Patent Description:
The present invention relates to a combustion heat generator, and more particularly to a combustion heat generator with a recirculation region for effectively dissipating heat energy by forming uniform temperature distribution in a combustion chamber.

In general, a combustion heat generator is used to uniformly heat a material to high temperature in various ovens, such as a coke oven, in the steel/material industry.

In addition, a radiant heat dissipation furnace called a radiant tube is used for heating purposes in commercial facilities as well as industrial fields.

In detail, the radiant tube also performs a similar function to a plate-type combustion heat generator by twisting a shape of a circular tube in a zigzag for safety.

<CIT> discloses a rectangular parallelepiped radiant box, on which a first burner constituted by a primary fuel injection nozzle, a secondary fuel injection nozzle, a honeycomb-type heat storage body, and a pilot burner is provided. Further, a second burner constituted by a primary fuel injection nozzle, a secondary fuel injection nozzle, a honeycomb-type heat storage body, and a pilot burner is connected to a lower portion.

<CIT> discloses a burner system for reducing air pollution comprising a blower for supplying combustion air, three cylindrical pots having the same central axis and being different in semidiameter, flat disks for supporting both ends of the pots, a plurality of air nozzles, a cylindrical emulsion injector having a plurality of orifices, and a whirler for whirling combustion air.

However, in a conventional combustion heat generator, temperature is lowered downstream (outlet) of combustion gas. That is, due to this configuration, the fuel and oxidant (mainly, air) are quickly mixed in order to stably burn the fuel, a high-temperature flame is generated, and the temperature is rapidly lowered because heat is not generated after the flame is generated.

In the combustion heat generator, a temperature deviation occurs in an external structure that emits heat due to a temperature difference in the combustion space, and accordingly, the combustion heat generator is not effective due to limitations in uniform heat radiation.

As thermal stress is generated in an area in which the temperature deviation of the combustion heat generator occurs, durability is reduced.

In addition, there is a problem in that a high concentration of nitrogen oxides (NOx) is generated in a high-temperature flame zone of the combustion heat generator.

In accordance with an aspect of the present invention, the above and other objects can be accomplished by a combustion heat generator set out in the appended set of claims. The combustion heat generator includes a plate-shaped housing having a combustion space therein and two-dimensional flow is possible; an oxidant injector provided on a first position of the housing and forming a first circulation region by inputting an oxidant to an outer periphery of an inner side of the combustion space through an oxidant injection nozzle and circulating the oxidant; a gas ejector provided on a second position of the housing and discharging a portion of gas circulating in the combustion space; and a fuel feeder installed to a central position of the housing so that a front end of a fuel injection nozzle is positioned in a second circulation region formed in a center of the combustion space by circulation of an oxidant in the first circulation region to inject fuel into the second circulation region, wherein the first position and the second position are formed on the same side of the housing respectively, wherein space combustion is generated in the combustion space based on the second circulation region and the fuel injected into the second circulation region is turned while being gradually mixed with the oxidant circulating along the first circulation region.

In this case, the housing may be formed in any one shape of a circle, an ellipse, a rectangle, and a polygon.

In addition, the oxidant injector and the gas ejector may be installed to be spaced apart from each other in parallel to the housing.

In addition, the combustion heat generator may further include: a guide member provided in the combustion space and configured to guide the oxidant injected through the oxidant injector to circulate the oxidant in one direction.

In addition, the gas ejector of the combustion heat generator may be connected to an oxidant injector of an adjacent combustion heat generator to successively install the plurality of combustion heat generators in series.

Further, a heat exchanger for increasing temperature of an oxidant input through the oxidant injector and temperature of fuel input through the fuel feeder using heat of gas discharged through the gas ejector may be provided on one side of the housing.

The combustion heat generator with a recirculation region according to the present invention as configured above may form uniform temperature distribution in a combustion chamber by forming a gas recirculation region around a central part of a combustion space in a housing and injecting fuel into the gas recirculation region to generate space combustion based on the recirculation region.

Thus, heat energy may be effectively dissipating heat energy through the combustion heat generator, and problems of durability degradation of an external structure due to temperature non-uniformity of existing combustion heat generator may be overcome.

In addition, nitrogen oxides (NOx) generated during combustion at high temperature may be reduced.

Hereinafter, the configuration and operation of specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Here, when reference numerals are applied to constituents illustrated in each drawing, it should be noted that like reference numerals indicate like elements throughout the specification.

<FIG> is a perspective view showing a combustion heat generator according to the present invention. <FIG> is a front sectional view showing the internal configuration of a combustion heat generator according to the present invention.

Referring to <FIG>, a combustion heat generator <NUM> according to an exemplary embodiment of the present invention may include a housing <NUM>, an oxidant injector <NUM>, a gas ejector <NUM>, and a fuel feeder <NUM>.

The configuration according to the present invention will be described below in detail.

First, the housing <NUM> constitutes a main body of the combustion heat generator <NUM>, and may be formed in a plate shape in which a combustion space <NUM> is provided.

