Research On The Influence Of Icing On Intake Components Of Marine Gas Turbine

Due to factors such as fast airflow velocity,large rate of flow,and high air humidity,the icing phenomenon of marine gas turbine on intake components is prone to occur in the cold marine environment.The icing of intake components will lead to the reduce of flow area of the gas turbine,increase the inlet nonuniformity of the compressor,and decrease the working efficiency of the compressor.In severe cases,the falling of the ice layer on the intake components will cause mechanical damage to the compressor blades and affect the safe operation of the gas turbine.In order to understand the icing process of gas turbine intake components,master the influence of icing of intake components on the flow field,and to predict the temperature of icing of intake components under different conditions,this paper used a numerical simulation method to study the icing process of marine gas turbine intake components.This paper has carried out the following work:1.The two-dimensional icing calculation of NACA0012 airfoil at various ambient temperatures is carried out by using the time multi-step method.The error analysis of the calculated icing shape is carried out by introducing the icing characteristics and aerodynamic characteristic parameters of the airfoil,which provided the method validation for the icing numerical simulation of intake components of marine gas turbine.2.The icing simulation was carried out for the blade profile of 50% blade height of the inlet guide vane of a certain marine compressor and the marine gas turbine center deflector with inlet structure.The influence of icing factors on icing of intake components of marine gas turbine was established,and the flow field characteristics of the icing blade profile and center deflector were analyzed.3.Combined with BP neural network,the mathematical model of intake parameters and icing temperature is established to predict the icing temperature of intake center deflector.The icing deposition of marine gas turbine intake components is mainly concentrated near the stagnation area of components.Within the range of variables studied in this research,differences in air flow velocity,droplet median volume diameter,liquid water content,ambient temperature,and freezing time all affect the icing shape and droplet collection coefficient of the blade profile and the center deflector.Among them,the upturned glaze ice when frozen above the freezing temperature will seriously affect the airflow uniformity at blade profile outlet and increase the total pressure loss.At the same time,when the ice layer on the surface of the center deflector touches the compressor flow channel,it will also affect the velocity field in the flow channel.Finally,a back propagation neural network can be used to form a set of preliminary prediction codes for the icing temperature of the center deflector of marine gas turbine.After inspection,the icing temperature value predicted by the code has certain credibility.