JPH024363Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchange device, and more particularly to a heat exchange device that heats a fluid to be heated by indirect heat exchange with combustion exhaust gas of a burner.

Conventionally, a heat exchanger tube through which a heated fluid flows is arranged in the middle of a combustion exhaust gas flow, and heat exchange between the combustion exhaust gas and the heated fluid is achieved through the tube wall of the heat exchanger tube. However, since the film heat transfer coefficient between the pipe wall and the combustion exhaust gas is relatively low, it cannot be said that the heat exchange efficiency is excellent. Furthermore, there was a risk that the heat exchanger tubes would be locally overheated and burnt out.

Another prior art is, for example, an exhaust boiler disclosed in Japanese Patent Application Laid-Open No. 53-51550. In this prior art, a bottom plate is provided on the upper part of the outer shell, a tank is formed on the bottom plate, and a large number of small holes are bored in this bottom plate.
A tank formed on the bottom plate is supplied with water to be heated. Water falls through the small holes. In this outer shell, an airtight combustion chamber containing a burner is provided below the bottom plate, and an exhaust pipe that opens above the liquid level is provided above the bottom plate. , an exhaust port is formed below the bottom plate near the bottom plate. The water that is stored and bathes the combustion chamber is circulated by a pump to a tank on the bottom plate.

In such prior art, water simply falls through small holes drilled in the bottom plate and is heated by contact with combustion gas from the exhaust port, so it is desirable to further improve heat exchange efficiency. .

In addition, in this prior art, water simply falls downward from small holes formed in the bottom plate, so the water droplets are large in size or in a continuous flow, and therefore do not interact with the combustion gas. It is desired that the contact area is small, which also further improves the heat exchange efficiency.

Furthermore, in this prior art, evaporation occurs from the water surface of the water that falls through the small hole in the bottom plate, is heated, and is stored in the outer shell, so that the corresponding amount of heat is carried away. Therefore, it is highly desirable to improve the heat exchange efficiency by this.

An object of the present invention is to provide a heat exchange device that improves heat exchange efficiency as much as possible and eliminates the risk of burnout.

In the present invention, a flat lid is provided at the lower part of the sealed casing with a flow gap formed between the peripheral edge and the inner surface of the casing, and a heating tank in which hot water is stored is formed below the lid. A heat exchanger having heat transfer tubes through which a fluid to be heated flows is disposed in the heating tank, and in the casing above the lid, heat exchangers are disposed at intervals in the lateral direction and arranged alternately along the lateral direction. A plurality of heat exchange chambers are formed by a plurality of partition plates that form a flow path between the casing ceiling wall and the lid, and the upper part of each heat exchange chamber is connected to the heat exchanger via a circulation pipe equipped with a pump. A header connected to the heating tank and provided with a plurality of spray nozzles is commonly provided, and the spray nozzles are formed on the upper, lower, and left and right sides of the header, and the fluid to be heated is sprayed from the spray nozzle, A combustor that forms a combustion chamber and has an air outlet opening diagonally downward at the top thereof is provided so as to protrude into the heat exchange chamber at one lateral end, and an all-primary air burner is installed in the combustion chamber. The heat exchange device is characterized in that a heat exchange chamber is inserted therein, and an exhaust pipe is connected to the heat exchange chamber at the other end in the lateral direction.

In a preferred embodiment, an opening that communicates the combustion chamber with the atmosphere is formed at a lower portion of a portion of the combustor that protrudes from the casing.

In a further preferred embodiment, a water filling pipe extending above the hot water surface is connected to the lower part of the heating tank, and an overflow pipe is connected to a position in the middle of the water filling pipe corresponding to the hot water surface of the heating tank. It is characterized by

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall vertical sectional view of an embodiment of the present invention. In this heat exchange device 1, combustion exhaust gas generated in the combustion chamber 2 sequentially passes through the first heat exchange chamber 3, the second heat exchange chamber 4, and the third heat exchange chamber 5 and is discharged. In each heat exchange chamber 3, 4, 5, fine water droplets are sprayed by a spray nozzle 6,
As the water droplets descend, they are heated by contact with the combustion exhaust gas and introduced into the heating tank 7. This heating tank 7
Inside the heat exchanger 8, a fluid to be heated, such as water, flowing through the heat exchanger 8 is indirectly heated, thereby producing hot water for hot water supply or space heating.

