WO2019196497A1

WO2019196497A1 - Synthesis-gas sensible heat recovery apparatus and recovery method, and gasifier

Info

Publication number: WO2019196497A1
Application number: PCT/CN2018/122285
Authority: WO
Inventors: 张燕
Original assignee: 北京迈未科技有限公司
Priority date: 2018-04-09
Filing date: 2018-12-20
Publication date: 2019-10-17
Also published as: CN108342227B; CN108342227A

Abstract

Provided are a synthesis-gas sensible heat recovery apparatus and method, and also provided is a gasifier comprising said sensible heat recovery apparatus; the sensible heat recovery apparatus is provided with multiple stages of spraying apparatuses; by means of a first injection apparatus (61), a low-temperature region near a heat exchange surface and a core high-temperature region located in the middle of the low-temperature region are formed upstream of the radiation heat exchange chamber (3); by means of radiation, heat is exchanged between the core high-temperature region and the heat exchange surface, effectively improving the efficiency of heat exchange. The sensible heat recovery apparatus is also provided with multiple stages of spraying apparatuses; thus a plurality of regions is formed on the flow path of the gasification synthesis gas, thereby controlling the division of regions; in addition, a flow-guiding ash removal structure is provided, improving, by means of guiding the flow, the path of motion of ash particles of different particle sizes in the gas flow, reducing the possibility of large particle ash moving toward the inner cylinder wall, and reducing the entrainment of small particle ash in the synthesis gas.

Description

Syngas sensible heat recovery device and recovery method and gasifier

Technical field

The invention relates to the technical field of coal gasification, in particular to a syngas sensible heat recovery device and method, and a gasification furnace including the same.

Background technique

The gasification technology of carbonaceous raw materials such as fossil fuels such as coal and petroleum coke, biomass fuel such as plant straw, or domestic garbage, the main purpose is to partially convert the chemical energy in the carbonaceous raw materials into the generated gas (generally called synthesis). The chemical energy of the gas is used as a fuel; or the carbonaceous raw material is made into CO and H ₂ as a raw material for the subsequent process. For example, in the incomplete combustion reaction of a carbonaceous fuel and a gasifying agent at a high temperature, most of the carbon and hydrogen in the fuel are converted into a synthesis gas mainly composed of CO and H ₂ , and the chemistry in the carbonaceous raw material in the process. About 80% of the chemical energy can be converted to syngas, and about 20% is converted to the sensible heat of syngas and ash. The technology of recovering about 20% of sensible heat is the sensible heat recovery technology of gasification synthesis gas, which is generally converted into sensible heat or latent heat of water vapor by a heat exchanger method, and further used for power generation and medium. Heating, etc.

The syngas produced by gasification has the characteristics of high temperature and large amount of ash. Especially with the extensive use of coal resources, the coal types suitable for the current gasification technology have become in short supply, and the use of high-carbon resources such as anthracite with higher ash melting point and petroleum coke with low gasification activity is imminent. The gasification conditions of carbonaceous feedstocks are more demanding, such as higher gasification temperatures, thus making the sensible heat recovery unit more stringent. Taking the high-pressure dry powder gas flow bed gasification technology as an example, the temperature of the synthesis gas produced by gasification is generally 1200-1600 ° C, the ash content is 20-200 g/Nm ³ , and the ash residue is molten at high temperature, which is easy to bond. In the heat exchange wall surface, the heat exchange efficiency is greatly reduced. Therefore, the most urgent requirement for the gasification synthesis gas sensible heat recovery device is to reduce the ash and slag on the heating surface and improve the heat exchange efficiency.

For example, in the prior art, U.S. Patent No. 4,377,132 (Synthesis gas cooler and waste heat boiler) discloses an internal and external double cylinder type syngas cooler, which directly vaporizes syngas and ash directly. It enters the inner cylinder of the cooler and folds back into the annular space between the inner cylinder and the outer cylinder to exchange heat with the water wall. However, direct contact of the high temperature gasification syngas with the water wall causes the ash to adhere to the wall surface of the annular space.

In order to alleviate the problem of ash slag bonding, there is a method in the prior art that uses water spray to cool the high temperature syngas. A method for producing synthesis gas is disclosed in Chinese Patent Publication No. CN1923975B. The mixture of synthesis gas and ash in the method first enters a quenching zone, and is quenched to 700-1100 ° C under the action of nozzle water spray, and then The heat is transferred to the waste heat kettle for heat exchange so that the cooled ash does not adhere to the heat exchange surface. In the syngas heat recovery process disclosed in Chinese Patent Document CN101161792A, the first stage chilled water is sprayed at the outlet of the gasification zone, so that the syngas and slag are uniformly and rapidly cooled to below the ash melting point T1, and then enter the fire tube steam. The generator performs heat recovery. Chinese patent document CN102213409A discloses a sensible heat recovery, which is a water spray desuperheating device arranged in the annulus of the inner layer water wall and the outer layer water wall, and when the inner layer water wall heat transfer deteriorates, the water spray reduces the syngas and The ash temperature is used to reduce the ash accumulation of the annulus.

In the above prior art, by cooling and cooling the high-temperature synthesis gas, the ash cooling loses its viscosity, and thus it is not easy to adhere to the heating surface, thereby effectively solving the problem of wall surface slagging. However, the problem with this method is that as the temperature of the syngas is lowered, the radiant heat transfer capacity of the syngas is also greatly reduced. It is known that the heat flux density of the radiant heat transfer is proportional to the fourth power of the gas temperature. Therefore, it is roughly estimated that the gas temperature is lowered from 1500 ° C to 1100 ° C, and the heat flux density of the radiant heat transfer is reduced to 35%. It can be seen that this method has made a great sacrifice in the heat exchange efficiency of the radiation heat exchange chamber in order to cool the ash.

