In the course of the promotion of natural gas vehicles , natural gas vehicles fears , especially safety of CNG vehicles . This is a misunderstanding. Of course , natural gas is explosive gases , but the explosion of natural gas is conditional on taking a series of security measures, can be safely used for natural gas vehicles, like "electricity ", as it is characterized in the understanding of the future , opened today in their daily lives whether we are still in production , not all security applications with a large number of electrical devices?


□ First, the characteristics of the fuel itself , the gas ignition is generally above 650 ℃, while gasoline is 427 ℃. Day
Higher than gasoline, natural gas above 200 ℃, this description is not so easy to be ignited natural gas as fuel. Second, the volume of the combustion gas in the air boundary at the 5% to 15% , while gasoline is 1% to 7%. That atmospheric concentration of 1% of gasoline is very prone to fire explosion . Natural gas is much better than gasoline , because it needs to accumulate to 5 percent before reaching its lower flammable limit . More importantly, the gas is lighter than air , only 55% of the density of air , a slight leakage , readily diffuses into the atmosphere , will not reach the lower combustion limits. But also in the natural gas odorant when put to use in order to improve early detection of gas leaks and to take preventive measures. Most importantly, the proportion of gas in the air reaches the explosion limit of even without fire source will not explode. So the place to store natural gas must strictly prohibited fireworks.


□ Second, the gas engine fuel system components used much, some of the main switches and valves , mixers , etc. , the sealing member is a key to these problems . Material selection, processing, installation , height , etc. are under strict quality assurance conditions, there should be no security issues. In the natural gas vehicle refueling device, with automatic constant pressure , constant temperature control and shut-off valve. Oil switch on the car engine can automatically turn off after stopping the oil and gas supply.
□ CNG cylinder safety issue. For the cylinder pressure is 20Mpa , no matter what material , and go through the following rigorous safety testing.
    A hydrostatic pressure burst test
□ in the sample gas bottle filled with water , and pressurized to 56.5Mpa 10s maintained under a pressure not exceeding the speed 1.38Mpa / s conditions , and finally pressurized to destruction.
□ Second, pressure cycling test
□ between 2.5 ~ 25Mpa hydrostatic pressure cycle test was performed 13,000 times ; between 2.3 ~ 35Mpa 5000 test , each test 1min, so as not to crack or deform to pass.
□ Third, the fire test
    In the CNG cylinders filled with 25Mpa of natural gas, this gas cylinder with fire 20min, with the explosion does not occur as qualified.
□ Fourth, the drop test
    CNG will rise or higher air bottles 3m, falling to the concrete floor is repeated beating , then 10% to 100 % of the working pressure of the water cycle 13,000 times , no cracks as passing .
□ five shootings trial
    The vials filled 25Mpa CNG gas , at a distance of 46m with a speed of at 853m / s, a diameter of 0.3in empty shells on the bottle for 45 -degree shot. Cylinders should not be cracks .
□ In addition, the gas cylinder is also equipped with a safety valve , which is mounted fusible gold 26Mpa of the rupture disc 100 ℃ . When the gas pressure inside the cylinder , it will automatically deflate when the temperature exceeds the above values ​​. While compressed natural open vehicle development time is not long, but now the world is also about more than 100 million CNG vehicles , have not seen recorded in the operation due to traffic accidents caused by gas cylinder explosion of fire . Therefore compressed natural gas vehicles safer than gasoline cars.