Reinforced afterburning type combined cycle waste heat boiler

Abstract

The utility model relates to the technical field of boilers, in particular to an enhanced afterburning type combined cycle waste heat boiler, which can realize the maximum continuous evaporation capacity of the boiler, comprises a combustion chamber and a horizontal flue, and is characterized in that an afterburning burner nozzle is arranged in the combustion chamber; the horizontal flue is sequentially divided into a first flue, a denitration area, a second flue and a third flue in the flue gas flowing direction, a high-pressure evaporator and a high-pressure superheater are arranged in the first flue, a high-pressure economizer, a low-pressure superheater and a low-pressure evaporator are arranged in the second flue, and a low-pressure economizer is arranged in the third flue.

Description

TECHNICAL FIELD

[0001] The utility model relates to a boiler technical field, concretely is a kind of strengthen supplementary combustion type combined cycle waste heat boiler. BACKGROUND

[0002] The configuration of conventional gas turbine combined cycle unit is usually gas turbine-waste heat boiler-steam turbine, and the waste heat boiler directly receives the exhaust gas of gas turbine for working medium heat exchange without combustion process. Because the boiler directly receives the exhaust gas of gas turbine, the steam parameters of the boiler are limited by the exhaust gas temperature and flow of the gas turbine. For a certain domestic AGT25 type gas turbine combined cycle project, the exhaust gas temperature of the gas turbine is relatively low (the exhaust gas temperature is 450 DEG C~500 DEG C under full load condition), but the main steam parameters of the boiler are required to be relatively high (the high-pressure main steam temperature is 540 DEG C, and the main steam pressure is 13. MPa), and the steam parameters required by the boiler cannot be reached by simply relying on the exhaust gas of the gas turbine. SUMMARY

[0003] To solve the above technical problems, the utility model provides a kind of strengthen supplementary combustion type combined cycle waste heat boiler, it can realize the maximum continuous evaporation capacity of boiler.

[0004] The technical scheme is as follows: a kind of strengthen supplementary combustion type combined cycle waste heat boiler, it includes combustion chamber and horizontal flue, it is characterized in that, supplementary combustion burner nozzle is provided in the combustion chamber, the horizontal flue is sequentially divided into first flue, denitration area, second flue, third flue along the flue gas flow direction, high-pressure evaporator and high-pressure superheater are provided in the first flue, high-pressure economizer, low-pressure superheater and low-pressure evaporator are provided in the second flue, low-pressure economizer is provided in the third flue.

[0005] It is further characterized in that, the high-pressure evaporator includes light pipe high-pressure evaporator and finned tube high-pressure evaporator, the light pipe high-pressure evaporator, high-pressure superheater and finned tube high-pressure evaporator are sequentially provided in the first flue;

[0006] The high-pressure economizer is provided with three groups, the low-pressure superheater is arranged between the first group of high-pressure economizer and the second group of high-pressure economizer, and the low-pressure evaporator is arranged behind the high-pressure economizer;

[0007] The third flue is also provided with desalted water heater and located behind the low-pressure economizer.

[0008] After the utility model is adopted, the supplementary combustion technology of supplementary combustion burner nozzle can ensure that the output of waste heat boiler can reach the required rated value when the output of gas turbine is in 60% to 100% working condition, and the heating surface structure of waste heat boiler is optimized, the supplementary combustion power is increased when the output of gas turbine is 100%, so that the output of boiler exceeds the rated capacity by 10%, and the maximum continuous evaporation capacity of boiler is realized. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 The utility model structural schematic diagram. DETAILED DESCRIPTION

[0010] See Figure 1 As shown in the figure, a reinforced supplementary combustion type combined cycle waste heat boiler, which comprises a combustion chamber 1 and a horizontal flue, a supplementary combustion burner nozzle 2 is arranged in the combustion chamber, the horizontal flue is sequentially divided into a first flue 3, a denitration zone 4, a second flue 5 and a third flue 6 along the flue gas flow direction, a high-pressure evaporator and a high-pressure superheater 7 are arranged in the first flue, the high-pressure evaporator comprises a light tube high-pressure evaporator 8 and a fin tube high-pressure evaporator 9, and the sequence along the flue gas flow direction is one group of light tube high-pressure evaporators 8, three groups of high-pressure superheaters 7 and three groups of fin tube high-pressure evaporators 9, a high-pressure economizer 10, a low-pressure superheater 11 and a low-pressure evaporator 12 are arranged in the second flue 5, the high-pressure economizer 10 is provided with three groups, the low-pressure superheater 11 is arranged between the first group of high-pressure economizers and the second group of high-pressure economizers, and three groups of low-pressure evaporators 12 are arranged behind the high-pressure economizer 10; a low-pressure economizer 13 and three groups of desalted water heaters 14 are sequentially arranged in the third flue.

[0011] Fuel gas is sent into the supplementary combustion burner nozzle 2 after decompression by the burner pry block, the flue gas after combustion and the gas turbine exhaust gas are mixed and then flow to each heat exchange surface at the rear of the combustion chamber 1; the flue gas after supplementary combustion has a high temperature, passes through one group of light tube high-pressure evaporators 8 first, three groups of high-pressure superheaters 7 meet the temperature requirement of high-pressure steam, and three groups of fin tube high-pressure evaporators 9 at the rear meet the evaporation capacity requirement; denitration equipment is arranged in the denitration zone 4 to meet the emission requirement of nitrogen oxides of the unit; the heating surface arrangement in the second flue 5 is set according to the low-pressure main steam temperature requirement; the three groups of desalted water heaters 14 in the third flue 6 can also reduce the flue gas emission temperature of the boiler, improve the boiler efficiency and increase the step-by-step utilization of energy.

Claims

1. A recuperation enhanced combined cycle waste heat boiler comprising a combustion chamber and a horizontal flue, characterized in that, The combustion chamber is provided with a supplementary combustion burner nozzle, and the horizontal flue is sequentially divided into a first flue, a denitration zone, a second flue and a third flue along the flue gas flow direction; the first flue is provided with a high-pressure evaporator and a high-pressure superheater; the second flue is provided with a high-pressure economizer, a low-pressure superheater and a low-pressure evaporator; and the third flue is provided with a low-pressure economizer.

2. A recuperation boiler for a supplementary combustion combined cycle according to claim 1, characterized in that, The high-pressure evaporator comprises a light-pipe high-pressure evaporator and a finned-pipe high-pressure evaporator; and the first flue is sequentially provided with the light-pipe high-pressure evaporator, the high-pressure superheater and the finned-pipe high-pressure evaporator.

3. A recuperation boiler for a supplementary combustion combined cycle according to claim 1, characterized in that, The high-pressure economizer is provided in three groups; the low-pressure superheater is arranged between the first group of high-pressure economizers and the second group of high-pressure economizers; and the low-pressure evaporator is arranged behind the high-pressure economizers.

4. A recuperation boiler for a supplementary combustion combined cycle according to claim 1, characterized in that, The third flue is further provided with a desalted water heater and is located behind the low-pressure economizer.

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