Air-cooled slag cooler and circulating fluidized bed using the same

Abstract

The present invention provides an air-cooled slag cooler and a circulating fluidized bed using the air-cooled slag cooler, the air-cooled slag cooler comprising an outer shell and a spacer, the outer shell having a slag cooler cavity, a first air inlet, a first air outlet, a slag inlet and a slag outlet, the slag cooler cavity comprising a main cavity and a cooling air trough; the spacer is arranged in the slag cooler cavity and is provided with an air guide port connecting the main cavity and the cooling air trough; the cooling air trough is used to receive slag to be cooled discharged from the boiler through the slag inlet, the first air inlet is used to receive incoming air so that the incoming air absorbs heat from the slag to be cooled in the cooling air trough to form hot air and cool the slag, and the hot air is returned to the boiler via the air guide port, the main cavity and the first air outlet, and the slag outlet is used to discharge the cooled slag.

Description

Technical Field

[0001] The present application relates to the technical field of slag coolers, and in particular to an air-cooled slag cooler and a circulating fluidized bed using the air-cooled slag cooler. Background Art

[0002] The bottom ash discharged from fluidized bed boilers is a kind of solid particles with wide screening (0-30mm) and high temperature (~900℃), which is difficult to operate and control, especially for large-capacity (or large slag volume) CFB boilers. There is no good solution at home and abroad. Therefore, the slag cooler is one of the most difficult technical difficulties in the auxiliary system of fluidized bed boilers.

[0003] At present, there are many methods and equipment for cooling the bottom slag of circulating fluidized bed on the market, such as slag cooler of wind-water combined circulating fluidized bed, mechanical slag cooler, etc. The slag cooler of wind-water combined circulating fluidized bed cannot achieve the expected cooling effect due to the existence of slagging, failure of boiler slag discharge control and wear of the cooling and heating surface of the slag cooler, which has caused great economic losses to the power plant. Some mechanical slag coolers, such as water-cooled auger and water-cooled drum, are not very optimistic in application prospects due to the problems of poor sealing, poor cooling capacity and large workload of overhaul and maintenance. Summary of the invention

[0004] In view of this, it is necessary to provide an air-cooled slag cooler suitable for fluidized bed combustion of high-ash, low-calorific value fuels and a circulating fluidized bed using the air-cooled slag cooler.

[0005] In a first aspect, an embodiment of the present application provides an air-cooled slag cooler, comprising:

[0006] A shell, wherein the shell has a slag cooler cavity, a first air inlet, a first air outlet, a slag inlet and a slag outlet, the slag cooler cavity includes a main cavity and a cooling air trough, the main cavity is connected to the first air outlet, and the cooling air trough is connected to the slag inlet, the slag outlet and the first air inlet respectively;

[0007] A spacer is arranged in the slag cooler cavity, between the main cavity and the cooling air trough, and the spacer is also provided with an air guide port connecting the main cavity and the cooling air trough;

[0008] Among them, the cooling air trough is used to receive the slag to be cooled discharged from the boiler through the slag inlet, the first air inlet is used to receive the incoming air so that the incoming air absorbs the heat in the slag to be cooled in the cooling air trough to form hot air and cool the slag, and the hot air is returned to the boiler through the air guide port, the main cavity and the first air outlet, and the slag outlet is used to discharge the cooled slag.

[0009] The air-cooled slag cooler provided in the embodiment of the present application is purely air-cooled. No heating surface is arranged in the cavity of the air-cooled slag cooler. The inlet air of the boiler is used to cool the slag to be cooled discharged from the furnace. A higher wind speed can be used. The slag to be cooled and the inlet air are strongly mixed, so that the unburned combustibles in the slag to be cooled are further intensified for combustion, thereby reducing the heat loss of the combustibles in the slag to be cooled, improving the boiler efficiency, greatly reducing the volume of the air-cooled slag cooler, and also ensuring the smooth flow of the slag to be cooled in the air-cooled slag cooler, thereby reducing the problems of slag blockage and wear of the air-cooled slag cooler.

