JPH0646101U - Mounting structure of heat transfer surface in combustion chamber of circulating fluidized bed apparatus - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a structure for mounting a heat transfer plate that is not affected by the arrangement due to the difference in temperature rising rate and temperature distribution depending on the part during operation of the circulating fluidized bed apparatus. In a structure for mounting a heat transfer plate in a combustion chamber in which a heat transfer plate 8 in which water tubes are arranged is inserted laterally from a lower position of the combustion chamber 1 and then vertically penetrated along a wall surface of the combustion chamber. The lower header 9 of the heat transfer plate was fixed to the outer wall of the combustion chamber, and a tension device for pulling the upper header 10 of the heat transfer plate protruding through the top of the combustion chamber upward was attached. Since the lower base is fixed and the top of the straight pipe section 13 extending up to 30 m is movably provided, deformation due to partial temperature change can be released freely above the straight line section, so temperature change during operation Also, the relative position of the heat transfer plate 8 in the combustion chamber does not change,
Enables stable operation.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mounting structure for a heat transfer surface in a combustion chamber of a circulating fluidized bed apparatus which burns coal powder or the like in a circulating fluidized bed to exchange heat.

[0002]

[Prior art]

 Combustion devices that use fluidized beds are used in various fields, taking advantage of the ability to efficiently burn a variety of fuels under stable conditions. In addition to low SOx emissions because it is possible, low temperature NOx emissions are possible because low-temperature combustion is possible, and desulfurization and denitration facilities outside the reactor are not required. Wide range of coal from bituminous coal to semi-anthracite coal. It is widely used as a boiler for in-house power generation in the industrial field, because it has many merits that it can be used as fuel, it has a wide variety of fuels, and the equipment itself has excellent reliability.

As shown in FIG. 3, this circulating fluidized bed apparatus includes a combustion chamber 1 for burning a fuel mainly composed of powder fuel, a particle circulation system including a hot cyclone 2 and a sealing mechanism 3, and a superheater. It consists of three main parts of the rear convection heat transfer structure consisting of 4, the economizer 5, and the air preheater 6. In the combustion chamber 1, coal powder, coal ash, and lime powder for desulfurization are used as an example of circulating particles. The primary combustion air and the secondary combustion air are blown from the nozzle that is thrown in and installed in the lower part of the combustion chamber to form a fluidized bed. The circulating particles, after leaving the combustion chamber 1, are collected by the hot cyclone 2 and recirculated to the combustion chamber 1 via the sealing mechanism 3 formed of a pneumatic valve, while the flue gas leaving the hot cyclone 2 is collected. After passing through the duct 7, the heat is exchanged in the convection heat transfer section of the wake, and the dust is collected by a dust collector such as a bag filter and then discharged from the chimney through the induced draft fan.

In order to make full use of this advantage, various improvements in operation and structure have been added. For example, JP-B-57-28046, JP-B-59-13644, and JP-A-59-179290. Japanese Patent Laid-Open No. 59-197724 and the like disclose that operating efficiency can be improved by defining operating conditions such as the particle size of circulating coal powder. In addition, JP-A-2-122826, JP-A-3-95303, JP-A-3-102101 and the like propose improvements in the convection heat transfer structure on the wake side.

In the combustion chamber 1 which controls approximately 50% of the heat exchange function of this circulating fluidized bed apparatus, a heat transfer plate 8 in which water tubes are arranged is provided in a dense bed with a dense fluidized particle density in order to improve the boiler function. The lower header 9 is fixed from the outer wall to the upper part of the region while being inserted from the side, and then the upper header 10 is inserted into the outer shell of the combustion chamber 1 while vertically penetrating along the wall of the combustion chamber 1. There is a form in which is fixed to the top.

[0006]

[Problems to be solved by the device]

 However, in this type of heat transfer plate arrangement, the temperature rising rate at the start-up of the equipment and the absolute temperature rise during operation are uniform between the center and the top of the combustion chamber during operation of the circulating fluidized bed equipment. However, the heat transfer plate having a height of about 30 m is considerably deformed. Therefore, there is a problem that the local deformation of the pipes forming the heat transfer plate cannot be properly absorbed and abnormal deformation of the pipes occurs, or in some cases, the generated stress due to the deformation of the pipes exceeds the allowable stress, leading to breakage.

An object of the present invention is to provide a mounting structure for a heat transfer plate that is not affected by the arrangement of the circulating fluidized bed apparatus due to the difference in temperature rising rate and temperature distribution during operation. .

