阅读说明：本技术 一种高炉煤气高效降温系统及方法 (High-efficiency cooling system and method for blast furnace gas ) 是由 徐伟 张天赋 矫继东 赵伟 何嵩 张函 陈鹏 高军 张炎 马光宇 于 2021-01-06 设计创作，主要内容包括：本发明涉及钢铁行业冶金煤气高效应用的技术领域,尤其涉及一种高炉煤气高效降温系统及方法。系统包括通过管路相连的高炉、炉顶喷雾装置、干法除尘装置、TRT发电装置、旁路喷雾装置、脱湿装置、旁路减压阀组、煤气降温塔、循环水冷却塔、循环水水池、CCPP发电装置与水泵。一种高炉煤气高效降温方法,具体包括两种运行状态,一是TRT发电装置运行状态,二是TRT发电装置停止运行状态。针对部分高炉产出的高炉荒煤气长期处于较高的250℃～300℃温度范围,实现了对高炉煤气的高效降温,在不明显增加循环水量的前提下,满足了早期湿法除尘工艺配套下CCPP发电机组对高炉煤气温度需求,解决了钢铁行业高炉煤气湿法除尘改干法除尘的制约瓶颈。(The invention relates to the technical field of high-efficiency application of metallurgical coal gas in the steel industry, in particular to a high-efficiency cooling system and a high-efficiency cooling method for blast furnace coal gas. The system comprises a blast furnace, a furnace top spraying device, a dry-method dust removal device, a TRT power generation device, a bypass spraying device, a dehumidification device, a bypass pressure-reducing valve bank, a coal gas cooling tower, a circulating water pool, a CCPP power generation device and a water pump which are connected through pipelines. A blast furnace gas efficient cooling method specifically comprises two operation states, namely a TRT power generation device operation state and a TRT power generation device stop operation state. Aiming at the condition that part of blast furnace raw gas produced by the blast furnace is in a higher temperature range of 250-300 ℃ for a long time, the blast furnace gas is efficiently cooled, the requirement of a CCPP generator set on the blast furnace gas temperature under the matching of an early wet dust removal process is met on the premise of not obviously increasing the circulating water amount, and the restriction bottleneck of changing the wet dust removal method into the dry dust removal method for the blast furnace gas in the steel industry is solved.)

1. A high-efficiency cooling system for blast furnace gas is characterized by comprising a furnace top spraying device, a dry dust removal device, a bypass spraying device, a dehumidification device, a bypass pressure reducing valve bank, a gas cooling tower, a circulating water cooling tower and a circulating water pool;

the devices are connected through pipelines, a gas outlet of the blast furnace is connected with a furnace top spraying device, and the gas outlet of the furnace top spraying device is connected with an inlet of a dry dust removal device;

the coal gas outlet of the dry dust removal device is connected with the TRT power generation device and the inlet of the bypass spraying device, the outlet of the bypass spraying device is connected with the inlet of the dehumidification device, and the outlet of the dehumidification device is connected with the inlet of the bypass pressure reducing valve bank;

the gas outlet of the TRT power generation device and the bypass pressure reducing valve set is connected with the gas inlet of the gas cooling tower, and the gas outlet of the gas cooling tower is connected with the inlet of the CCPP power generation device;

the cooling water outlet of the gas cooling tower is connected with the inlet of the circulating water cooling tower, the outlet of the circulating water cooling tower is connected with the inlet of the circulating water pool, and the outlet of the circulating water pool is connected with the cooling water inlet of the gas cooling tower.

2. The blast furnace gas high-efficiency cooling system according to claim 1, further comprising a valve and a water pump.

3. The blast furnace gas high-efficiency cooling system according to claim 2, wherein the water pump is installed on a connecting pipeline between an outlet of the circulating water pond and a cooling water inlet of the gas cooling tower.

