초록 ▼

In a staged lean premix low NOx gas turbine combustor, the inside of the combustor is lined with a low density refractory thermal insulator for maintaining the hot face of the lining at or near the flame temperature, i.e., within 200°F. and preferably within 50°F. The heat release value in the first

In a staged lean premix low NOx gas turbine combustor, the inside of the combustor is lined with a low density refractory thermal insulator for maintaining the hot face of the lining at or near the flame temperature, i.e., within 200°F. and preferably within 50°F. The heat release value in the first stage is held at a maximum value consistent with low NOx emission while decreasing the heat release value in the second or third stage to achieve a wide range of turndown. The flame temperature in the respective stages are maintained between a low of 1700°F. and a maximum of 2700°F. The flow of compressed air into the combustor is maintained generally uniform over the entire operating range of 5 to 1 turndown.

대표청구항 ▼

In a method for combusting fuel in a low NOx gas turbine hot wall combustor to provide improved turndown capability the steps of: inducting a premixed lean first mixture of fuel and compressed air into a first stage of a combustion chamber having a thermally insulated inside wall operating near the

In a method for combusting fuel in a low NOx gas turbine hot wall combustor to provide improved turndown capability the steps of: inducting a premixed lean first mixture of fuel and compressed air into a first stage of a combustion chamber having a thermally insulated inside wall operating near the flame temperature of the combustion within the chamber; igniting and combusting the first mixture of fuel and air in the first stage of the combustion chamber to produce first stage combustion products exhausting from the first stage of the combustion chamber; inducting a premixed lean second mixture of fuel and compressed air into a second stage of the combustion chamber downstream of the first stage and into the combustion products exhausting from the first stage of the combustion chamber; igniting and combusting the second lean mixture of fuel and air in the second stage of the combustion chamber to produce second stage combustion products, which include the first stage combustion products, exhausting from the second stage of the combustor; inducting dilution compressed air into the combustion products of the combustion chamber for cooling the temperature of the combustor exhaust; and turning down the total heat release value of the gas turbine combustor from a first value of heat release to a second lower value of heat release by holding the heat release in the first stage of the combustion chamber generally at its maximum value of heat release consistent with low NOx emission while decreasing the heat release in the second stage of the combustion chamber by decreasing the Equivalence Ratio of the inducted lean second mixture of fuel and compressed air, whereby the turndown capability of the combustor is extended to cover a broader range of heat release values while maintaining low NOx emissions.