Thermodynamic cycle-based maximum thermal efficiency prediction method for diesel engine

Abstract

The invention aims to provide a thermodynamic cycle-based maximum thermal efficiency prediction method for a diesel engine. The method comprises the steps: predicting the maximum thermal efficiency of the diesel engine according to parameters including a compression ratio, an explosion pressure ratio, a compression initial temperature, a compression initial pressure, a constant-volume pressurization ratio, a constant-pressure pre-expansion ratio, a constant-volume input heat ratio and a specific heat capacity ratio; predicting the highest heat efficiency of the diesel engine and a corresponding constant volume input heat ratio under a limited condition by deriving a function relation of a thermodynamic cycle heat efficiency expression of the diesel engine and combining with specific compression ratio and explosion pressure ratio limits, wherein the thermodynamic cycle of the diesel engine is particularly an ideal mixed heating cycle consisting of an adiabatic compression process, a constant-volume heating process, a constant-pressure heating process, an adiabatic expansion process and a constant-volume heat release process. According to the method, no experimental data is needed for checking and correcting the method, and the problem that an existing method for predicting the highest thermal efficiency of the diesel engine greatly depends on the experimental data is solved.

Description

technical field [0001] The invention relates to a diesel engine prediction method, in particular to a diesel engine thermal efficiency prediction method. Background technique [0002] Diesel engine is one of the most widely used power machinery in the world. As the most core index to characterize its power performance and economic performance, the thermal efficiency of diesel engine is of great significance. The thermal efficiency of a diesel engine is the ratio of the effective output work to its total input heat. The higher the thermal efficiency, the better the power performance of the diesel engine itself and the lower the fuel consumption. [0003] Predicting the maximum thermal efficiency of diesel engines can provide a theoretical direction for specific thermal efficiency optimization methods of diesel engines, so as to fully develop the thermal efficiency optimization potential of diesel engines. According to some existing literature, the current prediction of the h...

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Problems solved by technology

This type of method can meet the requirements in the prediction accuracy of the highest thermal efficiency, but for the diesel engine that is still in the design process, due to the lack of sufficient experimental data, it is difficult to carry out the prediction simulation of the highest thermal efficiency

In addition, due to the use of too many specific parameters of the diesel engine in the prediction of the simulation software, the prediction results are not universal and scalable, which brings inconvenience to the optimization of thermal efficiency

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