阅读说明：本技术 一种新型气化废锅工艺 (Novel gasification waste boiler process ) 是由 吴妙奇 黄习兵 潘怀民 闫晓洋 詹媛媛 廖晶慧 诸奇滨 郭永强 韩磊 张天宇 于 2021-08-30 设计创作，主要内容包括：本发明涉及一种新型气化废锅工艺,采用激冷环对高温合成气进行部分激冷,部分激冷后的合成气经过废锅回收热量,进废锅的合成气温度调节通过调节激冷环激冷水流量实现,下降管采用夹套方式,夹套内压力低于合成气侧压力,采用独立冷却循环回水系统,监测下降管在运行中是否被烧穿；下降管冷却夹套循环水分离罐压力可调,通过增加压力来提高循环水的热容,避免循环回水汽化；本发明不仅适用于气流床煤气化技术,也适用于油气化、气态烃气化等技术,适用于气流床气化的下降管改造；相比于带下降管式纯激冷流程,本工艺合成气的显热几乎可全部回收,可副产高品质蒸汽,热效率高；本工艺流程简单,控制方便,安全可靠,可减少装置占地,降低装置投资。(The invention relates to a novel gasification waste pot process, which adopts a chilling ring to partially chill high-temperature synthesis gas, the partially chilled synthesis gas recovers heat through a waste pot, the temperature of the synthesis gas entering the waste pot is adjusted by adjusting the chilling water flow of the chilling ring, a descending pipe adopts a jacket mode, the pressure in the jacket is lower than the pressure at the side of the synthesis gas, and an independent cooling circulating water return system is adopted to monitor whether the descending pipe is burnt through in the running process; the pressure of the circulating water separation tank of the cooling jacket of the downcomer is adjustable, the heat capacity of the circulating water is improved by increasing the pressure, and the circulating return water is prevented from being vaporized; the invention is not only suitable for the entrained flow bed coal gasification technology, but also suitable for the oil gasification, gaseous hydrocarbon gasification and other technologies, and is suitable for the downcomer modification of entrained flow bed gasification; compared with a pure chilling process with a lower descending pipe, the sensible heat of the synthesis gas can be almost completely recovered, high-quality steam can be produced as a byproduct, and the heat efficiency is high; the process flow is simple, the control is convenient, the safety and the reliability are realized, the occupied area of the device can be reduced, and the device investment is reduced.)

1. A novel gasification waste pot process is characterized by comprising the following steps:

1) chilling system

Firstly, the gasification raw material and the gasification agent enter a reaction chamber of a gasification furnace F01 through a burner A01 to carry out gasification reaction, and the reaction produces the product mainly containing CO and H₂The temperature of the high-temperature synthesis gas is 1500 ℃;

secondly, the high-temperature synthesis gas descends and is cooled by chilling water sprayed by a chilling ring, the molten ash is condensed into solid, and the temperature of the synthesis gas is controlled to 850 ℃ after cooling;

thirdly, the chilled synthetic gas at the temperature of 850 ℃ descends, is separated from ash at a break angle and is discharged out of the gasifier;

fourthly, opening a slag lock hopper feed valve XV02 after the slag in the gasification furnace is stored for a certain time;

2) waste heat recovery system

Firstly, the synthesis gas of-850 ℃ after the gasification furnace F01 is partially chilled enters a waste boiler E01, the synthesis gas is heated by a waste boiler E01 to reach the temperature of-350 ℃, and the synthesis gas is sent to the downstream;

secondly, conveying the deoxygenated water in the steam drum V01 to a waste boiler E01 through a high-pressure deoxygenation water pump P02, and cooling the synthesis gas, wherein the working pressure of the steam drum V01 is-10 MPa;

thirdly, the deoxidized water passing through the waste boiler E01 is partially vaporized to generate high-pressure steam, the steam-water mixed phase is discharged from the waste boiler E01 and enters a steam drum V01 for steam-water separation, and the high-pressure steam is sent to the downstream after passing through a steam drum pressure control valve PV 01;

