CN-121972685-A - Flame tube cooling hole design and manufacturing method based on temperature field constraint and additive manufacturing

CN121972685ACN 121972685 ACN121972685 ACN 121972685ACN-121972685-A

Abstract

The invention discloses a flame tube cooling hole design manufacturing method based on temperature field constraint and additive manufacturing, which comprises the steps of obtaining flame tube surface temperature distribution data through full-working-condition thermal simulation, carrying out cooling hole optimization design of a flame tube according to a temperature threshold value and thermal gradient distribution based on the flame tube surface temperature distribution data, generating a preliminary cooling hole optimization distribution scheme, reintroducing the preliminary cooling hole optimization distribution scheme into a simulation environment, verifying the heat dissipation effect of the flame tube, comparing temperature distribution differences of the flame tube surface before and after optimization, adjusting the cooling hole distribution scheme until a target index is met, outputting a final cooling hole optimization distribution scheme, and adopting a laser powder bed melting additive manufacturing process according to the final cooling hole optimization distribution scheme to directly form cooling holes in the forming process of the flame tube. The invention can realize the accurate optimization of the layout of the cooling holes of the flame tube and the integrated manufacture of the cooling holes of the flame tube.

Inventors

HE SHUAI
HUANG BINGFA

Assignees

上海和兰动力科技有限公司

Dates

Publication Date: 20260505
Application Date: 20260205

Claims (10)

