CN216717021U - Raw coke oven gas waste heat and dry quenching coke waste heat combined recycling system - Google Patents

Abstract

The utility model discloses a raw coke oven gas waste heat and dry quenching coke waste heat combined recycling system, wherein a water feeding pump is connected with a first steam pocket inlet, steam heated by an ascending pipe is connected with the first steam pocket inlet, a first steam pocket water outlet is heated in the ascending pipe by a first circulating water pump, the first steam pocket steam outlet is connected with a steam turbine, and the steam acts in the steam turbine. In the coking process of the coke oven, a great amount of raw gas escapes from the coking chamber, the high-temperature raw gas at 750 ℃ enters the riser evaporator of the coke oven, the temperature is reduced to about 500 ℃ after heat exchange, and the application of the riser waste heat recovery system plays a vital role in improving the operation environment at the top of the coke oven.

Description

A combined recovery and utilization system of waste heat from waste gas and coke dry quenching

technical field

The utility model belongs to the field of waste heat recovery equipment, in particular to a combined recovery and utilization system of waste heat from waste gas and coke dry quenching.

Background technique

The coking chemical industry is an important part of my country's national economy. The production process of coke is: heating and dry distillation with coal in a coke oven under the condition of isolating air, and then drying, pyrolysis, melting, bonding, solidification, shrinkage and other processes to make Coke, a large amount of waste gas is produced in the process. In the production energy consumption of coke ovens, the sensible heat brought out by high-temperature red coke accounts for about 37%, the sensible heat brought out by high-temperature waste gas accounts for about 36%, the sensible heat of coke oven flue gas accounts for about 17%, and the heat dissipation of coke ovens accounts for about 17%. about 10%. Among them, the sensible heat of red coke can be better recovered by CDQ technology. CDQ is a technology used to recover the sensible heat of red coke in the coking process. CDQ technology can recover more than 80% of the sensible heat of red coke. The temperature of the coke oven waste gas is 650 ℃ ~ 800 ℃, and this part of the heat belongs to the medium temperature waste heat. Since the early 1980s, domestic attempts to recover the sensible heat from coking waste gas have been attempted, but so far no mature, reliable and efficient recycling technology has been formed, and the waste heat resources of coke oven waste gas have not been effectively recycled, causing a large Energy waste.

Utility model content

The purpose of this utility model is to provide a combined recovery and utilization system of waste heat from waste gas and coke dry quenching. The outlet of the water drum is heated in the riser pipe through the first circulating water pump, and the steam outlet of the first steam drum is connected to the steam turbine, and the steam goes to the steam turbine to do work.

The inert gas in the CDQ takes away the high temperature heat of the coke. After removing excess impurities through the first electrostatic precipitator, it enters the waste heat boiler to heat the feed water in the waste heat boiler, and then returns to the CDQ through the second electrostatic precipitator. recycle.

The feed water pump is connected to the waste heat boiler, and the feed water first goes to the economizer in the waste heat boiler for heating, and then goes to the second steam drum through the pipeline.

The water from the second steam drum passes through the second circulating water pump, enters the finned evaporator in the waste heat boiler to be heated, and then returns to the second steam drum through the pipeline.

The steam in the second steam drum is returned to the superheater in the waste heat boiler and becomes superheated steam, which is mixed with the steam from the first steam drum to do work in the steam turbine.

The beneficial effects of the present utility model are:

1. During the coking process of the coke oven, a large amount of waste gas escapes from the carbonization chamber, and the high temperature waste gas at 750°C enters the coke oven riser evaporator. After heat exchange, the temperature is reduced to about 500°C. The application of the waste heat recovery system in the riser It plays a vital role in improving the working environment of the furnace top. According to the measurement, the temperature of the outer wall of the old riser tube is above 200℃, and the temperature of the outer wall of the new tube gradually decreases from about 100℃ at the bottom of the lower section of the riser to the upper section. When the temperature is 40℃～50℃ on the top, the temperature of the working environment on the furnace top can be reduced by about 20℃, which improves the working environment on the furnace top.

2. CDQ can recover 80% of the heat of the red coke, the coke enters the CDQ furnace, the temperature of the red coke is 950-1050℃, and it exchanges heat with the countercurrent circulating inert gas, the coke is cooled to below 200℃, and the circulating inert gas changes from 130 When the temperature rises to above 900-960°C, the heat of the coke is recovered and used to heat the feed water in the waste heat boiler, which turns into superheated steam to do work in the steam turbine.

3. The heat from the red coke and the waste gas together account for 73% of the coking heat. The high-temperature waste heat of the red coke and the medium-temperature waste heat of the waste gas are jointly recovered, which not only realizes energy saving and emission reduction, but also further improves the energy utilization rate. It not only contributes to environmental protection but also creates considerable economic benefits, which is in line with the national energy-saving policy.

Description of drawings

Figure 1 shows a combined recovery and utilization system of waste heat from waste gas and coke CDQ.

