REMOTE MONITORING SERVICES       Offered by:        TRK Engineering Services, Inc. & EPSCO International, Inc.

ESP Problems?

Read how advanced technology can be used to help eliminate unnecessary stress.

Weekends, holidays, the middle of the night, the need for support never occurs at convenient times, and everyone is aware by now, the Environmental Protection Agency (EPA) has promulgated the Compliance Assurance Monitoring (CAM) rule, placing greater demands on compliance issues and plant resources.  How can you find service support when you need it?  It is only a phone call away.  The engineering staff of  TRK Engineering Inc.  specializing in ESP start-up and operation including help with process condition. TRK Engineering’s Remote Monitoring Service can make your ESP modem connection a valuable component of your maintenance team.  By using a modem on your system, information can be used by TRK Engineering to reduce any problem situations to a minimum occurrence, as well as add credibility to Title V/CAM reporting. "Our objective is to make sure that the control device operator has the support required for the ESP control device, to the production process.  We want him to be ready for a compliance test every day."

Think about it, you can save on travel cost, maximize production, and use the reports as part of your semiannual reporting.  We can offer an array of services covering AVC and process troubleshooting to ESP computer performance modeling.  Need assistance with your CAM reporting? The electrostatic precipitator (ESP) performance model will provide a useful mechanism for evaluating the performance of ESPs under the CAM rule of your Title V permitting.

Regulations require that every source must have an operating permit. Permits must contain a Compliance Assurance Monitoring (CAM) plan that describes how the source will comply with applicable requirements.  Operating permits cannot be issued for more than 5 years.  Permits must require monitoring and the reporting of emissions, and incorporate emission limitations and other requirements of the applicable state implementation plans.

CAM Plan Development

• Single maximum or minimum values
• A series of maximum or minimum values that relate to various process conditions
• Designated operational conditions
• Absolute or percentage maximum or minimum deviations from a set value

• Provide justification for the elements in each proposed CAM plan
• Identify indicators to be monitored
• Establish acceptable values or ranges for these indicators
• Identify methods and frequency for collecting and averaging indicators
• Identify the monitoring approach that will demonstrate that control devices perform as  
  required, and that the indicators reside within the ranges identified
• Monitor any excursion from these indicator ranges
• Institute corrective action for these excursions
• Define performance criteria and QA activities
• Report excursions with information about duration and corrective actions

Use of ESP computer models for prediction of actual emission rates. These models must be calibrated for the installation to be effective in predicting a wide range of operating conditions.  Existing opacity monitors can be used as a trigger for the use of these models, as well as some other specific ESP operations parameters.

This CAM plan protocol is based on the use of ESP computer models, as described above.  As discussed above, the CAM plan will have to be customized for individual states and plants, but the basic protocol will be established.  The protocol will give the utilities some options that will have to be evaluated.  This protocol calls for the use of the existing opacity monitors as a trigger for the use of the model to indicate if current operating conditions are within compliance.  If the model indicates compliance, there is nothing more to be done.  If not, there are procedures to be followed, including derating until the causes of the excursion can be identified and remedied.  If the CAM plan requires monitoring of specific indicators, the maximums, minimums, ranges, and averaging times must be established.  This is part of the process of developing the CAM plan and should not be established during the bidding process.  Process data such as flue gas volume, temperature, and oxygen level are indicators that could be monitored.  This data is available from the CEMs or from the plant data acquisition system.  The CAM plan averaging times should match the existing averaging specification, where possible.  The key ESP operating indicators are the operating voltage, operating current, corona power, spark rate, and number of fields in service.


POSSIBLE CAM PROTOCOL APPROACHES FOR ESPs

A number of possible CAM Protocol approaches come to mind when relating particulate mass emissions to a "reasonable assurance of compliance." Included are:

• Direct Particulate Mass Monitoring
• Test and Cap
• Opacity/Mass Correlation
• ESP Power/Mass Correlation
• ESP Model Extrapolation
  

Direct particulate mass emissions monitoring would obviously be the choice if the technology was available.  Unfortunately, we do not believe this technology is ready for compliance determination purposes.  A number of different particulate mass monitors have recently been tested by the EPA.  The EPA used a new Performance Specification (PS-11) to evaluate the performance of particulate mass monitors.  Again, we do not believe this technology is ready for compliance determination purposes.

Test and Cap

The test and cap approach is very simple and straightforward and was the original particulate approach contemplated by the CAM rule.  This approach is to simply perform a compliance test and, if the control device (ESP) showed in compliance operation, then future operation would be limited to the opacity during the compliance test plus 2%. In other words, if compliance was demonstrated at 5% opacity, future operation would be capped at 7% opacity.  However, this approach would seriously compromise the ability of an ESP to use performance margin that had been purchased by the utility.

