A heat engine is a device that is quite popular to convert thermal energy into mechanical energy. A heat engine can be defined as a device that is used to convert heat or heating energy into mechanical energy to do the work. For example, jet engines use heat energy to convert it into mechanical energy, which thus does the work.
Heat engines are harmful to nature. That is why scientists focus on converting these engines into mechanical work. Heat energy is the result of global warming ( temperature difference ) and it is not good for the environment. The difference between hot and cold temperatures gives rise to heat engines. So, the study of heat engines is essential to understand how thermal energy is getting converted into mechanical energy to work and why this is important to understand.
WHAT IS A HEAT ENGINE
EXAMPLE OF A HEAT ENGINE WITH FIRING A PISTOL
Heat is energy. Energy is transferred from one body to another.
An engine is a system/machine which is used to convert energy into work.
So, heat engines are the devices that are used by engineers to convert thermal energy/heat into mechanical energy to perform the work. Heat engine devices take the heat from a reservoir and then do the work. For example, in the case of moving a pistol, an individual requires energy to shoot from a pistol. When a person clenches the pistol, it requires energy to do that and the same is the case when it happens when a bullet is fired from a pistol.
The heat engine is a study in thermodynamics. Most famously, steam engines. Now the concept of heat engines has expanded and it has improved efficiency.
CHARACTERISTICS OF HEAT ENGINE
Conversion of heat into work
Maximizing efficiency
Modern invention
Receiving heat from a high-temperature surface
They act as cyclic devices.
Heat engines are different from other engines
Fundamentally limited
New technology
Source of heat
In a loop shape
Uses a high-temperature source of heat energy
Leftover heat
Differences between heat engines one to another
Fluid friction
Types of Heat Engine
TYPES OF HEAT ENGINE
1) External combustion engine
The main idea of an external combustion engine is that the fuel burns outside or away from the main engine, which means coal is burning outside or is burning some distance away from the main engine part. This will decrease the chances of unhappening or being caught or fired. For example, in the case of a steam engine, on one hand, there is a coal fire that heats the water so that it will get converted into heat steam. This will eliminate all the chances of unhappening.
2) Internal combustion engine
This is the opposite of an external combustion engine as the main idea of an internal combustion engine is that the fuel burns inside of the main engine. For example, in a car engine there is more than one cylinder and in that gasoline is constantly burning to release heat energy.
To ensure that the engine produces a steady supply of power, it becomes important to have an internal combustion engine specifically in car engines. Apart from the dangerous sight of this engine, internal combustion engines are generally very efficient. The reason is that everything happens in the same place.
COMPONENTS of heat engine
Fixed elements: cylinder head, block
Moving elements: flywheel, connecting rod
Engine block- It is inside the cylinders. These serve as driving elements like pistons, which give support. They are made up of aluminum and alloy.
Engine cylinders- The important part of every block is the cylinders. Inside the cylinders, the piston moves from the upper center to the lower center. They are very extreme positions.
Engine cylinder head- The cylinder holds the purpose of a combustion chamber. They serve as a watertight cover for engine cylinder heads.
Sump- It is a position where the lubrication oil from the heat engine stays. They are made up of sheet steel, due to good thermal connectivity. One advantage of this is that this component reduces the noise of the motor.
Piston- A mobile type of element that moves inside of a cylinder. It acts as a connecting rod and is made up of two parts and they are the head and the skirt. It is made up of aluminum.
Segments- The function of segments is to ensure the tightness of the lubrication of the cylinder. Segments are of two types: the first one is compression and the second type is one.
White- White is a connecting rod that is used to transfer power, which mostly happens in the case of firing the pistol.
Crankshaft- A very important component that is used to collect the forces during the process where the conversion takes place.
Flywheel- The flywheel stores kinetic energy to make the process more smooth and also helps in energy.
WORKING OF HEAT ENGINE
In previous years, technology had not evolved and that is why people of that age face difficulties. But the world has now changed and so does technology. Today, life cannot be expected without technology because technology has evolved from steam engines to modern inventions and in the case of humans, they are using tools to multiply their muscle power.
Today no one walks to offices and schools on foot because of addiction to technology which gives support in the way of studying and working and that is the reason people today cannot live without cars, ships, planes, etc. These things are properly built like powerful engines.
From the past to the present, engines don’t just move around the world, they have just evolved over example, now bridges, dams, and buildings are being built with the help of engines like cranes, bulldozers, etc. Engines, being an important part of modern evolution have also evolved. The changes from time to time made them compatible with the environment.
And this is how the heat engine has been working from the past to the present.
ADVANTAGES OF HEAT ENGINE
Heat engines serve many advantages. Some of them include:
Many forms of energy can be easily converted. The most famous is combustion.
Even absorb light particles
Have friction
Renewable source
Performs on the same cycle repeatedly
Discovery of various new machines
Helps with regulating/keeping the temperature under control
Takes very little time to convert
The cost that is used for conversion is quite less.
Working with cycling procedures is much better than working with normal procedures
Temperatures work at a high pressure
Helps in abating the difference between hot reservoirs and low reservoir
Easy to dye garments
DISADVANTAGEs
A heat engine is a machine. So along with advantages, it also has some drawbacks. These include:
The very first disadvantage of a heat engine is that it has limited operating efficiency.
Resistance of energy
Inefficient in being able to adapt
Maintenance charges are quite high
Leakages are the main cause of failures
The pressure of converting energy
Distortion of heat substances
Problem with the added cost
Contamination of substances
Risk in doing this job
You can catch fires in this type of process
If one component/part gets damaged, automatically all other electrical components will get damaged
Produced harmful gasses
Excess heat can not be used in anything
Environmental harm
Very difficult to sustain
Low engine emissions
APPLICATION OF HEAT ENGINE
Application of Heat Engine
The application part is about how the heat engine operates in the real world. The cycle takes place in thermodynamics. The process takes place when the transferring of heat energy starts at a high temperature and ends at a low temperature. That means the result will take place when the heat energy transfers from a high temperature to a low temperature, keeping a certain amount of energy at the same time as will be used for the conversion.
From the picture above, you can see the diagram of the heat engine. Here the temperature of the reservoir and the temperature of the sink are given. The heat engine is absorbing the heat from the reservoir part and gives the heat in terms of energy to the sink part to work.
The idea behind it is to take the heat from a high temperature and give the heat in terms of energy to a low temperature so that it can complete the work. Here, the efficiency of the heat plays an important role.
CONCLUSION
In the end, the efficiency of an engine completely depends upon the maximum and minimum temperatures of an engine. Most of the greatest vehicles, like trucks, jet planes, rockets, etc. use and work at high temperatures because good and efficient engines can work on the greatest possible temperature differences. Because of that reason, the greatest vehicles use the higher temperature at the beginning of the cycle and try to lower the temperature at the end of the cycle to remain efficient as possible.
FAQ’S
QUES 1) What is the basic principle of a jet engine?
ANS - The basic principle is that they are the generation of forwarding motions with the help of high velocity. The fluid is generated from the combustion of fuel and air.
QUES 2) What are the essential requirements of a heat engine?
ANS - The essential requirements of heat engines are the source of heat at high temperatures and the sink of heat at a lower temperature.
QUES3) What is the maximum efficiency of a heat engine?
ANS - Heat engines can operate at 30-50% of their efficiency.
QUES 4) What is the main function of a heat engine?
ANS - A heat engine is used to extract heat from a particular substance and then convert it into mechanical work.