Converting heat to mechanical work

By Robert M. Hazen, PhD, George Mason University

The second law of thermodynamics sets limits on how energy is transferred from one form to another. Heat flows from hot to cold. Similarly, converting heat into an engine cannot be performed 100% efficiently because some of the heat must escape to the environment and some must be used to regenerate the engine.

Steam engine image on white background.
Nicholas Carnot’s efficiency formula is now used to calculate the efficiency of any engine. (Image: Martin Shutterstock)

Analog of water wheel and steam engine

An example can be drawn between the gravitational force of gravity and the force of gravity on a water wheel. Heat is a more subtle concept, but water can be held by hand. So, think of designing a water wheel as effectively as possible. The water level above the sea level is similar to the temperature of the fuel, and the level below the water wheel is similar to the temperature at which the water flows. In this design, the sea level is considered to be zero energy or absolute zero.

First, some water is leaking, inhaled into the air, or it may penetrate the material used to make the wheel. The water pump is designed to reduce steam levels, reduce water loss and leakage by carefully sealing all cracks. But still, little water is lost, and there is no way around it.

Image of a water wheel in a village
An example can be drawn between the gravitational force of gravity and the force of gravity on a water wheel. (Image: IMG Stock Studio / Shutterstock)

Second, some of the force must be used to turn the wheel. Therefore, some water can only be used to raise the buckets.

The water wheel can be made of lightweight materials and high-quality lubricants to soften the wheel, but there is always some water loss when the wheel rotates. And this loss is like the force used to pull a steam engine piston backwards.

However, no matter how carefully designed, some of the potential of the water is always wasted, because the water cycle is always above the surface, and its effectiveness is limited. That was the inner loss that Nicholas Carnot knew.

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Mathematical law for high efficiency

Carnath’s greatest contribution was to develop the right mathematical law that would set the maximum efficiency for any engine. That is, the percentage of heat energy that can be used to perform a task, always the percentage of waste (due to design considerations). The maximum efficiency of any engine is based on two easily measurable figures.

First, there is the “T” for the thermal peak (the heat energy flowing into the system to work). And at the other end of the system, there is a cooler called TTld. That is the heat from the engine, the exhaust. Each generator has the same exhaust, and the heat of that exhaust.

Like a water wheel, a mechanical device mounted between a high-gravity and a low-gravity device is only a mechanical device installed between a motor tank and a cold tank.

Efficiency and then the difference between these two temperatures, the difference between toot and tocold, divided by the temperature of the heat storage can be expressed mathematically.

It should be a hundred times more than a hundred. The following formula is used to calculate the maximum efficiency of all types of efficiency, for various generators, motors, and so on. This is very important to understand the potential benefits of modern engines.

E = 1-TCold / THot × 100

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Turning heat into work in today’s society

A picture of a man with coal in his hands.
Fuel is rated according to the heat produced. (Image: Shutterstock),

In the days of Carnot, before these principles were understood, the efficiency of conventional steam engines was only six percent. But when people look at the logic of carnation, they realize that they can achieve great things. So they began to design improvements, better insulation, better materials, narrow-fitting steam pipes, and so on. And today the efficiency of these improvements has increased by about 40 percent, for example in coal-fired power plants.

That is 90 percent closer to the theoretical limit, so it is very close to the maximum theoretical potential of coal-fired power plants. Here is a clear indication of the fact that theories and perceptions of power are being used more efficiently today and have brought amazing benefits to society.

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Types of fuels depending on the temperature they hold

Fuel can be rated according to the temperature. Carnot’s explanation, for example, shows why some highly combustible fuels, such as coal, gas, and oil, are all highly regarded. This is because they burn at such a high temperature, and therefore you can make plants more efficient. About 90 percent of the world’s industrialized energy is from fossil fuels.

In some places it is still possible to scrape coal and dig deep wells, so for the time being these fossil fuels are very valuable and play an important role in the world’s energy supply. These fossil fuels represent ancient forms of life buried and transformed into earth’s heat and warmth. They are limited resources.

Common questions about converting heat into mechanical work

Q: Why are fossil fuels more valuable than other fossil fuels?

When fossil fuels burn, they reach higher temperatures than other fuels. Therefore, more Converting heat to work It happens.

Q: According to Nicholas Carnot, what is the internal loss?

Increase Of Converting heat to work In any engine, Nicholas Carnot realized that they should be well-designed with light weight pistons, good lubrication, better coverage, and so on. He realizes that no matter how well the engines are designed, there is always a lack of power in the system.

Q: What was Nicholas Carrot’s fitness formula?

Nicholas Carnot found a formula for calculating the efficiency of any engine. In this formula, the difference between the hot and cold ends is divided by the temperature of the hot storage tank. better than Of Converting heat to work, The higher the engine efficiency.

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