CN212157144U

CN212157144U - Biomass low-nitrogen gasification device

Info

Publication number: CN212157144U
Application number: CN201921271979.0U
Authority: CN
Inventors: 刘效洲; 赵荣; 薛克书
Original assignee: Guangdong University of Technology
Current assignee: Guangdong University of Technology
Priority date: 2019-08-07
Filing date: 2019-08-07
Publication date: 2020-12-15
Anticipated expiration: 2029-08-07

Abstract

The utility model discloses a biomass low-nitrogen gasification device, which comprises a gasification furnace, a burner and a boiler, wherein the gas outlet of the gasification furnace is connected with the fuel inlet of the burner through a pipeline, the burner is installed on the boiler, and the boiler is provided with two smoke outlets which are sequentially connected with the smoke side of two regenerative heat exchangers and a chimney through pipelines; the preheating air pipes are respectively connected with the air sides of the two regenerative heat exchangers and then respectively connected with the auxiliary mixing chamber, the auxiliary mixing chamber is provided with a first outlet connected with a first inlet of the mixer, the auxiliary mixing chamber is provided with a second outlet connected with a high-temperature air inlet of the gasification furnace and a second inlet of combustion air of the combustor, and the outlet of the mixer is connected with a first inlet of the combustion air of the combustor; the chimney is connected with the flue gas inlet of the gasification furnace and the second inlet of the mixer through a pipeline and a fan. The utility model has the advantages that: the energy is effectively saved, and the conversion rate of the biomass gas is improved and can reach 70-78%; the combustion is sufficient, the NOx emission can be effectively reduced, and the NOx emission can be controlled to be 80-150 mg.

Description

Biomass low-nitrogen gasification device

Technical Field

The utility model belongs to the technical field of biomass gasification stove and boiler system and specifically relates to a low nitrogen gasification of living beings device.

Background

The environmental problems caused by the increasing shortage of fossil fuels are becoming more severe, and biological energy is gaining attention as one of the alternative energy sources. Biomass has unique advantages: renewability, low pollution, wide distribution and rich total amount. The development and utilization of clean energy resources such as biomass energy and the like which are environment-friendly, renewable and rich in resources are the main strategic measures for solving the shortage of petroleum and coal in China, ensuring the national energy safety, protecting the ecological environment and improving the sustainable development capability of China.

The biological energy has high oxygen content, low sulfur content, low ash content and low emission concentration of sulfur oxides and nitrogen oxides after combustion. Although the content of N in biomass is less than that of coal, the content of N in biomass is on the same order of magnitude as that of coal due to the low calorific value of biomass, and the emission of nitrogen oxides from the combustion products of biomass is not insignificant.

At present, biomass fuel has two combustion modes in a heat supply system: one method adopts a biomass boiler to directly burn; the other is gasification post-combustion. The direct combustion causes the dust and NOx to be far beyond the standard due to the problem of the structure of the boiler body, so that the environmental-friendly emission requirement cannot be met; the method of combustion after gasification also has the problems of low gasification rate (generally lower than 60%), serious NOx exceeding standard and the like, and needs to be improved urgently. At present, the combustion is mostly carried out by adopting a mode of gasification and then transportation, but the process is more complex, the investment is larger, and the problems of lower gasification rate, serious NOx standard exceeding and the like exist.

SUMMERY OF THE UTILITY MODEL

The utility model aims at the above not enough that current gasification exists provides one kind and can improve living beings gas conversion rate, effectively reduces the low nitrogen gasification device of living beings that NOx discharged.

In order to achieve the above object, the present invention provides the following technical solutions: a biomass low-nitrogen gasification device comprises a gasification furnace, a combustor and a boiler, wherein a gas outlet of the gasification furnace is connected with a fuel inlet of the combustor through a pipeline, the combustor is arranged on the boiler, the boiler is provided with two smoke outlets which are respectively connected with a smoke side inlet of a heat accumulating type heat exchanger, a smoke side outlet of the heat accumulating type heat exchanger is connected with a chimney through a pipeline, and smoke is discharged through the chimney; the preheating air pipes are respectively connected with air side interfaces of the two regenerative heat exchangers and then respectively connected with an auxiliary mixing chamber, the auxiliary mixing chamber is provided with a first outlet connected with a first inlet of a mixer, the auxiliary mixing chamber is provided with a second outlet connected with a high-temperature air inlet of a gasification furnace and a second inlet of combustion air of a combustor, and an outlet of the mixer is connected with a first inlet of the combustion air of the combustor; the chimney is connected with the flue gas inlet of the gasification furnace and the second inlet of the mixer through a pipeline and a fan.

