具有可变几何喷嘴的增压器轴流涡轮热力计算方法

本文提出具有可变几何喷嘴的增压器轴流涡轮热力计算方法。引入三个脉冲系数将脉冲涡轮按等压涡轮计算。给定通流部分尺寸,利用可变几何喷嘴来满足所驱动压气机和涡轮的配合。考虑各部实际损失,采用吴仲华燃气热力性质表迭代计算求出反动度、喷嘴出气角和喉口面积。可给定废气初温时迭代所需的初压或给定初压时迭代所需的初温,并算出涡轮当量通流面积。计算结果表明迭代计算是收敛的,算出的喷嘴喉口面积与实际相符。

A Method for Thermodynamic Calculation of the Axial Flow Turbocharger Turbine with Variable Geometry Nozzle

This paper presents a method for thermodynamic calculation of the axial flow turbocharger turbine with variable geometry nozzle. With the quotation of three pulse coefficients, the fluctuating turbine is regarded as isobaric turbine. As the turbine flow passages are given and by means of the variable geometry nozzle, the matching between compressor and turbine can be satisfied. Taking advantage of the gas table and the practical losses, the reaction, the outlet flow angle and the throat area of nozzle can be calculated by means of iteration. As the entry pressure or temperature of gas is granted, the necessary entry temperature or pressure of gas can be obtained through iterating calculation, The equivalent area of turbine flow passages is evaluated. The calculations indicate that the iterating calculation is converged and the calculated throat area of nozzle accords with practicality.