Diesel Oil Mixed Analysis of SAIC Chase MAXUS Xuanyuan Power

　　[car home Engine Analysis] Today, with the increasing popularity of electric vehicles, many manufacturers are still insisting on the development of internal combustion engines. After all, in the domestic and even global markets, oil vehicles still have an irreplaceable position in many application scenarios. Speaking of SAIC MAXUS, many consumers may immediately think of their hard-core SUVs, pickup trucks and RV products, and today it is from SAIC MAXUS Xuanyuan Power that we want to talk about.

　　Speaking of diesel engines, in the traditional cognition of many consumers, diesel engines have the advantages of durable leather, high torque, low fuel consumption, etc., and are suitable for use on complex roads, climbing hills, heavy loads, etc., so they are also the first choice for many hard-core off-road vehicles. However, noise, pollution and other problems have also discouraged many consumers. What changes can diesel engines make in the hands of SAIC Chase engineers?

What is SAIC Chase Xuanyuan Power Technology?

　　The brand-new SUV territory of SAIC Chase MAXUS is equipped with the first diesel light hybrid power technology in Asia, which combines a 2.0T SAIC π Bi-Turbo double supercharged diesel engine, a ZF 8AT automatic transmission and a 48V hybrid architecture. The technology is named "SAIC Chase Xuanyuan Power Technology", and this diesel engine has also won the reputation of "Top Ten Engines of China Heart" in 2020.

2.0T SAIC π Bi-Turbo Dual Supercharged Diesel Engine

　　As one of the top ten engines of the year, this 2.0T twin-supercharged engine has its own good skills, and it is also the core of this Xuanyuan power. Let’s take a look at what "black technologies" it has.

　　The vehicle adopts WGT+VGT two-stage turbocharger, which is adjusted by three vacuum valves to realize the free switching between high and low pressure stages, and has three working modes, namely, the low-speed stage uses small blades, the middle-speed stage uses two blades at the same time, and the high-speed stage uses large blades, which improves the engine efficiency. When the engine speed is 1000rpm, the turbine will intervene and reach the maximum torque output at 1500rpm, which will increase the low-speed torque and power of the vehicle by 15% and 30%.

　　The water-air intercooler adopts water cooling and air cooling at the same time. Under the same air-fuel ratio, the engine power will increase by 3%~5% for every 10℃ drop in the temperature of pressurized air.

　　At the same time, this engine also applies the intelligent single-axis continuous variable vortex control valve for the first time. When the engine is in high working condition, the control valve will open a relatively flat intake port, so that air can enter the engine cylinder quickly and smoothly. When the engine is under low load, the control valve will open the air passage with spiral cross section to help the air entering the engine cylinder produce better vortex effect, so that the pressure difference of each cylinder can be less than 3%, and the air intake can be more uniform, thus making the combustion of each cylinder of the engine stable, achieving smoother power output, and reducing the emission of particles and carbon monoxide and fuel consumption.

　　This diesel engine adopts a two-stage variable oil pump, which can adjust the oil pump flow in real time according to different speed loads while meeting the oil pressure demand. Low-pressure mode is adopted at medium-low speed and medium-low load; When there is a high speed and high load demand, the high pressure mode is adopted. Through adjustment, the oil pump can run at the lowest energy consumption, thus reducing fuel consumption. Through the NEDC (New European Cycle Test) cycle test, the fuel consumption of the whole vehicle can be reduced by 2~3%;

　　In addition, this diesel engine is equipped with a double-shaft balancing mechanism and a double-loop EGR system, in which the balancing shaft is asymmetrically arranged to balance the engine covering torque, which greatly reduces the second-order vibration, makes the engine run more smoothly, and also reduces vibration and noise. The dual-loop EGR system can reduce the warm-up time, reduce fuel consumption and improve the heating effect of air conditioning. (EGR is the full name of exhaust gas recirculation system. By re-injecting some exhaust gas into the engine cylinder, the combustible mixture is diluted and the combustion efficiency is reduced, so as to achieve the purpose of controlling the working temperature of the engine, reducing Nox emission and reducing urea consumption. )

　　In addition to the above, this diesel engine also adopts Bosch’s ultra-high pressure fuel injection system, which can obtain more accurate fuel supply control, and crankshaft offset technology, which can effectively reduce the running noise and wear of the engine piston. At the same time, a number of NVH optimizations have been carried out.

48V light mixing system

? The 48V light mixing system of the vehicle adopts Valeo 48 BSG motor, with special bidirectional tensioner, and the gear train speed ratio is as high as three times, which further amplifies the output torque of 48V BSG and effectively improves the low-speed torque characteristics of diesel power. When the 48V battery is charged, the engine is started by BSG, and the vehicle starts more smoothly, the starting time is shortened from the traditional 0.6 seconds to 0.3 seconds, and the starting noise is reduced by 10-15 dB. With the assistance of the motor, the torque of the power system is increased by more than 30%, and the starting acceleration of the vehicle below the medium and small throttle of 30%-50% is increased by more than 33%; 0-100km/h acceleration time is shortened by 0.4 seconds.

　　In addition to performance, fuel economy has been further improved. Under high-speed working conditions, the surplus torque of the engine drives the 48V motor to charge and store energy. The fuel consumption under WLTC can be saved by 8%, while Nox emission can be reduced by more than 50% in RDE test at most.