Opacity/mass and ESP Power/mass Correlations

Opacity/mass correlation and ESP power/mass correlation are other "compliance demonstration" techniques that have been used by utilities and states in the past.  Given a consistent supply of coal and some ESP performance margin, opacity/mass correlation might be a useful approach under certain circumstances.  ESP power/mass correlation does not appear to be a useful approach because the particulate collection rate in an ESP depends on the specific section of the ESP where the power is applied.  The permeations and combinations are just too complex for a simple correlation to handle adequately.

ESP Model Extrapolation

It is believed that the ESP model extrapolation has a high probability of being a useful CAM tool for ESPs.  Both the EPA and EPRI have developed ESP performance computer models over the past 15 years that calculate ESP performance on fundamental principles.  It has been shown many times that, when calibrated to a specific ESP, the models perform very well in predicting ESP performance changes from physical or electrical modifications to the ESP.  The ESP model also has the capability of accounting for power variations in the various ESP electrical sections and for sections that are out of service.  The model inherently compensates for fuel changes that influence the ash resistivity because these changes are reflected in the voltage and current relationships.  In addition, using an ESP model for CAM will allow the utilization of ESP performance margin, while other approaches are likely to restrict the use of margin.  Another advantage of using the model is that it can be used for planning purposes.  For example, one could examine the potential impact of a fuel change or evaluate the effect of additional ESP electrical sections being shorted.  It is important to understand that, even under the best of circumstances, an ESP model will not provide information sufficient for absolute compliance determination purposes.  It is believed, however; that the information will be more than adequate for CAM where the criteria is "a reasonable assurance of compliance."

The owner or operator must commence monitoring upon issuance of the permit or by the later date specified in the permit.  CAM equipment (including the necessary spare parts) must be maintained, repaired, and checked using the appropriate QA/QC at all times that the unit is operating.

For the purposes of CAM, an excursion is defined as a departure from an indicator range established for CAM, consistent with any averaging period specified for averaging the results of the monitoring.  An exceedance is defined as a condition that is detected by CAM that provides data in terms of an emission limitation or standard and that indicates that emissions (or opacity) are greater than (or less than, in the case of a percent reduction requirement) the applicable emission limitation or standard.

Upon detecting an excursion or exceedance, the owner or operator must restore the unit to its normal operation as expeditiously as practicable.  The response to an excursion or exceedance shall include minimizing the period of any startup, shutdown or malfunction and taking any necessary corrective actions to prevent likely recurrences.  The permitting authority will determine whether or not the owner or operator has used acceptable procedures in response to an excursion or exceedance based on the information available, "which may include but not be limited to, monitoring results, review of operation and maintenance procedures and records, and inspection of the control device, associated capture system, and the process.

If the owner or operator identifies a failure to achieve compliance with an emission limit or standard that was not identified by CAM as an excursion or exceedance, the permitting authority must be notified promptly and if necessary, proposed modifications to the permit, addressing CAM Plan revisions, must be submitted.

Following "commencement of operation" of an approved CAM approach, the owner or operator must submit CAM reports to the permitting authority at least once every six months (typically, it is once per month).  The reported information must include:

(1) The duration and cause of any excursion and the corrective action required to resolve the excursion.

(2) The duration and cause of each CAM downtime incident (other than downtime associated with daily calibration checks).

(3) A description of the actions taken to implement a Quality Improvement Plan, (QIP) during the reporting period.  Upon completion of a QIP, the owner or operator must include - in the next semiannual report - documentation that the plan has been implemented and has reduced the likelihood of similar levels of excursions or exceedances occurring.

The owner or operator must maintain records of all monitoring data, monitoring performance, corrective actions taken, QIP activities, and QA/QC activities.  Paper copies of the records do not have to be maintained; other media such as computer files can be used, provided that the records will be available for "expeditious inspection and review."

Monitoring Approach:

The key elements of the monitoring approach, including the indicators to be monitored, indicator ranges, and performance criteria to be presented are the opacity of the ESP exhaust and the results of an ESP computer model (the Electric Power Research Institute’s [EPRI] ESPM) that uses ESP operating parameters (voltage and current in each field) as its inputs.  The model is calibrated based on boiler, coal, flue gas, and fly ash characteristics, ESP inlet particle data, performance test data, operating data, and other ESP-specific "fitting factors" (velocity standard deviation, sneakage fraction, and rapping reentrainment fraction).

