(energy central 400+) Marketable energy central from 400 kW with innovative, simple electricity conversion for residential building, public utility and commercial objects
Typically, biogenous "residuals" can only be utilized with difficulties or have to be landfilled or disposed in different ways. The combustion of biogenous "residuals" in conventional biomass-fired combustion plants is usually not possible or results in significant technical complexity. On the other hand, thermal utilization of biogenous "residuals" can be applied for the generation of heat (cooling energy) and electric power and thus, contribute to a large extent to the necessary carbon dioxide savings.
The motivation was primarily based on the high potential of market demand in the area of heating large-volume residential buildings in municipalities and urban expansion areas, as well as in the replacement of existing fossil combustion units and in the export business.
Contents and Objectives
The target of this project was the development of a marketable, decentralized "energy central" on a scale from 400 kW for the generation of electricity, heating (and cooling) with a broad variety of applicable fuels on the base of regionally available biogenous residual materials.
Within the framework of an experimental development novel solutions for the additional requirements on the process control concerning various fuels have been elaborated. Additionally, the stabilization of the combustion process for supporting the electricity production as well as the optimization of the emission behavior of the combustion process were treated.
The functional and operational reliability of the novel technology was demonstrated under real-life conditions. The historic castle "Schloss Leiben" was supplied with heating energy and electrical power was injected to the public grid provided by EVN. Thus, the realization of short transportation routes for fuel supply applying decentralized plants as well as utilizing regional available biogenous fuels from nearby fallow areas were demonstrated. Moreover, a high degree of independence to raw material price fluctuations was reached due to the broad applicable biogenous fuel band.
Due to the significant carbon dioxide savings together with the advantageous emission behavior and the high energetic efficiency of the novel and patented combustion technology, a fast international spreading of the technology, especially within CEE-countries, was expected.
The aspired targets and results - realized with a marketable, compact and decentralized "energy central" of 400kW (heat and power) - were achieved in the final research step.
Together with conducting combustion experiments, a detailed CFD-analysis was performed in order to determine the final plant design and to optimize fluid dynamic aspects within the plant. For this purpose, detailed models for turbulence, heterogeneous combustion and coupled mass and heat transport were applied. After achieving a successful modeling of the experimental findings, the verified and parameterized simulation model was used for the optimization of combustion chamber geometry and operational parameters. Additionally, the results of the CFD-analysis together with simple chemical engineering balancing tools were used to guide the development of the control system of the real plant.
Parameter studies were used to elaborate the interdependencies of various control variables and to design physically closed control loops. Furthermore, the parameterization of the PID cycles for the design of stable control loops for various operational regimes was supported.
The combustion plant has successfully been transferred to its new location and has been connected to the existing piping system. Furthermore, the infrastructure necessary for a smooth plant operation has been built up. All measurement and control components have been tested and verified. The process visualization has been adapted to the needs of the new plant location. The results of the combustion experiments show a fast availability of the combustion plant together with favorable combustion characteristics of the used biogenous fuel. It has been shown, that the given emission limits concerning the combustion flue gas have not been exceeded during the combustion experiments.
The system was successfully installed at the location and connected to the present grid system. During the project, the necessary infrastructure for the operation has been built to ensure a smooth running of the system. Any measurement and control components have been checked and tested extensively. The visualisation has been adapted and revised for the site. The results of the test runs showed a rapid deployment of the system with good combustion properties of the biogenous fuel used. The experiments have demonstrated compliance with the prescribed limits of the exhaust gas under operating conditions.
The plant is currently in the advanced trial operation phase. The heat demand of customers Leiben castle and "Meierhof" is currently lower than the thermal rating of the "Energy Centre". An operation of the power station at full load is only conditionally possible or during short periods. A review of the plant operation and the emission situation can be made nevertheless based on previous results.
The start of the incinerator by the ignition of the fuel bales runs smoothly. The individually adjustable air flow simultaneously also enables comparatively low down times and rapid load changes. These are substantial system characteristics, resulting in significant advantages in the evaluation of the combustion system.
Summing up, the "Energy Centre" in the decentralised scale has significant advantages regarding energy, emissions and operation compared to other energy systems. Minor adaptations of the fuel rack system, the automation of grate system and ash extraction and a user friendly adjustment of the operating software are performed during an "extended test operation phase" in order for the system to reach a marketable status.
Prospects / Suggestions for future research
Applying the further developed and optimized combustion plant a simple and economic technical solution for a broad application spectrum will be realized for example for the coupled production of heat and power or for the supply of process steam in heat-intensive industrial drying processes. The novel technology even allows the thermal utilization of inhomogeneous biomass fuels.
Furthermore, an enhancement of raw material and energy efficiency as well as a reduction of the dependency on foreign energy carrier supply will be facilitated as the novel combustion technology allows using a broad and cost efficient biogenous fuel spectrum.
Prospective customers regularly visit the demonstration site "Energiezentrale400 +". Both project partners are jointly updating the business plan for a production of the "Energy Centre" on an industrial scale. Serious discussions already take place with potential investors.
Ing. Heinz Dötzl
Federspiel Ökotechnology Consulting GmbH
Project or cooperation partners
- WTI wärmetechnische Industrieanlagen Gesellschaft m.b.H. (project partner)
- TU Wien, Institut für Verfahrens-, Umwelttechnik und Technische Biowissenschaften (scientific partner, participates in the project as subcontractor)