[0010] It can be understood that the slag cooler cavity is divided into a main cavity and a cooling air trough by the partition, and the cooling air trough is used to receive the slag to be cooled discharged from the boiler through the slag inlet, and receive the incoming air through the first air inlet, so as to realize the heat exchange between the slag to be cooled and the incoming air to form hot air and cooling slag. This design of the air-cooled slag cooler cavity enables the air-cooled slag cooler to have a sorting function, and part of the fine particles and unreacted desulfurizer are returned to the boiler as the boiler combustion air through the air guide port, the main cavity and the first air outlet along with the hot air after heat exchange, and continue to participate in the combustion of the fuel in the boiler, thereby improving the boiler combustion efficiency and reducing the amount of desulfurizer, and also increasing the flow rate of fine particles in the furnace of the circulating fluidized bed, and increasing the proportion of fine particles in the circulating fluidized bed material circulation, thereby improving the heat transfer in the boiler furnace. The slag outlet is used to discharge the cooled slag, and all the control equipment of the air-cooled slag cooler, such as the slag discharge control valve, are installed in the area where the cold slag is in contact, which greatly improves the reliability and safety of the control equipment of the air-cooled slag cooler.

[0011] In one embodiment, the shell includes: a contact wall for connecting the boiler, provided with the first air outlet and the slag inlet, the first air outlet and the slag inlet are respectively connected to the furnace of the boiler; an outer wall, arranged opposite to the contact wall, provided with the first air inlet; a connecting side wall, connected between the contact wall and the outer wall, used to enclose the slag cooler cavity together with the contact wall and the outer wall, provided with the slag outlet; the spacer is connected between the contact wall and the outer wall. The air-cooled slag cooler is arranged outside the conical part of the lower side of the furnace of the boiler, and the contact wall of the air-cooled slag cooler is connected to the boiler, which is convenient to arrange and saves space. The contact wall is connected to the furnace of the boiler through the slag inlet and the first air outlet, so as to receive the slag to be cooled and the hot air discharged after heat exchange to the furnace for further reaction.

[0012] In one embodiment, the contact wall is used to connect to the furnace wall of the boiler, and the inner surface of the contact wall is overlapped and connected with the outer surface of the furnace wall of the boiler, so as to facilitate the material exchange between the air-cooled slag cooler and the furnace.

[0013] In one embodiment, at least the contact wall among the contact wall, the outer wall and the connecting side wall is a water-cooled wall; at least part of the furnace wall of the boiler connected to the contact wall is a water-cooled wall. At least the contact wall in the outer shell connected to the furnace wall of the boiler is formed as a water-cooled wall, so that the air-cooled slag cooler is safe and reliable, and is convenient for thermal insulation design.

[0014] In one embodiment, the air-cooled slag cooler further comprises a wear-resistant layer, and the wear-resistant layer is provided on the inner surface of the contact wall, the outer wall, and the connecting side wall; the wear-resistant layer is a non-metallic wear-resistant layer. The non-metallic wear-resistant layer is laid on the inner surface of the air-cooled slag cooler cavity, so a higher wind speed can be used, the slag to be cooled and the incoming air are mixed strongly, the volume of the air-cooled slag cooler is greatly reduced, and the incoming air and the slag to be cooled can be mixed at a high speed and fully in the cooling air trough, thereby improving the degree of heat exchange.

[0015] In one embodiment, the connecting side wall includes a first connecting side wall and a second connecting side wall opposite to the first connecting side wall, the first connecting side wall, the spacer and the second connecting side wall are sequentially arranged along a first preset direction; the first air outlet is arranged at a portion of the contact wall close to the first connecting side wall; the slag inlet is arranged at a portion of the contact wall close to the second connecting side wall; the slag outlet is arranged on the second connecting side wall, and the first air inlet is arranged at a portion of the outer wall close to the second connecting side wall. The first connecting side wall, the spacer and the second connecting side wall are sequentially arranged along a first preset direction, and the first preset direction is from top to bottom when the air-cooled slag cooler is working, and the first connecting side wall, the spacer and the second connecting side wall are used to connect the outer wall and the contact wall. The setting of the partition wall facilitates the later maintenance and replacement of some parts of the air-cooled slag cooler.

