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CN-121994980-A - Multichannel sampling trapping and grading tar removal cooperative method for biomass gasification poly-generation device

CN121994980ACN 121994980 ACN121994980 ACN 121994980ACN-121994980-A

Abstract

The invention discloses a multi-channel sampling trapping and grading tar removal cooperative method for a biomass gasification poly-generation device, which relates to the technical field of biomass gas sampling analysis and purification control and comprises the steps of establishing a heating sampling pipeline with temperature control and a multi-channel sampling manifold, and constantly distributing flow of an analysis channel, a trapping channel and a safety channel; the main gas path sequentially passes through high-temperature filtration and multi-stage condensation, condensate is collected in separate bins, a sampling channel is used for collecting tar through a parallel adsorption tube/sampling bottle and periodically switched by a multi-way valve, sample gas is synchronously sent into a micro GC to obtain H2/CO/CH4/CO2 and other components, a standard gas is utilized for calibrating a sensor on line and constructing a soft measurement result of heat value and tar index, and when the tar index, pressure difference or CO leakage reaches a threshold value, the gas supply proportion of a condensing medium, a bypass catalytic cracking bed and a reactor is adjusted in a linkage mode, and inerting release and isolation are triggered. The method realizes the integration and coordination of sampling representativeness and tar removal, reduces the risk of dewing blockage and improves the safe and stable operation capacity of the distributed system.

Inventors

  • LI YUANXI
  • LIN WEICHENG
  • WANG XUYANG
  • LI XIN
  • CHEN YUTENG
  • HUANG TIANLANG
  • CHENG XIAOXUAN
  • ZHAO YUREN
  • SUN PEIXIN
  • Yue Ziao
  • ZHU YUANQING
  • ZHOU SANWEI
  • LI SHUQUAN
  • HOU HAORAN
  • LI LING

Assignees

  • 李垣希

Dates

Publication Date
20260508
Application Date
20260301

Claims (10)

  1. 1. A multi-channel sampling trapping and grading tar removal cooperative method for a biomass gasification poly-generation device is characterized by comprising the following steps: A heating sampling pipeline and a multi-channel sampling manifold which are communicated with the gasification outlet are established, and the flow of each channel is constantly distributed; performing fractional condensation on the main gas path through a condensation impurity removal and tar control unit and collecting condensate in separate bins; carrying out parallel adsorption trapping on tar and light hydrocarbon in a sampling channel through a multichannel sampling/trapping unit, and sending the sample gas of the other channel into a micro gas chromatograph for component analysis; Periodically calibrating the on-line sensor based on the micro gas chromatography analysis result to obtain a soft measurement result of the heat value and tar index; when tar index or pressure difference exceeds a threshold value, the flow rate of a condensing medium, the temperature of a bypass catalytic cracking bed and the ratio of gasifying agents in the reactor are regulated in a linkage way, and sampling and a main gas path are cut off to realize inerting discharge when safety thresholds such as tempering, CO leakage and the like are triggered.
  2. 2. The method according to claim 1, wherein the heating of the sampling pipeline is performed by controlling the pipeline temperature to 20-40 ℃ above the dew point of the sample gas through a heat tracing belt and a temperature sensor, and a high temperature resistant filter is arranged at the sampling inlet to reduce the content of the particulate matter with the particle size of >5 μm to a preset threshold.
  3. 3. The method of claim 1, wherein the constant distribution comprises providing a critical orifice plate or mass flow controller in each channel, controlling the flow ratio of the analysis channel, the capture channel and the safety channel to (0.2-0.5): (0.3-0.6): (0.1-0.3) in combination with manifold pressure feedback, and maintaining the total sampling flow to 1-5L/min.
  4. 4. The method of claim 1, wherein the parallel adsorption trapping comprises setting at least two adsorption tube groups as A/B trapping branches, switching through a multi-way valve according to a preset period t=5-30 min, enabling one branch to trap online while the other branch is subjected to desorption regeneration or replacement, and performing timestamp recording on switching time to form a tar trapping data set.
  5. 5. The method according to claim 1, wherein the fractional condensation comprises at least three stages of condensation sections, the condensation temperature windows of which are t1=120-220° C, T < 2> =30-90 ° C, T < 3 > = -5-15 ℃, respectively, and the dynamic correction is performed on T1, T2, T3 according to the gas flow and the tar index obtained by soft measurement, so that the residual amount of the tar at the outlet of the condensation sections is lower than a preset threshold.
  6. 6. The method of claim 1, wherein the periodic calibration comprises injecting standard gas mixture or zero gas into the sampling manifold every 1-6 h, and updating the zero point, the measuring range and the cross interference coefficient of the on-line sensor by using a weighted least square method by using components obtained by micro gas chromatography as a reference.
  7. 7. The method of claim 1 or 5, wherein the tar index is obtained by comprehensively calculating a condensate mass flow rate, an adsorption tube weight gain and a sample gas temperature-pressure-flow parameter by the formula TI=w1.m_cond+w2.m_ads+w3.DELTA.P_filter, wherein w1, w2, w3 are preset weights.
  8. 8. The method of claim 7, wherein when TI exceeds a threshold ti_h, at least one of the following controls is performed: Increasing the bed temperature of the reaction unit by 10-50 ℃ or reducing the feeding rate by 5-20% to prolong the residence time; the flow of the first-stage condensing section cooling medium is increased by 10-40%; And opening a catalytic cracking bypass and controlling the temperature of a cracking bed to be 650-850 ℃.
  9. 9. The method of claim 1, wherein the safety thresholds include at least sampling line differential pressure ΔP_samp≥3 kPa, main gas path differential pressure ΔP_main≥5 kPa, gas line CO leakage concentration≥50 ppm, outlet oxygen content≥2.0% or flashback signal detected, closing the sampling valve and performing an inerting gas purge on the sampling line and main gas path and switching the gas to a safety burner or flare when either safety threshold is met.
  10. 10. The method of claim 1, further comprising correlating micro gas chromatography, sensors, pressure differentials, and condensate staging yield data in batches to generate traceable operational data packets for plant operation and carbon accounting.

