Control system of economizer for boilers in JKP „Toplana“ Šabac
During the 4th phase of Serbian heating plants rehabilitation project, which is financed by Federal Republic of Germany Government through KfW bank program, at  JKP „Toplana“ Šabac in „Trkalište“ heating plant the three boilers were reconstructed by installation of economizer units.„Remming d.o.o.“ company from Novi Sad, reputable manufacturer of boilers and thermal power process equipment, which got the tender, engaged our company as a perennial and reliable partner for realization of economizer control system.

Purpose of economizer installation on three existing steam/hot water boilers 14MW, was to efficiently use the power of burner by using heat of exhaust gases. In that way savings in the JKP „Toplana“ budget and end-user  budgethave been made. Backwater from consume network is transported to mixing valve through ON/OFF electromotive ball valves and circulating pump. Depending on external temperature  mixing valve has to, , mix backwater and water heated in economizer at certain ratio. That way the set value of water temperature coming into boiler is reached. Furthermore, required power of burners is reduced (proportional to the difference between desired temperature of water going out from boiler and temperature of water incoming into boiler). 

Beside automatic mode which has been described, the economizer control system allows users to choose mode which prevents water freezing (when the burners are off, and the external temperature is very low, circulating pump and mixing valve are heating hydraulic installation which is located outside), and also manual mode (optionally, in case of tests or maintenance).

   economizer   economizer

Control system of economizer for boilers in heating plant „Trkalište“, JP „Toplana“ Šabac, is based on programmable logic controller (PLC) produced by Omron, CJ2 Series, and on operating colour „touch-screen“ panel, NB Series, 5.6.  
Processing module supports programming language standard IEC61131-3: Structured Text (ST), Sequential Function Chart (SFC) and Ladder. Function blocks library, predefined and tested, related to common technological unities, significantly reduces time required for programming of the application. As a part of control system there is also ultrasonic measurer of heat (“calorimeter”), which exchanges information with PLC through RS485 / RS232 communication interface.

  control system

Extent of finished work and the effects

Project realization of control system for new boiler room by Mikro Kontrol includes these phases:
  • Elaboration of as-built project documentation and as-built design
  • Production, delivery and linkage of distribution cabinets
  • Performing electrical wiring in facility (cable routes, broaching and connecting cables)
  • Selection, delivery, programming and commissioning of PLC and HMI control system

During the realization of these steps following profiles of workers were enlisted:
  • Engineers in project bureau and on the field (300 engineer-hours)
  • Electromechanics in workshop and on the field (500 mechanic-hours)

Realization of economizer control system has been performed during the heating season, therefore the goal was to provide continuous delivery of thermal power to consumers. Because of that, time required for performing works on each of three boilers had to be minimized, so that in every single moment at least two of three boilers were available.
By installation of economizer and adequate optimization of control system parameters, significant savings were achieved in the budget of customer (JKP “Toplana”) and consumers using remote heating system in Šabac.


Vase Pelagica 30
11000 Belgrade, Serbia
+381 (0)11 3699 080
+381 (0)11 3699 939
Powered by BeoNET