CN2286282Y

CN2286282Y - Travelling grate stoker and pulverized-fuel complex combustion boiler

Info

Publication number: CN2286282Y
Application number: CN 97210686
Authority: CN
Inventors: 潘名麟
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-02-01
Filing date: 1997-02-01
Publication date: 1998-07-15
Anticipated expiration: 2007-02-01

Abstract

The utility model provides a chain fire grate and coal powder complex burning boiler, which mainly solves the problems of poor burning of chain boilers, low loading of coal powder boilers, unstable burning, etc. The main structure of the utility model is that a chain fire grate is arranged at lower part of a boiler chamber, a coal powder burner is arranged above the fire grate, and the utility model adopts a direct blowing powder producing system of a fan coal grinding machine. The fire grate and the coal powder can mutually assist in burning process, so the utility model has the advantages of high boiler chamber temperature, large heat strength, double adaptability to loading change and coal type change at the same time, and the utility model has strong inferior coal burning ability and can keep the boiler running with high output and high efficiency.

Description

Traveling-grate stoker adds the coal dust combined combustion boiler

The utility model relates to a kind of novel coal boiler, and particularly a kind of traveling-grate stoker adds the coal dust combined combustion boiler.

Chain grate boiler is the main type of furnace in the industrial boilers in China, its combustion process is: coal drops on the fire grate front end that constantly slowly moves from front to back by coal bunker, and enter burner hearth along with the motion backward of fire grate, carry out preheating and drying, destructive distillation in the process of in stove, advancing successively, fire burns and burn, discharge slag at last.

The advantage of this boiler is simple in structure, and is easy to operate, and Load Regulation is flexible, but intermittent duty.Shortcoming is that blockiness burning and fuel bed can not self disturbances in combustion process, and calorific intensity is low, burning velocity is slow, and coal is difficult to accomplish completing combustion in stove, and undercapacity, the thermal efficiency is on the low side; In addition, coal is that single face ignites on traveling-grate stoker, and ignition condition is bad, coal adaptability is poor, and when the coal variation, when ature of coal descends, the boiler operatiopn operating mode promptly can worsen rapidly, cause exerting oneself and the thermal efficiency descends significantly, even be difficult to catch fire and move because of the low coal of furnace temperature.Another shortcoming of chain furnace is a fire grate length because of the difficulty on structure and the intensity can not oversize (being no more than 8M), and the uneven burning of the wide cloth wind of fire grate is bad, makes boiler capacity be subjected to certain restriction, and the heap(ed) capacity of chain furnace is 35T/H at present.

Another kind of coal-burning boiler is a coal-powder boiler, and its burning feature is: coal by pulverize, sprays into furnace cavity with air in coal pulverizer, descending fire burns at suspended state.Its advantage is that coal adaptability is wide, and burning is fierce, fire box temperature height, thermal efficiency height; Shortcoming is that equipment investment is big, load adaptability is poor, is difficult to smooth combustion under underload, is only applicable to large medium-size boiler, and is inapplicable on miniature boiler.

At some above-mentioned shortcomings, some improved technical schemes are also arranged at present, there are following two kinds preferably.A kind of is to improve furnace arch structure, and its major technique feature is: the rear arch lengthening is forced down, and face arch is raised, and dwindles the burner hearth throat section, makes the flame reach on the fire grate, and the furnace front temperature raises.Its advantage is to help to improve coal adaptability to a certain extent, improves to catch fire and burning condition, and the retrofit work amount is little, cost is low; Shortcoming is that these measures design at a certain fixedly coal, has certain limitation, and compliance is poor, and the amplitude that the boiler output and the thermal efficiency improve is not obvious, can not tackle the problem at its root.

Another kind is a Chinese patent (application number: 94214484.8) just changeing the chain-grate boiler coal feeder, its major technique feature is the layering coal supply apparatus of installing in former coal bunker position by quantitative feeder and size consist one, make coal layering reorganization, loose being evenly distributed on the fire grate, the coal grain is big down little, and ventilation condition is improved.Its advantage is to have improved efficiency of combustion and boiler output to a certain extent, has strengthened coal adaptability, and the retrofit work amount is little, cost is low; Shortcoming is that the amplitude that improves of boiler output and the thermal efficiency is little, and actual exerting oneself can be improved 20--30% when ature of coal was better, and it is little that coal adaptability changes amplitude, is unsuitable for using that difficulty is caught fire, the colm of difficult after-flame.

The purpose of this utility model is, provides a kind of traveling-grate stoker to add the coal dust combined combustion boiler, and it can make the steam boiler capacity reach 6--120 T/H scope, and the hot-water boiler capacity reaches the 4.2--58MW scope.And have the fire box temperature height, calorific intensity is big, has the double adaptability that load variations and coal are changed simultaneously, and is strong to the burning inferior coal ability especially, the characteristics of aspects such as efficiency of combustion height.