Description

Multichannel sampling trapping and grading tar removal cooperative method for biomass gasification poly-generation device Technical Field The invention relates to the technical field of biomass gas sampling analysis, purification and operation safety control, and particularly provides a multi-channel sampling trapping and grading tar removal cooperative method for a biomass gasification poly-generation device. Background Biomass gasification has good recycling value in heat supply, drying and distributed energy scenes, but gasified fuel gas generally contains dust, water vapor and tar. The condensation of tar at the cold end can cause the blockage of sampling pipelines and purifying equipment, resulting in monitoring distortion, equipment shutdown and safety risks. Meanwhile, accurate on-line analysis of the gas components/heat values often depends on expensive analysis instruments, and the rural end is difficult to maintain and high in cost. In the prior art, the sampling analysis and the tar removal purification are respectively designed as two independent systems, wherein the sampling system is easy to lose efficacy due to dew condensation, the purification system lacks a dynamic regulation strategy based on the real tar level, and the purification effect and the energy consumption are difficult to be simultaneously achieved. Therefore, a method for combining multi-channel representative sampling, tar grading trapping and online calibration control is urgently needed to realize long-term stable and safe operation. Disclosure of Invention In order to overcome the defects in the prior art, the embodiment of the invention provides a multi-channel sampling trapping and grading tar removal cooperative method for a biomass gasification poly-generation device, and sampling representativeness and purification control form a closed loop through the flow of heating sampling, constant current distribution, parallel trapping, grading condensation, on-line calibration, linkage control and safety interlocking. The technical scheme includes that a heating sampling pipeline and a multi-channel sampling manifold which are communicated with a gasification outlet are established, flow rates of all channels are constantly distributed, a condensation impurity removal and tar control unit is used for performing fractional condensation on a main gas path and collecting condensate in a separated bin, parallel adsorption and trapping are performed on tar and light hydrocarbons in a sampling channel through a multi-channel sampling/trapping unit, another channel sample gas is sent to a micro gas chromatograph for component analysis, a periodic calibration is performed on an online sensor based on the analysis result of the micro gas chromatograph to obtain a soft measurement result of heat value and tar index, when the tar index or the pressure difference exceeds a threshold value, the flow rate of a condensing medium, the temperature of a bypass catalytic cracking bed and the ratio of a reactor gasifying agent are adjusted in a linkage mode, and when a safety threshold value such as tempering, CO leakage and the like is triggered, the sampling and the main gas path are cut off to realize inerting discharge. In a preferred embodiment, the heating sampling pipeline controls the pipeline temperature to be 20-40 ℃ above the dew point of the sample gas through a heat tracing belt and a temperature sensor, and a high temperature resistant filter is arranged at a sampling inlet so as to reduce pollution of particulate matters to a downstream valve and an analyzer. In a preferred embodiment, the constant distribution is achieved by combining a critical orifice plate or a mass flow controller with manifold pressure feedback, and the flow ratio of the analysis channel, the capture channel and the safety channel is controlled to be (0.2-0.5): (0.3-0.6): (0.1-0.3). In a preferred embodiment, the parallel adsorption trapping periodically switches the A/B trapping branches through a multi-way valve, so that on-line trapping and desorption regeneration are alternately performed, and a tar trapping data set is formed by recording a time stamp. In a preferred embodiment, the fractional condensation is provided with at least three condensation sections, the condensation temperature windows are respectively t1=120-220° C, T2 =30-90° C, T3= -5-15 ℃, and the temperature or the flow rate of the cooling medium in each condensation section is dynamically corrected according to the tar index. In a preferred embodiment, the standard mixed gas or zero gas is injected every 1-6 h in the periodic calibration, and the calibration coefficient of the on-line sensor is updated by adopting a weighted least square method based on the micro gas chromatography analysis result, so that the error caused by drift and cross interference is reduced. The technical scheme provided by the invention has the following beneficial effects: (1) The sampling and tar removal puri