1. How many liters of diesel are there in a cubic meter of natural gas? What's the conversion between natural gas and diesel oil?

This is the user's concern, LNG is saving money, but how much, from the conversion value may find the answer. The calorific value of 1 cubic meter of natural gas is 0.86 liters of diesel; A cubic meter of the gas produces as much power as 0.75 to 0.8 litres of diesel.

2. LNG filling station in some places with kilograms, some places with cubic meters of measurement, which is more reasonable?

Measure with kilogram and measure essence with cubic meter is same, it is measure unit is different only, determine according to local custom, different area measure unit should wait for comprehensive analysis according to customer circumstance, market condition and determine. Using cubic meters as units can adjust the sales price according to the change in the rate of gas, the kilogram is a more common unit of measurement. The vast majority of LNG refugers use mass flowmeters, with the smallest deviation measured by kg.If the standard measurement sales, it is necessary to consider the gas rate index pricing to ensure customer benefit.

3. Why does LNG filling sometimes add more and sometimes add less? (LNG is often filled with 450L vehicle-mounted bottles and tanks, and the filled LNG weight exceeds 200KG)

Due to the different gas source areas, the density, calorific value, gas rate, temperature of LNG will be slightly different, filling volume slightly fluctuate, does not affect the accuracy of gas metering. LNG filling equipment in accordance with the national standards, regularly by the national measurement department periodically verification, to ensure the accurate measurement.

4. How to calculate the gas intake of LNG tank trailers? How do I know when I need gas?

(1) LNG is measured in the same way as gasoline and diesel fuel. One is measured by volume and the unit of measurement is cubic meters (gasoline and diesel fuel is liter). The other is measured by mass and the unit of measurement is kg (gasoline and diesel fuel is ton). According to the measurement habits of different areas, cubic meter or kilogram can be chosen as the unit of measurement. No matter what the unit of measurement, the gas volume is the same, the gas can be automatically measured, the conversion relationship is 1 kg LNG about 1.4 square meters of natural gas.

(2) LNG truck cab is equipped with LNG liquid quantity display, and diesel tanker truck oil quantity display, liquid quantity display part includes liquid quantity icon, liquid quantity scale line, liquid quantity pointer and liquid quantity value (L). The key switch turns on the power, each parameter value of the cylinder will be displayed after 3 seconds of full light on the display screen, including liquid quantity and cylinder pressure value. Customers can choose the filling time according to the residual liquid value, when the liquid measure scale line below the liquid line (this data is determined by auto makers, fluid volume line generally 12.5% of effective volume cylinders), Red line of liquid volume scale line , status light flashing, remind customers to add liquid in time.

5. LNG tank truck refueling time is long? How long does a refill take?

It takes the same amount of time to fill the same volume of LNG and gasoline and diesel. The maximum capacity of LNG refueling machine is 150-200L /min, and the normal refueling time is 5 to 10 minutes.

6. What is the driving mileage of LNG heavy trucks?

The range of the LNG truck is determined by the volume of the LNG vehicle bottle and the gas consumption of 100 kilometers. It has a range of 400 to 1,000 kilometers, about the same as a diesel trucks. For example, the LNG heavy truck is equipped with two 450-liter vehicle bottles that can store about 500 cubic meters of natural gas, consume 50 cubic meters of gas for 100 kilometers, and can run for more than 900 kilometers.

7. What are the advantages of LNG vehicles and diesel vehicles?

(1) Long driving mileage: LNG heavy truck with 450L bottles can travel more than 400Km, short refueling time.

(2) Better economy: the vehicle saves fuel cost, the equipment is simple, the maintenance cost is low, and the overload effect is more prominent.

(3) High safety: the ignition point of LNG is 650℃, higher than that of gasoline and diesel; The explosion limit of LNG is 5%-15%, the explosion limit is narrower than that of gasoline and diesel, and the density after gasification is very low, a little leakage is volatile diffusion.

(4) Clean environmental protection: pure LNG components, CO and other emissions are less, the environmental effect is obvious.

8. Can natural gas trucks run on diesel?

At present, China natural gas heavy trucks are using a single fuel, that is, can only use compressed natural gas CNG or liquefied natural gas LNG, can not use diesel. Because the working principles of diesel and natural gas are quite different, diesel is compression ignition type and natural gas is ignition type, so generally speaking, gasoline and natural gas can be mixed, but diesel and natural gas can not be mixed.

9. How much gas does a LNG trucks(concrete mixing truck, cement tanker truck, long-distance bus, bus, tractor) consume in the actual operation of 100 kilometers? How does that compared to diesel?

