JPS58136933A - Regenerator for combustion gas of gas boiler - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for imparting most of the heat from the boiler to the water or steam stream while the water passes vertically from below to above through the heat exchanger, i.e. the main heat exchanger. This invention relates to a regeneration device that recycles residual heat from stored combustion gas.

It is known that the upward flow of combustion gases from such a main heat exchanger, which is generally considered to be at a relatively high temperature of 100' to 200°C, contains boiled water in the form of steam. There is.

When the combustion gases are cooled below the dew point of about 60° C., where water begins to condense, heat, or latent heat of vaporization, is generated that is used to evaporate the water.

It is well known to recycle this heat by passing the cooled combustion gas through an auxiliary heat exchanger.

However, the auxiliary heat exchangers of this type proposed so far have a number of drawbacks. In particular, since the combustion gases passing through this type of heat exchanger cause a pressure loss, it is recommended, for example, to use mechanical extraction devices or to remove the combustion gases after they have passed through this heat exchanger. Special processes such as heating are required.

It is an object of the invention to overcome the above-mentioned disadvantages and, in a preferred embodiment, to simplify the construction and maintenance of the playback device and to eliminate the space requirements.

Therefore, according to the present invention, the auxiliary heat exchange device is configured to be relatively flat and thin so as to provide a low resistance to the combustion gas passing in the direction of its thickness, that is, in a direction perpendicular to its average center plane. and is installed so that the average center plane is substantially vertical, and the combustion gas to be cooled passes through the auxiliary heat exchanger in the thickness direction. be.

Preferred embodiments of the invention may include the following features.

The configuration of the auxiliary heat exchanger is already known as the configuration of the main heat exchanger, but it includes jigged pipes that support parallel plates that extend in parallel straight lines and form fins.◎ Auxiliary heat exchange The configuration of the vessel may be the same as that of the main heat exchanger.

Vertically above, a box is provided for horizontally guiding the combustion gases leaving the main heat exchanger for collection and introduction into the auxiliary heat exchanger, said box being substantially separated by at least one intermediate partition wall. Divided into parallel passages, the combustion gases to be cooled are distributed over the inlet face of the auxiliary heat exchanger.

The auxiliary heat exchanger is installed above the main heat exchanger, and the outlet of the main heat exchanger is connected to the inlet of the auxiliary heat exchanger, and the outlet of the auxiliary heat exchanger is discharged from the outlet of the auxiliary heat exchanger. It may be provided that the upstream box and the downstream box respectively guiding the combustion gases into the openings occupy a large part of the horizontal space of the air conditioner in which they are installed.

The horizontal central plane of the auxiliary heat exchanger is vertical and 111
1t! It may also be made to pass through the center of the main heat exchanger.

An auxiliary downstream box may be configured to guide combustion gas toward a passage located directly above the auxiliary heat exchanger.

A screen in which the proportion of openings per unit area increases as it goes downwards may be located in the combustion gas passage at the outlet of the auxiliary heat exchanger.

The invention will now be described in detail with reference to the illustrated embodiments.

A gas boiler, which is known per se, has a combustion chamber 1, the upper part of which is covered by a heat exchanger 2 (hereinafter referred to as "main heat exchanger").

This heat exchanger has a relatively flat and thin rectangular lattice shape as a whole, through which heated water flows and provides low resistance to the upward vertical gas flow of combustion gas from the boiler. .

A fin structure or pie f having a plurality of extensions supported by parallel vertical plates 4 connected by semicircular bends and forming fins, through which the heated water passes.
3 forms a heat exchanger.

The combustion gas flowing vertically from the top of this heat exchange rI2 is
In the present invention f14, the residual heat possessed by the combustion gases According to the present invention, the second or auxiliary heat exchanger 5 is preheated in a suitable sealed circuit along a passage parallel to its mean central plane. It has a relatively flat and thin lattice-like shape through which water passes, and is configured to provide low resistance to the combustion gas flowing perpendicularly to the average central plane.

In other words, only a small pressure loss occurs in the combustion gas flow passing in the direction perpendicular to the mean center plane of the heat exchanger, ie in the direction of the shortest thickness of the heat exchanger.

