National III emission standards?

Since the implementation of the National III emission standard on July 1 last year, the four major technical routes that occupy the domestic commercial vehicle market and its supporting vehicles have been undergoing technological improvements. However, the “National III is more expensive than the State II”. Still come and go. So far, the heavy truck EGR engine that occupies the largest market share in the country III has the biggest demand for fuel, and the market share of Bosch's high-pressure common rail, “EFI” technology and single pump has also been depleted due to problems such as overload, road conditions, and oil quality. High oil content. All these have caused people to question the implementation of the “State III” emission regulations, and this has also affected the implementation of the III emission standards for commercial vehicles under 3.5 tons on July 1 of this year.

Heavy-duty EGR, which is based on exhaust gas recirculation technology to meet the national III standard, was once considered to be the biggest winner of State III technology. Nowadays, a large number of truck manufacturers in China are using electronically controlled EGR engines produced by Sinotruk, and the major domestic engine manufacturers are Developed their own EGR engines one after another, just because the uncertainty of market demand has not formed too much output.

In addition, host companies such as Weichai, Yuchai, Dongfeng and FAW have also developed a lower-cost mechanical pump-mounted EGR.

HOWO cement mixer truck is installed heavy truck EGRWD615 State III diesel engine.

● I purchased 4 HOWOs. Overloading is not large, but the machine is just like drinking oil. It consumes too much fuel, and it doesn't work when climbing.

With the country III engine than the State II fuel consumption increased by more than 10%, there is a control valve button in the cab, the button to open the change of the country III fuel consumption, off the country II but fuel-efficient.

● The oil consumption is as high as 100 km 55-65L. The fleet also has high-pressure oil pipe breakage, high-pressure oil pumps do not feed into the machine, the supercharger oil pump breaks, the throttle bracket breaks, and the oil at the bottom of the diesel enters frequently. After the implementation of the fuel tax, such "oil tigers" are even more unaffordable.

● Although SCANIA and MAN also use EGR as State III, they use advanced fuel injection systems. The heavy-duty EGR engine is a self-developed technology, and the reliability has not yet been verified by the market. The engine is controlled by six oil pumps and six injectors. As the injection pressure increases, the reliability decreases. Moreover, the non-complying exhaust gas is re-entered into the cylinder to reduce the content of nitride in the exhaust gas and reach the national III emission standard.

In addition, EGR engines due to the recirculation of exhaust gas and particles will significantly affect the performance of the engine, especially when the engine is idle, low speed, low load, and cold, it is easy to cause cylinder volume carbon and excessive fuel consumption.

● Because the catalyst is attached to the carrier inside the catalytic converter, when the exhaust gas passes through the carrier, a chemical reaction is produced to reduce the emission of pollutants, which also causes air resistance, resulting in oil consumption. Moreover, the requirements for NOX and CO in the country III are much lower than those in the country II. For as many COs as possible and as little NOX as possible, the manufacturer's solution is to adjust the ignition angle so that the gasoline does not burn completely. This causes a slight cost of oil and is related to the exhaust resistance.

At present, the use of "EFI" technology in domestic engines is still relatively small. Dongfeng, Shaanxi Automobile and other vehicle companies have adopted. An excellent mixture is the key factor in improving the power and fuel economy of diesel engines and reducing the emission rate and noise rate of "EFI" engines. This requires that the injection start point and fuel injection quantity must be accurately controlled, and the technical requirements are relatively high.

Shaanxi Auto's second-generation national III heavy trucks use Cummins fully electronically controlled pump nozzle technology to meet the requirements of the National III emission standards.

● Under full load and no-load conditions, the starting performance of the whole vehicle is very good, and the power is obviously increased. It is strong and is suitable for the bad working environment of coal. However, maintenance matters are more complicated and fuel consumption is also higher than that of State II.

"EFI" engines are technically more technical than mechanical pump engines, but why do a few users still complain about the cost of "EFI" engines? The main reason is that the computer program inside the "EFI" engine is not up to the users. Use a tight fit of working conditions.

● The engine increases the advanced no-load, light-load, full-load three-level conversion fuel saving function, the user can set according to the actual use of the vehicle, and the perfect cooperation with the fuel injection control program to make the vehicle work in the best condition, the fuel consumption Can greatly reduce, and improve the overall vehicle economy, increase revenue.

