JP2001056104A - Oxygen combustion once-through boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate heat absorption in a combustion chamber by a burner mounting method and the like, and simultaneously stabilize a water level and simplify a water level control system, and ensure the reasonable design for the combustion chamber. SOLUTION: An oxygen combustion once-through boiler is provided, in which a combustion chamber of a once-through boiler is constructed into a longitudinal cylindrical shape, and a burner 2 is installed below a boiler body by 1/2 to 1/5 of the height thereof. The boiler is disposed with a displacement from the center of the longitudinal cylindrical combustion chamber 1 by 0 to 1/2 of the outer diameter of the cylindrical combustion chamber 1 or by 0-3 times of the burner tip end diameter to form a burner flame tangential along a combustion chamber structure. Hereby, a simple flow pattern found in the prior art is formed to ensure excellent combustion and heat transfer and simple water level control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a once-through boiler for oxyfuel combustion, which enables simple combustion chamber design and simple water level control.

[0002]

2. Description of the Related Art In a conventional once-through boiler having a vertical cylindrical combustion chamber, a burner is installed at the center of an upper portion of a main body and burns. However, in this combustion method, the flow pattern of the flame and the combustion gas in the combustion chamber becomes complicated, and
Since the distribution of furnace load (heat transfer surface heat load) becomes uneven,
Complex combustion chamber design was required. In addition, in the above-described conventional boiler structure, the flow direction of the boiler water and the direction of the flame temperature or the height of the furnace load (heat transfer surface heat load) are reversed, so that the flow of the boiler water in the water pipe becomes unstable. ,
There was a problem that boiler water level control became complicated.

[0003]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the once-through boiler having the conventional vertical cylindrical combustion chamber, and secures good combustion and heat transfer. An object of the present invention is to realize a new and simple combustion chamber design and a simple water level control, which are new in the related art.

[0004]

Means for Solving the Problems In order to achieve the above object, a first aspect of the present invention is to install a water pipe of an oxyfuel combustion once-through boiler so as to form a cylindrical shape in a circumferential direction, and to provide a water pipe between water pipes. By welding with steel strip, providing a steam header at the top of the water pipe and a water chamber header at the bottom, a vertical cylindrical combustion chamber with a membrane structure is formed, a burner is installed on the side of the combustion chamber, and the burner installation part Is characterized by forming a flame in a horizontal direction with respect to a vertical cylindrical combustion chamber without providing a water pipe, and causing combustion gas to flow into a group of water pipes from a combustion gas outlet provided near a burner installation position. The second aspect of the present invention is that a burner is installed in the vertical cylindrical combustion chamber at a height of the boiler main body.
It is characterized in that it is installed at a lower part of about 1/5. The third aspect of the present invention is that the burner is installed eccentrically from the center of the vertical cylindrical combustion chamber to 0 to 1/2 of the outer diameter of the cylindrical combustion chamber or 0 to 3 times the center of the burner tip diameter, and the combustion is performed. It is characterized by forming a tangential burner flame along the chamber structure. A fourth aspect of the present invention is that the structure of the oxyfuel combustion once-through boiler enables good combustion, heat transfer, and simple water level control.
2. An oxygen combustion once-through boiler according to 2, 3, or 4.

[0005]

According to the oxyfuel combustion once-through boiler of the present invention, a burner is provided in a vertical cylindrical combustion chamber at a lower portion of one-fifth of the height of the boiler body and at a half of the outer shape of the cylindrical combustion chamber, or Since it is installed eccentrically from the center of 0 to 3 times the burner tip diameter, a tangential flow field by the flame and the combustion gas is formed in the combustion chamber. Since the flame formed in the combustion chamber is a short flame peculiar to oxyfuel combustion, the flame does not collide with the furnace wall, completes the combustion reaction in the semicircle on the burner mounting side, and the high-temperature gas in the remaining semicircle. And flows into the water tube group from the furnace outlet provided at the side of the burner mounting port to form an unprecedented simple flow pattern, enabling good combustion and heat transfer. Further, by the above, it is easy to eliminate local overheating of the heat transfer surface, and a substantially uniform furnace load (heat transfer surface heat load) can be obtained. As a result, heat absorption in the combustion chamber is facilitated by the burner mounting method and the like, and at the same time, the water level is stabilized, the water level control method is simplified, and a reasonable combustion chamber design becomes possible.