3) downcomer protection system

Step one, boiler water in a circulating water separation tank V02 of a downcomer cooling jacket is pressurized by a circulating water pump P03 of the downcomer cooling jacket, enters the lower part of the downcomer jacket and goes upward along the downcomer jacket;

secondly, after passing through a descending pipe jacket, the circulating cooling water is heated, is led out from the top of the descending pipe jacket, enters the descending pipe cooling jacket and circulates back to the water cooler E02 and is cooled;

thirdly, the cooled circulating backwater enters a downcomer cooling jacket circulating water separation tank V02;

and fourthly, restarting the first step.

2. The novel gasification waste pot process of claim 1, wherein: the gasifier outlet synthesis gas is provided with temperature monitoring, and when the outlet synthesis gas temperature fluctuates, the chilling water flow is adjusted by adjusting the chilling water flow adjusting valve FV01 to control the synthesis gas temperature.

3. The novel gasification waste pot process of claim 2, wherein: the gasifier is provided with liquid level monitoring, and when the liquid level fluctuates, the liquid level of the gasifier is controlled to be stable by adjusting a gasifier liquid level control valve LV 01.

4. The novel gasification waste pot process of claim 1, wherein: the outlet of the high-pressure deoxygenation water pump P02 is provided with a flow monitor, and the outlet of the waste boiler E01 is provided with a synthetic gas temperature monitor; the temperature control of the synthesis gas at the outlet of the waste boiler E01 is realized by enough heat exchange area and enough flow of deoxygenated water, and the deoxygenated water amount is more than 20 times of the steam yield and is kept constant.

5. The novel gasification waste pot process of claim 4, wherein: the pressure of the steam drum V01 is regulated by a steam drum pressure control valve PV01, and the pressure of the steam drum is controlled to be higher than the highest operating pressure of the synthesis gas side, so that the synthesis gas does not enter the steam side in a reverse-serial mode when equipment leaks; the steam drum V01 adopts a three-impulse control and regulation system of by-product steam pressure PV01, steam drum liquid level LV02 and continuous blowdown FV 03.

6. The novel gasification waste pot process of claim 1, wherein: the outlet of a circulating water pump P03 of the cooling jacket of the downcomer is provided with flow monitoring, the outlet of circulating water of the jacket of the downcomer is provided with density monitoring, and the gas phase side of a circulating water separation tank V02 of the cooling jacket of the downcomer is provided with a CO monitor; the flow of circulating water is constant, the flow meets the condition that circulating backwater at the outlet of a descending pipe jacket does not generate vaporization, and whether vaporization occurs or not is monitored and judged by a density meter.

7. The novel gasification waste pot process of claim 6, wherein: the pressure of the circulating water in the jacket is lower than the lowest operating pressure of the synthesis gas side, and when the descending pipe is burnt through, the synthesis gas leaks to the circulating water side; the pressure of the circulating water separation tank V02 of the cooling jacket of the downcomer is adjustable, and the circulating water is prevented from being vaporized by increasing the pressure to improve the heat capacity of the circulating water through the split-range control of a pressurizing valve PV02 of the circulating water separation tank and a pressure release valve PV03 of the circulating water separation tank.

8. The novel gasification waste pot process of claim 7, wherein: when the liquid level of the circulating water separation tank V02 of the downcomer cooling jacket is low, boiler water is supplemented by opening a supplementary boiler water cut-off valve XV 01.