[0008]

[Means for Solving the Problems]

 The present invention is a mounting structure for a heat transfer plate in a combustion chamber in which a heat transfer plate with water tubes arranged is inserted laterally from a lower position of the combustion chamber and then vertically penetrated along a wall surface of the combustion chamber. In the above, the lower header of the heat transfer plate is fixed to the outer wall of the combustion chamber, and at the same time, the circulating fluidized bed apparatus is equipped with a tension device for pulling the upper header of the heat transfer plate that penetrates the top of the combustion chamber upward. This is the mounting structure for the heat transfer surface in the combustion chamber.

[0009]

[Action]

 The lower base is fixed, and a tension device is installed on the top of the straight pipe part that extends up to 30 m, and the heat transfer plate is pulled by a constant tension above the straight part due to deformation due to partial temperature change, so during operation Even if the temperature of the heat transfer plate changes, it is possible to prevent local deformation, abnormal deformation, and even breakage of the heat transfer plate in the combustion chamber.

[0010]

【Example】

 FIG. 1 shows an embodiment of a combustion chamber 1 of a circulating fluidized bed apparatus to which a heat transfer plate mounting structure according to the present invention is applied.

The heat transfer plate 8 formed by arranging the water pipes 11 has a short lower horizontal portion 12 and a long vertical portion 13 and the lower header 9 attached to the base of the lower horizontal portion 12 is Similar to the case shown in FIG. 3, it is fixed to the wall of the combustion chamber 1, and the upper end of the vertical portion 13 is movably attached to the top of the combustion chamber 1 together with the upper header 10 at the upper end.

FIG. 2 shows a movable mounting structure at the top of the heat transfer plate 8.

The heat transfer plate 8 penetrates the top of the combustion chamber 1 and the wall of the convection section 20 above the combustion chamber 1 and is connected to the upper header 10. The pressure in the combustion chamber 1 is completely sealed by the lower seal box 14 and the upper seal box 15.

The relative displacement of the heat transfer plate 8 caused by fixing the lower header 9 to the combustion chamber wall is absorbed by the bellows 16 attached to the upper seal box 15. Further, the upper header 10 is connected to a constant hanger (heat transfer plate tension device) 17 installed on a frame 18 so that it is always held at a constant tension. Further, the connecting pipe 19 from the upper header 10 forms a loop, and is designed so as to completely absorb the displacement of the upper header 10. Further, it goes without saying that the lower seal box 14 is not necessary in an embodiment not described in which the convection section 20 is not located above the top of the combustion chamber 1.

With the above structure, the upper end of the heat transfer plate 8 can freely move with respect to the temperature change of the heat transfer plate 8 during the operation of the circulating fluidized bed apparatus, and the deformation in the combustion chamber can be prevented.

[0016]

[Effect of device]

 The present invention has the following effects.

(1) The reliability of the device is increased by stabilizing the structure of the heat transfer plate.

(2) Disturbance of the flow of circulating particles due to deformation during operation of the long heat transfer plate in the combustion chamber can be prevented, the flow of circulating particles becomes constant, and stable operation of the device itself becomes possible.

[Brief description of drawings]

1 shows a sectional structure of a combustion chamber embodying the present invention.

FIG. 2 shows a movable mounting structure on an upper portion of a heat transfer plate.

FIG. 3 shows an outline of a conventional circulating fluidized bed apparatus.

[Explanation of symbols]

 1 combustion chamber 2 hot cyclone 3 sealing mechanism 4 superheater 5 economizer 6 air preheater 7 duct 8 heat transfer plate 9 lower header 10 upper header 11 water pipe 12 lower horizontal part 13 vertical part 14 lower seal box 15 upper seal box 16 Bellows 17 Constant hanger 18 Frame 19 Connecting pipe 20 Convection section

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Kazuhiro Takeshita Kazuhiro Takeshita 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Co., Ltd. Technology Development Headquarters 59 Nittetsu Plant Design Co., Ltd. (72) Genji Fujita Inventor, Genji Fujita At 59 Nakahara, Tobata-ku, Kitakyushu City, Fukuoka Prefecture 59, Nippon Steel Plant Design Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A mounting structure for a heat transfer plate in a combustion chamber, wherein a heat transfer plate in which water tubes are arranged is laterally inserted from a lower position of the combustion chamber, and then is vertically penetrated along a wall surface of the combustion chamber. , A combustion chamber of a circulating fluidized bed apparatus in which a lower header of the heat transfer plate is fixed to an outer wall of a combustion chamber, and a tension device for pulling an upper header of the heat transfer plate penetrating to the top of the combustion chamber is pulled upward Mounting structure of heat transfer surface in.