CN204345616U - Living beings chain-grate boiler chamber structure - Google Patents

Abstract

The utility model discloses a furnace structure of a biomass chain boiler, which comprises a chain grate. A front arch, a middle arch and a rear arch are sequentially arranged above the chain grate from front to back, and a fuel layer is arranged on the upper side of the chain grate. In the fuel layer area, the middle arch is composed of a vertical flame-refracting wall, the rear arch is composed of a horizontal wall extending front and rear horizontally arranged on the rear side of the bottom of the flame-refracting wall, a vault is provided between the front arch and the middle arch, and the front arch There is a first combustion chamber between the middle arch and the middle arch, and a second combustion chamber is formed between the middle arch, the rear arch and the chain grate. A vertical rear furnace wall is arranged on the rear side of the rear arch. A third combustion chamber is provided between the furnace walls, a flue gas outlet is provided on the rear side of the top of the third combustion chamber, a flue gas outlet is provided on the top of the third combustion chamber, and a gas outlet connected to the second combustion chamber is provided at the bottom of the third combustion chamber. into the smoke port. The utility model relates to a biomass chain boiler furnace structure which can fully burn fuel in the furnace and enhance heat exchange efficiency.

Description

Furnace structure of biomass chain boiler

technical field

The utility model belongs to the field of biomass combustion furnaces, in particular to a furnace structure of a biomass chain boiler.

Background technique

The furnace arch is the furnace wall that protrudes from the inner wall of the furnace, and its form is inclined or horizontal-inclined. The combustible gas produced in the reduction zone and the fuel powder and coke particles brought into the furnace with the air flow are fully mixed with the air under the action of the furnace arch, and burnt out, reducing the loss of gas and solid incomplete combustion and improving combustion efficiency; On the one hand, the furnace arch can reasonably organize the heat radiation and hot flue gas flow in the furnace, so as to ensure that the new fuel can be ignited in time and burn stably. The furnace arch can be divided into the following three types according to the location:

Front arch - located above the front of the fire bed, it plays a role in accelerating the ignition of new fuel, so it is also called ignition arch or radiant arch, with horizontal, inclined and reverse inclined forms. The radiation mode of the front arch is mainly re-radiation and supplemented by mirror reflection. In this way, the radiant heat is transferred to the ignition area of the new fuel, which improves the ignition and burning speed of the fuel.

Middle arch—located above the middle of the firebed, it is short in length, flexible in layout and low in cost, and is generally suitable for boiler renovation.

Back arch - located above the rear of the firebed, there are single-inclined, horizontal-inclined and double-inclined. The main functions of the back arch are as follows:

(1) The throat is formed with the front arch, which can strengthen the air flow disturbance, make the combustibles and air fully mix and facilitate combustion, prolong the stay time of the airflow in the furnace, and is very beneficial to the burnout of combustibles;

(2) A large amount of high-temperature flue gas, hot carbon particles and excess air are transported to the fuel combustion area to further enhance the combustion, and the combustible gas in the furnace space is burned out under the action of oxygen, so the combustion temperature is increased;

(3) The scorching smoke and the fiery red carbon particles entrained are guided to the front end under the action of the rear arch, and are subjected to inertial separation when the airflow turns upward, and the fiery red carbon particles fall to the new fuel layer, which is conducive to ignition and combustion;

(4) It has the function of heat preservation and combustion promotion in the burning area, greatly reducing the physical heat loss of ash and improving the efficiency of the boiler.

Whether the fuel on the fuel bed can be burned strongly and completely depends not only on the appropriate grate visible heat intensity, reasonable furnace arrangement and operation mode, but also depends to a large extent on the geometry and size of the furnace arch. However, most of the existing biomass boilers are reformed from coal-fired boilers. Because the combustion characteristics of biomass briquettes are very different from those of coal, the boilers with conventional furnace arch design have problems when burning biomass briquettes. Some problems: the high-temperature flame cannot stay in the furnace for a sufficient time, and the combustible components cannot be fully mixed with the air, resulting in a high content of carbon monoxide, methane and other combustible gases and solid combustible particles in the flue gas.

Utility model content

The purpose of this utility model is to provide a biomass chain that can fully burn the fuel in the furnace, greatly prolong the residence time of the flue gas in the furnace, fully exchange heat between the high-temperature flue gas and the convective tube bundle, and enhance the heat transfer efficiency Boiler furnace structure.