9. The novel gasification waste pot process as claimed in any one of claims 1 to 8, wherein: a downcomer high-temperature synthesis gas leading-out structure is arranged in the gasifier F01, the downcomer high-temperature synthesis gas leading-out structure is arranged in a chilling chamber at the lower part of the gasifier, and the upper end of the downcomer high-temperature synthesis gas leading-out structure is connected with a gasifier reaction chamber;

the leading-out structure consists of a straight pipe section and an inclined pipe leading-out section, the central line of the inclined pipe leading-out section and the central line of the straight pipe section form an angle alpha which is not more than 45 degrees, high-temperature synthetic gas containing molten ash from the gasification combustion chamber enters a chilling ring at the top of the straight pipe section through a synthetic gas inlet, the chilling ring continuously sprays chilling water, the high-temperature synthetic gas is fully contacted with the chilling water in the straight pipe section, the synthetic gas is cooled to below 850 ℃, the molten ash is cooled and solidified, most of solid ash is output from the lower end of the straight pipe section, the cooled synthetic gas is led out of the gasification furnace from the outlet end of the inclined pipe leading-out section, and gas-solid separation is realized in a descending pipe.

10. The novel gasification waste pot process of claim 9, wherein: in the inclined tube leading-out section, part of ash content carried by the synthesis gas is deposited on the tube wall under the action of gravity, slides to the straight tube section through the inclined tube leading-out section and enters a slag storage area of the gasification furnace; leading out the cooled synthesis gas from the inclined tube leading-out section and discharging the synthesis gas out of the gasifier; the straight pipe section and the inclined pipe leading-out section are both provided with cooling jackets for protecting a down pipe, cooling water in the jacket of the straight pipe section enters from the lower part and is led out from the lower edge of the straight pipe section close to the chilling ring, and cooling water in the jacket of the inclined pipe leading-out section enters from the bottom of the inclined pipe leading-out section and is led out from the top of the inclined pipe leading-out section; the lower end of the cooling jacket of the straight pipe section is more than 0.5 m below the liquid level of the gasification furnace, so that the high-temperature synthesis gas is protected from burning through a downcomer which is not provided with the cooling jacket.

Technical Field

The invention relates to a novel gasification waste boiler process.

Background

The currently applied flow of the entrained flow coal gasification process is divided into chilling and waste boiler flows, wherein the entrained flow chilling flow is generally provided with a chilling ring and a downcomer in a gasification furnace, and high-temperature synthesis gas passes through the chilling ring and then enters a water bath through the downcomer. The waste boiler process can be divided into two processes, one is a synthesis gas chilling process represented by a shell and a Huaneng furnace, namely, the synthesis gas after high-temperature synthesis gas is washed and cooled by downstream water is mixed and chilled and then the heat is recovered in the waste boiler; the other is a semi-waste pot process represented by Jinhua furnace, namely, high-temperature synthetic gas firstly passes through a radiation waste pot before entering a water bath for chilling, and then is chilled after the temperature of the high-temperature synthetic gas is reduced to below 900 ℃ after passing through the radiation waste pot.

At present, the entrained flow gasification chilling process is widely applied, the chilling process refers to that high-temperature synthetic gas at 1500 ℃ (pulverized coal and coal water slurry have differences) is directly cooled by chilling water, high-temperature heat is reflected by water vapor carried by the synthetic gas, and compared with a waste boiler process, the thermal efficiency is relatively low. Meanwhile, in the existing waste boiler process, a synthetic gas chilling mode is adopted before the waste boiler, a circulating gas compressor is required to be arranged in the process, and the process is complex to set.

For a pure chilling process, high-temperature synthesis gas is cooled by chilling water, high-temperature heat is reflected by the synthesis gas carrying water vapor, high-quality steam cannot be produced as a byproduct, and the overall thermal efficiency is relatively low; for the waste boiler process of chilling the synthesis gas, a recycle gas compressor is required to be arranged in the process, the process is complex, and the investment is high; for the semi-waste boiler process, the high-temperature heat carried by the synthesis gas is not fully utilized, and a great deal of heat is still lost in the form of water vapor carried by the synthesis gas.

Disclosure of Invention

The invention aims to solve the technical problem of the prior art and provides a novel gasification waste boiler process which fully recovers high-temperature sensible heat of synthesis gas, simplifies flow configuration and reduces device investment by partially chilling the synthesis gas through chilling water and further recovering heat through a waste boiler.