Therefore, how to solve the problem of wall slagging under the premise of reducing the loss of heat exchange efficiency as much as possible is a technical difficulty in the art. In the prior art, Chinese Patent Publication No. CN101821365A discloses a gasification cooling system which circumscribes a gas into a heat exchange passage, so that the high-temperature synthesis gas flows in a ring shape in the annular heat exchange wall, and is controlled by The flow rate, vibration frequency and other parameters of the nozzle fluid make the syngas more evenly distributed in the heat pipe to improve the heat exchange efficiency; at the same time, the acoustic vibration is used to increase the disturbance to enhance the heat exchange. The cooling system in this patent enhances the convective heat transfer on the heat exchange surface by enhancing the flow of the syngas on the heat exchange surface for enhanced heat transfer. But in fact, at high temperatures, the intensity of radiative heat transfer is much higher than that of convection heat, so the heat transfer efficiency of this heat transfer system is very limited. How to further improve the heat exchange efficiency of the syngas is an unsolved problem in the field.

Summary of the invention

The invention solves the problem that the heat exchange efficiency of the existing gasification synthesis gas sensible heat recovery technology, especially the radiation heat exchange efficiency, is low, thereby providing an effective improvement of the radiation heat exchange efficiency and at the same time solving the wall surface slagging. The problem of syngas sensible heat recovery apparatus and method, and the present invention also provides a gasification furnace including the syngas sensible heat recovery apparatus.

The technical solution adopted by the present invention to solve the above technical problems is:

A syngas sensible heat recovery device comprises: a radiation heat exchange chamber, wherein a heat exchange surface is arranged in the radiation heat exchange chamber; a radiation heat exchange chamber inlet is arranged on the radiation heat exchange chamber; a first spraying device is disposed on the upstream portion of the heat exchange surface of the chamber, forming a low temperature region adjacent to the heat exchange surface and a core high temperature region located at a side of the low temperature region away from the heat exchange surface; A radiant heat exchange chamber outlet is disposed downstream of the radiant heat exchange chamber.

The first spraying device is a first nozzle group, and a spray radius of each of the first nozzle groups is greater than 0 and smaller than an equivalent radius of a cylinder surrounded by the heat exchange surface at a position where the nozzle is located; The fluid stream ejected by each of the first nozzle groups converges with a fluid flow ejected from an adjacent nozzle at a first vertical distance from the heat exchange surface where the first nozzle group is located, the first vertical distance being less than the first The spray radius of each nozzle in the nozzle group.

A second injection device is provided at the inlet of the radiant heat exchange chamber or upstream of the inlet.

The radiant heat exchange chamber comprises a casing and an inner cylinder disposed in the casing, the inner wall surface and the outer wall surface of the inner cylinder are heat exchange surfaces, and one side opening of the inner cylinder and a radiation heat exchange chamber inlet In communication, a fluid passage is formed between the outer wall surface of the inner cylinder and the casing, and the fluid in the radiation heat exchange chamber enters the fluid passage from the downstream of the inner cylinder.

The radiant heat exchange chamber includes an inner cylinder and an outer cylinder disposed between the inner cylinder and the casing, the inner wall surface and the outer wall surface of the inner cylinder and the inner wall surface of the outer cylinder are heat exchange surfaces, One side of the inner cylinder is in communication with the inlet of the radiant heat exchange chamber; a fluid passage is formed between the inner cylinder and the outer cylinder, and fluid in the inner cylinder enters the fluid passage from downstream of the inner cylinder.

The first nozzle group is disposed on an inner wall surface upstream of the inner cylinder; a third injection device is further disposed on an inner wall surface downstream of the inner cylinder, and the third injection device is a third nozzle group. The spray radius of each of the nozzles in the third nozzle group is 50% to 90% of the equivalent radius of the inner cylinder at the position where the nozzle is located.

A fourth injection device is disposed on the fluid passage.

An upstream region of the inner cylinder and a downstream region of the fluid passage are connected through a return port, and when the syngas enters the inner cylinder from the inlet of the radiation heat exchange chamber, a low pressure recirculation zone is formed near the return port. A portion of the gas flow of the fluid passage is directed back through the return port to the upstream of the inner cylinder.

The radiation heat exchange chamber inlet is disposed at a top end of the inner cylinder, and a plurality of air outlets are disposed on a bottom wall surface of the inner tube of the radiation heat exchange chamber, and the air flow directions of the plurality of air outlets are all clockwise Or tilt counterclockwise and coincide with the angle between the tangential directions.

A multi-stage annular baffle is disposed on an outer side of the bottom end of the inner tube of the radiant heat exchange chamber, the multi-stage annular baffles are sequentially disposed in an inner-outward direction, and the bottom end of the annular baffle is sequentially in a vertical direction reduce.

A gasification furnace comprising the syngas sensible heat recovery device, further provided with a gasification chamber, a gasification agent and an oxidant inlet are disposed upstream of the gasification chamber, and a downstream of the gasification chamber is disposed There is a gasification chamber outlet; the radiant heat exchange chamber inlet is connected to the gasification chamber outlet.

Based on the sensible heat recovery method of the syngas sensible heat recovery device, the syngas enters the radiant heat exchange chamber for heat exchange, and the temperature of the low temperature region of the radiant heat exchange chamber is lower than 900 ° C, and the core The temperature in the high temperature zone is above 900 ° C; wherein the equivalent radius of the core high temperature zone accounts for 30% to 95% of the equivalent radius of the radiation heat exchange chamber at the location thereof.

The syngas is pre-cooled before entering the radiant heat exchange chamber for heat exchange, so that the temperature of the syngas entering the radiant heat exchange chamber is not higher than 1500 °C.

