JPH07158817A - Method and apparatus for heat exchanging operation while restricting generation of nox and co - Google Patents

Abstract

PURPOSE:To perform a heat exchanging operation while restricting generation of NOx and CO and eliminate a special combustion space by a method wherein a porous surface burner is arranged at one end of a heat exchanging device, a heat removing object is arranged to be substantially contacted with the burner. CONSTITUTION:A surface combustion burner 2 has a film-like flame at its surface, so that even if a thermal removing object 3 is substantially contacted with the burner 2, a high temperature part is already formed near the thermal removing object 3, resulting in that it can be effectively cooled. As heat is removed by the thermal removing object 3 designed to thermally absorb heat by about 15% of an entire heat generating amount, a flame temperature is restricted to a temperature of about 1200 deg.C or less. As a result, a value of NOx is restricted to about 30ppm or less. Generation of CO is also restricted. The flame having an amount of generation of NOx and CO enters a thermal insulating space 4 set to have a temperature of 1000 deg.C or higher and a residence time of 1/1000 second or more, is completely oxidized and then applied to a heat exchanging operation at the heat exchanging part 5. The heat exchanging operation can be carried out while an amount of generation of NOx and CO is being restricted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanging method and device for suppressing the generation of NOx and CO.

[0002]

2. Description of the Related Art It is known that NOx can be reduced by flame cooling by locating a water pipe near a burner. In this case, the closer the water pipe is brought to the burner, the more CO is generated, and the local overheating of the water pipe occurs. Therefore, in the heat exchange device, between the burner and the water pipe. A special combustion space of about 100 mm was constructed.

[0003]

In the above heat exchange device, heat exchange is performed while suppressing the generation of nitrogen oxides (NOx) and CO, and a compact combustion space is not required. The advent of heat exchangers is eagerly awaited.

[0004]

Means for Solving the Problems A porous surface burner is installed at one end of a heat exchange device, and a heat removal body is installed so as to be substantially in contact with the burner, and about 15% of the total calorific value is provided by the heat removal body. After the heat is removed, CO is completely burned in an adiabatic space capable of maintaining a residence time of 1/1000 seconds at 1000 ° C. or higher, and heat is exchanged by a heat exchange section thereafter. .

Further, according to the present invention, a porous surface burner is installed at one end of the heat exchanging device, a heat removal body is installed in substantially contact with the burner, and a heat insulating space is formed on the downstream side of the heat removal body. The heat exchanging portion is arranged on the downstream side of the heat insulating space.

[0006]

When the premixed gas introduced from the premixed gas introduction section starts burning in the surface combustion burner, about 15% of the total calorific value of the flame is removed by the heat removal body. as a result,
The flame temperature is, for example, about 1200 ° C. or lower, and NO
The x value is 30 ppm (O ₂ = 0% conversion) or less. Thus, it can be understood that the heat removal amount is low even though the burner and the heat removal body are substantially in contact with each other, and therefore the CO generation amount is not high. The generated CO is 1 at 1000 ° C or higher.
The combustion gas is completely oxidized in an adiabatic space capable of staying for one thousandth of a second or longer, and then the combustion gas is subjected to heat exchange in the heat exchange section.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference numeral 1 is a heat exchange device, and 2 is a porous surface combustion burner provided at one end thereof. The porous surface combustion burner 2 is made of ceramics or metal, and is a burner that forms a film-like flame on its surface. The heat removal body 3 is installed so as to substantially contact the surface combustion burner 2. The heat removal body 3 may be one through which a water pipe or other fluid passes. A heat insulating space 4 is formed on the downstream side of the heat removal body 3. The heat insulating space 4 is set to have a residence time of 1000 ° C. or more and 1/1000 second or more. Insulation space 4
The completely combusted combustion gas enters the heat exchange section 5 and is used for heat exchange.

Since the surface combustion burner 2 has a film-like flame formed on its surface, a high temperature portion is formed in the vicinity of the heat removal body 3 even if the heat removal body 3 substantially contacts the burner 2. Because
This can be cooled effectively, and since there is no special combustion space between the burner 2 and the heat removal body 3 as in the conventional case, the entire burner can be made compact. . Then, as shown in FIGS. 2 and 3, when the heat is removed by the heat removal body 3 designed to absorb about 15% of the total calorific value, the flame temperature is suppressed to about 1200 ° C. or less. . As a result, the NOx value is suppressed to about 30 ppm or less, and at the same time, the flame temperature becomes the allowable heat absorption amount of the heat removal body 3, whereby overheating of the heat removal body 3 can be prevented and the life is extended. Further, although the heat removal body 3 and the burner 2 are substantially in contact with each other, the amount of heat removal is lower than that in the case where the heat removal body 3 and the burner 2 are installed with a space therebetween, which means that at the same time, as shown in FIG. It can be understood that the generation of CO is also suppressed. The flame of which the generation amounts of NOx and CO are suppressed enters the adiabatic space 4 having the above-described configuration and is completely oxidized, and thereafter,
The heat is exchanged in the heat exchange section 5.

[0009]

Since the present invention is as described above, NOx
There is an excellent effect that heat exchange can be performed while suppressing the generation amount of CO and CO.

[Brief description of drawings]

FIG. 1 is a plan view of a heat exchange device of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a schematic diagram showing the position of a heat removal body and a combustion gas temperature.

FIG. 3 is an explanatory diagram showing a relationship between a heat removal amount and a NOx suppression value.

FIG. 4 is an explanatory diagram showing a relationship between a heat removal amount and a CO suppression value.

[Explanation of symbols] 1 heat exchange device 2 surface combustion burner 3 heat removal body 4 adiabatic space 5 heat exchange section

Claims (2)

[Claims] 1. A porous surface burner is provided at one end of a heat exchange device, and a heat removal body is installed in substantially contact with the burner, and after removing about 15% of the total calorific value by the heat removal body. , 1000
The heat exchange is performed while suppressing the generation of NOx and CO, which is characterized in that CO is completely combusted in an adiabatic space that can maintain a residence time of 1/1000 seconds above ℃, and then heat is exchanged by the heat exchange section. Method. 2. A porous surface burner is provided at one end of the heat exchange device, a heat removal body is installed in substantially contact with the burner, and a heat insulating space is formed on the downstream side of the heat removal device. A heat exchange device which suppresses the generation of NOx and CO, characterized in that a heat exchange section is formed on the downstream side of the.