A system for recovering and purifying raw coal gas containing high-concentration coke powder particles

Abstract

The present application discloses a high-concentration coke powder particle coal gas energy recovery and purification system, including: an evaporator section, a superheating section, an evaporator section 2, a cyclone separator, a high-efficiency dust collector and a coal economizer. The evaporator section, the superheating section and the evaporator section 2 are connected in upper, middle and lower positions in sequence to form a waste heat boiler; the outlet of the evaporator section 2 is connected to the cyclone separator through a pipeline, and the coal gas after centrifugal separation by the cyclone separator passes through the evaporator section 2 and enters the high-efficiency dust collector and the coal economizer; the setting positions of the high-efficiency dust collector and the coal economizer are interchangeable. The present application solves the problems of wear, corrosion and blockage of the heat exchange tubes in the low-temperature section during the coal gas cooling process, greatly prolongs the service life of the waste heat boiler and the coal economizer, and is suitable for cooling and purifying high-temperature raw coal gas produced in the fluidized bed gasification field and the fluidized bed gasification field.

Description

Technical Field

[0001] The present application belongs to the technical field of heat recovery and purification of high-temperature dusty coal gas, and specifically relates to an energy recovery and purification system for raw coal gas containing high-concentration coke powder particles. Background Art

[0002] my country's energy structure is more coal and less oil. Therefore, using coal as raw material to produce chemical products is of vital importance to reduce the country's dependence on oil and improve energy security. Coal-to-gas is an important technical support for the realization of coal-based chemical industry. At present, coal-to-gas mainly uses fluidized bed gasifiers and entrained flow gasifiers. It must be dusted and cooled to recover energy to obtain clean low-temperature coal gas before it can enter the downstream process for transformation or desulfurization and decarbonization to produce qualified purified coal gas.

[0003] For cooling and purification of high-temperature raw coal gas rich in high-concentration dust, the fluidized bed gasifier is divided into a coal gas upward waste heat boiler cooling process and a coal gas downward quenching cooling process; due to the limitation of the gasification principle, the fluidized bed gasifier only has a coal gas upward waste heat boiler process.

[0004] The existing upward waste heat boiler process of the entrained flow gasifier mostly adopts circulating gas quenching plus coil-type and straight-tube water-cooled wall waste heat boiler, and sends it to the ceramic dry dust collector after cooling to 340℃. This process configuration often causes the waste heat boiler to be blocked due to the large amount of molten slag and coke powder entrained into the coil-type and straight-tube water-cooled wall waste heat boiler, affecting the heat exchange effect.

[0005] The existing fluidized bed gasifier upward waste heat boiler cooling process generally first passes through a high-temperature cyclone dust collector to perform initial dust removal on the high-temperature coal gas at 850-1050°C. The high-temperature coal gas after cyclone dust removal is sent to the air preheater and waste heat boiler to cool down to 165-280°C. The dust concentration of this coal gas is still as high as 30-150g / Nm 3 After the waste heat boiler is cooled, the coal gas is sent to the downstream conversion or desulfurization and decarbonization section after dry dust removal and water washing. Since the high-temperature coal gas entering the waste heat boiler contains high levels of coal ash and coke powder (30-150g / Nm 3 ), these coal ash and coke powder particles quickly scour the fire tubes and shell parts of the evaporation section, superheating section and economizer section of the waste heat boiler, causing wear of the above parts and causing the heat exchange tubes to rupture; in addition, as the coal gas passes through the waste heat boiler, the temperature continues to decrease, the gas velocity of the coal gas gradually decreases, and the coke powder particles in the coal gas tend to be deposited on the surface of the heat exchanger; especially in the water tube economizer section, since the water tube wall temperature is close to the coal gas dew point, some dead zones have dew point corrosion, the water tube surface is corroded and becomes rough, and it is easier to adhere to the coal ash and coke powder in the coal gas. Over time, large pieces of dirt form on the water tube shell, which further causes under-scale corrosion. In more serious cases, it may cause the waste heat boiler to be shut down for overhaul.

