Abstract

Three portable dilution devices (a two-stage dilutor, a one-stage dilutor and an axial dilutor) and a stationary dilution tunnel were compared by employing them in an experimental setup for particle emission measurements from a 40 kW pellet boiler. Total concentrations and number size distributions of particles were detected by an ELPI + analyzer. Averaged values of total particle emission per MJ received from measurements with available dilution devices were within the range between 3.14 × 10¹³ and 1.15 × 10¹⁴ for the full power regime, and between 1.54 × 10¹³ and 5.03 × 10¹³ for the reduced power regime. Measured particle concentrations decreased by using dilution devices in the following order: a two-stage dilutor, a one-stage dilutor, a dilution tunnel and an axial dilutor. The number size distributions of particles for the majority of cases are qualitatively similar for all devices for similar combustion regimes of the boiler. Applying dilution air with or without heating did not significantly affect the results of measurements. During multiple series of measurements the degree of dilution was varied when possible for different devices within a range between 8 and 102. No dependence of particle concentrations on the degree of dilution could be determined from these experiments. Applying a method of one-way analysis of variance revealed the statistically significant difference in particle concentrations measured with different dilution devices. Implementing this method to CO, and CO₂ gas emission components of different series it was determined that the boiler operation was stable as the measured data belong to the same distribution. Thus, the statistical differences in particle concentrations most likely relate to the varied measuring equipment, i.e., dilution devices.

Copyright © 2021 American Association for Aerosol Research

摘要

通过将三个便携式稀释装置（两级稀释器，一级稀释器和轴向稀释器）和固定式稀释通道进行比较，将它们用于实验设备中，以测量40 kW颗粒锅炉的颗粒排放。用ELPI +分析仪检测颗粒的总浓度和数量尺寸分布。对于全功率范围，使用可用的稀释装置进行测量得到的每MJ总粒子发射的平均值在3.14×10 ¹³和1.15×10 ¹⁴之间，并且在1.54×10 ¹³和5.03×10 ^13之间对于减少的权力制度。使用稀释装置按以下顺序降低了测得的颗粒浓度：两级稀释器，一级稀释器，稀释通道和轴向稀释器。在大多数情况下，对于锅炉相似燃烧状态下的所有设备，颗粒的数量分布在质量上都是相似的。在有或没有加热的情况下使用稀释空气不会显着影响测量结果。在多个系列的测量过程中，如果可能的话，对于不同的设备，稀释度会在8到102之间的范围内变化。从这些实验中无法确定颗粒浓度对稀释度的依赖性。应用方差的单向分析方法显示，使用不同的稀释设备测得的颗粒浓度具有统计学上的显着差异。对CO和CO实施此方法由于测量数据属于同一分布，因此确定了_2个不同系列的气体排放组件，确定了锅炉运行是稳定的。因此，颗粒浓度的统计差异很可能与变化的测量设备（即稀释设备）有关。

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