System and method for high-temperature biomass gas cooling and waste heat utilization

Abstract

The invention discloses a system and method for high-temperature biomass gas cooling and waste heat utilization. A main flue formed by a coal-fired boiler, an air preheater, a dust collector, an induced draft fan and a desulfurization island which are connected in series is included, and a flue gas recirculation pipe, a heat conducting medium-flue gas heat exchanger, a gas-heat conducting medium heat exchanger and a spray drying tower are further included; the spray drying tower is connected to the part, in front of the dust collector, of the main flue, the flue gas recirculation pipe is connected to the part, behind the dust collector, of the main flue, and the main flue communicates with the heat conducting medium-flue gas heat exchanger through the flue gas recirculation pipe; and fluegas of the heat conducting medium-flue gas heat exchanger communicates with the spray drying tower, a heat conducting medium of the heat conducting medium-flue gas heat exchanger is in communication with the gas-heat conducting medium heat exchanger, and gas of the gas-heat conducting medium heat exchanger communicates with the coal-fired boiler. By means of the system and method, sensible heat ofwaste biomass gas is utilized to remove harmful substances in desulfurization waste water, energy saving and environment protection can be achieved, and by-product salt crystals are high in purity and high in added value.

Description

technical field [0001] The invention belongs to the field of coal-fired coupled biomass power generation, and in particular relates to a system and method for cooling high-temperature biomass gas and utilizing waste heat. Background technique [0002] Coal-fired coupled biomass coupled power generation technology can solve social governance problems such as direct burning of straw in the field, overcome the shortcomings of high pollutant emission levels in the energy utilization of biomass resources, and promote the low-carbon and clean development of the power industry, especially coal power. Among them, the coupling of biomass gasification is an important way of coupled power generation. [0003] Biomass circulating fluidized bed gasification is through biomass oxidative combustion, reduction and thermal decomposition reactions in the gasifier, including the combustion of some raw materials with oxygen in the air to provide the energy required for reduction and thermal dec...

AI Technical Summary

Problems solved by technology

However, the air preheater is generally located at a height of more than 20 meters. If the high-temperature flue gas is drawn from the front of the air preheater to zero meters, the flue length will be longer and there will be more elbows. After passing through the dust collector, it is easy to cause dust accumulation at the elbow; if the high-temperature flue gas is drawn from the front of the air preheater to the independent evaporation tower built on the boiler steel frame in order to reduce the length of the flue, it will cause new damage to the boiler steel frame. Adding a large load, especially for the renovation project, generally requires reinforcement to increase the large load on the original boiler steel frame, and the reinforcement generally requires a large increase in cost

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