[0006] In the prior art, the cooling process of the waste heat boiler for fluidized bed gasification furnace with upward gas includes a high-temperature evaporator, a superheater, a low-temperature evaporator, and an economizer. Chinese utility model patent CN 208871582 U discloses a new type of waste heat boiler, which adopts a new type of waste heat boiler design combining a necked tube and a center tube. The coke powder is mainly concentrated in the center tube, which reduces the dust content in the waste heat boiler heat exchanger and reduces the wear of the heat exchanger and tube sheet by the coke powder. This structure cannot completely solve the problem of coke powder wearing the waste heat boiler because the gas temperature in the center tube is still high and the efficiency of collecting coke powder in the center tube is still low. A large amount of dust still enters the heat exchanger, which cannot completely solve the problem of coke powder wearing the waste heat boiler.

[0007] Chinese invention patent CN 102047038 B discloses a waste heat boiler for fluidized bed coal gasification process, which includes a high-temperature evaporator, a superheater, a low-temperature evaporator and an economizer, wherein the superheater, the low-temperature evaporator and the economizer adopt a water tube structure, and the high-temperature evaporator adopts a fire tube structure. This combination method is to first pass the waste heat boiler through a one-step cooling method and then send it to the dust collector for purification, but it was found in the actual operation of the industrial demonstration device that the heat exchanger of the integrated waste heat boiler still has problems of wear and corrosion, which is manifested in the serious wear of the fire tube at the coal gas inlet of the high-temperature evaporation section; especially the economizer water pipe shell is severely scaled, the dew point corrosion is serious, and the shutdown accidents occur most frequently. The above shows that the coal ash and dust entrained in the coal gas have a great impact on the equipment. Summary of the invention

[0008] In view of the above-mentioned shortcomings or deficiencies of the prior art, the technical problem to be solved by the present application is to provide an energy recovery and purification system for raw coal gas containing high-concentration coke powder particles.

[0009] To solve the above technical problems, this application is implemented through the following technical solutions:

[0010] A high-concentration coke powder particle gas energy recovery and purification system, comprising: an evaporator stage, a superheating stage, an evaporator stage 2, a cyclone separator, a high-efficiency dust collector and an economizer.

[0011] The first evaporator section, the superheating section and the second evaporator section are connected in sequence according to the upper, middle and lower positions to form a waste heat boiler;

[0012] The high-temperature gas enters the first stage of the evaporator for primary cooling, then passes through the hot stage for secondary cooling, and then passes through the second stage of the evaporator for tertiary cooling before being discharged from its outlet;

[0013] The outlet of the second section of the evaporator is connected to the cyclone separator through a pipeline, and the coal gas after centrifugal separation by the cyclone separator is discharged from the upper central pipe of the cyclone separator, and then passes through the second section of the evaporator and enters the high-efficiency dust collector and the economizer;

[0014] The locations of the high-efficiency dust collector and the economizer are interchangeable.

[0015] Furthermore, in the above-mentioned high-concentration coke powder particle gas energy recovery and purification system, the evaporator section and the superheating section are separated by a flexible tube sheet.

[0016] Furthermore, in the above-mentioned high-concentration coke powder particle gas energy recovery and purification system, a fire tube for coal gas to pass through is provided in the first section of the evaporator, wherein a first water flow channel for conveying boiler water is provided between the fire tube and the shell of the first section of the evaporator, wherein the flow direction of the boiler water is opposite to the flow direction of the coal gas.

[0017] Furthermore, in the above-mentioned high-concentration coke powder particle gas energy recovery and purification system, the fire tube is arranged at an angle, and a wear-resistant sleeve is arranged at the inlet of the fire tube.

[0018] Furthermore, in the above-mentioned high-concentration coke powder particle gas energy recovery and purification system, at least one water pipe is provided in the superheating section, wherein high-temperature saturated steam is introduced into the water pipe, and a flow channel between the outside of the water pipe and the shell of the superheating section is provided for the high-temperature gas to pass through.

[0019] Furthermore, in the above-mentioned high-concentration coke powder particle gas energy recovery and purification system, an inspection hole and a manhole are also provided on the shell of the superheating section.