In this auxiliary heat exchanger, as in the main heat exchanger described above, the two fluids exchanging heat are "crossed" or perpendicular to each other at all points, and the web formed by the water tubes is The single paths of are orthogonal. The combustion gases may be passed parallel to this web and perpendicular to the water pipes, or the fluid directions may be parallel to each other and quite opposite, as in a counter heat exchanger.

Although not always necessary, it is effective to form an auxiliary heat exchanger in the same way as the main heat exchanger, so that in %, the preheated water passes through its parallel straight line g! It is effective to use a jig-shaped pipe in which the elements are connected by semicircular curved parts, made of a heat-conducting metal, and supported by parallel plates 7 forming fins.

The two main heat exchangers 2 and the auxiliary exchange@5 may be one and the same.

The mean central plane of the auxiliary heat exchanger 5 is inclined with respect to the vertical plane within an angle of at most 45°, preferably 0° as in the illustrated embodiment.

In a first embodiment shown in FIG. 1, the auxiliary heat exchanger is horizontally spaced apart from the main heat exchanger 2, and its lower end is rounded at the same height as the main heat exchanger.

Furthermore, the first box 8 receives the combustion gases (F) directed vertically upwards from the main heat exchanger 2 and guides the combustion gases horizontally or perpendicularly to the mean center plane of the auxiliary heat exchanger 5 .

The second box 9 receives the combustion from the auxiliary heat exchanger and guides the combustion gases to an upwardly opening opening 10.

The lower upstream end of the first box 8 is beveled for easy attachment to the upper part of the combustion chamber 1, for example by fixing and bolting, and the upper downstream end of the second box 9 is fitted with a conventional backflow prevention device. In other words, it can be easily attached to the exhaust chimney via the damper.

The mesh 9 is known per se as a drain chamber for collecting residues formed in the chimney. - The first box is fitted with a partition wall 11 so that the inlet surface of the auxiliary heat exchanger 50 is uniformly aerated by IIC% by the combustion gases passing through it.
It is divided into 111I contacting passages.

Preferably, these partition walls have lower ends vertically upstream 511
1. Also, the upper layer is horizontal or almost horizontal downstream 11. It is formed from a flat slanted metal sheet.

The number of passages formed in this way is 3 as shown in the figure.
f! 11! It can be increased or decreased depending on the situation.

A trough 12 is provided on the lower side of the auxiliary heat exchanger 5 for cooling the passing combustion gas and collecting condensate by its own weight. In the embodiment, the heat exchanger is vertically oriented and the valley 12 is relatively narrow.

In the second embodiment shown in FIG. 2, similar members to those described above are designated by the same reference numbers.

In the second embodiment, instead of placing the auxiliary heat exchanger 5 horizontally apart from the main heat exchanger 2 as in the first embodiment, the auxiliary heat exchanger 5 is placed directly above the main heat exchanger. It is a provision.

If the auxiliary heat exchanger 5 is installed vertically, its vertical mean central plane (P) preferably passes through the center of the device, ie, the center of the main heat exchanger as shown.

The condensate collected in this auxiliary heat exchanger 2 is transferred to the main heat exchanger 2.
The burner 110 of the boiler also falls on top due to gravity.
To prevent it from falling onto the flame 16, a trough 18 is provided below the auxiliary heat exchanger to collect this condensate, the bottom of which is connected to a discharge pipe 19 below.

This pipe 19 passes around the combustion chamber 1 and conveys the condensate that is received in a drain container provided outside the boiler and, more precisely, via a siphon that seals the inside and outside of the boiler. It is arranged as follows.

The valleys 18 and pipes 19 are made of a material such as aluminum or aluminum alloy, which is resistant to the oxidizing effects of condensate and heat.

The two boxes 8 and 9 are so shaped that they occupy at least a large part of the horizontal space occupied by the point 2 - or more precisely the combustion chamber.

This reduction in volume, made possible by providing an auxiliary heat exchanger above the main heat exchanger, has a great effect.