[0016] In one embodiment, the connecting side wall includes a third connecting side wall and a fourth connecting side wall opposite to the third connecting side wall, and the third connecting side wall and the fourth connecting side wall are arranged in sequence along a second preset direction; the spacer includes a first part and a second part, the first part connects the third connecting side wall, the second part connects between the first part and the fourth connecting side wall, and the first air inlet is arranged on the fourth connecting side wall; the slag inlet is arranged on a part of the contact wall close to the third connecting side wall, and the slag outlet is arranged on a part of the second connecting side wall close to the fourth side wall, and the cooling air trough is divided into a slag inlet part corresponding to the first part and connected to the slag inlet, and a cooling part connected between the slag inlet part and the slag outlet and connected to the air guide port; the slag inlet part extends in a direction perpendicular to the second preset direction, and the cooling part extends in the second preset direction. The third connecting side wall and the fourth connecting side wall are arranged in sequence along the second preset direction. The second preset direction is from right to left when the air-cooled slag cooler is working. The cooling air trough is divided into a slag feeding part and a cooling part, and the slag feeding part is close to the furnace, while the cooling part is far away from the furnace, thereby ensuring the smooth flow of the slag to be cooled and the incoming air between the chambers, avoiding problems such as slag blockage.

[0017] In one embodiment, the first part includes a first connecting plate and a second connecting plate, one end of the first connecting plate is connected to the third connecting side wall, one end of the second connecting plate is bent and connected to an end of the first connecting plate away from the third connecting side wall, and the other end of the second connecting plate is bent and connected to the second part; the second part includes a third connecting plate, and the third connecting plate is connected between the second connecting plate and the fourth connecting side wall; the first connecting plate is vertically connected to the third connecting side wall; the first connecting plate is vertically connected to the second connecting plate, and the third connecting plate is vertically connected to the second connecting plate and the fourth connecting side wall, the distance between the first connecting plate and the second connecting side wall is greater than the distance between the third connecting plate and the second connecting side wall, and the end of the second connecting plate away from the first connecting plate protrudes from the third connecting plate, so that the distance between the second connecting plate and the second connecting side wall is less than the distance between the third connecting plate and the second connecting side wall. It can be understood that the distance between the first connecting plate and the second connecting side wall is greater than the distance between the third connecting plate and the second connecting side wall, so that the slag to be cooled can smoothly enter the cooling part of the cooling air trough for heat exchange by utilizing the slope of the slag inlet part; the end of the second connecting plate away from the first connecting plate protrudes from the third connecting plate, so that the distance between the second connecting plate and the second connecting side wall is less than the distance between the third connecting plate and the second connecting side wall, so that the hot air formed after the heat exchange enters the main cavity through the air guide port on the spacer to avoid the hot air and the slag to be cooled merging in the slag inlet part to affect the cooling effect.

[0018] In one embodiment, the air-cooled slag cooler further comprises an air duct assembly, the air duct assembly is used to connect the first air inlet to provide the air inlet; the air duct assembly is arranged on the side of the outer wall away from the contact wall; the air duct assembly comprises an air inlet main pipe and an air guide pipe connected between the air inlet main pipes. The air inlet can be primary air or secondary air with a low pressure head, which greatly reduces the energy consumption of the air-cooled slag cooler itself. The speed, flow rate and particle size of the slag to be cooled are adjusted by the flow rate of the air inlet, and the adjustment is safe and reliable, which greatly reduces the failure rate of the current circulating fluidized bed boiler slag discharge system to be cooled.

[0019] In a second aspect, an embodiment of the present application further provides a circulating fluidized bed, the circulating fluidized bed comprising:

[0020] Air-cooled slag cooler;

[0021] A boiler having a boiler wall surrounding a furnace, wherein the boiler wall is provided with a heat exhaust port, a return air port, a slag discharge port and a return material port, wherein the heat exhaust port, the return air port, the slag discharge port and the return material port are respectively connected to the furnace, the slag discharge port is connected to a slag inlet of the air-cooled slag cooler, and the return air port is connected to a first air outlet of the air-cooled slag cooler;

[0022] A cyclone separator, comprising a shell and a separator body, the shell having a chamber and a second air inlet, a second air outlet and a discharge port connected to the chamber, the separator being located in the chamber, the second air inlet of the cyclone separator being connected to the heat exhaust port of the boiler for receiving the flue gas discharged from the boiler and performing gas-material separation on the flue gas to form fly ash and coarse particles, the separated fly ash being discharged via the second air outlet, and the separated coarse particles being discharged via the discharge port of the cyclone separator;

[0023] A material return device connected between the material discharge port of the cyclone separator and the material return port of the boiler;

[0024] The convection air duct is connected to the second air outlet of the cyclone separator and is used for discharging the separated fly ash. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0026] Figure 1 It is a schematic diagram of the planar structure of an air-cooled slag cooler;

[0027] Figure 2 It is a schematic diagram of the principle of an air-cooled slag cooler;

[0028] Figure 3 It is a schematic diagram of the planar structure of a circulating fluidized bed in the present application.