In the syngas sensible heat recovery device of the present invention, a first spraying device is disposed on a heat exchange surface upstream of the radiant heat exchange chamber to form a low temperature region adjacent to the heat exchange surface and a middle portion located in the low temperature region a core high temperature zone; the first spraying device is preferably configured as a first nozzle group, and each of the first nozzle groups ejects a fluid flow at a first vertical distance d ₁ from a position of the heat exchange surface where it is located The fluid flow ejected from adjacent nozzles converges, the first vertical distance d _{1 being} greater than 0 and less than the equivalent radius R ₁ of the cylinder surrounded by the heat exchange surface at the location of the nozzle, preferably the first vertical distance d ₁ More than 0 and less than 60% of the equivalent radius R ₁ , further preferably the first vertical distance d _{1 is} greater than 0 and less than 30% of the equivalent radius R ₁ ; in this arrangement, the fluid ejected by the dispersed nozzle forms an effective isolation Thereby forming a low temperature zone close to the heat exchange surface. The ash particles entering the low temperature zone lose their viscosity after cooling, and do not form hard slag which is difficult to remove on the wall surface. At the same time, the core high temperature zone still maintains a high temperature above 900 °C, thereby maintaining a high radiation heat exchange capacity. Since the radiation heat exchange amount in the core high temperature region accounts for a large part of the total heat exchange amount of the radiation heat exchange chamber, the method of cooling the core region and the core high temperature in the present invention can effectively increase the amount of heat exchange with respect to the total temperature of the synthesis gas.

The syngas sensible heat recovery device of the present invention is provided with a second injection device at the inlet or upstream of the inlet of the radiant heat exchange chamber. The second spraying device injects a fluid medium into the syngas, and pre-cools the high-temperature syngas and ash, so that the temperature of the gasification syngas entering the radiant heat exchange chamber is not higher than 1500 ° C, and the temperature is too high. The radiant heat exchange chamber material is overheated, and the second spraying device is preferably a second nozzle group. The second nozzle group may be disposed at an inlet of the radiant heat exchange chamber, or may be disposed upstream of the inlet, that is, a throat passage between the gasification chamber and the inlet of the radiant heat exchange chamber .

Preferably, the radiant heat exchange chamber includes an inner cylinder disposed in the housing, and the inner cylinder is provided with a radiant heat exchange chamber inlet, and a fluid is formed between the outer wall surface of the inner cylinder and the outer casing or the outer cylinder A passage in which fluid in the radiant heat exchange chamber enters the fluid passage from downstream of the inner cylinder. In this arrangement, a third injection device is also disposed inside the bottom of the inner cylinder. The third spraying device is preferably a third nozzle group, and each of the third nozzle groups has a spray radius of 50% R to 90% R, wherein R is an equivalent radius of the inner cylinder at the position where the nozzle is located, In the setting mode, the third spraying device has a large penetration depth, can effectively reduce the temperature of the syngas center, and efficiently realize the overall cooling of the syngas and ash in the cross section, because the heat transfer in the cylinder is completed in this position. Most of the time, the syngas is about to turn into the annular space, thus reducing the temperature in the core region of the gas stream, and effectively preventing the molten ash particles in the core high temperature region from sticking to the wall surface during turning.

In the syngas sensible heat recovery device of the present invention, a fourth spraying device is further disposed on the fluid passage, and the inner side of the lower portion of the outer cylinder is a position where the ash particles collide in a concentrated manner after the gas is bucked, and the region is cooled. The insufficiently cooled ash particles are further cooled prior to impacting the wall to reduce or prevent adhesion.

The first nozzle group, the second nozzle group, the third nozzle group and the fourth nozzle group, each of the nozzle groups may be arranged in multiple layers or in a single layer, and the nozzles in each layer may be uniformly arranged or unevenly arranged; The plurality of nozzles and the nozzles of the respective layers may be arranged in a staggered or non-staggered manner, and the ejection direction of each nozzle is preferably a central horizontal jet, a circumferential jet, or an oblique jet. In addition to the nozzle group, the first injection device, the second injection device, the third injection device, and the fourth injection device may employ other injection devices, such as an annular injection device having a continuous annular injection port.

The syngas sensible heat recovery device and method of the present invention have the advantages of:

(1) The syngas sensible heat recovery device according to the present invention, by providing the first ejecting device, forming a low temperature region close to the heat exchange surface and a core high temperature region located in the middle of the low temperature region upstream of the radiation heat exchange chamber, The radiation heat exchange mode between the core high temperature zone and the heat exchange surface effectively improves the efficiency of heat exchange. At the same time, the sensible heat recovery device of the present invention realizes the zone control by providing a multi-stage injection device to form a plurality of regions on the flow path of the gasification synthesis gas.

(2) The syngas sensible heat recovery device of the present invention is provided with an air flow outlet and a multi-stage annular baffle, wherein a plurality of the air flow outlets are disposed around a bottom wall surface of the inner tube of the radiation heat exchange chamber, After the fluid reaches the bottom, the particles in the inclusion continue to move downward under the action of inertia, and part of the airflow diffuses to the outside through the outlet of the airflow, and further splits under the action of the multi-stage annular baffle to realize gas-solid two The phase flow reduces the movement of the large particles toward the inner cylinder wall by adopting the diversion ash removal technology, and reduces the small particles entrained in the airflow in the airflow turning region.

(3) The syngas sensible heat recovery device according to the present invention, wherein a inlet of the radiant heat exchange chamber is provided with a return port, and a low pressure recirculation zone is formed near the return port, and a part of the gas flow is ignited Refluxing to the radiant heat exchange chamber optimizes the inlet gas flow recirculation of the radiant heat exchange chamber, increases the heat exchange time of the gas flow in the heat exchange chamber, and enhances the heat exchange effect.

