A high bed temperature circulating fluidized bed boiler with steam parameters of 700°C and above

Abstract

The invention discloses a circulating fluidized bed boiler with a high bed temperature and with a steam parameter of 700 DEG C and above. 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 rear flue. The contraction ratio of the lower part of the combustion chamber along the depth direction is 0.22-0.48. A flue gas damper is arranged in the rear flue. The rear flue contains at least two parallel flues. A low-temperature superheater is arranged in one parallel flue. A low-temperature reheater is arranged in the other parallel flue. A medium-temperature superheater is arranged in one external heat exchanger. A high-temperature reheater is arranged in one external heat exchanger. A high-temperature superheater is arranged in the combustion chamber. The boiler can effectively raise the heat-transfer intensity inside the combustion chamber, the bed temperature can reach 950 DEG C and above, the steam parameter can reach 700 DEG C and above, 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 used for ultra-supercritical power generation with steam parameters of 700°C and above. 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] Improving steam parameters is one of the most effective ways to obtain higher power generation efficiency. In fact, after the 600°C grade ultra-supercritical power generation technology matured, developed cou...

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Problems solved by technology

Therefore, in order to consider the heat-carrying capacity of the tubes on the heating surface, and the steam flow rate should not be too low, it is difficult to balance the two; the above all limit the implementation of the steam parameters of 700°C and above in the circulating fluidized bed combustion technology, so that the circulating flow It is difficult to realize the further improvement of the efficiency of the chemical bed boiler unit

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