1. The flame tube cooling hole design and manufacturing method based on temperature field constraint and additive manufacturing is characterized by comprising the following steps of: s1, acquiring flame tube surface temperature distribution data through full-working-condition thermal simulation; S2.1, carrying out optimal design of cooling holes of the flame tube according to a temperature threshold and thermal gradient distribution based on the flame tube surface temperature distribution data obtained in the step S1, and generating a preliminary optimal cooling hole distribution scheme; s2.2, reintroducing the preliminary cooling hole optimizing distribution scheme in the step S2.1 into a simulation environment, verifying the heat dissipation effect of the flame tube, comparing the temperature distribution differences of the surfaces of the flame tube before and after optimizing, adjusting the cooling hole distribution scheme until the target index is met, and outputting a final cooling hole optimizing distribution scheme; S3, according to the final cooling hole optimal distribution scheme in the step S2.2, adopting a laser powder bed melting additive manufacturing process, and directly forming cooling holes in the forming process of the flame tube.
2. The method for designing and manufacturing a cooling hole of a flame tube based on temperature field constraint and additive manufacturing according to claim 1, wherein the step S1 comprises the following sub-steps: s1.1, setting working conditions, namely respectively establishing a heat flow boundary condition and an internal heat source distribution model of the flame tube under corresponding operation states by combining typical operation states of gas turbine equipment; S1.2, establishing a model of the flame tube, namely establishing a three-dimensional geometric model of the flame tube based on three-dimensional geometric modeling software, and introducing physical processes of gas flow, heat conduction, convection heat transfer and radiation heat transfer based on a computational fluid dynamics CFD and a finite element FEM method, wherein specific numerical values of the physical processes of gas flow, heat conduction, convection heat transfer and radiation heat transfer are obtained through the heat flow boundary conditions and the internal heat source distribution model established in the step S1.1; S1.3, simulation output, namely obtaining a temperature distribution cloud picture of the surface of the flame tube through numerical calculation, and obtaining temperature gradients of different areas of the surface of the flame tube and heat flux distribution data of the surface of the flame tube according to the temperature distribution cloud picture of the surface of the flame tube, wherein the temperature field of the surface of the flame tube is set to be T (x, y), the temperature range of the whole area of the flame tube is counted to be Tmin and Tmax, and the normalized temperature of the surface of the flame tube is defined to be theta (x, y) = (T (x, y) -T min )/(T max −T min ), wherein theta (x, y) e [0, 1].
3. A method of designing and manufacturing a cooling hole for a burner tube based on temperature field constraint and additive manufacturing according to claim 2, wherein step S2.1 comprises the sub-steps of: s2.1.1, designing cooling holes, namely reducing the hole spacing of the cooling holes and increasing the aperture in a high-temperature area of the surface of the flame tube, increasing the hole spacing of the cooling holes and reducing the aperture in a low-temperature area of the surface of the flame tube, and performing distribution design of the cooling holes in a transitional mode in a medium-temperature area of the surface of the flame tube; S2.1.2, designing a variable period distribution strategy of the cooling holes based on a design principle of the cooling holes: S2.1.3, generating a preliminary cooling hole optimal distribution scheme based on a cooling hole variable period distribution strategy and based on a temperature threshold value and thermal gradient distribution.
4. The method for designing and manufacturing the cooling holes of the flame tube based on the temperature field constraint and additive manufacturing of claim 3, wherein in the step S2.1.1, in the design principle of the cooling holes, the optimization basis of the cooling holes is specifically that a heat flux distribution function q (x, y) of the surface of the flame tube is obtained according to heat flux distribution data of the surface of the flame tube, a target cooling efficiency function eta (x, y) of the surface of the flame tube is defined, a mapping relation between the hole spacing of the cooling holes on the flame tube and the heat dissipation capacity of the flame tube is established by adopting the heat flux distribution function q (x, y) and the target cooling efficiency function eta (x, y), a mapping relation between the hole diameter of the cooling holes on the flame tube and the heat dissipation capacity of the flame tube is established, and the optimal hole spacing and the optimal hole diameter of the cooling holes in different areas of the flame tube are determined through iterative simulation.
5. A method for designing and manufacturing a cooling hole of a flame tube based on temperature field constraint and additive manufacturing according to claim 3, wherein the step S2.1.2 specifically comprises: Let the hole spacing of the cooling holes be denoted as d and d be related to θ (x, y), then d (θ) =d min +(1-θ) p ×(d max -d min , where p represents the engineering constant and p+.1, then d=d min when θ=1 and d=d max when θ=0; Let the aperture of the cooling hole be denoted as a and a be related to θ (x, y), a (θ) =a min +θ q ×(a max -a min , where q represents the engineering constant and q is Σ1, a=a max when θ=1 and a=a min when θ=0.
6. The method for designing and manufacturing the cooling holes of the flame tube based on temperature field constraint and additive manufacturing according to claim 3, wherein the step S2.2 is characterized in that the preliminary cooling hole optimization distribution scheme in the step S2.1.3 is reintroduced into the simulation environment of the computational fluid dynamics CFD and finite element FEM method, the heat dissipation effect of the flame tube is verified, the temperature distribution difference of the surfaces of the flame tube before and after optimization is compared, the hole spacing and the hole diameter of the cooling holes are adjusted until the target index is met, and the final cooling hole optimization distribution scheme is output.
7. The method for designing and manufacturing the cooling hole of the flame tube based on the temperature field constraint and additive manufacturing according to claim 1 or 6, wherein in the step S2.2, the target index is specifically that the highest temperature of the surface of the flame tube after optimization is reduced by DeltaT 1 , and the uniformity of the temperature field of the surface of the flame tube after optimization is less than 5 percent compared with the flame tube before optimization.
8. The method for designing and manufacturing the cooling hole of the flame tube based on temperature field constraint and additive manufacturing according to claim 5, wherein in the step S3, laser in the laser powder bed melting additive manufacturing process is generated by a single-mode fiber laser, the laser power is 200W-500W, the light path of the laser is sequentially collimated, electric zooming and beam expanding, galvanometer scanning and f-theta field lens, the diameter of an online continuously adjustable focal spot supported by a zooming mechanism of zooming and beam expanding is controlled to be 60 mu m-150 mu m, the focal length is automatically focused along with the layer height in the forming process of the flame tube, and a processing strategy is automatically distributed according to the area label of a design area or a geometric field d (theta) and a (theta) deduced by temperature driving design.
9. The method for designing and manufacturing the cooling hole of the flame tube based on the temperature field constraint and the additive manufacturing according to claim 8, wherein in the step S3, the machining strategy is specifically as follows: A slight positive defocusing mode is adopted in the thin wall and hole edge area, the defocusing amount is controlled to be between +0.05mm and +0. mm, specifically, small light spots, low line energy density and multiple contours are adopted in the thin wall and hole edge area for forming, wherein the hole edge area is an area which is less than or equal to 0.35mm away from the hole edge; the large-area filling adopts a large light spot and high coverage rate mode.
10. The method for designing and manufacturing a cooling hole of a flame tube based on temperature field constraint and additive manufacturing according to claim 1, wherein the following steps are further included after the step S3: And S4, verifying the quality and the size of the formed cooling holes, and calibrating the flow of the cooling holes.