4. The blast furnace gas high-efficiency cooling method based on the blast furnace gas high-efficiency cooling system of claim 1 is characterized by comprising the operation state of a TRT power generation device;

in the operation state of the TRT power generation device:

1) blast furnace gas generated in blast furnace smelting and with the temperature higher than 180-200 ℃ is sent into a furnace top spraying device for spraying and cooling, and the water content of the blast furnace gas after cooling is controlled at 10g/Nm³～40g/Nm³；

2) The blast furnace gas temperature lower than 180-200 ℃ after being cooled by spraying enters a dry dust removal device, the blast furnace gas after being dedusted by the dry dust removal device enters a TRT power generation device, the residual pressure and the waste heat are utilized for power generation, the blast furnace gas temperature after coming out of the TRT power generation device is in the range of 60-80 ℃, the water content is 10g/Nm³～40g/Nm³The dew point temperature is lower than 35 ℃;

3) the blast furnace gas flows upwards from the bottom of the gas cooling tower and carries out countercurrent heat exchange with spray water on the upper part of the gas cooling tower, the blast furnace gas is cooled by utilizing sensible heat of the spray water, and the temperature of the gas is reduced to below 35 ℃ by controlling the water amount of the spray water.

5. The method for efficiently cooling blast furnace gas according to claim 4, wherein in the operating state of the TRT power generation plant:

after heat exchange, the temperature of spray water is raised to 30 ℃, the spray water enters a circulating water cooling tower from a waterway outlet at the bottom of the gas cooling tower, is cooled to 25 ℃ by the cooling tower and flows into a circulating water pool, and then cooling water in the circulating water pool is circularly pumped into the gas cooling tower by a water pump to cool blast furnace gas.

6. The blast furnace gas high-efficiency cooling method according to claim 4, further comprising a TRT power generation device stop state;

in the stop operation state of the TRT power generation device:

1) blast furnace gas generated in blast furnace smelting and with the temperature higher than 180-200 ℃ is sent into a furnace top spraying device for spraying and cooling, and the water content of the blast furnace gas after cooling is controlled at 10g/Nm³～40g/Nm³；

2) The blast furnace gas with the temperature lower than 180-200 ℃ after being cooled by spraying enters a dry dust removal device, the blast furnace gas after being removed dust by the dry dust removal device enters a bypass pressure reducing valve group for pressure reduction, then enters a bypass spraying device for temperature reduction, and sprayed and atomized water drops absorb the heat of the blast furnace gas and are vaporized into water vapor to cool the blast furnace gas to the range of 100-120 ℃;

3) the water content of the blast furnace gas after temperature reduction is 50g/Nm³～90g/Nm³The pressure is 230 Kp-240 Kp, and the corresponding dew point temperature is 59-72 ℃; the blast furnace gas after the bypass spray cooling enters a dehumidifying device, the dehumidifying device adopts a membrane separation technology, when the blast furnace gas flows through one side of a high-molecular separation membrane, water vapor enters the other side through the membrane to be discharged under the action of pressure difference between the two sides of the membrane, and dry blast furnace gas is left;

4) after passing through the dehumidification device, the water vapor removal efficiency of the blast furnace gas reaches over 90 percent, and the water content of the blast furnace gas is reduced to 5g/Nm³～9g/Nm³Reducing the pressure of the dehumidified blast furnace gas to 13 Kp-16 Kp by a bypass pressure reducing valve group, wherein the dew point temperature of the blast furnace gas is lower than 35 ℃;

5) the blast furnace gas after dehumidification and pressure reduction flows upwards from the bottom of the gas cooling tower to perform countercurrent heat exchange with spray water on the upper part of the gas cooling tower, the blast furnace gas is cooled by utilizing sensible heat of the spray water, and the temperature of the gas is reduced to below 35 ℃ by controlling the water amount of the spray water;

6) in the operation process, the blast furnace gas dehumidified by the dehumidifying device is used as a purging gas source to purge and separate accumulated water on the downstream side of the polymer separation membrane, and the purged and separated water is discharged through a drainer or flows back to a circulating water pool to serve as water supplement.

7. The method for efficiently cooling blast furnace gas according to claim 6, wherein in a state where the TRT power generation plant is not in operation: the temperature of spray water is raised to 30 ℃ after heat exchange, the spray water enters a circulating water cooling tower from a waterway outlet at the bottom of the gas cooling tower, is cooled to 25 ℃ through the cooling tower and flows into a circulating water pool, and then cooling water in the circulating water pool is circularly pumped into the gas cooling tower by a water pump to cool blast furnace gas.

Technical Field

The invention relates to the technical field of high-efficiency application of metallurgical coal gas in the steel industry, in particular to a high-efficiency cooling system and a high-efficiency cooling method for blast furnace coal gas.

