Visualization and control of the processes of cooling air compressors and heating hot water at Dalkia Industry CZ

Dalkia Industry CZ is a member of the Dalkia in the Czech Republic Group. This company is an exclusive supplier of electricity for industrial activities of its main customer – OKD –, the only producer of black coal in Czechia.

Dalkia Industry CZ provides the supply and distribution of electric power, the production and distribution of heat, hot water, and compressed air, and also provides cooling for OKD-owned mines through production and distribution devices that are largely located close to the mining sites.

Between 2010 and 2013, the devices for the supply and distribution of electric power and for the production of heat, hot water, and compressed air were reconstructed and renovated. The technology of the recovery of waste heat from Atlas Copco compressors was also renovated as part of the reconstruction. The control and management layer of the technology was implemented by Autel.

The compressors are used to produce compressed air that flows through pipes into a shaft to power pneumatic actuators in an explosive environment, shearer loaders, or jackhammers. Depending on the size of the shaft, they produce 5,000–50,000 cubic meters of compressed air under a pressure of 3–5 bar/h with an output of 1–5 MW.

When running, such high-performance compressors produce a great amount of heat and, therefore, must be cooled. They are cooled by a complex system consisting of water pipes, cooling radiators, exchangers, refilling tanks, and cooling towers. Mainly water is used as a coolant.

To maximize the efficiency of the mining operation, the cooling system is also used to heat hot water for hygiene purposes.

Control system

The processes of cooling the air compressors and heating hot water are controlled by five control systems (2 x Siemens, Micromaster, Unitronics, and SAIA). To clearly visualize these processes, the Reliance SCADA/HMI system is used. It is installed on the operator's PC. The control system communicates with the Reliance SCADA/HMI system via Ethernet.

The operating personnel can view and control the following processes:

• Cooling Atlas Copco compressors
• Fluid cooling using cooling tower fans
• Heat transfer in plate heat exchangers and cooling radiators
• Coolant flow in collectors and distributors
• Air-compressing plant lighting
• Hot water heating
• Heating
• Filling and emptying the refilling tanks

Examples of visualization windows