Vehicle Turbocharger System

The turbocharger system consists of a turbine which was driven by the exhaust gas, a center unit which connects the turbine and compressor, and an air compressor which compresses the air by the energy contained in the exhaust gas to increase the intake air density, thereby increasing the engine power and torque and achieving the goal of reducing the cylinder displacement and emissions. The technology utilizes the inertia force of the exhaust gas from the engine to propel the turbine in the turbine chamber, which in turn drives the coaxial shaft to rotate at a high speed, and pressurizes the air from the air intake system to pressurize it into the cylinder. When the engine speed increases, the exhaust gas discharge speed and the turbine speed also increase, which drives the compressor wheel and pressure more air into the cylinder. The more fresh air could burn more fuel and therefore increases the specific output power of the engine. The turbocharger system could have a maximum speed of 300,000 rpm and a temperature of more than 1050 Celsius degrees . Therefore, the thermal fatigue performance of the turbine system is very critial and the bearing system has to rotate at a very high speed with good lubrication and cooling.  The bearing system's moment of inertia are very critical to achieve good transient effects and efficiency.

The turbocharger uses the engine's high-temperature exhaust gas to propel the turbine wheel at high speeds up to 300,000 rpm. The turbine wheel is on the same axis as the compressor wheel. The high speed rotation of the turbine impeller drives the compressor impeller to rotate at the same high speed, which increases the air velocity and pressure through the compressor. Before the high-density, high-temperature compressed air enters the engine, it enters into the air cooler to cool it while achieving greater density and reduce the temperature. This allows the engine to increase fuel combustion efficiency with less energy consumption, resulting in higher output power. With the increasing use of high-pressure fuel injection systems, the use of turbochargers makes fuel combustion more thorough, efficient and clean. Turbochargers are often combined with a charge air cooler (CAC) to reduce the temperature of the compressed air to further increase the amount of compressed air intake.

Modern turbocharging systems incorporate many new technologies such as electronic wastegate control systems, dual vortex/dual runners, two-stage turbocharging systems, mixed-flow turbine blade design, and variable interface turbocharging systems (VGT/VNT) and even electronic turbines etc. to make the efficiency and response of the turbocharger system even more improved.

Advantages of Turbochargers

More fuel efficient – Turbocharged gasoline engines can increase fuel efficiency by  more than 25% compared to non-turbocharged gasoline engines of the same specification. Compared to non-charging gas engines, the same rated power of turbocharged diesel engines can increase fuel efficiency by more than 40%.

Better performance – Turbo boosts the engine's power and torque, improving vehicle response without sacriface transient response. In addition, it also protects the vehicle from power loss at high altitudes, bringing significant operational benefits to turbocharged trucks and off-road vehicles.

Cleaner and more environmentally friendly – Turbocharged engines maximize exhaust from the engine, make the engine burn cleaner, and reduce engine size without sacrificing performance while reducing CO2 and NOx emissions.

Turbocharging systems are widely used not only in diesel engines, but also in modern large, medium and small displacement gasoline engines. The same power/torque can significantly reduce the engine displacement to achieve the reduction of cylinder reduction efficiency, 0-60MPH acceleration time is significantly shorter than the naturally aspirated engine, fuel efficiency is higher - with the same specifications of non-turbocharged gasoline engine compared to turbocharged gasoline engines, fuel efficiency can be increased by up to 20%. The turbocharger system can be used with an electronic turbine to increase low-speed response, or it can be combined with an HEV drive system to work in optimal engine conditions to improve engine efficiency. 

The wastegate is an important part of the turbocharger and is used to unload excess exhaust gas to prevent stalls and coking from affecting the damage and life of the turbocharger. When the turbocharger is in operation, the control system determines the opening of the wastegate according to the needs of the engine, thereby determining the flow of gas to the turbine blades to achieve optimal performance of the turbocharger. When the exhaust gas energy exceeds the required value, the wastegate will open the waster gate poppet valve. OPS’ vaccum and electric wastegate technology uses precise opening control, advanced closed-loop control, and self-learning control strategy. It has the advantages of fast response, accurate control and high reliability, which can significantly increase the efficiency and torque of the traditional turbocharger. It has the anti-rattle cup spring to inprove the NVH performance and durabilty of the wastegate system.

OPS has successfully developed a 1.5T turbocharger, which is suitable for small and medium displacement gasoline engine engines. It has a wide working range, stable and reliable, and can significantly improve engine thermal efficiency, low speed torque, and working stability. The turbocharging technology is also suitable for fuel cell air compressors and unmanned drone engines.

The turbocharger uses a single volute radial flow turbine wheel and an electronically controlled wastegate system, which makes the structure of the turbocharger simple and reliable, with a compressor efficiency of up to 76% and a max. turbine efficiency of 72%. The volute design uses a topology optimization design to minimize weight reduction and meet thermal fatigue requirements. A fully floating dual bearing system and an axial bearing system are used to increase efficiency and hex bearing to mitigate sub-sync vibration. The compressor inlet is designed to prevent water trap and ice forimation in turbocharger. The weight and rotor moment of inertia are extremely optimized and reduced compared to the market competitors.