In order to achieve the above purpose, the utility model adopts the following technical scheme: the furnace structure of the biomass chain boiler includes a chain grate, and the top of the chain grate is provided with a front arch, a middle arch and a rear arch in sequence from front to back, and the upper side of the chain grate is There is a fuel layer area for placing the fuel layer, the middle arch is composed of a vertical flame wall, the rear arch is composed of a transverse wall extending front and rear at the bottom of the flame wall, and there is a wall between the front and middle arches. There is a first combustion chamber between the front arch and the middle arch, a second combustion chamber is formed between the middle arch, the rear arch and the chain grate, and a vertical rear furnace wall is arranged on the rear side of the rear arch. , the rear arch and the rear furnace wall are provided with a third combustion chamber. The flue gas inlet connected to the second combustion chamber; the secondary air outlets on the front arch and the middle arch are respectively provided, the secondary air outlets on the front arch and the secondary air outlets on the middle arch are opposite to each other, and the outlets of the secondary air outlets on the front arch The wind direction points to the fuel layer area on the lower side of the middle part of the first combustion chamber, and the air outlet direction of the secondary air outlet on the middle arch also points to the fuel layer area on the lower side of the middle part of the first combustion chamber. The rear end of the chain grate is located in front of the transverse wall lower side.

There is an arc chamfer between the top front side of the flame breaking wall and the vault, and an arc chamfering on the bottom front side of the flame breaking wall.

The secondary air outlet on the middle arch is set at the bottom circular arc chamfer of the flame folding wall.

The upper part of the front arch extends obliquely upward from the front to the rear, and the lower part extends vertically. The secondary air outlet of the front arch is set on the vertical extension of the front arch.

The flame bending wall extends vertically and the bottom end of the flame bending wall is provided with a backward bending part.

The rear furnace wall is provided with a soot removal port connected to the third combustion chamber, and the outer side of the rear furnace wall is provided with a soot removal door corresponding to the soot removal port.

A primary air box is provided on the lower side of the first combustion chamber.

The biomass chain boiler furnace structure described in the utility model has the following beneficial effects:

1. It has a new furnace arch structure: the furnace adopts a full furnace arch design, the front arch extends to the middle of the furnace, and a flame-folding wall is added as the middle arch, and the first combustion chamber is formed between the front arch, the middle arch and the fire grate. The back arch is a horizontal wall, the back arch, the flame wall and the chain grate form the second combustion chamber, and the smoke enters the third combustion chamber from the smoke inlet between the flame wall and the rear arch. The furnace arch divides the furnace into three areas - the first combustion chamber, the second combustion chamber and the third combustion chamber, which prolongs the residence time of high-temperature flue gas in the furnace and improves the combustion efficiency. The flue gas burns under the action of the primary wind in the first combustion chamber; the primary dust reduction and secondary combustion are carried out in the second combustion chamber; when the flue gas enters the third combustion chamber, the flow velocity decreases, and the flue gas undergoes secondary dust reduction to increase the burning rate. Reduce smoke and dust emissions.

2. It has a new type of secondary air system: the secondary air port located in the front arch is inclined downward to allow the wind to blow to the middle of the fuel layer of the first combustion chamber, and the secondary air port located in the middle arch is inclined forward and downward to allow the wind to blow to the first combustion chamber. In the middle of the fuel layer of the combustor, counter-flow disturbances are formed in the area above the fuel layer. This design prolongs the residence time of high-temperature flue gas in the first combustion chamber, optimizes the thermal field in the furnace at the same time, improves the stable combustion capability of the boiler and the burnout degree of fuel, so that the flame does not stick to the wall, does not rush into the wall, and has a high degree of fullness. Uniform heat load on the wall.

3. The top and bottom of the front side of the arch formed by the flame-folding wall are designed with circular arc chamfering. This design makes the high-temperature flue gas flow more smoothly in the furnace without dead ends, and optimizes the flue gas flow.

4. Set the soot cleaning door on the rear wall of the furnace tail. When the biomass fuel is burned, a small amount of ash will move with the high-temperature flue gas due to its light weight, and finally deposit on the horizontal wall of the rear arch. The deposited ash and smoke It can be removed periodically by the dust removal door.

