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Production Process Insights

The Smart Approach to Cycle Chemistry

Posted by John Powalisz on 9/23/19 8:03 AM
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Cycle chemistry management is the best way to help prevent, recognize and minimize potentially devastating water chemistry events. Smart alarms assist in this by monitoring cycle chemistry, identifying chemistry events in real time and allowing chemists to take proper actions to correct conditions - preventing system damage and protecting assets.

Importance of cycle chemistry monitoring

In power plant operations, many things can affect cycle chemistry. From temperature to pressure changes, outputs vary and can affect analyzer performance. That’s why power plants use automated systems to control temperature, pressure and sample flow over a wide range of operating conditions to prevent corrosion and deposits on key equipment. 

Cycle chemistry monitoring systems help power plants maintain steam and water chemistry within operating limits. The most vulnerable systems to a water chemistry event are the equipment directly involved with condensate, feed water and other aspects of the steam/water cycle, such as boilers, turbines and heating systems.

Cycle chemistry monitoring systems help prevent corrosion and deposits by measuring:

  • Conductivity
  • Conductivity after cation exchange (CACE)
  • Degassed-CACE
  • pH
  • Oxidation-reduction or redox potential
  • Dissolved oxygen and sodium
  • Total organic carbon (TOC)
  • Silica
  • Phosphate

CYCLE CHEMISTRY Smart alarms & AI 

Diagnosing cycle chemistry events can be complicated using traditional analyzer alarm systems. Alarms might be present for non-critical reasons or due to individual analyzer issues, such as calibration, damaged sensors or depleted electrolytes.

Human factors also complicate the process of monitoring, identifying and correcting out-of-specification cycle chemistry. With all the potential for nuisance alarms, personnel become desensitized, leading them to distrust analyzer data or ignore alarms altogether.


“The goal of the smart alarm is to eliminate situations where the operator is told to ignore alarms (like cation conductivity on startup), warn the operator when an instrument is reading incorrectly, perform the troubleshooting of the chemical event to let the operator know what is occurring, and provide troubleshooting guidance. “

– Doug Hubbard, American Electric Power


In contrast, Artificial Intelligence (AI)-based smart chemistry alarms alert operators only when an actual chemistry event – such as a condenser leak or pH excursion – occurs. This gives operators confidence in their alarms and allows chemists to identify specific issues, such as a loss of chemical feed or contamination, while identifying actions operators can take that will prevent damage to steam and water cycle components.

Smart chemistry alarms are a set of chemistry alarm logic that relate real-world chemistry events to multiple chemistry parameter measurement values. They use input from key analyzers, including EPRI Smart Chemistry Alarm logic and IAPWS minimum key instrumentation, and integrate plant- and chemistry-specific limits.

A complete smart alarm system will include multi-parameter measurement/signal inputs, increasing the reliability of the alarms and reducing nuisance alarms. The alarm levels and control bands are plant specific and adjustable, which allow for fine tuning of the system. It also requires at least one analyzer that is from a separate sample point for validation. This prevents a single line sample failure form being interpreted as a real chemistry event.

These alarms are segmented into three main groups:

  • Chemical over/underfeed conditions
  • Contamination conditions (organic, inorganic, acid, caustic, air, sodium)
  • Instrument and equipment issues

Once an alarm sounds, the operator can check the alarm interface to review the actions the system recommends to correct the issue.

power industry-wide impact

This kind of AI-based technology and big data have allowed the power-generating industry to respond quickly to changing variables such as retail and wholesale prices, fuel prices and changes in load. These advances also help plants navigate the challenges of renewable sources, allowing utilities to cycle plants of all types to meet market demand. 

Simplify cycle chemistry monitoring, reduce errors and protect assets with Sentry Equipment smart alarms.


Topics: Power, Liquid & Slurry, Steam & Water

Written by John Powalisz

Picture of John Powalisz
John Powalisz, Director of International Sales, is dedicated to sharing his technical expertise and knowledge of sampling equipment and systems in power plants, refineries, chemical and food processing facilities garnered from more than 19 years with the company. John has worked with clients worldwide to help them to comply with regulations and optimize processes by applying proper sampling hardware and techniques. While he is well-versed in all Sentry products and applications, he is particularly focused on the food and beverage and power generation markets as well as emerging market development.