Commissioning of the power plant unit in island operation

The second phase of the contract represents one of our medium-sized projects in the field of process automation for EKOL, one of the last Czech companies able to deliver a complete power plant block according to customer requirements. The end customer has embarked on a major expansion of its sugar and oil processing plant and needs an additional power source for the upcoming expansion. The site is located about 100 km south of the Iraqi capital Baghdad and about 45 km from one of the cradles of civilisation, the city of Babylon.

The first and second phases were interesting because it was a small greenfield power plant, the complete technical equipment of which was supplied by a Czech company. In the first phase, we were given the task of developing a SW standard that should cover such a large automation task as a small power plant (2 boilers, 2 turbines). The first stage was very close to the standard that is represented in automation today by the PCS7 control system from Siemens.

In the second phase, we got the green light for implementation on PCS7. The project used this system to control the technology and the end customer had operational experience with it. The first stage was also important because it resulted in a high-quality visualisation that had no limitations compared to PCS 7. Continuous operation is important for the power plant. This places high demands on the availability and reliability of the control system. Therefore, some of the components of the control system are redundant for the second stage.

Technology that makes a technician's heart beat faster

The power plant we worked on in Iraq in 2019-2021 consists of two heavy oil-fired boilers, each supplying about 100 tonnes of steam per hour to two steam condensing turbines with a capacity of 2 x 20 MW and a speed of 7984 rpm.

The power plant is associated with technologies such as fuel transport, a reducing station to adjust the pressure and temperature of the steam, a feedwater system (two pumps of about 430 kW each), steam condensers, an evacuation system to create a vacuum in the system and much more.

It is a very complex technology that makes the heart of every technician beat faster. And above all there is a control system that corresponds to the complexity of the process. Siemens PCS 7 9.0, which includes 6 Simatic S7-300 PLCs and 5 S7-410 HA PLCs after the integration of the first stage. We also have 2 servers, 1 archive server, one engineering station and after integrating the original system into the new system 8 client stations.

The operator workstations are partially connected to the computers via intelligent KVM switches so that each client workstation can display the image from any computer. After the integration, the local control is carried out via 11 TP- 1500 Comfort touch panels.

The sugar must not solidify!

From a technical point of view, an interesting but also challenging aspect was the fact that the turbines were controlled in so-called island mode. This means that they were not connected to a public network. A fault that results in a power failure would cause a shutdown. The greatest risk is that the sugar in the technology will harden and the losses caused by it will be too high. This places high demands on testing during the commissioning of the technology. The sugar factory must not stand still, the sugar must not solidify!

"The turbine is a technology like any other. You have to have respect for it. We need to know what she forgives and what she doesn't," explains Roman Krejčík, who has been part of our team since 2007. He says he came to the turbines like a blind man to the violins. Originally he wanted to work in the food and beverage industry, but as fate would have it, he became a power engineer and has worked primarily in steam turbine control and commissioning for the past 13 years. In a project in Iraq, he helped in the commissioning of software.

Solution Partnership Siemens

"For energy and large process projects, we want to build on the PCS 7 platform," says in an open interview colleague Karel Tonar, who heads the process automation department where this project is being carried out. The manufacturer's business strategy coincides with ours in that it is geared towards large process projects. The PCS 7 platform is the backbone control system for process automation within the Siemens product portfolio. The system is literally tailor-made for process applications. It is based on standardised libraries and also offers the possibility of making changes during the ongoing operation of the technological processes. It takes process reliability into account and attaches great importance to the long-term availability of all spare parts, because the technologies it has mastered are a long-term investment for its operators. 

"The current PCS 7 is a superstructure over the standard resources available at Siemens and supports the automation of some subtasks that previously had to be performed manually by the programmer. There is also a great procedural library to go with it. There are sometimes disputes among programmers about the complexity and usability of the programme in terms of the necessary parameterisation to achieve the desired functionality. From my point of view, however, it covers all the needs I have had so far when programming the project," comments PCS 7 Šimon Adámek, our external employee and colleague behind the technical solution, who can look back on more than 20 years of cooperation with B:TECH.