The closed casing 9 of the heat exchanger 1 is shaped like a box that is long in the horizontal direction, and a lid 1 is provided at the bottom inside the casing 9.
0 is fixedly provided. There is a flow gap 11 between the peripheral edge of the lid 10 and the inner surface of the casing 9.
is formed. Also, the lid 1 inside the casing 9
A heating tank 7 is formed below 0, and hot water is stored in the heating tank 7. In addition, a heat transfer tube 8 is provided in the heating tank 7.
A heat exchanger 8 having a heat exchanger 8 is disposed, and an inlet of the heat exchanger 8 is connected to a water supply source (not shown), and an outlet is connected to a water heater, a space heater, or the like.

In the casing 9, above the lid 10, a plurality of partition plates 12 and 13 (two shown) are provided at intervals in the lateral direction. These partition plates 1
2 and 13, a plurality (three shown) of first, second, and third heat exchange chambers 3, 4, and 5 are formed above the lid 10 in the casing 9. Moreover,
The partition plate 12 is installed upright on the lid 10, and the partition plate 1
A flow path 14 is formed between the upper end of the casing 2 and the casing ceiling wall 9a. Further, the partition plate 13 is suspended from the ceiling wall 9a, and a flow path 15 is formed between the lower end of the partition plate 13 and the lid 10. In this way, the first heat exchange chamber 3 and the second heat exchange chamber 4 communicate with each other via the upper flow path 14, and the second heat exchange chamber 4 and the third heat exchange chamber 5 communicate with each other via the lower flow path 15. communicate with each other via. Therefore, the combustion exhaust gas is transferred from the first heat exchange chamber 3 to the second heat exchange chamber 4 to
It flows up and down in a zigzag manner to the third heat exchange chamber 5.

In the upper part of the casing 9, each heat exchange chamber 3, 4, 5 is provided with a common header 16, in which a plurality of spray nozzles 6 are installed.
As clearly shown in the figure, they are formed on the top, bottom, and left and right sides of the header 16. One end of a circulation pipe 18 equipped with a pump 17 is connected to the header 16 . The other end of the circulation pipe 18 is connected to the heating tank 7 . Therefore, by driving the pump 17, hot water in the heating tank 7 is supplied to the header 16,
The hot water is sprayed into each heat exchange chamber 3 through a spray nozzle 6.
It is sprayed on 4 and 5.

FIG. 2 is a sectional view taken along the section line - in FIG. 1. A combustor 19 forming a combustion chamber 2 is provided in the first heat exchange chamber 3 . This combustor 19 is
It consists of a plunge part 20 that plunges into the first heat exchange chamber 3 and a protrusion part 21 that protrudes from the casing 9 to the outside. The plunge part 20 has a cross section approximately U with an open upper part.
The upper part of the letter-shaped box body 22 is covered with a cover plate 23 and a plurality of inclined plates 24. Each inclined plate 2
4 are provided on both sides of the box body 22 so as to be inclined downwardly toward the outside and are spaced apart from each other vertically, and the cover plates 23 are provided to cover the uppermost portions of the inclined plates 24 on both sides. In this way, air outlets 25 that open obliquely downward are formed between the cover plate 23 and the inclined plates 24, between the upper and lower inclined plates 24, and between the box body 22 and the inclined plates 24. According to such a configuration, the combustion exhaust gas is allowed to flow from the combustion chamber 2 to the first heat exchange chamber 3, but water droplets from the spray nozzle 6 are prevented from entering the combustion chamber 2. Ru.

The protrusion 21 has a sealed box shape, and an opening 26 for communicating the combustion chamber 2 with the atmosphere is formed in the lower part of the protrusion 21 .

