What causes the very low efficiency of a fuel engine?

Because of mechanical losses and engine thermal balance。The performance index of the engine is used to characterize the performance characteristics of the engine and as the basis for evaluating the performance of various engines. Generally, there are dynamic indicators, economic indicators, strengthening indicators, compact indicators, environmental indicators, reliability indicators, durability indicators, manufacturability indicators, internal combustion engine speed characteristics, etc.

Effective torqueThe torque output from the engine is called the effective torque, which is the torque of the engine.

Effective power. The effective work output of the engine per unit time is called effective power, that is, the power of the engine, which is equal to the product of the effective torque and the angular velocity of the crankshaft. Average effective pressureThe effective work emitted by the working volume of the unit cylinder is called the average effective pressure, and the greater the average effective pressure, the stronger the working force of the engine.

Effective thermal efficiency. The percentage of heat generated by fuel combustion that is converted into effective work is known as effective thermal efficiency. The higher the effective thermal efficiency, the better the economy of the engine.

Effective fuel consumption rate. The amount of fuel consumed by the engine per 1kw of effective work output is called the effective fuel consumption rate, and the lower the effective fuel consumption rate, the better the economy.

liter power. Under the calibration condition of the engine, the effective power output per unit engine displacement is called liter power. The high power per liter indicates that the effective power emitted by the working volume of each cylinder is large, and the thermal and mechanical loads of the engine are high.

Reinforcement factor. The product of the average effective pressure and the average speed of the piston is called the reinforcement coefficient.

Specific volume. The ratio of the engine's profile volume to its rated power is called the specific volume.

than quality. The ratio of the dry mass of an engine to its rated power is called the specific mass. Dry mass refers to the quality of the engine without fuel, oil, and coolant. The smaller the specific volume and specific mass, the more compact the engine structure.

Reliability indicators. The reliability index is an index that characterizes the ability of the engine to work normally and continuously under the specified use conditions.

Durability indicatorsThe durability index refers to the extreme time that the main parts of the engine are worn to the point where they can no longer continue to work properly.

Manufacturability indicators。Manufacturability index refers to the index to evaluate the quality of engine manufacturing manufacturability and maintenance process. If the engine structure has good manufacturability, it is easy to manufacture and maintain, which can reduce production costs and maintenance costs.

Among these indicators, the effective thermal efficiency of the engine is the main economic index, that is, how much fuel consumed by the engine is converted into the effective work of the engine. Under the existing conditions, the thermal efficiency of the general gasoline engine is, and the thermal efficiency of the diesel engine is.

The oil has high impurities, coupled with uneven combustion, and the energy cannot be used 100%, and the efficiency is low.

The fuel contains impurities and is not pure fuel, so it is very inefficient.

The resulting inefficiency of a gasoline engine may be due to its engine thermal imbalance.

It may be that the fuel burns inadequately, resulting in low engine efficiency.

It could be because of the quality of the gasoline, or it could be because of the driver's improper driving style.

Because of the torque problem of the engine, performance, economic indicators, etc.

The torque output from the engine is called the effective torque, which is the torque of the engine.

The fuel engine needs to be fully used by gasoline to lift it at speed, but ordinary cars cannot do it.

It is possible that the quality of the gasoline has become very low, or it may be the engine itself.

The lower, the better.

Fuel consumption is available in three categories: suburban, urban and combined. The so-called fuel consumption in urban and suburban working conditions is the accurate, reproducible and comparable test data obtained in the laboratory with standard instruments and equipment under standard conditions (standard temperature, humidity, atmospheric pressure, etc.). The fuel consumption under comprehensive working conditions is a combination of fuel consumption data of urban and suburban two cycles.

For gasoline, diesel, dual-purpose fuel and dual-fuel vehicles, fuel consumption data refers to the fuel consumption of urban, suburban and comprehensive working conditions measured in accordance with GB T 19233; For non-external plug-in hybrid electric vehicles, fuel consumption data refers to the fuel consumption of urban, suburban and comprehensive operating conditions measured in accordance with GB T 19753.

Car fuel precautions.