In order to make the synthetic gas sensible heat recovery device and the recovery method and the gasification furnace of the present invention more clear, the technical solutions in the present invention will be further described below in conjunction with the specific embodiments and the accompanying drawings.

DRAWINGS

1 is a schematic structural view of a heat exchange device provided with a return passage at the top end of the inner cylinder according to the present invention;

2 is a schematic structural view showing a cross section of an inner cylinder of a radiation heat exchange chamber according to the present invention;

3 is a schematic structural view showing a cross section of a throat passage of the heat exchange device according to the present invention;

4 is a schematic structural view showing a changeable manner of the heat exchange device according to the present invention;

Figure 5 is a schematic view showing the structure of the multi-stage annular baffle according to the present invention;

Figure 6 is a schematic view showing the structure of the bottom of the inner cylinder provided with a plurality of air outlets according to the present invention;

Fig. 7 is a cross-sectional plan view showing a plurality of air outlets according to the present invention.

detailed description

In the following, only certain exemplary embodiments are briefly described. The described embodiments may be modified in various different ways, without departing from the spirit and scope of the invention. Accordingly, the drawings and description are to be regarded as illustrative rather

In the following embodiments, the terms "upstream" and "downstream" when describing the orientation are relative to the flow direction of the fluid; the "top" and "bottom" involved are relative to the vertical placement of the device. The upper end in the vertically placed state is the top end, and the bottom end is the bottom end; the "inner" and "outer" are directed to the outside of the gasifier by the internal intermediate position of the device with respect to the inside and outside of the device. The "spray radius" of the nozzle referred to herein means that the flow velocity of the fluid ejected from the nozzle is attenuated to 90% of the discharge flow rate or the proportion of the fluid phase change is 90% of the discharge fluid flow rate. The position of % is the vertical distance from the injection port. It should be noted that the gasifier or the sensible heat recovery device in the present invention can also be placed in a non-vertical manner, and the present invention can still achieve the technical effects when it is disposed in a lateral or inclined manner.

Example 1

As shown in FIG. 1, the gasification furnace described in the present embodiment includes a casing 1 in which a gasification chamber is disposed, and a gasification agent is disposed upstream of the top end of the gasification chamber. With the oxidant inlet 21, a gasification chamber outlet 22 is provided downstream of the bottom end of the gasification chamber.

a radiation heat exchange chamber 3 comprising an inner cylinder 32 and an outer cylinder 33 disposed in the casing; the radiation heat exchange chamber 3 described in the embodiment is disposed below the gasification chamber 2, The inner side and outer side wall surfaces of the inner cylinder 32 and the inner side wall surface of the outer cylinder 33 are heat exchange surfaces. The inner cylinder 32 and the outer cylinder 33 in the present embodiment are both cylindrical cylinders. As an alternative embodiment, the inner cylinder 32 and the outer cylinder 33 may also be arranged in a square or other arbitrary shape. body. A radiation heat exchange chamber inlet 31 is disposed at a top end of the inner cylinder 32, and the radiation heat exchange chamber inlet 31 is disposed in communication with the outlet of the gasification chamber 2; and is disposed on a heat exchange surface upstream of the inner cylinder 32 The first spraying device has a low temperature region adjacent to the heat exchange surface and a core high temperature region located on the inner side of the low temperature region away from the heat exchange surface, because the heat exchange surface of the inner cylinder is a tube in the embodiment. The body thus forms a core high temperature zone located in the middle of the barrel. The first spraying device 61 is preferably a first nozzle group, the first nozzle group is disposed around a circumference of the heat exchange surface upstream of the inner cylinder 32, and may be provided with multiple layers or a single layer in the fluid flow direction. The fluid flow direction in the embodiment is from top to bottom. In the embodiment, the first nozzle group is provided with three layers, and the adjacent two layer nozzles are arranged in a staggered manner. As shown in FIG. 2, a plurality of nozzles in each layer of nozzles are evenly arranged, and each nozzle of each layer is sprayed. The radius d _{1 is} greater than 0 and less than the equivalent radius of the inner cylinder 32 where the nozzle is located. As a preferred embodiment, the spray radius d _{1 of} each nozzle is greater than 0 and less than 60% of the equivalent radius of the inner cylinder 32 where the nozzle is located. More preferably, the spray radius d _{1 of} each nozzle is greater than 0 and less than 30% of the equivalent radius of the inner cylinder 32 where the nozzle is located, thereby facilitating the increase of the volume of the core high temperature zone; out of the fluid flow stream convergence at _a distance d which they are in the same layer and adjacent to the heat transfer fluid nozzle surface position of the first vertical distance, the vertical distance d ₁ is greater than 0 and less than the first ejection nozzle radius Rs ₁ . As an alternative embodiment, the nozzles between the layers may also adopt a non-staggered arrangement; a plurality of nozzles in each layer of nozzles may also adopt a non-uniform arrangement, and the nozzles between the layers are ejected. The fluid streams can converge or not converge.

The radiant heat exchange chamber inlet 31 in the present embodiment is connected to the gasification chamber outlet 22 of the gasification chamber 2 through a throat passage at the inlet of the radiant heat exchange chamber or the throat passage upstream of the inlet Provided with a second spraying device, preferably a second nozzle group, as shown in Figure 2, wherein the spray radius rs ₂ of the nozzle in the second nozzle group is greater than 50 of the radius at the throat passage % (ie 50% R ₂ ) is smaller than the radius R ₂ at the throat passage, the second nozzle group may be provided with a single layer or multiple layers, and the fluid flow ejected from each nozzle of each layer nozzle is at a distance The second vertical distance d ₂ of the heat exchange surface converges with the fluid flow ejected from adjacent nozzles located in the same layer, the distance d _{2 being} smaller than the spray radius of the nozzle. Thereby, the cooling of the overall section is achieved. The second nozzle group is evenly arranged along the circumferential direction of the throat passage.