Background

The blast furnace gas dust removal process of the iron and steel enterprises is divided into dry dust removal and wet dust removal, the large blast furnace gas dust removal process put into production in early stage in China basically adopts a wet dust removal mode, the wet dust removal process can lose part of gas excess pressure and heat energy, sewage ring water for gas washing is difficult to treat, small particles can be circulated and enriched in a sewage ring water treatment system, and finally discharged to cause secondary environmental pollution. With the improvement of the cloth bag technology in recent years, the problem that the cloth bag is easy to damage at the furnace top temperature of 180-300 ℃ is solved, and the dry dust removal becomes the first choice of the blast furnace gas dust removal mode of various large steel plants.

Compared with the wet method, the dry method dust removal method has the advantages that not only can the pressure energy of blast furnace gas be fully utilized, but also the sensible heat of the gas is fully utilized, so that the energy which can be recovered by the TRT device is greatly increased. However, the CCPP generator set matched with the original wet dust removal is designed according to the temperature of blast furnace gas after the wet dust removal at the beginning of design, and the temperature of the inlet gas is required to be about 35-40 ℃, particularly, in the early large CCPP generator set, for example, a saddle steel 300MW large CCPP generator set, the temperature of the inlet blast furnace gas is required to be not higher than 35 ℃, and the CCPP cannot run at full load to reduce the power generation.

Although the wet method for blast furnace gas dust removal is changed into the dry method, the TRT power generation can be improved, if the problem that the temperature of blast furnace gas is too high cannot be solved, the CCPP power generation is influenced, which is irrecoverable, and is also a main reason for restricting a plurality of iron and steel enterprises from being incapable of carrying out dry method modification on blast furnace gas. Therefore, it is necessary to study the temperature reduction of blast furnace gas under dry dedusting to meet the requirements of the subsequent CCPP operation.

CN107604116A discloses a blast furnace gas processing system and a processing method thereof, in the method, the temperature of the gas is controlled by a TRT power generation device, although the temperature of the gas can be controlled in a certain range, the temperature of the gas is controlled at the expense of power generation efficiency, which is irrecoverable, and there is a certain controversy. CN105950226A discloses a vertical gas spraying, cooling and dewatering integrated system, which utilizes water atomized water to spray and cool high-temperature gas, wash acid substances and salt, and rotate the gas containing mechanical water in a vertical gas dewatering device to remove mechanical water drops, but the pipeline spraying and cooling method is difficult to reduce the temperature of blast furnace gas to about 35-40 ℃. CN201525851U discloses a "gas cooling device for a blast furnace gas dry dedusting process", which sprays atomized cooling water into a pipeline through a double-medium atomizing nozzle installed on a blast furnace gas pipeline to cool the blast furnace gas, so that the blast furnace gas enters a dry deduster without burning filter materials in the deduster; but the device does not consider the requirements of subsequent gas users on the gas temperature.

In summary, the blast furnace gas cooling system and the method have some problems. The blast furnace gas cooling system and the blast furnace gas cooling method mainly reflect that when part of blast furnace gas produced by a blast furnace is at a high temperature for a long time, the blast furnace gas can not be effectively cooled to about 35 ℃ by the existing blast furnace gas cooling system and method after the original wet dust removal process is changed into the dry dust removal process, so that the temperature requirement of a CCPP (CCPP) generator set matched with the early wet dust removal process can be met. Therefore, it is necessary to find a more practical and effective high-efficiency blast furnace gas cooling system and method.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a high-efficiency cooling system and a high-efficiency cooling method for blast furnace gas, aiming at the problem that part of blast furnace gas produced by a blast furnace is in a higher temperature range of 250-300 ℃ for a long time. The high-efficiency cooling of the blast furnace gas is realized, the requirement of a CCPP power generator set on the blast furnace gas temperature under the matching of an early wet dust removal process is met on the premise of not obviously increasing the circulating water amount, and the restriction bottleneck of changing the wet dust removal method into the dry dust removal method for the blast furnace gas in the steel industry is solved.