[0029] 100-air-cooled slag cooler; 11-housing; 12-slag cooler cavity; 13-first air inlet; 14-first air outlet; 15-slag inlet; 16-slag outlet; 17-spacer; 18-air guide; 19-air duct assembly; 111-contact wall; 112-outer wall; 113-connecting side wall; 113a-first connecting side wall; 113b-second connecting side wall; 113c-third connecting side wall; 113d-fourth connecting side wall; 121-main cavity; 122-cooling air trough; 171-first part; 172-second part; 122a-slag inlet part; 122b-cooling part; 171a-first connecting plate; 171b-second connecting plate; 172a-third connecting plate; 191-air inlet main pipe; 192-air guide;

[0030] 200-circulating fluidized bed; 21-boiler, 22-cyclone separator; 23-returning device; 24-convection air duct 211-furnace; 212-boiler wall; 213-heat exhaust port; 214-return air port; 215-slag discharge port; 216-returning port; 221-shell; 222-separator body; 223-chamber; 224-second air inlet, 225-second air outlet, 226-discharging port. DETAILED DESCRIPTION

[0031] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thoroughly and comprehensively understood.

[0032] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "inside", "outside", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0034] See also Figure 1 , Figure 1It is a schematic diagram of the planar structure of the air-cooled slag cooler 100 in this embodiment, the air-cooled slag cooler 100 includes an outer shell 11 and a partition wall 17, the outer shell 11 has a slag cooler cavity 12, a first air inlet 13, a first air outlet 14, a slag inlet 15 and a slag outlet 16; the slag cooler cavity includes a main cavity 121 and a cooling air groove 122, the partition 17 is arranged in the slag cooler cavity 12, and is used to divide the slag cooler cavity 12 into the main cavity 121 and the cooling air groove 122, the main cavity 121 is connected to the first air outlet 14, the cooling air groove 122 is connected to the slag inlet 15, the slag outlet 16 and the first air inlet 13 respectively, and the partition 17 is also provided with an air guide 18 connecting the main cavity 121 and the cooling air groove 122.

[0035] Among them, the cooling air groove 122 is used to receive the slag to be cooled discharged from the boiler 21 through the slag inlet 15, the first air inlet 13 is used to receive the incoming air so that the incoming air absorbs the heat in the slag to be cooled in the cooling air groove 122 to form hot air and cool the slag, and the hot air is returned to the boiler 21 through the air guide port 18, the main cavity 121 and the first air outlet 14, and the slag outlet 16 is used to discharge the cooled slag.

[0036] The air-cooled slag cooler 100 provided in the present embodiment is purely air-cooled. No heating surface is arranged in the slag cooler cavity 12. The intake air of the boiler 21 is used to cool the slag to be cooled discharged from the furnace 211. A higher wind speed can be used. The slag to be cooled and the intake air are strongly mixed, so that the unburned combustibles in the slag to be cooled are further intensified for combustion, reducing the heat loss of the combustibles in the slag to be cooled, improving the efficiency of the boiler 21, greatly reducing the volume of the air-cooled slag cooler 100, and also ensuring the smooth flow of the slag to be cooled in the air-cooled slag cooler 100, reducing the problems of slag blockage and wear of the air-cooled slag cooler 100.

[0037] It can be understood that the slag cooler cavity 12 is divided into a main cavity 121 and a cooling air trough 122 by the spacer 17. The cooling air trough 122 is used to receive the slag to be cooled discharged from the boiler 21 through the slag inlet 15, and receive the incoming air through the first air inlet 13, so as to realize the heat exchange between the slag to be cooled and the incoming air to form hot air and cool the slag. This design of the slag cooler cavity 12 enables the air-cooled slag cooler 100 to have a sorting function. Some fine particles and unreacted desulfurizer are returned to the boiler 21 along with the hot air after heat exchange through the air guide port 18, the main cavity 121 and the first air outlet 14, and continue to participate in the combustion of the fuel in the boiler 21 as the combustion air of the boiler 21, thereby improving the combustion efficiency of the boiler 21 and reducing the amount of desulfurizer used. It can also increase the flow rate of fine particles in the furnace 211 of the circulating fluidized bed 200, and increase the proportion of fine particles in the material circulation of the circulating fluidized bed 200, thereby improving the heat transfer in the boiler 21. The slag outlet 16 is used to discharge the cooled slag. All control devices of the air-cooled slag cooler 100, such as the slag discharge control valve, are installed in the area where the cooled slag contacts, which greatly improves the reliability and safety of the control devices of the air-cooled slag cooler 100.

