Download presentation

Presentation is loading. Please wait.

1
Thermo & Stat Mech - Spring 2006 Class 5 1 Thermodynamics and Statistical Mechanics Heat Engines and Refrigerators

2
Thermo & Stat Mech - Spring 2006 Class 52 Carnot Cycle A Carnot cycle is an idealized reversible cycle that operates between two heat reservoirs at temperatures T 1 and T 2, where T 2 > T 1. It can operate as a heat engine, or a refrigerator.

3
Thermo & Stat Mech - Spring 2006 Class 53 Carnot Cycle

4
Thermo & Stat Mech - Spring 2006 Class 54 Carnot Cycle (Heat Engine)

5
Thermo & Stat Mech - Spring 2006 Class 55 Carnot Cycle

6
Thermo & Stat Mech - Spring 2006 Class 56 Carnot Cycle For the entire cycle, Q = W + U, and U = 0. The total heat equals the total work, Q = W. |W| = |Q 2 | – |Q 1 | Conservation of energy. |Q 2 | = |Q 1 | + |W|

7
Thermo & Stat Mech - Spring 2006 Class 57 Carnot Cycle For an isothermal process: For an adiabatic process:

8
Thermo & Stat Mech - Spring 2006 Class 58 Path a b

9
Thermo & Stat Mech - Spring 2006 Class 59 Paths b c, c d, and d a

10
Thermo & Stat Mech - Spring 2006 Class 510 Carnot Cycle Divide a b by c d and then b c by d a, and

11
Thermo & Stat Mech - Spring 2006 Class 511 Thermal Efficiency ( ) If T 1 = 0, = 1 (100%)

12
Thermo & Stat Mech - Spring 2006 Class 512 Refrigerator (Heat Pump) Run the cycle in reverse. Do work |W| on the system, remove |Q 1 | from the low temperature reservoir, and put |Q 2 | into the high temperature reservoir. As in a heat engine, |Q 2 | = |Q 1 | + |W|.

13
Thermo & Stat Mech - Spring 2006 Class 513 Coefficient of Performance (for Refrigerator)

14
Thermo & Stat Mech - Spring 2006 Class 514 Coefficient of Performance (for Heat Pump)

15
Thermo & Stat Mech - Spring 2006 Class 515 Otto Cycle (Gasoline Engine)

16
Thermo & Stat Mech - Spring 2006 Class 516 Otto Cycle W = |Q 2 | – |Q 1 | |Q 2 | = C V (T c – T b ) |Q 1 | = C V (T d – T a )

17
Thermo & Stat Mech - Spring 2006 Class 517 Otto Cycle

18
Thermo & Stat Mech - Spring 2006 Class 518 Otto Cycle and Subtract, and get, Then,

19
Thermo & Stat Mech - Spring 2006 Class 519 Otto Cycle is called the compression ratio.

20
Thermo & Stat Mech - Spring 2006 Class 520 Diesel Cycle

Similar presentations

© 2021 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google