JP2002267266A - Atmospheric pressure boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an atmospheric pressure boiler in which natural convection is prevented from occurring on the primary side, even if a secondary circulation pump is operated during the stoppage of the primary circulation pump. SOLUTION: A channel 4 for circulating boiler water 1, contained in a storage water heater body 2 open to the atmosphere, is provided and a plate A for preventing natural convection of boiler water 1 is disposed in the circulation channel 4. The natural convection preventing plate A is provided with a flexible piece 11, resisting at least against the pressure due to natural convection of boiler water 1 and opening the central part thereof sufficiently for the delivery pressure from a heat collecting circulation pump 5, dispose in the circulation channel 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an atmospheric pressure boiler having a can body open to the atmosphere, which is a so-called non-pressure heater.

[0002]

2. Description of the Related Art Conventionally, a boiler serving as a heat source for hot water supply and air conditioning is known, but an atmospheric pressure boiler may be used in place of such a boiler.

[0003] In such an atmospheric pressure boiler, a can body is opened to the atmosphere by an overflow pipe connected to an open cylinder. Due to its structure, it does not exceed 100 ° C in principle and does not exceed atmospheric pressure. It does not require a driving license or notification of handling, and is also called a non-pressure heater.

The structure of the atmospheric boiler X will be briefly described. As shown in FIG. 7, a can body 100 is open to the atmosphere through an overflow pipe 210 connected to the open cylinder 200 described above. A combustion chamber 300 is provided on a lower side in the can body 100. The combustion chamber 300 is provided with a burner device 400 using oil or gas as fuel.

Further, the upper and lower portions of the can body 100 are communicatively connected by a circulation pipe 500, and a primary-side circulation pump 600 for heat collection is disposed on the upper side of the circulation pipe 500, while the lower side is disposed on the lower side thereof. The heat exchanger 700 is installed. The primary-side circulation pump 600 is controlled by a pump control panel 650.

[0006] A secondary water supply outgoing pipe 800 and a hot water supply return pipe 900 are communicatively connected to the heat exchanger 700, so that primary side water (hot water) that is can water W of the atmospheric pressure boiler X is connected. The heat is exchanged between the water and the secondary water for hot water supply. In addition, the water supply outgoing pipe 800 and the hot water supply return pipe 900 communicate with each other through a secondary circulation pump (not shown), and the secondary water is forcibly circulated by the secondary circulation pump.

That is, the can water W heated to an appropriate temperature such as 80 to 85 degrees by the combustion chamber is supplied to the primary side circulation pump 600.
Circulates through the circulation pipe 500 to indirectly heat the secondary water (canned water W) via the heat exchanger 700 attached to the circulation pipe 500.

In FIG. 7, 110 is a can water temperature sensor, 220 is a water level sensor, 230 is a solenoid valve for make-up water, 710 is a tap water temperature sensor, and is provided on the side surface of the can body 100 together with the pump control panel 650. It is electrically connected to the control panel 120.

Reference numeral 310 denotes a smoke tube which is connected to the combustion chamber 300 so as to guide the combustion gas and exhaust the gas to the outside of the can body 100, and a plurality of smoke tubes for effectively transferring heat to the can water W. It consists of a round pipe.

[0010]

However, the conventional atmospheric pressure boiler X having the above-mentioned structure still has the following problems.

That is, even if the canned water W, which is the primary side water, rises to a specified temperature and the primary side circulation pump 600 is stopped without a load request, the secondary side circulation pump is operated. The secondary water (canned water W) is heat-exchanged and natural convection occurs on the primary side, and the canned water circulates slowly in the circulation pipe 500, and the hot water newly flows into the heat exchanger 700. In some cases, heat was exchanged with the secondary side and the temperature of the secondary side water spontaneously increased. As described above, conventionally, there has been a problem that the control of the tapping temperature is likely to be unstable.

In particular, in a facility such as a modern public bath or a hot spring center, which is often opened in recent years instead of a conventional public bath, a usage form in which the operation of the secondary circulation pump is not stopped is generally used. Therefore, it is difficult to prevent the temperature of the secondary water from rising due to the natural convection.