A primary air burner 27 is inserted into the combustion chamber 2 of the combustor 19 . This all-primary air burner 27 is constructed by having a plurality of flame holes 28 bored in the wall of a cylinder made of a heat-resistant material. The all-primary air burner 27 is supplied with a mixed gas of combustion gas and combustion air, as indicated by the dashed arrow. This mixed gas is blown out of each flame hole 28 and combusted, thereby forming a short flame in each flame hole 28. An igniter 29 and a flame rod 30 are inserted into the combustor 19.

A water injection pipe 31 extending above the hot water surface l in the heating tank 7 is connected to the lower part of the heating tank 7 . Further, an overflow pipe 32 is connected to a position in the middle of the water injection pipe 31 corresponding to the hot water surface l.

Note that an exhaust pipe 33 is connected to the third heat exchange chamber 5, and this exhaust pipe 33 is connected to an induced fan (not shown) or is opened to the atmosphere.

In the heat exchange device 1 configured in this way,
To heat the fluid to be heated, the primary air burner 27 is ignited, and the pump 17 is driven to spray water droplets from the spray nozzle 66. The combustion exhaust gas generated in the combustion chamber 2 is transferred to the first heat exchange chamber 3.
It sequentially flows through → second heat exchange chamber 4 → third heat exchange chamber 5, but during that time it comes into direct contact with water droplets that have become mist. Therefore, the water droplets are heated by direct contact, but the surface area of the water droplets is large because they are in the form of a mist. Therefore, the combustion exhaust gas and the water droplets exchange heat efficiently. Moreover, since the combustion exhaust gas flows in a zigzag manner up and down through the partition plates 12 and 13, the contact time with water droplets is increased, which also improves the heat exchange efficiency. The heated water droplets descend in each heat exchange chamber 3, 4, 5 and are guided into the heating tank 7 through the inflow gap 11, and in this way, the heating tank 7
The hot water inside is heated.

By passing the fluid to be heated through the heat exchanger 8 in the heating tank 7, the fluid to be heated in the heat transfer tube 8a is heated by indirectly exchanging heat with the hot water in the heating tank 7. At this time, since the film heat transfer coefficient between the tube wall of the heat transfer tube 8a and the hot water is higher than that between heat transfer with gas, the fluid to be heated is efficiently heated. Also, heat exchanger tube 8a
Since the heat exchanger tubes 8a do not come into contact with high-temperature combustion exhaust gas, there is no risk of the heat exchanger tubes 8a burning out.

The diameter and amount of water droplets sprayed from the spray nozzle 6 must be selected so that they do not evaporate on contact with combustion exhaust gas. Furthermore, by keeping the outer surface of the plunger 20 of the combustor 19 constantly wet with water droplets, it is possible to use a relatively low-grade material for the plunger 20; The same applies to the partition plates 12 and 13 and the casing 9.

Since the hot water stored in the heating tank 7 is covered by the lid 10, natural evaporation during extinguishing the fire is prevented as much as possible. Furthermore, when extinguishing a fire, it is expected that each of the heat exchange chambers 3, 4, and 5 will be filled with steam. However, the opening 2 in the combustor 19
6, moisture vapor is prevented from entering the combustion chamber 2 by drawing atmospheric air through the opening 26 by forced induction from the exhaust pipe 33 or by natural ventilation. Therefore, water vapor is prevented from condensing on the outer surface of the all-primary air burner 27, and therefore the all-primary air burner 27
Re-ignition becomes easy.

Water is injected into the heating tank 7 from the water injection pipe 31 in accordance with the drop in the hot water level l, but a liquid level gauge (not shown) is provided to detect the hot water level l, and the hot water level l drops below a set level. It may be configured to automatically inject water when Note that when moisture in the combustion exhaust gas condenses and the amount of hot water in the heating tank 7 increases, it overflows from the overflow pipe 32, so the hot water level l is kept constant.

Note that it is possible to increase the contact time between the combustion exhaust gas and water droplets by making the casing 9 longer in the lateral direction and omitting the partition plates 12 and 13, but since the water droplets fall immediately, heat exchange is not possible. It is less efficient and therefore not a good idea.

