CN114738720A

CN114738720A - Smoke circulating reciprocating grate combustion biomass steam boiler

Info

Publication number: CN114738720A
Application number: CN202210397110.0A
Authority: CN
Inventors: 曹希新; 刘新龙; 邹友民; 刘红斌; 娄经松
Original assignee: Hunan Chang Hong Boiler Technology Co ltd
Current assignee: Hunan Chang Hong Boiler Technology Co ltd
Priority date: 2022-04-15
Filing date: 2022-04-15
Publication date: 2022-07-12

Abstract

A flue gas circulation type reciprocating grate biomass-fired steam boiler comprises a boiler body, wherein a hearth is arranged in the boiler body, the hearth is connected with an exhaust passage, a reciprocating grate used for conveying biomass fuel is arranged in the hearth, a first air preheater and a second air preheater are arranged on the exhaust passage, air is introduced through a primary air channel and is preheated by the first air preheater and then sent to the reciprocating grate to promote combustion of the biomass fuel, and air is introduced through a secondary air channel and is preheated by the second air preheater and then sent to high-temperature disturbance flue gas inside the hearth. The invention can avoid the insufficient combustion of the biomass fuel and reduce the pollutant content of the discharged tail gas.

Description

Smoke circulating reciprocating grate combustion biomass steam boiler

Technical Field

The invention relates to the technical field of biomass-fired boilers, in particular to a smoke-circulating reciprocating grate biomass-fired steam boiler.

Background

The biomass boiler is characterized in that biomass is used as fuel. The biomass fuel can effectively utilize biomass as fuel, can reduce pollution and effectively utilize residual energy.

The heat loss of the boiler exhaust smoke is the largest heat loss of the boiler, and the higher the exhaust smoke temperature is, the larger the heat loss of the boiler is. The traditional boiler generally adopts an energy saver to reduce the temperature of exhaust smoke, and then cold air is input into a hearth by arranging an air blower, so that sufficient oxygen is provided for the combustion of the boiler. However, a large amount of cold air enters the hearth, which reduces the temperature in the hearth, aggravates the incomplete combustion of fuel, causes a large amount of fuel waste, and increases the content of discharged tail gas pollutants.

Disclosure of Invention

The invention aims to provide a flue gas circulating type reciprocating furnace combustion biomass steam boiler, which is used for avoiding insufficient combustion of biomass fuel and reducing the pollutant content of exhaust gas.

In order to solve the technical problems, the invention adopts the following technical scheme: the utility model provides a circulating reciprocating grate of flue gas fires biomass steam boiler, includes the boiler body, this internal furnace and the furnace that is provided with of boiler are connected with exhaust passage, be provided with the reciprocating grate who is used for carrying biomass fuel in the furnace, be provided with first air heater and second air heater on the exhaust passage, let in air and send to reciprocating grate promotion biomass fuel burning after preheating through setting up the primary air duct, let in air and send to the inside disturbance high temperature flue gas of furnace after preheating through setting up the secondary air duct and passing through second air heater.

Preferably, a plurality of air chambers are arranged in the hearth below the reciprocating grate, the primary air channel is communicated with each air chamber, and a feeding hole is formed in one end of the reciprocating grate.

More preferably, the plurality of plenums are arranged along the length of the reciprocating grate.

More preferably, one end of the exhaust channel is connected with the upper part of the hearth, and the other end of the exhaust channel extends vertically downwards and then is connected to an exhaust chimney through a dust remover and an induced draft fan.

More preferably, the first and second air preheaters are disposed in a vertical section of the exhaust gas passageway, and the first air preheater is located above the second air preheater.

More preferably, the first air preheater comprises a pipe box arranged in the exhaust passage and a U-shaped pipe arranged in the pipe box, an air inlet pipe orifice of the U-shaped pipe is located below an air outlet pipe orifice, a pipe body at an air outlet end of the U-shaped pipe is branched to form two air outlet pipe orifices, the two air outlet pipe orifices are respectively connected with a primary air duct, the two primary air ducts respectively extend to the front side and the rear side of the boiler body, and the air inlet pipe orifice of the U-shaped pipe is connected to the air blower through a pipeline.