[0038] Furthermore, the air-cooled slag cooler 100 is arranged on the outer side of the conical part of the lower side of the furnace 211 of the boiler 21, and the shell 11 includes a contact wall 111, an outer wall 112 and a connecting side wall 113. The contact wall 111 is used to connect the boiler 21, which is convenient to arrange and saves space. The first air outlet 14 and the slag inlet 15 are arranged on it. The first air outlet 14 and the slag inlet 15 are respectively connected to the furnace 211 of the boiler to receive the slag to be cooled and the slag after heat exchange. The hot air is discharged to the furnace 211 for further reaction; the outer wall 112 is arranged opposite to the contact wall 111, and the first air inlet 13 is arranged thereon; the connecting side wall 113 is connected between the contact wall 111 and the outer wall 112, and is used to enclose the slag cooler cavity 12 together with the contact wall 111 and the outer wall 112, and the slag outlet 16 is arranged on the connecting side wall 113; the spacer 17 is connected between the contact wall 111 and the outer wall 112.

[0039] Furthermore, the contact wall 111 is used to connect with the boiler wall 212 of the boiler 21 , and the inner surface of the contact wall 111 is overlapped and connected with the outer surface of the boiler wall 212 of the boiler 21 , so as to facilitate the material exchange between the air-cooled slag cooler 100 and the furnace 211 .

[0040] Further, at least the contact wall 111 among the contact wall 111, the outer wall 112, and the connecting side wall 113 is a water-cooled wall; at least part of the boiler wall 212 of the boiler 21 connected to the contact wall 111 is a water-cooled wall. At least the contact wall 111 in the outer shell 11 connected to the boiler wall 212 of the boiler 21 is formed as a water-cooled wall, so that the air-cooled slag cooler 100 is safe and reliable, and is convenient for thermal insulation design.

[0041] Furthermore, the air-cooled slag cooler 100 also includes a wear-resistant layer, which is arranged on the inner surface of the contact wall 111, the outer wall 112, and the connecting side wall 113; the wear-resistant layer is a non-metallic wear-resistant layer. The non-metallic wear-resistant layer is applied to the inner surface of the slag cooler cavity 12, so a higher wind speed can be used, and the slag to be cooled is mixed with the incoming air, which greatly reduces the volume of the air-cooled slag cooler 100, and can achieve high-speed and full mixing of the incoming air and the slag to be cooled in the cooling air trough 122, thereby improving the degree of heat exchange. The non-metallic wear-resistant layer can be selected from polymer wear-resistant materials, ceramic wear-resistant materials, or composite wear-resistant materials.

[0042] Further, the connecting side wall 113 includes a first connecting side wall 113a and a second connecting side wall 113b opposite to the first connecting side wall 113a, and the first connecting side wall 113a, the spacer 17 and the second connecting side wall 113b are arranged in sequence along a first preset direction; the first air outlet 14 is arranged at a portion of the contact wall 111 close to the first connecting side wall 113a; the slag inlet 15 is arranged at a portion of the contact wall 111 close to the second connecting side wall 113b; the slag outlet 16 is arranged on the second connecting side wall 113b, and the first air inlet 13 is arranged at a portion of the outer wall 112 close to the second connecting side wall 113b. The first connecting side wall 113a, the spacer 17 and the second connecting side wall 113b are sequentially arranged along a first preset direction, which is a direction from top to bottom when the air-cooled slag cooler 100 is working. The first connecting side wall 113a, the spacer 17 and the second connecting side wall 113b are used to connect the outer wall 112 and the contact wall 111. The housing 11 adopts such a wall arrangement to facilitate the later maintenance and replacement of some parts of the air-cooled slag cooler 100.

