Blue Efficiency Mercedes-Benz Blue Efficiency Environmental Protection Technology Analysis

New energy has become a trend in the automotive industry. To seize the opportunity, various manufacturers have also invested in the research of pure electric technology and fuel cell technology. However, new energy vehicles will never become a trend immediately, and new energy is just a general term. No one can conclude which driving technology will dominate the future. Different from some domestic manufacturers who are betting everything on one thing, Mercedes-Benz uses the BlueEFFICIENCY environmental protection strategy to explain its understanding of the zero-emission path.

BlueEFFICIENCY is not a single technology, but a general term for a series of environmental protection technologies of Mercedes-Benz. This comprehensive environmental protection technology includes optimizing internal combustion engines, improving combustion efficiency through hybrid technology, and achieving zero-emission driving through batteries and fuel cell vehicles. It is also a step-by-step description of Mercedes-Benz's zero-emission strategy. By 2010, 85 Mercedes-Benz models have used this technology, including C180K, E200, E260 and other models entering China. These models will have the "BlueEFFICIENCY" logo on the fenders.

BlueEFFICIENCY First Step:

Improving fuel efficiency of internal combustion engine vehicles

At present, many new energy vehicles have been put into mass production. However, in terms of the overall environment, internal combustion engines will still dominate for a long time. It is more practical to tap the potential of internal combustion engines in the current environment. The first step of the BlueEFFICIENCY strategy includes a plan to improve the technology of existing internal combustion engines, and the representative work is the CGI engine installed in the domestic C-class and E-class.

Direct injection system of the engine

Compared with the mechanical supercharged engines that Mercedes-Benz used to use, the biggest advantage of the turbocharged direct injection engine lies in the direct injection system.

Ordinary gasoline engines usually spray gasoline into the intake manifold, and then form a mixed gas with air before entering the cylinder for combustion. Since there is a certain distance between the fuel injector and the cylinder, the concentration of the mixed gas is easily affected by the airflow and valve switching, making it difficult to achieve the theoretical air-fuel ratio. Direct injection engines can solve this problem very well. Through precise computer control, the fuel is directly injected into the cylinder in the form of high pressure, achieving precise control of the air and gasoline mixing ratio and injection timing, allowing the mixed gas to burn more fully and improve energy efficiency.

Engine Thermal Management System

In addition, the engine also uses a heat management system that prevents coolant from passing through the cylinders when the engine is cold, allowing the engine combustion chamber to heat up quickly when needed, further reducing fuel consumption.

According to official data, the E260CGI is equipped with Mercedes-Benz's 1.8L all-aluminum CGI turbocharged direct-injection engine, with a power output of 150kW and 310Nm. It can accelerate from 0 to 100 km/h in just 7.8 seconds, and its corresponding fuel consumption is 7.8 liters per 100 km. It has excellent performance in terms of fuel consumption and power.

Modify the design through multiple tests to reduce air resistance

In addition to improving the engine, BlueEFFICIENCY comprehensive environmental protection technology also reduces energy loss and improves fuel efficiency through a series of means such as reducing weight, reducing air resistance, reducing friction resistance, energy management, and energy recovery. It saves where possible and the detailed measures are very well implemented.

Low rolling friction tires can help reduce fuel consumption

The energy-saving power steering pump is one of the more typical energy-saving components used in the Mercedes-Benz E-Class (details, pictures, quotes). Conventional power steering oil pumps always run at full power during the operation of the car, while energy-saving power steering pumps can automatically adjust the power of the steering oil pump according to the driving conditions. For example, when driving in a straight line, the electronic control module reduces the operating power of the power steering oil pump to the minimum, and when the driver turns the steering wheel, the flow of the power steering oil pump increases spontaneously, and adjusts the operating power of the oil pump according to the current steering angle, engine speed and vehicle speed.

Power steering pump

Of course, this meticulous attitude also makes the cost of car manufacturing increase a lot, and whether the complex operating mechanism will lead to the instability of the sound system remains to be tested.

BlueEFFICIENCY Step 2:

Practical hybrid technology

Before the zero-emission era arrives, hybrid power is seen as one of the main technical forms in the transition period. Facing Lexus' hybrid offensive, Mercedes-Benz has also launched its own hybrid products in the BlueEFFICIENCY strategy, including mild hybrid, strong hybrid and other forms.

Currently, the only BlueEFFICIENCY hybrid product available in China is the S400 HYBRID, a lithium-ion battery hybrid vehicle developed based on the S350.

Hybrid Powertrain

Different from the S350, the S400 HYBRID has made improvements in power transmission, including a modified 3.5-liter V6 gasoline engine, an auxiliary electromagnetic engine, a 7G-TRONIC seven-speed automatic transmission specially equipped for the hybrid module, necessary electronic operation and control components, transformer, and high-voltage lithium-ion battery.

Electric Motor

In the compact hybrid module of the S400 HYBRID, the disc-shaped electric motor plays the dual role of starter and generator. During the acceleration phase, the electric motor intervenes in the power assistance work, providing the 6-cylinder gasoline engine with a maximum additional torque of 160Nm. During the braking process, the electric motor will act as a generator, which can recover the kinetic energy lost during the braking process.

Lithium-ion battery

The energy recovery of the S400 HYBRID is divided into two consecutive stages: in the first stage, when there is no braking effect, the electric motor acts as a generator and is ready to recover energy at any time. Once the driver gently presses the brake pedal, the second stage begins, and the generator output power will increase proportionally as the braking deepens. At this time, if the brakes are pressed hard, sensitive drivers can clearly perceive the resistance brought by the engine braking, and the energy generated during braking will be recovered.

The S400 screen displays the working status of the hybrid system

The S400 HYBRID hybrid module also includes an ECO automatic start-stop system. When the vehicle coasts to a stop at a speed of no more than 15 km/h (for example, before stopping at a traffic light), the automatic start-stop system automatically shuts down the engine until the vehicle is started again. As soon as the driver releases the brake pedal or presses the accelerator pedal, the electric motor immediately restarts the engine.

Because it is a mild hybrid, the electric motor power is not enough to drive the vehicle alone, and the battery capacity is also quite limited, so the hybrid module only plays an auxiliary driving role. Perhaps it is precisely because of the compression of functions that the size of the battery system is well controlled, and the additional weight of the entire system is only 75 kilograms. Judging from the price of the S400 HYBRID, this hybrid system is also acceptable to people.

S500 PLUG-IN Plug-in Hybrid

Overseas, Mercedes-Benz hybrid models that have been released include plug-in hybrid and diesel hybrid, among which the S500 hybrid version adopts plug-in hybrid. Driven by the battery, the S500 hybrid can travel 30 kilometers in full electric drive, with a standard fuel consumption of only 3.2L/100km and carbon dioxide emissions of only 74g/km. Although it consumes less, the performance of the S 500 hybrid has not shrunk at all under the joint action of the V6 gasoline direct injection engine and the hybrid module, and its acceleration time from 0 to 100km/h is only 5.5s!

Hybrid power is by no means exclusive to automobiles. Diesel engines, which inherently have high fuel performance, can more easily achieve good fuel-saving effects with the help of hybrid power technology.

As a representative model of Mercedes-Benz diesel hybrid, the E 300 BlueTEC HYBRID is equipped with a hybrid module equipped with a 2.2L four-cylinder diesel engine. It consumes only 4.1L of fuel per 100 kilometers, and the electric engine it installs can also enable it to achieve zero-emission driving relying on pure electricity.