JP2574481Y2 - Fluidized bed heat exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an improvement of a fluidized bed heat exchanger.

[Conventional technology]

As shown in FIG. 3, for example, a conventional fluidized bed heat exchanger of this type has a gas inlet 20a at a lower end and a gas outlet 20b at an upper end.
A casing 20 having a gas flow passage therein and extending substantially vertically, a perforated plate 22 horizontally disposed in the casing 20 and formed with a large number of ventilation holes, and a perforated plate 22 in the casing 20. And a solid particle layer 23 formed to have an appropriate thickness.

The casing 20 is provided with a heat transfer tube 24 for transferring water as a fluid to be heated. The heat transfer tube 24 is formed of a substantially U-shaped pipe, and its curved portion 24c is exposed to the outside of the casing 20, and the two parallel portions 24a and 24b are attached so as to pass through the gas flow path. One parallel part 24a
Is disposed in the solid particle layer 23, and the other parallel portion 24b is
It is arranged above the solid particle layer 23. The tip of the one parallel portion 24a is the water inlet 25, and the other parallel portion 24ba
Is formed as a water outlet 26. Helical fins 27 are attached to the outer peripheral surfaces of the parallel portions 24a and 24b for efficient heat exchange.

The gas inlet 20a is connected to, for example, an exhaust gas discharge system of a diesel engine, and the water inlet 25 and the water outlet 26 are connected to, for example, a hot water or steam circulation system of a boiler.

In the fluidized bed heat exchanger having the above configuration, during operation, high-temperature exhaust gas flows through the casing 20 through the gas inlet 20a.
From the gas outlet 20b. At this time, since the exhaust gas is ejected from below the perforated plate 22 into the solid particle layer 23, the solid particle layer 23 is vigorously stirred and heated to form a fluidized bed. On the other hand, the two parallel portions 24a, 24b of the heat transfer tube 24
Are both in this fluidized bed,
The water flowing into the heat transfer pipe 24 is heated by the fluidized bed while flowing through the heat transfer tube 24, and then leaves the water outlet 26.

[Problems to be solved by the invention]

Meanwhile, a helical fin 27 is attached to the heat transfer tube 24 used in the conventional fluidized bed heat exchanger in order to improve a heat transfer area. As shown in FIG. 7, a fin material 27 'in the form of a strip is spirally wound around the surface of the heat transfer tube 24, and the fin material 27' and the heat transfer tube 24 are fixed by a fixing method such as spot welding.

In such a heat transfer tube 24, a strip-shaped fin material is used.
When wrapping the fin material 27 ′ around the heat transfer tube 24,
Wrinkles are formed on the inner peripheral side of the
28 will occur. When such a wrinkle 28 occurs, the interval becomes narrower than the actual pitch of the fins at this portion. Therefore, when the heat exchanger is operated, the heat transfer particles constituting the solid particle layer (in a fluidized state) are formed. However, the above-mentioned portions are clogged, resulting in a decrease in a heat transfer area and an increase in resistance to a gas flow, thereby lowering a heat recovery rate.

If the winding pitch of the fin material 27 'is widened in order to prevent the above-described clogging, the heat transfer area per unit length of the heat transfer tube 24 is reduced, and the heat recovery efficiency is reduced. Further, instead of the above-mentioned helical fin 27, a flat fin may be used, and a heat transfer tube 24 may be collectively penetrated and attached to the flat fin, but in such a fluidized bed heat exchanger. Cannot expect improvement in heat recovery efficiency.

[Means for solving the problem]

This invention was made in order to solve the above-mentioned problem, and a gas flow path through which gas flows upward from below, a perforated plate arranged in this gas flow path, and a gas In a fluidized bed heat exchanger having a solid particle layer that is in a fluidized state when flowing through and a heat transfer tube in contact with the solid particle layer, a plurality of parallel portions of the heat transfer tube are arranged in a plurality of stages in the gas flow direction. A large number of flat fins are provided on the outer periphery of each parallel portion independently for each parallel portion such that the bottom side thereof is substantially orthogonal to the gas flow, and each flat fin is placed adjacent to the parallel portion. The fins are arranged so as to be shifted by a half pitch between the fins, and are arranged such that the tips of the plate-like fins are close to the adjacent parallel portions.

[Action]

According to the fluidized-bed heat exchanger according to the present invention, the heat transfer tube is provided with a large number of flat fins, thereby preventing clogging of the heat transfer particles constituting the fluidized bed between the flat fins.

