7D%29%7D)
![LMTD = \frac{24}{ln(1.3)}](https://tex.z-dn.net/?f=LMTD%20%3D%20%5Cfrac%7B24%7D%7Bln%281.3%29%7D)
![LMTD = 91.48\°C](https://tex.z-dn.net/?f=LMTD%20%3D%2091.48%5C%C2%B0C)
Step 4: Determine required surface area of heat exchanger
![Q=UA_{s}LMTD](https://tex.z-dn.net/?f=Q%3DUA_%7Bs%7DLMTD)
![300.96*10^{3}=649*A_{s}*91.48](https://tex.z-dn.net/?f=300.96%2A10%5E%7B3%7D%3D649%2AA_%7Bs%7D%2A91.48)
![A_{s}=5.07m^{2}](https://tex.z-dn.net/?f=A_%7Bs%7D%3D5.07m%5E%7B2%7D)
Step 5: Determine length of heat exchanger
![A_{s}=piDL](https://tex.z-dn.net/?f=A_%7Bs%7D%3DpiDL)
![5.07=pi*0.015*L](https://tex.z-dn.net/?f=5.07%3Dpi%2A0.015%2AL)
![L=107.57m](https://tex.z-dn.net/?f=L%3D107.57m)
120 volt divided by 22 ampere
= 5.4545454545455 ohm (Ω)
P = V × I
= 120 volt × 22 ampere
= 2640 watt (W)