Therefore, as shown in FIG. 8, a primary-side circulation pump 600 is provided at a lower position of the circulation pipe 500, and a heat exchanger 70 is provided.
It is conceivable to provide 0 at the upper position of the circulation pipe 500 and provide the check valve V between them.

However, in such a configuration, the check valve V can be effectively operated and natural convection can be prevented from being generated on the primary side. However, in the above configuration, the heated can in the can body 100 can be prevented. The can water is drawn into the circulation pipe 500 so as to oppose the convection of the water W. That is, in the can body 100, the heated hot water rises and rises to the specified temperature by convection that the low-temperature hot water goes downward, so that the can water W has a high temperature on the upper side. On the other hand, in the above configuration, the can water W is circulated from the lower side having a low temperature, which is not preferable in the basic configuration of the boiler.

An object of the present invention is to provide an atmospheric pressure boiler that can solve the above-mentioned problems.

[0016]

According to the first aspect of the present invention, there is provided a can body open to the atmosphere, a heating unit disposed in the can body, and a housing housed in the can body. And a heat collecting circulating pump and a heat exchanger provided in the middle of the circulation flow path in the atmospheric pressure boiler. A natural convection prevention plate is installed to prevent air flow.

Further, in the present invention, the natural convection preventing plate has at least a central portion which resists pressure caused by natural convection of the canned water and discharge pressure of the circulation pump for heat collection. It is characterized in that it has a flexible flexure that is flexed to open sufficiently.

According to the third aspect of the present invention, the natural convection preventing plate is provided with slits radially so as to be continuous at a central portion, and each slit forming piece formed between adjacent slits is formed as a flexible piece. It also has a feature in doing it.

Further, in the present invention according to claim 4, the heating section is provided at a lower portion in the can body, and a circulation flow path is formed by connecting and connecting the upper portion and the lower side of the can body. While installing a heat collection circulation pump in the upper part of the circulation flow path,
It is also characterized in that a heat exchanger is provided at a lower halfway position, and a natural convection prevention plate is provided near the discharge side of the heat collection circulation pump.

[0020]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a can body open to the atmosphere, a heating unit disposed in the can body, a circulation flow path for circulating can water contained in the can body, and a circulation flow path. In an atmospheric pressure boiler provided with a circulation pump for heat collection and a heat exchanger provided in the middle of the above, a natural convection prevention plate for preventing natural convection of canned water is disposed in the circulation flow path.

The heating section is provided at the lower portion of the can body, and has a combustion chamber provided at a lower portion of the can body and a burner device provided outside the can body connected to the combustion chamber.

The pipe serving as the circulation flow path is formed by connecting the upper part and the lower part of the can body in communication with each other, and a heat collection circulation pump is provided at an intermediate upper position of the circulation flow path. A heat exchanger is provided at a lower halfway position, and the can water in the can body heated by the heating unit is circulated through the circulation flow path, and exchanges heat with the secondary water through the heat exchanger.

That is, the circulation path of the secondary water for hot water supply is connected to the heat exchanger via the secondary circulation pump, so that the secondary water that has been heat-exchanged to an appropriate temperature can be supplied. It has become.

[0024] In the atmospheric pressure boiler having the above-described configuration, when the canned water as the primary side water rises to a specified temperature and the heat collecting circulating pump is stopped without a load request, the secondary side circulating pump operates. In the event, the secondary water is eventually heat-exchanged and natural convection is generated on the primary side, the can water circulates in the circulation flow path, and hot water newly flows into the heat exchanger, There is a case where the temperature of the secondary side water is naturally increased due to heat exchange with the secondary side, and the temperature control on the secondary side is likely to be unstable. It is characterized in that a natural convection preventing plate for preventing natural convection of canned water is provided therein to prevent the occurrence of natural convection.

