Heating Function Blocks for Safe Energy Transition
Germany is facing unprecedented challenges as a result of the energy transition. Infrastructures established over decades have to be dismantled to tackle climate change and become geopolitically less dependent on fossil fuels. An important element of this transformation is to update the technical equipment and processes of existing heat generation plants to the state of the art. This is showcased by a project of MVV Energie AG that uses a cutting-edge safety system from HIMA.
While the current focus is on power generation using renewable energies, one area has taken a back seat: the heating market. Quite wrongly, though, because the consumption of energy for heat generation is the largest item in the German energy balance, accounting for more than 50 percent of the total – significantly more than electricity and mobility. 60% of the energy consumed is required to heat rooms and water, the rest is used for industrial process heat.
A successful energy transition will also require a number of different measures in the heating sector, from building renovation to improve energy efficiency, decarbonizing heating systems, increased use of solar thermal energy, transformation of district heating systems, intelligent use of industrial waste heat, to construction of large-scale heat pumps and geothermal plants. In fact, energy suppliers have to manage a value chain that is becoming ever more complex.
Existing Systems Have to Be Optimized Continuously
In addition to creating new systems for energy generation and distribution, providers can also optimize their existing systems, from combined heat and power plants to thermal waste treatment. One example of this is the thermal waste treatment plant, including the associated flue gas cleaning, at MVV Energie AG's Mannheim location. The energy company wants to become “climate positive” from 2040, i.e., actively remove CO2 from the atmosphere. The thermal waste treatment plant in Mannheim produces electricity, heat and process steam for the local industry.
“Our systems must be state of the art to ensure reliable and safe heat supply to our local industrial customers,” says Roger Funk, Group Leader at MVV Umwelt Asset GmbH, which is responsible for planning, building and operating power plants in the MVV Group.
HIMA Supports Project Management
Any intervention in the energy infrastructure requires the relevant expertise. MVV therefore contracted HIMA to replace the existing burner and boiler protection control systems at its facility.
“Replacing the burner and boiler protection control systems in one of our thermal waste treatment plants is a technically highly demanding project; that was clear right from the beginning of the planning phase. This is why we contacted HIMA very early on, who supported us in assessing and specifying the necessary measures,” explains Roger Funk.
The work started with HIMA assessing the safety equipment of the waste boiler. Thermal waste treatment is carried out by means of grate firing supported by four support and four superheater burners each in the boiler and superheater sections. The associated steam generator works with a capacity of approx. 100 t/h hot steam at a pressure of 64 bar and a temperature of 430 °C.
“In this area, we replaced some devices, such as discontinued models of burner control systems or measuring devices,” says HIMA Application Manager Karl-Heinz Kruse, describing the first steps.
During the project, the HIMA Applications Team installed new components, such as flame detectors and ionization relays, and networked them via a HIMA controller from the HIQuad X family.
“While we agreed on the concept and specifications early on with the team from MVV in the safety assessment, fine-tuning the logic concepts was one of the main tasks,” adds Karl-Heinz Kruse.
Safety for Multi-Burner and Multi-Fuel Systems
Thermal processes and steam generators need safety-relevant control systems to ensure reliable and highly available fuel use and optimal boiler protection. MVV therefore opted for the BCS/BMS solution from HIMA, which is designed for multi-burner and multi-fuel burner systems. It ensures operation with the widest variety of fuels and residues. Users benefit from the fact that the solution combines safety technology, process technology, start and stop sequences and a programmable SIL 3 control system that makes sure that all safety and availability requirements are met by the plant. Such an integrated solution saves on valuable time, both during planning and implementation of the retrofit, as well as during later maintenance and repair work. In addition, it permanently lowers operating costs.
“We successfully commissioned the new system at the end of 2021 and are now enjoying reliable and safe burner control system operation,” says Roger Funk and adds: “The sustain of the operation release was ease by the TÜV approved system and used software macros. We've also noticed that the availability of the burner control system has once again increased significantly.”
MVV Energie AG
With about 6500 staff and an annual turnover of around 4.1 billion euros, MVV is one of the leading energy companies in Germany. MVV covers all steps of the energy value chain, from energy generation through energy trade and distribution via the operation of distribution grids, up to sales, environmental and energy services business. The company is a pioneer in energy transition and has committed to a strategic path in its “Mannheim Model”. The aim is to become climate neutral by 2040 and then move on to become one of the first German energy companies to be climate positive. In doing so, it consistently embraces the heating transition, the electricity transition and the related increase in renewable energies, as well as green products and solutions for its customers. Its climate goals follow the 1.5 degree path. This has been certified by the international “Science Based Targets Initiative” (SBTi). According to the renowned rating agency ISS, MVV is one of the top four energy companies worldwide in terms of sustainability. MVV is a company in the Rhine-Neckar metropolitan region, the MVV Group is active worldwide.
- Consulting and planning
- Preparation of safety-related assessment
- Preparation of logic concepts for the safety and combustion technology
- Implementation of boiler protection
- Pre-ventilation for the boiler and flue gas passages
- Protection for burner and flue gas cleaning system
- Protection and leak test for the load and superheater burners, including the safety-relevant sequence of operations
- Acceptance and inspection of the modifications as well as the newly installed system by the TÜV
Hydrostatic fill level measurement is widely used to measure the water level in large capacity water boilers. The benefits of this measurement method combined with the use of a differential pressure transmitter and a pressure gauge, result in robust, accurate and reliable fill level measurements.
Safety-related requirements can be met using single-channel or multi-channel SIL-certified transmitters. The measurement procedure is challenging for the safety-related control system in that you must calculate the densities for steam, water and the reference column, respectively.
In particular, the algorithm for the fill level measurement must be specific to the application. HIMA's BCS application also masters this measurement method with high precision, so it was no problem to renew the three hydrostatic level measurements on the boiler.