Table of Contents
- 1 Which has more efficiency Otto cycle or Diesel cycle?
- 2 Why is the ideal Diesel cycle more efficient than the Otto cycle?
- 3 How is thermal efficiency of Otto cycle calculated?
- 4 Why diesel engine has higher thermal efficiency?
- 5 What is the efficiency of a diesel engine?
- 6 What is the efficiency of diesel cycle?
Which has more efficiency Otto cycle or Diesel cycle?
Although for a given compression ratio the Otto cycle has higher efficiency, because the Diesel engine can be operated to higher compression ratio, the engine can actually have higher efficiency than an Otto cycle when both are operated at compression ratios that might be achieved in practice.
Why is the ideal Diesel cycle more efficient than the Otto cycle?
The simple answer is ,In the otto the energy available is fully used to raise the pressure in the cylinder. Higher the pressure implies larger work done. But in diesel cycle, Part of the energy is added only during the expansion, So it does not contribute to the work. Hence Otto cycle is more efficient.
Why does the diesel engine have a better efficiency compared to an Otto engine in general?
Most petrol (gasoline, Otto cycle) and diesel (Diesel cycle) engines have an expansion ratio equal to the compression ratio. The thermal and gas dynamic losses from the prechamber result in direct injection diesels (despite their lower compression / expansion ratio) being more efficient.
What is the difference between Otto cycle and Diesel cycle?
The Otto cycle has less compression ratio (7:1 to 10:1) but in diesel cycle the compression ratio is high (11:1 to 22:1). In Otto cycle as well as in diesel cycle heat rejection takes place at constant volume. The efficiency of Otto cycle is less as compared with the Diesel cycle.
How is thermal efficiency of Otto cycle calculated?
In this equation, the ratio V1/V2 is known as the compression ratio, CR. When we rewrite the expression for thermal efficiency using the compression ratio, we conclude the air-standard Otto cycle thermal efficiency is a function of compression ratio and κ = cp/cv.
Why diesel engine has higher thermal efficiency?
Because diesel has a higher compression resistance — because it is denser than light distillate fuels — engineers can design and develop diesel engines with higher compression ratios than gasoline engines. The higher the compression ratio of an engine, the greater the thermal efficiency.
How efficient are diesel engines?
Diesel engines have a high efficiency (up to 45\%) in power generation and can also be adapted to combined heat and power systems (CHP).
What is the efficiency of Diesel cycle?
A typical diesel automotive engine operates at around 30\% to 35\% of thermal efficiency. About 65-70\% is rejected as waste heat without being converted into useful work, i.e., work delivered to wheels. In general, engines using the Diesel cycle are usually more efficient than engines using the Otto cycle.
What is the efficiency of a diesel engine?
between 55-60\%
What is the maximum efficiency an engine can achieve? The diesel engine has a theoretical system efficiency of between 55-60\%. For reference, the best power stations operate at 50-55\% efficiency, and fuel cells are also around 50\%+ efficient – so diesel engines can be incredible efficient.