Everyday examples of heat engine:)

1. Steam engine - a heat engine that performs mechanical work using steam as its working fluid. 

   Stationary applications

   Stationary steam engines can be classified into two main types:
   
   1. Winding engines, rolling mill engines, steam donkeys, marine engines.
   2. Engines providing power, which rarely stop and do not need to reverse. 

   Transport applications

   A steam locomotive- a GNR N2 Class No.1744 at Weybourne nr. Sheringham, Norfolk.
   Steam engines have been used to power a wide array of transport appliances.
                                                                                                                   
2. Diesel engine - also known as a compression-ignition engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber during the final stage of compression.             

   * Passenger cars

   

   diesel engine

   * Railroad rolling stock

   Diesel engines have eclipsed steam engines as the prime mover on all non-electrified railroads in the industrialized world. 

   * Other transport uses

   Larger transport applications (trucks, buses, etc.) also benefit from the diesel's reliability and high torque output.

   * Military fuel standardisation

   NATO has a single vehicle fuel policy and has selected diesel for this purpose. 
   
   
3.  Internal combustion engine - an engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber.

   

   automobile engine

   Applications:                      
                                                                                                                                                                                         Internal combustion engines are most commonly used for mobile propulsion in vehicles and portable machinery.                                                                                   
   
   
   Generally using fossil fuel (mainly petroleum), these engines have appeared in transport in almost all vehicles (automobiles, trucks, motorcycles, boats, and in a wide variety of aircraft and locomotives).
   
   
   Where very high power-to-weight ratios are required, internal combustion engines appear in the form of gas turbines. 
   
   
   
   

   
   

   Drinking birds  
   
   
   
     - also known as dippy birds and dipping birds
     - are toy heat engines that mimic the motions 
       of a bird drinking  from a fountain or other   
       water source
     - It is sometimes incorrectly considered a 
       perpetual motion device
                                                                                                           
      The drinking bird is a heat engine that exploits a temperature differential to convert heat energy to a pressure differential within the device, and perform mechanical work. Like all heat engines, the drinking bird works through a thermodynamic cycle. The initial state of the system is a bird with a wet head oriented vertically with an initial oscillation on its pivot.
   
   

   
   

   The process operates as follows:

   1. The water evaporates from the felt on the head.
   2. Evaporation lowers the temperature of the glass head (heat of vaporization).
   3. The temperature decrease causes some of the dichloromethane vapor in the head to condense.
   4. The lower temperature and condensation together cause the pressure to drop in the head (ideal gas law).
   5. The pressure differential between the head and base causes the liquid to be pushed up from the base.
   6. As liquid flows into the head, the bird becomes top heavy and tips over during its oscillations.
   7. When the bird tips over, the bottom end of the neck tube rises above the surface of the liquid.
   8. A bubble of vapor rises up the tube through this gap, displacing liquid as it goes.
   9. Liquid flows back to the bottom bulb (the toy is so designed that when it has tipped over the neck's tilt allows this), and vapor pressure equalizes between the top and bottom bulbs
   10. The weight of the liquid in the bottom bulb restores the bird to its vertical position
   11. The liquid in the bottom bulb is heated by ambient air, which is at a temperature slightly higher than the temperature of the bird's head.

   
   

   learn more:))