Xi'an gas-line analysis system

Prepare the flue gas dust monitoring process cartridge 2 in priorities 1.2.1 before sampling is necessary tool for monitoring the work, put in the flue for catching dust, it requires careful preparation before sampling. Requirement for cartridge cylinder wall should be uniform, too thick, too thin or have a needle hole of the tube wall should be promptly abandoned. Because the tube wall thickness, during sampling resistance, smoke soot particles are not easily inhaled; tube wall is thin, low intensity, flue gas dust easily broken through the cylinder wall. Common glass fiber cartridge, while monitoring the process also must have a blank cartridge has been involved, for reference, correcting errors. Also before sampling for testing equipment to conduct a comprehensive detailed inspection, including sampling pumps, sensors and monitors. Check instrument piping system for leaks and clogging, if the problem should be solved in order to make the monitoring work carried out smoothly. 1.2.2 The choice of sampling location monitoring points should be selected in the pipeline gas flow smooth vertical and horizontal pipe section, to avoid abrupt changes in cross-sectional shape of the pipe and elbow, cut gas flow sampling section is not less than 5 m / s. Determine the number of sampling points and the sampling section of the shape, size and the airflow at the relevant section. Each section of the measuring points to be arranged in accordance with the specifications as much as possible, in order to ensure the accuracy of the measured data. For example, section away from the elbow and even parts of the airflow is relatively uniform, can take less number of monitoring points; and only when forced to bend or cross-section abrupt change from the vicinity of the site monitoring point selection, more disposed to try a number of monitoring points, which guarantees more accurate data. 1.2.3 Temperature and humidity control temperature and humidity in the flue gas dust monitoring process is to focus on the data obtained. Often used to measure the temperature of the sample at the point of a gun in the monitoring sampling, analysis of the data to the instrument. Dry and wet bulb humidity measurement commonly used method, gas flow rate after a certain psychrometer give temperature of the gas, according to the exhaust pressure monitoring point, we can calculate the amount of water in the flue gas dust, that humidity. 1.2.4 flow control and sampling in order to obtain more accurate data, isokinetic sampling method should be used. The so-called isokinetic sampling refers to the speed of the gas entering the sampling nozzle is equivalent to the gas velocity at the sampling point. Isokinetic sampling method is different, for various parts of the flue gas flow rates consistent with different sampling mouth, so that different flow rates of the flue gas flow into the sampling mouth, constant outflow of gas. When everything is ready to start monitoring. First, the monitoring instrument zero, weighed into the cartridge in the sampling tube, packed calculation sampling nozzle connected pipeline, when sampling hole in a closed state. When the gas flow has stabilized, and gradually into the sampling state, then open the sampling hole, followed by the sampling nozzle aligned with the direction of airflow, complete sampling. After sampling the sampling nozzle in the opposite direction to the gas flow direction, remove the sampling tube, weigh the quality of the filter cartridge inhaled soot particles, and re-test time, if the flue gas flow rate and the previous weighing results differ by more than ± 20%, the Samples void. After all the work done, check that the instrument is in good condition and clean. If the sampling process found the phenomenon of high oxygen content may appear in the boiler system is the large amount of leakage or the wind caused. Boiler equipment should be checked, in case of air leakage, sealing measures taken to deal with the flue system, the amount of the wind situation, they have to be transferred in the boiler system to match. 1.2.5 Data recording and process monitoring of preparation, to carefully record the model of boiler equipment manufacturer, the production capacity, temperature, humidity, barometric pressure and wind speed, flue diameter and height; the end of the monitoring work should timely data carefully recorded each monitoring point, and after the check, fill in the appropriate form. Fill in the form to strictly comply with national standards to ensure the integrity, accuracy and fairness of monitoring data. Two pairs of factors that may affect the flue gas dust monitor main factors to monitor the environment, the use of air flow and equipment and maintenance. Flue dust monitoring be under the specification of environmental conditions, in many cases, the position of the monitoring site, blower and valve incorrect, monitoring data will be distorted. Ambient temperature and humidity also affect the flow rate of flue dust, so that the actual monitoring data deviate from the real data. Wind effect size into the flue gas stream static pressure, dynamic pressure and flow rate, affecting isokinetic sampling nozzle selection calculations. The same equipment, the same environmental conditions in the different operating staff, monitoring data obtained is not the same. The useful life of the device, the size of the bearing capacity and the maintenance of conditions of monitoring data is great. For example, when the boiler load of 60%, dust emission concentration is 30% of the rated load; boiler load of 80% of the time, dust emission concentration is increased to 65%. Three pairs of boiler flue gas dust monitoring gives some recommendations a) boiler fuel to choose the type of complex national standard coal-fired boilers and other combustion equipment should be selected in line with the requirements of the environmental assessment model country, monitoring must be well prepared before the start , carefully check dedusting equipment performance is good, and the flue pipe is airtight and has a good variety of monitoring tools are in top working condition; b) monitoring departments should focus on improving the monitoring of the environment, such as the monitoring process the ambient temperature, humidity and pressure control; c) monitoring departments to strengthen the professional quality of the cogeneration sector and Professional Ethics staff. Boiler work professional level of personnel, their grasp of the amount of fuel used is reasonable and the wind amount of the excess air coefficient is close to the national standards, combustion of the fuel is relatively full, emissions of smoke dust concentration verges on national standards, Monitoring data obtained in the course also more accurate, while monitoring the workload will be greatly reduced. 4 Conclusion boiler flue gas dust emissions and concentration are key factors related to air quality, the basic content of its monitoring is monitoring China's environmental protection department. Monitoring boiler flue gas dust is not easy to implement, investigate the causes and to diversify its boiler models, as well as the complexity of the overall quality of workers in the field related to environmental conditions. But no matter how complex the situation, monitoring has a uniform national standards, that boiler soot GB13271-2011 monitoring methods. Staff should strictly abide by national standards, carefully carry out every one minute of work to ensure monitoring results completeness, accuracy and impartiality.