201802_Renewable Energy
17/24

The water is fed into the boilers by three pumps (one per line, plus one standby pump) that deliver a maximum flow of 120 t/h at 100 bar.In all of these processes at this WTE plant, safety is the top priority. A robust and reliable integrated control and safety system (ICSS) made up of the CENTUM CS3000 PCS and the ProSafe-RS SIS ensures safe operations while fully automating key processes such as the supply of combustion air and feed water while ensuring that the combustion temperature never falls below 850 deg. C.The boiler emergency shut down function is configured in ProSafe-RS, which features the same engineering environment and HMI screens as the PCS. Working from their HMI stations in the central control room, operators enjoy ready access to information on processes throughout this facility and are able to take timely and correct action to ensure safe operations at this facility 24/7/365.Environmental sustainabilityTo safeguard the environment, all flue gases are care-fully treated before being released out the stack. Exiting each boiler at 180 deg. C, the flue gases enter a gas treatment system that employs a gas cleaning line (one per incineration line) with a nominal flow of 145,000 Nm3/h). This is a semi-dry scrubber(Turbosorp) that works in combination with a fabric bag filter and a high-temperature SCR DeNox system.The acid gases are neutralized in a turbo reactor and dry activated carbon and calcium hydroxide are injected to absorb heavy metals, dioxins, and furans. The gases then go to the bag filter, which separates all the products created by the preceding reactions. Subsequently, the gases are heated by heat ex-changers to a temperature of 250 deg. C and nitrogen oxides are eliminated by the addition of ammonia in the presence of a catalyst (the SCR DeNox process). Finally, the completely clean gases are released through the stack at a temperature of 170 deg. C. A variety of analytical instruments accurately measure the concentrations of key components, and this data can be monitored and controlled by the Yokogawa PCS. This data is also gathered by the Yokogawa Exaquantum PIMS for reporting and further analysis to ensure the sustainable operation of this WTE facility.Minimal use of landfillA fly ash stabilization facility is installed in the flue gas cleaning area to treat and store the incineration residue. Once the ash has been inerted, it is sent by truck to a controlled safety landfill located adjacent to the facility. The other by-product of incineration is slag, which is formed mainly from the arid, ferrous, and nonferrous waste fractions. The slag falls at high temperature from the furnace grates to a bunker. From this pit, it is collected by a gantry crane and unloaded onto a vibrating screen. At an adjacent plant that is capable of handling 120 tons of slag per hour, the slag is converted to materials that can be used in cement production and road construction.Customer SatisfactionSimon Gili Planas, project manager: “Our WTE plant has four main processes: waste treatment, the water-steam cycle, energy generation, and slag treatment. Thanks to the integration of the ICSS with sub-systems like the Siemens steam turbine, crane system, and SCR DeNox system, our personnel in the central control room are able to keep tabs on operations throughout the entire plant. Yokogawa’s systems and non-system products have proven to be very reliable, and we are very happy that there have been no major systems related problems and that we have been able to keep the plant operating nonstop year-round. This helps us comply with the urban waste master plan for Mallorca and with national waste handling guidelines. Our data are always well within European standards as well.”Diego Rodriguez-Losada Sada, staff member, maintenance department: “Our ICSS is working nicely and is easy to operate. Engineering for the PCS and SIS can be done from the same engineering work station. This reduces workload and helps prevent mistakes. The Plant Resource Manager (PRM) asset management package collects data from the FOUNDATION™ Fieldbus field devices. Maintenance engineers can easily confirm all the parameters and diagnostic data for these field devices in the device viewer window, and schedule field device checks. This allows us to take a predictive maintenance approach.”HMI stations in central control roomImportant environmental data is continuously displayed on the large screen in front of the HMI stationsSlag treatment facility (left)Waste amount TonsGross energy MWhWhen a field device is replaced, all relevant parameters can be seen quicklyMaintenance engineers can easily access the PRM systemSuccess Story Collection14TIRME / Spain

元のページ  ../index.html#17

このブックを見る