Method for calculating allowable difference of sampling inspection result of stored coal sample

Abstract

The invention discloses a method for calculating the allowable difference of sampling inspection results of stored and checked coal samples. The method comprises the following steps: preparing coal samples or mine coal samples into at least 10 pairs of samples with the same nominal maximum granularity and mass as the stored and checked samples, and numbering; preparing a pair of samples into analysis samples, testing the analysis samples to obtain the dry basis high calorific value, bottling the rest of the plurality of pairs of samples, placing the samples into a sample storage and check cabinet, preparing a pair of samples into analysis samples every several days, and testing the analysis samples to obtain the dry basis high calorific value of the ith pair of samples; establishing a regression equation of the dry basis high calorific value difference value and the storage time t; calculating a dry basis high calorific value difference value caused by the storage period; and calculating the allowable difference between the stored and checked coal sample with the nominal maximum granularity and the corresponding analysis sample, the allowable difference of the sampling inspection result of the stored and checked coal sample in the storage time period and the target value of the allowable difference between the stored and checked coal samples with different nominal maximum granularities and the corresponding analysis samples. The method disclosed by the invention is simple and convenient, and truthfully and accurately reflects the sampling inspection result difference value of the stored and checked coal sample and the stored sample management level.

Description

technical field [0001] The invention belongs to the technical field of coal combustion in thermal power plants, and in particular relates to a method for calculating the allowable difference of the random inspection results of stored coal samples. Background technique [0002] In the process management of coal-fired mining and production in thermal power plants, when there is doubt about the analysis results of raw coal samples or as a technical supervision and sampling inspection of coal-fired indicators, when the original coal samples are prepared in the sample preparation process, the same procedure and a certain In the sample preparation stage, samples are taken as coal samples for deposit and inspection. However, the current standard does not clearly stipulate the allowable difference in the sampling results of the stored coal samples. At present, most power plants use the reproducibility critical difference of calorific value measurement (dry basis high calorific valu...

AI Technical Summary

Problems solved by technology

For some high volatile or easily oxidized coals, calorific value loss will inevitably occur during storage, resulting in a large difference between the sampling results and the original analysis results.

Furthermore, the nominal maximum particle size of coal samples stored in most power plants is 3mm, while the nominal maximum particle size of coal samples stored in some power plants is selected as 6mm or 13mm. There is a reduction error in the sample preparation stage, which can easily cause a relatively large difference between the sampling results and the original analysis results

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