And the pipeline of the flue gas side inlet and the pipeline of the flue gas side outlet of the heat accumulating type heat exchanger are both provided with control valves.

And control valves are arranged on an air side inlet pipeline and an air side outlet pipeline of the heat accumulating type heat exchanger.

The heat accumulating type heat exchanger comprises a shell and a heat accumulating medium arranged in the shell, wherein the heat accumulating medium absorbs heat of high-temperature flue gas and is used for heating entering low-temperature combustion-supporting air.

The heat storage medium is arranged in the shell in three layers, and the three layers are sequentially arranged from the smoke side inlet to the smoke side outlet, namely a first layer filled with porous phase change ceramic balls, a second layer filled with heat storage ceramic balls and a third layer filled with heat storage cast iron balls.

The porous phase-change ceramic ball is composed of a porous ceramic shell and sodium sulfate encapsulated in an inner cavity of the shell, the average outer diameter of the porous phase-change ceramic ball is 30-50mm, and the inner diameter of the inner cavity is 20 mm.

The height ratio of the first layer, the second layer and the third layer in the space in the shell is 1: 2.

The combustor comprises an air inlet pipe, a combustion outer cavity and a combustion inner cavity, the air inlet pipe is provided with a first opening communicated with the combustion outer cavity, and the air inlet pipe is provided with a second opening communicated with the combustion inner cavity in a tangential direction; the combustion outer cavity is arranged in a jacket space outside the combustion inner cavity, and the tail end of the combustion outer cavity is communicated with the tail end of the combustion inner cavity.

A premixing cavity is arranged between the combustion outer cavity and the first opening, an air equalizing plate is arranged between the premixing cavity and the combustion outer cavity, and the premixing cavity is communicated with the first opening. The air equalizing plate is arranged to uniformly distribute the biomass gas in the combustion outer cavity, so that the combustion is more uniform, and the combustion efficiency is improved.

The air-equalizing plate may be a perforated plate.

Compared with the prior art, the beneficial effects of the utility model are that: the energy can be effectively saved, the conversion rate of the biomass gas can be improved, and the conversion rate can reach 70-78%; the combustion is sufficient, the emission of NOx can be effectively reduced, the emission of NOx is enabled to be below the national standard, and the emission of NOx can be controlled to be 80-150 mg.

Drawings

FIG. 1 is a schematic diagram of the system architecture of the biomass low-nitrogen gasification device of the present invention;

FIG. 2 is a schematic axial sectional view of a burner in the biomass low-nitrogen apparatus of the present invention;

FIG. 3 is a schematic left view of a burner of the biomass low-nitrogen apparatus of the present invention;

fig. 4 is a cross-sectional view of a regenerative heat exchanger in the biomass low-nitrogen device of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

