CN210532368U

CN210532368U - Flameless combustion machine

Info

Publication number: CN210532368U
Application number: CN201921311916.3U
Authority: CN
Inventors: 李为臻
Original assignee: Red Heat Combustion Technology Dalian Co ltd
Current assignee: Red Heat Combustion Technology Dalian Co ltd
Priority date: 2019-08-14
Filing date: 2019-08-14
Publication date: 2020-05-15
Anticipated expiration: 2029-08-14

Abstract

The flameless combustor comprises a controller, an air mixer and a flameless combustor, wherein an air outlet of the air mixer is hermetically connected with a combustion cavity inlet of the flameless combustor, the flameless combustor is a hollow integral catalyst or a hollow shell, the catalyst is installed on the hollow integral catalyst, one end of the shell or one end of the integral catalyst is provided with a gas inlet of gas and combustion-supporting gas mixed gas, the gas inlet is connected with the combustion cavity inlet, and the catalyst is of a porous structure. The utility model discloses a flameless combustor combines together air mixer and catalysis flameless combustor and constitutes holistic combustor structure, and the catalysis flameless combustor adopts individual layer penetrating structure, and whole flameless combustor simple structure can be applied to in equipment such as water heater, boiler, easily installs, and the heat production gauge height.

Description

Flameless combustion machine

Technical Field

The utility model relates to a fuel combustor technical field especially relates to catalytic combustion technical field.

Background

Combustion can be divided into two categories depending on the presence or absence of visible flame: flame combustion and flameless combustion. Flame combustion has two fatal disadvantages: (1) flame combustion is an oxidation reaction of combustion substances under the participation of free radicals, and relates to gas-phase initiation of the free radicals (particularly oxygen free radicals), a part of electron excited state products are inevitably generated, energy is released in the form of visible light, the part of energy cannot be utilized and is lost, toxic and harmful gases such as formaldehyde, carbon monoxide (CO) and the like are generated due to incomplete combustion, and the fuel utilization rate is low. (2) The gas phase initiation of the free radicals enables nitrogen in the air to participate in combustion reaction to form toxic pollutants NOx, considerable incompletely combusted HC and CO are generated at low combustion efficiency, and the emission of the toxic pollutants NOx into the atmosphere can cause environmental pollution.

Most of the traditional burners adopt a flame combustion mode, and the mode has the problems of incomplete combustion of gas fuel, low heat efficiency, low fuel utilization rate, high CO emission concentration and the like.

The low-nitrogen flame combustion technology is used for reducing the generation of thermal NOx to a certain extent by reducing the flame temperature, or reducing the generated NOx into N2 by forming a high-temperature reducing atmosphere, and finally achieving the aim of low NOx emission. The existing low-nitrogen flame combustion technology mainly comprises an air staged combustion technology, a fuel staged combustion technology, a flue gas recirculation technology, a lean-burn premixed combustion technology, a full-premixed surface combustion technology and the like. The air staged combustion firstly utilizes the oxygen-poor combustion of the rich combustion area to reduce the combustion speed and temperature, and then utilizes the oxygen-rich combustion of the burnout area to burn out the fuel and simultaneously avoid the overhigh flame temperature, thereby reducing the generation of thermal NOx; the fuel staged combustion is to reduce NOx generated in the main combustion area into N2 by utilizing the reducing hydrocarbon groups formed by the combustion of the secondary fuel at high temperature so as to realize the emission reduction of NOx; the flue gas recirculation is to return part of the flue gas to the gas supply system to absorb heat and reduce the oxygen concentration of the mixed gas, so that the combustion speed and temperature are reduced, the generation of NOx is inhibited, and the acidic flue gas condensate water easily corrodes the impeller of the fan and the internal elements of the combustor while the heat loss of the flue gas is increased by the circulating flue gas; lean-burn premixed combustion means that a small amount of gas and a large amount of air are completely mixed on a molecular level and then uniformly combusted to reduce the flame temperature and reduce the generation of NOx, and meanwhile, the uniform and sufficient combustion under the oxygen-rich condition enables the emission of HC and CO to be obviously reduced, but the excessive air not only increases the heat loss of smoke exhaust, but also increases the load of a fan, and has low heat efficiency and large energy consumption; the full-premixing surface combustion is carried out on the surface of a mesh material such as a porous flow equalizing plate on the basis of completely mixing gas and air molecules, the combustion speed is high, the flame length is short, the temperature is low, the generation of thermal NOx can be greatly reduced, but the metal fiber braided fabric and the like are easy to block, so that the performance of a combustor is greatly reduced. Gas boilers of different power currently usually adopt one or more of the above combustion technologies to achieve the purpose of reducing NOx emission, and the defects of the above technologies make the current burners generally expensive and complicated to operate.

