CN1322598C

CN1322598C - Counterflow heat exchanging burners

Info

Publication number: CN1322598C
Application number: CNB2005100111081A
Authority: CN
Inventors: 钟北京; 王国锋; 伍亨
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2005-01-07
Filing date: 2005-01-07
Publication date: 2007-06-20
Anticipated expiration: 2025-01-07
Also published as: CN1644985A

Abstract

The present invention relates to a backflow heat exchange type burner which is composed of a heat insulation wall body (3) of an outer casing, and two insulation wall bodies (5a, 5b) used for isolating flammable premixed gas and smoke gas, wherein the heat conducting coefficient of one insulation wall body is large, the heat conducting coefficient of the other insulation wall body is small, and a combustion zone (8) is formed at the center of the burner. The insulation wall body with a large heat conducting coefficient is used for recovering the heat quantity of the smoke gas, and the insulation wall body with a small heat conducting coefficient is used for generating large temperature difference required by the electricity generation of thermoelectric elements. The burner can be ignited by an igniter, and the flammable premixed gas can be automatically ignited or ignited in a mixing mode under the action of combustion supporting catalysts. By burning fuel, chemical energy is effectively converted into heat energy, and thus, an integral power generation device is formed from the burner and the thermoelectric elements arranged in the insulation wall body with a small heat conducting coefficient. The present invention satisfies different requirements, and has a wide application range. For example, the burner can be used as a power source of a large device, or a distributed power generation device; the burner can be used as a power supply of a mobile device and a portable device after miniaturization (micromation).

Description

A kind of counterflow heat exchanging burners

Technical field

The invention belongs to the high-efficiency cleaning utilization of fuel, particularly utilize fuel combustion to realize thermoelectric directly conversion technology field.

Background technology

So-called thermoelectric conversion device is exactly that the thermoelectric element that is made of thermoelectric material is placed hot-cool environment or air-flow, and thermoelectric element can output potential under the action of thermal difference of hot-cool environment or air-flow.The generating efficiency of thermoelectric conversion device depends on the temperature difference at the hot and cold two ends of thermoelectric element to a great extent.

Thermoelectric conversion device based on burning can directly be realized the transformation of heat energy to electric energy, and do not need hot machine, and combustion efficiency height, ignition temperature is lower, avoid the ordinary hot machine power generating system because the ignition temperature of fuel is very high, and factor such as incomplete combustion, causing has a large amount of dusty gas dischargings in the flue gas, influence the adverse consequences of air quality.

In we are original " directly realizing the device of thermoelectric conversion based on fuel combustion " patent (patent of invention number: 02291536.2; Application for a patent for invention number: 021568960), adopted a kind of swirl type burner of special construction.This burner is realized heat transferred between high-temperature flue gas and the flammable premixed gas body flammable premixed gas being heated before burning by the body of wall that separates in lagging casing, flammable premixed gas and flue gas.So not only can improve the stability of flame, can also reclaim the heat of high-temperature flue gas.But, in the Blast Furnace Top Gas Recovery Turbine Unit (TRT) of this patent, thermoelectric element also is to be arranged in the body of wall of realizing flue gas and flammable premixed gas exchange heat, thereby produced following problem: in order to improve the rate of recovery of heat, above-mentioned body of wall in the burner need use the big material of conductive coefficient, but be to use the big material of conductive coefficient just to be difficult to obtain the required big temperature difference of thermoelectric element generating, seriously influenced generating efficiency.Therefore, in the described Blast Furnace Top Gas Recovery Turbine Unit (TRT) of this patent, be difficult to take into account simultaneously heat? recovery and thermoelectric efficiently conversion efficiently.How improving the utilance of fuel and the generating efficiency of thermoelectric conversion device is the key technology of development based on the fuel combustion thermoelectric conversion device.

Summary of the invention

Purpose of the present invention is exactly in order to solve the difficult satisfactory to both parties contradiction of heat? recovery above-mentioned and thermoelectric element generating efficiency.The invention provides a kind of counterflow heat exchanging burners, it can with the supporting use of thermoelectric element, constitute an integral type thermoelectric conversion device.Counterflow heat exchanging burners can be realized the conversion of energy of chemical energy thermotropism effectively, and provides the thermoelectric element generating the required big temperature difference, improves the utilance of fuel and the generating efficiency of thermoelectric conversion device simultaneously.

