Heat pipe-cast iron pipe combined type air preheater and waste heat recovery method for heating furnace

Abstract

The invention discloses a heat pipe-cast iron pipe combined type air preheater which comprises a heat pipe air preheater, an air outlet and a flue gas inlet, wherein the air outlet is formed in the upper end on one side of the heat pipe air preheater, and the flue gas inlet is formed in the lower end on one side of the heat pipe air preheater; the lower end on the other side of the heat pipe air preheater is connected with a pipe-cast iron pipe air preheater, and the other side of the pipe-cast iron pipe air preheater is connected with a flue gas outlet; the bottom end of the pipe-cast iron pipe air preheater is connected with an air inlet, and an air channel is connected between the top end of the pipe-cast iron pipe air preheater and the upper end on the other side of the heat pipe air preheater. The invention further discloses a waste heat recovery method for a heating furnace. The method comprises the following steps: high-temperature flue gas enters the air preheater; after the high-temperature flue gas exchanges heat with air, the temperature is lowered, and the flue gas leaves the air preheater; normal-temperature air enters the air preheater; after the normal-temperature air exchanges heat with the flue gas, the temperature is raised, and the air leaves the air preheater. The heat pipe-cast iron pipe combined type air preheater has the advantages of being simple in structure, low in cost and wide in application to fuel, and the problem of dew point corrosion of the air preheater is solved.

Description

technical field [0001] The invention relates to a heat exchange system, in particular to a heat pipe-cast iron pipe combined air preheater suitable for recovery of waste heat from a heating furnace and a method for recovering waste heat from a heating furnace. Background technique [0002] At present, the waste heat recovery system of heating furnaces in chemical, petrochemical and coal chemical industries generally uses air preheaters to recover the waste heat in flue gas, so as to improve the thermal efficiency of heating furnaces and reduce operating costs. In theory, in order to improve the thermal efficiency of the heating furnace, the exhaust gas temperature of the heating furnace should be reduced as much as possible. In actual application, due to the influence of sulfur and water content in flue gas components, when the flue gas exhaust temperature drops to a certain level, different degrees of dew point corrosion will inevitably occur at the end of the low-temperatu...

AI Technical Summary

Problems solved by technology

In actual application, due to the influence of sulfur and water content in flue gas components, when the flue gas exhaust temperature drops to a certain level, different degrees of dew point corrosion will inevitably occur at the end of the low-temperature section of the air preheater. Shortened air preheater service life

Air preheaters in the prior art either use one type of heat exchange element, such as spoiler air preheater, heat pipe air preheater, or use combined heat exchange elements, such as spoiler + heat pipe air Preheater, etc. All of the above air preheaters have the aforementioned dew point corrosion problem, which affects the service life of the air preheater

Images