CN-116242149-B - Gradient utilization system for waste heat of sinter cooling waste gas and use method

Abstract

The invention relates to a sintering ore cooling waste gas waste heat cascade utilization system and a use method thereof, wherein the system comprises an annular cooler, a sealing upper cover, an air box and a waste gas circulation system, the waste gas circulation system comprises a waste heat boiler, a regulating valve and a bleeding valve, all accident bleeding valves are in a closed state in a normal production state, waste gas discharged from the first section of the upper cover and the second section of the upper cover enters the waste heat boiler, and after heat exchange, the waste gas is sent into a return air second section of the air box and a return air third section of the air box by a heat returning fan I; when the inlet air temperature of the waste heat boiler is higher, the inlet air temperature of the waste heat boiler is regulated through a regulating valve and an accident diffusing valve, waste gas of the third section of the upper cover is sent to the material surface of the sintering machine or the first section of return air bellows, waste gas of the fourth section of the upper cover is sent to the first section of return air bellows or is purified by a dust removal system and then is discharged, and waste gas of the fifth section of the upper cover is sent to the fourth section of return air bellows by a backheating fan IV. The method has the advantages of effectively improving the utilization rate and the operation stability of the waste heat boiler, increasing the self-circulation proportion of waste gas and realizing zero emission of waste gas of the circular cooler.

Inventors

• ZHENG SUIXU
• ZHOU ZHIAN
• YOU GAO
• LUO ZONGWEI
• ZHANG ZHIGANG
• XIA KEBIN
• ZHANG ZHONGZHEN
• HUANG YALEI
• LI HUIMIN

Assignees

• 中冶北方（大连）工程技术有限公司

Dates

Publication Date

20260508

Application Date

20211207

Claims (2)

1. 1. Sinter cooling waste gas waste heat cascade utilization system, including ring cooler (1), set up at the sealed upper cover on ring cooler upper portion, set up bellows and exhaust gas circulation system in ring cooler lower part, sealed upper cover be upper cover one section (111), upper cover two sections (112), upper cover three sections (113), upper cover four sections (114) and upper cover five sections (115) in proper order along the material advancing direction, bellows be return air one section bellows (121), return air two sections bellows (122), return air three sections bellows (123), return air four sections bellows (124) and normal atmospheric temperature cooling bellows (125) in proper order, exhaust gas circulation system include exhaust-heat boiler (2), backheat fan, three-way pipeline and governing valve, its characterized in that: The upper cover first section (111) is connected with a waste heat boiler (2) through a waste gas pipeline A and a regulating valve A (21), the upper cover second section is connected with the waste heat boiler (2) through a waste gas pipeline B and a regulating valve B (22), the waste heat boiler (2) is connected with the inlet of a regenerative fan I (3), the outlet of the regenerative fan I (3) is respectively connected with a return air second section air box (122) and a return air third section air box (123) through a regulating valve C (31) and a regulating valve D (32), An accident diffusing valve A (131) is arranged on the exhaust pipeline A of the first section of the upper cover, an accident diffusing valve B (132) is arranged on the exhaust pipeline B of the second section of the upper cover, an accident diffusing valve C (133) is arranged on the exhaust pipeline D of the fourth section of the upper cover, and an accident diffusing valve D (134) is arranged on the exhaust pipeline E of the fifth section of the upper cover; The upper cover three-section (113) is connected with the inlet of a regenerative fan II (4) through an exhaust gas pipeline C, the regenerative fan II (4) is conveyed to the material surface of the sintering machine through a pipeline for hot air sintering, the upper cover four-section (114) is connected with the inlet of a regenerative fan III (5) through an exhaust gas pipeline D, a regulating valve E (52) and a three-way pipeline I (51), or the upper cover three-section (113) is connected with the inlet of the regenerative fan III (5) through the exhaust gas pipeline C, the regulating valve E (52) and the three-way pipeline I (51), the outlet of the regenerative fan III (5) is connected with a first-section wind box (121), the upper cover four-section (114) is connected with the inlet of a dust removal system (8) through the exhaust gas pipeline D, The outlet of the backheating fan III (5) is connected with a section of return air bellows (121), the five sections (115) of the upper cover are connected with the inlet of the backheating fan IV (6) through an exhaust gas pipeline E, a regulating valve F (62) and a three-way pipeline II (61), the three-way pipeline I (51) and the three-way pipeline II (61) are respectively communicated with the atmosphere through a regulating valve G (53) and a regulating valve H (63), the outlet of the backheating fan IV (6) is connected with a four-section return air bellows (124) through a pipeline, and the normal-temperature cooling bellows (125) is connected with the outlet of the normal-temperature cooling fan (7).
2. 2. The method for using the sintering ore cooling waste gas waste heat cascade utilization system is characterized in that the sintering ore cooling waste gas waste heat cascade utilization system is adopted in the method for using the sintering ore cooling waste gas waste heat cascade utilization system according to claim 1, 1) In a normal production state, all accident bleeding valves are in a closed state, the temperature of waste gas discharged from a first section (111) of an upper cover of the annular cooler is 400 ℃, the temperature of waste gas discharged from a second section (112) of the upper cover of the annular cooler is 300 ℃, two waste gases enter a waste heat boiler (2) through a waste gas pipeline A and a waste gas pipeline B respectively, the two waste gases are subjected to heat exchange by the waste heat boiler (2) and are mixed to be used as cooling air, and the cooling air is sent into a second return air section air box (122) and a third return air section air box (123) through a backheating fan I (3); 2) When the inlet air temperature of the waste heat boiler (2) is higher, the regulating valve A (21) or the regulating valve B (22) is opened, if the regulating valve A (21) or the regulating valve B (22) is fully opened, the inlet air temperature of the waste heat boiler (2) is still higher, the corresponding accident diffusion valve A (131) or the accident diffusion valve B (132) is opened, and a certain amount of ambient air is sucked to regulate the inlet air temperature of the waste heat boiler (2); 3) The waste gas with the temperature of 200-250 ℃ in the three sections (113) of the upper cover is sent to the material surface of the sintering machine through a regenerative fan II (4) for hot air sintering; When the temperature of the waste gas of the upper cover four sections (114) is higher than 150 ℃, the opening of a regulating valve G (53) at the upstream of a three-way pipeline I (51) is regulated to control the proportion of the waste gas from the upper cover four sections (114) and the ambient air, thereby achieving the purpose of controlling the outlet air temperature of the regenerative fan III (5), Or the waste gas with the temperature of 200-250 ℃ in the upper cover three sections (113) is sent into a return air one-section air box (121) by a regenerative fan III (5) to serve as cooling air, when the temperature of the waste gas in the upper cover three sections (113) is higher than 200 ℃, the opening of a regulating valve G (53) at the upstream of a three-way pipeline I (51) is regulated to control the proportion of the waste gas from the upper cover three sections (113) to ambient air, so that the purpose of controlling the outlet air temperature of the regenerative fan III (5) is achieved; Waste gas with the temperature of 150-180 ℃ in four sections (114) of the upper cover is purified by a dust removal system (8) and then discharged; 4) When the temperature of the waste gas of the upper cover five sections (115) is higher than 100 ℃, the proportion of the waste gas from the upper cover five sections (115) to the ambient air is controlled by adjusting the opening of a regulating valve H (63) at the upstream of a three-way pipeline II (61) so as to achieve the purpose of controlling the outlet air temperature of the regenerative fan IV (6).

