Because there is no reason to use gasoline.

汽油機(jī)效率低，同樣質(zhì)量的汽油（用汽油機(jī)）發(fā)的電少于同樣質(zhì)量的柴油（用柴油機(jī)）汽油價(jià)格高，同樣體積的汽油價(jià)格高于柴油汽油密度低，同樣質(zhì)量的汽油體積略微大于柴油，這點(diǎn)加重了上面這點(diǎn)。柴油易燃，一般大氣壓下柴油是220度，汽油是427度。

The efficiency of gasoline engine is low. The power generated by gasoline of the same quality (using gasoline engine) is less than that of diesel of the same quality (using diesel engine). The price of gasoline of the same volume is higher than that of diesel. The density of gasoline is low. The volume of gasoline of the same quality is slightly larger than that of diesel, which aggravates the above point. Diesel fuel is flammable. Under general atmospheric pressure, diesel fuel is 220 degrees and gasoline is 427 degrees.

當(dāng)然，實(shí)際上都是高壓下燃燒。柴油是并且柴油機(jī)是壓燃，導(dǎo)致機(jī)器的允許工作范圍大，不會(huì)爆震，不容易熄火（在高溫下柴油機(jī)甚至可以燒汽油）汽油點(diǎn)火能量低，易揮發(fā)不安全，這導(dǎo)致汽油易爆。此外汽油揮發(fā)到空氣中不環(huán)保。注意，安全跟安全不是燃點(diǎn)決定，單一介質(zhì)不會(huì)爆炸，爆炸的都是混合物。鎂材很安全，但是鎂粉空氣混合物就有危險(xiǎn)。鎂粉的點(diǎn)燃溫度是 600 度，但是點(diǎn)火能不大，是240mJ。而汽油的點(diǎn)火能量更低，，不到1mJ。

Of course, they actually burn under high pressure. Diesel is and the diesel engine is compression ignition, which leads to a large allowable working range of the machine, no detonation and not easy to shut down (the diesel engine can even burn gasoline at high temperature). Gasoline has low ignition energy, volatile and unsafe, which leads to gasoline explosion. In addition, the volatilization of gasoline into the air is not environmentally friendly. Note that safety and safety are not determined by the ignition point. A single medium will not explode. What explodes is a mixture. Magnesium is safe, but magnesium powder air mixture is dangerous. The ignition temperature of magnesium powder is 600 degrees, but the ignition energy is small, which is 240mJ. The ignition energy of gasoline is lower, less than 1MJ.

當(dāng)然，柴油機(jī)有個(gè)缺點(diǎn)就是笨重，但是，差別沒你說的那么大。只要使用環(huán)境能夠接受這個(gè)重量，只能選擇柴油機(jī)。車用機(jī)器跟工業(yè)用機(jī)器不同的，尤其是發(fā)電機(jī)組。

Of course, the diesel engine has a disadvantage that it is bulky, but the difference is not as big as you say. As long as the operating environment can accept this weight, only diesel engine can be selected. Automotive machines are different from industrial machines, especially generator sets.

工業(yè)用引擎是幾乎一直在額定功率下工作的.什么叫額定功率？對(duì)于小車來說，就是快到紅線轉(zhuǎn)速，油門踩到底，并且還沒風(fēng)吹散熱！??！注意，即便你在高速上超速駕駛飆到兩百碼，也不是工業(yè)用及機(jī)器個(gè)環(huán)境，因?yàn)槟愕纳崞魇强孔诧L(fēng)冷卻的散熱的。你給我把水箱（散熱器）用紙皮擋住飆高速試試！一下就開鍋了。

Industrial engines almost always work at rated power. What is rated power? For the car, it is fast to the red line speed, the accelerator is pressed to the end, and there is no wind to dissipate heat!!! Note that even if you drive to 200 yards at high speed, it is not an industrial and machine environment, because your radiator is cooled by the impact wind. You try to block the water tank (radiator) with paper! It'll boil in a minute.

小車的發(fā)動(dòng)機(jī)（汽油機(jī)）按照規(guī)范是不需要也不允許長(zhǎng)時(shí)間大功率工作的，當(dāng)然，大車的發(fā)動(dòng)機(jī)（柴油機(jī)）按照規(guī)范需要能夠長(zhǎng)時(shí)間大功率工作。

The trolley engine (gasoline engine) does not need and is not allowed to work at high power for a long time according to the specification. Of course, the crane engine (diesel engine) needs to be able to work at high power for a long time according to the specification.