[0043] Furthermore, if Figure 2As shown, the connecting side wall 113 includes a third connecting side wall 113c and a fourth connecting side wall 113d opposite to the third connecting side wall 113c, and the third connecting side wall 113c and the fourth connecting side wall 113d are sequentially arranged along a second preset direction; the spacer 17 can be a partition wall, including a first part 171 and a second part 172, the first part 171 connects the third connecting side wall 113c, and the second part 172 connects the first part 171 and the fourth connecting side wall 113d, and the first air inlet 13 is arranged on the fourth connecting side wall 113d; the slag inlet 15 is arranged at the part of the contact wall 111 close to the third connecting side wall 113c, the slag outlet 16 is arranged at the part of the second connecting side wall 113b close to the fourth connecting side wall 113d, the cooling air groove 122 is divided into a slag inlet part 122a corresponding to the first part 171 and connected to the slag inlet 15 and a cooling part 122b connected between the slag inlet part 122a and the slag outlet 16 and connected to the air guide 18; the slag inlet part 122a extends in a direction perpendicular to the second preset direction, and the cooling part 122b extends in the second preset direction. The third connecting side wall 113c and the fourth connecting side wall 113d are arranged in sequence along the second preset direction, and the second preset direction is from right to left when the air-cooled slag cooler 100 is working. The cooling air groove 122 is divided into a slag inlet part 122a and a cooling part 122b, which ensures that the slag to be cooled and the air inlet flow between each chamber smoothly, avoiding slag blocking and other problems.

[0044] Specifically, the first part 171 includes a first connecting plate 171a and a second connecting plate 171b, one end of the first connecting plate 171a is connected to the third connecting side wall 113c, one end of the second connecting plate 171b is bent and connected to one end of the first connecting plate 171a away from the third connecting side wall 113c, and the other end of the second connecting plate 171b is bent and connected to the second part 172; the second part 172 includes a third connecting plate 172a, and the third connecting plate 172a is connected between the second connecting plate 171b and the fourth connecting side wall 113d; the first connecting plate 171a is vertically connected to the third connecting side wall 113c; The first connecting plate 171a is vertically connected to the second connecting plate 171b, the third connecting plate 172a is vertically connected to the second connecting plate 171b and the fourth connecting side wall 113d, the distance between the first connecting plate 171a and the second connecting side wall 113b is greater than the distance between the third connecting plate 172a and the second connecting side wall 113b, and one end of the second connecting plate 171b away from the first connecting plate 171a protrudes from the third connecting plate 172a, so that the distance between the second connecting plate 171b and the second connecting side wall 113b is smaller than the distance between the third connecting plate 172a and the second connecting side wall 113b. It can be understood that the distance between the first connecting plate 171a and the second connecting side wall 113b is greater than the distance between the third connecting plate 172a and the second connecting side wall 113b, so that the slag to be cooled can smoothly enter the cooling part 122b of the cooling air trough 122 for heat exchange by utilizing the slope of the slag inlet part 122a; the end of the second connecting plate 171b away from the first connecting plate 171a protrudes from the third connecting plate 172a, so that the distance between the second connecting plate 171b and the second connecting side wall 113b is less than the distance between the third connecting plate 172a and the second connecting side wall 113b, so that the hot air formed after the heat exchange enters the main cavity 121 through the air guide port 18 on the spacer 17 to avoid the hot air and the slag to be cooled from merging in the slag inlet part 122a to affect the cooling effect.

[0045] Furthermore, the air-cooled slag cooler 100 further includes an air duct assembly 19, which is used to connect the first air inlet 13 to provide the air intake; the air duct assembly 19 is arranged on the side of the outer wall 112 away from the contact wall 111; the air duct assembly 19 includes an air intake main pipe 191 and an air guide pipe 192 connected between the air intake main pipe 191. The air intake can be primary air or secondary air with a low pressure head, which greatly reduces the energy consumption of the air-cooled slag cooler 100 itself. The speed, flow rate and particle size of the slag to be cooled are adjusted by the flow rate of the air intake, and the adjustment is safe and reliable, which greatly reduces the failure rate of the slag to be cooled discharge system of the boiler 21 of the circulating fluidized bed 200.