In order to achieve the purpose, the invention adopts the following technical scheme:

a high-efficiency cooling system for blast furnace gas comprises a furnace top spraying device, a dry dust removal device, a bypass spraying device, a dehumidifying device, a bypass pressure reducing valve bank, a gas cooling tower, a circulating water cooling tower and a circulating water pool;

the devices are connected through pipelines, a gas outlet of the blast furnace is connected with a furnace top spraying device, and the gas outlet of the furnace top spraying device is connected with an inlet of a dry dust removal device;

the coal gas outlet of the dry dust removal device is connected with the TRT power generation device and the inlet of the bypass spraying device, the outlet of the bypass spraying device is connected with the inlet of the dehumidification device, and the outlet of the dehumidification device is connected with the inlet of the bypass pressure reducing valve bank;

the dehumidifying device adopts an efficient membrane separation technology to dehumidify;

the gas outlet of the TRT power generation device and the bypass pressure reducing valve set is connected with the gas inlet of the gas cooling tower, and the gas outlet of the gas cooling tower is connected with the inlet of the CCPP power generation device;

the cooling water outlet of the gas cooling tower is connected with the inlet of the circulating water cooling tower, the outlet of the circulating water cooling tower is connected with the inlet of the circulating water pool, and the outlet of the circulating water pool is connected with the cooling water inlet of the gas cooling tower.

Also comprises a valve and a water pump.

The water pump is arranged on a connecting pipeline between the outlet of the circulating water tank and the cooling water inlet of the coal gas cooling tower.

A blast furnace gas efficient cooling method specifically comprises two operation states, namely a TRT power generation device operation state and a TRT power generation device stop operation state.

Under the operation state of the TRT power generation device:

1) the temperature of blast furnace gas generated in blast furnace smelting is generally above 220 ℃, and can change along with the fluctuation of the blast furnace condition, even the temperature of blast furnace top raw gas can be in the range of about 250-300 ℃ for a long time; the generated blast furnace gas enters a furnace top spraying device, if the temperature is higher than 180-200 ℃, spraying cooling is carried out, and sprayed fog drops absorb the sensible heat of the blast furnace gas and vaporize into water vapor so as to achieve the purpose of cooling the blast furnace gas; if the temperature is not higher than 180-200 ℃, the spraying cooling is not carried out; the water content of the blast furnace gas at the outlet of the furnace top spraying device after the temperature is reduced is 10g/Nm³～40g/Nm³。

2) The furnace top spraying device ensures that the temperature of blast furnace gas is lower than 180-200 ℃ and enters the dry dust removal device to prevent the cloth bag filter material in the dry dust removal device from being burnt out due to overhigh temperature of the gas; the blast furnace gas enters a TRT power generation device after being dedusted by a dry dedusting device, the residual pressure and the waste heat are utilized for power generation, the temperature of the blast furnace gas after coming out of the TRT power generation device is generally in the range of 60-80 ℃, and the water content is 10g/Nm³～40g/Nm³The dew point temperature is lower than 35 ℃.

3) The blast furnace gas flows upwards from the bottom of the gas cooling tower and carries out countercurrent heat exchange with spray water on the upper part of the gas cooling tower, the blast furnace gas is cooled by utilizing sensible heat of the spray water, and the temperature of the gas is reduced to below 35 ℃ by controlling the water amount of the spray water.

4) The temperature of the spray water is raised to 30 ℃ after heat exchange, the spray water enters a circulating water cooling tower from a waterway outlet at the bottom of the gas cooling tower, is cooled to 25 ℃ through the cooling tower and flows into a circulating water pool, and then cooling water in the circulating water pool is circularly pumped into the gas cooling tower by a water pump to cool the blast furnace gas.

In the stop operation state of the TRT power generation device:

1) the temperature of blast furnace gas generated in blast furnace smelting is generally above 220 ℃; the generated blast furnace gas enters a furnace top spraying device, and if the temperature is higher than 180-200 ℃, spraying and cooling are carried out; if the temperature is not higher than 180-200 ℃, the spraying cooling is not carried out; content of outlet blast furnace gas after temperature reduction of furnace top spraying deviceThe water amount is 10g/Nm³～40g/Nm³；

2) The furnace top spraying device ensures that the temperature of blast furnace gas is lower than 180-200 ℃ and enters a dry dust removal device; the blast furnace gas is dedusted by the dry dedusting device and enters the bypass spraying device for cooling, the sprayed and atomized water drops absorb the heat of the blast furnace gas and are vaporized into water vapor, and the blast furnace gas is cooled to be within the range of 100-120 ℃.