[0006]

FIG. 1 of the accompanying drawings is a side view of an oxygen-fired once-through boiler of the present invention. 1 is a vertical cylindrical combustion chamber, 2 is a burner installed on its side, 3 is a water pipe constituting the vertical cylindrical combustion chamber, 4 is a steel strip installed between the water pipes, and 5 is provided on the upper part of the water pipe. The steam header 6 is a water chamber header provided at the lower part of the water pipe, and has an oxygen combustion once-through boiler having this structure. In the figure, H1 is the height of the main body,
H2 indicates the installation height from the center of the main body to the burner 2. The following relationship is established between the main body height H1 and the burner installation height H2. H2 = 1/2 × H1１ ／ 1/5 × H1 FIG. 2 is a plan view of the oxyfuel combustion once-through boiler, where W1 is the outer diameter of the cylindrical combustion chamber, W2 is the burner tip diameter, and W3 is the eccentric installation distance of the burner. The following relationship is established between the eccentric installation distance W3, the cylindrical diameter W1, and the burner tip diameter W2. W3 = 0 × W1１〜1 / 2 × W1 and W3 = 0 × W2-3 × W2 FIG. 3 shows the flow pattern of the flame and the combustion gas in the combustion chamber of the oxyfuel once-through boiler. By installing a burner in the vertical cylindrical combustion chamber with the above dimensions, a tangential flow field is created in the combustion chamber by the flame and the combustion gas. Since the flame formed in the combustion chamber is a short flame peculiar to oxyfuel combustion, the flame does not collide with the furnace wall, completes the combustion reaction in the semicircle on the burner mounting side, and the high temperature occurs in the remaining semicircle. It is filled with gas and flows into the water pipe group from the furnace outlet provided at the side of the burner mounting port, forming an unprecedented simple flow pattern, enabling good combustion and heat transfer. Further, by the above, it is easy to eliminate local overheating of the heat transfer surface, and a substantially uniform furnace load (heat transfer surface heat load) can be obtained. As a result, the heat absorption in the combustion chamber is facilitated by the burner mounting method and the like, and the water level is stabilized and the water level control method is simplified.
There is an advantage that a reasonable combustion chamber design is possible.

[0007]

According to the present invention, in the oxyfuel combustion once-through boiler, the burner of this setting is provided in the vertical cylindrical combustion chamber at a height two to one-fifth below the height of the boiler main body and at the center of the vertical cylindrical combustion chamber. By eccentrically installing from the center of the outer diameter of the combustion chamber 0 to 1/2 or 0 to 3 times the center diameter of the burner tip, the flow pattern of the flame and the combustion gas in the combustion chamber is simplified, resulting in good combustion and transmission. Heat is made possible, and as a result, there is an effect that an unprecedentedly simple combustion chamber design and simple water level control become possible.

[0008]

[Brief description of the drawings]

FIG. 1 is a side view of an oxygen combustion once-through boiler.

FIG. 2 is a plan view of an oxygen combustion once-through boiler.

FIG. 3 shows a flow pattern of a flame and a combustion gas in a combustion chamber of an oxyfuel once-through boiler.

[Explanation of symbols]

 Reference Signs List 1 vertical cylindrical combustion chamber 2 burner installed on side of vertical cylindrical combustion chamber 3 water pipe constituting vertical cylindrical combustion chamber 4 steel strip installed between water pipes 5 steam header provided above water pipe 6 water pipe Water chamber header provided at the bottom

Claims (4)

[Claims] In a once-through boiler, a water pipe is installed so as to form a cylindrical shape in a circumferential direction, a space between the water pipes is welded by a steel strip, a steam header is provided at an upper part of the water pipe, and a water chamber header is provided at a lower part. As a result, a vertical cylindrical combustion chamber with a membrane structure is formed, and a burner for oxyfuel combustion (hereinafter referred to as a burner) is installed on the side of the combustion chamber. An oxyfuel combustion once-through boiler, characterized in that a flame is formed in a horizontal direction, and combustion gas flows into a group of water pipes from a combustion gas outlet provided near a burner installation position. 2. The once-through boiler for oxyfuel combustion according to claim 1, wherein the burner is installed in the vertical cylindrical combustion chamber at a position lower than one-fifth of the height of the boiler body. 3. A combustion chamber having an outer diameter of 0 to 1/2 of the outer diameter of the cylindrical combustion chamber from the center of the vertical cylindrical combustion chamber, or 0 to 0 of the tip diameter of the burner.
2. The once-through boiler for oxyfuel combustion according to claim 1, wherein the boiler is disposed eccentrically from the center of three times to form a tangential burner flame along the combustion chamber structure. 4. Due to the boiler structure and the short flame peculiar to oxyfuel combustion according to claims 1 to 3, the combustion reaction is completed in the semicircular portion on the burner mounting side without the flame colliding with the furnace wall, and the other half. High-temperature gas is filled in the circle and flows into the water tube group from the furnace outlet provided next to the burner mounting port, forming an unprecedented simple flow pattern, enabling good combustion, heat transfer, and simple water level control. An oxygen-fired once-through boiler, characterized in that: