Spraying-absorbing-type method and spraying-absorbing-type device for waste heat recovery of fuel-gas flue gas

Abstract

The invention discloses a spraying-absorbing-type method and a spraying-absorbing-type device for waste heat recovery of fuel-gas flue gas. Fuel gas drives a generator to combust, released energy is taken as a high-temperate heat source for a absorption refrigerating machine, flue gas generated after combustion is mixed with boiler flue gas, and the mixed flue gas enters n-level spraying elements, directly contacts with spray water in the spraying elements to be evaporated and cooled, and are then exhausted from a flue-gas outlet; automatic-circulation water enters a first-level spraying unit from a spraying-element circular-water inlet to be sprayed, outlet water of each level spraying unit is delivered to a next spraying element under the action of a spraying water pump to be sprayed, outlet water of the nth-level spraying element is pumped into an evaporator from a chilled-water inlet of the evaporator by a circulating water pump to be cooled, and cooled chilled water is delivered to the first-level spraying unit to complete automatic circulation of the spray water. By the method, energy can be effectively saved, heating capacity can be effectively improved, SO2 (sulfur dioxide) and NOx (nitrogen oxides) in the flue gas are removed, and pollution of the flue gas to environment is reduced.

Description

technical field [0001] The invention belongs to the field of energy, and in particular relates to a method and a device for recovering waste heat from a novel spray-absorption gas flue gas. Background technique [0002] At present, gas-fired equipment has been widely used in my country. The direct combustion of natural gas will produce a large amount of high-temperature flue gas. The flue gas not only carries a large amount of waste heat, but also contains NO x and SO 2 and other harmful gases, the recovery and utilization of waste heat of flue gas, and the removal of harmful pollutants in flue gas have become the key to energy saving and emission reduction of gas combustion equipment. The flue gas after natural gas combustion not only has a high temperature, but also contains a large amount of water vapor, in which the condensation heat of water vapor accounts for more than 70% of the waste heat of the flue gas. At present, there are two main types of flue gas waste heat ...

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Problems solved by technology

[0004] There are also projects that use the flue gas heat recovery technology of absorption cycle and flue gas-water heat exchange in the same project, but because each part of the device occupies a large area, and the distribution of the device is not compact enough, the smoke pipe and water pipe are added. The laying cost and pipeline resistance make it an inevitable development direction to develop an integrated device that can reasonably combine the two technologies

Moreover, the above-mentioned flue gas waste heat recovery method or device generally only considers the recovery of sensible heat and latent heat in the flue gas, and has no effect on the removal of NO contained in the flue gas. X and SO 2 The consideration of harmful gases such as NO x It is the main source of PM2.5 in the atmosphere. Therefore, while recovering the waste heat of the flue gas, it can also remove the NO in the exhaust gas x and SO 2 also become very necessary

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