Diesel engine cylinder fuel-cut oil-saving system with twin-pressure charging system and pressure relief device

Abstract

The invention relates to a diesel engine cylinder fuel-cut oil-saving system with a twin-pressure charging system and a pressure relief device. The diesel engine cylinder fuel-cut oil-saving system comprises a multi-cylinder diesel engine, a first pressure charging systems, a second pressure charging system, a charge air cooler and a set of cylinder pressure relief device, wherein cylinders in the multi-cylinder diesel engine are divided into two groups according to the sequence of ignition: the first group of cylinders are connected with the first pressure charging system, while the second group of the cylinders are connected with the second pressure charging system; the cylinder pressure relief device is connected with the second group of the cylinders; and the charge air cooler is connected with the two groups of the cylinders through the first pressure charging system and the second pressure charging system respectively. The diesel engine cylinder fuel-cut oil-saving system can increase fuel injection capacity of one group of the cylinders by cylinder fuel-cut, thereby improving the quality of injection and atomization of the system, and improving thermal efficiency; two independent superchargers are adopted, so that interference on non-working cylinders on the superchargers when a supercharged diesel is in fuel cut can be overcome, thereby ensuring normal work of the working cylinders; and friction work of the non-working cylinders are greatly reduced by the cylinder pressure relief cylinder, thereby further reducing fuel consumption.

Description

technical field [0001] The invention relates to a fuel-saving system in the technical field of diesel engines, in particular to a cylinder-stop fuel-saving system of a diesel engine with a double booster system and a pressure relief device. Background technique [0002] When the engine is partially loaded, cutting off the oil supply of some cylinders and increasing the load of other working cylinders to improve the thermal efficiency of the engine is one of the effective measures for engine fuel saving. This technology is currently mainly used in gasoline engines, usually naturally aspirated multi-cylinder gasoline engines. This method has also been studied and used on diesel engines, but the fuel-saving effect obtained is very limited, so it has not been really applied in batches on supercharged diesel engines. [0003] Through literature search to prior art, it is found that Chinese patent CN86205030U "Diesel Engine Solenoid Valve Cylinder Stop Fuel-Saving Device" propose...

AI Technical Summary

Problems solved by technology

Its shortcoming is that it does not take into account the impact on the performance of the supercharger after some cylinders of the supercharged diesel engine stop working, as well as the loss of compression work and pumping gas, etc.

On the one hand, this is because when some cylinders of the supercharged diesel engine stop working, the work of the supercharger will be affected, the temperature difference between the exhaust gases of each cylinder will increase, and the possibility of surge will increase, which not only affects the reliability of the supercharger, but also Affects the combustion and thermal efficiency of the working cylinder

On the other hand, because the diesel engine does not have the throttling loss similar to the gasoline engine at low load, if there are no other measures to improve the mechanical efficiency of the engine at low load, cylinder deactivation will not achieve meaningful fuel saving effects

Therefore, the stability and reliability of turbocharger work, the deterioration of cylinder combustion after cylinder deactivation, and the low mechanical efficiency of the engine at low load are the main technical obstacles for turbocharged diesel engines to use cylinder deactivation technology to improve fuel economy.

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