With the end of the year approaching, heavy pollution weather, supervision, and help check and air quality ranking have become the focus of online monitoring related personnel, in the face of the next half month may occur heavy pollution weather and extraordinary control requirements, sewage units and operation and maintenance units how to deal with heavy pollution weather online monitoring operation and maintenance, reduce operation and maintenance risks, improve the accuracy of monitoring data, has also become the online monitoring of the relevant personnel concerns and interests. It has also become an issue of concern and interest for online monitoring-related personnel.

CEMS Inspection Concerns

1. Emission plume & particulate matter concentration: For some occasions where the smoke at the emission port is trailing or there is a “big white dragon” in the emission, the authenticity and accuracy of the particulate matter concentration monitoring data will be questioned, and on-site inspections will generally be carried out to query the particulate matter concentration data, query the data of the particulate matter concentration monitoring equipment for a long period. Scope and data changes, data correlation with the operation of production and management facilities, daily calibration operations and manual comparison monitoring of particulate matter concentration data, on-site inspection of the particulate matter concentration monitoring equipment measurement methods, principles of operation, sampling conditions and the relevant parameters set in the equipment, especially focusing on checking the installation of sampling pipelines, sampling nozzles, and testing the relevant performance indicators of the equipment. The contents of the inspection and common problems of the extractive particulate matter concentration monitoring equipment are as follows:

• Whether the sampling is isochronous tracking is used, and whether the sampling isochronous tracking error meets the requirements of the technical specifications (not more than ±8%);
• Test isochronous tracking response, adjust the measured flue gas flow rate to observe the changes in the sampling flow rate, as well as the response time of the sampling flow rate tracking (isochronous tracking response time should not exceed 20s);
• Sampling line airtightness, i.e. whether there is any leakage or dilution of sample gas from the sampling probe to the negative pressure area at the front of the jet pump;
• Attachment, adsorption, and loss of particulate matter within the sampling pipeline and detection unit, and the presence of large accumulations of particulate matter within the pipeline, which can create uncertainty in the monitoring data;
• Sampling pipeline and detection unit heating, high humidity and high temperature occasions pipeline and detection unit is not heated or heating temperature is insufficient, it is easy to form liquid water, the concentration of particles and sampling and measurement of the formation of impact;
• The direction of installation of sampling nozzles in the flue or chimney and the size of the sampling nozzles, no sampling nozzles or the direction of the sampling nozzles is not correct to the air flow of the data to form an uncertainty, need to cause concern;
• Corrosion of sampling probes and the presence of unidentified holes in the probes or tubing that create dilution of the sample taken or interfere with the sampling;
• Disturbance and dilution of the sampling by the measurement exhaust, for the equipment where the exhaust is returned to the chimney or flue after measurement, the return exhaust is upstream of the sampling nozzle and close to the position of the sampling nozzle, and the airflow at the sampling nozzle is disturbed or diluted, which creates an uncertainty effect on the sampling and measurement data.
• The length of the sampling probe is less than 20% of the diameter of the flue or chimney, and the straight pipe section does not meet the requirements of the technical specifications, the flow rate of the manually measured section varies greatly, the representativeness of the sampling is easily questioned, and the authenticity of the monitoring data should be paid attention to;
• Particulate matter CEMS measurement data is small, and manual monitoring data and CEMS data error is small, manual monitoring sampling standardization is easy to check the attention, the inspection needs to provide particulate matter comparison sampling video images and original data records, etc..

2. Hot and wet CEMS / emissions & humidity monitoring data: humidity as a flue gas parameter monitoring, in addition to reacting to changes in process conditions, in the hot and wet CEMS gaseous pollutant concentration and standard dry flow directly involved in the relevant calculations, which directly affects the concentration and emissions of the size of the need to focus on whether the humidity monitoring equipment is normal. Humidity monitoring equipment inspection content and common problems are as follows:

• Humidity monitoring data is at a constant value for a long period of time, or the monitoring data fluctuates in a small range around a certain monitoring value, and there is no significant change in the data during the start and stop of production;
• Extractable humidity measuring device, humidity data does not conform to the logic of the process conditions, and humidity monitoring equipment without the relevant display, there is the use of hand manipulator for operation;
• In-situ type measurement of humidity, where the temperature of the site conditions exceeds the applicable temperature range of the monitoring method for an extended period of time, and where the monitoring data are abnormal or where the monitoring data remain normal;
• In-situ humidity measurement device, after the shutdown of the data has been reduced, but the monitoring data in more than 5% or has been zero value, should be concerned about the humidity meter flue gas contact device clogging situation or sensor corrosion, damage to the situation;
• Humidity meter with advanced privileges password settings related parameters directly affect the humidity data, historical data found in some periods of time humidity data jumps and does not meet the process logic;
• Found that the humidity measurement data is abnormal or illogical, on-site through the air or nitrogen test, the data has no obvious change or data elevated;
• Failure of on-site humidity meters that are not replaced or repaired in a timely manner, and where the monitored humidity data deviates significantly from the manual monitoring data;
• Manual comparison of humidity data anomalies is found, and the monitoring data exceeds the error required by the technical specifications;
• Where humidity monitoring data is highly consistent with trends in data for monitoring factors such as temperature or oxygen, the source of the humidity display recording data signal should be of concern;
• On-site video images, records and operation logs reflecting in situ operation of the humidity meter or connecting to a computer or hand manipulator for operation, and where the humidity data changes significantly before and after the operation, and where no reasonable explanation can be given;

How to Conduct Year-End O&M?

