Method for recovering waste heat from coke oven raw gas

Abstract

The invention relates to a method for recovering waste heat from a coke oven raw gas. The method utilizes water as a heat exchange medium, water exchanges heat with the raw gas having a temperature of about 650-750DEG C in a riser heat exchanger, the temperature of the raw gas subjected to the heat exchange decreases to 480-550DEG C, the heat exchange medium forms a vapor-water mixture after heating, and enters a vapor bag, and the vapor-water mixture is separated to form high temperature water and saturated vapor by a vapor-water separator in the vapor bag; the raw gas discharged from the riser heat exchanger undergoes heat exchange in a bridge tube heat exchanger, the temperature of the raw gas subjected to the heat exchange decreases to 280-350DEG C, and the high temperature water obtained after the separation of the vapor-water separator undergoes heat exchange by the bridge tube heat exchanger, enters the vapor bag and generates saturated vapor, wherein the outer wall of the heat exchanger is cleaned through high-pressure ammonia water intermittent spray or water vapor intermittent blow in the bridge tube; and finally the temperature of the raw gas is reduced to 80-85DEG C by adopting ammonia water, and then the raw gas enters a gas collection tube. The method furthest recovers the waste heat of the raw gas and guarantees the continuous normal work of the heat exchangers under a complex condition.

Description

technical field [0001] The invention belongs to the technical field of high-efficiency recovery and utilization of waste heat resources in the coking process, and in particular relates to a method for recovering waste heat from raw coke oven gas. Background technique [0002] The State Council pointed out in the "Twelfth Five-Year Plan for Energy Conservation and Emission Reduction" that the waste heat and pressure utilization project is one of the top ten key projects for energy conservation and emission reduction during the "Twelfth Five-Year Plan" period. The waste heat generated in the coking production process is large and has high energy value, which has great recycling value and is an important aspect of energy-saving and potential tapping in the coking industry. [0003] The 650℃~750℃ high-temperature raw coal gas generated from the carbonization chamber of the coke oven escapes through the riser pipe. In order to cool the high-temperature raw gas, the traditional m...

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Problems solved by technology

[0009] Aiming at the deficiencies in the prior art, the present invention proposes a method for recovering waste heat from coke oven raw gas. The purpose of this method is to solve the waste of high-quality heat and cooling water consumption in the previous method of cooling raw gas with ammonia water. Large volume and low heat recovery efficiency of the riser waste heat recovery device. At the same time, high-pressure ammonia water intermittent spraying or steam intermittent purging is used to solve the problem of heat exchange efficiency reduction caused by tar condensation on the outer wall of the inner tube of the bridge tube heat exchanger. It can not only recover the sensible heat and latent heat of raw gas to the greatest extent, but also ensure the continuous and normal operation of the heat exchange device under such complex working conditions, and use the recovered waste heat to generate steam for chemical production as a heat source or for power generation. In order to achieve the purpose of waste heat recovery and utilization of raw coal gas

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