A biomass low-nitrogen gasification device is shown in figure 1 and comprises a gasification furnace 1, a combustor 2 and a boiler 3, wherein an air outlet of the gasification furnace 1 is connected with a fuel inlet of the combustor 2 through a pipeline, the combustor 2 is installed on the boiler 3, the boiler 3 is provided with two exhaust ports which are respectively connected with flue gas side inlets of heat accumulating type heat exchangers (41, 42), flue gas side outlets of the heat accumulating type heat exchangers (41, 42) are connected with a chimney 5 through pipelines, and flue gas after heat exchange is discharged through the chimney 5. The branch pipelines arranged on the preheating air pipe are respectively connected with the air side connectors of the two heat accumulating type heat exchangers (41, 42) and then respectively connected with the auxiliary mixing chamber 7, and the air heated by the heat accumulating type heat exchangers (41, 42) is collected in the auxiliary mixing chamber 7, so that the preheating air temperature of the two heat accumulating type heat exchangers (41, 42) is balanced, the hot air quantity of the mixer 8 is ensured all the time, and the air can be uninterruptedly supplied to the mixer 8. The auxiliary mixing chamber 7 may be a cavity for storing and buffering preheated air. The auxiliary mixing chamber 7 is provided with a first outlet connected with a first inlet of the mixer 8, and the chimney 5 is provided with a pipeline connected with a second inlet of the mixer 8 through the fan 6 and used for introducing part of flue gas and high-temperature combustion air to mix in the mixer 8. The mixer 8 is preferably a gas mixer. The outlet of said mixer 8 is connected to a first inlet 28 of combustion air of the burner 2. The auxiliary mixing chamber 7 is provided with a second outlet connected with the high-temperature air inlet of the gasification furnace 1 and the combustion air second inlet 29 of the combustor 2, and the high-temperature air is utilized for gasification, so that the gasification temperature can be increased, the combustion temperature of the biomass gas is increased, and the gasification efficiency is effectively improved. The chimney 5 is connected with the flue gas inlet of the gasification furnace 1 through a pipeline and a fan 6, and biomass in the gasification furnace 1 is preheated by using flue gas waste heat, so that the emission of nitrogen oxides is effectively reduced.

Wherein, the flue gas side inlet pipeline and the flue gas side outlet pipeline of the heat accumulating type heat exchanger (41, 42) are both provided with a control valve 9. The air side inlet pipelines and the air side outlet pipelines of the heat accumulating type heat exchangers (41, 42) are both provided with control valves 9, and the flow direction of flue gas or combustion air can be regulated and controlled through the control valves. The control valve 9 is preferably a solenoid valve.

The regenerative heat exchanger (41, 42) is shown in fig. 4 and comprises a housing with a flue gas side inlet 48, a flue gas side outlet 49, an air side inlet 47 and an air side outlet 46, and a regenerative medium disposed within the housing. The heat storage medium absorbs the heat of the high-temperature flue gas and is then used for heating the entering low-temperature combustion air. Wherein, the heat accumulation medium is arranged in layers in the shell so as to improve the heat exchange efficiency. The heat storage medium is arranged in the shell in three layers, and the three layers are sequentially arranged from the smoke side inlet 48 to the smoke side outlet 49, namely a first layer filled with porous phase change ceramic balls, a second layer filled with heat storage ceramic balls and a third layer filled with heat storage cast iron balls. The first layer of porous phase-change ceramic balls has a fireproof function, high heat capacity and quick heat transfer, can store the waste heat of the flue gas in a phase-change medium in the ceramic balls serving as a heat accumulator, absorbs the waste heat of the high-temperature flue gas through melting of the phase-change medium, and releases heat to heat low-temperature combustion-supporting air through solidification of the phase-change medium; the flue gas after the first heat exchange sequentially passes through the heat storage ceramic balls with relatively small heat storage capacity for heat exchange and then passes through the cast iron balls with smaller heat storage capacity for heat exchange, so that the waste heat of the flue gas can be effectively absorbed, and the heat exchange efficiency is improved. The porous phase-change ceramic ball is composed of a porous ceramic shell and sodium sulfate packaged in the inner cavity of the shell, phase-change heat storage is generated in the inner cavity of the shell after the sodium sulfate absorbs heat, and the heat storage capacity is very high. The average outer diameter of the porous phase-change ceramic ball is 30-50mm, wherein the inner diameter of the inner cavity is about 20 mm. The height ratio of the first layer to the second layer to the third layer in the space in the shell is 1: 2, so that heat exchange with flue gas can be performed to the maximum extent, waste heat of the flue gas can be absorbed, and heat exchange with air can be performed to the maximum extent to heat the air.

