answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Charra [1.4K]
2 years ago
4

Hot engine oil with heat capacity rate of 4440 W/K (product of mass flow rate and specific heat) and an inlet temperature of 150

ºC flows through a double pipe heat exchanger. The double pipe heat exchanger is constructed using a 1.5-m-long copper pipe (k = 250 W/m.K) with an inner tube of inside diameter 2 cm and outside tube diameter of 2.25 cm. The inner diameter of the outer tube of the double pipe heat exchanger is 6 cm. Oil flowing at a rate of 2 kg/s through inner tube exits the heat exchanger at a temperature of 50ºC. The cold fluid, i.e., water enters the heat exchanger at 20ºC and exits at 108ºC. Assume the fouling factor on the oil side and water side to be 0.00015 m2.K/W and 0.0001 m2.K/W, respectively.
The properties of water evaluated at an average temperature at the average inlet and exit temperatures of 20ºC and 70ºC or 45ºC are

rho = 990.1kg/m^3
Cp= 4180J/kg.K
k= 0.637W/m.K
μ= 0. 596 ×10^-3 kg/m.s
Pr = 3.91

Calculate the mass flow rate of water.(Round the answer to three decimal places.)
Engineering
1 answer:
Olegator [25]2 years ago
4 0

Answer:

The mass flow rate of water is 1.21 kg/s

Explanation:

according to the conditions given in the exercise:

mhcp=4440 W/K

Th1=150°C

Th2=50°C

Tc1=20°C

Tc2=108°C

di=2 cm

do=2.25 cm

Di=6 cm

mh=2 kg/s

Rfo=0.00015 m^2K/W

Rfi=0.0001 m^2K/W

The properties of the water at 45°C are:

p=990.1 kg/m^3

Cp=4180 J/kgK

From the energy balance, we have:

mc*Cpc(Tc2-Tc1)=mh*Cph(Th1-Th2)

Clearing mc:

m_{c}=\frac{m_{h}C_{ph}(T_{h1}-T_{h2})    }{C_{pc}(Tc_{2}-Tc_{1}   }=\frac{4440(150-50)}{4180(108-20)} =1.21 kg/s

You might be interested in
Consider air entering a heated duct at P1 = 1 atm and T1 = 288 K. Ignore the effect of friction. Calculate the amount of heat pe
Ne4ueva [31]

Answer:

The solution for the given problem is done below.

Explanation:

M1 = 2.0

\frac{p1}{p*} = 0.3636

\frac{T1}{T*} = 0.5289

\frac{T01}{T0*} = 0.7934

Isentropic Flow Chart:  M1 = 2.0 , \frac{T01}{T1} = 1.8

T1 = \frac{1}{0.7934} (1.8)(288K) = 653.4 K.

In order to choke the flow at the exit (M2=1), the above T0* must be stagnation temperature at the exit.

At the inlet,

T02= \frac{T02}{T1}T1 = (1.8)(288K) = 518.4 K.

Q= Cp(T02-T01) = \frac{1.4(287 J / (Kg.K)}{1.4-1}(653.4-518.4)K = 135.7*10^{3} J/Kg.

5 0
2 years ago
Read 2 more answers
Which of the two materials (brittle vs. ductile) usually obtains the highest ultimate strength and why?
sveta [45]

Answer:

Explanation:

Ductile materials typically have a higher ultimate strength because they stretch absorbing more energy before breaking. While fragile materials snap in half before larger deformations due to larger loads occur.

It should be noted that when ductile materials stretch their section becomes smaller, and in that reduced section the stresses concentrate.

5 0
2 years ago
A 10-ft-long simply supported laminated wood beam consists of eight 1.5-in. by 6-in. planks glued together to form a section 6 i
ruslelena [56]

Answer:

point B where Q_B = 101.25 \ in^3  has the largest Q value at section a–a

Explanation:

The missing diagram that is suppose to be attached to this question can be found in the attached file below.

So from the given information ;we are to determine the  point that  has the largest Q value at section a–a

In order to do that; we will work hand in hand with the image attached below.

From the image attached ; we will realize that there are 8 blocks aligned on top on another in the R.H.S of the image with the total of 12 in; meaning that each block contains 1.5 in each.