More preferably, still be provided with the economizer on the exhaust passage, the boiler body is connected with the inlet tube, the inlet tube communicates with the economizer so that carry out the heat exchange with the flue gas.

More preferably, the economizer comprises upper and lower two-stage economizers arranged in series in the vertical section of the exhaust gas passage and above the first air preheater.

More preferably, a valve for adjusting the air volume is arranged on the secondary air duct, and the secondary air duct is provided with a plurality of nozzles for injecting air flow into the furnace.

More preferably, the plurality of nozzles are respectively arranged at the front side and the rear side of the furnace according to a certain number and arrangement.

The invention has the beneficial effects that: blow to reciprocating grate after preheating the air through first air heater, can improve the furnace internal temperature and make biomass fuel change the burning, biomass boiler's combustion efficiency has been improved, it is more abundant to make biomass fuel burning, blow to the interior disturbance high temperature flue gas of furnace after preheating the air through second air heater for the volatile components that biomass fuel drying and cracking produced can burn completely, and consume abundant oxygen in order to prevent a large amount of black smoke and produce, reduce the pollutant content of emission tail gas.

Drawings

FIG. 1 is a schematic overall structure diagram in an embodiment of the present invention;

FIG. 2 is a schematic top view of the overall structure of the embodiment;

FIG. 3 is a schematic structural diagram of a first air preheater in an embodiment;

FIG. 4 is a schematic diagram of the left side structure of the first air preheater in the embodiment.

The reference signs are:

1-boiler body 2-hearth 3-reciprocating grate

4-exhaust gas channel 5-first air preheater 5 a-tube box

6-second air preheater 7-primary air duct 8-secondary air duct

9-wind chamber 10-energy-saving device.

Detailed Description

In order to facilitate understanding of those skilled in the art, the present invention is further described below with reference to the following examples and the accompanying drawings, which are not intended to limit the present invention.

It should be noted that, unless otherwise explicitly stated or limited, terms such as "mounted," "connected," "fixed," and the like are to be construed broadly and include, for example, fixed connections, detachable connections, or integral connections. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations. Further, in the present invention, unless otherwise expressly specified or limited, the first feature "on" or "under" the second feature may comprise the first and second features being in direct contact, or may comprise the first and second features being in contact, not in direct contact, but via another feature in between.

As shown in fig. 1-2, flue gas circulation formula reciprocating grate fires biomass steam boiler, including boiler body 1, be provided with furnace 2 in the boiler body 1 and furnace 2 is connected with exhaust passage 4, be provided with reciprocating grate 3 that is used for carrying biomass fuel in the furnace 2, be provided with first air heater 5 and second air heater 6 on the exhaust passage 4, through setting up primary air duct 7 and let in the air and send to reciprocating grate 3 after preheating through first air heater 5 and promote biomass fuel to burn, through setting up secondary air duct 8 and let in the air and send to the inside disturbance high temperature flue gas of furnace 2 after preheating through second air heater 6.

The hearth below the reciprocating grate 3 is provided with a plurality of air chambers 9, the primary air channel 7 is communicated with each air chamber 9, so that a certain number of air chambers can be opened according to actual needs to improve the full combustion degree of fuel, or the primary air quantity can be timely, sectionally, reasonably and effectively supplemented according to the characteristics of biomass fuel forming combustion, and one end of the reciprocating grate 3 is provided with a feeding hole.

Preferably, a plurality of plenums 9 are arranged along the length of the reciprocating grate 3 so that the reciprocating grate 3 can be fully flooded with preheated air.

More preferably, one end of the exhaust duct 4 is connected to the upper part of the furnace 2, and the other end is connected to an exhaust stack (not shown in the drawings) through a dust collector and an induced draft fan after extending vertically downward.

