Full Automation of Flue Gas Heat Recovery Systems: From Budget Savings to Maximum Efficiency, Safety, and Payback

PAS „Daugavpils siltumtikli“

Daugpilis, Latvia

2024-2025

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Local boiler houses and heating plants are complex technological facilities where every percentage point of efficiency matters. One of the key ways to improve performance is through flue gas heat recovery using condensing and rotary economizers. However, many projects are initially implemented in a reduced form due to budget constraints, when costly full automation is postponed “for later.”

Unfortunately, the heating networks of Daugavpils were no exception. The initial deployment of flue gas heat recovery systems at heating plants was carried out with only partial automation. This decision was driven by budget limitations: the customer focused on basic modernization, postponing the implementation of a complete automatic control system.

Why does initial cost-cutting on automation turn into long-term losses?

Operational practice has shown that the lack of full automation in heat recovery systems leads to several problems:

Heavy workload on staff. Operators are forced to manually monitor and adjust dozens of parameters—rotor speed, damper position, pressure differences. This is not only labor-intensive but also increases the risk of human error.
Equipment risks and failures. Operation in non-optimal or abnormal modes (e.g., uncontrolled icing of the rotary economizer) shortens the lifespan of expensive equipment.
No remote monitoring and control. Management and technical staff lack a complete real-time picture of system performance, making decision-making and efficiency analysis difficult.

For these reasons, in 2024 Daugavpils heating networks decided on a comprehensive upgrade of their flue gas heat recovery systems, which will provide:

Intelligent combustion control based on oxygen content in the flue gases (where not previously available), ensuring maximum fuel efficiency under any load.
Automatic adjustment of rotary economizer speed depending on boiler output, achieving optimal heat exchange without icing risks or unnecessary energy consumption.
Efficient management of air and flue gas flows by partially replacing leaky dampers with fully airtight “Butterfly” dampers and installing electric drives on all dampers.
Modernization of PLC, HMI, and SCADA software to implement complex algorithms for a fully automated cycle: startup, operation, shutdown, and standby mode of the entire boiler unit, including economizers.
Continuous data exchange between all system components, enabling complete remote monitoring and control from a central dispatch panel.

The key takeaway after project implementation:

By postponing automation, companies spend years overpaying for fuel, repairs, and staff costs. Modern projects like this clearly show that investment in an intelligent control system allows you to:

Increase system efficiency by installing fully airtight “Butterfly” dampers. Previously, flue and air ducts used non-airtight dampers. Their poor sealing caused significant leaks: part of the flue gases escaped through the bypass into the atmosphere without releasing their heat, while cold air was drawn into the system, disrupting temperature conditions. The new airtight fittings completely eliminate these losses, directly boosting boiler unit efficiency and enabling flexible, precise flow control.
Improve operational safety.
Extend equipment lifespan through operation in stable, optimized modes.
Minimize human factor impact and reduce operating costs.
Achieve transparency and full control over the technological process.

Stop compromising—unlock 100% of your equipment’s potential with comprehensive automation!