3) The water content of the blast furnace gas after temperature reduction is 50g/Nm³～90g/Nm³The pressure is about 230 Kp-240 Kp generally, and the corresponding dew point temperature is 59-72 ℃; if the blast furnace gas in the state directly enters the gas cooling tower to be cooled to 35 ℃ and can be cooled to below the dew point temperature of the blast furnace gas, most of the cold energy provided by the circulating water of the gas cooling tower is used for latent heat cold absorption of water by water vapor cooling, and the amount of the circulating water is expected to be increased by 25-90%; in order to ensure that the difference between the circulating water amount of the gas cooling tower in the operation state and the fault state of the TRT power generation device is not large, the blast furnace gas after being cooled by the bypass spray enters a dehumidifying device which adopts a membrane separation technology, when the blast furnace gas flows through one side of a high-molecular separation membrane, under the action of the pressure difference of the two sides of the membrane, water vapor enters the other side through the membrane to be discharged, and dry blast furnace gas is remained;

4) the process belongs to a gas membrane separation process, and the process utilizes the self pressure of blast furnace gas to operate without external energy. After passing through the dehumidification device, the water vapor removal efficiency of the blast furnace gas reaches over 90 percent, and the water content of the blast furnace gas is reduced to 5g/Nm³～9g/Nm³The pressure of the dehumidified blast furnace gas is reduced to 13 Kp-16 Kp by a bypass pressure reducing valve group, and the dew point temperature of the blast furnace gas is far lower than 35 ℃;

5) the blast furnace gas after dehumidification and pressure reduction flows upwards from the bottom of the gas cooling tower to perform countercurrent heat exchange with spray water on the upper part of the gas cooling tower, the blast furnace gas is cooled by utilizing sensible heat of the spray water, and the temperature of the gas is reduced to below 35 ℃ by controlling the water amount of the spray water.

6) The temperature of the spray water is raised to 30 ℃ after heat exchange, the spray water enters a circulating water cooling tower from a waterway outlet at the bottom of the gas cooling tower, is cooled to 25 ℃ through the cooling tower and flows into a circulating water pool, and then cooling water in the circulating water pool is circularly pumped into the gas cooling tower by a water pump to cool the blast furnace gas.

7) Along with the operation of the dehumidifying device, water vapor can be accumulated on the surface of a downstream side membrane after penetrating through the polymer separation membrane, so that the concentration polarization phenomenon is caused, the membrane separation efficiency is reduced, and the dehumidifying effect is reduced; therefore, accumulated water on the downstream side of the polymer separation membrane needs to be swept and separated in the operation process, the membrane separation water vapor removal efficiency is ensured to be over 90%, and a sweeping gas source can utilize blast furnace gas dehumidified by a dehumidification device; the water separated by purging is discharged through a drainer or can be returned to the circulating water pool as the water supplement.

Compared with the prior art, the invention has the beneficial effects that:

by using the TRT bypass spraying device and the dehumidifying device, the invention ensures that the blast furnace gas produced by the blast furnace is in a higher temperature range of 250-300 ℃ for a long time, and can also control the temperature and the moisture content of the gas entering the gas cooling tower when the TRT power generation device stops operating, and the temperature and the moisture content of the gas entering the gas cooling tower are not greatly different from those of the gas entering the gas cooling tower when the TRT power generation device operates; on the premise of not obviously increasing the circulating water quantity, the circulating water quantity of the gas cooling tower is ensured not to generate large fluctuation, the cooling effect of the gas cooling tower on the temperature of blast furnace gas to be reduced to 35 ℃ is also ensured, and the operation stability and reliability of the whole gas cooling system are improved.

Drawings

FIG. 1 is a schematic diagram of the structure and process of the present invention.

In the figure:

1. the system comprises a blast furnace, 2, a furnace top spraying device, 3, a dry dust removal device, 4, a TRT power generation device, 5, a bypass spraying device, 6, a dehumidification device, 7, a bypass pressure reducing valve bank, 8, a coal gas cooling tower, 9, a circulating water cooling tower, 10, a circulating water pool, 11, a CCPP power generation device, 12, a water pump, 13, 14, 15, 16 switch valves and 17 switch adjusting valves.

