1answer.
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
Tema [17]
3 years ago
7

By efficiency, we generally mean the ratio of the desired output to the required input. That is, efficiency is a measure of what

is accomplished compared to what it costs. One important energy efficiency term for power conversion devices that operate in a cycle is thermal efficiency, ηth.
It is defined as the ratio of net work output (which is desired) to the heat input (which is costly).
Hence ካ = net work output/heat input. This definition of thermal efficiency leads to a value between zero and one.
A steam power plant generates 700,000 lbm/hr of steam in its boiler and has an output of 95,000 kW of power. The plant consumes 72,800 lbm/hr of coal, which has a "heating value" (the amount of thermal energy liberated when the coal is burned in air) of 13,000 Btu/lbm-coal.
a. Determine the overall plant thermal efficiency.
b. If the energy added to the steam from the combustion of coal in the steam-generating unit (the boiler) is 1140 Btu/lbm-steam, what fraction of the energy released from the coal is added to the steam? (This could be called the "boiler efficiency".
c. Energy transferred to the steam that doesn't result in power production (the 95 MW referred to above) has to be "discarded", often by using cooling water from a lake or river. Determine the amount of such heat rejection, in kW.
Engineering
1 answer:
natulia [17]3 years ago
6 0

Answer:

The answers to the question is as follows

a. 0.3425 or 34.25% efficiency

b. 0.8432 ≅ 0.84

c. 138,871 Kilowatts ≈ 140 kW

Explanation:

a.) Overall efficiency =η,overall = \frac{Heat equivalent of electric power}{Heat of coal cumbustion} i.e (heat amounting to the quantity of produced electric power) / (Heat produced by coal combustion)

The heat  equivalent of electric power → 95,000 kw ≡ 324,153,410 BTUs per Hour

heat produced by coal combustion =  72,800 ibm/hr which produces 13000 Btu/ibm-coal hence the amount of heat produced by the coal =

72,800 ibm/hr × 13,000 Btu/ibm-coal = 946400000 Btu/hr

Therefore overall plant efficiency = 324153410/946400000 = 0.3425

which is 34.25% efficiency

b.)  Energy added to the steam from combustion of coal = 1140 Btu/lbm-steam

Steam power plant generates = 700,000 lbm/hr

Energy added to the steam per hour from the coal = 700000×1140 = 798000000 Btu/hr,

Fraction of the energy released from the coal that is added to the steam =798000000/946400000 = 0.8432 of the energy released from the coal is added to the steam

c.) The amount of heat rejection is given by

Energy in steam - heat equivalent of energy of power output

798000000 Btu/hr -324,153,410 Btu/Hr = 473846590 Btu/Hr or 138,871 Kilowatts

You might be interested in
A vertical pole consisting of a circular tube of outer diameter 127 mm and inner diameter 115 mm is loaded by a linearly varying
Anna [14]

Maximum shear stress in the pole is 0.

<u>Explanation:</u>

Given-

Outer diameter = 127 mm

Outer radius,r_{2} = 127/2 = 63.5 mm

Inner diameter = 115 mm

Inner radius, r_{1} = 115/2 = 57.5 mm

Force, q = 0

Maximum shear stress, τmax = ?

 τmax  = \frac{4q}{3\pi } (\frac{r2^2 + r2r1 + r1^2}{r2^4 - r1^4} )

If force, q is 0 then τmax is also equal to 0.

Therefore, maximum shear stress in the pole is 0.

3 0
3 years ago
As cylinder pressure and heat increase due to an increased load condition, the fuel injection management system must ___________
Temka [501]

possible Answers:

Compensate ⭐⭐⭐⭐⭐

Adjust            ⭐⭐⭐⭐⭐

regulate         ⭐⭐⭐⭐

tune               ⭐⭐⭐

calibrate        ⭐⭐⭐

balance         ⭐⭐

correct           ⭐

6 0
2 years ago
g For this project you are required to perform Matrix operations (Addition, Subtraction and Multiplication). For each of the ope
Kruka [31]

Answer:

C++ code is explained below

Explanation:

#include<iostream>

using namespace std;

//Function Declarations

void add();

void sub();

void mul();

//Main Code Displays Menu And Take User Input

int main()