The technical scheme adopted by the invention for solving the technical problems is as follows: a novel gasification waste pot process is characterized by comprising the following steps:

1) chilling system

Firstly, the gasification raw material and the gasification agent enter a reaction chamber of a gasification furnace F01 through a burner A01 to carry out gasification reaction, and the reaction produces the product mainly containing CO and H₂The temperature of the high-temperature synthesis gas is 1500 ℃;

secondly, the high-temperature synthesis gas descends and is cooled by chilling water sprayed by a chilling ring, the molten ash is condensed into solid, and the temperature of the synthesis gas is controlled to 850 ℃ after cooling;

thirdly, the chilled synthetic gas at the temperature of 850 ℃ descends, is separated from ash at a break angle and is discharged out of the gasifier;

fourthly, opening a slag lock hopper feed valve XV02 after the slag in the gasification furnace is stored for a certain time;

2) waste heat recovery system

Firstly, the synthesis gas of-850 ℃ after the gasification furnace F01 is partially chilled enters a waste boiler E01, the synthesis gas is heated by a waste boiler E01 to reach the temperature of-350 ℃, and the synthesis gas is sent to the downstream;

secondly, conveying the deoxygenated water in the steam drum V01 to a waste boiler E01 through a high-pressure deoxygenation water pump P02, and cooling the synthesis gas, wherein the working pressure of the steam drum V01 is-10 MPa;

thirdly, the deoxidized water passing through the waste boiler E01 is partially vaporized to generate high-pressure steam, the steam-water mixed phase is discharged from the waste boiler E01 and enters a steam drum V01 for steam-water separation, and the high-pressure steam is sent to the downstream after passing through a steam drum pressure control valve PV 01;

3) downcomer protection system

Step one, boiler water in a circulating water separation tank V02 of a downcomer cooling jacket is pressurized by a circulating water pump P03 of the downcomer cooling jacket, enters the lower part of the downcomer jacket and goes upward along the downcomer jacket;

secondly, after passing through a descending pipe jacket, the circulating cooling water is heated, is led out from the top of the descending pipe jacket, enters the descending pipe cooling jacket and circulates back to the water cooler E02 and is cooled;

thirdly, the cooled circulating backwater enters a downcomer cooling jacket circulating water separation tank V02;

and fourthly, restarting the first step.

Preferably, the gasifier outlet synthesis gas is provided with temperature monitoring, and when the outlet synthesis gas temperature fluctuates, the chilling water flow is adjusted by adjusting the chilling water flow adjusting valve FV01 to control the synthesis gas temperature.

Preferably, the gasification furnace is provided with liquid level monitoring, and when the liquid level fluctuates, the liquid level of the gasification furnace is controlled to be stable by adjusting a gasification furnace liquid level control valve LV 01.

Preferably, the outlet of the high-pressure deoxygenation water pump P02 is provided with a flow monitor, and the outlet of the waste boiler E01 is provided with a synthetic gas temperature monitor; the temperature control of the synthesis gas at the outlet of the waste boiler E01 is realized by enough heat exchange area and enough flow of deoxygenated water, and the deoxygenated water amount is more than 20 times of the steam yield and is kept constant.

Preferably, the pressure of the steam drum V01 is regulated by a steam drum pressure control valve PV01, and the pressure of the steam drum is controlled to be higher than the highest operation pressure of the synthesis gas side, so that the synthesis gas does not enter the steam side in a back-crossing mode when the equipment leaks; the steam drum V01 adopts a three-impulse control and regulation system of by-product steam pressure PV01, steam drum liquid level LV02 and continuous blowdown FV 03.

Preferably, a flow rate monitor is arranged at an outlet of a circulating water pump P03 of the cooling jacket of the downcomer, a density monitor is arranged at a circulating water outlet of the jacket of the downcomer, and a CO monitor is arranged at the gas phase side of a circulating water separation tank V02 of the cooling jacket of the downcomer; the flow of circulating water is constant, the flow meets the condition that circulating backwater at the outlet of a descending pipe jacket does not generate vaporization, and whether vaporization occurs or not is monitored and judged by a density meter.