In the present embodiment, a fluid passage is formed between the inner cylinder 32 and the outer cylinder 33, and the fluid enters the fluid passage from the downstream of the inner cylinder 32, that is, the bottom of the inner cylinder 32. A third spraying device is further disposed on an inner wall surface of the inner cylinder 32 downstream of the first spraying device 61, the third spraying device is a third nozzle group, and each of the third nozzle groups The spray radius is 50% R to 90% R, where R is the equivalent radius of the inner cylinder 32 at the location of the nozzle. A fourth spraying device is further disposed on the fluid passage, and the fourth spraying device is preferably a fourth nozzle group, and the fourth nozzle group is distributed on an outer wall surface of the inner cylinder 32 or a corresponding outer cylinder The fourth nozzle group is disposed near the bottom ends of the inner cylinder 32 and the outer cylinder 33 on the inner wall surface 33; the radiation heat exchange chamber outlet 5 is disposed on the outer cylinder 33 located downstream of the fourth nozzle group.

As a preferred embodiment, a slag pool 4 is provided at a lower portion of the radiant heat exchange chamber, the bottom end of the outer cylinder extending below the liquid level of the slag pool 4, and the bottom end of the inner cylinder being located above the slag pool 4.

In the present embodiment, the region of the inner cylinder 32 located upstream of the first injection device 61 and the region of the fluid passage downstream of the fourth injection device group are connected through the return port 71, as shown in FIG. In the present embodiment, the diameter of the inner cylinder 32 is larger than the throat passage, so that the return port 71 is formed between the inner cylinder 32 and the throat passage. When the syngas enters the radiant heat exchange chamber 3 from the radiant heat exchange chamber inlet 31, a low pressure recirculation zone is formed in the vicinity of the return port 71, and a part of the gas flow of the fluid passage is fluoresced back to the radiant heat exchange Room 3. As an alternative embodiment, the return port 71 may not be provided, and the fluid entering the fluid passage is all discharged through the outlet of the radiant heat exchange chamber, as shown in FIG.

In addition to the nozzle group, the first injection device 61, the second injection device 62, the third injection device, and the fourth injection device may employ other injection devices, such as an annular injection device having a continuous annular injection port.

The recovery method of the syngas sensible heat recovery device according to the embodiment includes: introducing a gasifying agent and an oxidant from the gasifying agent and the oxidant inlet 21 into the gasification chamber 2 for gasification reaction to generate a synthesis gas, wherein the gasification agent a carbonaceous fuel, the oxidant is an oxygen-containing gas and steam; the syngas enters the inner cylinder 32 of the radiant heat exchange chamber 3 from the throat passage, and the second nozzle group ejects fluid during the entering process. Pre-cooling, controlling the temperature of the fluid entering the inner cylinder 32 of the radiation heat exchange chamber 3 is not higher than 1500 ° C; the syngas enters the inner cylinder 32, and the fluid is sprayed by the first injection device 61 to maintain the radiation heat exchange chamber The temperature in the low temperature zone of 3 is lower than 900 ° C, and the temperature in the core high temperature zone is above 900 ° C, thereby ensuring efficient heat exchange efficiency. Wherein the equivalent radius of the core high temperature zone accounts for 30% to 95%, and more preferably 30 to 60%, of the equivalent radius of the radiation heat exchange chamber at the position where it is located. The fluid continuing downward from the low temperature zone and the core high temperature zone is cooled by the further injection of the third injection device, thereby reducing the overall fluid section temperature, thereby reducing the viscosity and preventing the particles from turning into the outer cylinder 33 by the inner cylinder 32. When it collides with the wall surface, after entering between the inner cylinder 32 and the outer cylinder 33, the fourth nozzle group is further sprayed to cool down, so that the insufficiently cooled ash particles are further cooled before colliding with the wall surface, Reduce or prevent sticking.

The fluid discharged from the first nozzle group, the second nozzle group, the third nozzle group, and the fourth nozzle group in the present embodiment is preferably any one or more of nitrogen gas, carbon dioxide, cooled syngas, water vapor, and water. Combination of species.

Example 2

The gasification furnace according to the present embodiment includes a casing 1 in which a vaporization chamber 2 is disposed, and a gasification agent and an oxidant inlet are provided upstream of a tip end of the gasification chamber 2, A gasification chamber outlet 22 is provided downstream of the bottom end of the gasification chamber 2.

