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Show The most convenient configuration for fuel and FGR connections to the burners are from the left in Fig. 3. The air can either come through the preheater to the burner or from the left if no preheat will be used. One to two weeks are required to install a burner, depending on the extent of modifications. The furnace exhaust is continuously monitored for CO, C02, 02, NOx, N20 and unburned hydrocarbon concentration. The analyzers used for monitoring the exhaust gasses are also used with probes to measure the in-furnace concentrations of these species. A discussion of BERL's conventional and laser-based diagnostic capabilities is the topic of the remainder of this paper. 3.0. Diagnostic Overview This overview of BERL diagnostic capabilities is intended to familiarize potential users with the capabilities and limitations of BERL's diagnostics and also to provide an estimate of the time required for each diagnostic. 3.1 Conventional Diagnostics 3.1.1 Input/output Measurements The purpose of input/output measurements is to examine the efficiency and emission characteristics of burners. Input parameters include: excess air, turndown, staging ratio, combustion air temperature, flue gas recirculation rate and temperature. Both air and fuel flow rates are controlled via a closed-loop system consisting of either mass flow controllers or mass flow meters and pneumatically actuated valves. The combustion air temperature is controlled with an electric resistance heater. Flue gas is taken directly from the stack and pumped back to the furnace with a high temperature blower. Output measurements include: exhaust gas temperature and composition, and heat extraction. Exhaust gas temperature is measured with a suction pyrometer downstream of the conical contraction at the top of the furnace. Exhaust gas is continuously extracted through probe located just downstream of the suction pyrometer. The gas sampling system is described in detail in the next section. Furnace heat extraction is determined through calorimetry measurements on the furnace cooling water. Total heat transfer to the furnace enclosure is calculated from water temperature and flow rate measurements at each of the four furnace cooling water discharge locations. The total heat extraction is controlled by the type of wall panels used and can be tailored according to the burner requirements. Heat extraction from each spool section is estimated from temperature and flow rate measurements from one column of panels. All of the input/output parameters are recorded by the DAS. A spread sheet is used to calculate the furnace energy balance and heat extraction rates. -8- |