Preferably, the pressure of the circulating water in the jacket is lower than the lowest operating pressure on the synthesis gas side, and the synthesis gas leaks to the circulating water side when the downcomer is burned through; the pressure of the circulating water separation tank V02 of the cooling jacket of the downcomer is adjustable, and the circulating water is prevented from being vaporized by increasing the pressure to improve the heat capacity of the circulating water through the split-range control of a pressurizing valve PV02 of the circulating water separation tank and a pressure release valve PV03 of the circulating water separation tank.

Preferably, when the liquid level of the circulating water separation tank V02 of the downcomer cooling jacket is low, the boiler water is supplemented by opening a supplementary boiler water cut-off valve XV 01.

Preferably, a downcomer high-temperature synthesis gas leading-out structure is arranged in the gasification furnace F01, the downcomer high-temperature synthesis gas leading-out structure is arranged in a chilling chamber at the lower part of the gasification furnace, and the upper end of the downcomer high-temperature synthesis gas leading-out structure is connected with a gasification furnace reaction chamber;

the leading-out structure consists of a straight pipe section and an inclined pipe leading-out section, wherein the central line of the inclined pipe leading-out section and the central line of the straight pipe section form an angle alpha which is not more than 45 degrees, so that the ash settled in the synthesis gas is prevented from accumulating and blocking in the pipe; high-temperature synthesis gas containing molten ash from a gasification combustion chamber enters a chilling ring at the top of a straight pipe section through a synthesis gas inlet, the chilling ring continuously sprays chilling water, the high-temperature synthesis gas is fully contacted with the chilling water in the straight pipe section, the synthesis gas is cooled to below 850 ℃, the molten ash is cooled and solidified, most of solid ash is output from the lower end of the straight pipe section, the cooled synthesis gas is led out of a gasification furnace from the outlet end of an inclined pipe leading-out section, and gas and solid are separated in a descending pipe.

Preferably, in the inclined tube leading-out section, part of ash content carried by the synthesis gas is deposited on the tube wall under the action of gravity, slides to the straight tube section through the inclined tube leading-out section and enters a slag storage area of the gasification furnace; leading out the cooled synthesis gas from the inclined tube leading-out section and discharging the synthesis gas out of the gasifier; the straight pipe section and the inclined pipe leading-out section are both provided with cooling jackets for protecting a down pipe, cooling water in the jacket of the straight pipe section enters from the lower part and is led out from the lower edge of the straight pipe section close to the chilling ring, and cooling water in the jacket of the inclined pipe leading-out section enters from the bottom of the inclined pipe leading-out section and is led out from the top of the inclined pipe leading-out section; the lower end of the cooling jacket of the straight pipe section is more than 0.5 m below the liquid level of the gasification furnace, so that the high-temperature synthesis gas is protected from burning through a downcomer which is not provided with the cooling jacket.

The invention controls the outlet temperature of the synthesis gas by adjusting the flow of the chilling ring chilling water, realizes the adjustment of the temperature of the synthesis gas between 300 and 850 ℃, and the chilling water flow has the minimum value, namely the outlet temperature of the synthesis gas is below 850 ℃; the cooling water in the cooling jacket of the downcomer adopts an independent circulating boiler water system, and the straight pipe section and the inclined pipe leading-out section are respectively provided with flow detection at an inlet and an outlet so as to judge whether the downcomer is burnt through.

Through the high-temperature synthesis gas leading-out structure of the downcomer, the high-temperature synthesis gas (850 ℃) can be led out of the gasification furnace, and downstream heat recovery and comprehensive utilization are facilitated; ash carried in the synthesis gas is not easy to adhere and accumulate at the downstream; the temperature control of the synthesis gas can be realized by adjusting the chilling water flow; the cooling water circulating system is independently sleeved, so that the running condition of the downcomer in the gasification furnace can be visually judged.

