汽油车为什么可以改装使用天然气，我一直挺困惑的，由于油价不断上涨，改装天然气的人也越来越多了。
Why gasoline vehicles can be converted to use natural gas, I have been quite confused, due to rising oil prices, a modified gas are also more and more.
“使用天然气作为燃料的工作原理与原来的汽油机相同。将高压气瓶中储存的天然气经过减压后送到混合器中，在此与空气混合，进入汽缸。仍然使用原汽油机的点火系统中的火花塞点火。原汽油机的压缩比不改变，原来发动机的结构基本不变，只是另外加上天然气的储气瓶、减压阀及相应的开关。改装费用较低，而且用天然气或汽油两种燃料都可以工作虽然天然气的抗爆性很好，允许在较高的压缩比下工作，但因为在改装时为了使原发动机仍可用汽油工作，故原发动机的压缩比没有改变，发动机的功率要损失10%～20%。为了减少功率损失，可在改装时把原来汽油机的压缩比提高(最简单的办法是将汽缸盖刨去一部分)，并改变点火提前角以适应天然气的工作需要。这样虽然可以减少工率损失，但再用汽油工作时将会有产生爆震的危险，甚至于不能工作。难以回到原来的汽油机工作方式。所以目前汽油车改装时，发动机的压缩比一般保持不变。 ”
"The principle of using natural gas as a fuel is the same as the original gasoline engine. The storage of natural gas in high pressure gas cylinders after pressure relief to the mixer, the mixed with air, into the cylinder. The spark plug still use the original gasoline engine ignition system. The original gasoline engine's compression ratio doesn't change, the structure of the original engine basically remain unchanged, but in addition to the air cylinder, pressure reducing valve of the gas and the corresponding switch. Modification cost is low, and use natural gas or gasoline both fuel can work while gas antidetonating quality is very good, allowed to work at a higher compression ratio, but because in a modified in order to make the original is still available gasoline engine, so the original engine's compression ratio has not changed, the engine's power loss of 10% ~ 10%. In order to reduce the power loss, can be modified to increase the compression ratio of the original gasoline engine when (the most simple way to go is dug cylinder cover part), and changing the ignition advance Angle in order to meet the needs of the work of natural gas. Although this can reduce the rate of loss, but with gasoline to work there will be risk of detonation, even unable to work. Work hard to return to the original gasoline engine. So the car, petrol engine compression ratio generally remain the same."
济南汽车油改气的原理：当NGV的发动机启动后，天然气便从储气瓶流入燃料软管中。 在发动机附近，天然气将进入压力调节器从而实现降压。 然后，天然气将进入多点气体燃料喷射系统，该系统会将其引入气缸中。 传感器和计算机将对燃料和空气的混合气体进行调节，以便火花塞点燃天然气时，燃烧更有效。
Jinan car oil to gas principle: as the NGV engine starting, natural gas from gas bomb into the fuel hose. Near the engine, will enter the natural gas pressure regulator so as to realize the decompression. Then, gas will enter a multipoint gas fuel injection system, the system will into the cylinder. Sensors and a computer will be adjusted for fuel and air mixed gas, natural gas, so that the spark plug ignites more effective combustion.