In detail, the housing <NUM> may be formed in any one of a circular shape, an oval shape, a rectangular shape, and a polygonal shape. In the present invention, a case in which the housing <NUM> is formed in a rectangular plate shape will be described. However, the present invention is not limited thereto, and various modifications may be applied as long as an oxidant and fuel injected into the combustion space <NUM> may be circulated smoothly.

In this way, when the housing <NUM> is formed in a plate shape, only two-dimensional flow is possible in the combustion space <NUM> inside the housing <NUM>, and three-dimensional flow in the thickness direction of the housing <NUM> is impossible.

That is, since the combustion heat generator <NUM> having a plate shape is formed to have a large area and a relatively thin thickness, two-dimensional flow is possible. Accordingly, uniform thermal efficiency of the combustion heat generator <NUM> may be realized.

Referring to <FIG>, the oxidant injector <NUM> is provided on one side of the housing <NUM> to form a first circulation region (A) by introducing an oxidant into the outer periphery of the inner side of the combustion space <NUM> and circulating the oxidant.

Specifically, the oxidant injector <NUM> may have an oxidant injection nozzle <NUM> having a predetermined length so that an oxidant fed through an oxidant feeder (not shown) is smoothly introduced into a predetermined point of the combustion space <NUM> in the housing <NUM>.

In this case, the oxidant injection nozzle <NUM> may be installed at a point where the sides of the rectangular housing <NUM> meet each other, i.e., a corner of the housing <NUM>, so as to form the first circulation region (A) by injecting an oxidant into the outer periphery of the inner side of the combustion space <NUM>.

As another embodiment, when the housing <NUM> is formed in a circular shape (not shown), the oxidant injection nozzle <NUM> may be installed to be inclined at a predetermined angle in the tangential direction of the circle. Accordingly, by injecting an oxidant into the outer periphery of the inner side of the circular combustion space <NUM>, the first circulation region (A) may be efficiently formed.

The gas ejector <NUM> may be provided on the other side of the housing <NUM> and serves to discharge a portion of gas circulating in the combustion space <NUM> to the outside.

Specifically, the oxidant injector <NUM> and the gas ejector <NUM> may be disposed on one side of the housing <NUM> to be spaced apart from each other in parallel.

As another embodiment, as shown in <FIG>, the oxidant injector <NUM> and the gas ejector <NUM> may be installed with the fuel feeder <NUM> to be described later therebetween. In this case, the oxidant injector <NUM> and the gas ejector <NUM> may be installed on both sides of the housing <NUM> and arranged in a line to face each other.

Referring to <FIG>, as described above, when the oxidant injector <NUM> and the gas ejector <NUM> are installed on both sides of the housing <NUM> and arranged in a line to face each other, a plurality of combustion heat generator <NUM> according to the present invention may be installed in series to form a lateral heat sink system.

That is, the gas ejector <NUM> installed on the other side of the firstly disposed combustion heat generator <NUM> may be connected to the oxidant injector <NUM> installed on one side of the other adjacent combustion heat generator <NUM>'.

That is, the gas ejector <NUM> of the first combustion heat generator <NUM> becomes the oxidant injector <NUM> of the combustion heat generator <NUM> connected to the first combustion heat generator <NUM>.

Accordingly, gas discharged through the gas ejector <NUM> of the first combustion heat generator <NUM> may be re-injected through the oxidant injector <NUM> of the adjacent combustion heat generator <NUM>. Thus, a long heat sink may be formed, and the efficiency of the combustion heat generator <NUM> may be improved through dispersed injection of fuel.

In this case, in the combustion space <NUM> inside the housing <NUM> constituting the combustion heat generator <NUM>, a guide member <NUM> (see <FIG>) for guiding an oxidant may be provided so that an oxidant injected through the oxidant injector <NUM> is circulated in one direction of the combustion space <NUM>.

That is, when a plurality of combustion heat generator <NUM> is installed in series, it is necessary to change the flow direction of an oxidant injected into the combustion space <NUM> through the oxidant injector <NUM> to a desired direction (e.g., clockwise in <FIG>).

Accordingly, by installing the guide member <NUM> in the vicinity of the combustion space <NUM> of the housing <NUM> in which the oxidant injector <NUM> is installed, the flow direction of an oxidant injected into the combustion space <NUM> through the oxidant injection nozzle <NUM> may be changed to a desired direction. Thus, the first circulation region (A) may be smoothly formed.

The fuel feeder <NUM> serves to inject fuel into a second circulation region (B) formed near the center of the combustion space <NUM> by circulation of an oxidant in the first circulation region (A). The fuel feeder <NUM> may be installed so that the front end of a fuel injection nozzle <NUM> is located in the second circulation region (B).

Specifically, at least one fuel injection nozzle <NUM> of the fuel feeder <NUM> may be positioned between the oxidant injector <NUM> and the gas ejector <NUM>.

