【作者】 王新北；

【导师】 戴景民；

【作者基本信息】 哈尔滨工业大学 ， 仪器科学与技术， 2007， 博士

【摘要】 发射率是描述物体热辐射特性的重要参数,在航天、航空、国防、科学研究及工农业生产等领域中具有重要研究意义和应用价值。例如,当航天飞机、卫星在空间飞行时,它们表面的辐射特性数据是其热控制的重要依据。在红外制导武器对抗中,对导弹火焰和蒙皮辐射特性数据的掌握是能否突防的关键,而对军事目标辐射特性的认知又是能否有效攻击和隐身的重要因素。在民用领域中,在粮食、油漆、皮革烘干、电采暖中,加热体辐射特性的控制是节能降耗和提高生产效率的重要技术。在辐射测温技术中,发射率是现有测温方法中想得到目标真温而必须先知的唯一参数,也是影响目前辐射测温技术广范应用的瓶颈技术。材料发射率不仅取决于材料的组成成分和材料的表面状态(粗糙度、氧化等),还与材料的温度、考察的波长及观察的方向等因素有关。它不是物质的本征特性,随外界条件变化,不易测得。多年来,各国学者进行了大量和深入的研究,提出了很多测量方法,研制了种类繁多的测量设备,得到大量热物性数据。但是不得不承认:目前发射率的测量技术水平还不够高,数据分散性较大,而且我国还处于起步状态。因此,本文在国家自然科学基金和航天材料与工艺研究所的资金支持下,在建立基于傅里叶红外光谱仪的光谱发射率测量装置的基础上,对光谱发射率测量技术进行深入的研究。本文主要完成了以下几方面的创新性研究工作:1.研制基于傅里叶红外光谱仪的材料光谱发射率测量装置。设计了试样加热炉、参考黑体炉、反射式聚光光路、恒温环境腔体和真空系统。采用恒温环境辐射补偿技术,有效地消除背景辐射的影响。系统的主要技术指标优于国际同类装置。2.考虑到环境辐射对测量结果的影响,提出了背景辐射补偿新算法。测量环境的背景辐射包括两个部分:一是光谱仪内部辐射,另一个是光谱仪外部辐射,它们通过一定的方式耦合到光谱仪中去,给测量结果造成较大影响。本文提出了两次测量的环境补偿新算法,有效消除了环境的影响。3.从维恩位移定律得到启示,提出一种基于光谱测量温度的新方法。采用傅里叶红外光谱仪,测量目标的辐射光谱曲线,找到曲线峰值时的波长,再根据维恩位移定律得到目标的温度,称为光谱极值法。理论上分析了采用该方法测量黑体目标和实际目标的不确定度,建立了验证装置,并进行验证实验,理论和实验都证明了该方法具有较高的测量精度和实用性。4.利用本文研制的光谱发射率测量装置,对两种航天材料的光谱发射率进行了测量实验研究,揭示了材料光谱辐射特性随波长和温度的变化规律。对测量系统进行了不确定度分析,结果表明系统测量不确定度满足设计要求。系统研制后,受多个单位的委托,进行了多种材料的发射率测量试验,给委托单位提供了详细的测量数据,为委托单位的材料(型号)设计提供了基础数据,体现了该系统研制的必要性。更多还原

【Abstract】 The emissivity is an important parameter which describes the thermal radiative property of material, and it has a wide application in the aeronautics, astronautics, national defence, science research, industry, agriculture and other research fields. For example, the radiative characteristic of aerospace crafts and satellite is important for temperature controlling when they fly in the airspace. The radiative characteristic of missile plume and skin is a necessary parameter in the antagonism between the infrared guided weapon, and the radiative characteristic of military targets also has a critical effect on the attack and hiding of military targets. On the other hand, in the field of food supplies, oil paint, leather drying and electric heating, the control of the radiative characteristic of heating target is an important technique for the decrease on energy consumption and increase on production efficiency. In the radiative temperature measurement, the radiative is a necessary prior parameter before the true temperature is known, so the problem of the measurement of radiative is a bottle-neck in the radiative temperature research.The emissivity not only depends on the components of material and surface state (such as roughness, oxidation), but also on the temperature and wavelength measured. The emissivity is not a characteristic parameter of material itself, but it varies with the external condition. Lots of studies had done much research, and provided many useful methods, and developed all kinds of equipment as well. But the level of emissivity measurement is not satisfactory, the dispersity of data is larger, and we are at the initial step. The research comes from the project of National Natural Science Foundation of China and Aerospace Research Institute of Materials & Processing Technology. The purpose of this project is to research the spectrum emissivity according the measurement equipment based on Fourier transform spectrometer. The finished research works are as follows:1. A new measurement equipment has been researched based on the Fourier transform spectrometer. The stove for heating specimen, reference blackbody stove, light path with condenser mirror, cavity body at constant temperature and vacuum system have been designed. This system can work in spectral range from 0.6μm to 25μm and in the temperature range from 60℃to 1500℃, and the measurement precision can get to 3%.2. A new method for compensating the influence of surrounding radiation has been proposed. At the infrared spectral region, the stray radiation from surrounding may be comparable to target’s radiation, and the surrounding radiation contains the radiation inside the instrument and the radiation outside the instrument. The two kinds of radiation can come into the instrument by some couple mode, which will have a bad effect on the measurement results. So the new method for compensating the influence of surrounding radiation by twice measurement eliminates the influence of surrounding radiation effectively.3.A new method for temperature measurement has been proposed based on the Wien displacement law. First, the radiant spectral curve of target can be measured by a Fourier transform spectrometer, second, the peak value of curve can be found and corresponding wavelength must be marked. Third, the temperature of target can be calculated by Wien displacement law. We call this method as Peak Wavelength Method-PWM. For blackbody surface and real surface, theoretical and experimental analysis on the uncertainty is done, and a set-up is constructed and tested. They prove that PWM method has a high accuracy and practicability.4. A series of experiments have been done using the apparatus developed to measure the spectral eimssivity of materials. The results show that the data measured agree well with the data from literature. In the end, the uncertainty has been estimated for this apparatus and its result also proves this measurement system can satisfy the design demand.更多还原