[0020] Furthermore, in the above-mentioned high-concentration coke powder particle gas energy recovery and purification system, the second stage of the evaporator is provided with a first tube pass and a second tube pass,

[0021] Furthermore, in the above-mentioned high-concentration coke powder particulate gas energy recovery and purification system, the upper part of the first tube pass is connected to the superheating section, and the outlet of the first tube pass is connected to the cyclone separator through a pipeline;

[0022] Furthermore, in the above-mentioned high-concentration coke powder particle gas energy recovery and purification system, the lower part of the second tube pass is connected to the upper central tube of the cyclone separator, and the outlet of the second tube pass is connected to the high-efficiency dust collector or the economizer.

[0023] Furthermore, in the above-mentioned high-concentration coke powder particle gas energy recovery and purification system, a second water flow channel for conveying boiler water is also provided between the first tube pass and the shell of the second section of the evaporator, wherein the flow direction of the boiler water is opposite to the flow direction of the coal gas.

[0024] Furthermore, in the above-mentioned high-concentration coke powder particle gas energy recovery and purification system, the second stage of the evaporator adopts a fire tube structure.

[0025] Furthermore, in the above-mentioned high-concentration coke powder particle gas energy recovery and purification system, a plurality of straight-cut double-inlet centrifuge tubes are used inside the cyclone separator.

[0026] Furthermore, in the above-mentioned high-concentration coke powder particle gas energy recovery and purification system, the high-efficiency dust collector adopts a high-efficiency ceramic dust collector or a metal fiber dust collector.

[0027] Furthermore, in the above-mentioned high-concentration coke powder particle gas energy recovery and purification system, the dust content of the gas after filtering by the high-efficiency dust collector is reduced to 10 mg / Nm 3 the following.

[0028] Furthermore, in the above-mentioned high-concentration coke powder particle gas energy recovery and purification system, the economizer adopts a one-way fire tube structure, and a third water flow channel for deoxygenated water to pass through is also provided between the one-way fire tube structure and the shell of the economizer, wherein the flow direction of the deoxygenated water is opposite to the flow direction of the coal gas.

[0029] Furthermore, in the above-mentioned high-concentration coke powder particle gas energy recovery and purification system, the gas temperature at the economizer outlet is reduced to 160-210°C.

[0030] Compared with the prior art, this application has the following technical effects:

[0031] This application introduces a high-efficiency multi-tube cyclone separator and a high-efficiency dust collector in the middle link of the gas cooling process, so that the high-temperature dust-containing gas cooling and dust removal purification are organically integrated, rather than isolating the gas cooling and dust removal purification processes, solving the problems of wear, corrosion, and blockage of the heat exchange tubes in the low-temperature section during the gas cooling process, greatly extending the service life of the waste heat boiler and economizer, and is suitable for cooling and purifying high-temperature raw gas produced in the fluidized bed gasification field and the fluidized bed gasification field. The dust concentration at the outlet of the high-efficiency dust collector of this application can be reduced to 10mg / Nm 3 Below this, the gas temperature at the economizer outlet can be reduced to 160-210℃. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0033] Figure 1 : A structural schematic diagram of a first embodiment of a high-concentration coke powder particle gas energy recovery and purification system of the present application;

[0034] Figure 2: Schematic diagram of the structure of Example 2 of the high-concentration coke powder particle gas energy recovery and purification system of the present application. DETAILED DESCRIPTION

[0035] The concept, specific structure and technical effects of the present application will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present application.

[0036] Embodiment 1

[0037] like Figure 1 As shown, the high-concentration coke powder particle coal gas energy recovery and purification system of this embodiment includes: an evaporator section 1, a superheating section 2, an evaporator section 2, a cyclone separator 5, a high-efficiency dust collector 6 and an economizer 7. The evaporator section 1, the superheating section 2 and the evaporator section 2 are connected in sequence according to the upper, middle and lower positions to form a waste heat boiler; wherein, the high-temperature coal gas is cooled once from the evaporator section 1, then cooled twice through the hot section 2, and then cooled three times through the evaporator section 2 before being discharged from its outlet; the outlet of the evaporator section 2 is connected to the cyclone separator 5 through a pipeline, and the coal gas after centrifugal separation by the cyclone separator 5 is discharged from the upper center pipe of the cyclone separator 5, and then passes through the evaporator section 2 and enters the high-efficiency dust collector 6 and the economizer 7 in sequence.