Description

Flame tube cooling hole design and manufacturing method based on temperature field constraint and additive manufacturing Technical Field The invention belongs to the technical field of gas turbine equipment, and particularly relates to a flame tube cooling hole design and manufacturing method based on temperature field constraint and additive manufacturing. Background The flame tube is used as one of the core components of combustion chambers in aeroengines and gas turbines, and has the main functions of accommodating and stabilizing combustion reactions and uniformly guiding high-temperature gas generated by combustion into a turbine part. In the actual operation process, the flame tube is in an extreme thermal environment and a high-pressure working condition for a long time, and the local temperature can reach thousands of degrees celsius, so how to effectively improve the thermal management capability of the flame tube, reduce the structural thermal load of the flame tube and prolong the service life of the flame tube through reasonable cooling hole design and processing technology is one of the key technical problems in the field of manufacturing combustion chambers in aeroengines and gas turbines. In the conventional manufacturing process, the cooling holes of the flame tube are usually formed by a subsequent mechanical drilling method, but the method has the defects of 1) limited machining precision, particularly large size error and poor surface quality of the cooling holes when aiming at the flame tube with a complex profile and the small-diameter cooling holes, 2) insufficient thermal management, particularly uneven heat dissipation performance of the flame tube due to the fact that the cooling hole distribution of the flame tube cannot correspond to the actual temperature field of the flame tube, 3) low manufacturing efficiency, and particularly prolonged manufacturing period due to the fact that the cooling holes are machined and post-processed repeatedly. Patent CN115106716a discloses a flame tube repairing method based on additive manufacturing technology, which solves the problem of deformation and cracking generated in the process of manufacturing and repairing the additive of the flame tube, but does not relate to the optimal design of cooling holes, and cannot solve the problem of uneven cooling performance of the flame tube. Patent CN115475958a discloses a method for manufacturing a flame tube based on a laser powder bed melting additive manufacturing technology, and the method adopts a unique supporting and allowance adding scheme to ensure the position accuracy of a small-size cooling hole on the flame tube, but the method still stays on the process improvement level, does not relate to the optimal design of the cooling hole, and cannot solve the problem of uneven cooling performance of the flame tube. Patent CN108592086a discloses a combustion assembly of an engine, an integrated design and manufacturing method of the combustion assembly, and an engine, and the patent utilizes additive manufacturing technology to integrally design and manufacture the combustion assembly of the engine, and fuses a flame tube and a nozzle into a whole, so that the structure of the combustion assembly can be simplified, and the supporting and connecting structures among all components of the combustion assembly can be reduced, but the patent does not relate to the optimal design of cooling holes, and can not solve the problem of uneven cooling performance of the flame tube. Patent CN112484077a discloses a high-efficiency cooling structure of the head of the flame tube, but the patent relies on structural design improvement, and does not relate to the optimization design of cooling holes, and can not solve the problem of uneven cooling performance of the flame tube. Disclosure of Invention In view of the defects in the prior art, the invention provides a flame tube cooling hole design and manufacturing method based on temperature field constraint and additive manufacturing, which can realize accurate optimization of the layout of the flame tube cooling hole through thermal load distribution analysis of the surface of the flame tube and realize integrated manufacturing of the flame tube cooling hole through a laser powder bed melting additive manufacturing process. The technical scheme adopted for solving the technical problems is as follows: a flame tube cooling hole design and manufacturing method based on temperature field constraint and additive manufacturing comprises the following steps: s1, acquiring flame tube surface temperature distribution data through full-working-condition thermal simulation; S2.1, carrying out optimal design of cooling holes of the flame tube according to a temperature threshold and thermal gradient distribution based on the flame tube surface temperature distribution data obtained in the step S1, and generating a preliminary optimal cooling hole distribution scheme; s2.2, rei