Compared with flame combustion, flameless combustion can enable combustion to be performed more uniformly and stably, and local high temperature is avoided, so that the generation amount of nitrogen oxides is extremely low. Flameless combustion includes high temperature air flameless combustion and catalytic flameless combustion. High temperature air combustion utilizes high temperature air to heat fuel gas to exceed the autoignition temperature, so that flameless combustion occurs in a relatively wide area, local high temperature is avoided, and NOx emission is effectively reduced.

One of the effective ways to solve the inefficiency of flame combustion and high emission is catalytic combustion, which has the advantages of high combustion efficiency (low emission of CO and incompletely combusted HC), low combustion temperature (<1200 ℃, thus low emission of NOx), stable and controllable combustion process (by controlling catalytic reaction), and the like. Catalytic combustion is an oxidation reaction of low-carbon hydrocarbons on the surface of a catalyst, and is a combustion method mainly based on flameless combustion. The key to the application of catalytic combustion technology is the design, research and development of efficient catalytic combustors.

At present, the burners applied to equipment such as water heaters and boilers are roughly divided into two types: (1) a metal fiber burner, such as chinese patent No. CN201821021248.6 entitled fully premixed cast aluminum condensing boiler, realizes infrared combustion by the metal fiber burner; chinese patent No. cn201610518699.x entitled fully premixed metal fiber burner and boiler using the same realizes infrared combustion by the metal fiber burner. (2) Catalytic burners, such as chinese patent No. cn201711223180.x, entitled catalytic reaction device and gas water heater, reduce the content of carbon monoxide in combustion flue gas by disposing a catalytic reaction device (the catalytic reaction device is a catalyst disposed on a ceramic substrate) in a housing. (2) Catalytic burners, such as chinese patent No. 201711005587.5, entitled gas water heater, and No. 201711018017.X, entitled gas water heater, have a preheating burner and a catalytic burner disposed within a water heater housing. The catalyst is arranged in the heat collecting cover or the shell of the water heater, and has the advantages of complex structure, poor flexibility and low heat production quantity.

SUMMERY OF THE UTILITY MODEL

In order to solve the above problems existing in the application process of the existing catalytic burner, the utility model provides an independent flameless burner.

The utility model discloses a realize that the technical scheme that above-mentioned purpose adopted is: the flameless combustor comprises a controller, an air mixer and a flameless combustor, wherein an air outlet of the air mixer is hermetically connected with a combustion cavity inlet of the flameless combustor, the flameless combustor is a hollow integral catalyst or a hollow shell, the catalyst is installed on the hollow integral catalyst, one end of the shell or one end of the integral catalyst is provided with a gas inlet of gas and combustion-supporting gas mixed gas, the gas inlet is connected with the combustion cavity inlet, and the catalyst is of a porous structure.

The air mixer comprises an air blower, a gas control valve, a gas nozzle and an air distributor, an air outlet channel of the air blower is connected with a gas pipeline provided with the control valve, and the gas nozzle, an igniter and the air distributor are arranged in a channel formed by an air outlet of the air blower and a combustion cavity inlet 8 of the flameless combustor.

The air mixer comprises a full-premixing fan, a fuel gas control valve and an air distributor, wherein the outlet of a fuel gas pipeline provided with the control valve is connected with the air inlet of the full-premixing fan, and an igniter and the air distributor are arranged in a channel formed by the air outlet of the full-premixing fan and the inlet of a combustion cavity of the flameless combustor.