2-3, the burner comprises an air inlet pipe 21, a combustion outer cavity 25 and a combustion inner cavity 26, the air inlet pipe 21 is provided with a first opening 22 connected with the combustion outer cavity 25, and part of biomass gas is input into the combustion outer cavity 25 for combustion; the air inlet pipe 21 is provided with a second opening 27 which is tangentially communicated with the combustion inner cavity 26, and the rest biomass gas is input into the combustion inner cavity 26 for rotary combustion; the inner layer and the outer layer can be formed for staged combustion, double flame superposition is formed, combustion is more sufficient, combustion efficiency can be effectively improved, and emission of NOx is reduced. The combustion outer cavity 25 is arranged in a jacket space formed by the combustion inner cavity 26 and the shell, and the tail end of the combustion outer cavity 25 is communicated with the tail end of the combustion inner cavity 26, so that the flames of the combustion of the inner layer and the outer layer are overlapped at an outlet, and the combustion efficiency is further improved. A premixing cavity 23 is arranged between the combustion outer cavity 25 and the first opening 22, an air equalizing plate 24 is arranged between the premixing cavity 23 and the combustion outer cavity 25, the premixing cavity 23 is communicated with the first opening 22, and biomass gas is uniformly distributed in the combustion outer cavity 25 through the arranged air equalizing plate 24, so that the combustion is more uniform, and the combustion efficiency is improved. The guide block 30 is arranged at the first opening 22 and used for uniformly overflowing fuel in the air-equalizing plate 24 under the guidance of the guide block so as to achieve the purpose of uniform distribution of the fuel. Wherein, the air-equalizing plate 24 can be a perforated plate. The outer combustion chamber 25 is provided with a first inlet 28 for combustion air, and the first inlet 28 for combustion air and the outer combustion chamber 25 can be tangentially connected. The first inlet 28 of the combustion air refers to the mixture of high-temperature air and flue gas, so that the combustion efficiency can be effectively improved. The combustion inner cavity 26 is provided with a second inlet 29 of combustion air, and the second inlet 29 of combustion air is connected with the combustion inner cavity 26. The high-temperature air is introduced into the combustion air second inlet 29, so that the combustion temperature can be effectively increased to ensure that the fuel is stably ignited, and the combustion air is overlapped with the flame of the combustion outer cavity 25 to effectively reduce the emission of nitrogen oxides.

The utility model discloses two discharge ports of boiler respectively with the air intake connection of heat accumulation formula heat exchanger (41, 42), two chimney 5 is connected to the air exit of heat accumulation formula heat exchanger (41, 42), the exhaust emission after will handling. When the boiler works, when exhaust gas discharged by the boiler enters the chimney 5 from the first heat accumulating type heat exchanger 41, combustion-supporting air enters the auxiliary mixing chamber 7 after passing through the second heat accumulating type heat exchanger 42; when the exhaust gas discharged by the boiler enters the chimney 5 from the second heat accumulating type heat exchanger 42, the combustion air enters the auxiliary mixing chamber 7 after passing through the first heat accumulating type heat exchanger 41, and the two heat exchanging and accumulating type heat exchangers (41, 42) perform switching type heat exchange so as to improve the heat exchange efficiency. The smoke discharged by the boiler passes through the heat storage medium and is output to the chimney 5 through the air outlet, and the high-temperature smoke heats the heat storage medium to 700-800 ℃ when passing through the heat storage medium in the heat storage type heat exchanger (41, 42). After the set time, the control valve 9 is used for controlling switching, the air inlet control valve 9 of the current regenerative heat exchanger (41, 42) is closed, the combustion air pipe control valve 9 is opened, the air inlet control valve 9 of the other regenerative heat exchanger (41, 42) is opened, and the control valve 9 is closed; the exhaust gas is absorbed by the heat storage medium in the heat storage type heat exchanger (41, 42), the temperature of the exhaust gas is reduced to 100-150 ℃, and then the exhaust gas is exhausted to the chimney 5, and simultaneously the heat storage medium in the heat storage type heat exchanger (41, 42) is heated. The combustion air is heated by the heat storage medium in the heat storage type heat exchanger (41, 42), and then the temperature of the combustion air is raised to 650-750 ℃ and then the combustion air enters the auxiliary mixing chamber 7. Flue gas waste heat after having utilized the burning in flue gas emission switches over preheats combustion-supporting air, can effective energy saving, improves the treatment effect.

The gasification furnace measures the gasification efficiency to reach more than 70 percent according to NY/T2907-2016 technical conditions of biomass atmospheric fixed bed gasification furnace, NY/T1417-2007 quality evaluation technical specification of straw gasification furnace and GB/T10180-2017 Standard test method of Industrial boiler thermal performance experiment regulations, the gas heat value is 4.48MJ/Nm3, and the gas yield is 2.5m3/kg.