[0038] The first section 1 of the evaporator is provided with a fire tube for gas to pass through, wherein a first water flow channel for conveying boiler water is provided between the fire tube and the shell of the first section 1 of the evaporator, wherein the water flow direction of the boiler water is opposite to the flow direction of the coal gas. Since the coal gas temperature at the inlet of the fire tube of the first section 1 of the evaporator reaches 850-1050°C, the coal gas inlet velocity is very high, in order to reduce the wear problem caused by the high gas velocity at the inlet of the fire tube, the fire tube is preferably arranged obliquely, wherein a wear-resistant sleeve is arranged at the inlet of the fire tube.

[0039] In this embodiment, the high-temperature raw coal gas from the fluidized bed gasifier or the entrained flow gasifier has a temperature of 850-1050°C and first enters the pipe box of the evaporator section 1 at the top of the waste heat boiler. The high-temperature coal gas is distributed to the fire tube through the pipe box, and the flow rate of the high-temperature coal gas entering the fire tube is controlled to be 15m / s-25m / s. Under such a flow rate, a wear-resistant sleeve is installed at the fire tube inlet pipe bundle. After the coal gas is rectified by the wear-resistant sleeve, it is not easy to wear quickly when it passes through the fire tube in a straight line. The high-temperature coal gas conducts convective heat transfer to the boiler water through the fire tube, and a steam-water mixture is formed on the shell side. The steam-water mixture is saturated steam. The pressure level can be different from 1.0Mpa to 5.0Mpa and the steam temperature can be different from 260-450°C according to user requirements. The high-temperature coal gas in the fire tube can be reduced to about 650°C at the outlet of the evaporator section 1.

[0040] In this embodiment, the high-temperature raw coal gas pressure may be in the range of 0.1 MPa to 5.0 MPa.

[0041] Furthermore, since the metal temperature of the tube wall of the fire tube of the evaporator section 1 is relatively high, while the metal wall temperature of the evaporator shell is relatively low, in order to eliminate the problem of inconsistent expansion between the fire tube and the shell and the problem of local enrichment of water vapor at the top, the evaporator section 1 is separated from the superheating section 2 by a flexible tube sheet.

[0042] Furthermore, the high-temperature coal gas at about 650°C enters the superheating section 2, wherein at least one water pipe is provided in the superheating section 2, wherein high-temperature saturated steam is introduced into the water pipe, and a flow channel between the outside of the water pipe and the shell of the superheating section 2 is provided for the high-temperature coal gas to pass through.

[0043] Among them, the water pipe is preferably a horizontal coil structure. The use of this coil structure ensures that there is no high-temperature superheated steam enrichment at the upper connecting tube plate, which is not easy to cause local overheating and further cause local high-temperature burning problems; in addition, this structure can make full use of space and the equipment cost is relatively low.

[0044] The shell of the superheating section 2 is also provided with inspection holes and manholes, so that the dust accumulation in the shell can be observed, and a dust blowing port or vibrator is provided so that when dust accumulation occurs, there are means to deal with the dust accumulation in time. The temperature of the high-temperature coal gas leaving the superheating section 2 drops to about 550°C.

[0045] In this embodiment, the second stage of the evaporator adopts a fire tube structure. When the coal gas flows to this point, the temperature has been reduced to about 550°C. Under the same flow area, the gas velocity of the coal gas is reduced by about 40%. The reduced gas velocity makes it easy for the coal ash and coke powder entrained in the coal gas to be deposited on the wall surface and cause ash accumulation. Therefore, in this embodiment, the second stage of the evaporator preferably adopts the two-tube pass fire tube structure (the first tube pass 3 and the second tube pass 4) described below, so that the gas velocity in the fire tube can be increased, ash is not easy to accumulate, and the convective heat transfer effect is better. The outlet of the first tube pass 3 is connected to the cyclone separator 5, and the semi-high temperature coal gas after dust removal enters the second tube pass 4 of the second stage of the evaporator to further exchange heat with the boiler water.