A syngas sensible heat recovery device is disposed in the casing 1, the syngas sensible heat recovery device comprising: a radiant heat exchange chamber 3, the radiant heat exchange chamber 3 including a casing 1 and being disposed inside the casing 1 The inner wall surface and the outer wall surface of the inner cylinder 32 are heat exchange surfaces; the radiation heat exchange chamber 3 described in the present embodiment is disposed below the gasification chamber 2, as described in the embodiment. The heat exchange surface is a heat exchange surface composed of a water-cooled tube. As an alternative embodiment, other forms of heat exchange surfaces may also be used. The inner cylinder 32 and the casing 1 of the radiant heat exchange chamber 3 in the present embodiment are both cylindrical cylinders. As an alternative embodiment, the radiant heat exchange chamber 3 may also be arranged in a square or other cross section. Any shape of the cylinder. a radiation heat exchange chamber inlet 31 is disposed at a top end of the inner cylinder, and the radiation heat exchange chamber inlet 31 is disposed in communication with the gasification chamber outlet 22; and a heat exchange surface upstream of the inner cylinder is provided with a first A spray device 61 forms a low temperature zone proximate the heat exchange surface and a core high temperature zone located intermediate the low temperature zone. The first spraying device 61 is preferably a first nozzle group, the first nozzle group is disposed around a circumference of the heat exchange surface upstream of the inner cylinder 32, and may be provided with multiple layers or a single layer in the fluid flow direction. The fluid flow direction in the embodiment is from top to bottom. In the embodiment, the first nozzle group is provided with three layers, the adjacent two layers of nozzles are arranged in a staggered manner, and a plurality of nozzles in each layer of nozzles are evenly arranged, and each of the nozzles in each layer has a jet radius d ₁ greater than 0 and An equivalent radius smaller than the inner cylinder 32 where the nozzle is located. As a preferred embodiment, the spray radius d _{1 of} each nozzle is greater than 0 and less than 60% of the equivalent radius of the inner cylinder 32 where the nozzle is located, and more preferably, The spray radius d _{1 of} each nozzle is greater than 0 and less than 30% of the equivalent radius of the inner cylinder 32 where the nozzle is located; the fluid flow ejected from each nozzle in each nozzle is at a first vertical distance from the heat exchange surface where it is located ₁ d at the same layer and adjacent nozzles converge fluid flow, the first vertical distance d ₁ is greater than 0 and less than the radius of the injection nozzle rs _1.

The radiant heat exchange chamber inlet 31 in the present embodiment is connected to the gasification chamber outlet 22 of the gasification chamber 2 through a throat passage at the inlet of the radiant heat exchange chamber or the throat passage upstream of the inlet Provided with a second injection device 62, preferably a second nozzle group, wherein the nozzle radius rs ₂ of the nozzles in the second nozzle group is greater than 50% of the radius at the throat passage (ie 50 %R ₂ ) is smaller than the radius R ₂ at the throat passage, and the second nozzle group may be provided with a single layer or a plurality of layers, and the fluid flow ejected from each nozzle of each layer nozzle is at a heat exchange surface from the same The second vertical distance d ₂ converges with the fluid flow ejected from adjacent nozzles located in the same layer, the distance d _{2 being} smaller than the spray radius of the nozzle

In the present embodiment, a fluid passage is formed between the outer wall surface of the inner cylinder 32 and the casing 1, and the fluid enters the fluid passage from the downstream of the inner cylinder 32, that is, the bottom of the inner cylinder 32. A third spraying device is further disposed on an inner wall surface of the inner cylinder 32 downstream of the first spraying device 61, the third spraying device is a third nozzle group, and each of the third nozzle groups The spray radius is 50% R to 90% R, where R is the equivalent radius of the inner cylinder at the location of the nozzle. A fourth spraying device is further disposed on the fluid passage, and the fourth spraying device is preferably a fourth nozzle group, and the fourth nozzle group is distributed on an outer wall surface of the inner cylinder and the corresponding casing 1 The inner wall surface is disposed adjacent to the bottom end of the radiant heat exchange chamber 3; and the radiant heat exchange chamber outlet 5 is disposed on the casing 1 located downstream of the fourth nozzle group.

A slag pool 4 is disposed at a lower portion of the radiant heat exchange chamber, and a bottom end of the inner cylinder 32 is located above the slag pool 4. As an alternative embodiment, the bottom end of the inner cylinder 32 may also extend to the slag. Below the liquid level of the pool.

In a most preferred embodiment, the region of the inner cylinder 32 located upstream of the first injection device 61 and the region of the fluid passage downstream of the fourth injection device group are communicated through the return port 71, and the syngas is disposed. When the radiant heat exchange chamber inlet 31 enters the radiant heat exchange chamber, a low pressure recirculation zone is formed near the return port 71, and part of the gas flow of the fluid passage is directed back to the inner cylinder 32 through the return port.

The recovery method of the syngas sensible heat recovery device according to the embodiment includes: introducing a gasifying agent and an oxidant from the gasifying agent and the oxidant inlet 21 into the gasification chamber 2 for gasification reaction to generate a synthesis gas, wherein the gasification agent a carbonaceous fuel, the oxidant is an oxygen-containing gas and steam; the syngas enters the radiant heat exchange chamber 3 through the throat passage, and in the process, the second nozzle group is used to eject the fluid for pre-cooling, Controlling the temperature of the fluid entering the radiation heat exchange chamber 3 is not higher than 1500 ° C; the synthesis gas enters the radiation heat exchange chamber 3, and the fluid is sprayed by the first injection device 61 to maintain the low temperature of the radiation heat exchange chamber 3. The temperature in the zone is below 900 ° C and the temperature in the core high zone is above 900 ° C. Wherein the equivalent radius of the core high temperature zone accounts for 30% to 95%, and more preferably 30 to 60%, of the equivalent radius of the radiation heat exchange chamber at the position where it is located. The fluid discharged from the first nozzle group, the second nozzle group, the third nozzle group, and the fourth nozzle group in the present embodiment is preferably any one or more of nitrogen gas, carbon dioxide, cooled syngas, water vapor, and water. Combination of species.

Example 3

The gasification furnace according to the present embodiment includes a casing 1 in which a gasification chamber 2 is disposed, and a gasification agent and an oxidant inlet 21 are disposed upstream of the gasification chamber 2, A gasification chamber outlet 22 is provided downstream of the gasification chamber 2.

