Error no: 9: Subscript out of range on Line number: 55

Power plant automation at Ruukki: Innovative R&D through close collaboration

When there is a need to improve a process, there is a way to do it. This has been especially true of the long collaboration between Ruukki’s Raahe Works and Metso. Numerous solutions that have been developed together are found today at power plants around the world.

Pls feel free to ask for more information. We also appreciate your feedback in all automation related issues.

The list of ingredients in innovative product development is actually simple. In addition to high technology and process know-how, it includes a thorough understanding of customer needs and a daring attitude on the part of the customer in question.

When Ruukki people and Metso people meet, it’s like old friends getting together: the discussion starts off where it ended the last time. The roots of this fruitful collaboration go back to the 1980s. Since then, Raahe Works’ power plant has acted as a guinea pig for a large number of Metso pilot projects – completely at its own free will with the sole target of improving its power production processes.

The power plant provides electricity and steam for the entire massive Raahe Works area with its many steel manufacturing process stages.

“We have presented Ruukki’s needs, based on which Metso has developed features that we have wanted. A few times Metso has sold us features that have not yet even existed as finished commercial products at that time,” says Tapani Seppälä, Chief Designer, Automation, Investments, Ruukki Metals.

“The people at Ruukki have a lot of know-how and a clear vision of their needs. We appreciate their tremendous courage and open-mindedness in taking part in our pilot projects. They have also trusted our ability to execute things properly,” comments Heikki Mylläri, Sales Director at Metso.

60% electricity consumption covered

The power plant provides electricity and steam for the entire massive Raahe Works area with its many steel manufacturing process stages. There are two power boilers. Boiler No. 3 built in 1975 at 84 bar 525°C. The other one, Boiler No. 4 from 1990, produces 42 kg/s of main steam also at 84 bar 525°C. They are mainly fueled by gas from the plant’s two blast furnaces. Also some coke gas is used as well as heavy oil as spare fuel.

In connection with the power boilers, there are two turbogenerators: TG02 with a capacity of 65 MW/h built in 1975 and TG01 with a capacity of 21 MW/h built in 1963.

Approximately 60% of Raahe Works’ electricity needs are covered by in-house production. 60% of the district heat produced at the power plant and various manufacturing processes is used internally, and the rest is supplied to the town of Raahe.

According to Seppo Kenakkala, Power Plant Manager, there have been plans to build a new power plant. At least for now, they have been put on hold.

According to Ruukki’s Veli Vesikukka (left), Tapani Seppälä and Seppo Kenakkala, there is always some project going on at Raahe.

PLU technique gets rid of separate systems

The cooperation between Ruukki’s Raahe Works and Metso started with small steps in the 1980s and has broadened over the years. One of the first major projects dealt with the automation system of Boiler No. 4 where the single-control unit technology was used as a PLU card application for the first time. And what’s best, the same I/O cards still function flawlessly, although the process stations have been upgraded to modern ACN technology.

According to Seppälä, the PLU technique was a clear competitive advantage when Ruukki chose the boiler automation system for Boiler No. 4. Metso was the only supplier who was able to offer complete boiler automation with one concept. The PLU technology was also applied to the boiler safety system and burner automation for the first time in Finland.

“We wanted an automation system to carry out all power plant automation tasks and to get rid of separate systems,” Seppälä recalls. “Our requirements were high. And we did a lot a work together to integrate the whole boiler automation into the same system.”

Turbine control integrated within the main automation system

After the mid-1990s, the joint product development focused on the introduction of a turbine controller. It was incorporated in the turbogenerator TG01 and featured full integration within the Damatic XD process control system used in those days with the ACU and PLU single-control technology.

However, the beginning was far from promising. The supplier who was in charge of the turbine revision did not trust the new and modern concept of an integrated turbine controller, and some of the Ruukki people did not believe in it either.

“There was a huge amount of prejudice against the idea. In fact, I almost ran out of persons who believed in it any longer,” Seppälä now admits.