{

  int choice;

  cout << "\nMenu";

  cout << "\nChoice 1:addition";

  cout << "\nChoice 2:subtraction";

  cout << "\nChoice 3:multiplication";

  cout << "\nChoice 0:exit";

 

  cout << "\n\nEnter your choice: ";

 

  cin >> choice;

 

  cout << "\n";

 

  switch(choice)

  {

      case 1: add();

              break;

             

      case 2: sub();

              break;

             

      case 3: mul();

              break;

     

      case 0: cout << "Exited";

              exit(1);

     

      default: cout << "Invalid";      

  }

  main();  

}

//Addition Of Matrix

void add()

{

  int rows1,cols1,i,j,rows2,cols2;

 

  cout << "\nmatrix1 # of rows: ";

  cin >> rows1;

 

  cout << "\nmatrix1 # of columns: ";

  cin >> cols1;

 

   int m1[rows1][cols1];

 

  //Taking First Matrix

  for(i=0;i<rows1;i++)

      for(j=0;j<cols1;j++)

      {

          cout << "\nEnter element (" << i << "," << j << "): ";

          cin >> m1[i][j];

          cout << "\n";

      }

  //Printing 1st Matrix

  for(i=0;i<rows1;i++)

  {

      for(j=0;j<cols1;j++)

          cout << m1[i][j] << " ";

      cout << "\n";

  }

     

  cout << "\nmatrix2 # of rows: ";

  cin >> rows2;

 

  cout << "\nmatrix2 # of columns: ";

  cin >> cols2;

 

  int m2[rows2][cols2];

  //Taking Second Matrix

  for(i=0;i<rows2;i++)

      for(j=0;j<cols2;j++)

      {

          cout << "\nEnter element (" << i << "," << j << "): ";

          cin >> m2[i][j];

          cout << "\n";

      }

  //Displaying second Matrix

  cout << "\n";

  for(i=0;i<rows2;i++)

  {

      for(j=0;j<cols2;j++)

          cout << m2[i][j] << " ";

      cout << "\n";

  }

  //Displaying Sum of m1 & m2

  if(rows1 == rows2 && cols1 == cols2)

  {

      cout << "\n";

      for(i=0;i<rows1;i++)

      {

          for(j=0;j<cols1;j++)

              cout << m1[i][j]+m2[i][j] << " ";

          cout << "\n";  

      }

  }

  else

      cout << "operation is not supported";

     

  main();

 

}

void sub()

{

  int rows1,cols1,i,j,k,rows2,cols2;

  cout << "\nmatrix1 # of rows: ";

  cin >> rows1;

 

  cout << "\nmatrix1 # of columns: ";

  cin >> cols1;

 

   int m1[rows1][cols1];

 

  for(i=0;i<rows1;i++)

      for(j=0;j<cols1;j++)

      {

          cout << "\nEnter element (" << i << "," << j << "): ";

          cin >> m1[i][j];

          cout << "\n";

      }

 

  for(i=0;i<rows1;i++)

  {

      for(j=0;j<cols1;j++)

          cout << m1[i][j] << " ";

      cout << "\n";

  }

     

  cout << "\nmatrix2 # of rows: ";

  cin >> rows2;

 

  cout << "\nmatrix2 # of columns: ";

  cin >> cols2;

 

  int m2[rows2][cols2];

 

  for(i=0;i<rows2;i++)

      for(j=0;j<cols2;j++)

      {

          cout << "\nEnter element (" << i << "," << j << "): ";

          cin >> m2[i][j];

          cout << "\n";

      }

 

  for(i=0;i<rows2;i++)

  {

      for(j=0;j<cols2;j++)

          cout << m1[i][j] << " ";

      cout << "\n";

  }

  cout << "\n";

  //Displaying Subtraction of m1 & m2

  if(rows1 == rows2 && cols1 == cols2)

  {

      for(i=0;i<rows1;i++)

      {

          for(j=0;j<cols1;j++)

              cout << m1[i][j]-m2[i][j] << " ";

          cout << "\n";  

      }

  }

  else

      cout << "operation is not supported";

     

  main();

 

}

void mul()

{

  int rows1,cols1,i,j,k,rows2,cols2,mul[10][10];

  cout << "\nmatrix1 # of rows: ";

  cin >> rows1;

 

  cout << "\nmatrix1 # of columns: ";

  cin >> cols1;

 

   int m1[rows1][cols1];