We also have block partitioned into different point segments . i,e A,B,C, D

For point A ;

Let Q be the moment of the Area A;

SO ; Q_A = Area \times y_1

where ;

y_1 = (6 - \dfrac{1.5}{2})

y_1 = (6- 0.75)

y_1 = 5.25 \  in

Q_A =(L \times B)  \times y_1

Q_A =(6 \times 1.5)  \times 5.25

Q_A =47.25 \ in^3

For point B ;

Let Q be the moment of the Area B;

SO ; Q_B = Area \times y_2

where ;

y_2 = (6 - \dfrac{1.5 \times 3}{2})

y_2= (6 - \dfrac{4.5}{2}})

y_2 = (6 -2.25})

y_2 = 3.75 \ in

Q_B =(L \times B)  \times y_1

Q_B=(6 \times 4.5)  \times 3.75

Q_B = 101.25 \ in^3

For point C ;

Let Q be the moment of the Area C;

SO ; Q_C = Area \times y_3

where ;

y_3 = (6 - \dfrac{1.5 \times 2}{2})

y_3 = (6 - 1.5})

y_3= 4.5 \  in

Q_C =(L \times B)  \times y_1

Q_C =(6 \times 3)  \times 4.5

Q_C=81 \ in^3

For point D ;

Let Q be the moment of the Area D;

SO ; Q_D = Area \times y_4

since there is no area about point D

Area = 0

Q_D =0 \times y_4

Q_D = 0

Thus; from the foregoing ; point B where Q_B = 101.25 \ in^3  has the largest Q value at section a–a

3 0
2 years ago
Suppose that a wing component on an aircraft is fabricated from an aluminum alloy that has a plane-strain fracture toughness of
Orlov [11]

Answer: 133.88 MPa approximately 134 MPa

Explanation:

Given

Plane strains fracture toughness, k = 26 MPa

Stress at which fracture occurs, σ = 112 MPa

Maximum internal crack length, l = 8.6 mm = 8.6*10^-3 m

Critical internal crack length, l' = 6 mm = 6*10^-3 m

We know that

σ = K/(Y.√πa), where

112 MPa = 26 MPa / Y.√[3.142 * 8.6*10^-3)/2]

112 MPa = 26 MPa / Y.√(3.142 * 0.043)

112 = 26 / Y.√1.35*10^-2

112 = 26 / Y * 0.116

Y = 26 / 112 * 0.116

Y = 26 / 13

Y = 2

σ = K/(Y.√πa), using l'instead of l and, using Y as 2

σ = 26 / 2 * [√3.142 * (6*10^-3/2)]

σ = 26 / 2 * √(3.142 *3*10^-3)

σ = 26 / 2 * √0.009426

σ = 26 / 2 * 0.0971

σ = 26 / 0.1942

σ = 133.88 MPa

8 0
2 years ago
Fix the code so the program will run correctly for MAXCHEESE values of 0 to 20 (inclusive). Note that the value of MAXCHEESE is
GarryVolchara [31]

Answer:

Code fixed below using Java

Explanation:

<u>Error.java </u>

import java.util.Random;

public class Error {

   public static void main(String[] args) {

       final int MAXCHEESE = 10;

       String[] names = new String[MAXCHEESE];

       double[] prices = new double[MAXCHEESE];

       double[] amounts = new double[MAXCHEESE];

       // Three Special Cheeses

       names[0] = "Humboldt Fog";

       prices[0] = 25.00;

       names[1] = "Red Hawk";

       prices[1] = 40.50;

       names[2] = "Teleme";

       prices[2] = 17.25;

       System.out.println("We sell " + MAXCHEESE + " kind of Cheese:");

       System.out.println(names[0] + ": $" + prices[0] + " per pound");

       System.out.println(names[1] + ": $" + prices[1] + " per pound");

       System.out.println(names[2] + ": $" + prices[2] + " per pound");

       Random ranGen = new Random(100);

       // error at initialising i

       // i should be from 0 to MAXCHEESE value

       for (int i = 0; i < MAXCHEESE; i++) {

           names[i] = "Cheese Type " + (char) ('A' + i);

           prices[i] = ranGen.nextInt(1000) / 100.0;

           amounts[i] = 0;

           System.out.println(names[i] + ": $" + prices[i] + " per pound");

       }        

   }

}

7 0
2 years ago
Other questions:
  • 1. Create a class called Name that represents a person's name. The class should have fields named firstName representing the per
    8·2 answers
  • A heat pump is to be used to heat a house in winter and then reversed to cool the house in summer. The interior space is to be m
    13·2 answers
  • In this exercise, we will examine how replacement policies affect miss rate. Assume a two-way set associative cache with four on
    9·2 answers
  • The difference between ideal voltage source and the ideal current source​
    7·2 answers
  • A pitfall cited in Section 1.10 is expecting to improve the overall performance of a computer by improving only one aspect of th
    6·1 answer
  • Problem 8. Define a function gs1_error(n) that accepts as input a non-negative integer n and outputs the error of the Gauss-Seid
    7·1 answer
  • Two parallel surfaces move relative to each other are separated by a gap of 0.375 in. The gap is filled by a fluid of with .0043
    5·1 answer
  • A horizontal curve is to be designed for a two-lane road in mountainous terrain. The following data are known: Intersection angl
    7·1 answer
  • In C++ the declaration of floating point variables starts with the type name float or double, followed by the name of the variab
    15·1 answer
  • 1. A sine wave is to be used for two different signaling schemes: a. PSK b. QPSK The duration of a signal element is 10-5 s. If
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!