The flameless burner of the integral catalyst is of a cylindrical or barrel-shaped structure; the shell of the flameless combustor is of a cylindrical or cylindrical structure, and the catalyst is hermetically arranged in an installation hole on the shell; the shell is of a conical structure, the top of the conical structure is connected with an inlet of the combustion chamber, and the bottom of the conical structure is provided with a catalyst.

The shell is made of high-temperature-resistant metal or ceramic material.

The utility model discloses a flameless combustor combines together air mixer and catalysis flameless combustor and constitutes holistic combustor structure, and catalysis flameless combustor adopts the individual layer penetrating structure, and whole flameless combustor simple structure can be applied to equipment such as water heater, boiler, easily installs, and the heat production is high; by the control method, the flame combustion is quickly converted into the catalytic flameless combustion after ignition, so that the over-high local combustion temperature is avoided, the generation of NOx is reduced, the catalytic flameless combustion efficiency is high, the generation amount of incomplete combustion products CO and HC is small, and the combustion tail gas can meet the direct emission requirement.

Drawings

Fig. 1 is a main view structure diagram of a flameless combustion engine using a blower according to an embodiment of the present invention.

Fig. 2 is a main view structure diagram of a flameless combustor employing a fully premixed fan according to an embodiment of the present invention.

In the figure: 1. the device comprises a blower, 2, a controller, 3, an igniter, 4, a gas nozzle, 5, an air distributor, 6, a shell, 7, a catalyst, 8, a combustion cavity inlet, 9, a proportional valve, 10, an air mixer outlet, 11 and a full-premixing fan.

Detailed Description

In the first embodiment, a flameless combustion machine using an air blower is structurally shown in fig. 1, and includes a controller 2, an air mixer and a flameless combustor, wherein the air blower in the air mixer is the air blower 1, an air outlet of the air blower 1 is hermetically connected with a combustion chamber inlet 8 of the flameless combustor, an air outlet channel of the air blower is connected with a gas pipeline provided with a control valve 9, a gas nozzle 4, an igniter 3 and an air distributor 5 are arranged in a channel formed between the air outlet of the air blower 1 and the combustion chamber inlet 8 of the flameless combustor, and the gas nozzle 4 is located at an outlet of the gas pipeline. The flameless combustor is a hollow shell 6, a catalytic converter 7 is installed on the shell, one end of the shell 6 or one end of the integral catalytic converter 7 is provided with a gas inlet of fuel gas and combustion-supporting gas, the gas inlet is connected with a combustion chamber inlet 8, and the catalytic converter 7 is of a porous catalyst structure. The shell 6 of the flameless combustor is of a cylindrical or barrel-shaped structure, and the catalyst 7 is hermetically arranged in an installation hole on the shell 6 or the catalyst 7 is arranged on the inner side of the shell 6; the shell 6 is made of high-temperature-resistant metal or ceramic material.

In the second embodiment, the flameless combustor using the fully premixed fan is structurally shown in fig. 2, and includes a controller 2, an air mixer and a flameless combustor, the fan in the air mixer is a fully premixed fan 11, an outlet of a gas pipeline provided with a control valve 9 is connected with an air inlet of the fully premixed fan 11, an air outlet of the fully premixed fan 11 is hermetically connected with an inlet 8 of a combustion chamber of the flameless combustor, and an igniter 3 and an air distributor 5 are installed in a channel formed between the air outlet of the fully premixed fan 11 and the inlet 8 of the combustion chamber of the flameless combustor. The flameless combustor is a hollow shell 6, a catalyst 7 is arranged on the shell, one end of the shell 6 or one end of the integral catalyst 7 is provided with a gas inlet of mixed gas of fuel gas and combustion-supporting gas, the gas inlet is connected with a combustion cavity inlet 8, and the catalyst 7 is of a porous catalyst structure. The shell 6 of the flameless combustor is of a cylindrical or barrel-shaped structure, and the catalyst 7 is hermetically arranged in an installation hole on the shell 6 or the catalyst 7 is arranged on the inner side of the shell 6;

the housing 6 may also be of a conical configuration, the top of which is connected to the combustion chamber inlet 8 and the bottom of which is fitted with a catalyst 7.

