Types and characteristics of new energy vehicles Natural gas vehicles and LPG vehicles Natural gas vehicles are also known as "blue-powered" vehicles, which mainly use compressed natural gas (CNG), liquefied natural gas (LNG), and adsorbed natural gas (ANG) as fuels. Commonly known are compressed natural gas vehicles (CNGV). Liquefied petroleum gas vehicles (LPPG) use liquefied petroleum gas (LPG) as fuel. CNG and LPG are ideal ignited engine fuels with single gas composition, high purity, uniform mixing with air, complete combustion, low CO and particulate emissions, low combustion temperature and therefore low NOx emissions, superior lean burn characteristics, and low temperature Good starting and low temperature operation performance. The disadvantage is that the storage and transportation performance is worse than that of liquid fuel, the volumetric efficiency of the engine is lower, and the ignition delay period is longer. These two types of vehicles mostly use dual fuel systems, namely a gasoline or diesel fuel system and a compressed natural gas or liquefied petroleum gas system. The vehicles can be driven by any of these systems and can easily be transitioned from one system to another. Alcohol car Alcohol vehicles are vehicles that use alcohols such as methanol and ethanol as fuel. The most widely used is ethanol. Ethanol has a wide range of sources and mature production technology. The latest technology for producing ethanol from cellulose raw materials is available raw materials. Almost all agricultural and forestry waste, urban domestic organic waste and industrial organic waste are included. At present, alcohol vehicles are mostly driven by a flexible fuel blended with ethanol and gasoline or diesel in any ratio. It does not require engine modification and has good energy saving and pollution reduction effects. However, this blended fuel needs to be obtained with gasoline or diesel. For a considerable power, the fuel injection quantity must be increased. When the alcohol blending rate is greater than 15% -20%, the engine's compression ratio and ignition advance angle should be changed. Ethanol fuel has a low theoretical air-fuel ratio, low requirements on the engine air intake system, high anti-knock resistance, good volatility, uniform gas distribution, high thermal efficiency, and reduction of vehicle exhaust pollution by more than 30%. Hydrogen fuel car Hydrogen is a clean fuel. Hydrogen is used as fuel. It only needs to slightly modify the conventional spark plug ignition engine. Its combustion efficiency is higher than that of gasoline. The mixture can be leaner to a greater extent. The required ignition energy is small, which is conducive to fuel saving. Hydrogen can also be added to other fuels (such as CNG) to improve efficiency and reduce N02 emissions. Hydrogen's mass energy density is the highest among various fuels, but its volumetric energy density is the lowest, and its biggest barrier to use is storage and safety issues. BMW has been devoted to the development of hydrogen engines, and has developed a number of hydrogen engine cars. Its 7 series cars equipped with V12 hydrogen engines are the world's first mass-produced hydrogen engines. The engine can use two fuels, hydrogen and gasoline. DME Dimethyl ether (DME) is a colorless and odorless gas with excellent combustion performance, clean, high cetane number, good power performance, less pollution, and slightly pressurized is a liquid, very suitable for compression ignition engines Alternative energy sources, vehicles using this fuel can meet ultra-low emission standards. DME does not emit black gas to pollute the environment and produces 20% less NOX than diesel. Pneumatic car Cars that use compressed air, liquid air, liquid nitrogen, etc. as the medium and provide driving energy through endothermic expansion work are called pneumatic cars. The pneumatic engine does not undergo combustion or other chemical reactions. It emits air or nitrogen without pollutant radiation. Achieve zero pollution. At present, the more successful development is the compressed air powered vehicle (APV). The working principle is similar to the traditional internal combustion engine car, except that the energy for driving the piston connecting rod mechanism comes from high-pressure air. The source of APV media is convenient and clean, and the construction cost of social infrastructure is not high, so it is easier to build. The fuel-free combustion process has low requirements on engine materials and simple structure. It can learn from the existing internal combustion engine technology, so the development cycle is short, and the design and manufacturing are easy. But at present, the energy density