Siemens sales manager Petr Buchta adds about the partnership with our company: "We very much appreciate the cooperation with B:TECH. Communication is always open. We are dealing with people who know what they are talking about, both on a business and technical level."

Integration of technologies from the first phase in PCS7

What the customer did not know was that the expansion of the technology would result in a very complex plant that would offer additional possibilities for optimising the entire operation. The individual units were delivered as isolated technologies and were initially regarded as such by the customer. Another interesting task within the project was the requirement to integrate the first stage in PCS 7 and thus connect the technologies with each other. Fortunately, this was possible thanks to an original technical solution. It was an unusual request and a challenge for us. In the end, this plan was successful, even though it entailed additional costs, time and corresponding burdens for the construction site.

In the second phase, these requirements of the operator at the technology level were not originally foreseen. For example, the purchase of additional licences for control panels required to integrate the technologies from the first phase into PCS 7 was not included in the project. The PLCs in the first phase were not redundant, so testing during their integration was quite complicated.

We have made no compromises when it comes to process reliability

The technical solution focused on safety and reliability. So we didn't make any compromises when it came to process reliability. All controllers installed in the second phase are redundant and of the same type. This is also important with regard to the maintenance and operation of the technology. The biggest challenge in this project was controlling the turbine output. In island operation, the systems must maintain the frequency and voltage of the grid even in the event of relatively large outages or increased power consumption.

"It turned out that the controls installed in the first phase did not fully cover the plant's needs. In the event of sudden power failures, the turbine generators were unable to reduce their output and frequency protection failures occurred. The hardware limitation of these controllers was that the speed data arrived with a certain delay via the Profibus. The controller's software solution was not ideal either," Šimon Adámek adds and explains how we used the experience from the first phase.

A small Czech championship

In the second phase, we mainly dealt with the hardware limitations and tested the new type of ET 200SP HA cards with regard to measuring the communication speed. The original tachometers communicate via a 4-20 mA current loop. We had to check whether these cards could handle the measurement of this analogue signal in a 25-ms cycle, which was confirmed. Another challenge was the actual regulation and its concept to really cover all the needs of such a complex and networked technological entity.

Jan Kváč adds an interesting fact to the technical solution: "In this project, B:TECH also won a Czech first prize. It was the first time that a Czech company used the ET 200SP HA input and output units on this project. At the time, it was a new solution in process automation in which the decentralised input/output units communicate with the CPU via the Profinet bus instead of the widely used Profibus standard. This solution based on the Profinet communication bus was one of the first in the world, and it is great that this project is being implemented by a Czech company."

It doesn't matter what your T-shirt says, we're all a team

Such complex projects involve a truly diverse team of specialists from several companies across the supply chain, including external collaborators. "At the end of the day, it doesn't matter what the T-shirt says, we're all a team on the site and have a common goal. Put the power plant into operation," explains my colleague Roman Krejčík at the construction site.

The challenge was also the location

One of the challenges of this project this time was the location in Iraq. The travel and working conditions were difficult and dangerous. This does not only apply to trips that are characterized by security measures, the political and security situation and the standard of living at the destination. Climatic conditions also played a role. Daytime temperatures were between 40 and 50 °C in some parts of the year, dropping to 30 °C overnight.

"The security situation was much better in 2020. Nevertheless, the sugar factory was protected by soldiers. We also had an armed escort on the way to the airport," recalls Roman, who took part in the technology commissioning and repeatedly went to the construction site for 2-5 weeks.

In the cradle of civilisation

Iraq is one of the cradles of ancient civilisations. The sugar factory is located about 30-40 km from the remains of the ancient city of Babylon, which the colleagues were able to visit. Travelling to such places is physically and mentally exhausting. The fact that they get to see places that you normally cannot go to is perceived by colleagues as one of the opportunities that this profession brings with it. The opportunity to discover new places from a non-tourist perspective.