A kind of counterflow heat exchanging burners, burner design becomes as Fig. 1 or swirl type shown in Figure 2.The isolation body of wall (5a) that it is separated flammable premixed gas and flue gas by the adiabatic body of wall (3) of shell and two and (5b) form.Isolate body of wall (5a, 5b) burner is separated into flammable premixed gas passage (4) and exhaust gases passes (6), and constitute combustion zone (8) at the center of burner.This burner is realized the conversion of energy of chemical energy thermotropism by fuel combustion (comprising the minute yardstick burning).Flammable premixed gas and flue gas are being isolated body of wall (5a, 5b) both sides formation adverse current form.

Effective recovery and the required temperature difference problem of raising thermoelectric element generating efficiency in order to solve heat simultaneously the invention provides following technical scheme, promptly isolate the different material of bodies of wall (5a, 5b) employing conductive coefficient for two.Like this, in the bigger isolation body of wall both sides of conductive coefficient, the higher flue gas (9) of temperature can be passed to the lower flammable premixed gas of temperature (1) to heat, realizes effective recovery of heat.Simultaneously, because the temperature of flammable premixed gas raises, help the stable of combustion zone (8) flame.This conductive coefficient of isolating body of wall is big more, and the efficient of heat? recovery is high more, and the flame of combustion zone (8) is stable more.The isolation body of wall both sides less at conductive coefficient can form the bigger temperature difference, and thermoelectric element is arranged in the little isolation body of wall of conductive coefficient, and under this big action of thermal difference, thermoelectric element is realized thermoelectric efficiently conversion, outwards exports electric energy; This conductive coefficient of isolating body of wall is more little, and the temperature difference of body of wall both sides is big more, and generating efficiency is high more.Promptly, achieve different functions by selecting the isolation body of wall (5a, 5b) of two different materials.The isolation body of wall that conductive coefficient is bigger is finished the task of reclaiming flue gas heat, and the less isolation body of wall of conductive coefficient is finished the required big temperature difference task of thermoelectric element generating that forms, and improves conversion efficiency of thermoelectric.

Isolating body of wall can be that the 5a conductive coefficient is bigger, and the 5b conductive coefficient is less, also can be that the 5a conductive coefficient is less, and the 5b conductive coefficient is bigger.

In addition, can near the isolation body of wall (5) of position combustion zone (8), be coated with catalyst, utilize the surface catalysis burning further to strengthen the stability of flame, reduce ignition temperature simultaneously, realize pollutant NO _xLow emission.

This burner and thermoelectric element have constituted an integral type Blast Furnace Top Gas Recovery Turbine Unit (TRT), satisfy different needs, range of application is very wide, as power source or the distributed power generation equipment that both can be used as main equipment, can be used as the power supply of mobile device, portable equipment after its small-sized (miniature) is changed.

Description of drawings

Fig. 1 is the internal structure schematic diagram of rectangle counterflow heat exchanging burners, and Fig. 1 (b) is the A-A cutaway view of Fig. 1 (a);

Fig. 2 is the internal structure schematic diagram of circular or oval counterflow heat exchanging burners, and Fig. 2 (b) is the B-B cutaway view of Fig. 2 (a).

Embodiment

Below in conjunction with accompanying drawing, describe the specific embodiment of the present invention in detail.

Fig. 1 is the internal structure schematic diagram of rectangle counterflow heat exchanging burners.1 is flammable premixed gas among the figure, the 2nd, and flammable premixed gas inlet, the 3rd, the adiabatic body of wall of shell, the 4th, flammable premixed gas passage, be to isolate body of wall, the 6th, exhaust gases passes, the 7th, igniter, the 8th, combustion zone 5 (comprising 5a and 5b), the 9th, flue gas, the 10th, flue gas discharge opening, the 11st, igniter lead-in wire.