Only when the octane number of all gasoline of the gasoline engine adapts to the compression ratio requirements, can the power and economy of the gasoline engine be fully utilized. If for some reason in practice the selection of high or low pin grade gasoline, the ignition advance angle of the engine can be appropriately postponed, the oil level height of the float chamber can be appropriately increased, the main orifice needle valve should be appropriately enlarged, and care should be taken not to overload the work to reduce the knocking tendency.

On the contrary, when the vehicle using low-grade gasoline chooses high-grade gasoline, the ignition advance angle can be appropriately advanced, the oil level height of the float chamber can be appropriately reduced, and the needle valve can be adjusted to give full play to the excellent performance of high-octane gasoline, improve engine power and reduce gasoline consumption.

The working condition of the engine at the rated power and rated speed is called the calibration condition. The less heat and the higher the effective thermal efficiency, the better the economy of the engine. .Obviously, the lower the effective fuel consumption rate, the better the economy.

The lowest operating state of the engine fuel consumption rate is at full load.

The speed of the engine at full load is called "rated speed" or "at full load fixed speed" is called "rated power".

The power at the full load rated speed of the engine is called the rated power.

How the engine works:

Animation of how an in-line four-cylinder engine works.

The cylinders of engines below 6 cylinders are mostly single-row in-line square group accompaniment type, and a few 6-cylinder engines also have in-line mode. The in-line engine structure is simple and messy, and it is cheap, but the disadvantage is that the engine height is higher and the length is longer.

Animation of the working principle of the V-shaped six-cylinder engine.

The V-type engine divides all the cylinders into two groups, and the two groups of adjacent cylinders are arranged together at a certain angle, which can offset a part of the vibration, and the cylinders are V-shaped when viewed from the side, so they are called V-shaped engines.

The main reasons for the thermal efficiency of the diesel oil engine is higher than that of the gasoline engine are as follows:1The way it burns is different:

Diesel engines use compression-ignition combustion, while gasoline engines use spark-ignition combustion. In contrast, compression-ignition combustion is more efficient, because the spontaneous ignition point of the fuel is relatively low, and it can be directly spontaneously ignited under the pressure of the high-end hall, thus making the combustion more sufficient and improving the thermal efficiency. 2.

The calorific value of the fuel is different: Diesel fuel has a higher calorific value than gasoline, which means that when the same mass of fuel is burned, the diesel engine can produce more energy, which improves thermal efficiency. 3.

High compression ratio: Diesel engines have a higher compression ratio than gasoline engines, which means that when compressing air, diesel engines can compress more air into the same volume, resulting in more full combustion of fuel and improved thermal efficiency. 4.

Engine construction is different: diesel engines are generally more durable and robust than gasoline engines, able to withstand higher pressures and temperatures, resulting in more efficient conversion of thermal energy into mechanical energy and improved thermal efficiency. To sum up, the thermal efficiency of diesel engine is higher than that of gasoline engine, mainly due to the influence of combustion mode, calorific value of burning bucket hail, compression ratio and other factors.

1. Sensor failure; 2. The quality of gasoline is not up to standard; 3. The air leakage of the inlet pipe leads to the mixture being too thin; 4. The fuel pressure is low, and the injector and fuel filter are blocked; 5. The signal of the pressure sensor and the throttle position sensor is abnormal; 6. The ignition timing is inaccurate and the ignition is too late. 7. Weak high-voltage sparks due to poor spark plugs, igniters or high-voltage wires; 8. The throttle is dirty; 9. The exhaust gas recirculation system works poorly; 10. The exhaust pipe is blocked; 11. The cylinder pressure is low; 12. Turbocharging system failure 13. Clutch three-piece set 14 Air filter blockage, piston ring break or stuck, poor valve sealing, late ignition time, carburetor mechanical failure, air intake pipe leakage, individual cylinders do not work well or do not work, etc. However, some of the faults of insufficient engine power can be solved by use. Such as:

General wear of the cylinder, poor flow of the carburetor oil passage, etc. When the user reflects that the engine power is insufficient, when the oil is burned, we should first judge the cause of the lack of power, in the exclusion of the air filter blockage, the carburetor throttle can not be fully opened, the ignition timing is not good, the intake pipe gasket is damaged, the individual cylinder does not work or does not work well, and then according to whether the engine fuel consumption is too high to judge the carburetor working condition, if the fuel consumption is too high, the exhaust smoke is very thick, it is likely that there is a mechanical failure such as the volume hole falling off, this fault must be repaired as necessary. Finally, we have to judge the wear and tear of the engine cylinders.