Compared with the prior art, the invention has the advantages that: the method adopts a chilling ring to partially chill the high-temperature synthesis gas, the partially chilled synthesis gas recovers heat through a waste pot, the temperature of the synthesis gas entering the waste pot is adjusted by adjusting the chilling water flow of the chilling ring, a descending pipe adopts a jacket mode, the pressure in the jacket is lower than the pressure on the side of the synthesis gas, and an independent cooling circulating water return system is adopted to monitor whether the descending pipe is burnt through during the operation; the pressure of the circulating water separation tank of the cooling jacket of the downcomer is adjustable, the heat capacity of the circulating water is improved by increasing the pressure, and the circulating return water is prevented from being vaporized; the invention is not only suitable for the entrained flow bed coal gasification technology, but also suitable for the oil gasification, gaseous hydrocarbon gasification and other technologies, and is suitable for the downcomer modification of entrained flow bed gasification; compared with a pure chilling process with a lower descending pipe, the sensible heat of the synthesis gas can be almost completely recovered, high-quality steam can be produced as a byproduct, and the heat efficiency is high; compared with the existing waste pot chilling process for synthesis gas, the process is simple, convenient to control, safe and reliable, the occupied area of the device can be reduced, and the device investment is reduced.

Drawings

FIG. 1 is a flow chart of an embodiment of the present invention;

FIG. 2 is a schematic view of a high temperature syngas discharge structure of the downcomer of FIG. 1.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

As shown in fig. 1 and 2, the novel gasification waste boiler process of the embodiment includes a chilling system, a waste heat recovery system and a downcomer protection system, wherein the chilling system includes a gasifier F01, a downcomer, a chilling water pump P01, a chilling water flow regulating valve FV01, a gasifier liquid level control valve LV01 and a gasifier syngas temperature monitoring; the waste heat recovery system comprises a waste boiler E01, a steam pocket V01, a high-pressure deoxygenation water pump P02, a steam pocket pressure control valve PV01 and a steam pocket continuous blowdown flow regulating valve FV 03; the downcomer protection system comprises a downcomer cooling jacket circulating water separation tank V02, a downcomer cooling jacket circulating water cooler E02, a downcomer cooling jacket circulating water pump P03, a supplementary boiler water cut-off valve XV01 and a CO online analyzer, and the specific device is consistent with the following process.

The novel gasification waste boiler process comprises the following steps:

1) chilling system

Firstly, the gasification raw material and the gasification agent enter a reaction chamber of a gasification furnace F01 through a burner A01 to carry out gasification reaction, and the reaction produces the product mainly containing CO and H₂The temperature of the high-temperature synthesis gas is 1500 ℃;

secondly, the high-temperature synthesis gas descends and is cooled by chilling water sprayed by a chilling ring, the molten ash is condensed into solid, and the temperature of the synthesis gas is controlled to 850 ℃ after cooling;

thirdly, the chilled synthetic gas at the temperature of 850 ℃ descends, is separated from ash at a break angle and is discharged out of the gasifier;

fourthly, opening a slag lock hopper feed valve XV02 after the slag in the gasification furnace is stored for a certain time;

2) waste heat recovery system

Firstly, the synthesis gas of-850 ℃ after the gasification furnace F01 is partially chilled enters a waste boiler E01, the synthesis gas is heated by a waste boiler E01 to reach the temperature of-350 ℃, and the synthesis gas is sent to the downstream;

secondly, conveying the deoxygenated water in the steam drum V01 to a waste boiler E01 through a high-pressure deoxygenation water pump P02, and cooling the synthesis gas, wherein the working pressure of the steam drum V01 is-10 MPa;

thirdly, the deoxidized water passing through the waste boiler E01 is partially vaporized to generate high-pressure steam, the steam-water mixed phase is discharged from the waste boiler E01 and enters a steam drum V01 for steam-water separation, and the high-pressure steam is sent to the downstream after passing through a steam drum pressure control valve PV 01;

