题目内容
With a view to improving hybrid performance, you can use composite materials to reduce weight.
查看答案
搜索结果不匹配？点我反馈
更多问题
A．On the 6th of December.B．On the 7th of December.C．On the 26th of December.D．On the 2
Hybrid Cars
Have you pulled your car up to the gas pump lately and been shocked by the high price of gasoline？ As the pump clicked past $20 or $30, maybe you thought about trading in your car for something that gets better mileage. Or maybe you're worried that your car is contributing to the greenhouse effect.
The auto industry has the technology to address these concerns. It's the hybrid car. You're probably aware of hybrid cars because they've been in the news a lot. Most automobile manufacturers have announced plans to manufacture their own versions. What makes it a "Hybrid"？
Any vehicle is a hybrid when it combines two or more sources of power. In fact, many people have probably owned a hybrid vehicle at some point. For example, a moped (a motorized pedal bike) is a type of hybrid because it combines the power of a gasoline engine with the pedal power of its rider.
Hybrid vehicles are all around us. Most of the locomotives we see pulling trains are diesel-electric hybrids. Cities like Seattle have diesel-electric(以柴油发动机发电的) buses—these can draw electric power from overhead wires or run on diesel when they are away from the wires. Giant mining trucks are often diesel-electric hybrids. Submarines are also hybrid vehicles — some are nuclear-electric and some are diesel-electric. The gasoline-electric hybrid car is a cross between a gasoline-powered car and an electric car.
Hybrid Structure
You can combine the two power sources found in a hybrid car in different ways. One way, known as a parallel hybrid, has a fuel tank, which supplies gasoline to the engine. But it also has a set of batteries that supplies power to an electric motor. Both the engine and the electric motor can turn the transmission at the same time, and the transmission then turns the wheels.
By contrast, in a series hybrid the gasoline engine turns a generator, and the generator can either charge the batteries or power an electric motor that drives the transmission. Thus, the gasoline engine never directly powers the vehicle.
Why Build Such a Complex Car？
You might wonder why anyone would build such a complicated machine when most people are perfectly happy with their gasoline-powered cars. The reason is twofold: to reduce tailpipe emissions and to improve mileage. These goals are actually tightly interwoven.
Evolution of the Hybrid
The hybrid is a compromise. It attempts to significantly increase the mileage and reduce the emissions of a gas-powered car while overcoming the shortcomings of an electric car.
The Problem with Gas-powered Cars
To be useful to you or me, a car must meet certain minimum requirements. The car should be able to:
-Drive at least 300 miles (482 km) between re-fueling
-Be refueled quickly and easily
-Keep up with the other traffic on the road
A gasoline car meets these requirements but produces a relatively large amount of pollution and generally gets poor gas mileage. An electric car, on the other hand, produces almost no pollution, but it can only go 50 to 100 miles (80 to 161 km) between charges. And the problem has been that it is very slow and inconvenient to recharge.
A driver's desire for quick acceleration causes our cars to be much less efficient than they could be. You may have noticed that a car with a less powerful engine gets better gas mileage than an identical car with a more powerful engine. Just look at the window stickers(有图形或文字的粘贴标鉴) on new cars at a dealership for a city and highway mph comparison.
The amazing thing is that most of what we require a car to do uses only a small percentage of its horsepower! When you are driving along the freeway at 60 mph (96.6 kph), your car engine has to provide the power to do three things:
&
In most cases, what we require a car to do uses only a small percentage of its' horse power.
The series hybrid vehicle is sometimes directly powered by the gasoline engine.
微信支付 
支付宝支付