JPS636318A - Burner - Google Patents

Abstract

PURPOSE:To enable a superior combustion characteristic to be got even under a low loading condition of a boiler of low capacity and to keep a high efficiency of boiler by a method wherein an automatic varying device for adjusting increase or decrease in opening area of a burner throttle port in response to a burner load is arranged. CONSTITUTION:In an automatic varying device 14, a guide ring 15 is rotatably arranged in a burner throttle port 13 and a plurality of guide grooves 18 having a desired slant angle are punched in equally-spaced apart relation. At each vane 16 are vertically arranged drive pins 19 which are inserted into the guide grooves 18 and can be moved along the guide grooves 18. A driving mechanism 17 is automatically controlled in such a way as it is properly operated in response to a burner load. When the guide ring 15 is reversely rotated by the driving mechanism 17, each of the vanes 16 is moved outwardly or inwardly of the guide ring 15 under cooperation of the guide grooves 18 and the driving pins 19 so as to increase or decrease the opening area of a burner throttle port 13. With this arrangement, even under a low burner load, a flow speed of combustion air is maintained at a proper value and a superior combustion characteristic can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a combustor that is mainly installed in a small-capacity boiler and that appropriately mixes and burns seven fuels such as liquid and combustion air.

(Prior Art) Generally, in a combustor installed in a small capacity boiler, the diameter of the burner orifice cannot be changed. As a result, as the burner load becomes heavier, the amount of combustion air required for this combustor decreases, resulting in a decrease in the flow rate of combustion air and deterioration of combustion characteristics. Therefore, in a small-capacity boiler equipped with the combustor, when the boiler load becomes light (less than 50%),
The combustor must be controlled by repeating combustion and extinguishing, and when extinguishing, a large amount of heat is released from the flue, resulting in a significant drop in boiler efficiency. In addition, since the combustor repeats combustion and extinguishing many times, the mechanical and electrical life of each comb type is also shortened.

Therefore, as a means to solve the above problem, it is possible to use a proportional combustor for the combustor, or to reduce the diameter of the burner orifice of the combustor to increase the flow rate of combustion air even under light loads. There is a way to maintain it.・However, small capacity boiler 1
In this case, a proportional combustor is expensive, and if the diameter of the burner contact port is made small, the pressure loss of the combustion air at the burner outlet during high loads increases, making it difficult to supply combustion air. The blower requires excessive power, which poses problems in terms of cost, noise, and power consumption.

(Problems to be solved by the invention) The present invention was devised to solve the above problems, and its purpose is to obtain good combustion characteristics even under low load of a small capacity boiler. In addition, it is an object of the present invention to provide a combustor that can maintain high boiler efficiency.

(Means for Solving the Problems) The combustor of the present invention is characterized in that it is provided with an automatic variable device that increases or decreases the opening area of the burner orifice in accordance with the burner load.

(Function) When a small capacity boiler equipped with the combustor is operated, the combustor automatically increases or decreases the opening area of the burner orifice according to the burner load using an automatic variable device to control the flow rate of combustion air. Maintain proper directness. As a result, good combustion characteristics can be obtained over a wide load range, and high boiler efficiency can be obtained even when the boiler is under low load.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a schematic vertical sectional view of a small once-through boiler (equivalent evaporation amount: 1800 Kf/H) equipped with a combustor 1 according to an embodiment of the present invention, and the boiler consists of a casing 2, an upper refractory 3, and a lower part. It is composed of a refractory 4, a furnace 5, a water pipe 6, a combustor 1, etc.

The combustor 1 according to the present invention includes a wind box 7, a burner inlet guide vane 8, a fuel injection pipe 9, a draft tube 10, a blower 11. Ignition electrode 12, burner aperture 13
and an automatic variable device 14, etc., and the structure other than the automatic variable device 14 is similar to that of conventionally known devices.

The automatic variable device 14 is installed at the burner aperture 13 and automatically increases or decreases the opening area of the burner aperture 13 in accordance with the burner load.

Specifically, the automatic variable device 14 is configured as shown in FIGS.
As shown in the figure, it is comprised of a guide ring 15, a plurality of approximately crescent-shaped vanes 16, a drive mechanism 17, and the like.