In the face of a number of controls and requirements for year-end heavy polluted weather emergency, supervision and assistance inspections as well as air quality ranking assessment, emission units and operation and maintenance units should formulate online monitoring operation and maintenance contingency plans, and implement and execute them in strict accordance with the requirements of the plans. The online monitoring operation and maintenance contingency plan should include the abnormal response to online monitoring data exceeding the standard, the handling measures after the failure of online monitoring equipment, and the measures to cooperate with the law enforcement inspection of online monitoring at .

1. Online monitoring data exceeds the standard abnormal response processing timely and accurate. Year-end heavy pollution during the weather industrial enterprises tend to take corresponding emission reduction measures, and emission reduction in the reduction of conventional pollutant emissions, emissions need to be reduced from the emission concentration and exhaust gas emission flow in two aspects. Emission flow can not be reduced on the occasion, the sewage unit can only think of ways to reduce the concentration of pollutants from the pollutant emissions, pollutant concentration reduction accompanied by an increase in the amount of desulfurization and denitrification agent dosage, while a long period of time overloaded operation of the treatment facilities, slurry, water vapor and ammonia fugitive amount of doubled to the normal operation of the online monitoring equipment has had a serious impact on the monitoring data exceeded the abnormalities of the situation is also more and more frequent. In the face of online monitoring data exceeding standards and abnormalities, online monitoring operation and maintenance should do the following aspects of work.

• Timely detection of exceedance and abnormal data in online monitoring operation. Discharge units and operation and maintenance companies should establish a 24h monitoring system for online monitoring data, real-time calculations through the minute data to predict whether the hourly data exceeds the standard or the emissions exceed the control requirements, hourly data exceeds the standard or anomalies, should be found within 1h exceeding the standard and abnormal data, and relevant exceeding the standard and abnormal data should be recorded and notified.
• Exceeding abnormal data in time for verification and disposal. Online monitoring operation and maintenance or sewage units should be on-site within 2h to verify the online monitoring equipment work operation, verify the production of governance facilities operation and adjustment, the formation of online monitoring of abnormal data exceeding the standard work ledger, sewage units and operation and maintenance units to jointly record the confirmation of the reasons for exceeding the abnormal data. The operation and maintenance company can arrange operation and maintenance personnel to be stationed at the key emission enterprises or arrange operation and maintenance personnel to be on duty at night if conditions permit, so as to facilitate on-site verification and disposal of abnormal data exceeding the standard.
• Strengthen precautionary operation and maintenance and precise control of treatment facilities. Emission units should strengthen the level of precision control of treatment facilities during the emergency period of heavy polluted weather, to prevent and control the emergence of data about to exceed the standard, a large number of input desulfurization and denitrification agent, the formation of on-line monitoring sampling link blockage failure; operation and maintenance personnel should be encrypted during the emergency period of the on-line monitoring equipment sampling link blowback, clean up the frequency of the sampling preprocessing link shorten the replacement cycle of the consumables, to prevent and control the failure of consumables resulting in data anomalies or Exceed the standard.

2. Failures of online monitoring equipment should be detected in a timely manner, investigated accurately and handled efficiently. The sewage unit or operation and maintenance company should establish and improve the online monitoring equipment operating status and key parameters record or upload function, supplement to increase the online monitoring of commonly used spare parts and consumables reserves, strengthen the common troubleshooting and treatment of training and sharing, the formation of sewage units and operation and maintenance unit operation and maintenance personnel and management personnel 24h on duty in the post of the emergency mechanism. For online monitoring equipment failure emergency measures, operation and maintenance units and sewage units should do the following measures.

• Supplement and improve the number of spare parts, and form a full set of online monitoring equipment standby mechanism. Sewage units and operation and maintenance units of online monitoring spare parts inventory, expedited reserves of some commonly used consumables and spare parts, the establishment of a perfect spare parts and consumables supply system, and spare parts suppliers to communicate with the business, inventory and payment matters, to ensure that the urgent need for spare parts can be transported to the scene in the shortest possible time. The performance test of the spare machine is carried out to ensure that the spare machine can be replaced in time after the failure of the online monitoring equipment for operation and maintenance and that it works normally.
• Strengthen the analysis and judgment of online monitoring operation data and parameters, and form an early warning mechanism for online monitoring equipment failure. Sewage disposal units and operation and maintenance units should be based on the daily operation and maintenance frequency, combined with process conditions and equipment method principle, the daily maintenance of prejudgement; according to the daily calibration data drift situation on the aging of the equipment to judge the drift of serious and long running time of the equipment, timely maintenance of the equipment or enable the standby, prevention and control of heavy pollution emergency during the unstable equipment is not easy to verify and check the exceedance of the abnormal data.
• Formation of online monitoring operation and maintenance technical support system, operation and maintenance of technical personnel and manufacturers 24h on-site operation technical support. Operation and maintenance units within the formation of operation and maintenance supervisor 24h standby system, on-site operation and maintenance problems arising from remote guidance or on-site support, the occurrence of failures in operation and maintenance personnel failed to deal with, operation and maintenance supervisor or the person in charge of technology to deal with the scene in a timely manner; and equipment manufacturers to communicate with the requirements to provide 24h after-sales customer service telephone, for the scene of the equipment failure to provide technical support for the timely investigation and analysis.

3. Online monitoring of environmental protection checks in a timely manner on-site cooperation, truthful answers to inquiries and records of the inspection process. Sewage disposal units and online monitoring operation and maintenance units in the face of environmental protection departments at all levels of inspection, should verify the relevant documents of the law enforcement and inspection personnel, and proactively cooperate with the relevant operations, and truthfully answer the content of the inspection-related inquiries, the relevant inspection content truthfully recorded in the field ledger, the inspection of the relevant video and operation operation of the operation to stay in the evidence for the inspection of inspection should be concerned about the following aspects.