The utility model is achieved in that and is about to fire grate layer combustion and the optimum organization of coal dust suspension combustion that lower furnace portion arranges that traveling-grate stoker carries out layer combustion; Both walls or front and back arch place arrange coal burner above fire grate in addition, a part of coal dust is sprayed into burner hearth carry out suspension combustion.Fire grate and coal dust are auxiliary each other in combustion process, maximize favourable factors and minimize unfavourable ones.Coal dust is by the flame ignition on the fire grate, and the thermal-flame that coal dust firing forms provides abundant thermal source for the coal seam on the fire grate catches fire on the one hand, make difficulty catch fire the colm of difficult after-flame can be smooth on fire grate fire burns, widened coal adaptability; On the other hand coal dust firing can disturbance gas stream in the stove, strengthen mutual mixing, reasonably organize flowing of interior heat radiation of stove and hot flue gas, improve burning velocity and completing combustion degree, combustion process is strengthened, combustion intensity increases, and the radiant heat transfer of heating surface and convection heat transfer' heat-transfer by convection ability strengthen, and the boiler output and the thermal efficiency are greatly improved.In addition, the grate of smooth combustion is the reliable thermal source that breeze airflow catches fire, can guarantee coal dust under the situation of no special igniter in time stably fire burns, so just can avoid underload or, make coal dust firing have security reliability preferably because of misoperation and the unexpected coal dust deflagration accident having that has a power failure and cause.

The utility model has the advantages that:

1, exert oneself big, the thermal efficiency is high

Change traveling-grate stoker into from the chain furnace of fallback and add the coal dust combined combustion boiler, actual exerting oneself can be improved 0.5--1 doubly, and the thermal efficiency improves 10--20%, and the thermal efficiency is up to 75--80%, and 20--30% economizes on coal.

Newly-designed combined combustion boiler, the reason coal changes during operation, ature of coal descends and too much influence exert oneself, boiler output can guarantee that substantially the thermal efficiency can reach 80--85%.

2, coal adaptability is wide

This kind boiler can not only use high-quality bituminous coal, and can burning high-moisture the lower meager coal of high-ash brown coal, bituminous coal and volatile matter, anthracite etc., coal adaptability is wide.

3, load variations adaptability is strong

Can change the method for operation at any time according to payload during this kind boiler operatiopn, load hour is used fire grate separately, loads and adds coal dust when big at any time.Load adjustment amplitude is big, and speed is fast, and blowing out temporarily, banking fire.

4, cost is low

The fire box temperature height of this kind boiler, calorific intensity is big, and grate area and furnace volume heat release rate are all than other grate firing boiler height.When the new combined combustion boiler of design, to compare with the capacity layer burner with other, furnace volume and grate area are little, and heating surface is arranged few, adds the coal pulverizer and the pulverized coal system expense of increase, and comprehensive cost is lower.

5, compatibilization ability is big

Because stove of combined combustion boiler possesses two kinds of combustion apparatus simultaneously, existing fire grate has coal dust again, though newly-designed boiler fire grate thermic load is subjected to certain restriction, but can increase a part of coal dust thermic load, coal dust heat load adjustment ability is bigger, and the coal-fired ratio of coal dust can reach 50--60%, at corresponding increase combustion space, under the reasonable Arrangement heating surface situation, the heap(ed) capacity of this kind boiler is that steam boiler is 120T/H, and hot-water boiler is 58MW.

Description of drawings:

Fig. 1 is the utility model structural representation

Fig. 2 is that the burner side wall is to the spray layout drawing

Fig. 3 is the A--A profile of Fig. 2

Fig. 4 sprays layout drawing for behind the burner front wall

Fig. 5 is the A--A profile of Fig. 4

Fig. 6 sprays layout drawing before the wall behind the burner

Fig. 7 is the A--A profile of Fig. 6

Describe embodiment of the present utility model in detail below in conjunction with accompanying drawing