 

  for(i=0;i<rows1;i++)

      for(j=0;j<cols1;j++)

      {

          cout << "\nEnter element (" << i << "," << j << "): ";

          cin >> m1[i][j];

          cout << "\n";

      }

  cout << "\n";

  for(i=0;i<rows1;i++)

  {

      for(j=0;j<cols1;j++)

          cout << m1[i][j] << " ";

      cout << "\n";

  }

     

  cout << "\nmatrix2 # of rows: ";

  cin >> rows2;

 

  cout << "\nmatrix2 # of columns: ";

  cin >> cols2;

 

  int m2[rows2][cols2];

 

  for(i=0;i<rows2;i++)

      for(j=0;j<cols2;j++)

      {

          cout << "\nEnter element (" << i << "," << j << "): ";

          cin >> m2[i][j];

          cout << "\n";

      }

  cout << "\n";

  //Displaying Matrix 2

  for(i=0;i<rows2;i++)

  {

      for(j=0;j<cols2;j++)

          cout << m2[i][j] << " ";

      cout << "\n";

  }

     

  if(cols1!=rows2)

      cout << "operation is not supported";

  else

  {

      //Initializing results as 0

      for(i = 0; i < rows1; ++i)

  for(j = 0; j < cols2; ++j)

  mul[i][j]=0;

// Multiplying matrix m1 and m2 and storing in array mul.

  for(i = 0; i < rows1; i++)

  for(j = 0; j < cols2; j++)

  for(k = 0; k < cols1; k++)

  mul[i][j] += m1[i][k] * m2[k][j];

// Displaying the result.

  cout << "\n";

  for(i = 0; i < rows1; ++i)

      for(j = 0; j < cols2; ++j)

      {

      cout << " " << mul[i][j];

      if(j == cols2-1)

      cout << endl;

      }

      }  

  main();

 }

5 0
3 years ago
Who can use NIST resources?
sukhopar [10]

Answer:

Federal agencies

Explanation:

NIST (National Institute of Standards and Technology) also called between 1901 and 1988 National Bureau of Standards (NBS), it is an agency of the Technology Administration of the United States Department of Commerce. The mission of this institute is to promote innovation and industrial competition in the United States through advances in metrology, standards and technology in ways that improve economic stability and quality of life.

As part of this mission, NIST scientists and engineers continually refine the science of measurement (metrology) by creating precise engineering and manufacturing required for most current technological advances. They are also directly involved in the development and testing of standards made by the private sector and government agencies. The NIST was originally called the National Bureau of Standards (NBS), a name it had from 1901 to 1988. The progress and technological innovation of the United States depends on the abilities of the NIST, especially if we talk about four areas: biotechnology , nanotechnology, information technologies and advanced manufacturing.

7 0
3 years ago
What’s the difference between quality and quantity
Lesechka [4]
Quality is how good something is. Like how good the material is. Like the quality of the IPhone X is better than the quality of the iPhone 6s + because it has more features and can sustain better hold
Quantity is how much. Like the quantity of the m&ms were split evenly.
I dont know exactly if that makes sense but there ya go
YW!
4 0
3 years ago
Read 2 more answers
Other questions:
  • Block A has a weight of 8 lb. and block B has a weight of 6 lb. They rest on a surface for which the coefficient of kinetic fric
    8·1 answer
  • You will create three classes, the first two being Student and LineAtOfficeHour. The instances of the first class defines a sing
    8·1 answer
  • The Danish scientist Niels Bohr proposed a model of the atom that is not totally accurate today but still contains components th
    12·1 answer
  • How to design a solar panel<br>​
    7·1 answer
  • Give me uses of a grinding machine in agriculture.
    15·1 answer
  • 2. What is the most obvious elements of design?<br> O color<br> O shape<br> O line<br> O texture
    11·1 answer
  • A driver is traveling at 90 km/h down a 3% grade on good, wet pavement. An accident
    11·1 answer
  • A new approval process is being adapted by Ursa Major Solar. After an opportunity has been approved, the contract is sent to the
    9·1 answer
  • A batch of 1000 is split into 10 smaller batches of equal size 100. The processing time of each unit is 2
    12·1 answer
  • An earth fill, when compacted will occupy a net volume of 187,000 cy. The borrow material that will be used to construct this fi
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!