The utility model discloses biomass low nitrogen gasification device's fume emission refers to HJ57-2017 "fixed pollution source waste gas-sulfur dioxide's survey-fixed potential electrolysis method", GB/13271- "2047" boiler atmospheric pollutants discharge standard ", GB/T16157-1996" particulate matter in the fixed pollution source exhaust and gaseous pollutant sampling method ", GB/T10180-2017" industrial boiler thermal engineering performance experimental procedures ", GB/5468-" boiler smoke and dust test method "standard detection obtains the data, the nitrogen oxide control is between 80-150mg/m3, general detection average is at 130mg/m3, the oxygen content is 5.1-5.4%.

The above description is only a preferred embodiment of the present invention, and the scope of the present invention should not be limited thereby, and all the simple equivalent changes and modifications made in the claims and the description of the new invention are also within the scope of the present invention.

Claims

1. A biomass low-nitrogen gasification device is characterized by comprising a gasification furnace, a combustor and a boiler, wherein an air outlet of the gasification furnace is connected with a fuel inlet of the combustor through a pipeline, the combustor is arranged on the boiler, and the boiler is provided with two smoke outlets which are connected with a chimney through a pipeline; heat accumulating type heat exchangers are respectively arranged between the smoke exhaust port and the chimney, a preheating air pipe is respectively connected with the two heat accumulating type heat exchangers and then is respectively connected with an auxiliary mixing chamber, the auxiliary mixing chamber is provided with a first outlet which is connected with an inlet of a mixer, the auxiliary mixing chamber is provided with a second outlet which is connected with a high-temperature air inlet of a gasification furnace and a second inlet of combustion air of a combustor, and an outlet of the mixer is connected with a first inlet of the combustion air of the combustor; the chimney is connected with the flue gas inlet of the gasification furnace through a pipeline and a fan.

2. The biomass low-nitrogen gasification device according to claim 1, wherein the flue gas inlet pipeline and the flue gas outlet pipeline of the regenerative heat exchanger are provided with control valves.

3. The biomass low-nitrogen gasification device according to claim 2, wherein the preheated air outlet pipeline and the preheated air outlet pipeline of the regenerative heat exchanger are provided with control valves.

4. The biomass low-nitrogen gasification device according to claim 3, wherein the regenerative heat exchanger comprises a housing and a regenerative medium disposed in the housing.

5. The biomass low-nitrogen gasification device according to claim 4, wherein the heat storage medium is arranged in the shell in three layers, and three layers are arranged in sequence from the flue gas side inlet to the flue gas side outlet, namely a first layer filled with porous phase-change ceramic balls, a second layer filled with heat storage ceramic balls and a third layer filled with heat storage cast iron balls.

6. The biomass low-nitrogen gasification device according to claim 5, wherein the porous phase-change ceramic balls are composed of a porous ceramic shell and sodium sulfate encapsulated in the inner cavity of the shell, the average outer diameter of the porous phase-change ceramic balls is 30-50mm, and the inner diameter of the inner cavity is 20 mm.

7. The biomass low-nitrogen gasification device according to claim 6, wherein the height ratio of the first layer, the second layer and the third layer in the space in the shell is 1: 2.

8. The biomass low-nitrogen gasification device according to claim 3, wherein the burner comprises an air inlet pipe, a combustion outer cavity and a combustion inner cavity, the air inlet pipe is provided with a first opening communicated with the combustion outer cavity, and the air inlet pipe is provided with a second opening communicated with the combustion inner cavity tangentially; the combustion outer cavity is arranged in a jacket space outside the combustion inner cavity, and the tail end of the combustion outer cavity is communicated with the tail end of the combustion inner cavity.

9. The biomass low-nitrogen gasification device according to claim 8, wherein a premixing cavity is arranged between the outer combustion cavity and the first opening, an air equalizing plate is arranged between the premixing cavity and the outer combustion cavity, the premixing cavity is communicated with the first opening, and the air equalizing plate is arranged to uniformly distribute the biomass gas in the outer combustion cavity.

10. The biomass low-nitrogen gasification device according to claim 9, wherein the air-equalizing plate is a perforated plate.