Engine wear directly affects the tightness of the cylinder; Therefore, checking the tightness of the cylinder can largely reflect the degree of wear of the cylinder, and the most convenient way to check the tightness of the cylinder is to use the cylinder pressure gauge to check the compression pressure of the cylinder.

In fact, thermal efficiency, to put it in layman's terms, is how much of your liter of oil can be used to drive your car. Because there are always various losses in the combustion of engine gasoline. Just like a mobile phone, when it is hot in your hand, the battery energy of the mobile phone quietly runs away in the form of heat dissipation.

All the energy minus the energy lost by these losses, the remaining energy that can be really used by the mobile phone, and the proportion of all energy occupied by all energy is the "thermal efficiency". If you want to be more popular, let's use a metaphor that everyone likes. It's similar to how many apples you can buy for 100 yuan, some can buy 30 catties, and you can buy 40 catties.

That's what you're capable of! This explanation should be easy to understand. Achieved 13:

1 compression ratio, 40% thermal efficiency. The hybrid version also has a dual-cycle thermal efficiency of 41%. This kind of thermal efficiency has opened a new era in the automotive industry, and the only way to break through in the future is to go up according to this benchmark.

It's getting harder! For a gasoline engine, its thermal efficiency can reach about 40%, which is close to the theoretical maximum, and it is not much that it can be reached at present. @2019

As technology advances, more and more unimaginable technologies are being developed, and just recently, the new Camry surprised fans around the world by increasing the thermal efficiency of a naturally aspirated four-cylinder engine to 40 percent. Next, let Bian Xiao Auto briefly introduce to his friends what the 40% thermal efficiency of a gasoline engine means.

What exactly is thermal efficiency?

The term thermal efficiency sounds a bit boring. The strict explanation in the scientific books is the ratio of internal energy to kinetic energy per unit volume of fuel. The higher the ratio, the more efficient the fuel is at kinetic energy.

For the average consumer, it can be understood that the higher the ratio, the better the engine power, the lower the fuel consumption, and the better the emission level.

But did you know that energy loss in a car engine is inevitable? Nowadays, it is almost impossible for the engine thermal efficiency of all gasoline cars in the world to reach 50%, which also means that even if your car is filled with a tank of fuel, I feel that the power to the wheels is less than half, and most of it is basically used by various energy losses.

So, in addition to the fuel that is converted into kinetic energy and applied to the wheels, the rest of the gasoline is basically gone? Most of these fuels are carried away by the cooling of the engine, known as cooling loss, and some of them are discharged into the atmosphere through exhaust, known as exhaust loss. These two pieces account for the largest proportion, about 40% of the total energy, but this is an unavoidable energy consumption, so the engine can &ldquo eat less food and run more.

We can only start with the remaining 60%.

If you want the horse to run, you need to eat less grass. This is an eternal problem, and it is no different in the automotive sector. In addition, cars need to consider not only energy consumption, but also increasingly stringent emission regulations.

Take, for example, the United States, a major automobile country. By 2025, the average fuel rationality (CAFE) of the vehicles sold by each automaker must be equivalent to, or basically the same double standard. Yes.

In light of this, major automakers are also working hard to develop new technologies to cope with the new regulations. In China, along with & ldquo six countries. The promulgation of emission regulations can be said to be one of the most stringent emissions regulations in the world in the future.

Solve problems and develop technologies.

In order to cope with this difficulty, many manufacturers have begun to rack their brains to develop new technologies, and the thermal efficiency of the engine is a key link that affects fuel consumption and emission data. For a car equipped with a 33% thermal efficiency engine (most car engines now have a thermal efficiency between 28% and 33%), the reasonable fuel performance of the whole vehicle will be improved by 15%-20% after using a 40% thermal efficiency engine.

Based on an average fuel consumption of 7 liters per 100 kilometers and a car driving 10,000 kilometers per year, the use of an engine with a thermal efficiency of 40% can save at least 200 liters of gasoline per year, which can save more than 1,300 yuan in fuel costs. The 200 litres of gasoline saved not only saves a lot of money on fuel, but also contributes to environmental protection around the world.