The natural convection preventing plate is at least resistant to pressure due to natural convection of the can water, and is flexible so that the discharge pressure of the circulation pump for heat collection bends so that the central portion is sufficiently opened. It can be set as the structure provided with the bending piece which has.

For example, slits are radially provided on the natural convection preventing plate so as to be continuous at the center portion, and each slit forming piece formed between adjacent slits is a flexible piece.

Such a natural convection prevention plate is extremely simple in construction and inexpensive, but can smoothly circulate can water during normal operation of the heat collection circulating pump, and has a secondary function when the heat collection circulating pump is stopped. Even when the side circulation pump is operated, natural convection on the primary side is reliably prevented, and accurate temperature control on the secondary side can be performed.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. In this embodiment, the atmospheric pressure boiler B is used for tapping a public bath (not shown).

FIG. 1 is an overall explanatory view of an atmospheric pressure boiler B according to the present embodiment, FIG. 2 is a schematic explanatory view of the essential part, and FIG. 3 is a schematic explanatory view of a natural convection preventing plate constituting the essential part in a front view. FIG.

As shown in the figure, an atmospheric pressure boiler B is opened to the atmosphere and has a box-shaped can body 2 for storing a canister water 1, a heating section 3 disposed at a lower portion inside the can body 2, A circulation flow path 4 for circulating the water 1, a heat collection circulation pump 5 and a heat exchanger 6 provided in the middle of the circulation flow path 4, and the circulation flow path using the canned water 1 as primary water Heating unit 3 while circulating in 4
To heat exchange with the secondary water in the heat exchanger 6.

The structure of the atmospheric pressure boiler B will be described in more detail. An open cylinder 21 is connected to the ceiling 20 of the can body 2 via a connecting cylinder 21a. The can 2 is open to the atmosphere via an overflow pipe 22 connected to the container.

A water level sensor 23 is attached to the open cylinder 21 and a water supply passage 25 is connected to the open cylinder 21 via a makeup water solenoid valve 24. Then, the water level sensor 23 and the make-up water solenoid valve 24 are electrically connected to the control panel 7 attached to one end surface 2a of the can body 2, and the control panel 7 controls the water level sensor.
The opening and closing of the make-up water solenoid valve 24 is appropriately controlled based on the detection signal 23 so that the required amount of canned water 1 fills the can 2.

The ceiling portion 20 of the can 2 and the other end surface 2b are connected by a circulation pipe serving as the circulation flow path 4, and are connected to the horizontal extension portion near the rising portion from the ceiling portion 20. The circulation pump 5 for heat collection is arranged in 41, and the heat exchanger 6 is arranged below the vertical extension 42 extending vertically downward from the horizontal extension 41.

The heat-collecting circulating pump 5 is connected to a pump control panel 5a, and is connected to the control panel 7 via the pump control panel 5a.
The operation is controlled by.

The outward path 81 and the return path 82 are connected to the heat exchanger 6 as a secondary water circulation flow path 8 through a secondary circulation pump (not shown), and the secondary water is Heat exchanger 6
Circulates so as to flow into the heat exchanger 6 from a forward path 81 connected to the lower side of the heat exchanger 6 and flow out of a return path 82 connected to the upper side of the heat exchanger 6.

On the other hand, the still water 1, which is the primary side water, circulates through the circulation flow path 4 from above to below.

Then, in the heat exchanger 6, heat exchange is performed between the secondary water and the still water 1, which is the primary water,
The secondary water flows out of the return route 82, is taken in as secondary water having an appropriate temperature, and is stored in, for example, a hot water storage tank (not shown). 26 is a can water temperature sensor provided on the can body 2, 83 is a tap water temperature sensor provided on the return path 82, and is electrically connected to the control panel 7, respectively.
The output of the heating unit 3 is adjusted based on the detection signal from the controller 3.

The heating section 3 is provided in a combustion chamber 30 provided on the lower side inside the can body 2 with a burner device using fuel oil or kerosene as fuel.
31 and a flue on one side of the ceiling of the combustion chamber 30
32 are connected in series.