In the furnace structure of the biomass chain boiler described in the utility model, the biomass fuel enters the first combustion chamber of the furnace along with the movement of the chain grate, and the first combustion chamber is the main combustion area. The material shaped fuel is burned, and the high-temperature flue gas generated is radiated and heat-exchanged in the furnace, and finally bypasses the flame wall and enters the second combustion chamber. The second combustion chamber is the secondary combustion zone, where combustible gases such as carbon monoxide and methane and solid combustible particles contained in the high-temperature flue gas continue to burn and transfer heat, and part of the smoke falls here. The flue gas after the secondary combustion enters the third combustion chamber through the opening between the flame wall and the rear arch. The flue gas further reduces dust in the third combustion chamber, and enters the flue under the action of the induced draft system. The soot particles and ash accumulated in the first combustion chamber and the second combustion chamber in the furnace can be discharged through the grate movement, and the soot particles and ash in the third combustion chamber can be removed through the ash cleaning door.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Detailed ways

The furnace structure of the biomass chain boiler shown in Fig. 1 includes a chain grate 7, and the top of the chain grate 7 is sequentially provided with a front arch 2, a middle arch and a rear arch from front to back.

The upper part of the front arch 2 extends obliquely upward from the front to the rear, and the lower part of the front arch 2 extends vertically.

The middle arch is formed by a vertical flame-breaking wall 5, and the flame-breaking wall 5 extends vertically, and the bottom end of the flame-breaking wall 5 is provided with a backward bending portion.

The rear arch is formed by a horizontal wall 6 extending front and rear and extending horizontally at the rear side of the bottom of the flame breaking wall 5 , and the horizontal wall 6 extends horizontally front and rear. The rear end of the chain grate 7 is positioned at the front lower side of the transverse wall 6 .

The front arch 2, the middle arch and the rear arch are all spaced above the chain grate 7, and the upper side of the chain grate 7 is provided with a fuel layer area 4 for placing a fuel layer. The fuel layer area 4 is a strip-shaped area located on the upper side of the chain grate 7 . A vault 13 is provided between the front arch 2 and the middle arch, and the vault 13 is a partition wall extending horizontally from front to back. An arc chamfer is provided between the top front side of the flame folding wall 5 and the vault 13 , and an arc chamfering is also provided on the bottom front side of the flame folding wall 5 .

A first combustion chamber 14 is arranged between the front arch 2 and the middle arch, and the first combustion chamber 14 is surrounded by the front arch 2, the middle arch and the vault 13 between the front arch 2 and the middle arch. A second combustion chamber 15 is formed between the lower side of the middle arch, the lower side of the rear arch and the chain grate 7 . The rear side of the rear arch is fixed with a vertical rear furnace wall, the top of the rear furnace wall extends to the upper side of the horizontal wall 6, and the bottom end extends to the lower side of the horizontal wall 6. The third combustion chamber 11, that is, the U-shaped area surrounded by the middle arch, the rear arch and the rear furnace wall is the third combustion chamber 11, and the top of the third combustion chamber 11 is provided with front and rear horizontal walls 10 and smoke outlets. Gas port 9, and the flue gas outlet 9 is positioned at the top rear side of the third combustion chamber 11, and the flue gas outlet 9 is the gap between the horizontal wall body 10 and the rear furnace wall top (of course, the utility model is not limited to In the above form, the wall 10 can also cover the top of the entire third combustion chamber 11, and the smoke outlet 9 is opened on the rear side of the wall 10), and the third combustion chamber 11 is provided with the second combustion chamber 15. The smoke inlet 16, the bottom of the middle arch and the front end of the transverse wall 6 are set at intervals, the gap between the bottom of the middle arch and the front end of the transverse wall 6 is the smoke inlet 16, the smoke outlet 9 and the smoke inlet 16 They are respectively located at the top and bottom of the third combustion chamber 11. The flue gas outlet 9 is connected to the flue, and the flue is connected to the air induction system. Under the action of the air induction system, it is convenient to discharge the smoke. Shows.

A primary air box 3 is provided on the lower side of the first combustion chamber 14 . The primary air box 3 can provide primary air, and the primary air box 3 is fixed on the body of heater, and is positioned between the upper and lower chains of the chain fire grate 7. The primary air box 3 is prior art, so it is not described in detail.

The secondary air outlet 1 on the front arch 2 and the middle arch are respectively provided. The secondary air outlet 1 on the front arch 2 and the secondary air outlet 1 on the middle arch are set opposite to each other. On the vertical extension part of the middle arch, the secondary tuyere 1 on the middle arch is set at the bottom arc chamfer of the flame folding wall 5 . The air outlet direction of the secondary air outlet 1 on the front arch 2 is inclined downward to the fuel layer area 4 on the lower side of the middle part of the first combustion chamber 14, and the air outlet direction of the secondary air outlet 1 on the middle arch is also obliquely downward to the first combustion chamber 14 The fuel layer area 4 on the lower side of the middle part. The secondary air outlet 1 is connected to the secondary air supply system, and the secondary air supply system is the prior art, so it will not be described in detail.

