Development Of Heat Transfer Platform Base On The Third Boundary Condition

The temperature can reflect the degree of hot and cold of a substance,behind the changing temperature data it reflects the rule of heat conduction.We can understand the heat transfer process between a substance and environment or other medium by analyzing temperature data deeply.The heat transfer coefficient is an important parameter in the heat transfer process.It represents the heat exchange ability between the substance and the fluid.So it has great practical significance to obtain the heat transfer coefficient accurately in practical application.However,in some special environment,it is unable to acquire heat transfer coefficient by direct contact measurement.In this case,it usually use infrared thermal imager to measure temperature changing data of the target in non-contact way,and use the inverse heat conduction problem solving algorithm to calculate the convective heat transfer coefficient based on one or more points temperature data on the internal or boundary of the target.This kind of inverse problems which is related to heat transfer is called inverse heat conduction problem.At present,the research of inverse heat conduction problem is very active,but the research progress is mainly concentrated in the algorithm simulation stage.The literature about inversion calculation based on measured temperature changing data is very rare.Therefore we develop a heat transfer generation platform which is based on the existing several typical heat conduction models and the inverse heat conduction problem solving algorithm.The platform is built with third heat transfer boundary condition,and can produce the data which the inversion heat transfer problem required.In the meanwhile,the platform can offer the true value of the heat transfer coefficient to evaluate the results of the algorithm.In this dissertation,we investigate the research status of the heat transfer inversion analysis related theories and heat transfer inversion problem solving algorithm,and build the platform based on the one-dimensional unsteady heat conduction model combining the related technical criteria.After that we use QPSO optimization algorithm to estimate the heat transfer coefficient based on measured heat transfer data.In the design and construction of the experimental platform,we design the mechanical structure of the platform firstly,and then we select the type and parameters of the measurement sensor according to the inversion algorithm and related technical indicators.At last we formulate the communication protocol and control mode according to the connection between measuring models.In the programing and debugging of the software,we develop the data acquisition software based on each measuring models first of all,it realize the data display and storage functions.At the same time,the heat transfer inversion program is compiled based on QPSO optimization algorithm,and the wavelet denoising algorithm is added in aimed at the noise in actual measurement.According to the simulation results,the wavelet denoising enhances the noise immunity of the inversion algorithm.The maximum relative error of the inversion results is about 5% in the case of adding + 1% random noise.In view of the hardware design and software design in this dissertation,304 stainless steel was selected as the measured sample to multiple test,and acquire several sets of effective measured data.