Wherein the first air preheater 5 and the second air preheater 6 are disposed at the vertical section of the exhaust gas passage 4, and the first air preheater 5 is located above the second air preheater 6.

Further, as shown in fig. 3-4, the first air preheater 5 includes a tube box 5a disposed in the exhaust channel 4 and a U-shaped tube disposed in the tube box 5a, an air inlet of the U-shaped tube is located below an air outlet, and a tube body of an air outlet end of the U-shaped tube is bifurcated to form two air outlets, the two air outlets are respectively connected with a primary air duct 7, the two primary air ducts 7 respectively extend to the front side and the rear side of the boiler body 1, and the air inlet of the U-shaped tube is connected to the blower through a pipeline. This first air heater 5 adopts two return stroke structural style of going into from top to bottom and going out, one advances two, and the same direction that also is flowing with the flue gas forms conversely, simple structure, and the heated area is big, can effectively reduce exhaust gas temperature, and energy-conserving effect is more showing.

Still further, still be provided with economizer 10 on the exhaust passage 4, boiler body 1 is connected with the inlet tube, and the inlet tube communicates with economizer 10 in order to be used for carrying out the heat exchange with the flue gas.

The economizer 10 comprises an upper economizer and a lower economizer, the two economizers are arranged in series in the vertical section of the exhaust passage 4 and above the first air preheater 5, and the structure is compact. Wherein, the main structure of the economizer 10 comprises water pipes arranged from bottom to top along the vertical exhaust passage 4, so that the path for conveying water is opposite to the path for flue gas flowing, thereby improving the heat exchange effect, ensuring that the water is preheated more fully and the temperature of the flue gas is reduced more remarkably.

In this embodiment, the secondary air duct 8 is provided with a valve for adjusting the air volume, and the secondary air duct 8 is provided with a plurality of nozzles for injecting air into the furnace 2. And, a plurality of nozzles are respectively arranged at the front and rear sides of the furnace 2 according to a certain number and arrangement.

When the biomass steam boiler with the smoke circulating type reciprocating grate combustion provided by the embodiment works, firstly, biomass fuel enters the reciprocating grate 3 through the feeding hole and is conveyed downwards step by step, a burner capable of igniting the biomass fuel is arranged on one side of the reciprocating grate 3, during the combustion process, an air blower sends air into a primary air channel 7 and exchanges heat with the smoke through a first air preheater 5 so as to realize preheating, then the air is blown to each air chamber 9 along the primary air channel 7 and ascends to the reciprocating grate 3 from the air chamber 9 to be contacted with the biomass fuel, the combustion efficiency of the biomass fuel is improved, the biomass fuel is combusted more fully, meanwhile, the air blower sends air into a secondary air channel 8 and exchanges heat with the smoke through a second air preheater 6 so as to realize preheating, then the air flows to each nozzle along the secondary air channel 8 and is sprayed out from the nozzle to the hearth 2, therefore, high-temperature flue gas in the hearth 2 is disturbed, volatile components generated by drying and cracking of the biomass fuel can be completely combusted and burnt out, enough oxygen is consumed to prevent a large amount of black smoke from being generated, the pollutant content of the discharged tail gas is reduced, and the production cost is saved.

It should be known to those skilled in the art that the inside of the boiler body 1 above the furnace 2 is a container for containing water for burning to generate high-temperature steam, and since this part is the prior art, it has been omitted in the description of this embodiment, but the input pipeline connected to the container can be connected to the economizer 10 to make water firstly pass through the economizer 10 to exchange heat with high-temperature flue gas and then enter the container, so as to fully utilize the heat of the flue gas, so that the water can have a certain temperature in advance, and the effects of saving energy and recycling flue gas are achieved. And the flue gas after the heat exchange is carried out with water through the energy-saving appliance 10 flows down again, and then carries out the heat exchange with first air heater 5 and second air heater 6, preheats the air to further make full use of the preheating of discharging the flue gas, the maximize cyclic utilization the heat energy of flue gas, practiced thrift the energy, improved the thermal efficiency of boiler, also make simultaneously finally the flue gas heat that discharges out can reduce.

