Two is not enough to play Volvo three-turbo engine analysis

　　 [Technical Channel of Quanzhou Yisheng Machinery Co., Ltd.] In this era of rampant turbines, even Japanese manufacturers that stick to naturally aspirated engines have begun to switch to the embrace of turbines, which also proves that the advantages of turbocharging technology are more obvious . However, the phenomenon of turbo intervention has always been a problem that plagues ordinary users and even car companies. Volvo, which has been deeply involved in the security field, revealed that they have found a way to solve the hysteresis. What is more worth looking forward to is the new Volvo 2.0T. The engine, equipped with three turbochargers, has a horsepower of at least 450PS. Today, let’s take a look at this three-turbo monster.

●Volvo Drive-E engine

　　 This engine belongs to Volvo’s Drive-E series. The meaning of E is high efficiency, environmental protection, Electric drive. It can be seen that the assembly and welding of many parts of the engine shown in the figure are relatively informal, and this will certainly not be a mass-produced model, but this one is still being debugged.

　　 On the exhaust side of the engine, two exhaust gas turbines connected in parallel are arranged, and the huge exhaust side also proves that it is a high-power turbine.

　　 On the intake side of the engine, there is the third turbine, and below is the electronic turbine driven by the motor. Compared with the exhaust gas turbine and the mechanical supercharging technology, the electronic turbine can eliminate the increase of the turbine. Turbine hysteresis, which is common in pressure, just compensates for the hysteresis caused by the large moment of inertia of the exhaust turbine. (About electric turbines, we have already explained in detail before, please click on the link: Will become mainstream in five years? The Jedi counterattack of electronic superchargers)

　　Okay, here comes the question, why does Volvo want Arrange the three turbines? What is the connection between them?

　　 The arrangement of the three turbines is roughly as follows: The electronic turbine is located on the side of the intake manifold, from the Suction Pipe (connected The pipeline between the air filter and the turbine body) connects a section of pipeline through the electronic turbine, and the air returns to the Suction Pipe after being pressurized; then the Suction Pipe is divided into two at the fork, and fresh air is sent to the exhaust side of the reverse side. In the two parallel exhaust gas turbines, they enter each cylinder respectively after being supercharged twice; among them, one turbine is driven by cylinders 1, 4 and the other turbine is driven by cylinders 2, 3.

　　 When the engine is at low speed, the bypass valve intercepts the air and enters the electronic turbine. At this time, the engine mainly relies on the electronic turbine to provide compressed air; as the speed increases, the exhaust gas The turbine begins to intervene, and the air compressed by the electronic turbine enters the exhaust gas turbine for secondary supercharging; the speed continues to increase, and the electronic turbine becomes a burden to the high-speed airflow. The airflow is blocked by the bypass valve outside the electronic turbine, and along The Suction Pipe flows to the exhaust gas turbine that has entered the state. This system solves the problem of poor low-speed intervention of large-size turbines by introducing electronic turbines, and can quickly start to compensate for the turbo lag of exhaust gas turbines when the pine oil accelerates again.

　　 In order to break out a horsepower of not less than 450PS, in addition to providing sufficient air, sufficient fuel is necessary. For this reason, Volvo has increased the pressure of the fuel injection system. By using the two high-pressure fuel pumps in V2 form and 90° opposite layout, the maximum pressure can reach 250Mbar. The use of direct injection technology in the cylinder also further improves the combustion. effectiveness.

　　Volvo revealed that this Drive-E series engine jointly developed by AVL, Denso and Polaris is fully capable of stably and reliably outputting 450PS horsepower. Services for large SUVs such as XC90.

　　 It is worth mentioning that the three-turbo technology is not Volvo's first thought. BMW has launched a similar three-turbo engine as early as 2012, which is a 3.0L The 6-cylinder diesel engine, model M550d, has a maximum power output of 280kW (375PS). Although the book data is not as good as Volvo's concept engine, BMW's vision is commendable. At the same time, Audi's RS5 TDI will also join the ranks of the three-turbo.

　　 Summary: Manufacturers have their own opinions on the issue of using natural aspiration or boosting, but as emission standards become stricter, small-displacement boosting will become an unstoppable trend. . The three-turbo technology has a certain impact on manufacturing costs, use and maintenance costs, but it is obviously helpful for power improvement and emission control. Look forward to Volvo's early implementation of this Drive-E engine for commercially available models.

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