JPH0631284Y2 - Square multi-tube once-through boiler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an improvement of a can body of a type in which combustion gas is allowed to flow in a direction intersecting with a group of water tubes arranged in tandem.

[Conventional technology]

In recent years, in the multi-tube type once-through boiler, various types based on a so-called rectangular can body structure have been proposed in order to reduce the size of the boiler itself and save space. The once-through boiler has water tubes arranged in an oval or rectangular shape and has a structure that has a relatively large space as a combustion chamber.Therefore, there is a limit to the miniaturization of the can body and further space saving. Is difficult to achieve.

Therefore, as a solution to the above-mentioned problems, the applicant has arranged a plurality of water pipes in parallel and in close proximity to each other in a column, and a multi-tube type in which combustion gas is circulated in a crossing direction with respect to these water pipes. Proposing a once-through boiler (Practical application Sho 63-
No. 107336) [Jitsukai Sho 2-28902].

[Problems to be solved by the device]

As shown in Fig. 4, the above-mentioned square multi-tube once-through boiler has a first distance from the combustion burner (1) at a predetermined distance.
Arrange the water pipe row (A) of this, and the water pipes of this and other rear rows (B), (C)…
(2) and the gap and the gap between the left and right water pipes are set to be substantially equal to or smaller than the water pipe diameter d, and the water pipe rows are set.
(A), (B), (C) ... are arranged in the flow direction of the combustion gas.

However, when the number of water tubes in each water tube row is reduced in order to apply the above can body structure to a boiler having a smaller capacity, there are the following disadvantages.

(1) For example, two water pipe rows (A), (B), (C), etc. are arranged in close contact with each other to form two rows of water pipe walls in the flow direction of the combustion gas, and combustion is performed between them. When the gas is made to flow,
As shown in FIG. 5, between the water pipes contacting each other,
A substantially fan-shaped region (hereinafter,
Α) is formed. In this region, the combustion gas flow becomes a swirl flow, so that the gas flow velocity is lower than that of the above-mentioned flow path of the combustion gas between the water pipes, so that the heat transfer coefficient from the combustion gas to the water pipe is low, This hinders the improvement of the thermal efficiency of the boiler as a whole.

(2) Furthermore, in order to solve the problem of (1) above, if the space between both water pipe walls is sandwiched and the flow path of the combustion gas is narrowed to increase the flow velocity, this time the pressure loss becomes large and the It is necessary to use a fan having a high air blowing capacity and a burner corresponding to this, which is an obstacle to the outer shape when manufacturing a small-sized and small-capacity boiler.

[Means for Solving the Problems]

The present invention has been made to solve the above problems, and is a multi-tube flow-through type in which a plurality of water pipes are arranged substantially in parallel in a column and combustion gas is circulated in a cross direction with respect to these water pipes. It is a boiler, and a plurality of water pipes are arranged in close contact to form a set of water pipe walls, and the water pipe walls are arranged in a staggered arrangement with respect to each other, and the distance between adjacent water pipes is small. , The pipes are arranged substantially parallel to each other so as to have a diameter not larger than the diameter of the water pipe, a combustion burner is arranged close to the center of one end of one set of the water pipe walls, and a combustion gas flow passage is provided between the water pipe walls, This is a square multi-tube once-through boiler in which a plurality of water pipes are arranged in a row from the other end of the pipe wall along the flow direction of the combustion gas.

[Action]

According to the square multi-tube once-through boiler according to the present invention, the combustion gas can be made to act on the substantially fan-shaped region between the water pipe valleys in each water pipe wall, and heat exchange with the water pipe surface in this region can be promoted. Therefore, the water stoppage area that does not contribute to heat transfer is reduced, and the heat recovery amount can be increased.

〔Example〕

FIG. 1 shows an embodiment of a square multitubular once-through boiler according to the present invention.

In the drawing, (10) and (10 ') are water pipe walls, (20) is a water pipe row,
(30) indicates a burner.

Each of the water pipe walls (10) and (10 ') is formed by arranging a plurality of water pipes (11 in this embodiment) in series in close contact with each other. These water pipe walls (10) and (10 ') are arranged on both sides of the can body so that they are substantially parallel to each other and the opposing water pipes (11) are in a staggered arrangement. Both water pipe walls
The distance between (10) and (10 ') is the distance between adjacent surfaces of the water pipes (11) that make up each water pipe wall (10) and (10') ().
However, the water pipe diameter is set to d or less (more preferably 1 / 2d or less).

The water pipe row (20) is formed by arranging the erotic fin water pipes (21) in series in the same direction as the arrangement direction of the water pipes of the water pipe walls (10) and (10 '). The array pitch of (21) is the same as the fins (2
2) They are in contact with each other.

Partitions (25), (25) are provided on both sides of such a water pipe array (20). These partition walls (25), (25) are attached in a state of substantially contacting the outer peripheral edge of the fin (22) of each of the above-mentioned erotic fin water pipes (21), and one end of each partition wall (25), (25) is , The water pipe walls (10), (10 ') described above are in close contact with the rearmost water pipe (11).

As the burner (30), it is preferable to use, for example, an all-primary air type premixing burner in which the air ratio is set to 1 or more, but this burner uses the water pipe walls (10) and (10 '). Place it between the front ends.