[0046] like Figure 3 As shown, Figure 3 The present invention is a schematic diagram of a planar structure of a circulating fluidized bed, wherein the circulating fluidized bed 200 comprises: an air-cooled slag cooler 100, a boiler 21, a cyclone separator 22, a material return device 23 and a convection air duct 24, wherein the boiler 21 has a boiler wall 212 surrounding a furnace 211, wherein the boiler wall 212 is provided with a heat exhaust port 213, a return air port 214, a slag exhaust port 215 and a material return port 216, wherein the heat exhaust port 213, the return air port 214, the slag exhaust port 215 and the material return port 216 are respectively connected to the furnace 211, wherein the slag exhaust port 215 is connected to the slag inlet 15 of the air-cooled slag cooler 100, and the return air port 214 is connected to the first air outlet 14 of the air-cooled slag cooler 100; wherein the cyclone separator 22 comprises a shell 221 and a separator body 222, wherein the shell 221 has a cavity The separator body 222 is located in the chamber 223, and the second air inlet 224, the second air outlet 225 and the discharge port 226 communicated with the chamber 223. The second air inlet 224 of the cyclone separator 22 is connected to the heat exhaust port 213 of the boiler 21 for receiving the flue gas discharged from the boiler 21 and performing gas-material separation on the flue gas to form fly ash and coarse particles. The separated fly ash is discharged through the second air outlet 225, and the separated coarse particles are discharged through the discharge port 226 of the cyclone separator 22; the return device 23 is connected between the discharge port 226 of the cyclone separator 22 and the return port 216 of the boiler 21; the convection air duct 24 is connected to the second air outlet 225 of the cyclone separator 22 for discharging the separated fly ash.

[0047] The implementation process of air-cooled slag cooler is:

[0048] The slag to be cooled of the circulating fluidized bed 200 boiler 21 is discharged from the slag discharge port 215 (the slag temperature is generally 800-900°C), and enters the cooling air slot 122 through the slag inlet 15 of the air-cooled slag cooler 100. During the flow of the slag to be cooled, the boiler 21 supplies air (primary air or secondary air, generally at a temperature of about 300°C) from the air inlet main pipe 191 through the air guide pipe 192 and is sprayed into the slot along the entire length of the cooling air slot 122, and heat is exchanged with the slag to be cooled to form hot air and cooling slag. The cooling slag is continuously cooled along the cooling air slot 122. After cooling, the hot air flows to the slag outlet 16 and is discharged from the air-cooled slag cooler 100. The hot air carries a small amount of fine ash and incompletely reacted desulfurizer and is returned to the boiler 21 through the air guide port 18, the main cavity 121 and the first air outlet 14 to serve as the combustion air of the boiler 21 and continue to participate in the combustion of the fuel in the boiler 21, thereby improving the combustion efficiency of the boiler 21 and reducing the amount of desulfurizer used. It can also increase the flow rate of fine particles in the furnace 211 of the circulating fluidized bed 200, increase the proportion of fine particles in the material circulation of the circulating fluidized bed 200, and thus improve the heat transfer in the boiler 21.

[0049] The implementation process of the circulating fluidized bed 200 is as follows:

[0050] The fuel and the bed material constituting the circulating fluidized bed 200 are burned in the furnace 211, and the flue gas generated by the combustion enters the cyclone separator 22 through the heat exhaust port 213 and the second air inlet 224. The separated coarse particles enter the return device 23 through the discharge port 226 and return to the furnace 211 for circulating combustion. The remaining fine particles form fly ash and are discharged from the second air outlet 225 at the top of the cyclone separator 22 into the rear convection air duct 24.

[0051] The technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above-described embodiments only express several implementation methods of the present application, and the description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several deformations and improvements can be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of this application shall be based on the attached claims.

Claims

1. An air-cooled slag cooler, characterized in that: The air-cooled slag cooler comprises: A shell, wherein the shell has a slag cooler cavity, a first air inlet, a first air outlet, a slag inlet and a slag outlet, the slag cooler cavity includes a main cavity and a cooling air trough, the main cavity is connected to the first air outlet, and the cooling air trough is connected to the slag inlet, the slag outlet and the first air inlet respectively; the shell includes an outer wall and a contact wall; 14. The cooling air duct of claim 13 wherein the at least one air duct is an air intake port and a cooling air intake port is provided to cool the cooling air duct in an outwardly directed direction. Among them, the cooling air trough is used to receive the slag to be cooled discharged from the boiler through the slag inlet, the first air inlet is used to receive the incoming air so that the incoming air absorbs the heat in the slag to be cooled in the cooling air trough to form hot air and cool the slag, and the hot air is returned to the boiler through the air guide port, the main cavity and the first air outlet, and the slag outlet is used to discharge the cooled slag.

2. The air-cooled slag cooler according to claim 1, characterized in that: The housing further comprises a connecting side wall, The contact wall is used to connect the boiler and is provided with the first air outlet and the slag inlet, and the first air outlet and the slag inlet are respectively connected to the furnace of the boiler; The outer wall is arranged opposite to the contact wall and is provided with the first air inlet; The connecting side wall is connected between the contact wall and the outer wall, and is used to enclose the slag cooler cavity together with the contact wall and the outer wall, and is provided with the slag outlet; The spacer is connected between the contact wall and the outer wall.

