Method for determining acid dew point of boiler flue gas engineering

Abstract

The invention discloses a method for determining the acid dew point of boiler flue gas engineering. The method comprises the following steps of: (1) extending a heat exchange section of a heat exchanger, a detection section of an air speed detector and a sensor part of a flue gas analyzer into a flue; (2) closing a water outlet valve, opening a water supplementing port valve, setting the preset temperature T0 of a temperature control water tank to be above 70 DEG C, and opening the water outlet valve and starting a water pump when the water temperature data displayed on a data acquisition instrument reaches T0; (3) recording the flue gas temperature Tgas, inlet water temperature Tin, outlet water temperature Tout, wall temperature Tw of heat exchanger, volume flow qv and glue gas air speed value vg; (4) calculating the Noshir Nu under different flow Renault numbers Ref when the wall temperature of the heat exchange is Tw; (5) gradually reducing the preset temperature T0, and repeating the steps (3) and (4) to obtain the Noshir Nu under different Renault numbers Ref at different wall temperatures Tw of the heat exchange; and (6) observing the Noshir number under different wall temperatures to determine the temperature before Noshir number mutation to be the acid dew point of the engineering.

Description

technical field [0001] The invention relates to the field of energy and power engineering, in particular to a method for determining the sudden critical temperature (engineering acid dew point) of heat exchange performance of a heat exchanger in the utilization of waste heat from flue gas at the tail of a boiler. Background technique [0002] Among the various losses of the boiler, the exhaust gas loss is the largest one. The test shows that for every 10-20°C increase in the exhaust gas temperature, the thermal efficiency of the boiler will decrease by about 0.6%-1%, and the corresponding more coal consumption will be 2-3g / KWh Therefore, it is of great practical significance for energy saving and emission reduction to make full use of the waste heat of boiler flue gas and reduce the exhaust gas temperature as much as possible. [0003] However, with the use of the waste heat of the flue gas at the tail of the boiler flue, the exhaust gas temperature will become lower. As th...

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Problems solved by technology

[0009] Based on the above reasons, due to the large ash content in the boiler flue gas, it is difficult to obtain the dew point accurately by the traditional dew point test method, and the temperature in the boiler flue is high and the sealing is strong, so it is difficult to directly observe, so there is no good determination of the heat exchanger. The method and device for sudden change critical temperature (engineering acid dew point) of heat exchange performance, engineering design is still mainly based on experience

This is not conducive to the full use of waste heat flue gas, and may bring safety hazards

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