Furthermore, a plurality of parallel portions of the heat transfer tube are arranged in a plurality of stages in the gas flow direction, and a large number of flat fins are provided on the outer periphery of each of the parallel portions so that the bottoms thereof are substantially orthogonal to the gas flow. By providing each parallel part independently,
The flow of the heat transfer particles is disturbed at the bottom of each flat fin, and the heat transfer efficiency is kept high. Further, the heat transfer fins are arranged such that the arrangement pitch thereof is shifted by half a pitch between the adjacent parallel portions, and the heat transfer fins are arranged in a state where the tips of the plate-like fins are close to the adjacent parallel portions. In addition, the heat transfer area per unit occupied space can be widened, and the heat recovery amount can be increased.

〔Example〕

FIGS. 1 and 2 show an embodiment of a fluidized bed heat exchanger according to the present invention, in which a substantially vertically extending casing 20 having an internal gas flow path and a substantially horizontal casing 20 are provided. Perforated plate with a large number of ventilation holes
22 and a solid particle layer 23 formed on the perforated plate 22 in the casing 20 to have an appropriate thickness.

The casing 20 is provided with a heat transfer tube 1 for transferring water as a fluid to be heated. The heat transfer tube 1 is composed of a plurality of substantially U-shaped pipes, and the same side ends of these pipes are connected to headers 2 and 3, respectively. Of the headers 2, 3, a water inlet 4 is provided in the lower header 2, and a water outlet 5 is provided in the upper header 3.

The parallel portions 1a and 1b of each pipe are arranged in a plurality of stages (two stages in the illustrated embodiment) in the gas flow direction, and the parallel portions 1a and 1b are arranged in a zigzag manner.

Each of the two parallel portions 1a, 1b of each pipe has a respective parallel portion 1a,
A large number of flat fins 6, 6, ... are attached at a predetermined arrangement pitch by welding independently for each 1b. Each of the flat fins 6 is fixed as a pair so as to face each other from both upper and lower sides in the radial direction of each pipe. In this state, each of the flat fins 6 has a rectangular shape centered on the pipe. It has become. Further, the bottom of each of the flat fins 6 is
They are arranged so as to be substantially horizontal, so that the bottom is substantially orthogonal to the flow direction of the exhaust gas.

The plate-like fins 6 are arranged so as to be shifted by half a pitch between adjacent parallel portions 1a and 1b, for example, between the parallel portions 1a and 1b adjacent in the horizontal direction, and the tips of the plate-like fins 6 are adjacent to each other. It is arranged so as to be close to the parallel parts 1a and 1b. That is, the flat fins 6 alternately overlap in the axial direction of the parallel portions 1a and 1b in the adjacent parallel portions 1a (and 1b), whereby the heat transfer area per unit occupied area is Extremely large.

Further, in this embodiment, each of the parallel portions 1a, 1b
At both ends, holder members 7a and 7b and flange members 8a and 8b are provided to facilitate attachment to the casing 20, and the heat transfer tubes 1 are connected to each other to form one unit.

A set (7a) of each of the holder members 7a, 7b and the flange members 8a, 8b
, 8a, 7b and 8b) are provided such that the holder members 7a and 7b are located on the curved portion 1c side of the heat transfer tube 1, and the outer dimensions of the respective members are smaller as the members are closer to the curved portion 1c. It is set to become. On the other hand, window holes 9a and 9b corresponding to the holder members 7a and 7b are formed in the casing 20.
Therefore, by inserting the curved portion 1c of the heat transfer tube 1 first from the large window hole 9b side, the heat transfer tube 1 can be mounted at a predetermined position, and the heat transfer tube 1 is inspected and repaired. Extremely high desorption workability.

Now, in the fluidized bed heat exchanger having the above configuration, during operation, high-temperature exhaust gas is supplied to the casing 10 as described above.
The exhaust gas flows through the inside of the solid particle layer 23 from below the perforated plate 22.
The solid particle layer 23 is vigorously agitated and heated in order to eject the fluid into the inside, and a fluidized bed is formed. In this fluidized bed heat exchanger, the plate-like fin 6 attached to the heat transfer tube 1 is a plate-like member of a predetermined thickness. Also, wrinkles 28 unlike the helical fins 27 in the conventional device do not occur. Therefore, it is possible to prevent the heat transfer particles constituting the fluidized bed from being clogged between the bases of the fins during operation, thereby preventing a decrease in the heat transfer area and an increase in resistance to the gas flow as in the related art. High heat efficiency can be maintained and stable heat recovery can be achieved.

