Diesel engine combustion heat release rate prediction method based on evaporation process

Abstract

The invention belongs to a prediction method, and particularly relates to a diesel engine combustion heat release rate prediction method based on an evaporation process. The method comprises the following steps: step 1, determining a formula; 2, performing normalization conversion on the heat release rates of the two modes; step 3, calculating normalized fuel consumption rates of the two modes; step 4, calculating evaporation rates of the two modes; and 5, calculating the total fuel evaporation rate. The method has the remarkable effects that (1) the combustion rate is controlled by the evaporation rate, so that the real combustion process is restored to a great extent; (2) the actual time logic relationship of oil injection, evaporation and combustion is reproduced; and (3) the method can be used for rapidly predicting the combustion heat release rate of the diesel engine under various working conditions.

Description

Technical field [0001] The present invention is a predictive method, and in particular, the present invention relates to a method of combustion release rate prediction method based on a diesel engine based on an evaporation process. Background technique [0002] In the study of the diesel combustion system, the use of the combustion model is very common, which can be used to simulate the relevant physical quantity of the combustion release law and product before the R & D real machine, thereby predicting and optimizing the performance of combustion system. It can greatly reduce the funds and time costs of the development of the actual combustion system. [0003] The combustion model of the diesel engine is mainly divided into two categories, one is a non-predictive model, most of which are zero-dimensional models, i.e., the physical quantity in the cylinder, such as a WIEBE combustion model, and the advantage is simple, but it is only given. The control function of the exothermic...

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Problems solved by technology

[0003] Diesel engine combustion models are mainly divided into two categories, one is non-predictive models, most of which are zero-dimensional models, that is, the physical quantities in the cylinder are calculated with uniform distribution, such as the Wiebe combustion model, which has the advantage of simple calculation, but it only gives The control function of the heat release rate, and all coefficients need to be set artificially, which makes it only applicable to the existing experimental data, so that the coefficients can be calibrated, so the function of prediction cannot be realized; the other is the prediction model , some of which are zero-dimensional models, such as the Watson combustion model, whose coefficients can be expressed by semi-empirical formulas with certain physical meanings, thus realizing the prediction of heat release rates under various operating conditions, but it ignores the real combustion The time logic relationship of fuel injection, evaporation and combustion in the process, so the combustion process cannot be accurately reproduced, and the calculation accuracy is low

The other part is the quasi-dimensional model, that is, the physical quantities in the cylinder are calculated with uneven distribution, such as the Guangan Bozhi and Cummins combustion models, this method is to calculate the physical quantities in the cylinder, and the physical quantities in each sub-district are still uniformly distributed. The mathematical model reproduces the real combustion process. This prediction method is more accurate, but the operation is extremely complicated

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