3) downcomer protection system

Step one, boiler water in a circulating water separation tank V02 of a downcomer cooling jacket is pressurized by a circulating water pump P03 of the downcomer cooling jacket, enters the lower part of the downcomer jacket and goes upward along the downcomer jacket;

secondly, after passing through a descending pipe jacket, the circulating cooling water is heated, is led out from the top of the descending pipe jacket, enters the descending pipe cooling jacket and circulates back to the water cooler E02 and is cooled;

thirdly, the cooled circulating backwater enters a downcomer cooling jacket circulating water separation tank V02;

and fourthly, restarting the first step.

The gasifier outlet synthesis gas is provided with temperature monitoring, and when the outlet synthesis gas temperature fluctuates, the chilling water flow is adjusted by adjusting a chilling water flow adjusting valve FV01 to control the synthesis gas temperature.

The gasifier is provided with liquid level monitoring, and when the liquid level fluctuates, the liquid level of the gasifier is controlled to be stable by adjusting a gasifier liquid level control valve LV 01.

The outlet of the high-pressure deoxygenation water pump P02 is provided with a flow monitor, and the outlet of the waste boiler E01 is provided with a synthetic gas temperature monitor; the temperature control of the synthesis gas at the outlet of the waste boiler E01 is realized by enough heat exchange area and enough flow of deoxygenated water, and the deoxygenated water amount is more than 20 times of the steam yield and is kept constant.

The pressure of the steam drum V01 is regulated by a steam drum pressure control valve PV01, and the pressure of the steam drum is controlled to be higher than the highest operating pressure of the synthesis gas side, so that the synthesis gas does not enter the steam side in a reverse-serial mode when equipment leaks; the steam drum V01 adopts a three-impulse control and regulation system of by-product steam pressure PV01, steam drum liquid level LV02 and continuous blowdown FV 03.

The outlet of a circulating water pump P03 of the cooling jacket of the downcomer is provided with flow monitoring, the outlet of circulating water of the jacket of the downcomer is provided with density monitoring, and the gas phase side of a circulating water separation tank V02 of the cooling jacket of the downcomer is provided with a CO monitor; the flow of circulating water is constant, the flow meets the condition that circulating backwater at the outlet of a descending pipe jacket does not generate vaporization, and whether vaporization occurs or not is monitored and judged by a density meter.

The pressure of the circulating water in the jacket is lower than the lowest operating pressure of the synthesis gas side, and when the descending pipe is burnt through, the synthesis gas leaks to the circulating water side; the pressure of the circulating water separation tank V02 of the cooling jacket of the downcomer is adjustable, and the circulating water is prevented from being vaporized by increasing the pressure to improve the heat capacity of the circulating water through the split-range control of a pressurizing valve PV02 of the circulating water separation tank and a pressure release valve PV03 of the circulating water separation tank.

When the liquid level of the circulating water separation tank V02 of the downcomer cooling jacket is low, boiler water is supplemented by opening a supplementary boiler water cut-off valve XV 01.

A downcomer high-temperature synthesis gas leading-out structure F02 is arranged in the gasifier F01, the structure is arranged in a chilling chamber at the lower part of the gasifier, and the upper end of the structure is connected with a gasifier reaction chamber;

the leading-out structure F02 consists of a straight pipe section 1 and an inclined pipe leading-out section 8, the central line of the inclined pipe leading-out section 8 and the central line of the straight pipe section 1 form an angle alpha, and alpha is less than or equal to 45 degrees, so that ash settled in the synthesis gas is prevented from accumulating and blocking in the pipe; high-temperature synthetic gas containing molten ash from a gasification combustion chamber enters a chilling ring 2 at the top of a straight pipe section through a synthetic gas inlet, the chilling ring 2 continuously sprays chilling water, the high-temperature synthetic gas is fully contacted with the chilling water in the straight pipe section 1, the synthetic gas is cooled to below 850 ℃, the molten ash is cooled and solidified, most of solid ash is output from the lower end of the straight pipe section, the cooled synthetic gas is led out of a gasification furnace from the outlet end of an inclined pipe leading-out section 8, and gas and solid are separated in a descending pipe. An expansion joint 7 is arranged on the inclined tube leading-out section 8.

