Visualization and control of the gas boiler room and HVAC systems at an electron microscope assembly plant in Brno

The AŽD Praha company is a significant and all-Czech producer and supplier of signaling, telecommunication, information and automation technologies. It is mainly focused on the rail and road transport field including telematics and other technologies (quotation from the AŽD Praha website).

During July and August 2011, a control and visualization system was implemented at a newly built electron microscope assembly plant in Brno. The system is designed to control and monitor the plant's gas boiler room and HVAC systems. The investor of the project was MORAVOSTAV Brno, a.s. (construction company). AŽD Praha - Production Plant Brno rents the facility for assembly purposes.

After the agreement with the project's contractor Technoglobal CZ, the Tecomat Foxtrot® control system (produced by Teco, a leading Czech manufacturer of PLCs) was proposed and chosen to fulfill demanding requirements mainly for the control of air-conditioning units (overpressure in clean and super-clean production areas). To control and visualize the HVAC system within the plant, the Reliance SCADA/HMI system was installed. The GEOVAP company was responsible for the supply of the Tecomat Foxtrot PLCs (including the application software), Reliance software, and visualization project.

Control system

The control system consists of two PLCs. One is used to control the operation of the gas boilers. It is installed in the gas boiler room's switchboard. The other PLC is used to control the HVAC system. It is installed in a switchboard located in the technical mezzanine. Both controllers communicate with each other via PLCNet.

To view and control the gas boiler room and the HVAC system using well-arranged visualization screens, the main control room is equipped with a control PC on which the Reliance 4 Control Server runtime software is installed. In addition, two licenses of Reliance 4 Web Client and Reliance 4 Mobile Client are used to allow for remote access to the visualization application.

Detail of the technical mezzanine's switchboard

Based on the data received from the control system, the following is controlled and monitored by the Reliance SCADA/HMI system:

Gas boiler room

• proportional control of two condensing boilers using a 0-10 V signal, which is transmitted to the boiler governor
• control of domestic hot water heating and circulation using a time program
• control of the air-conditioning branch heating (feed pump for air-conditioning heating) and equithermal control of the heating branch in the basement and 2nd story
• monitoring of the equipment status, reporting and logging alarms to a database (operation of the air-conditioning feed pump, overheating and flooding, pressure within the heating system, gas leak, power failure, condensing boiler failure, main gas valve turn-off).

Cooling process

• cooling water source and circulator pump switching systems including cooling the air-conditioning units
• cascade switching of the cooling sources including automatic alternation of the operation and automatic source substitution in the event of failure
• monitoring of the equipment status, reporting and logging alarms to a database (cooling source failure, operation of the cooling circulator pumps, pressure within the cooling system)

Air-conditioning

• air-conditioning unit operation
• control of the air volume and overpressure in the air-conditioned spaces using continuously controlled air-conditioning fans
• control of the intake fan
• control of the ventilation exhaust
• monitoring and setting of the required temperature and humidity using a RCM2-01 interior control module
• monitoring of the equipment status, reporting and logging alarms to a database (clogging of the suction, output, and exhaust filters, operation of the heating and cooling circulator pumps)

Examples of visualization windows

Overview window

Visualization of the boiler room

Visualization of the air-conditioning system

Visualization of the cooling process