Controllable exhaust gas temperature sub-control phase change air preheating system and preheating method

Abstract

The invention relates to a controllable exhaust gas temperature sub-control phase change air preheating system and a preheating method. The preheating system comprises an air preheater (4) and an air channel (5) communicated with the air preheater (4) and a fume channel (7), wherein the front of the air preheater (4) arranged on the air channel (5) is provided with a low-temperature heat release device (18) along an air flow direction; the front and rear of the air preheater (4) arranged on the fume channel (7) are respectively provided with a high temperature heat absorption device (6) and a low temperature heat absorption device (1) along a fume flowing direction; the low-temperature heat release device (18) and a main steam pipe (15) connected with a steam connecting box are respectively communicated with the high temperature heat absorption device (6) and the low temperature heat absorption device (1); and a condensed water main pipe (16) of a condensed water connecting box of the low-temperature heat release device (18) is respectively communicated with the high temperature heat absorption device (6) and the low temperature heat absorption device (1) through branch pipes. According to the change of coal and unit load in the invention, and the waste heat recovery volume and fume exhaust gas temperature are adjusted.

Description

technical field [0001] The invention relates to the field of waste heat recovery and utilization of boiler flue gas and production process tail gas. Specifically, the invention relates to a separate-controlled phase-change air preheating system and a preheating method with controllable exhaust gas temperature. Background technique [0002] Due to changes in coal types, equipment conditions, seasons, and unit loads, as well as design errors, the exhaust gas temperature after the air preheater in actual operation often deviates from the design value under the design conditions. Due to the traditional air preheater All adopt fixed design parameters according to the design working conditions, and the heat exchange capacity of the heat exchange equipment cannot be adjusted. Therefore, either because the exhaust gas temperature of the boiler is too high, the loss of energy consumption is very large, or the low temperature corrosion of the air preheater is caused by the exhaust gas...

AI Technical Summary

Problems solved by technology

In addition, since the temperature of the flue gas exchanging heat with the high-temperature heat-absorbing device is often higher than the critical parameter of water, the phase change parameters are not easy to control and stabilize. Extremely high, increasing equipment cost and reducing equipment safety

Images