Referring to <FIG>, as another embodiment, at least one pair of the fuel injection nozzles <NUM> may be symmetrically installed on the upper and lower sides or left and right sides with respect to the center of the housing <NUM> so as to increase the fuel injection efficiency of the fuel feeder <NUM>.

Referring to <FIG>, a heat exchanger <NUM> may be provided at one side of the housing <NUM>. The heat exchanger <NUM> may use the heat of gas discharged through the gas ejector <NUM> to increase the temperature of an oxidant input through the oxidant injector <NUM> and the temperature of fuel input through the fuel feeder <NUM>. Accordingly, the heat exchanger <NUM> may improve the thermal efficiency of the combustion heat generator <NUM>.

Then, an operation of the combustion heat generator <NUM> including a recirculation region according to the present invention as configured above will be described.

First, an oxidant may be injected to flow into an inner circumference of the combustion space <NUM> through the oxidant injector <NUM> provided at one side of the housing <NUM> to provide the first circulation region A. Simultaneously, a predetermined second circulation region B may be provided by the first circulation region A adjacent to the central part of the combustion space <NUM>.

In this case, some of gas circulated inside the combustion space <NUM> may be discharged through the gas ejector <NUM> provided at the other side of the housing <NUM>.

The fuel feeder <NUM> may spray fuel through the fuel injection nozzle <NUM>, a fore end of which is positioned inside the second circulation region B, and thus may generate space combustion inside the combustion space <NUM> based on the second circulation region B.

That is, fuel sprayed to the second circulation region B may be turned while being gradually mixed with the oxidant in the first circulation region A.

Accordingly, uniform temperature distribution in the combustion space <NUM> of the combustion heat generator <NUM> may be formed by uniform reaction and heat release that are the characteristic of space combustion.

As such, uniform temperature distribution formed in the combustion space <NUM> may overcome problems of efficiency degradation and durability degradation of an external structure due to temperature non-uniformity of existing combustion heat generator, and in particular may reduce nitrogen oxides (NOx) generated during combustion in high-temperature flames.

<FIG> show the computational analysis results of the combustion heat generator <NUM> according to the present invention.

First, the housing <NUM> was formed to have a size of <NUM> in width, <NUM> in length, and <NUM> in thickness so that the combustion heat generator <NUM> according to the present invention were used for computational analysis. In this case, the thickness of a metal plate constituting the housing <NUM> was <NUM>, and the fuel injection nozzle <NUM> was configured to enter <NUM> from the wall surface of the housing <NUM> to the inside.

In addition, gas residence time in the housing <NUM> was set to <NUM> seconds, and equivalence ratio was set to <NUM> to allow <NUM> % excess air to enter. In addition, methane was used as fuel fed through the fuel feeder <NUM>.

A computational analysis code used was ANSYS-FLUENT <NUM>, a standard k-e model was used as a turbulence model, a discrete-ordinate model was used as a radiation model, and a skeletal model of <NUM> steps was used for chemical reaction.

As shown in <FIG>, it can be confirmed that, in the combustion heat generator <NUM> according to the present invention, through the oxidant injector <NUM>, the gas ejector <NUM>, and the fuel feeder <NUM> installed in the housing <NUM>, the first circulation region (A) and the second circulation region (B) are formed inside the combustion space <NUM>.

In particular, as shown in <FIG>, a fuel-rich region and a reaction activation region in the first circulation region (A) and the second circulation region (B) of the combustion space <NUM> may be identified from CO and OH concentration distributions.

That is, as shown in the computational analysis results, it can be confirmed that, the combustion heat generator <NUM> according to the present invention may ensure a uniform temperature distribution in an entire area except for air and a fuel jet in the combustion space <NUM>.

Claim 1:
A combustion heat generator (<NUM>) comprising:
a plate-shaped housing (<NUM>) having a combustion space (<NUM>) therein and two-dimensional flow is possible;
an oxidant injector (<NUM>) provided on a first position of the housing (<NUM>) and forming a first circulation region (A) by inputting an oxidant to an outer periphery of an inner side of the combustion space (<NUM>) through an oxidant injection nozzle (<NUM>) and circulating the oxidant;
a gas ejector (<NUM>) provided on a second position of the housing (<NUM>) and discharging a portion of gas circulating in the combustion space (<NUM>); and
a fuel feeder (<NUM>) installed to a central position of the housing (<NUM>) so that a front end of a fuel injection nozzle (<NUM>) is extended into the housing (<NUM>) and positioned in a second circulation region (B) formed in a center of the combustion space (<NUM>) by circulation of an oxidant in the first circulation region (A) to inject fuel into the second circulation region (B),
wherein the first position and the second position are formed on the same side of the housing (<NUM>) respectively,
wherein space combustion is generated in the combustion space (<NUM>) based on the second circulation region (B) and the fuel injected into the second circulation region (B) is turned while being gradually mixed with the oxidant circulating along the first circulation region (A).