Detailed Description

The invention discloses a high-efficiency cooling system and a high-efficiency cooling method for blast furnace gas. Those skilled in the art can modify the process parameters appropriately to achieve the desired results with reference to the disclosure herein. It is expressly intended that all such similar substitutes and modifications which would be obvious to one skilled in the art are deemed to be included in the invention. While the methods and applications of this invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and modifications in the methods and applications described herein, as well as other suitable variations and combinations, may be made to implement and use the techniques of this invention without departing from the spirit and scope of the invention.

A blast furnace gas high-efficiency cooling system comprises a furnace top spraying device 2, a dry dust removal device 3, a bypass spraying device 5, a dehumidification device 6, a bypass pressure reducing valve bank 7, a gas cooling tower 8, a circulating water cooling tower 9, a circulating water pool 10, a water pump 12, switch valves 13, 14, 15 and 16 and a switch regulating valve 17.

Wherein the gas outlet of the blast furnace 1 is connected with the furnace top spraying device 2, the gas outlet of the furnace top spraying device 2 is connected with the inlet of the dry dust removal device 3, the gas outlet of the dry dust removal device 3 is connected with the inlets of the TRT power generation device 4 and the bypass spraying device 5, the outlet of the bypass spraying device 5 is connected with the inlet of the dehumidifying device 6, and the outlet of the dehumidifying device 6 is connected with the inlet of the bypass pressure reducing valve bank 7.

Meanwhile, the TRT power generation device 4 and the coal gas outlet of the bypass pressure reducing valve group 7 are connected with the coal gas inlet of the coal gas cooling tower 8, and the coal gas outlet of the coal gas cooling tower 8 is connected with the inlet of the CCPP power generation device 11; the cooling water outlet of the coal gas cooling tower 8 is connected with the inlet of a circulating water cooling tower 9, the outlet of the circulating water cooling tower 9 is connected with the inlet of a circulating water pool 10, and the outlet of the circulating water pool 10 is connected with the cooling water inlet of the coal gas cooling tower 8. A water pump 12 is arranged on a pipeline connecting the outlet of the circulating water pool 10 and the cooling water inlet of the coal gas cooling tower 8.

A switching valve 13 is arranged on a pipeline connecting the dry dust removal device 3 and the bypass spraying device 5, a switching valve 14 is arranged on a pipeline at the outlet of the bypass pressure reducing valve bank 7, a switching valve 15 is arranged on a pipeline connecting the dry dust removal device 3 and the TRT power generation device 4, a switching valve 16 is arranged on a pipeline at the outlet of the TRT power generation device 4, and a switching regulating valve 17 is arranged on a pipeline connecting the outlet of the dehumidification device 6 and the inlet of the bypass pressure reducing valve bank 7.

Example 1:

a blast furnace gas high-efficiency cooling method is characterized in that in the running state of a TRT power generation device:

in the TRT power plant operating state, the on-off valves 15, 16 are in the open state, and the on-off valves 13, 14 and the on-off regulating valve 17 are in the closed state.

The temperature of blast furnace gas generated in a blast furnace 1 is 280 ℃, the blast furnace gas enters a furnace top spraying device 2, the furnace top spraying device 2 sprays and atomizes water with the temperature of 25 ℃, sprayed fog drops absorb the sensible heat of the blast furnace gas and are vaporized into water vapor to achieve the purpose of cooling the blast furnace gas, the temperature of the blast furnace gas is reduced to 200 ℃, and the water content of the blast furnace gas at the outlet of the furnace top spraying device 2 is 38.7g/Nm³Left and right.

The blast furnace gas after temperature reduction is dedusted by a dry dedusting device 3 and then enters a TRT power generation device 4, the residual pressure and the waste heat are utilized for power generation, the temperature of the blast furnace gas after coming out of the TRT power generation device 4 is 75 ℃, and the water content is 38.7g/Nm³The pressure was 16Kp and the dew point temperature was 34 ℃.

Blast furnace gas at 75 ℃ flows upwards from the bottom of the gas cooling tower 8 and carries out countercurrent heat exchange with spray water on the upper part of the gas cooling tower 8, the blast furnace gas is cooled by utilizing sensible heat of the spray water, the outlet temperature of the blast furnace gas is reduced to about 35 ℃ by controlling the water amount of the spray water, and the cooled blast furnace gas is supplied to the CCPP power generation device 11 for power generation.