The principle is as follows: combustion-supporting gas and gas mix through the air mixer, through the air distributor misce bene, the gas mixture gets into in the cavity of catalytic combustor through combustion chamber entry 8, ignite through some firearm (ignition electrode), the gas combustion heats the catalyst converter, control gas flame when the temperature of catalyst converter reaches catalysis light-off temperature above and extinguish, the gas mixture of combustion-supporting gas and gas pierces through the hole of catalyst and carries out catalysis flameless burning on the catalyst surface, the release heat, the dotted line is gas and combustion-supporting gas mixed gas flow direction in the figure. The air inlet volume of the fan and the on-off of the gas pipeline valve are controlled by the controller 2, the air input of the gas is controlled by the proportional valve 9, and the proportion of the combustion-supporting gas and the gas is adjusted by matching with the air input of the fan.

The control method of the flameless combustor comprises the following three steps:

a) the method comprises the following steps of (1) controlling the proportion of combustion-supporting gas and fuel gas, wherein the combustion-supporting gas is air, and the method for controlling the proportion of the combustion-supporting gas and the fuel gas comprises the following steps: 1) the ratio of air to fuel gas is 1.01-2.5; 2) according to the tempering linear velocity and the fire line removing velocity of the fuel used, which are known by a person skilled in the art, the linear velocity of the premixed gas is adjusted between the tempering linear velocity and the fire line removing velocity;

b) ignition and flameout control are carried out in the combustion process, after the igniter 3 is started to ignite, a flameless combustion cavity and a catalyst 7 in the heating shell 6 are heated, the catalyst 7 is heated to red heat or more than 600 ℃, flameout is carried out, and the flameout method is as follows: 1) increasing the linear speed of the premixed gas to be higher than the speed of taking off the fire line so as to extinguish the flame; 2) reducing the gas concentration to 0-4%;

c) the combustion ratio of the combustion-supporting gas and the fuel gas is adjusted back, and the method for adjusting the combustion ratio of the combustion-supporting gas and the fuel gas is as follows: 1) adjusting the linear velocity of the premixed gas to be greater than the tempering linear velocity; 2) the ratio of the air and the fuel gas is adjusted to be 1.01-2.5.

While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application belong to the protection scope of the present invention.

Claims

1. Flameless combustion machine, its characterized in that: including controller (2), air mixer and flameless combustor, air outlet (10) of air mixer and flameless combustor's burning chamber entry (8) sealing connection, flameless combustor is hollow holistic catalyst converter (7) or installs catalyst converter (7) for on hollow casing (6), casing (6) one end or holistic catalyst converter (7) one end are equipped with the gas inlet of gas and combustion-supporting gas mixture, gas inlet connection burning chamber entry (8), catalyst converter (7) are porous structure.

2. The flameless combustion machine of claim 1, wherein: the air mixer comprises an air blower (1), a gas control valve (9), a gas nozzle (4) and an air distributor (5), an air outlet channel of the air blower is connected with a gas pipeline provided with the control valve (9), and the gas nozzle (4), an igniter (3) and the air distributor (5) are arranged in a channel formed by an air outlet of the air blower and a combustion cavity inlet (8) of the flameless combustor.

3. The flameless combustion machine of claim 1, wherein: the air mixer comprises a full-premixing fan (11), a fuel control valve (9) and an air distributor (5), a fuel pipeline outlet provided with the control valve (9) is connected with an air inlet of the full-premixing fan (11), and an igniter (3) and the air distributor (5) are arranged in a channel formed by an air outlet of the full-premixing fan (11) and a combustion cavity inlet (8) of the flameless combustor.

4. The flameless combustion machine of claim 1, wherein: the flameless burner of the integral catalyst (7) is of a cylindrical or barrel-shaped structure; the shell (6) of the flameless combustor is of a cylindrical or cylindrical structure, and the catalyst (7) is hermetically arranged in an installation hole in the shell (6); the shell (6) is of a conical structure, the top of the conical structure is connected with a combustion chamber inlet (8), and the bottom of the conical structure is provided with a catalyst (7).

5. The flameless combustion machine of claim 1, wherein: the shell (6) is made of high-temperature-resistant metal or ceramic material.