Optimal Control of Heat Generation and Distribution

It is estimated that more than 90% of control systems currently operating in the food and chemical industries do not perform optimally. In particular, they fail to provide the required level and quality of control for heat generation and distribution processes. This results in increased energy consumption, greater environmental impact, and excessive production downtime. The PID controller, the most commonly used industrial control solution, rarely delivers high performance due to improper tuning or an inefficient control structure.

“One way to improve the efficiency of industrial processes is through effective control of heat distribution and exchange systems, which are often key components of industrial installations,” emphasizes Michał Frątczak, PhD Eng., from the Silesian University of Technology.

Advanced modeling and simulation methods for heat generation and distribution processes are employed throughout the project.

The research project is being carried out using a heat distribution and exchange installation located in the technological laboratory of the Department of Automation and Robotics at the Faculty of Automatic Control, Electronics and Computer Science of the Silesian University of Technology. The laboratory setup includes an electric flow heater with modulated heating power and a configurable system of two plate heat exchangers. The facility is equipped with industrial temperature, pressure and flow sensors, as well as control valves that regulate liquid flow through the heater and both heat-exchanger circuits. This configuration enables the simulation of a thermal substation with a controllable heat source and a configurable set of heat consumers.

The project has been divided into five stages. The first involved developing a method for tuning process-model parameters and designing the IT application architecture. In the next stage, the research team developed a control algorithm together with an automatic retuning method, allowing adaptation to changing production conditions during operation. The researchers then designed a control system for an industrial flow heater and subsequently developed the dpB-BAC controller to regulate water flow in the primary circuit of a heat exchanger. Based on a process model and requiring dedicated tuning methods, the controller enables highly efficient system operation.

System D-ACS pracuje w oparciu o komputery EDGE Siemensa lub chmurę obliczeniową.

The third stage of the project focused on evaluating control performance in heat generation and distribution systems. The outcome of this phase is an automatic control performance assessment system implemented as an application on the Industrial Edge platform and connected to a PLC controller. Based on measured process variables, the system provides operators with information about control quality.

“The system has been designed so that it can also be used in existing control installations with implemented algorithms such as PID controllers, significantly increasing the versatility and practical applicability of our solution,” explains Michał Frątczak, PhD Eng., from the Silesian University of Technology.

The fourth stage of the project, carried out in mid-2024, involved integrating the previously developed solutions and performing laboratory validation of the complete system. This phase employed a virtual commissioning approach. It enabled the consolidation of the methods developed during stages 1–3 through the implementation of the advanced controller function block and its integration with digital twins created in the SIMIT application. As a result, a unified autonomous control system was developed, based on a Siemens S7-1500 PLC and an Edge computer. Its operation was successfully validated using virtual commissioning techniques.

The final outcome of the research project will be verified during the last stage, scheduled for the fourth quarter of 2024, when the system will be tested under real industrial operating conditions.

The Siemens SIMATIC ET200eco distributed I/O modules with IP69K protection used in the project collect data from field sensors. Thanks to their ability to operate outside control cabinets, they can be installed directly next to sensors, reducing cabling requirements. Their enhanced resistance to harsh environmental conditions makes them particularly suitable for food and chemical industry applications, where the system is intended to operate. Support for the IO-Link protocol provides standardized connectivity with a wide range of field devices that may already be installed at customer sites.

The solution also incorporates the Field Data Enabler PN App, which can transparently read data from IO-Link devices without requiring modifications to the PLC program. This provides an alternative method of acquiring process data within the system.

“By using this approach, integration with a customer’s actual installation does not require interference with often highly complex and business-critical control programs, nor the need to obtain additional approvals from machine manufacturers, which can be difficult to secure. This concept provides a strong foundation and high flexibility for the system while ensuring stability and compliance with industrial application standards,” adds Mirosław Kuligowski, Sales Development Manager at Siemens.

The operation of the entire system was verified using digital twin technology.

The efficient operation of heat consumers has a significant impact on improving the energy performance of entire installations and also enables lower production costs in industrial plants. The solution developed by the team at the Silesian University of Technology, which uses programmable controllers and an IT infrastructure tailored to customer requirements, can support the modernization of many control systems that currently operate in a suboptimal manner.

“The process control system for heat generation and distribution developed at the Silesian University of Technology uses IT technologies for advanced control, making it possible to optimize many aspects related to energy consumption and carbon dioxide emissions. As a result, it can significantly help bridge the gap between industrial reality and Industry 4.0 technologies, while the use of the Industrial Edge platform ensures continuous and reliable operation,”
summarizes Artur Nowocień from Siemens.