3. The air-cooled slag cooler according to claim 2, characterized in that: The contact wall is used for connection with the furnace wall of the boiler, and the inner surface of the contact wall is overlapped and connected with the outer surface of the furnace wall of the boiler.

4. The air-cooled slag cooler according to claim 2, characterized in that: Among the contact wall, the outer wall and the connecting side wall, at least the contact wall is a water-cooled wall; at least a portion of the furnace wall of the boiler connected to the contact wall is a water-cooled wall.

5. The air-cooled slag cooler according to claim 2, characterized in that: The air-cooled slag cooler also includes a wear-resistant layer, which is arranged on the inner surfaces of the contact wall, the outer wall, and the connecting side wall; the wear-resistant layer is a non-metallic wear-resistant layer.

6. The air-cooled slag cooler according to claim 2, characterized in that: The connecting side wall includes a first connecting side wall and a second connecting side wall opposite to the first connecting side wall, and the first connecting side wall, the spacer and the second connecting side wall are arranged in sequence along a first preset direction; the first air outlet is arranged at a portion of the contact wall close to the first connecting side wall; the slag inlet is arranged at a portion of the contact wall close to the second connecting side wall; the slag outlet is arranged on the second connecting side wall, and the first air inlet is arranged at a portion of the outer wall close to the second connecting side wall.

7. The air-cooled slag cooler according to claim 6, characterized in that: The connecting side wall includes a third connecting side wall and a fourth connecting side wall opposite to the third connecting side wall, and the third connecting side wall and the fourth connecting side wall are arranged in sequence along a second preset direction; the first part is connected to the third connecting side wall, the second part is connected between the first part and the fourth connecting side wall, and the first air inlet is arranged on the fourth connecting side wall; the slag inlet is arranged on a part of the contact wall close to the third connecting side wall, and the slag outlet is arranged on a part of the second connecting side wall close to the fourth connecting side wall; the slag inlet part extends along a direction perpendicular to the second preset direction, and the cooling part extends along the second preset direction, and the second preset direction is the slag discharge direction.

8. The air-cooled slag cooler according to claim 7, characterized in that: The first part includes a first connecting plate and a second connecting plate, one end of the first connecting plate is connected to the third connecting side wall, one end of the second connecting plate is bent and connected to an end of the first connecting plate away from the third connecting side wall, and the other end of the second connecting plate is bent and connected to the second part; the second part includes a third connecting plate, and the third connecting plate is connected between the second connecting plate and the fourth connecting side wall; the first connecting plate is vertically connected to the third connecting side wall; the first connecting plate is vertically connected to the second connecting plate, and the third connecting plate is vertically connected to the second connecting plate and the fourth connecting side wall, the distance between the first connecting plate and the second connecting side wall is greater than the distance between the third connecting plate and the second connecting side wall, and the end of the second connecting plate away from the first connecting plate protrudes from the third connecting plate, so that the distance between the second connecting plate and the second connecting side wall is smaller than the distance between the third connecting plate and the second connecting side wall.

9. A circulating fluidized bed, characterized in that: The circulating fluidized bed comprises: The air-cooled slag cooler according to any one of claims 1 to 8; A boiler having a boiler wall surrounding a furnace, wherein the boiler wall is provided with a heat exhaust port, a return air port, a slag discharge port and a return material port, wherein the heat exhaust port, the return air port, the slag discharge port and the return material port are respectively connected to the furnace, the slag discharge port is connected to a slag inlet of the air-cooled slag cooler, and the return air port is connected to a first air outlet of the air-cooled slag cooler; A cyclone separator, comprising a shell and a separator body, the shell having a chamber and a second air inlet, a second air outlet and a discharge port connected to the chamber, the separator being located in the chamber, the second air inlet of the cyclone separator being connected to the heat exhaust port of the boiler for receiving the flue gas discharged from the boiler and performing gas-material separation on the flue gas to form fly ash and coarse particles, the separated fly ash being discharged via the second air outlet, and the separated coarse particles being discharged via the discharge port of the cyclone separator; A material return device connected between the material discharge port of the cyclone separator and the material return port of the boiler; The convection air duct is connected to the second air outlet of the cyclone separator and is used for discharging the separated fly ash.

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