LNG trucks in the actual operation of 100 kilometers of gas consumption compared with the same power of diesel vehicles, according to the influence of different gas source quality, about 1.3 square natural gas to replace 1 liter of diesel, for example: 100 kilometers of fuel consumption of 40 liters of heavy truck, the same power of LNG heavy truck 100 kilometers of gas consumption of about 50 square.

10. Why should the LNG tank be deflated often? Will it be dangerous?

If the LNG vehicle is not used for a long time, the pressure in the cylinder will increase due to the continuous gasification of the liquid in the cylinder. When the pressure exceeds a certain value, the secondary safety valve of the cylinder automatically opens to relieve pressure, to ensure the safety of the cylinder, in the secondary safety valve failure or failure, the main safety valve, so as to protect the safety of the cylinder; When an accident occurs, such as the cylinder shell is destroyed by external force, vacuum failure or the system pressure rises sharply, the main and secondary safety valves are opened successively to relieve pressure to ensure the safety of the vehicle. When the cylinder is deflated, because the main component is methane, methane is lighter than air, volatile, and not easy to accumulate dangerous.

11. In the process of filling the natural gas vehicle, the filling station requires that no one can sit in the cab, because it is unsafe?

Flash point comparison:

Diesel oil: burning point 220℃; Gasoline burns at 427℃. But gasoline volatile, gasoline steam to diesel low flash point, liquefied petroleum gas LPG flash point 490℃, natural gas flash point 650℃.

Specific gravity comparison:

Liquefied petroleum gas (LPG): with the proportion of air 1.5 ~ 2, leakage when the deposit, easy to cause explosion safety risks.

Natural gas (NG) : with the proportion of air 0.5 8 ~ 0.79, leakage will quickly volatilize into the air, not easy to cause safety risks.

Explosion limit comparison:

Liquefied petroleum gas (LPG) : 1.7% ~ 9.7%. It is prone to explosion.

Natural gas (NG) : explosion limit 5 ~ 15%. Not prone to explosion.

Pressure comparison:

LNG charging pressure is lower than CNG, about 1/40 of CNG charging pressure, not easy to leak. The filling pressure of LNG is only 0.5mpa, while that of CNG is 20Mpa.

As can be seen from the above, the safety indicators of LNG are higher than those of common fuels, so the safety of LNG as fuel is higher than other fuels. However, in order to better ensure the safety of passengers, to ensure the control of open fire hidden danger in the filling station, for the effective control of safety risks, it is required that no one can sit in the cab when filling the filling station.

12. Are LNG cylinders safe?

LNG storage cylinders should be specially inspected before leaving the factory. After routine inspection, gas cylinders should be inflated for fire, explosion, falling, shooting and other tests. After passing the test, they can be used before delivery. Automobile LNG cylinder is designed as a low temperature adiabatic pressure vessel with a double layer (vacuum) structure. The inner tank is used to store the low-temperature liquid natural gas (LNG). The outer wall of the tank is wrapped with multiple layers of insulation material for super thermal insulation, while the jacket (the space between the two layers of the container) is pumped into a high vacuum to form a good insulation system. The housing and support systems are designed to withstand the forces associated with moving the vehicle.

The tank design has two stage safety valve to protect against overpressure. In the case of overpressure, the first to open the main safety valve (opening pressure of about 1.6MPa), its role due to the insulation layer and support normal heat leakage loss caused by the pressure rise, or vacuum is destroyed and in the misfire conditions of accelerated heat leakage caused by the pressure rise. The pressure set point of the secondary safety valve (the opening pressure is generally above 2.4mpa) is higher than that of the main safety valve. When the main safety valve fails or is blocked, the secondary safety valve starts.

The protection of the housing against internal overpressure conditions is achieved by an annular suction plug. If the liner leaks (resulting in excessively high jacket pressure), the suction plug will open to relieve pressure when the pressure reaches 0.1 ~ 0.2 MPa. In case the vent plug leaks and the vacuum is destroyed, "sweating" (large area of water droplets) or even frost can be found on the shell. Of course, frosting or condensation at the end of the pipe connected to the cylinder is normal. All lines and valves are arranged at one end of the cylinder and protected by a guard ring or protective cover.

13. Will LNG easy to explode when there is accident or collision?

LNG is stored in the adiabatic container with pressure of 0.05 to 0.5mpa. Compared with CNG, the storage pressure is small, and the density of LNG is low after gasification (lighter than air). Once there is leakage, volatilization and diffusion, it is not easy to explode. LNG ignition point of 645℃, explosion limit of 5%-15%, liquid LNG is not easy to ignite, safer than gasoline and diesel. LNG storage cylinders should be specially inspected before delivery. After conventional inspection, gas cylinders should be inflated for fire, explosion, fall, shooting and other tests, the vehicle generally will not be damaged after the collision, once leak, due to light than air, quickly volatile, should not gather combustion.