Why 100 efficiency is impossible?
It is impossible for heat engines to achieve 100% thermal efficiency () according to the Second law of thermodynamics. This is impossible because some waste heat is always produced produced in a heat engine, shown in Figure 1 by the term.
Which engine is most efficient?
Wärtsilä 31SG
Which is the most efficient cycle?
Carnot Cycle
Why can a Carnot engine not get 100% efficiency?
Even Carnot engine cannot give 100% efficiency because. In order to achieve 100% efficiency (η=1), Q2 must be equal to 0 which means that all the heat form the source is converted to work. The temperature of sink means a negative temperature on the absolute scale at which the temperature is greater than unity.
What is max efficiency of Carnot cycle?
From the Carnot Efficiency formula, it can be inferred that a maximum of 64% of the fuel energy can go to generation. To make the Carnot efficiency as high as possible, either Thot should be increased or Tcold (temperature of heat rejection) should be decreased.
Which statement is incorrect all reversible cycles have same efficiency?
All reversible engines work for different values of temperature of source and sink hence the efficients of all such engines are different. The incorrect statement is all reversible cycles have same efficiency.
Which statement is incorrect All reversible?
Is Carnot cycle reversible?
The Carnot heat-engine cycle described is a totally reversible cycle. That is all the processes that compose it can be reversed, in which case it becomes the Carnot refrigeration cycle.
Does all reversible cycles have same efficiency?
So all reversible cycle processes acting between two heat reservoirs must have the same efficiency which proves statement 1. We now can calculate the efficiency for any reversible cycle process to find the general result, and this will of course be the Carnot cycle.
Which thermodynamic cycle has maximum efficiency?
Carnot cycle
Do irreversible engines have maximum efficiency?
All the reversible and irreversible engines have the same efficiency. Irreversible engines have maximum efficiency. All engines are designed as reversible in order to obtain maximum efficiency.
What is the greatest possible value for thermal efficiency?
When expressed as a percentage, the thermal efficiency must be between 0% and 100%. Efficiency is typically less than 100% because there are inefficiencies such as friction and heat loss that convert the energy into alternative forms.
Why thermal efficiency of 4 stroke engine is more than 2 stroke engine?
As far as efficiency goes, the 4-stroke certainly wins. This is due to the fact that fuel is consumed once every 4 strokes. Four-stroke engines are heavier; they weigh upwards of 50% more than a comparable 2stroke engine.
Why are heat engines so terribly inefficient?
But yes, heat engines are generally quite inefficient. Ultimately, it’s because heat itself is a fairly inaccessible form of energy. Doing that removes energy from the gas so it cools and loses pressure. By repeating the compression of a hot gas and extracting energy using a piston, we can get continuous work.
Can a system ever be 100% efficient?
No machine is free from the effects of gravity, and even with wonderful lubrication, friction always exists. The energy a machine produces is always less than the energy put into it (energy input). That is why 100% efficiency in machines shall not be possible.
Is it possible to have a 100% efficient machine?
In other words, no machine can be more than 100% efficient. Machines cannot multiply energy or work input. If a machine were 100% efficient then it can’t have any energy losses to friction, so no friction can be present.
What is the most efficient energy conversion?
Example of energy conversion efficiency
| Conversion process | Conversion type | Energy efficiency |
|---|---|---|
| Solar cell | Radiative to electrical | 6–40% (technology-dependent, 15-20% most often, 85–90% theoretical limit) |
| Fuel cell | Chemical to electrical | up to 85% |
| World Electricity generation 2008 | Gross output 39% | Net output 33% |
| Electricity storage | ||
Are most energy transformations 100% efficient?
It’s fairly clear you mean efficiency as in the conversion of energy to whatever useful form is required. Otherwise the answer, trivially, is that all energy transitions are 100% efficient (if you include mass as a form of energy via E=mc^2).
Which energy has the lowest efficiency?
coal
What happens during a typical energy conversion?
Energy transformation, also known as energy conversion, is the process of changing energy from one form to another. For example, to heat a home, the furnace burns fuel, whose chemical potential energy is converted into thermal energy, which is then transferred to the home’s air to raise its temperature.
What is an example of energy conversion?
Energy can be converted from one form to another. Examples: Gasoline (chemical) is put into our cars, and with the help of electrical energy from a battery, provides mechanical (kinetic) energy. Similarly, purchased electricity goes into an electric bulb and is converted to visible light and heat energy.
Why didn’t the bowling ball pendulum hit Bill Nye in the face?
Why didn’t the bowling ball pendulum hit Bill Nye in the Face? Because kinetic energy will never be more than potential energy. This is done when a force (a push or a pull) acts on something for a distance.