Burner isolates body of wall 5a by the adiabatic body of wall 3 of shell and two and 5b constitutes.The flammable premixed gas of being made up of fuel and oxidant (normally air) 1 enters burner by inlet 2, flow to the combustion zone 8 that is positioned at the burner center through flammable premixed gas passage 4 subsequently, fire burns, realize the conversion of energy of fuel chemical energy thermotropism, and form high-temperature flue gas.High-temperature flue gas leaves combustion zone 8 and enters exhaust gases passes 6, becomes the adverse current state with flammable premixed gas.The high-temperature flue gas streamwise is constantly realized exchange heat by isolating body of wall 5 with flammable premixed gas 1, and flammable premixed gas temperature before fire burns is raise, and the flue-gas temperature streamwise reduces gradually simultaneously, discharges burner through outlet 10 subsequently.Like this, the flammable premixed gas of room temperature constantly enters burner from burner inlet 2, on the way constantly by isolating the heat that body of wall 5 absorbs from high-temperature flue gas, until arrive combustion zone 8 fire burns, the high-temperature flue gas that leaves combustion zone 8 along passage 6 by isolating body of wall 5 constantly heat transferred flammable premixed gas 1.Discharge burner through the flue gas after the exchange heat 9 by outlet 10.In the design of burner, article two, isolate body of wall and adopted the different material of conductive coefficient, isolate the major function difference that body of wall is finished for every, isolate the task that body of wall is mainly finished heat? recovery for one that conductive coefficient is bigger, and another less main task of isolating body of wall of conductive coefficient is to produce the needed bigger temperature difference of thermoelectric element generating in its both sides.Like this, taken into account higher heat recovery efficiency simultaneously and improved the needed temperature difference of thermoelectric element generating efficiency, the problem that has occurred when having solved the isolation body of wall 5 that former employing is made of homogenous material.Evidence is used burner structure proposed by the invention to reach when reclaiming heat, has been obtained the intended purposes of the required big temperature difference of thermoelectric element generating again.

During system start-up, flammable premixed gas 1 flows to the combustion zone 8 that is positioned at the burner center after entering counterflow heat exchanging burners by inlet 2, is lighted by the igniter 7 that is fixed on the burner wall then, forms stable flame.Igniter is drawn by ignition fuse 11, is connected with external power source.

In addition, can also on the burner wall around the combustion zone 8, be coated with catalyst and realize the surface low-temperature catalytic combustion.Like this, not only can further expand the Flammability limits of flammable premixed gas, improve the stability of flame, and can realize the low emission of NOx.

If use hydrogen to act as a fuel, on the inwall of combustion zone, scribble catalyst simultaneously, then burner can realize that the spontaneous combustion of not having igniter starts.Use conveniently, and have only water in the flue gas, really realize zero discharge.

Burner of the present invention can have different version as required.For example, except that rectangular configuration form shown in Figure 1, can also do circular and oval-shaped structure, as shown in Figure 2.The microminiaturization of this burner can be used as the core component of the microminiature thermoelectric device of substituted chemistry battery, help promoting the microminaturization of thermoelectric device by minute yardstick combustion technology and integrated process technology, thereby the reduction product price helps commercialization, and is very easy to use.

Claims

1, a kind of counterflow heat exchanging burners, form by the adiabatic body of wall (3) of shell, two isolation bodies of wall (5a, 5b), isolate body of wall (5a, 5b) burner is separated into flammable premixed gas passage (4) and exhaust gases passes (6), and in formation combustion zone (8), the center of burner, it is characterized in that, article two, an isolation body of wall conductive coefficient is big in the isolation body of wall, and an isolation body of wall conductive coefficient is little; Igniter (7) is installed, and igniter (7) links to each other with external power supply by described adiabatic body of wall (3) leading point live wire (11) in described combustion zone (8); Be arranged in the little isolation body of wall of conductive coefficient with the matching used thermoelectric element of described burner.

2, a kind of counterflow heat exchanging burners, form by the adiabatic body of wall (3) of shell, two isolation bodies of wall (5a, 5b), isolate body of wall (5a, 5b) burner is separated into flammable premixed gas passage (4) and exhaust gases passes (6), and in formation combustion zone (8), the center of burner, it is characterized in that, article two, an isolation body of wall conductive coefficient is big in the isolation body of wall, and an isolation body of wall conductive coefficient is little; On near two described combustion zone (8) isolation bodies of wall, be coated with the combustion supporting catalyst that can make the flammable premixed gas self-ignition; Be arranged in the little isolation body of wall of conductive coefficient with the matching used thermoelectric element of described burner.

3, a kind of counterflow heat exchanging burners, form by the adiabatic body of wall (3) of shell, two isolation bodies of wall (5a, 5b), isolate body of wall (5a, 5b) burner is separated into flammable premixed gas passage (4) and exhaust gases passes (6), and in formation combustion zone (8), the center of burner, it is characterized in that, article two, an isolation body of wall conductive coefficient is big in the isolation body of wall, and an isolation body of wall conductive coefficient is little; Igniter (7) is installed, and igniter (7) links to each other with external power supply by described adiabatic body of wall (3) leading point live wire (11) in described combustion zone (8); On near two described combustion zone (8) isolation bodies of wall, be coated with combustion supporting catalyst; Be arranged in the little isolation body of wall of conductive coefficient with the matching used thermoelectric element of described burner.