In recent years, the government has continuously improved its efforts to control vehicle exhaust emissions, and diesel prices have also been rising. More and more car owners are turning their attention to the field of new energy heavy-duty trucks. Under this trend, the sales of new energy heavy-duty trucks have also been steadily increasing, forming a sharp contrast with traditional fuel heavy-duty trucks.

Natural gas heavy-duty trucks are an important branch of new energy heavy-duty trucks, referring to a type of vehicle that uses natural gas as fuel. The common types in the market mainly include LNG and CNG.

LNG is a liquid form of natural gas, which fully utilizes the characteristics of natural gas liquefaction at atmospheric pressure and -162 ℃, and its volume can be reduced by about 600 times; CNG, also known as compressed natural gas, is the process of compressing conventional natural gas using a compressor to maintain its gaseous state. The main differences between these two are reflected in the following aspects:

1. Storage method:

LNG is generally stored in low-temperature storage tanks at around -161.5 ℃ and 0.1MPa, and is filled to LNG heavy-duty trucks through refueling stations. The gas tank on LNG heavy-duty trucks generally adopts a double-layer vacuum structure, with an inner tank storing liquefied natural gas. The outer wall is designed with multiple layers of insulation materials, and a vacuum state is formed between the two layers of containers. When the vehicle is working normally, the air pressure inside the heavy-duty truck gas tank is maintained between 0.8MPa-1.4MPa.

CNG is generally stored in pressure vessels with a pressure range of 20MPa-25MPa, mainly relying on the natural gas pipeline system. After passing through the CNG compressor, it is filled to vehicles through the CNG refueling station. The pressure of the gas storage tank equipped on CNG heavy-duty trucks is generally 20MPa. The commonly used material for the gas storage tank is steel/aluminum, with a lining wrapped with fiberglass or carbon fiber.

2. Endurance:

From the state of the two fuels, it can be seen that the density of LNG and CNG is different. Among them, LNG has a higher energy density per unit volume, with 1 volume of LNG ≈ 600 standard volumes of natural gas; The CNG density is relatively low, with 1 volume of CNG ≈ 200 standard volumes of natural gas. In other words, if the volume of the gas storage tanks is the same, LNG heavy-duty trucks can add more fuel. At the same time, LNG has good combustion performance, high calorific value, can release more sufficient power, and naturally has stronger endurance.

3. Fuel cost:

The prices of LNG and CNG also vary in different regions. Objectively speaking, CNG mainly relies on pipeline transportation and has a relatively long history of use. It is widely used in public transportation vehicles, livelihood projects, etc., and its price is relatively stable; LNG requires deep cooling and has higher production costs than CNG. It is generally transported over long distances and is more susceptible to factors such as international markets and winter gas shortages, resulting in significant price fluctuations and relatively high prices.

4. Filling speed:

The refueling speed of vehicles is directly related to their operational efficiency and is also a concern for car owners. In general, the refueling speed of LNG heavy-duty trucks is faster than CNG heavy-duty trucks, and it takes 5-10 minutes to fill the 1000 liter tank body; The refueling time for CNG heavy-duty trucks is generally around 40 minutes. If considering the situation where buses and taxis queue up to refuel in some cities, a longer waiting time is required.

5. Gas station coverage:

At present, the number of refueling stations in China is at a leading level in the world. As early as 2020, China had built 10800 natural gas refueling stations, including approximately 4300 LNG refueling stations and 6500 CNG refueling stations. So, the coverage of CNG refueling stations is greater than that of LNG refueling stations. However, the range of LNG heavy-duty trucks is long, and they can run thousands of kilometers with just one addition, which to some extent determines that the number of LNG refueling stations is less than that of CNG refueling stations.

As for which one is better between LNG heavy-duty trucks and CNG heavy-duty trucks, it depends on the actual driving experience of the car owner. If you need to travel long distances, have higher requirements for transportation mileage and efficiency, or pursue stronger horsepower and higher cargo carrying capacity, then you can choose LNG heavy-duty trucks; If the owner's transportation route is not long and the requirements for transportation time are not too strict, then CNG heavy-duty trucks are a more economical choice.

Of course, car owners can also choose LNG+CNG dual fuel heavy-duty trucks. On the one hand, it can take into account the high efficiency and long endurance characteristics of LNG heavy-duty trucks, as well as the economic advantages of CNG heavy-duty trucks, and consider more transportation conditions; On the other hand, car owners can also selectively add gas based on the actual fuel price, which is cheaper and which is more cost-effective, further reducing the cost of using the vehicle; At the same time, it can also achieve peak shaving and energy replenishment, improving the operational efficiency and convenience of vehicles.

However, this dual fuel combination heavy-duty truck is not without its drawbacks, such as high self weight, high selling price, and questionable reliability. In the current environment of poor transportation market, more vehicles and less cargo, and continuously low freight rates, car owners still need to choose carefully.