As a result, thermal efficiency was improved owing to the combined increase in injection pressure, advanced injection timing, and split-main injection. According to the analysis of heat balance, a larger amount of the second part of the main injection decreased the cooling loss and increased the exhaust loss.
How can you improve the thermal efficiency of an engine?
Lower compression ratios need higher degrees of constant volume to improve the thermal efficiency by cooling loss reductions. Therefore, a method that reduces cooling loss without lowering the degree of constant volume will be effective to improve the thermal efficiency of internal combustion engines.
How can I increase my diesel fuel efficiency?
12 Tips to Improve Diesel Fuel Mileage
- Turn your engine off. …
- Use shore power when you can. …
- Avoid revving the engine. …
- Find your engine’s sweet spot and run with it. …
- Use your air conditioner as sparingly as possible. …
- Anticipate upcoming traffic lights. …
- Maintain an extended following distance. …
- Lower your average highway speed.
What is thermal efficiency of diesel engine?
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.
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.
How can I improve the thermal efficiency of my house?
Ways to improve your home to make it energy efficient
- Reduce your heating or use a secondary heating source.
- Use a new, energy efficient boiler.
- Fit insulation.
- Double or triple glazing.
- Draught proofing.
- Generate your own energy from renewable sources.
- Energy efficient fittings.
Why efficiency of diesel engine is high?
Diesel is more dense than petrol and contains about 15% more energy by volume. … The higher compression ratio of the diesel engine means it has a high expansion ratio – the difference between the compressed space and the space opened up when the piston reaches the bottom of its travel. That equates to higher efficiency.
Why is my diesel truck getting bad mileage?
A bad fuel injector or dirty/old fuel filter can drastically affect the flow of fuel into the engine. A fuel system problem is one of the most common causes of poor gas mileage. The more you run your A/C, the lower gas mileage you will get.
Why is my diesel car using more fuel?
Faulty Engine/Engine Issues
A damaged engine cannot work properly and in turn, can consume more fuel. … For instance, a faulty spark plug or O2 sensor in a petrol engine and a dirty fuel injector in a diesel engine can cause more consumption of fuel resulting in low fuel mileage.
What is the most efficient diesel engine?
The new Wärtsilä 31 is the most fuel-efficient four-stroke engine currently available on the market. The diesel version of the engine consumes on average 8–10g/kWh less fuel compared with the closest competitor across its entire load range. At its optimum point this number can go as low as 165g/kWh.
What is the formula for thermal efficiency?
The thermal efficiency, ηth, represents the fraction of heat, QH, that is converted to work. The air-standard Otto cycle thermal efficiency is a function of compression ratio and κ = cp/cv. The thermal efficiency, ηth, represents the fraction of heat, QH, that is converted to work.
What are the 3 categories of engine efficiency?
Accordingly, the overall brake thermal efficiency of the engine is a product of the combustion, thermodynamic, gas exchange, and mechanical efficiency.
- Engine Energy Losses. Summary of Losses. Fuel Energy. Combustion Efficiency. Thermodynamic Efficiency. Heat Losses. …
- Efficiency from the Perspective of the Fuel.
Can a system be 100% efficient?
Because of conservation of energy EVERY system produces an equal amount of energy that’s put into the system. … So if you put in 100 watts of power and get 50 watts of light the system is 100% efficient. There is a principle called “unity efficiency” that can allow you to produce MORE than 100% of the input.
Are Carnot engines 100% efficient?
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.
Is there any real machine where its efficiency is 100% why?
Answer: In practice no machine can achieve 100% efficiency. When you mean 100% efficiency it means your input energy should be completely transformed to output energy. … Various mechanical and electrical losses like friction and eddy current losses are the reasons behind the energy dissipation.