[0046] In this embodiment, the second section of the evaporator is provided with a first tube pass 3 and a second tube pass 4, the upper part of the first tube pass 3 is connected to the superheating section 2, and the outlet of the first tube pass 3 is connected to the cyclone separator 5 through a pipeline; the lower part of the second tube pass 4 is connected to the upper center tube of the cyclone separator 5, and the outlet of the second tube pass 4 is connected to the high-efficiency dust collector 6 or the economizer 7.

[0047] A second water flow channel for conveying boiler water is also provided between the first tube pass 3 and the shell of the second section of the evaporator, wherein the flow direction of the boiler water is opposite to the flow direction of the coal gas. The semi-high temperature coal gas after dust removal enters the second tube pass 4 of the second section of the evaporator for further heat exchange with the boiler water.

[0048] Furthermore, the high-temperature coal gas of about 550°C enters the first pipe pass 3, wherein the upper part of the first pipe pass 3 is directly welded to the lower pipe box of the superheating section 2, and the coal gas is distributed to each fire tube in the first pipe pass 3 through the pipe box. After the coal gas flows through the first pipe pass 3 from top to bottom, the temperature is reduced to about 400°C and exits the first pipe pass 3. The outlet of the first pipe pass 3 is connected to the high-efficiency multi-tube cyclone separator 5 through a pipeline. The pipeline preferably adopts a wear-resistant lining structure.

[0049] Among them, the cyclone separator 5 uses multiple straight-cut double-inlet centrifuge tubes inside, which has great operational flexibility and high separation efficiency; and this structure has small vortex core deformation and airflow is not easy to short-circuit. It is the first time to be used in the field of fluidized bed and fluidized bed dry dust removal.

[0050] The above-mentioned medium-temperature coal gas at about 400°C enters the cyclone separator 5 along the tangential rectangular opening, and the coal ash and coke separated by the cyclone separator 5 are transported out of the boundary area through the lower ash hopper and ash pump. The dust content of the medium-temperature coal gas after centrifugal dust removal by the cyclone separator 5 is greatly reduced, and the coal gas is discharged from the upper center pipe of the cyclone separator 5. Since the dust in the coal gas is reduced, the scouring of the equipment is reduced, and the service life of the subsequent equipment is extended. The above-mentioned medium-temperature coal gas enters the cyclone separator 5 to remove the coke powder with larger particles. Due to the low temperature of the medium-temperature coal gas, the cyclone dust removal efficiency is greatly improved.

[0051] The central tube of the cyclone separator 5 is connected to the lower tube box of the second tube pass 4 through a pipeline. The medium-temperature coal gas flows from bottom to top through the second tube pass 4 of the second section of the waste heat boiler evaporator, during which it further exchanges heat with the boiler water on the shell side. After the heat exchange, the temperature of the medium-temperature coal gas drops to about 260°C before leaving the waste heat boiler.

[0052] In this embodiment, the coal gas at about 260°C enters the high-efficiency dust collector 6. In this embodiment, the high-efficiency dust collector 6 is composed of a dust collector cylinder and its accessories (clean coal gas chamber, waste coal gas chamber, ash hopper), a filtering system, a pulse spray system, a dissipation system, etc. In view of the high operating temperature of the dust collector, the high-efficiency dust collector 6 is preferably made of wear-resistant, high-temperature-resistant, and non-brittle materials. For example, the high-efficiency dust collector 6 uses a high-efficiency ceramic dust collector or a metal fiber dust collector. The coal gas main is distributed to the high-efficiency dust collector 6 and enters the coal gas chamber. Dust with larger particles naturally settles due to gravity and enters the ash hopper, and dust with smaller particles rises with the coal gas. When passing through the filter bag, the dust is retained on the outer surface of the filter bag, and the coal gas is purified.