As described above, according to the present invention, a heat exchange device with improved heat exchange efficiency and no risk of burnout can be obtained. Moreover, since the top of the heating tank is covered with a lid, evaporation during extinguishing is suppressed to the utmost, and water consumption is reduced.

In particular, in the present invention, a plurality of partition plates 12 and 13 are provided in the casing 9, and the partition plates 12,
13 are arranged at intervals in the lateral direction (horizontal direction in FIG. 1), and form flow passages between the casing ceiling wall and the lid alternately along the lateral direction, thus forming a plurality of heat exchange chambers. is forming. The path of the combustion gases from the all-primary air burner is therefore longer and therefore better in contact with the fluid to be heated. This improves heat exchange efficiency. This burner is provided so as to protrude into a heat exchange chamber at one lateral end (the right end in FIG. 1) of the casing 9, and a heat exchange chamber at the other lateral end (the left end in FIG. 1). An exhaust pipe 33 is connected to the exhaust pipe 33, and the combustion gas passes through a plurality of heat exchange chambers partitioned by partition plates 12 and 13 in a zigzag pattern up and down.

In addition, in the present invention, the spray nozzle is placed on the header,
The heating fluid is sprayed from the spray nozzle at the bottom and on the left and right sides, so that the heating fluid is supplied from above to the heat exchange chamber in small droplets. This increases the contact area between the combustion gas and the fluid to be heated, and thereby also improves the heat exchange efficiency.

Furthermore, in the present invention, a lid is provided on the heating tank in which hot water is stored. Therefore, evaporation of the stored hot water is suppressed as much as possible. This can suppress heat being carried away from the hot water. This also makes it possible to improve the heat exchange efficiency. In this way, the present invention can significantly improve heat exchange efficiency compared to the prior art.

[Brief explanation of the drawing]

FIG. 1 is an overall vertical cross-sectional view of an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the section line - in FIG. 1. 1... Heat exchange device, 2... Combustion chamber, 3... First
Heat exchange chamber, 4... Second heat exchange chamber, 5... Third heat exchange chamber, 6... Spray nozzle, 7... Heating tank, 8...
Heat exchanger, 8a... Heat exchanger tube, 9... Casing,
10... Lid, 11... Flowing gap, 12, 13...
Partition plate, 14, 15... Distribution path, 16... Header, 17... Pump, 18... Circulation pipe, 19...
Combustor, 20...Plunging part, 21...Protruding part, 25
...Blowout port, 26...Opening, 27...All primary air burner, 31...Water injection pipe, 32...Overflow pipe, 33...Exhaust pipe.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A flat lid is provided at the bottom of the sealed casing with a flow gap formed between the peripheral edge and the inner surface of the casing, and hot water is stored below the lid. A heat exchanger having a heat exchanger tube through which a fluid to be heated flows is arranged in the heating tank, and a heat exchanger having heat transfer tubes through which a fluid to be heated flows is arranged in the casing above the lid. By a plurality of partition plates that alternately form a flow path between the casing ceiling wall and the lid along the lateral direction,
A plurality of heat exchange chambers are formed, and a header connected to the heating tank via a circulation pipe equipped with a pump and equipped with a plurality of spray nozzles is commonly provided at the upper part of each heat exchange chamber. are formed on the top, bottom, and left and right sides of the
The fluid to be heated is sprayed from the spray nozzle to form a combustion chamber, and a combustor having an outlet opening diagonally downward at the upper part is provided so as to protrude into the heat exchange chamber at one lateral end; A heat exchange device characterized in that an all-primary air burner is inserted into the combustion chamber, and an exhaust pipe is connected to the heat exchange chamber at the other lateral end. (2) The heat exchange device according to claim 1, wherein an opening for communicating the combustion chamber with the atmosphere is formed in the lower part of the portion protruding from the casing of the combustor. (3) A water injection pipe extending above the hot water surface is connected to the lower part of the heating tank, and an overflow pipe is connected to a position in the middle of the water injection pipe corresponding to the hot water surface of the heating tank. A heat exchange device according to claim 1 or 2 of the utility model registration claim.