Two-stage electric control pneumatic pressurization system with adjustable turbine bypass valve and variable altitude control method of two-stage electric control pneumatic pressurization system

Abstract

A two-stage electric control pneumatic supercharging system with an adjustable turbine bypass valve comprises a high pressure-stage turbocharger, a low pressure-stage turbocharger, a high pressure-stage intercooler, a low pressure-stage intercooler and an adjusting device. The high pressure-stage turbocharger and the low-pressure stage turbocharger comprise a high-pressure stage turbocharger and alow-pressure stage turbocharger which are connected in series, the high-pressure stage turbocharger comprises a high-pressure stage bypass valve turbine and a high-pressure stage air compressor, andthe low-pressure stage turbocharger comprises a low-pressure stage bypass valve turbine and a low-pressure stage air compressor; the high-low pressure stage intercooler is composed of a high-pressurestage compressor intercooler and a low-pressure stage compressor intercooler, and the adjusting device comprises a vacuum pump, an electromagnetic valve, a pneumatic actuator, a bypass valve and a connecting pipeline. According to the variable-altitude control method of the system, the variable-altitude full-working-condition supercharging pressure adjustment of the engine can be realized by controlling the opening degree and the opening and closing of each valve, utilizing the calibrated supercharging pressure and the air pressure MAP in a pneumatic actuator and adopting two modes of closed-loop feedback and open-loop feedforward for adjustment according to the working conditions of the engine.

Description

technical field [0001] The invention relates to the technical field of engine supercharging, in particular to a two-stage electronically controlled pneumatic supercharging system with an adjustable turbine bypass valve and a variable altitude control method thereof. Background technique [0002] The turbocharger uses the pressure of the exhaust gas from the engine to drive the turbine, and then uses the torque of the turbine to rotate the compressor to push the intake air into the engine to increase the output power. As the altitude rises, the atmospheric pressure decreases, the supercharging capacity of the supercharger decreases, and the engine power decreases accordingly. In order to restore the power of the engine at an altitude of 5000m to reach the target of 90% of the plain power, the boost pressure of the compressor is at the maximum torque point to In the range of the calibration points, at least the level of the plain supercharging pressure can be reached or even h...

AI Technical Summary

Problems solved by technology

At present, adjustable supercharging mainly includes variable section supercharging and adjustable turbocharging with turbine bypass valve. The theoretical advantages of variable section supercharging are obvious, but the complexity, reliability and volume of its structure limit its application. Turbine bypass valve Compared with the variable cross-section supercharger, the valve-adjustable supercharger is smaller in size and has higher reliability. It is more suitable to use a two-stage turbine bypass valve-adjustable supercharger for the plateau environment.

[0003] At present, most of the two-stage supercharging variable altitude control methods are aimed at the steady-state working conditions at a fixed altitude. When the matching point of the two-stage supercharging design is selected as an engine in a plain area, when operating in a plateau area, due to the decrease in air density, the engine power will also decrease accordingly.

When the matching point of the two-stage supercharging design is selected as the engine in the plateau area, when it is operated in the plain area, the emission performance of the engine at low speed and the economy at high speed will be seriously reduced

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