Objective
The main aim of the project is to increase energy efficiency in the chipboard production process by enhancing the useful value of the wood waste through its conversion in electricity. The Integrated Energy System has been designed in such a way that, complemented with a new top cycle combined heat and power application, a yearly primary energy saving of 19.594 toe can be achieved what will lead to a cut of the energy cost by 100% and obtaining a net income (excluding operating and maintenance costs) of 630 MESP mainly due to the exported power while improving the environment and increasing product quality and energy supply reliability. A proper performance of the whole system should be demonstrated. In this subject a high efficiency and availability of the heat recovery system must be reached, even taking into account the extremely difficult conditions of the flue gases. The scheme will also improve the environment by lowering the CO2 emissions by 82100 tons per year.
The Design, Manufacture and Assembly/Installation/Erection phases of the project have been fully completed and most of commissioning. The monitoring phase is ready to start.
The Dryers operating with hot gases from the Turbine have been put into service in an optimum fashion, and operating control of the Dryers themselves has presented no problem whatsoever. Likewise, an improvement has been observed both in the quality of the product upon elimination of the impunities in the gases that were accumulating on the boards and in the operational availability of the plant.
Taking full advantage of the surplus heat of the Gas Turbine gases not used in the Dryers has proven somewhat difficult at times of operation when the demand of the dryers is such that the large gas bypass valve that regulates pressure in the ducts system in their unstable zones must be controlled (Valve openings less than 10%). Slight changes in the position of this bypass valve can lead to excess pressure in the duct which causes it to open completely (to ensure Gas Turbine safety). This drastically reduces the flow sent to the boiler. Operation of the Incinerator and Dust Combustion Chamber gas recovery system has led to constant problems. This has impeded its start-up, since neither a stable operating regimen nor the projected production levels have been achieved. The following are the more important problems that have arisen:
- When the Incinerator was started, pressure built up in the Combustion Chamber, impeding its proper functioning. This was due to the insufficient draw of the induced draft fan of the Incinerator Recovery Boiler, which was unable to evacuate all the waste gases of the Dust Combustion Chamber and the Incinerator at the same time. This problem weas solved by converting the all/nothing valve of Incinerator gas exhaust to a modulating valve. In this way, the flow of gases leaving the Inicnerator can be controlled and, therefore, the pressure in the duct to the Boiler aswell. In any event, we have seen that the induced draft fan is insufficient to remove all heat energy effluents produced, since the actual system exhaust losses are much higher that foreseen. A new fan to replace this one is currently being designed.
The dust and ash from the Incinerator gases are depositing faster than expected in the Boiler, thus progressively decreasing the heat absorbed in it. The installation of a cleaning system that would impede the depositing of ash in the pipes is currently under study.
The system also suffers from changes in temperature at furnace exhaust, which at this time ranges from 400 deg. C to 850 deg. C over short periods of time. The cause of this variation is a fluctuation in the demand for thermal fluid and the control that this demand exercises over the incinerator furnace temperature. The problem should be solved by increasing secondary air to the furnace in order to stabilise its temperature, and by increasing the capacity of the induced draft fan.
The project consists of an Integrated Energy System which embraces a top and bottom cogeneration cycle on one sole plant and whose commissioning will mean the energy optimization of the plant, the betterment of the environment and the maximum flexibility in the manufacturing process of the chipboard.
The system is based on the incinerator of the waste from the existing process, which would have to be modified for is adaptation to the requirements of the new plant and which is complemented by a gas turbine (18 MW). The way that the system operates involves that the supply meets the demand for thermic fluid by means of heat obtained within the incinerator, covering the needs of the dryers with the exhaust gases emanated from the gas turbine.
The heat excess resulting from the previously described processes, which is very variable, depending on the process demand, is made use of by means of a transformation process into steam. The operation and control of the integrated energy systemis technically complex, owing to the fact that the availability of clean gases from the turbine and dirty gases with a high content of silica and ashes, originating from the waste incinerator, is added to the variability of the temperatures, gas stream and composition of the gases passing through the units.
As result of these determining factors during the design phase, the splitting of the Heat Recovery System has been adopted as and end solution, with independent recovery of surplus heat from available sources, the Incinerator and the Combustion Turbine.
The steam produced in both heat recovery boilers, is used for the production of additional electric energy (6 MW), in a steam condensing turbine. Thus the energy efficiency of the system is maximized but, in the other hand, the integration of steam produced in different heat recovery boilers results in a more complex control due to the facts of its different operating conditions depending on the level of steam produced in eachboiler. The gas turbine will use natural gas as fuel. Taking into consideration that the site does not dispose of channelized gas, provision has been made for its supply in the form of the liquefied natural gas, which will be transported by tank truck to the factory in Cella, regasifying it on-the-spot by means of hot water produced in the condensator of the steam turbine.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
- engineering and technologyelectrical engineering, electronic engineering, information engineeringelectrical engineeringelectric energy
- engineering and technologymechanical engineeringmanufacturing engineering
- engineering and technologyelectrical engineering, electronic engineering, information engineeringelectrical engineeringpower engineeringelectric power generationcombined heat and power
- engineering and technologyenvironmental engineeringenergy and fuelsfossil energynatural gas
- agricultural sciencesagriculture, forestry, and fisheriesforestry
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Call for proposal
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DEM - Demonstration contractsCoordinator
28016 Madrid
Spain