The combustion gas passage in box 8 of @1 is stretched out.
It is in the shape of 81 characters. The combustion gas (F) from the main heat exchanger 2 below the valley 18 flows peacefully along the lower surface of the valley in a first direction (left II in the figure), and in the opposite direction to the first direction, that is, in the figure It then moves diagonally (skirting) before being guided horizontally to the right towards the auxiliary heat exchanger and rising.

To this end, the box 8 has a horizontal or nearly horizontal metal sheet 20, which sheet forms a baffle;
The portion directly above the main heat exchanger 2 and the outlet portion of the auxiliary heat exchanger 5 do not communicate directly perpendicularly.

In order to ensure that the inlet face of the auxiliary heat exchanger 5 is uniformly scavenged by the passing combustion gas IF), the box 8 is preferably divided by a partition wall 23 into two contiguous passages.

This partition wall 23 is preferably continuously formed from a flat, newly curved metal sheet configured as follows.

Vertical 5231 is a false main heat exchange between the main heat exchanger 2 and the bottom surface of the valley 1B! 2 along the mean central plane (P). Further, the partition wall 23 has a horizontal or inclined portion 23□, a vertical portion 233, and a horizontal or inclined portion 234 extending to the center of the height of the inlet surface of the auxiliary heat exchanger 50.

The passage of the combustion gas (F) in the second box 9 is also elongated and has a substantially 1S1 shape, and the combustion gas coming out horizontally from the auxiliary heat exchanger 5 is guided upward, and then upward from the opening 10. About the time it is discharged, it flows horizontally in the center of the device, ie in the opposite direction to the direction in which it exits the auxiliary heat exchanger.

In order to increase the efficiency of the device, it is also effective to adjust the change in the flow rate of combustion gas from the auxiliary heat exchanger 5 by varying this discharge position.

In fact, due to the design of the combustion gas passage in box 8, the combustion gas naturally tends to concentrate at the highest point of heat exchanger 5;
Therefore, the highest point of the heat exchanger 5 greatly affects heat exchange.

To eliminate this drawback, the combustion gases are discharged from the lowest point of the heat exchanger 5 by means of a vertical or nearly vertical plate 24 having openings 25 whose degree of opening increases as one goes downwards. This can be easily done by placing it near the outlet.

This arrangement can also be used if there is no limit to the pressure loss problem.
In particular, if a mechanical venting device is supplied to the duct exhausting the combustion gases downstream of the plate 24 with openings,
effective.

In the absence of mechanical ventilation, it is better not to use this arrangement, since only a very small pressure drop will occur between the two heat exchangers 2.
The above-mentioned arrangement is particularly effective and possible when caused by combustion gases passing through and 5.

The operation of the regenerator or recoverer described above is as follows.

As shown in FIG. 3, the boiler generally includes a central heating closed circuit having a connecting pipe 13, a circulation pump 14, a heating member 15 such as a heating floor or radiator, and the above-mentioned heat exchanger. Heat flowing water. It is something.

The order in which the heated circulating water flows through these heat exchangers is first the auxiliary heat exchanger and then the main heat exchanger.

This water has relatively low humidity, i.e. between 20°C and 40°C;
On the other hand, the combustion gas (
The temperature of F) is generally quite high, 100°C or higher.

Due to the contact of the still high temperature combustion gas with the metal surface of the heat exchanger 5 at a relatively low temperature, the combustion gas is cooled to the dew point, and the water vapor contained in the combustion gas that has contacted this metal surface is condensed. , the latent heat of condensation of the steam is generated in this plane.

The heat regeneration device described above has many advantages, including:

Due to the very small pressure loss due to the combustion gases when passing through the auxiliary heat exchanger, it makes no sense to provide special extraction devices such as fans to remove this combustion gases, and natural ventilation is sufficient in this case. It is.

In the embodiment shown in FIG. 2, the regenerator is mounted above the boiler and is constructed so that it occupies the horizontal space of the boiler.

The regenerator can be installed very easily in a conventional boiler without modifying the boiler.

This gives rise to the advantage that the regenerator can be purchased as an "accessory" as an optional equipment for the boiler.