and energy conversion rate of APV are not high enough, and the driving range is short. electric car The world's first electric vehicle (EV) was manufactured by Americans in the 1890s. EVs are roughly divided into battery electric vehicles (BEV), fuel cell electric vehicles (FCEV) and hybrid electric vehicles (HEV). A common feature of electric vehicles is that the vehicles are completely or partially driven by electricity through electric motors, which can achieve low and zero emissions. Battery electric vehicles are the earliest electric vehicles. Vehicles using lead-acid batteries have a large gap in power performance and driving range compared with traditional internal combustion engine vehicles. The use of high-performance nickel-metal hydride batteries or lithium batteries will greatly increase the cost. The fuel cell has an energy utilization rate of nearly 65%, and can achieve zero emissions and low noise. The newly developed high-performance fuel cell abroad has been able to achieve almost the same dynamic performance as the traditional internal combustion engine vehicle. The development prospect is very good, but the cost is a constraint The bottleneck of its industrialization. Hybrid electric vehicles combine the advantages of traditional internal combustion engine vehicles and electric vehicles while overcoming the shortcomings of the two. They have achieved rapid development in recent years and have achieved industrialization and commercialization. At present, China's own brand, BYD, has a place in this field. Its representative work E6, F3DM is the use of electric hybrid power. Vehicles fueled by vegetable oil In order to search for new energy sources that can replace petroleum, scientists have also turned their attention to vegetable oils, and are developing internal combustion engine oils using vegetable oils such as soybean oil, corn oil and sunflower oil as raw materials. Scientists are still studying biodiesel, which is a fuel that uses vegetable oil as a raw material. It will be used as a substitute for diesel in trucks and ships in the future. Biodiesel does not contain sulfur, so it does not pose a threat to the environment from acid rain. To produce biodiesel, chemists are esterifying vegetable oils to make them methyl ester compounds, which burns cleaner and have less residue in the engine.
Small computer system interface (SCSI) is an independent processor standard for system level interfaces between computers and intelligent devices (hard disks, floppy drives, optical drives, printers, scanners, etc.). SCSI is an intelligent universal interface standard.
SCSI-3 Plastic SCSI Cover ShenZhen Antenk Electronics Co,Ltd , https://www.antenkconn.com
In 1995, the more high-speed SCSI-3, called ultrasci, was born, and the data transmission rate reached 20MB / s. It increases the synchronous transmission clock frequency to 20MB / s and improves the data transmission rate. If 16 bit wide mode is used, the data transmission rate can be increased to 40MB / s. This version of SCSI uses a 68 pin interface, which is mainly used on hard disks. The typical characteristic of SCSI-3 is that the bus frequency is greatly increased and the signal interference is reduced to enhance its stability.
There are many models of SCSI-3. Ultra (FAST-20) has a transmission frequency of 20MHz, a data bandwidth of 8 bits and a transmission rate of 20MBps
Ultra wide has a transmission frequency of 20MHz, a data bandwidth of 16 bits and a transmission rate of 40mbps
The transmission frequency of ultra 2 is 80 MHz, the data bandwidth is 16 bits, and the transmission rate is 80 Mbps
The transmission frequency of ultra 160 is 80 MHz, the data bandwidth is 16 bits, and the transmission rate is 160 Mbps
The transmission frequency of ultra 320 is 80MHz, the data bandwidth is 16 bits, and the transmission rate is 320mbps
The transmission frequency of ultra 640 is 160MHz, the data bandwidth is 16 bits, and the transmission rate is 640mbps
Since the end of the last century, countries and major automobile companies in the world, as well as major domestic scientific research institutions and colleges and universities have been committed to the development of clean and energy-saving vehicles, and new energy vehicles have made great progress. Gasoline and diesel are the energy sources of traditional internal combustion engine vehicles, and vehicles that use other energy sources to provide steam power can be called new energy vehicles. New energy sources currently under development include natural gas, liquefied petroleum gas, alcohols, dimethyl ether, hydrogen, synthetic fuels, biogas, air, and charge fuel cells. This shows that the development of new energy sources is imperative.