Further, the plate-like fins 6 are arranged so as to be shifted by half a pitch between the adjacent parallel portions 1a and 1b, and the leading end of each plate-like fin 6 is arranged so as to be close to the adjacent parallel portions 1a and 1b. Therefore, the heat transfer area per unit occupied space becomes extremely large, and the heat transfer performance can be improved.

In addition, in the present invention, by adopting the above-described configuration, the same effect as reducing the arrangement pitch of the flat fins 6 in the entire fluidized bed heat exchanger can be obtained.
The arrangement pitch of the fins with respect to each of the parallel portions 1a and 1b can be made equal to or larger than that of the conventional art, so that the production cost can be reduced and the production workability can be improved.

Further, since the fins are configured as described above, the degree of freedom of the fin shape is higher than that of the conventional helical fin 27 in which the fin material 27 'is wound around the heat transfer tube 24 and fixed, as in the illustrated embodiment. , Each parallel portion 1a, 1 of the heat transfer tube 1
By selecting and attaching a shape that is substantially rectangular with respect to b, the heat transfer area per unit space can be improved, and higher heat transfer efficiency can be obtained.

Furthermore, since each of the flat fins 6 is provided independently for each of the parallel portions 1a and 1b so that the bottom side thereof is substantially orthogonal to the flow of the exhaust gas, the flat fins 6 flow by the exhaust gas. The heat transfer particles are formed in the respective flat fins 6.
The flow is disturbed at the bottom of the, and the heat exchange efficiency is further improved.

Further, by arranging the parallel portions 1a and 1b of the heat transfer tube 1 in a staggered manner, a short path of exhaust gas can be prevented, the entire heat transfer surface can be effectively operated, and the heat transfer efficiency can be maintained high. it can.

[Effect of the invention]

As described above, the fluidized bed heat exchanger according to the present invention has a configuration in which a large number of flat fins are attached to a heat transfer tube. It is possible to reliably prevent the heat transfer particles constituting the fluidized bed from being clogged.

Further, each of the flat fins is provided on each of the parallel portions arranged in a plurality of stages in the gas flow direction, in a state independent of each parallel portion such that the base is substantially orthogonal to the gas flow. Therefore, the heat transfer particles flowing by the gas are disturbed at the bottom of each of the flat fins,
The heat exchange efficiency is further improved.

Further, the flat fins are arranged so as to be shifted by a half pitch between the parallel portions of the adjacent heat transfer tubes, and the leading end of each flat fin is arranged so as to be close to the adjacent parallel portion. The heat transfer area per occupied space is extremely large, and the heat transfer performance can be improved.

Therefore, according to the present invention, it is possible to prevent a decrease in the heat transfer area due to the clogging of the heat transfer particles and an increase in resistance to the gas flow, and it is possible to stably recover heat while maintaining a high heat transfer efficiency.

[Brief description of the drawings]

1 and 2 show an embodiment of a fluidized bed heat exchanger according to the present invention. FIG. 1 is a schematic side view, and FIG.
The figure is a sectional view of a main part of the heat transfer tube. FIG. 3 is a schematic diagram showing an example of a conventional fluidized bed heat exchanger, and FIGS. 4 (a) and 4 (b) are enlarged views of a main part of the conventional fluidized bed heat exchanger. DESCRIPTION OF SYMBOLS 1 ... Heat transfer tube 1a ... Parallel part 1b ... Parallel part 4 ... Fluid inlet 5 ... Fluid outlet 6 ... Flat fin 22 ... Perforated plate 23 ... Solid particle layer

Claims (1)

(57) [Scope of request for utility model registration] 1. A gas flow path through which a gas flows upward from below, a porous plate 22 disposed in the gas flow path, and solid particles which are in a flowing state on the porous plate 22 when a gas flows. In a fluidized bed heat exchanger having a layer 23 and a heat transfer tube 1 in contact with the solid particle layer 23, a plurality of parallel portions 1a and 1b of the heat transfer tube 1 are arranged in a plurality of stages in the gas flow direction, On the outer periphery of each of the parallel portions 1a and 1b, a large number of flat fins 6 are provided independently for each of the parallel portions 1a and 1b so that the bases thereof are substantially orthogonal to the gas flow. 6 are arranged so as to be shifted by a half pitch between the adjacent parallel portions 1a and 1b, and the tips of the flat fins 6 are connected to the adjacent parallel portions 1a and 1b.
A fluidized bed heat exchanger, wherein the heat exchanger is disposed close to b.