Convective losses of thermal infrared emitters with cantilevered heating elements
Convective losses of thermal infrared emitters with cantilevered heating elements
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带有悬臂式加热元件的热红外发射器的对流损失
DOI：
10.1016/j.sna.2018.06.039
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
G. Gerlach
中科院分区：
文献类型：
--
作者：
T. Ott;M. Schossig;G. Gerlach
非色散红外 (NDIR-) 气体传感器通常由热红外发射器、管和带有滤光片的热释电探测器组成，该滤光片对待检测气体的特征波长是透明的。由于热释电传感器仅对交变辐射敏感，因此必须对辐射进行调制。这最容易通过发射器的电调制来实现。在这种循环激励下，红外源的热力学特性会影响发射的红外辐射，从而影响传感器信号。最佳气体传感器操作（例如，关于气体测量分辨率）需要知道哪些因素影响热发射器的热力学特性。在小型化和便携式使用的过程中，气体测量设备也必须变得更加紧凑和节能。因此，辐射源必须具有低功耗和高（辐射）效率。在电（方波）调制过程中测量的加热和冷却曲线包含有关实际发射器热损失的所有信息，因此也包含有关其能源效率的所有信息。在本文中，将介绍红外发射器的热力学模型，其中还包括所有热损失（填充气体中的辐射、热传导和对流）。通过比较测量和计算的加热和冷却曲线，可以量化发射器的热损失并得出有关其能源效率的结论。因此，本文揭示了所提供的大部分电能通过对流和热传导耗散到填充气体中，这显着降低了辐射源的能量效率。真空测量证实了这一假设并支持该模型。
Non-dispersive infrared- (NDIR-) gas sensors usually consist of a thermal infrared emitter, a tube and a pyroelectric detector with a filter that is transparent to the characteristic wavelength of the gas to be detected. Since pyroelectric sensors are only sensitive to alternating radiation, the radiation must be modulated. This is easiest to achieve by electrical modulation of the emitter. Under this cyclic excitation the thermodynamic properties of the IR source affect the emitted infrared radiation and, in consequence, the sensor signal. Optimal gas sensor operations (e.g. with regard to gas measurement resolution) require to know which factors influence the thermodynamic properties of thermal emitters. In the course of miniaturization and with regard to portable use, gas measuring devices must also become more compact and energy-efficient. Consequently, the radiation source must have low power consumption and high (radiation) efficiency. The heating and cooling curves measured during electrical (square-wave) modulation contain all information about the thermal losses of real emitters and, therefore, about their energy efficiency as well. In this paper, a thermodynamic model of an infrared emitter will be introduced, which also includes all thermal losses (radiation, heat conduction and convection in the filling gas). The comparison of the measured and calculated heating and cooling curves allows to quantify the thermal losses of the emitter and to draw conclusions about its energy efficiency. As a result, this paper reveals that the majority of the electrical energy supplied is dissipated into the filling gas by convection and heat conduction, which significantly reduces the energy efficiency of the radiation source. Vacuum measurements confirm this assumption and support the model.
微型传感器系统的高温稳定微型仪器
DOI：
--
发表时间：
2009
期刊：
影响因子：
--
作者：
Jan Spannhake
通讯作者：
Jan Spannhake