Natural gas heavy truck and vehicle gas cylinder industry in-depth report

(1) CNG filling station: mainly serves taxis and some private cars, with a slow growth rate

CNG filling station is the earliest, largest and most complete filling station construction mode in China, mainly located in urban areas and surrounding areas. The CNG filling station can be divided into conventional station, mother station and sub-station: the conventional station is built in the place where the natural gas pipeline passes through, and the gas in the pipeline is desulphurized, dehydrated and compressed to 25Mpa before entering the conventional station, and then entering the gas selling machine to fill the car. The mother station is mostly built near the Chengmen station. After the gas desulfurization and dehydration in the natural gas pipeline, the pressure of 1-1.5Mpa enters the mother station. The mother station can gas the vehicle, and the natural gas is also transported to the sub-station by tank truck. Sub-stations are built at a distance from natural gas pipelines, usually within cities.

CNG filling station mainly includes natural gas pretreatment system, compression system, storage system, gas selling system and control system. 1) The natural gas pretreatment system includes desulfurization, dehydration and other processes of the natural gas entering the filling station. Desulfurization can prevent the corrosion of the equipment pipeline or the "hydrogen embrittling phenomenon" of the gas cylinder, and dehydration can prevent the ice blockage in the process of decompression, expansion and cooling of CNG; 2) The compression system is mainly composed of intake buffer tank, compressor host, lubrication system, cooling system, etc. 3) The storage of the filling station is usually divided into high pressure, medium pressure and low pressure bottle groups, which are automatically controlled by the control panel; 4) The gas selling system is composed of mass flowmeter, computer-controlled gas selling device and compressed natural gas gas circuit system, which is used to add fuel to CNG vehicles.

CNG filling stations are mature, the growth rate is slowing down, mainly serving taxis and some private cars. In 1988, China began to introduce the full set of CNG filling stations, refit automobile parts and high-pressure gas cylinders, and build CNG filling stations. In addition to some important components, the manufacturing technology and process of domestic CNG filling station equipment have been mature. CNG filling stations mainly serve taxis and some private cars, the technology is relatively simple, developed earlier in China, a large number, the current development is mature, the growth rate is slowing down. According to statistics, at the end of 2018, the number of CNG filling stations in China was 5,600, and the number of CNG filling stations in the future will continue to maintain an annual growth rate of 5%-10%.

(2) LNG filling station: mainly serves heavy trucks, and the northern layout is relatively perfect

LNG refueling station is a refueling station for LNG vehicles, which is mainly distributed in areas rich in LNG resources. LNG filling station mainly consists of LNG tank truck, LNG storage tank, LNG cryogenic pump, gas filling machine, pressure regulator and other systems, which can be divided into conventional station and skid-mounted station. The conventional station is built at a fixed location, and the LNG is stored in the storage tank through the gas unloading device, and the gas is added by the gas filler. The equipment related to the filling station is installed on the skid body or the car, which is small in scale and easy to transport.

The LNG filling station mainly includes four steps: unloading, pressure regulation, gas filling and pressure relief. 1) Unloading refers to the transfer of LNG in the tank or tank to the storage tank of the LNG filling station, there are three ways: supercharger unloading, submerged cryogenic pump unloading, supercharger and cryogenic pump unloading; 2) After the LNG is transported to the storage tank, the pressure is increased through the booster or the low-temperature circulation of the pump to obtain a certain pressure of saturated gas; 3) The air filler transmits gas to the vehicle cylinder through single or double lines; 4) When the LNG gasification in the tank causes the system pressure to rise, the BOG recovery system or safety valve will be opened to reduce the gas pressure.

China's LNG refueling station equipment manufacturing started late, but with the increasing demand for natural gas and consumption levels in China, the future number and proportion of LNG refueling stations are expected to increase, and will also drive the proportion of LNG heavy trucks to increase. The main reasons are as follows: 1) The downstream LNG vehicle has a broader application prospect. Taking heavy truck as an example, the transport radius of LNG heavy truck is larger, more suitable for long-distance transport, in addition, the gas filling speed is fast, and the cylinder loading efficiency is high. 2) The LNG filling station has strong filling capacity, is not affected by the gas supply network, is easy to locate, and has low investment cost and operating cost; 3) In the next few years, the increase of CNG pipeline gas is limited, and LNG imports are expected to grow rapidly. According to statistics, at the end of 2018, the number of LNG filling stations in China is 3,400, and with the advancement of natural gas vehicles, the number of LNG filling stations will continue to maintain an annual growth rate of 10%-20% in the future.