Example of ESP Performance Model calibration data needed

The output of the ESP performance model may be shown as a computer display or printout.  For purposes of this protocol, the output may be converted to and reported as an ESP control efficiency.  The ESP performance model output is compared with a pre-established indicator range (e.g., minimum acceptable control efficiency) that based on site-specific testing and ESP equipment evaluation provides a reasonable assurance of compliance with the applicable PM emissions limit. Findings of ESP performance model indicator values beyond the specified indicator range trigger corrective action and reporting obligations.

As the above information points out Remote Access technology can be a workable advantage to your troubleshooting and reporting needs.

Now that you have observed the requirements mandated by Title V, examine the proposed services offered.

Remote Access can provide:

              Dialup or internet access gives you and your engineering team on the spot analysis and assistances for troubleshooting questionable operations.

              Protocol establishes the format and chain of command required by the plants operation prior to making a dialup connection or possible system
              change.  All action taken will follow mandated written protocol.

              All information is handled confidentially. Reporting will follow established protocol.

              Monitored data can be formatted into report form, supplementing required data of selected indicator parameters showing compliance.

              This service can perform a collection of functions from CAM compliance reporting to indicators of performance when changing fuels,
              addition of fields and rapper changes. 

              Report format can be constructed to meet any reporting.

              Don’t think the standard subscription is exactly what your plant needs?. Give us an idea of what your needs are. Let us know what kind of
              service you require.

Use our experience to help you plan maintenance and outage work.

Power readings obtained organized by chambers

Analysis: (Analysis of the T/R set operational data only)

1. A10, B6, B9 & B14 appears to have secondary voltage metering problems.  Verification of the primary voltage would be the first step in analyzing the problem.  The primary voltage needs to be picked up in the proper location, between the CLR and the T/R set primary input. If this voltage pick-up location is incorrect, a short on the secondary side of the T/R set would indicate such data readings.   Measure the actual primary voltage using a true RMS meter. If the RMS meter agrees with the data, secondary voltage metering problems exist.   The secondary voltage and current return wiring and associated metering should be examined for reliability of the signal.  Check to see that the wiring is actually connected, examine the surge arrestors for a short or low resistance and verify that the feed back resistors, external and in the T/R tank, are the correct values.
   
2. Comparing the power levels of the A ESP verses the B ESP would indicate that the A ESP is operating at a higher resistivity level than the B ESP.  In a power plant this would typically be a result of a difference in gas temperature, SO3 injection rates or carbon carryover.  The B side may actually be operating poorer because of excessive reentrainment losses caused by a low ash resistivity.  The plant should check the SO3 injection rates and flue gas temperatures and experiment with changes to these levels to determine the affect on the ESP.  LOI samples should be taken to determine if the LOI levels are up on the A or B ESPs.
   
3. Comparing the power levels between chambers would indicate that the power levels are being effected by a temperature gradient created by the air preheater.  The A1- A12 side and the B1- B12 side are both in the higher resistivity range for there respective ESPs.  On the A ESP this is indicated by the higher spark rates in the A1-A12 side verses the lower spark rates in the A6-A14.  In the B ESP this is indicated by the higher average primary voltage levels in the B1-B12 side verses the lower average primary voltage levels in the B6-B14 with both sides operating at current limits.  Based on this information we would recommend more rapping on the higher resistivity sides and less on the lower resistivity sides to help optimize ESP operations.
   
4. Sparking in B2  may indicate an alignment problem or a close clearance.  The plant should also check the hopper area for ash buildup, check rappers for proper operation and check for localized in-leakage.
   
   More detailed analysis can be done if the process parameters and trending are available.

Standard Service:

Once a month dial in to examine your ESP's’ operations.  Review/analysis of the trended data for the last month and the actual operating conditions during each session.  This type of preventative maintenance program will help to insure that your equipment is operating efficiently. We have the experience to pinpoint problems with the controls, rappers and the process prior to them resulting in a failure or increase in opacity.

When a problem does develop we can assist you without making a costly trip to the plant and in many instances identify and possibly correct the problem more quickly to help reduce cost, emissions levels, and keep the ESP operating reliably.

Call TRK Engineering Services Inc. for a customized plan that meets your needs. .

(Normally, a monthly session will last 2 hours and it should take 2 hours to prepare a short report. Based on this schedule we feel that 4 hours is needed each month and we would like an additional 4 hours to be available on the contract each month to handle troubleshooting calls if needed).

** We feel a sound background in ESP fundamentals is essential to a good working relationship; therefore, the annual fee includes a  free admission for one to any of our Precipitator Seminars courses.

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Last updated: May 10, 2009.
Copyright © 1997 TRK Engineering Services, Inc. All rights reserved.
For more information contact: TRK Engineering Services - 95 Clarks Farm Road - Carlisle, MA 01741 - Telephone: 978-287-0550 - Fax: 978-287-0569 - email: trkeng@apcnetwork.com