In the inclined tube leading-out section 8, part of ash content carried by the synthesis gas is deposited on the tube wall under the action of gravity, slides to the straight tube section 1 through the inclined tube leading-out section 8 and enters a slag storage area of the gasification furnace; the cooled synthesis gas is led out from the inclined tube leading-out section 8 and is discharged out of the gasifier; the straight pipe section 1 and the inclined pipe leading-out section 8 are both provided with a cooling jacket 4 for protecting a downcomer.

A cooling water inlet 6 of the cooling jacket 4 is arranged at the lower part of the straight pipe section 1, a chilling water inlet 3 is arranged at the upper end of the straight pipe section 1, and a cooling water outlet 5 is arranged at the upper end of the straight pipe section 1. The straight pipe section jacket cooling water enters from the lower part and is led out from the lower edge of the straight pipe section 1 close to the chilling ring, and the inclined pipe leading-out section 8 jacket cooling water enters from the bottom of the inclined pipe leading-out section 8 and is led out from the top of the inclined pipe leading-out section 8; the lower end of the cooling jacket of the straight pipe section 1 is more than 0.5 m below the liquid level of the gasification furnace, so that the high-temperature synthesis gas is protected from burning through a downcomer which is not provided with the cooling jacket.

In the embodiment, the outlet temperature of the synthesis gas is controlled by adjusting the flow of chilling water of the chilling ring 2, so that the adjustment of the temperature of the synthesis gas between 300 and 850 ℃ is realized, and the chilling water flow has the minimum value, namely the outlet temperature of the synthesis gas is below 850 ℃; the cooling water in the cooling jacket of the downcomer adopts an independent circulating boiler water system, and the straight pipe section and the inclined pipe leading-out section are respectively provided with flow detection at an inlet and an outlet so as to judge whether the downcomer is burnt through.

Through the downcomer high-temperature synthesis gas extraction structure F02, high-temperature synthesis gas (<850 ℃) can be extracted out of the gasifier, and downstream heat recovery and comprehensive utilization are facilitated; ash carried in the synthesis gas is not easy to adhere and accumulate at the downstream; the temperature control of the synthesis gas can be realized by adjusting the chilling water flow; the cooling water circulating system is independently sleeved, so that the running condition of the downcomer in the gasification furnace can be visually judged.

Taking the 10 ten thousand standard of effective gas produced in 1500 ton class hour as an example, the operation parameters of the embodiment are as follows:

note: the volume flow and the mass flow are free of ash.

In the embodiment, a chilling ring is used for partially chilling high-temperature synthesis gas, the partially chilled synthesis gas recovers heat through a waste pot, the temperature of the synthesis gas entering the waste pot is adjusted by adjusting the chilling water flow of the chilling ring, a descending pipe adopts a jacket mode, the pressure in the jacket is lower than the pressure of the synthesis gas side, and an independent cooling circulating water return system is adopted to monitor whether the descending pipe is burnt through in the operation process; the pressure of the circulating water separation tank of the cooling jacket of the downcomer is adjustable, the heat capacity of the circulating water is improved by increasing the pressure, and the circulating return water is prevented from being vaporized; the invention is not only suitable for the entrained flow bed coal gasification technology, but also suitable for the oil gasification, gaseous hydrocarbon gasification and other technologies, and is suitable for the downcomer modification of entrained flow bed gasification; compared with a pure chilling process with a lower descending pipe, the sensible heat of the synthesis gas can be almost completely recovered, high-quality steam can be produced as a byproduct, and the heat efficiency is high; compared with the existing waste pot chilling process for synthesis gas, the process is simple, convenient to control, safe and reliable, the occupied area of the device can be reduced, and the device investment is reduced.