Liquid phase intermediate medium heat exchanging type heat exchanger

Abstract

The invention relates to a liquid-phase intermediate medium heat-exchanging type heat exchanger used in boilers, chemical industry and industrial furnaces, comprising a circulating pipeline, a medium recycle pump with a frequency converter which is arranged on the circulating pipeline, a medium heating section which is arranged on the circulating pipeline in a flue gas channel, and a medium heat output section arranged on the circulating pipeline. The temperature rises when a heat transmission medium absorbs waste heat of flue gas on the medium heating section without phase transition, while the temperature reduces when heat is released to a heated medium through the medium heat output section, so that the liquid-phase intermediate medium heat-exchanging type heat exchanger has the characteristics of guaranteeing that the lowest wall temperature of a heating surface is higher than the flue gas acid dew point while greatly reducing the exhaust gas temperature of a boiler so as to avoid the occurrence of low temperature corrosion; an automatic control device can be used to automatically control and adjust the lowest wall temperature through adjusting flow rate of the recycle pump to adapt to the working condition of the boiler and the variance in fuel; moreover, the liquid-phase intermediate medium heat-exchanging type heat exchanger has the characteristics of flexibility, space saving, etc. in the arrangement of equipment; the heat exchanger can replace a rotating air preheater, a tube type air preheater, a heat pipe air preheater and a compound phase-changing heat exchanger.

Description

Technical field: [0001] The invention relates to a liquid phase intermediate medium heat exchange type heat exchanger used in boilers, chemical industry and industrial kilns. Background technique: [0002] It is well known that due to the SO in boiler flue gas 3 The exit flue gas temperature of the tail heating surface air preheater is limited. If the exhaust gas temperature is too low, it will lead to serious dew condensation corrosion and ash blocking because the minimum wall temperature of the heating surface is lower than the acid dew point of the flue gas. Therefore, the design exhaust temperature of the boiler should not be too low. The design exhaust temperature of the tubular air preheater is usually 140°C to 160°C or higher; the design exhaust temperature of the rotary air preheater is usually 130°C to 140°C. ℃. Even so, the corrosion and dust blocking phenomenon of the heating surface are still unavoidable. The minimum wall temperature of the rotary air preheat...

AI Technical Summary

Problems solved by technology

However, due to structural reasons, the heating surface of the phase change section must be arranged on the horizontal flue, which limits the range of space that can be arranged.

At the same time, in order to remove the dry dust accumulation on the heating surface of the phase change section, a special dust removal device must be configured

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