A syngas sensible heat recovery device is disposed in the casing 1, the syngas sensible heat recovery device comprising: a radiant heat exchange chamber 3, the radiant heat exchange chamber 3 including a casing 1 and being disposed inside the casing 1 The inner wall surface and the outer wall surface of the inner cylinder 32 are heat exchange surfaces; the radiation heat exchange chamber 3 described in the present embodiment is disposed below the gasification chamber 2, as described in the present embodiment. The inner cylinder 32 and the casing of the radiant heat exchange chamber 3 are both cylindrical cylinders. As an alternative embodiment, the inner cylinder 32 can also be provided as a cylinder having a square or other arbitrary shape in cross section. A radiation heat exchange chamber inlet 31 is disposed at a top end of the inner cylinder 32, and the radiation heat exchange chamber inlet 31 is disposed in communication with the gasification chamber outlet 22; on a heat exchange surface upstream of the inner cylinder 32 A first spraying device 61 is provided to form a low temperature zone proximate the heat exchange surface and a core high temperature zone located intermediate the low temperature zone. The first spraying device 61 is preferably a first nozzle group, the first nozzle group is disposed around a circumference of the heat exchange surface upstream of the inner cylinder 32, and may be provided with multiple layers or a single layer in the fluid flow direction. The fluid flow direction in the embodiment is from top to bottom. In the embodiment, the first nozzle group is provided with three layers, the adjacent two layers of nozzles are arranged in a staggered manner, and a plurality of nozzles in each layer of nozzles are evenly arranged, and each of the nozzles in each layer has a jet radius d ₁ greater than 0 and An equivalent radius smaller than the inner cylinder 32 where the nozzle is located. As a preferred embodiment, the spray radius d _{1 of} each nozzle is greater than 0 and less than 60% of the equivalent radius of the inner cylinder 32 where the nozzle is located, and more preferably, The spray radius d _{1 of} each nozzle is greater than 0 and less than 30% of the equivalent radius of the inner cylinder 32 where the nozzle is located; the fluid flow ejected from each nozzle in each nozzle is at a first vertical distance from the heat exchange surface where it is located ₁ d at the same layer and adjacent nozzles converge fluid flow, the first vertical distance d ₁ is greater than 0 and less than the radius of the injection nozzle rs _1.

The radiant heat exchange chamber inlet 31 in the present embodiment is connected to the gasification chamber outlet 22 of the gasification chamber through a throat passage at the inlet of the radiant heat exchange chamber 3 or the throat passage upstream of the inlet Provided with a second injection device 62, preferably a second nozzle group, wherein the nozzle radius rs ₂ of the nozzles in the second nozzle group is greater than 50% of the radius at the throat passage (ie 50 %R ₂ ) is smaller than the radius R ₂ at the throat passage, and the second nozzle group may be provided with a single layer or a plurality of layers, and the fluid flow ejected from each nozzle of each layer nozzle is at a heat exchange surface from the same The second vertical distance d ₂ converges with the fluid flow ejected from adjacent nozzles located in the same layer, the distance d _{2 being} smaller than the spray radius of the nozzle

In the present embodiment, a fluid passage is formed between the outer wall surface of the inner cylinder 32 and the casing 1, and the fluid enters the fluid passage from the downstream of the inner cylinder 32, that is, the bottom of the inner cylinder 32. A third spraying device is further disposed on an inner wall surface of the inner cylinder 32 downstream of the first spraying device 61, the third spraying device is a third nozzle group, and each of the third nozzle groups The spray radius is 50% R to 90% R, where R is the equivalent radius of the inner cylinder at the location of the nozzle.

The fluid discharged from the first nozzle group, the second nozzle group, and the third nozzle group in the present embodiment is preferably a combination of any one or more of nitrogen gas, carbon dioxide, cooled synthesis gas, water vapor, and water.

In the present embodiment, the region of the inner cylinder 32 located upstream of the first injection device 61 is in communication with the fluid passage through the return port 71, and the syngas enters the radiation exchange from the radiation heat exchange chamber inlet 31. In the case of the hot chamber, a low pressure recirculation zone is formed near the return port 71, and part of the gas flow of the fluid passage is directed back to the inner cylinder 32.

In this embodiment, a plurality of airflow outlets 82 are disposed on the bottom wall surface of the inner cylinder. As shown in FIGS. 6 and 7, the airflow directions of the plurality of airflow outlets 82 are inclined toward the clockwise direction and between the tangential directions. The angles are identical, and the angle can be arbitrarily selected from 0 to 90, preferably from 10 to 60. A multi-stage 71 annular baffle 81 is disposed on an outer side of the bottom end of the inner tube of the radiant heat exchange chamber. As shown in FIG. 5, the multi-stage annular baffle 81 is sequentially disposed in an inner-outward direction, and the annular baffle is disposed. The bottom end of 81 is sequentially lowered in the vertical direction.

The method for recovering the syngas sensible heat recovery device according to the present embodiment includes: feeding a gasifying agent and an oxidizing agent from the gasifying agent and the oxidizing agent inlet 21 to a gasification chamber for gasification reaction to generate a syngas; the syngas is a throat passage enters the radiation heat exchange chamber, wherein the second nozzle group injects fluid to perform pre-cooling, and controls a temperature of the fluid entering the radiation heat exchange chamber to be no higher than 1500 ° C; the syngas enters the The radiation heat exchange chamber sprays the fluid by the first spraying device 61, keeping the temperature of the low temperature region of the radiation heat exchange chamber lower than 900 ° C, and the temperature of the core high temperature region at 900 ° C or higher. Wherein the equivalent radius of the core high temperature zone accounts for 30% to 95% of the equivalent radius of the radiant heat exchange chamber at the location thereof. The fluid continuously descending from the low temperature zone and the core high temperature zone is cooled by the further injection of the third injection device, thereby reducing the overall cross-sectional temperature of the fluid, thereby reducing the viscosity and preventing the particles from turning into the outer side from the inner cylinder and the wall surface. Collision bonding occurs, after the fluid reaches the bottom, the particles in the inclusion continue to move downward under the action of inertia, and part of the airflow diffuses to the outside through the air outlet, and is further shunted by the multi-stage annular baffle. Thereby, the gas-solid two-phase flow is realized, and the movement of the large particles toward the inner cylinder wall surface is reduced by using the flow guiding ash removing technology, and the small particles entrained in the airflow in the airflow turning region are reduced, thereby effectively alleviating the problem of scaling of the heat exchange surface corresponding to the fluid passage. .