In addition, the Cummins III engine has upgraded the engine fuel filtration system. The fuel filter with oil-water separation and heating functions can filter the moisture and impurities in the fuel and filter the particulate matter in the diesel fuel. The moisture in the diesel fuel is enhanced. The separation capability makes Engine II oil products more adaptable.

Although EGR currently occupies a large share of the market, common rail technology has been considered by the industry as the mainstream of future technologies. The main contribution of the common-rail fuel injection system is to completely separate the injection pressure generation and injection process from each other, and to achieve precise control of the oil pressure in the common-rail tube so that the pressure of the high-pressure fuel pipe is basically independent of the engine speed.

At present, major domestic OEMs also use the common rail technology for the National III engine.

In addition to heavy-duty trucks, EGR-laden trucks do not have environmental protection notices for the time being. Therefore, in the eight central cities, common-rail sales are also widespread. FAW Aowei III diesel engines use common rail technology.

● State III common-rail engines will be particularly costly if they are overloaded, and some brands of State III cars will also have oil-fighting phenomena. Failure to add regular oil will lead to breakdowns and even necrosis. In addition, the engine is also easy to lock, the price is still more than 20,000 yuan.

● In terms of the HOWO common-rail truck I drive, the State III is not more fuel-consuming than the State II. It transports reinforced materials for the construction site. It often has an overload of 20 to 30 tons. It runs normal roads and adds regular petrochemical oil. Compared with the original use of the State II fuel economy. The fuel consumption depends on the driver's law, road conditions, and cargo volume. High-pressure common rail electric control trucks, diesel combustion is relatively full, the machine is relatively clean, less maintenance.

● The state-of-the-art heavy-duty truck with electronically controlled common rails can't be overloaded. The fuel consumption after overloading can be very large because its fuel injection is controlled by a computer. Its fuel injection amount and injection time are based on pre-existing ECU characteristics. The figure is determined, and the overloaded condition is not the normal condition set by the engine, so the injection volume increases sharply.

● More than 210 horsepower III diesel engines, especially the electrically controlled common-rail countries III, consume at least 10% more than the national II engine oil. Therefore, all vehicle manufacturers only have to rack their brains to match the entire vehicle. If they do well, they can use fuel consumption. It is 4% higher than State II, which is not necessarily related to the diesel engine plant.

● The multi-power fuel-saving switch on the engine can meet the power demand of the vehicle under no-load, medium-load, heavy-load or different road conditions. Only when the driver selects three different power output modes of heavy load, medium load, and no-load according to different road conditions and different loading capacity can the purpose of fuel saving be achieved.

From the cost point of view, when the domestic engine is upgraded from Euro II to Euro III, if a single pump is used, the change to the engine is very small, and only the outboard camshaft box can replace the Euro II engine in-line pump.

Delphi uses a single pump system on heavy-duty vehicles, and the domestic main product is the Dachao Deutz engine.

● I use Deutz quite a lot around me. I have to say that I am oil-saving and I have to say I am oil-consuming, but I don’t agree with the dynamics.

Deutz as an improved model of the Weichai WD615 engine has better performance and fewer repairs.

● The single pumping country III truck requires the driver to go to a regular gas station for refueling, and pay attention to the fuel gauge to indicate timely refueling. Because the National III vehicle model requires a larger amount of oil in and out of the fuel supply system than the State II model, the amount of oil remaining in the fuel tank is too low, and the engine may be turned off due to air intake and it is difficult to start again. If users have fully understood these common-sense considerations before buying a car, they will get good results.

● The liberation truck can rewrite data to the ECU according to the specific vehicle driving and road condition information, improve the database, ensure the best balance of emissions, power, and fuel consumption, and ensure that the user's vehicle is in any situation according to the characteristics of the road condition and the use environment. The most reasonable power output, the most fuel-efficient.

It is better to use high-pressure common rail for light diesel engines, and it is better to use electronic control unit pumps for medium-sized diesel engines, and it is better to use electronic control unit pumps or pump nozzles for heavy-duty diesel engines.