That is, the guide ring 15 is rotatably disposed within the burner throttle port 13, and a plurality of guide grooves 18 having a predetermined inclination angle are bored at equal intervals. , is rotatably supported within the burner orifice 13 and on the upper refractory 3 by appropriate means,
A driving pin 19 is provided upright on each vane 16 so as to be inserted into the guide groove 18 of the guide ring 15 and move along the guide groove 18 .

Furthermore, Kuri i1t! I al Purchase 17 C, motor 20
+2: The attached output gear 21, the intermediate gear 22 that meshes with the output gear 21, and the intermediate gear 2
2 and the guide ring 15
The guide ring 15 is rotated forward and backward by an appropriate amount. This blade motor unit 17 is automatically controlled by an appropriate control device (not shown) to operate appropriately according to the burner load.

Note that the guide groove 18 of the guide ring 15 is
The drive pin 19 of each vane 16 is moved along the guide groove 18 when rotated in forward and reverse directions, and each vane 16 is formed in such a shape that it is moved inward and outward of the guide ring 15, respectively.

Therefore, when the guide ring 15 is rotated in the forward and reverse directions by the drive device 17, each vane 16 moves inwardly and outwardly of the guide ring 15 due to the cooperation between the guide groove 18 and the drive pin 19. will be increased or decreased.

In the small once-through boiler, the combustion air blown by the blower 11 is swirled by the burner inlet guide vane 8 and mixed with the fuel injected from the fuel outlet of the fuel injection pipe 9. It flows out into the furnace 5 through the burner orifice 13 while forming a flame. At this time, in the combustor 1, the automatic variable device 14 operates according to the burner load to increase or decrease the opening area of the burner opening 13. As a result, even when the burner is under low load, the flow rate of combustion air is maintained at an appropriate level, resulting in good combustion characteristics.

4 and 5 are graphs comparing the combustion characteristics of a conventional combustor with a non-variable burner orifice diameter and a combustor 1 according to the present invention when used in the small once-through boiler, respectively. The combustion characteristics of the combustor 1 according to the present invention shown in the real image are significantly improved at low burner loads compared to the combustion characteristics of the conventional combustor shown in broken lines.

As a result, if the combustor 1 according to the present invention is used, continuous combustion is possible up to a boiler load of 25%, and as shown by the solid line in the graph of FIG. The boiler efficiency at 25% load is approximately 35% compared to the boiler efficiency when a conventional combustor is installed, which uses a control method that repeats combustion and extinguishing of the combustor for boiler loads of 50% or less. It has been improved. Therefore, fuel consumption will be saved by 10,000 to 420,001 per year using A heavy oil.

In the above embodiment, the automatic variable device 1 of the combustor 1
4 is composed of a guide ring 15, a vane 16, and a recognition mechanism 17, but the automatic variable device 14 is not limited to that of the above embodiment, and can adjust the opening area of the burner orifice 13 according to the burner load. The structure, shape, etc. are arbitrary as long as the increase or decrease can be automatically adjusted using You may also attach it.

(Effects of the Invention) As described above, the combustor of the present invention is equipped with an automatic variable device that can increase or decrease the opening area of the burner orifice in accordance with the burner load, so even when the burner load is low, the combustor can be used for combustion. Air flow velocity can be maintained at an appropriate value, resulting in good combustion characteristics. As a result, high boiler efficiency can be obtained even when the boiler is under low load, and fuel savings and cost reductions can be achieved.

In addition, when the combustor of the present invention is put into practice, continuous combustion is possible even when the boiler is under low load, so the combustor's combustor efficiency is reduced compared to conventional control systems that repeatedly burn and extinguish the combustor during low boiler loads. Combustion and extinguishing are greatly improved, and the mechanical and electrical life of each device is greatly extended.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical sectional view of a small once-through boiler equipped with a combustor according to an embodiment of the present invention, FIGS. 2 and 3 are perspective views of an automatic variable device for the combustor, and FIGS. 4 and 5 Figure 6 is a graph comparing the combustion characteristics of a conventional combustor and a combustor according to the present invention installed in a small once-through boiler, respectively. This is a graph comparing the boiler efficiency of the two installed in the boiler. 01 is the combustor, 13 is the burner throttle, and 14 is the variable device. Patent applicant Takuma Co., Ltd. Representative Junkichi Fukuda

Claims (1)

[Claims] A combustor characterized by being provided with an automatic variable device (14) that increases or decreases the opening area of a burner orifice (13) in accordance with burner load.