I make a popular science video and all the emperors learn from it!

【Electric locomotives are not without their shortcomings】

【Its main disadvantages are as follows:】

【1. The disadvantage of electric locomotives is that they have no power source of their own.】

【Electric energy comes from external cables or rails. If there is a power outage due to force majeure such as natural disasters or wars, it will not be able to operate, leading to transportation paralysis and even accidents.】

【In 2008, southern China suffered heavy snowfall, which damaged the power supply equipment along the railway lines, causing multiple electric trains to be suspended and causing serious passenger stranding. Hybrid power is a compromise solution, that is, an electric locomotive is equipped with an additional emergency diesel generator or a diesel generator carriage to cope with sudden power outages, but it will increase transportation costs.】

【2. The development, production and maintenance of electric locomotives and the construction, operation and maintenance of electrified railways require high costs and high-end technologies, resulting in the construction difficulty and maintenance cost of the entire railway system being higher than that of non-electrified railways. a lot of】

【If electrified railways are built in"803" environments such as economic poverty, sparse population, steep terrain, and harsh climate, it will impose stringent requirements on national or local financial pressure and technological level.】

【3. Electric locomotives rely on electrified railways, and a large number of power grid rail facilities will pose certain safety risks.】

【If someone breaks into the railway track or climbs on the roof of the train, it will cause an electric shock accident】

【If the high-voltage power grid of electrified railways in urban neighborhoods collapses unexpectedly, it may also cause electric shock.】

【Therefore, electric locomotives cannot completely replace diesel locomotives】

【The third stage of the train:】

【A diesel locomotive uses an internal combustion engine as the driving force and drives the wheels to rotate through a transmission device.】

【According to the fuel type of the internal combustion engine on the locomotive, most of the internal combustion locomotives used on the Huaxia Railway are equipped with diesel engines.】

【Fuel (diesel) is burned in the cylinder, and the thermal energy is converted into mechanical energy output by the diesel crankshaft. However, it is not used to directly drive the moving wheels. Instead, it is converted into mechanical energy suitable for the traction characteristics of the locomotive through the transmission device, and then drives the locomotive moving wheels through the running section. rotating on track】

【Diesel locomotives are the most widely used】

【In China, the concept of internal combustion locomotives traditionally refers to diesel locomotives.】

【In a diesel locomotive, a transmission device is installed between the internal combustion engine and the driving wheel, which is equally important as the engine and meets the traction characteristics. There are three types of transmission devices: mechanical transmission device, hydraulic transmission device and electric transmission device. A diesel locomotive equipped with an electric transmission device is called an electric transmission diesel locomotive, and so on.】

【Development:】

【At the beginning of the 20th century, foreign countries began to explore the trial production of diesel locomotives.】

【The world's first diesel locomotive started operating in 1913】

【In 1924, the Soviet Union built an electric-driven diesel locomotive and delivered it to the railway.】

【Huaxia began manufacturing diesel locomotives in 1958, and 3 types of locomotives were first put into mass production.】

【After 1969, 15 new models were mass-produced. Compared with the first generation of internal combustion locomotives, their power, structure, diesel engine thermal efficiency and transmission efficiency have been significantly improved.】

【Moreover, the functions of resistance braking or hydraulic braking and hydraulic reversing, locomotive system protection and fault diagnosis display, and microcomputer control have been added respectively; a series of new technologies such as load-bearing car body and hydrostatic drive have been adopted; the locomotive In terms of reliability and service life, performance has been greatly improved】

【The speed of the passenger locomotive reached 160 km/h】

【basic structure:】

【A diesel locomotive is composed of a diesel engine, transmission device, auxiliary device, running part of the car body (including frame, car body, bogie, etc.), braking device and control equipment, etc.】

【diesel engine】

【The power unit of an internal combustion locomotive, also known as a compression ignition internal combustion engine】

【The main structural features include the number of cylinders, cylinder arrangement, cylinder diameter, piston stroke, supercharging or not, etc.】

【Diesel engines used in modern locomotives are equipped with exhaust gas turbochargers, which use the exhaust gas of the diesel engine to drive the turbine compressor. The air with increased pressure is cooled by the intercooler and then sent to the diesel engine intake pipe, thus greatly improving the power and thermal efficiency of the diesel engine.】

【Diesel engines work in two ways: four-stroke and two-stroke. The thermal efficiency of a four-stroke engine at the same speed is generally higher than that of a two-stroke engine, so most of them use four-stroke engines. From the perspective of rotation speed, it is divided into high speed machine, medium speed machine and low speed machine.】

【In order to meet the needs of various power, products with various cylinder numbers with the same cylinder diameter and piston are produced. Those with smaller power use 6-cylinder, 8-cylinder in-line or 8-cylinder V, and those with larger power use 12-, 16-, 18- and 20-cylinder V. Among them, 12- and 16-cylinder ones are the most commonly used ones.】

【......】

【working principle:】

【The fuel burns in the cylinder, and the generated high-temperature and high-pressure gas expands in the cylinder, pushing the piston to reciprocate. The connecting rod drives the crankshaft to rotate and perform external work. The heat energy of the fuel is converted into mechanical work.】

【The power generated by the diesel engine is transmitted to the transmission device. Through the control and adjustment of the diesel engine and transmission device, the output speed and torque adapted to the operating conditions of the locomotive are sent to each axle gearbox to drive the driving wheel. The wheel circumferential traction generated by the driving wheel is transmitted to The vehicle frame changes from the coupler at the end of the vehicle frame to the draw hook traction force to drag or push the vehicle.】

【advantage:】

【The reason why diesel locomotives can suddenly emerge and catch up from behind】

【Mainly because it has the advantages of practicality, convenience, flexibility, quick start-up and low basic investment.】

【In addition, the oil price was cheap at that time, it was economically cost-effective, and the transportation efficiency was high. It was especially suitable for some lines where transportation was not too busy, the number of trains was not too many, and small shunting operations.......】

【Some developing countries with small road networks can purchase a few diesel locomotives from abroad and put them into use immediately to solve railway transportation problems. They can achieve"immediate" results.】

【Therefore, the vast majority of developing countries have adopted a policy focusing on internal combustion traction, allowing diesel locomotives to reach a large number of vehicles.】

【......】

The ancients were completely dumbfounded.

What, it’s not over! ? steam, electricity, fuel...

How can I make the train move?

Is it possible that except for the Qing Dynasty, people like to use mules to pull trains?

Other countries like to delve into things they cannot understand.

Qin Dynasty.

Ying Zheng was envious.

Now he hasn't even built a steam engine yet.

Light curtains have popularized science on diesel locomotives...

"What is electricity? Internal combustion, how is it ignited?"

He has one head and two heads.

But he understands the advantages of diesel locomotives. To put it simply, as long as there are diesel locomotives, fuel, and the rails are repaired, they can be put into use directly. (To read Baoshuang novels, go to Feilu novels Internet!) is more convenient than the previous two.

Tang Dynasty.

Li Shimin was dumbfounded.

There are only three of the four stages of the train.

Hurry up!

What is the last one?

In contrast, the Tang Dynasty summoned so many skilled craftsmen , couldn't even understand the simplest steam engine.

The gap with later generations made him despair.

In the Ming Dynasty,

Zhu Yuanzhang seemed to be petrified. He was silent for a long time.

Then he shouted to the people around him:"Give us the steam engine quickly. Get it out and see!"

People are more irritating than others."[]

Although he knew that the Ming Dynasty could not be compared with later generations.

But it can be seen that in less than a hundred years, the train has been greatly improved several times in succession.

Zhu Yuanzhang still couldn't help but be impatient..