If the auxiliary heat exchanger has the same construction as the main heat exchanger, manufacturing and maintenance problems are considerably simplified.

As mentioned above, there are no limitations on the application of the present invention.
Many modifications are possible, and are not particularly limited to the application as shown in the examples.

the auxiliary heat exchanger has the same units as the main heat exchanger, these two units can be arranged laterally, vertically on top of the -10,000 units, or even parallel to each other; The combustion gases to be cooled pass through these units one by one.

The auxiliary heat exchanger is formed according to the same principle as the main heat exchanger, but the heat exchange surface can also be increased.

The auxiliary heat exchanger is flat and thin so as to provide a low resistance to the combustion gas flow perpendicular to its mean center plane, but the shape is not limited thereto.

The mean central plane of the auxiliary heat exchanger may be inclined with respect to the vertical direction.

As described above, the present invention is not limited to the illustrated embodiment.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of a heat regeneration device according to the invention, FIG.
The figure shows a vertical sectional view of another embodiment according to the invention and a sixth embodiment.
The figure is a schematic explanatory diagram of the present invention. DESCRIPTION OF SYMBOLS 1... Combustion chamber, 2... Main heat exchanger, 3... Pipe, 4... Fin plate, 5... Auxiliary heat exchanger, 6
...Pipe, T...Fin plate, 8...#!
1 box, 9...second box, 10...opening, 11...partition wall, 23...partition wall, 24...
Plate, 25... Opening, Representative Asamura Kogai 4 people

Claims (1)

[Claims] (1) An auxiliary heat exchanger in which the combustion gas passes through the main heat exchanger (2) in order to regenerate residual heat contained in the combustion gas in the spoiler after vertically passing through the main heat exchanger (2). In the regenerator equipped with a heat exchanger (5), the auxiliary heat exchanger (5) is configured to provide a low resistance to the combustion gas passing in the thickness direction of the auxiliary heat exchanger (5), that is, in a direction perpendicular to its average center plane. It is configured to be relatively flat and thin, and is installed so that the average center plane is substantially vertical, so that the combustion gas to be cooled passes through the auxiliary heat exchanger in the thickness direction. Characteristic playback device. (2. In the regenerator according to claim 1, the auxiliary heat exchange gII(5) extends in a parallel straight line,
A reproducing device characterized in that it is composed of a pipe (6) K supporting a parallel plate (7) forming a tween. (314f-The regeneration device according to claim 1, characterized in that the configuration of the auxiliary heat exchanger (5) is the same as the configuration of the main heat exchanger. (4) Patent In the regenerator according to claim 1, the combustion gas emitted from the main heat exchanger (2) vertically upward is recovered and guided horizontally to be introduced into the auxiliary heat exchanger (5). Box (8) is supplied to
Said box (8) is connected to at least one intermediate partition wall (1
1,23) A regeneration device, characterized in that it is divided into substantially parallel passages, such that the combustion gas to be cooled is distributed over the entire inlet face of the auxiliary heat exchanger (5). (5) In the regenerator according to claim 1 or 4, the auxiliary heat exchanger (5) is provided above the main heat exchanger (2), and the auxiliary heat exchanger (5) is provided above the main heat exchanger (2). (2)
an upstream box (8) and a downstream box (9) that guide combustion gas from the outlet of the auxiliary heat exchanger (5) to the inlet of the auxiliary heat exchanger (5) and from the outlet of the auxiliary heat exchanger (5) to the discharge opening (10), respectively. ) is characterized in that it occupies most of the horizontal space of the boiler in which it is installed. (6) In the reproduction device according to claim 5,
A regenerator characterized in that the average central plane (P) of the auxiliary heat exchanger (5) is vertical and passes through the central part of the main heat exchanger (2). (7) In the regenerator according to claim 5 or 6, the downstream box (9) guides combustion gas toward a passage located directly above the auxiliary heat exchanger (5). A playback device characterized in that it is configured as follows. (8) In the reproduction device according to claim 5,
A regeneration device characterized in that a plate (24) in which the ratio of openings (25) per unit area increases as it goes downward is located in the combustion gas passage at the outlet of the auxiliary heat exchanger.