Circulating fluidized bed boiler with second reheaters

Abstract

The invention discloses a circulating fluidized bed boiler with second reheaters. The boiler comprises an air compartment, an air distributor, a combustion chamber, a primary air system, a second air system, a horizontal flue, a plurality of cyclone separators, a plurality of external heat exchangers and a back-end flue. The contraction ratio of the lower part of the combustion chamber is 0.2-0.49. A flue gas damper is arranged in the back-end flue. The back-end flue contains at least two parallel flues. A low-temperature superheater is arranged in one parallel flue. A primary low-temperature reheater is arranged in the other parallel flue. A medium-temperature superheater is arranged in at least one external heat exchanger. A primary high-temperature reheater is arranged in at least one external heat exchanger. A second low-temperature reheater and a second high-temperature reheater are arranged in at least one external heat exchanger. A high-temperature superheater is arranged at the upper part of the combustion chamber. The boiler can effectively raise the heat-transfer intensity inside the boiler, and cooperates with optimized heating surface arrangement modes to achieve effective combination of second reheaters and a circulating fluidized bed, and therefore the aims of raising power generating efficiency of coal power units and reducing pollutant discharge are achieved, and long and high-efficient running of the device can be guaranteed.

Description

technical field [0001] The invention relates to a circulating fluidized bed boiler, in particular to a circulating fluidized bed boiler with secondary reheating. Background technique [0002] my country has become the world's largest energy producer and consumer. The proportion of coal in the energy structure has been around 70% in the past ten years, and it is expected to continue until the middle of this century. However, in my country's coal resources, low-quality coal with high sulfur content and high ash content accounts for a relatively high proportion. Therefore, improving the power generation efficiency of units and reducing pollutant emissions are the central tasks of the power industry. [0003] Circulating fluidized bed combustion technology is the only high-efficiency and clean combustion utilization technology of low-grade fuel that has been developed in the past 30 years and has achieved commercialization and large-scale utilization at the present stage. Tw...

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Problems solved by technology

[0005] The purpose of the present invention is to address the above-mentioned shortcomings in the prior art and overcome the difficulties in combining the above-mentioned secondary reheating with the circulating fluidized bed boiler, and provide a circulating fluidized bed boiler with secondary reheating, which is not significantly In the case of increasing fuel, it can effectively improve the heat transfer intensity and heat utilization rate in the furnace, so as to realize the effective combination of secondary reheating and circulating fluidized bed boiler, and achieve the goal of further improving the power generation efficiency of coal-fired power units and the coexistence of low pollutant emissions , and ensure the long-term efficient operation of the equipment

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