Supercharged diesel engine system based on EGR (exhaust gas recirculation) high pressure chamber

Abstract

The invention aims to provide a supercharged diesel engine system based on an EGR (exhaust gas recirculation) high pressure chamber. The supercharged diesel engine system comprises a diesel engine and a turbosupercharger, wherein a turbine of the turbosupercharger is connected with an exhaust manifold of each steam cylinder of the diesel engine, and a compressor of the turbosupercharger is connected with an air inlet manifold of each steam cylinder through an air inlet main pipe; and the supercharged diesel engine system also comprises the EGR high pressure chamber and an EGR valve, wherein the EGR high pressure chamber is communicated with each exhaust manifold through a one-way stop valve, the EGR high pressure chamber is communicated with an exhaust main pipe through a discharge valve and is communicated with an air inlet main pipe through the EGR valve. The supercharged diesel engine system provided by the invention effectively utilizes the exhaust pulse energy, high pressure waste gas opens up a one-way isolating valve, waste gas is injected into the high pressure chamber, so the waste gas pressure in an EGR chamber is improved, and meanwhile, the discharge valve of the high pressure chamber guarantees a constant pressure in a cavity body, and finally the waste gas can smoothly return to the air inlet main pipe, and the NOx discharge of the diesel engine is lowered.

Description

technical field [0001] The invention relates to a diesel engine, specifically a diesel engine with a turbocharger. Background technique [0002] Theoretical research on EGR technology began in the 1960s and was first applied to gasoline engines. Since the 1970s, some foreign automakers have turned their research targets to diesel engines. Up to now, the power industry of various countries has increasingly used EGR technology to reduce nitrogen oxide emissions to meet the limit value stipulated by regulations. Its basic principle is to use the exhaust gas to circulate into the cylinder, on the one hand to dilute the oxygen concentration in the cylinder and inhibit the N2 oxidation reaction; on the other hand, to use the high specific heat capacity of the inert gas in the exhaust gas to reduce the combustion rate to achieve the purpose of reducing NOx emissions. [0003] When the supercharged diesel engine works in the medium-to-high load area, the outlet pressure of the comp...

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Problems solved by technology

[0003] When the supercharged diesel engine works in the medium-to-high load area, the outlet pressure of the compressor is basically greater than the exhaust pressure in front of the turbine. The pressure is lower than the intake pressure, which makes it difficult for the exhaust gas to flow back into the intake pipe, and even causes the intake pressure to flow back into the exhaust pipe, causing the diesel engine to have adverse phenomena such as reduced output power, increased fuel consumption, and unstable operation.

[0004] At present, some diesel engine EGR systems eliminate the influence of intake and exhaust pressure differences by installing structures such as throttle valves and Venturi tubes, but in actual use, not only will the efficiency of the compressor be reduced, and the normal use of the supercharger will be affected. It will reduce the intake pressure of the diesel engine, affect the power output, and increase fuel consumption

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