What Is Heat Engine? | An-Overview

This article describes a heat engine, which is a famous type of engine. In thermodynamics and technology, a heat engine is a device that changes thermal or heat power into mechanical power, which can use for performing different mechanical works. This is achieved by moving the work material from a higher temperature to a lower temperature.

External Combustion engine, heat engine

The heat source produces thermal energy that heats the working material and converts its temperature into high temperature. This working material produces work in the engine’s working body and at the same time transfers thermal energy to the cold fluid tank until it touches a state of required low temperature. In this procedure, some thermal power converts into work using the properties of the working material.

When someone rubs his hand one on the other hand, then friction produces due to rubbing. This friction converts mechanical energy (hand movements) into heat (hands become hotter). The heat engine works in opposite phenomena because this type of engine takes energy from warm energy (compared to the environment) and converts it into movement. Usually, this movement converts into electrical energy by a generator.

Heat engines use different working materials, but mostly, these engines use liquids or gas. In this procedure, a small part of the heat is generally lost to the environment, and this part of the heat can’t be transformed into the final output. In addition, some of the energy cannot be used due to drag and friction force.

Heat engines generate almost all types of energy that uses for electricity and transport. Almost all things, even gases, have heat energy that may convert into valuable energy. A heat engine transfers energy from a hot to a cold place and converts some energy into mechanical power. A temperature gap is required for the operation of the heat engine.

Heat engine

The first inspiration for thermodynamic research was the attempt to extract as much energy as possible from the heat engine. Numerous fuels such as uranium, coal, and gasoline, etc., have been used up so far. All of these heat engines are still operating under the constraints obliged by the second law of thermodynamics. It means that different working fuels have been utilized to heat the gas and require a large cooling tank to remove residual heat. So, the waste heat generated by this process usually ends up in the environment or large quantities of water such as river, lake, or sea.

According to the engine type, various methods are used, e.g., burning to ignite fuel (coal and gasoline) or using power from a nuclear process to generate heat (e.g., uranium), but the purpose of these processes is the same (converting heat into useful work). The most common examples of a heat engine are the engines of different vehicles, e.g., trucks, buses, cars, etc. Most hydropower plants such as nuclear, natural gas, coal, and hydroelectric power plants also have heat engines.

Types of Heat Engine:

There are two most famous types of heat engines.

  1. External Combustion Engine (ECE)
  2. Internal Combustion Engine (ICE)

The explanation of these engines is given below.

1) External Combustion Engine

An external combustion engine is a famous type of heat engine in which the working medium is ignited through combustion in an external source through the wall of the heat exchanger or engine. These engines don’t fit in the internal part of the vehicle like the IC engine. External combustion engine attaches to the external portion of the vehicle. In this engine, combustion does not take place in the cylinder, but the piston is driven through steam. It’s out to that place.

External combustion engine

The external combustion chamber has a mixture of air and fuel that ignites to generate heat. This generated heat is utilized to heat the inner fluid through the wall of the heat exchanger or the engine. When heated, the liquid expands and acts on the engine machinery to create movement and useful work. This fluid is then poured (open cycle) or cooled, compressed, and use again (closed circuit). External combustion engine uses combustion primarily as a medium of heat, and this engine operates equally well with other heat source types.

The steam engine is an example of an external combustion engine. Maximum part of the world electricity produces through steam turbines. In kilowatts, steam is still the best, even if it outperforms the internal combustion engine. One more example is the Stirling engine, which currently only plays a niche function. Particular types of gas turbines use external circulation. It can expand quickly to form supercritical carbon dioxide as an operating fluid.

The train having a steam engine is also a well-known example of an external combustion engine.


Working of EC Engine

An external combustion engine is a heat engine that transforms thermal energy into mechanical power by heating the circulating working medium by burning fuel.

A new type of EC engine uses hydrogen as the working medium (the energy transfer medium is known as a working medium) and fills four closed cylinders through a specific amount of the working medium. Cylinder’s one end uses as a cold chamber, and the other end uses as a hot chamber. The working medium compresses in the cold chamber and then quickly warmed and expanded in the hot chamber. External combustion engine prevents the conventional IC engines’ detonation issues, resulting in low operating costs, low pollution, and low noise levels.

EC engines can use a variety of flammable gases, including liquid fuel, diesel oil, hydrogen gas, petroleum gas, biogas, natural gas, and other liquefied petroleum gases.

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