The rear furnace wall is provided with a soot removal port connected to the third combustion chamber 11, and a soot removal door 8 is set on the outer side of the rear furnace wall corresponding to the soot removal port.

The biomass chain boiler furnace structure described in the utility model, when working, the fuel layer area 4 places the fuel layer, and the biomass fuel enters the first combustion chamber 14 of the furnace along with the movement of the chain grate 7, and the first combustion chamber 14 is In the main combustion zone, under the primary air and secondary air, the biomass briquette fuel is burned, and the high-temperature flue gas generated is radiated and heat-exchanged in the furnace, and finally bypasses the flame breaking wall 5 and enters the second combustion chamber 15 . The second combustion chamber 15 is a secondary combustion zone, where combustible gases such as carbon monoxide and methane and solid combustible particles contained in the high-temperature flue gas continue to burn and transfer heat, and part of the smoke falls here. The flue gas after secondary combustion enters the third combustion chamber 11 through the opening between the flame wall 5 and the rear arch. The flue gas further reduces dust in the third combustion chamber 11, and enters the flue under the action of the induced draft system. The soot particles and ash accumulated in the first combustion chamber 14 and the second combustion chamber 15 in the furnace can be discharged through the grate movement, and the soot particles and ash in the third combustion chamber 11 can be removed through the ash cleaning door 8 . The smoke flow direction line 12 first flows in an arched shape in the first combustion chamber 14, then bypasses the second combustion chamber 15, then bypasses the bottom end of the flame breaking wall 5 and enters the third combustion chamber 11, and then passes through the smoke outlet 9 is discharged, and the entire smoke flow direction line 12 is wavy.

Claims (7)

1. The furnace structure of the biomass chain boiler, including the chain grate, is characterized in that: the top of the chain grate is provided with a front arch, a middle arch and a rear arch in sequence from front to back, and the upper side of the chain grate is provided with a fuel layer. In the fuel layer area, the middle arch is formed by the vertical flame wall, and the back arch is formed by the horizontal wall extending front and rear at the bottom of the flame wall. There is a vault between the front arch and the middle arch. There is a first combustion chamber between the arches, a second combustion chamber is formed between the middle arch, the rear arch and the chain grate, and a vertical rear furnace wall is provided on the rear side of the rear arch, and the middle arch, rear arch and rear furnace wall There is a third combustion chamber between them, the rear side of the top of the third combustion chamber is provided with a smoke outlet, the top of the third combustion chamber is provided with a smoke outlet, and the bottom of the third combustion chamber is provided with a smoke inlet connected to the second combustion chamber. Air port: There are secondary air ports on the front arch and the middle arch respectively, the secondary air ports on the front arch and the secondary air ports on the middle arch are opposite to each other, and the air outlet direction of the secondary air port on the front arch points to the first combustion chamber The fuel layer area on the lower side of the middle part, the air outlet direction of the secondary air outlet on the middle arch also points to the fuel layer area on the lower side of the middle part of the first combustion chamber, and the rear end of the chain grate is located on the lower side of the front part of the transverse wall. 2. The furnace structure of a biomass chain boiler as claimed in claim 1, characterized in that: an arc chamfer is provided between the front side of the top of the flame-folding wall and the vault, and an arc chamfer is provided on the front side of the bottom end of the flame-folding wall. There are arc chamfers. 3. The furnace structure of the biomass chain boiler according to claim 2, characterized in that: the secondary tuyeres on the middle arch are arranged at the circular arc chamfers at the bottom of the flame breaking wall. 4. The furnace structure of the biomass chain boiler according to claim 1, characterized in that: the upper part of the front arch extends obliquely upward from the front to the rear, and the lower part extends vertically, and the secondary air outlet of the front arch is arranged in the vertical direction of the front arch. on the extension. 5 . The furnace structure of the biomass chain boiler according to claim 1 , characterized in that: the folded flame wall extends vertically and the bottom end of the folded flame wall is provided with a backward bending portion. 6 . 6. The furnace structure of the biomass chain boiler according to claim 1, characterized in that: the rear furnace wall is provided with a soot removal port connected with the third combustion chamber, and the outer side of the rear furnace wall is provided corresponding to the soot removal port Clear the door. 7. The furnace structure of the biomass chain boiler according to claim 1, characterized in that: a primary air box is provided on the lower side of the first combustion chamber.