Basic structure of the present utility model is made up of chain furnace, coal burner and blower mill unit pulverized-coal system.Fire grate and powder process are with a coal shared coal bin 1 in the ordinary course of things, coal in the coal bunker is divided into two-way, one route coal drop is delivered to and is carried out layer combustion on the fire grate 2, another route coal spout is fallen coal in the feeder 12, feeder is adjusted coal-supplying amount according to load, equably coal is sent in the blower mill 3.Blower mill also plays the effect of row's powder except that undertaking the coal-grinding effect, it can produce certain pressure head, in order to overcome the resistance of pulverized coal channel 5 and burner.The drying of coal adopts high-temperature flue gas or hot blast as drier, and high-temperature flue gas connects from upper furnace, enters coal pulverizer 3 and mixes with the part air by smoke extracting tube 8, as a wind.Coal by the shock plate bump powdered of high speed rotating, enters the mill separator 4 on coal pulverizer top then with air-flow in coal pulverizer, fine powder enters burner 6 after being blown to pulverized coal channel 5, and the meal of separating returns coal pulverizer again and refaces.Fire grate and coal dust have an air blast, cold air in the air blast suction chamber, and cold air is divided into two-way after air preheater 9 preheatings, and one the tunnel blows for fire grate through fire grate ajutage 10, and another road is through burner ajutage 11, as secondary wind.Coal dust sprays in the stove from the burner middle part with a wind, rationally mixes with the secondary wind that sprays in the stove by the burner outside, forms the high temperature pulverized coal flame above grate.Flue gas behind fire grate and the coal dust firing enters flue behind convection bank 7, economizer 13, air preheater 9 and slot type inertial dust separator 14, pass through secondary ash collector again, enters chimney by air-introduced machine at last.The coal dust ash part in afterburnt is discharged through deduster with flue gas, and all the other drop on the fire grate and discharge simultaneously with the fire grate lime-ash.

Blower mill is the key equipment in the combined combustion boiler, and its capacity should be determined according to ature of coal and combustion conditions that boiler uses.When the ature of coal that uses better, actual exerting oneself when reaching the 60--70% of nominal output, the coal pulverizer capacity generally must not surpass 30% of the total Coal-fired capacity of boiler.If when using many ash contents, juicy colm or wanting boiler to exceed the power operation, the coal pulverizer capacity can suitably strengthen.Coal pulverizer and boiler are supporting separately, and a stove is joined a machine, and pulverized coal preparation system adopts direct-firing.

The pattern of coal burner has two kinds of spiral-flow type and single flow, and its type selecting and arrangement are determined according to furnace type structure and field condition.When combustion space is bigger, adopt vortex burners when adopting side wall that spray is arranged more; Less when combustion space, adopt parallel flow burners when spray is arranged before spray or the rear arch behind the employing face arch more.

The arrangement of coal burner mainly contains following three kinds:

1, side wall is arranged spray: coal burner (6) is installed on the both walls of burner hearth, the thermal-flame district, middle part of arch horizontal range (aditus laryngis) before and after particular location is generally, and highly apart from grate surface 0.5--1.5M, and to the centroclinal 10--15 of fire grate °.Be adapted to SHL type double-barrel transverse formula chain furnace, steam boiler capacity 6--120T/H, hot-water boiler capacity 4.2--58MW.

2, spray is arranged behind the face arch: coal burner is installed on the boiler face arch, setting height(from bottom) is apart from grate surface 0.5--1.5M, breeze airflow sprays to fire grate thermal-flame district, apart from coal flashboard horizontal range 1--2M, be applicable to two drum longitudinal chain-grate boilers of SZL type and DZL type list drum longitudinal chain-grate boiler, the steam boiler capacity is 4--10T/H, and the hot-water boiler capacity is 2.8--7MW.

3, spray is arranged before the rear arch: coal burner is installed on the boiler rear arch, the height of installing sprays to fire grate thermal-flame district apart from grate surface 1--1.5M with breeze airflow, is applicable to the two drum longitudinal chain furnaces of SZL type, steam boiler capacity 4--10T/H, hot-water boiler capacity 2.8--7MW.

Claims

1, a kind of traveling-grate stoker adds the coal dust combined combustion boiler, comprise body of heater, traveling-grate stoker, air feed system, smoke evacuation system, powder process mechanism, it is characterized in that:, arrange burner (6) at the top both walls or the front and back arch place of fire grate (2) at the lower disposed traveling-grate stoker (2) of burner hearth.

2, combined combustion boiler according to claim 1 is characterized in that, blower mill (3) adopts direct-firing, links to each other with burner (6) by pulverized coal channel (5), joins at the below and the smoke extracting tube (8) of supply blower mill with the feeder (12) of coal.

3, combined combustion boiler according to claim 1 is characterized in that, air blast links to each other with preheater (9), and preheater is connected with burner ajutage (11) with fire grate ajutage (10) simultaneously.

4, combined combustion boiler according to claim 1 is characterized in that, coal burner (6) is installed on the both walls of burner hearth, and the thermal-flame district, middle part of aditus laryngis is apart from grate surface 0.5--1.5M, to the centroclinal 10--15 degree of fire grate.

5, combined combustion boiler according to claim 1 is characterized in that, coal burner (6) is installed on the boiler face arch, apart from grate surface 0.5--1.5M, apart from coal flashboard horizontal range 1--2M.

6, combined combustion boiler according to claim 1 is characterized in that, coal burner (6) is installed on the boiler rear arch, and height is apart from grate surface 1--1.5M.

According to claim 4 or 5 or 6 described combined combustion boilers, it is characterized in that 7, burner (6) is single flow or spiral-flow type.