[0053] In this embodiment, the high-efficiency dust collector 6 has a high filtration wind speed and a significant filtration effect. The dust content of the gas after filtration by the high-efficiency dust collector 6 is reduced to 10 mg / Nm 3 Among them, the coal ash and dust in the coal gas are basically collected.

[0054] Furthermore, the dust content is ≤10mg / Nm 3 The purified coal gas is connected to the economizer 7 through the upper outlet of the high-efficiency dust collector 6. The economizer 7 adopts a one-way fire tube structure, and the ash removal effect is more obvious. The existing waste heat boiler economizer generally adopts a water pipe structure. Due to the decrease in coal gas temperature and the decrease in coal gas velocity, coal ash and coke powder are very easy to deposit on the water pipe shell. In addition, the coal gas is close to the dew point, and liquid water is very likely to appear, resulting in dew point corrosion and under-scale corrosion.

[0055] The present application adopts a fire tube structure, and the gas in the tube is in a turbulent state, which is not easy to accumulate dust, so that the service life of the heat exchange tube is greatly extended.

[0056] A third water flow channel for deoxygenated water at about 150°C is also provided between the one-way fire tube structure and the shell of the economizer 7, wherein the flow direction of the deoxygenated water is opposite to the flow direction of the coal gas. The coal gas at the outlet of the economizer 7 can be reduced to about 160-210°C, and the cooled synthesis gas enters the downstream conversion or desulfurization and decarbonization section after hot water washing or cold water washing.

[0057] The fire tube structure may be made of carbon steel or alloy steel. If alloy steel is used, the economizer 7 will have a better low-temperature corrosion resistance.

[0058] Furthermore, the economizer 7 adopts a reversing economizer structure, which further solves the problem of dust accumulation in the economizer 7 and effectively prevents the possibility of dew point corrosion and under-scale corrosion.

[0059] Embodiment 2

[0060] like Figure 2 As shown, the difference between this embodiment and the first embodiment is that the coal gas after passing through the second tube pass 4 of the second section of the evaporator first enters the economizer 7 and then enters the high-efficiency dust collector 6 for treatment.

[0061] The synthesis gas after cooling is washed with hot water or cold water and then enters the downstream conversion or desulfurization and decarbonization section.

[0062] It should be noted that, in this embodiment, the coal gas at about 260°C in the second tube pass 4 of the second section of the evaporator can first enter the economizer 7 to exchange heat with deoxygenated water at about 150°C, and the coal gas at 160-210°C after heat exchange enters the high-efficiency dust collector 6. With such a process configuration, although the coal gas entering the economizer 7 has a high dust content, which may affect the service life of the economizer 7, the filter element material of the high-efficiency dust collector can be selected from low-priced polymers, which reduces the cost.

[0063] In actual application, the specific selection of the process combination of the first embodiment or the second embodiment can be determined by comprehensively considering the cost and stability.

[0064] The present invention introduces a high-efficiency multi-cyclone separator and a high-efficiency dust collector in the middle link of the gas cooling process, so that the dust concentration at the outlet of the high-efficiency dust collector can be reduced to 10mg / Nm 3 The gas temperature at the economizer outlet can be reduced to 160-210°C, which solves the problems of wear, corrosion, and blockage of the heat exchange tubes in the low-temperature section during the gas cooling process, greatly prolongs the service life of the waste heat boiler and economizer, and is suitable for cooling and purifying high-temperature raw coal gas produced in the fluidized bed gasification field and the entrained flow bed gasification field. Therefore, the application prospect of this application is broad.

[0065] It should be understood that, although the terms first, second, third, etc. may be used to describe certain components in the embodiments of the present application, these components should not be limited to these terms. These terms are only used to distinguish the components from each other. For example, without departing from the scope of the embodiments of the present application, the first so-and-so component may also be referred to as the second so-and-so component, and similarly, the second so-and-so component may also be referred to as the first so-and-so component.

[0066] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such a product or system. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the product or system including the elements.

[0067] The above embodiments are only used to illustrate the technical solution of the present application but not to limit it. The present application is described in detail with reference to the preferred embodiments. It should be understood by those skilled in the art that the technical solution of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application, and should be included in the scope of the claims of the present application.

