OCR Text |
Show 2 Below shown are the requirements in developing the burner. Table 1 indicates the development objective of the burner. 1) Stable combustion must be obtained in exhaust gas having a low 02 concentration, and combustion must continue at the maximum combustion rate until the remaining 02 concentration becomes 3% (dry). Fig. 2 shows unstabability of firing at low 02 concentration. 2) At low burner load this burner should be fired stably by large amount of excess exhaust gas because gas turbine is operated at maximum load. 3) This burner must be operated not only with gas turbine exhaust, but also with fresh air (02 = 21%) during the regular inspection of gas turbine. 4) NOx emission must be low in the whole burner load. 5) The burner exhaust gas differential pressure of the burner must be low, because the gas turbine has the upper limit of back pressure. 2. Experiment and Equipment 2-1 Experimental Equipment In Fig. 3, a flow chart of the experimental equipment is shown. As a substitute of the gas turbine exhaust gas, we used combustion exhaust gas of generous gas burner with excess air. By changing firing rate and air ratio of the burner for the mock gas turbine generating device with D1-D3 dampers, we set up 02 concentration of exhaust, and then the fixed temperature with D4-D5 dampers. Further, by mixing steam into the gas turbine exhaust, we set up the composition of H20 content. In Fig. 4, a structural drawing of test burner is shown. Since the burner is fired wi th both gas turbine exhaust and fresh air, we divided the exhaust gas entering part of burner into two stage, its secondary damper is closed when firing with fresh air, and the burner is fired by supplying fresh air only to first stage. 2-2 Contents of Experiment In Fig. 5, exhaust gas composition of typical gas turbine which generation capacity is 1,000 kW to 6,000 kW is shown. From this figure, exhaust gas composition of the gas turbine is made at 500°C and approx. 15% (dry) of °2 • (1) Elementary Experiment Conditions for gas turbine exhaust is set up with 4,000 Nm3/H (wet) of exhaust gas quantity, 500°C and 15% (dry) of 0 2 and we examine at the condi tion that the maximum burner firing rate is 2,300 kW. We have examined the shapes of gas nozzle and swirler of the burner for stable firing and low NOx level. |