Description

Gradient utilization system for waste heat of sinter cooling waste gas and use method Technical Field The invention belongs to the technical field of waste gas waste heat recycling systems of circular coolers, and particularly relates to a sintering ore cooling waste gas waste heat cascade utilization system. Background Sintering is one of the most serious procedures in iron and steel enterprises, and in recent years, the high-speed development of terminal treatment technology ensures that particulate matters, sulfur dioxide and nitrogen oxides discharged by a sintering plant are treated to a certain extent, but the problem of unorganized discharge of dust-containing hot waste gas still exists in a cooling link of the sintering ore. At present, some sintering plants adopt novel blast ring coolers (ring coolers for short) for cooling hot sinter, so that the air leakage rate of cooling equipment is greatly reduced, pollution caused by dust carried by air leakage is basically avoided, and the post environment is obviously improved. But except the cyclic utilization of the hot waste gas at the front part of the annular cooler after boiler heat exchange, the rest of the hot waste gas is diffused into the surrounding environment in an unorganized emission mode, the waste heat of the waste gas is not utilized, the carried particulate matters are not treated, part of enterprises collect the dust-containing waste gas at the middle and rear sections of the annular cooler, and the dust-containing waste gas is purified by a high-efficiency dust remover and then discharged after reaching the standard, so that the disposable investment and the operation cost of an environment dust removal system are obviously increased. In order to alleviate the contradiction, a method of using the rear section waste gas as cooling air, using the middle section waste gas for hot air sintering and using a sintering machine to consume the ring cooler waste gas is presented. Although the prior art can basically solve the problem of unorganized exhaust of the exhaust gas of the circular cooler, the following problems still exist: 1) The method is characterized in that the method comprises the steps that a windbox section of the annular cooler is divided according to the working range of a cooling fan, each blower corresponds to a cooling section, the upper cover section of the annular cooler is basically corresponding to the windbox section, the heat-taking section of a waste heat boiler is the front two sections of the annular cooler, the area of the waste heat boiler is generally about 40% of the total area of the annular cooler, waste gas taken out from the upper covers of the front two sections of the annular cooler is sent back to the front two sections of the annular cooler by a waste heat circulating fan to serve as cooling air after heat exchange, the part of waste gas is self-circulated in the front two sections of the annular cooler and limited by the sections, the heat-taking area of the waste heat boiler is relatively fixed, and a large amount of low-temperature waste gas waste heat in the middle and rear sections of the annular cooler cannot be recovered by the waste heat boiler; 2) The heat extraction range of the waste heat boiler is basically fixed under the sectional limitation of the air box and the upper cover of the annular cooler, and when the sintering production fluctuates, the temperature of hot waste gas at the front part of the annular cooler also fluctuates, once the fluctuation of the air temperature at the inlet of the boiler deviates from the normal working range of the boiler, the working state of the waste heat boiler is influenced, and even the steam turbine of the waste heat power generation system is stopped. In the actual production process, the air temperature of the inlet of the waste heat boiler is generally adjusted by adjusting the air quantity of a corresponding back-heating fan of the waste heat boiler or by adding cold air, so that the adjusting mode has high difficulty, when the adjusting mode does not work, the air temperature of the inlet of the waste heat boiler is ensured by adjusting sintering production operation, and the phenomenon that the sintering production is inverted at the end of waste heat recovery service occurs; 3) Under the prior art condition, after cascade utilization, the annular cooler still needs to discharge larger exhaust gas, if the sintering machine is required to completely consume the exhaust gas discharged by the annular cooler, a long fan housing is required to be arranged above the material surface of the sintering machine, a large proportion of sintering area is utilized to absorb the exhaust gas, when the sintering flue gas circulation technology is adopted, a certain proportion of sintering area is also required to absorb the circulating flue gas, the space for absorbing the exhaust gas of the annular cooler through the sintering machine can be compressed, the pr