Design Of Turbine Blade Thermal Eriosion Wind Tunnel And Experimental Study

Turbine blades are widely used in energy, metallurgy, petroleum, chemical and other industrial fields, the high temperature gas produced in industrial process can destroy the blade profile and lead to the decline of its aerodynamic performance, and shorten the service life of the equipment. To study the anti erosion characteristics of blade material under multiple conditions has a very practical significance to improve the efficiency of turbine energy conversion and ensure the safety operation of the turbine.The main means of studying materials anti erosion characteristics,are numerical simulation and experimental reaserch. At present, there are few experimental platforms,especially hot state erosion wind tunnel, but the working environment of turbine blade is high temperature flue gas. Existing experimental equipment has defects such as uneven gas mixing, air flow instability, the experimental temperature fluctuations and the difficult to accurately control. Therefore, it is important to design new erosion experimental platform to solve the above problems, and to simulate the real working conditions of turbine blades is important to the experimental study of blade erosion, and the erosion experimental data acquired by this platform is more convincing. This research mainly includes the following contents:(1) Designed and implementated of a high temperature, low Maher number(M<0.3),negative pressure wind tunnel test system for experimental study of turbine blade erosion,erosion behavior and law.The system use fan for providing negative pressure, electric heater for air flow variable temperature heating, finned tube heat exchanger to cool the two-phase flow, bag filter to recover erosion particle, DIGATTOT serial port server and PC to acquire experiment data and monitor system. The emphasis is on design of system frame,method of particle introduction, calculation of the optimum erosion distance, estimation method of the particle impact velocity, hardware and software design of data acquisition and control system. Syetem maximum temperature of the test system can reach 750, the particle concentration of the gas- solid two- phase flow can be adjusted, the erosion rate can be adjusted, and the adjustment of arbitrary angle from 90 to 0 degree. Temperature,speed stability and performance test of the system are also carried out. The results showthat the test bench has reached the design target.(2) On the experimental platform, studied the erosion characteristics of 1Cr12 Mo,solid phase concentration of gas and solid phase was 0.22~0.29%, particle velocity was75m/s, test temperature was 200 ℃, 300 ℃ and 400 ℃. The results showed that accumulated weight loss and accumulated erosion amount were linear, and the maximum erosion rate at different temperatures were both between 20-25 °, temperature 300 ℃erosion resistance of 1Cr12 Mo was better than 200℃ and 400℃.(3) This paper analyzed the causes and restrain methods of two experimental errors. a.for the cause of high temperature metal oxidation, introduced a kind of data correction method; b. For the erosion blind spot area low attack angle, according to the design scheme analyzed cause of the blind area and deduced the formula for calculating the area of the blind area and calculated the compensation factor.