In the case where the heat exchange surfaces are arranged exactly the same, the syngas sensible heat recovery device described in the above embodiments 1-3 can increase the heat recovery rate by 10-50 compared to the heat recovery device using the overall water spray cooling mode. %.

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

A synthesizing sensible heat recovery device, comprising: a radiation heat exchange chamber, wherein a heat exchange surface is disposed in the radiation heat exchange chamber; and a radiation heat exchange chamber inlet is disposed on the radiation heat exchange chamber; a first spraying device is disposed on the upstream portion of the heat exchange surface in the radiant heat exchange chamber, forming a low temperature region adjacent to the heat exchange surface and a core high temperature located at a side of the low temperature region away from the heat exchange surface a region; a radiant heat exchange chamber outlet is disposed downstream of the radiant heat exchange chamber.
The syngas sensible heat recovery device according to claim 1, wherein the first injection device is a first nozzle group, and each of the first nozzle groups has a spray radius greater than 0 and smaller than the nozzle. An equivalent radius of the cylinder surrounded by the heat exchange surface; a fluid flow ejected from each nozzle in the first nozzle group at a first vertical distance from the heat exchange surface where it is located and an adjacent nozzle The ejected fluid stream converges, the first vertical distance being less than the jet radius of each of the first nozzle groups.
The syngas sensible heat recovery apparatus according to claim 2, wherein a second injection means is provided at an inlet of the radiant heat exchange chamber or upstream of the inlet.
The synthesizing sensible heat recovery apparatus according to claim 1 or 2 or 3, wherein said radiant heat exchange chamber comprises a casing and an inner cylinder provided in said casing, an inner wall surface of said inner cylinder and The outer wall surface is a heat exchange surface, and one side opening of the inner cylinder communicates with the inlet of the radiation heat exchange chamber, a fluid passage is formed between the outer wall surface of the inner cylinder and the casing, and the fluid in the radiation heat exchange chamber is The downstream of the inner cylinder enters the fluid passage.
The synthesizing sensible heat recovery apparatus according to claim 1 or 2 or 3, wherein said radiant heat exchange chamber comprises an inner cylinder and an outer cylinder disposed between said inner cylinder and said casing, said inner The inner wall surface and the outer wall surface of the cylinder and the inner wall surface of the outer cylinder are heat exchange surfaces, one side of the inner cylinder is in communication with the inlet of the radiation heat exchange chamber; a fluid passage is formed between the inner cylinder and the outer cylinder. Fluid within the inner barrel enters the fluid passage from downstream of the inner barrel.
A syngas sensible heat recovery apparatus according to claim 4 or 5, wherein said first nozzle group is disposed on an inner wall surface upstream of said inner cylinder; and an inner wall surface downstream of said inner cylinder There is further provided a third spraying device, wherein the third spraying device is a third nozzle group, and a spray radius of each of the third nozzle groups is 50% to 90% of an equivalent radius of the inner cylinder at a position where the nozzle is located. .
A syngas sensible heat recovery apparatus according to claim 6, wherein a fourth injection means is provided on said fluid passage.
The syngas sensible heat recovery apparatus according to claim 6, wherein an upstream region of the inner cylinder and a downstream region of the fluid passage are connected through a return port, and the syngas enters from the inlet of the radiation heat exchange chamber. In the inner cylinder, a low pressure recirculation zone is formed in the vicinity of the return port, and a part of the gas flow of the fluid passage is led back through the return port to the upstream of the inner cylinder.
A syngas sensible heat recovery apparatus according to any one of claims 1-8, wherein said radiant heat exchange chamber inlet is provided at a top end of said inner cylinder, and at a bottom side of said inner tube of said radiant heat exchange chamber A plurality of airflow outlets are disposed on the wall surface, and the airflow directions of the plurality of airflow outlets are inclined toward a clockwise or counterclockwise direction and coincide with an angle between the tangential directions.
The synthesizing sensible heat recovery device according to claim 9, wherein a multi-stage annular baffle is disposed outside the bottom end of the inner tube of the radiant heat exchange chamber, and the multi-stage annular baffle is located from the inside to the outside The directions are sequentially set, and the bottom ends of the annular baffles are sequentially lowered in the vertical direction.
A gasification furnace comprising the syngas sensible heat recovery device according to any one of claims 1 to 10, characterized in that a gasification chamber is further provided, and a gasification agent and an oxidant inlet are arranged upstream of the gasification chamber, A gasification chamber outlet is disposed downstream of the gasification chamber; the radiation heat exchange chamber inlet is disposed in communication with the gasification chamber outlet.
The sensible heat recovery method of the syngas sensible heat recovery device according to any one of claims 1 to 10, characterized in that the syngas enters the radiant heat exchange chamber for heat exchange, and the low temperature of the radiant heat exchange chamber The temperature of the zone is lower than 900 ° C, and the temperature of the core high temperature zone is above 900 ° C; wherein the equivalent radius of the core high temperature zone accounts for 30% to 95% of the equivalent radius of the radiation heat exchange chamber at the location thereof.
The sensible heat recovery method according to claim 12, wherein the syngas is subjected to pre-cooling treatment to enter the syngas of the radiant heat exchange chamber before entering the radiant heat exchange chamber for heat exchange. The temperature is not higher than 1500 °C.