Natural Gas Coaxially Graded Combustion Chamber Head Structure Adaptability Impact Study Pilot Stage Scheme

Nowadays,with the continuous development of technology,human society has high requirements and standards for environmental quality and the performance of gas turbines.As an important object for the military industry as well as for transportation and power generation,how to ensure low emissions of gas turbine combustion and the continuous upgrading of gas turbine physical products have become the focus of scientific research.There has been a lot of research on gas turbine combustion chambers worldwide,but the production of series combustion engines has become the focus of current gas turbine technology development in order to meet the needs of manufacturers.Among the three major components of a gas turbine,the most important part is the combustion chamber,and there are corresponding models of gas turbine combustion chambers to match the different powers of gas turbines.However,the problem of how to reasonably scale the head of gas turbine combustion chamber and how to improve the adaptability of the head after scaling and matching is an urgent problem to be solved.Therefore,based on the above research problems,this paper investigates the scaling law of natural gas turbines graded combustion chamber head,the method to improve the structural adaptability of the head after scaling and matching,and provides a reasonable scaling scheme for each research object in this paper through numerical simulation analysis,and the main research contents are as follows:(1)The head scaling criterion of natural gas turbines graded combustion chamber is given,and the flow field distribution and combustion characteristics of the combustion chamber under different scaling criteria are compared and analyzed.(2)The effects of fuel distribution strategy and fuel aperture diameter on the combustion chamber flow field distribution and combustion characteristics were investigated under the condition of combustion chamber head.The study shows that: by analyzing the effects of fuel aperture diameter and fuel classification strategy on improving head adaptation,it can be concluded that adjusting the fuel aperture diameter to make the fuel injection rate reach the ideal interval can significantly improve the head matching adaptation;by adjusting the fuel classification strategy,i.e.,appropriately reducing the central two-stage equivalent ratio can improve the combustion efficiency,and reducing the value class equivalent ratio while improving the efficiency can effectively control pollutant emissions.(3)Based on the scaling criteria given in this paper and the influence of fuel classification strategy and head fuel aperture size on the fitness under the unscaled condition,the scaling matching is carried out for different power gas turbine combustion chambers to study the flow field characteristics and combustion characteristics after matching,and the methods to improve the adaptation of head scaling matching are summarized by adjusting the fuel distribution and fuel aperture size.The study shows that in order to improve the combustion efficiency,reduce the emission and achieve the purpose of improving the head adaptation,it is necessary to appropriately increase the equivalent ratio of the main combustion stage II to fully release the combustion capacity of the main combustion stage II under the premise of avoiding flametout,and the method to improve the equivalent ratio of the main combustion stage II is to optimize the fuel distribution at all levels and select the appropriate fuel supply mode to achieve the purpose of improving the head adaptation.In terms of optimizing the fuel aperture,the fuel injection speed should be as similar as possible to the original head to improve the head fit.(4)Based on the same research method,we study the flow field characteristics and combustion characteristics of the matched gas turbine combustion chamber,and investigate the effects of array method,array spacing,and array rotation on improving the adaptability of head matching,and compare and analyze the best array solution,and adjust the fuel distribution to achieve the best array matching.The study shows that by matching multiple combustion chamber heads with a heavy-duty gas turbine combustion chamber according to a certain array method,and by comparing whether the head is arranged in the center or not,it is found that the combination of the head arranged in the center and the head arranged in the circumferential direction can effectively enhance the interaction between adjacent flames and make the flame fusion more fully;by changing the distance between adjacent heads,it is found that shortening the distance between adjacent heads will make the By changing the distance between adjacent heads,it is found that shortening the head reflow area will shorten the size of the head,which effectively intensifies the flame interaction and accelerates the flame fusion,and when the flame fusion interaction is more intense,the speed of temperature inhomogeneity changes faster,and the average temperature in the combustion chamber will be effectively controlled with the shortened distance to achieve the effect of reducing emissions;by changing the head rotation arrangement structure,it is found that the adjacent heads are arranged in the same rotation direction,which can Therefore,for multi-head arrays,the head layout using the center with circumferential arrangement,and within the effective interval,ensure the head rotation direction is consistent,and shorten the distance between adjacent heads as much as possible,can effectively control the Therefore,for the multi-head array,the head layout is centered with circumferential arrangement,and the head rotation direction is consistent within the effective interval,and the distance between adjacent heads is minimized,which can effectively control the temperature in the combustion chamber and enhance the flame fusion,thus achieving the research purpose of controlling the emission and improving the head suitability.