In the above configuration, the combustion gas from the combustion burner (30) passes between the water pipe walls (10) and (10 ') and between the partition walls (25) and (25) in a substantially straight line.

During this time, heat is transferred to the water pipes (11) of the water pipe walls (10) and (10 ') and to the erotic fin pipes (21) of the water pipe array (20).

At this time, the water pipes (11) of the water pipe walls (10) and (10 ′) are arranged in a zigzag pattern, and the water pipes (11) of the water pipe walls (10) and (10 ′) are Since the distance between adjacent water pipes is set as described above, when the combustion gas passes between the water pipe walls (10) and (10 '), as shown in FIG. Pass along meandering along (10). Therefore, each water pipe wall (10), (1
The water shut-off area α formed between the adjacent water pipes (11) and (11) of (0 ′) and making almost no contribution to heat transfer is extremely small. In other words, the surface area of the water pipe (11), which the combustion gas comes into contact with at high speed, is expanded, so that the heat transfer amount is increased. Furthermore, since the flow path of the combustion gas is formed in a meandering shape, the water pipe walls (10), (1
Even if the space of 0 ') is sandwiched, a very high pressure loss does not occur unlike the conventional boiler, and it is not necessary to change the blower.

Next, when the combustion gas passes between the water pipe walls (10) and (10 ') and flows into the partition walls (25) and (25), heat is generated in the water pipe (11) in the process so far. Therefore, the amount of heat retained is reduced, but the water pipes (21) of the water pipe array (20) between the partition walls (25) are
Compared with the water pipes (21) of the water pipe walls (10) and (10 '), since each one is an erofin water pipe having a higher heat transfer surface density, heat can be effectively recovered from the combustion gas whose temperature has dropped. .

As described above, according to the present invention, it is possible to reduce the water blocking area that does not contribute to heat transfer and improve heat recovery, without increasing the pressure loss of the boiler can body due to this.
The can body can be miniaturized.

In the above description, the number of water pipes in each of the water pipe walls (10), (10 ') and the water pipe row (20) is four, but the present invention is not limited to the above embodiment, and the number of water pipes is arbitrary. For example, as shown in FIG. 3, six water pipes each may be used. Furthermore, the number of water pipes in each water pipe wall (10), (10 ') and the water pipe array (20) may be different, and the number of water pipes in each water pipe wall (10), (10') is also the same. You don't have to.

Further, a plurality of water pipes are newly arranged between the water pipe walls (10) and (10 ′), and these water pipes and the water pipes of the water pipe walls (10) and (10 ′) are arranged.
The (11) may be staggered with respect to each other.

[Effect of device]

As described above, according to the square multi-tube through-flow boiler according to the present invention, the combustion gas is also circulated in the substantially fan-shaped portion formed between the adjacent water pipes in each water pipe wall, and the water pipe in this portion is Since the combustion gas can be brought into contact with the surface as well, the water shutoff area that does not contribute to heat transfer can be reduced and the heat recovery rate can be improved compared to the conventional one.

Further, as described above, since the water pipe walls are closely arranged so that the water pipes have a zigzag shape, the thickness of the can body can be made extremely thin. This means that a boiler with a small thickness and a small installation space will be realized,
In particular, if such a boiler is arranged along the wall surface, the amount of protrusion from the wall surface is small and the space can be effectively used.

[Brief description of drawings]

FIG. 1 is a water pipe array diagram showing an embodiment of a square multi-tube type once-through boiler according to the present invention, and FIG. 2 is a schematic plan view for explaining a heat transfer state of combustion gas on a water pipe wall, FIG. 3 is a water pipe array diagram showing another embodiment of the present invention.
FIG. 4 is a water pipe array diagram of a conventional square multi-tube type once-through boiler, which is the premise of the present invention, and FIG. 5 is for explaining a heat transfer condition from combustion gas in a water pipe wall of the boiler of FIG. 2 is a schematic plan view of FIG. (10) (10 ′) …… Water pipe wall, (11) …… Water pipe (20) …… Water pipe row, (21) …… Erophin water pipe (25) …… Differential wall, (30) …… Burner

Claims (1)

[Scope of utility model registration request] 1. A multi-tube once-through boiler of a type in which a plurality of water pipes are arranged in parallel substantially in parallel and a combustion gas is circulated in the water pipes in a crossing direction, the plurality of water pipes (11). Are arranged in close contact and a pair of water pipe walls (1
0) and (10 ') are formed, and these water pipe walls (10) and (10') are arranged in a zigzag arrangement with the water pipes (11) facing each other, and the water pipes (11) adjacent to each other have a space (). Are arranged substantially parallel to each other so that the diameter of the water pipe (11) is less than or equal to d, and the combustion burner is provided at the center of one end of one set of the water pipe walls (10) and (10 ').
The water pipe walls (10) and (10 ') are placed close to each other (30).
Between them as a flow path for the combustion gas, and a water pipe array (20) in which a plurality of water pipes (21) are arranged in a row along the flow direction of the combustion gas from the other end of the water pipe walls (10), (10 '). Square type multi-tube once-through boiler characterized by being arranged.