A few years later, Kenakkala and Seppälä visited the Energy Fair in Tampere, Finland, and took part in a lecture that introduced a new turbine control solution integrated within the main automation system. The subject sounded very familiar to them; after all, they had been using the solution already for four years... Today, all three turbines at the power plant are equipped with a turbine controller implemented within Metso DNA.

All three turbines at the power plant are equipped with a turbine controller implemented within Metso DNA.

Sensodec 6S to measure turbine vibration

Raahe Works was familiar with Metso’s Sensodec 6S monitoring system as it was used in the motor-driven combustion blower in the blast furnace. However, its measurement cycles were not fast enough for a turbogenerator. Additionally, there was a desire to integrate condition monitoring with the main automation system.

“With turbines, vibration measurements are needed in one-second cycles, since damage can take place fast. The operators must get the alarm early enough,” explains Veli Vesikukka, Development Technician at Ruukki’s maintenance development department.

In the years between 2004 and 2005, the Ruukki and Metso people spent a lot of time developing a mechanical condition monitoring application suitable for turbines. The hard work was successful, and today all large machines at Raahe Works, including both power boilers, are connected to the condition monitoring application.

“We presented the idea of integrating the process automation system, mechanical condition monitoring and field device condition monitoring to Metso already ten years ago. Now it is has become true. Everything takes its own time,” Seppälä continues.

Vesikukka, who uses Sensodec 6S in his daily work especially appreciates the features that are not available in other systems, such as the signal analysis tool. It enables the user to examine the signal in detail and allows him to see, for example, the frequency bands where bearing damage occurs. The system includes 270 sensors to monitor turbine vibrations.

“Sensodec 6S is a reliable tool. The clear and simple graphics enable users to understand the big picture. They know how to pinpoint the damaged part and can go to the process to see it,” he continues.

“Our machines are old, so they need to be monitored extensively. Without monitoring, a turbogenerator can break down completely and cause a lot of damage to its surroundings, too,” adds Kenakkala.

Today, Metso has taken vibration monitoring yet a step further by introducing Metso DNA Machine Monitoring, which offers condition information on all rotating machines for process operators and maintenance staff through one common user interface.

Remote-controlled fresh water supply

Ruukki has also been involved in Metso’s remote application pilot projects. Fresh water needed at the Raahe plant comes from the Piehinki River some 15 km away. There is a dam whose opening is controlled by Metso DNA via a wireless phone network connection. At another location in Pattijoki, there are two dam systems controlled with Metso DNA.

In fact, the long cooperation includes so many pilot protects that it is hard to keep track of them. In this partnership, many good-natured jokes are allowed, too.

“I guess we could say that part of Metso’s product development has its roots in Raahe!” Seppälä remarks with a wide, friendly smile.

Close support from Oulu and Kemi

Time to pose for a partnership portrait. Pictured from the left Jarmo Harjuoja, Veli-Pekka Meriläinen, Seppo Kenakkala, Tapani Seppälä, Veli Vesikukka, Heikki Mylläri, Jyrki Koskela.

At the early stages of cooperation, Raahe Works relied on the Metso people in Tampere. But since the 90s, the contacts and support have been available at a closer distance. The Oulu Sales Office is situated some 70 km, and the Kemi Service Center is some 180 km from the plant.

The companies have signed a service agreement that covers all the automation systems, casting machines, the power plant, blast furnaces and on-call service. The latest addition to the collaboration is the valve storage service provided by Metso. Today, the power plant island is completely automated with Metso DNA.

“Our cooperation has widened over the years. There hasn’t been much silent treatment; instead we have been on good speaking terms all the time. Usually, there is always some extension or rebuild project going on,” Kenakkala points out.

“Long-term cooperation and good personal relationships increase trust on both sides,” Seppälä concludes.

Pls feel free to ask for more information. We also appreciate your feedback in all automation related issues.