In the figure: 1- feed water pump; 2- first steam drum; 3- first circulating water pump; 4- riser pipe; 5- steam turbine; 6- CDQ; 7- first electrostatic precipitator; 8- waste heat boiler; 9-Second circulating water pump; 10-Second steam drum; 11-Superheater; 12-Fin evaporator; 13-Economizer; 14-Second electrostatic precipitator.

Detailed ways

The utility model provides a combined recovery and utilization system of waste heat from waste gas and coke dry quenching. The working principle of the system is further described below with reference to the accompanying drawings and specific embodiments.

Figure 1 shows a schematic diagram of a combined recovery and utilization system for waste heat from waste gas and CDQ. The feed pump 1 of the system is connected to the inlet of the first steam drum 2, and the steam heated by the riser 4 is connected to the first steam drum 2. The inlets are connected, the water outlet of the first steam drum 2 is heated in the riser 4 through the first circulating water pump 3, and the steam outlet of the first steam drum 2 is connected to the steam turbine 5, and the steam goes to the steam turbine 5 to do work.

The inert gas in the CDQ 6 takes away the high temperature heat of the coke, and after removing excess impurities through the first electrostatic precipitator 7, it enters the waste heat boiler 8 to heat the feed water in the waste heat boiler 8, and then passes through the second electrostatic precipitator 14. It is recycled to the CDQ6.

The feed water pump 1 is connected to the waste heat boiler 8, and the feed water first goes to the economizer 13 in the waste heat boiler 8 to be heated, and then goes to the second steam drum 10 through the pipeline.

The water from the second steam drum 10 passes through the second circulating water pump 9, enters the finned evaporator 12 in the waste heat boiler 8 to be heated, and then returns to the second steam drum 10 through the pipeline.

The steam in the second steam drum 10 returns to the superheater 11 in the waste heat boiler 8 to become superheated steam, which is mixed with the steam from the first steam drum 2 and goes to the steam turbine 5 to do work.

Its working process is:

The waste gas is heated from the coke oven carbonization chamber through the waste gas waste heat recovery device of the rising pipe 4, and the temperature of the flue gas drops to above 450 °C. The steam-water separation is performed, and the steam is output from the steam drum to the steam turbine 5 to do work.

The temperature of the red coke pushed out from the carbonization chamber into the CDQ furnace 6 is 950-1050°C. After the red coke loaded into the CDQ furnace 6 is stored for a period of time in the pre-storage section, the red-hot coke flows downward as the coke removal proceeds. Entering the cooling section, the low-temperature circulating gas at 130°C from the bottom of the CDQ furnace 6 flows upward in the cooling section, and the two conduct countercurrent heat exchange, and the coke is cooled to below 200°C and discharged from the bottom of the CDQ furnace 6. The circulating gas passes through the first The electrostatic precipitator 7 exchanges heat in the waste heat boiler 8 to heat the feed water. The feed water from the feed pump 1 is first heated by the economizer 13 in the waste heat boiler 8 and enters the second steam drum 10. The water from the second steam drum 10, After passing through the second circulating water pump 9, the finned evaporator 12 entering the waste heat boiler 8 is heated, and then returns to the second steam drum 10 through the pipeline, and the steam in the second steam drum 10 returns to the superheated steam in the waste heat boiler 8 again. In the boiler 11, it becomes superheated steam, which is mixed with the steam coming out of the first steam drum 2, and goes to the steam turbine 5 to do work.

Claims (3)

1. A raw gas waste heat and dry quenching waste heat combined recycling system is characterized in that a water feed pump (1) is connected with an inlet of a first steam pocket (2), steam heated by an ascending pipe (4) is connected with an inlet of the first steam pocket (2), a water outlet of the first steam pocket (2) is heated in the ascending pipe (4) through a first circulating water pump (3), a steam turbine (5) is connected with a steam outlet of the first steam pocket (2), the steam works in the steam turbine (5), inert gas in a dry quenching furnace (6) takes away high-temperature heat of coke, the inert gas in the first electric precipitator (7) removes redundant impurities and then enters a waste heat boiler (8) to heat feed water in the waste heat boiler (8), the feed water returns to the dry quenching furnace (6) through a second electric precipitator (14) to be recycled, the water feed pump (1) is connected with the waste heat boiler (8), and the feed water firstly enters a coal economizer (13) in the waste heat boiler (8) to be heated, through a conduit to a second drum (10).

2. The system for jointly recycling the waste heat of the raw coke oven gas and the waste heat of the dry quenching as claimed in claim 1, wherein the water from the second steam drum (10) passes through the second circulating water pump (9), enters the fin evaporator (12) of the waste heat boiler (8) to be heated, and then returns to the second steam drum (10) through a pipeline.

3. The system for jointly recycling the waste heat of the raw coke oven gas and the waste heat of the dry quenching coke as claimed in claim 1, wherein the steam in the second steam drum (10) returns to the superheater (11) in the waste heat boiler (8) again to become superheated steam, and the superheated steam is mixed with the steam coming out of the first steam drum (2) and is sent to the steam turbine (5) to do work.

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