- #1
tumor
- 126
- 1
Why don't car makers produce cars with diesel engines coupled with electric generator and then use only electric motors for propulsion?
You know what I mean?
You know what I mean?
An electric motor alone has to be pretty big to accelerate a car: that's why a hybrid uses both a gas/diesel engine and an electric motor at the same time.tumor said:Why don't car makers produce cars with diesel engines coupled with electric generator and then use only electric motors for propulsion?
You know what I mean?
russ_watters said:An electric motor alone has to be pretty big to accelerate a car: that's why a hybrid uses both a gas/diesel engine and an electric motor at the same time.
When cruising, the diesel is preferable since its more efficient to use it directly than to use it to generate electricity.
This is true, but railway locomotives still use the diesel to drive a generator, and then use the generated electicity to drive the wheels. Why? It's because of the enormous engineering difficulty of driving many wheels, at all speeds from zero up to the locomotive's maximum.russ_watters said:When cruising, the diesel is preferable since its more efficient to use it directly than to use it to generate electricity.
This was my basic point. There are, of course exceptions such as diesel locomotives, where low-speed torque is critical.LunchBox said:Additionally, the loss of energy...
It's much more economical to convert chemical energy in the fuel to mechanical energy in an engine to the wheels than to convert chemical in the fuel to mechanical in the engine to electrical in the generator to mechanical in the motor to the wheels. Small losses at each step add up quick...
95% is about the limit of an electric motor on its own. I'm not sure about generators, but I doubt they are as efficient as motors - and using the same motor as a generator and a propulsor also likely reduces it. Last, excess energy needs to be stored in batteries for acceleration - an additional 95% on both sides of that.The mechanical-electric-mechanical conversion can be 95+% efficient...
Give them time! Currently, the "hybrid electric" cars (like the Toyota Prius) use the principle, but with gasoline engines. The big advantage of the design is that you can use a fairly small, efficient IC engine, and get the required extra power for accelerating from the electric motor. Most cars have big engines which are required to put out full power only a very small percentage of the time. By the way, most railroad locomotives are diesel-electric hybrids.tumor said:Why don't car makers produce cars with diesel engines coupled with electric generator and then use only electric motors for propulsion?
You know what I mean?
Gasoline engines are more commonly used in cars because they are simpler and less expensive to produce. They also have a wider range of speeds and can accelerate more quickly, making them more suitable for the varying speeds required in driving.
There are several advantages to using diesel-electric motors in cars. They are more fuel-efficient, have lower emissions, and can provide more torque at lower speeds. Additionally, diesel fuel is typically less expensive than gasoline, making it a more cost-effective option in the long run.
While there are some diesel-electric hybrid cars on the market, they are not as common as gasoline-electric hybrids. This is because diesel engines are heavier and more expensive to produce, which can make the overall cost of the vehicle higher. Additionally, diesel engines are not as well-suited for stop-and-go city driving, which is where the benefits of hybrid technology are most apparent.
Diesel-electric motors can be used in most types of cars, but they are most commonly found in larger vehicles such as buses, trucks, and trains. This is because these vehicles require more torque and can benefit from the fuel efficiency of diesel engines. However, with advancements in technology, we may see more diesel-electric motors being used in smaller cars in the future.
While diesel-electric motors can be more fuel-efficient and emit fewer emissions than gasoline engines, they still produce pollutants such as nitrogen oxides and particulate matter. However, advancements in diesel engine technology, such as the use of particulate filters, have helped to reduce these emissions. Additionally, the use of renewable diesel fuel can further decrease the environmental impact of diesel engines.