While the foregoing embodiments are illustrative of the preferred embodiments of the invention, the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is not limited thereto.

Claims

1. Flue gas circulation formula reciprocating grate fires biomass steam boiler, including boiler body (1), be provided with furnace (2) and furnace (2) in boiler body (1) and be connected with exhaust passage (4), its characterized in that: be provided with in furnace (2) and be used for carrying biomass fuel's reciprocal grate (3), be provided with first air heater (5) and second air heater (6) on exhaust passage (4), let in the air and send to reciprocal grate (3) after preheating through first air heater (5) and promote biomass fuel burning through setting up primary air duct (7), let in the air and send to furnace (2) inside disturbance high temperature flue gas through setting up secondary air duct (8) and after preheating through second air heater (6).

2. The flue gas circulating reciprocating grate combustion biomass steam boiler according to claim 1, characterized in that: the hearth below the reciprocating grate (3) is provided with a plurality of air chambers (9), the primary air channel (7) is communicated with each air chamber (9), and one end of the reciprocating grate (3) is provided with a feeding hole.

3. The flue gas circulating reciprocating grate combustion biomass steam boiler according to claim 2, characterized in that: a plurality of air chambers (9) are arranged along the length direction of the reciprocating grate (3).

4. The flue gas circulating reciprocating grate combustion biomass steam boiler according to claim 1, characterized in that: one end of the exhaust channel (4) is connected with the upper part of the hearth (2), and the other end of the exhaust channel extends vertically downwards and then is connected to an exhaust chimney through a dust remover and an induced draft fan.

5. The flue gas circulating reciprocating grate combustion biomass steam boiler according to claim 4, characterized in that: the first air preheater (5) and the second air preheater (6) are arranged in the vertical section of the exhaust gas channel (4), and the first air preheater (5) is located above the second air preheater (6).

6. The flue gas circulating reciprocating grate combustion biomass steam boiler according to claim 5, characterized in that: the first air preheater (5) comprises a pipe box (5 a) arranged in the exhaust channel (4) and a U-shaped pipe arranged in the pipe box (5 a), an air inlet pipe orifice of the U-shaped pipe is located below an air outlet pipe orifice, the pipe body of the air outlet end of the U-shaped pipe is forked to form two air outlet pipe orifices, the two air outlet pipe orifices are respectively connected with a primary air channel (7), the two primary air channels (7) respectively extend to the front side and the rear side of the boiler body (1), and the air inlet pipe orifice of the U-shaped pipe is connected to an air blower through a pipeline.

7. The flue gas circulating reciprocating grate combustion biomass steam boiler according to claim 4, characterized in that: still be provided with energy-saving appliance (10) on exhaust passage (4), boiler body (1) is connected with the inlet tube, the inlet tube communicates with energy-saving appliance (10) in order to be used for carrying out the heat exchange with the flue gas.

8. The flue gas circulating reciprocating grate combustion biomass steam boiler according to claim 7, characterized in that: the economizer (10) comprises an upper two-stage economizer and a lower two-stage economizer, and the two-stage economizers are arranged in series in the vertical section of the exhaust passage (4) and above the first air preheater (5).

9. The flue gas circulating reciprocating grate combustion biomass steam boiler according to claim 4, characterized in that: the secondary air duct (8) is provided with a valve for adjusting the air quantity, and the secondary air duct (8) is provided with a plurality of nozzles for jetting air flow into the hearth (2).

10. The flue gas circulating reciprocating grate combustion biomass steam boiler of claim 9, characterized in that: the plurality of nozzles are respectively arranged on the front side and the rear side of the hearth (2) according to a certain number and arrangement.