Advantages of LNG

Compared to LPG and CNG, the advantages of LNG as an alternative fuel for vehicles are as follows:

(1) Clean and Environmentally Friendly. As a fuel for vehicles, LNG must first be vaporized by a vaporizer and then enter the engine in a gaseous state for complete combustion. Due to the high methane content of 90% to 99% in the composition of LNG, the exhaust contains very low levels of harmful substances, making it highly clean and environmentally friendly.

(2) High unit price calorific value. Compared to other fuels, LNG is priced lower and offers a higher calorific value per unit. The low-temperature properties of LNG can reduce the temperature of the mixed gas and combustion temperature, thereby enhancing the engine's thermal efficiency. This effectively ensures that LNG burns more completely and thoroughly within the engine than LPG, CNG, diesel, and gasoline. Adding to this, LNG's high energy density and storage efficiency make it more suitable for transportation and usage across a wider geographical area. Therefore, LNG boasts strong economic and applicability attributes.

(3) High safety. LNG fuel tanks allow working pressures up to 1.586 Mpa, with factory-set operating pressure ranging from 0.1759 to 1.4074 Mpa. The advantages of natural gas, compared to CNG, are lower risk of incidents. Automotive LNG tanks typically use double-layered metal vacuum powder insulation or double-layered metal vacuum wrapped insulation structures, offering high thermal insulation efficiency and long-term non-vacuuming capability. LNG, upon vaporization, has a lower density than air under normal pressure, so even in the event of a leak, it will quickly disperse into the air. The risk of spontaneous combustion is low. Additionally, the composition of LNG is relatively stable, with its single and consistent composition facilitating the determination of design parameters such as engine compression ratio, thus avoiding the adverse effects of爆燃 from components like ethane and propane. As a substitute fuel for vehicles, LNG ensures smooth engine operation, reduces noise pollution, and can save over 50% in engine maintenance costs compared to conventional fuels.

Advantages of LNG

Compared to LPG and CNG, the advantages of LNG as a substitute automotive fuel are as follows:

(1) Clean and environmentally friendly. As a fuel for vehicles, LNG must first be vaporized by a vaporizer and then enter the engine in a gaseous state for complete combustion, resulting in extremely low levels of harmful substances in the exhaust, making it highly clean and eco-friendly.

(2) High calorific value per unit price. Compared to other fuels, LNG offers a lower price and higher calorific value per unit. The low-temperature characteristics of LNG can reduce the temperature of the mixed gas and the combustion temperature, thereby improving the engine's thermal efficiency. Consequently, LNG boasts strong economic value and applicability.

(3) High safety. LNG fuel tanks typically allow working pressures of 1.586 MPa, with vehicle LNG storage tanks often using double-layered metal vacuum powder insulation or double-layered metal vacuum spirally wrapped insulation structures, which offer high thermal insulation efficiency and can maintain a longer period without venting.

(4) Easy to Install. Compared to CNG fueling stations, LNG fueling stations have smaller land requirements, no noise, and lower operating costs. The initial investment for setting up an LNG station is more than 30% less than that of a CNG station, and it can also reduce daily operation and maintenance costs by over 50%. Due to the LNG fueling station's lack of restriction from natural gas sources and pipelines, it can be designed as a fixed station for natural gas or as a skid-mounted unit, offering high mobility.

(5) High efficiency of cold energy recovery. LNG is stored and transported at atmospheric pressure and low temperature, releasing a large amount of cold energy when it is vaporized to normal conditions. Currently, the recovery rate of LNG's cold energy can reach 50%, with 1 cubic meter of LNG capable of recovering and utilizing 960 to 1095 MJ of cold energy. For instance, an average refrigerated truck absorbs 56.16 MJ of heat daily during operation. To absorb this heat, a standard diesel refrigeration system would require about 15 liters of diesel. In an LNG vehicle, the cold energy released from vaporizing 143 liters of liquefied natural gas can fully absorb the 56.16 MJ of heat, significantly enhancing economic benefits. Using LNG cold energy for car air conditioning or refrigerated trucks eliminates the need for a dedicated refrigeration system, saving energy and reducing noise pollution from mechanical refrigeration.

(6) Wide Range of Application. By adding a high-pressure pump and a high-pressure gasifier to the LNG fueling system, an LNG-CNG fueling station can be established, allowing for direct conversion of LNG to CNG. This station can fuel both LNG and CNG vehicles, thereby avoiding the need for fuel system modifications in CNG vehicles and eliminating the limitations of CNG fueling stations due to natural gas sources and pipelines. The expandability of the LNG fueling system further broadens its applicability.