The temperature of spray water in the gas cooling tower 8 is 25 ℃, the temperature of the spray water is raised to 30 ℃ after heat exchange, the spray water enters a circulating water cooling tower 9 from a water channel at the bottom of the gas cooling tower 8, the spray water is cooled to 25 ℃ through the cooling tower and flows into a circulating water pool 10, and cooling water in the circulating water pool 10 circularly enters the gas cooling tower 8 through a water pump 12 to cool blast furnace gas.

Example 2:

a blast furnace gas high-efficiency cooling method is characterized in that when a TRT power generation device stops operating:

in the TRT power plant shutdown state, the on-off valves 13 and 14 and the on-off regulating valve 17 are in the open state, and the on-off valves 15 and 16 are in the closed state.

The temperature of blast furnace gas generated in a blast furnace 1 is 280 ℃, the blast furnace gas enters a furnace top spraying device 2, the furnace top spraying device 2 sprays and atomizes water with the temperature of 25 ℃, sprayed fog drops absorb the sensible heat of the blast furnace gas and are vaporized into water vapor to achieve the purpose of cooling the blast furnace gas, the temperature of the blast furnace gas is reduced to 200 ℃, and the water content of the blast furnace gas at the outlet of the furnace top spraying device 2 is 38.7g/Nm³Left and right.

Then, the blast furnace gas is dedusted by a dry dedusting device 3 and enters a bypass spraying device 5 for secondary cooling, the sprayed and atomized water drops absorb the heat of the blast furnace gas and are vaporized into steam, and the temperature of the blast furnace gas is reduced to 110 ℃; the water content of the blast furnace gas after temperature reduction is 88g/Nm³The pressure was about 235Kp, corresponding to a dew point temperature of about 71 ℃.

The cooled gas enters a dehumidifying device 6, the blast furnace gas flows through one side of a high-molecular separation membrane by virtue of self pressure, water vapor enters the other side of the membrane to be discharged under the action of pressure difference between the two sides of the membrane, the removing efficiency reaches over 90 percent, and the water content of the blast furnace gas is reduced to 8.8g/Nm³Left and right.

In the dehumidifying device 6, a small amount of dehumidified blast furnace gas is led back to be used as a gas source for sweeping and separating accumulated water on the downstream side of the polymer separation membrane through a switch regulating valve 17, and the separated water is discharged; the pressure of the dehumidified blast furnace gas is reduced to 15Kp by a bypass pressure reducing valve bank 7, and the dew point temperature of the blast furnace gas is far lower than 35 ℃.

Then, the blast furnace gas flows upwards from the bottom of the gas cooling tower 8 and carries out countercurrent heat exchange with spray water on the upper part of the gas cooling tower 8, the blast furnace gas is cooled by utilizing sensible heat of the spray water, the temperature of the blast furnace gas is reduced to be below 35 ℃, and the cooled blast furnace gas is supplied to a CCPP power generation device 11 for power generation.

The temperature of the spray water is 25 ℃, the temperature of the spray water is raised to 30 ℃ after heat exchange, the spray water enters a circulating water cooling tower 9 from a water channel at the bottom of the gas cooling tower 8, the spray water is cooled to 25 ℃ through the cooling tower and flows into a circulating water pool 10, and cooling water in the circulating water pool 10 circularly enters the gas cooling tower 8 through a water pump 12 to circularly cool the blast furnace gas.

According to the invention, through the use of the TRT bypass spraying device and the dehumidifying device, the temperature and the moisture content of the coal gas entering the coal gas cooling tower in the state that the TRT power generation device stops operating are controlled, and the difference between the temperature and the moisture content of the coal gas entering the coal gas cooling tower in the state that the TRT power generation device operates is not large; the circulating water quantity of the gas cooling tower is ensured not to fluctuate greatly, the cooling effect of the gas cooling tower on the temperature of blast furnace gas to be reduced to 35 ℃ is also ensured, and the operation stability and reliability of the whole gas cooling system are improved.

The invention solves the problem that the blast furnace gas temperature is not matched with the requirement of the CCPP power generation device after the blast furnace gas wet dust removal is changed into the dry dust removal, realizes the cooling of the blast furnace gas to 35 ℃, and ensures the requirement of the CCPP power generation device on the blast furnace gas temperature.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.