Claims

1. A system for recovering and purifying coal gas containing high-concentration coke powder particles, characterized in that: include: Evaporator stage 1, superheater stage, evaporator stage 2, cyclone separator, high efficiency dust collector and economizer, The first section of the evaporator, the superheating section and the second section of the evaporator are connected in order according to the upper, middle and lower positions to form a waste heat boiler; the first section of the evaporator is separated from the superheating section by a flexible tube sheet; a fire tube for gas to pass through is provided in the first section of the evaporator, wherein a first water flow channel for conveying boiler water is provided between the fire tube and the shell of the first section of the evaporator, and the water flow direction of the boiler water is opposite to the flow direction of the gas; The high-temperature gas enters the first stage of the evaporator for primary cooling, then passes through the hot stage for secondary cooling, and then passes through the second stage of the evaporator for tertiary cooling before being discharged from its outlet; The outlet of the second section of the evaporator is connected to the cyclone separator through a pipeline, and the coal gas after centrifugal separation by the cyclone separator is discharged from the upper central pipe of the cyclone separator, and then passes through the second section of the evaporator and enters the high-efficiency dust collector and the economizer; The locations of the high-efficiency dust collector and the economizer are interchangeable.

2. The high-concentration coke powder particulate gas energy recovery and purification system according to claim 1 is characterized in that: The fire tube is arranged obliquely, wherein a wear-resistant sleeve is arranged at the inlet of the fire tube.

3. The high-concentration coke powder particulate gas energy recovery and purification system according to claim 1 or 2, characterized in that: At least one water pipe is provided in the superheating section, wherein high-temperature saturated steam is introduced into the water pipe, and a flow channel between the outside of the water pipe and the shell of the superheating section is provided for high-temperature gas to pass through.

4. The high-coke particle gas energy recovery and purification system according to claim 3 is characterized in that: The shell of the overheating section is also provided with an inspection hole and a manhole.

5. The high-concentration coke powder particulate gas energy recovery and purification system according to claim 1 or 2, characterized in that: The second section of the evaporator is provided with a first tube pass and a second tube pass. Wherein, the upper part of the first pipe pass is connected to the superheating section, and the outlet of the first pipe pass is connected to the cyclone separator through a pipeline; The lower part of the second tube pass is connected to the upper central tube of the cyclone separator, and the outlet of the second tube pass is connected to the high-efficiency dust collector or the economizer.

6. The high-concentration coke powder particulate gas energy recovery and purification system according to claim 5 is characterized in that: A second water flow channel for conveying boiler water is also provided between the first tube pass and the shell of the second section of the evaporator, wherein the flow direction of the boiler water is opposite to the flow direction of the coal gas.

7. The high-coke particle gas energy recovery and purification system according to claim 5 is characterized in that: The second stage of the evaporator adopts a fire tube structure.

8. The high-concentration coke powder particulate gas energy recovery and purification system according to claim 1 or 2, characterized in that: The cyclone separator uses a plurality of straight-cut double-inlet centrifuge tubes inside.

9. The high-coke particle gas energy recovery and purification system according to claim 1 is characterized in that: The high-efficiency dust collector adopts a high-efficiency ceramic dust collector or a metal fiber dust collector.

10. The energy recovery and purification system for coal gas containing high-concentration coke powder particles according to claim 1, 2 or 9, characterized in that: The dust content of the coal gas after filtering by the high-efficiency dust collector is reduced to 10mg / Nm 3 the following.

11. The energy recovery and purification system for coal gas containing high-concentration coke powder particles according to claim 1, 2 or 9, characterized in that: The economizer adopts a one-way fire tube structure, and a third water flow channel for deoxygenated water to pass through is provided between the one-way fire tube structure and the shell of the economizer, wherein the flow direction of the deoxygenated water is opposite to the flow direction of the coal gas.

12. The energy recovery and purification system for coal gas containing high-concentration coke powder particles according to claim 1, 2 or 9, characterized in that: The coal gas temperature at the economizer outlet drops to 160-210°C.

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