The flue 32 rises from the continuous base end, extends horizontally, extends outward from the upper side of the other end face 2b of the can body 2, and further extends the front end upward. Flexion and extension. 32a is the flue inside the can and 32b is the flue outside the can.

Further, a part of the flue 32a in the can is constituted by a large number of flue pipes 9 having a narrowed flow path of the combustion gas.
The high temperature combustion gas from 30 can be efficiently transferred to the can water 1 and heated.

The can water 1 heated by the heating unit 3
Is heated to a high temperature, and the whole is heated to a preset temperature by the convection in which the upper canister 1 having a lower temperature moves downward, and the predetermined temperature ( (80-85 ° C.) still water 1 circulates through the circulation flow path 4 as primary water.

Then, in the heat exchanger 6, the secondary water which has been exchanged with the secondary water and heated to a predetermined temperature is returned to the return path.
It will be hot water from 82.

The feature of the present invention in the atmospheric pressure boiler B having the above configuration is that, as shown in FIG. 2, a natural convection preventing plate A for preventing natural convection of the canned water 1 in the circulation flow path 4 is provided.
Has been arranged.

Here, the natural convection means that when the canned water 1 as the primary water rises to a specified temperature and the heat collection circulation pump 5 is stopped without a load request, a secondary circulation pump (not shown) Is operated and the secondary water circulates, the heat exchanger 6
In the inside, heat is exchanged with the secondary water, and the temperature of the can water 1 in the circulation flow path 4 is lowered because heat is deprived. Means that hot water newly flows in from the can 2. Due to such a phenomenon, the convection generated in the circulation flow path 4 is called natural convection.

When the natural convection occurs, the heat exchanger 6 further exchanges heat with the secondary side by the high-temperature water newly flowing into the circulation channel 4, and the temperature of the secondary side water naturally rises. This makes it difficult to control the temperature on the secondary side.

The present invention is to prevent such natural convection, and the natural convection preventing plate A in this embodiment is used.
Is a flexible piece 11 which is at least resistant to the pressure due to natural convection of the can water 1, and is flexible so that the discharge pressure of the heat collection circulation pump 5 is bent so as to sufficiently open the central portion. Is provided.

That is, in this embodiment, the plate body 10 of the natural convection preventing plate A is formed of a flexible synthetic resin such as rubber into a disk shape corresponding to the diameter of the pipe constituting the circulation channel 4. As shown in FIG. 3, a plurality of slits 12 continuous in the center portion are radially provided in the plate body 10, and each slit forming piece formed between the adjacent slits 12 is bent into a bending piece 11.
And

Therefore, as shown in FIGS. 2A and 3A, when the heat collection circulation pump 5 is stopped,
Even if the secondary-side circulation pump (not shown) is operated, each bending piece 11 maintains the closed state, reliably preventing natural convection on the primary side, and accurately controlling the secondary-side temperature. Can be performed.

On the other hand, as shown in FIGS. 2 (b) and 3 (b), when the heat collection circulation pump 5 is operated, each bending piece 11 is sufficiently opened by the discharge pressure of the pump 5. , The can water 1 can be circulated smoothly. The number of radially formed slits 12 and the like can be determined as appropriate.

As described above, the natural convection preventing plate A according to the present embodiment has a very simple structure, but as described above, the can water 1 smoothly flows during the normal operation of the heat collection circulation pump 5. When the circulation pump 5 for heat collection is stopped, natural convection on the primary side is reliably prevented even when the secondary circulation pump is operating, so that the temperature of the secondary side can be accurately controlled. The effect can be achieved. In addition, it can be manufactured at low cost, and does not significantly increase the manufacturing cost of the atmospheric pressure boiler B.

The position of the natural convection preventing plate A may be anywhere between the downstream side of the heat collecting circulation pump 5 and the heat exchanger 6, but the discharge pressure of the heat collecting circulation pump 5 is not limited. In order for the heat-collecting circulating pump 5 to act on the bending piece 11 without lowering, it is desirable to be near the discharge port of the circulation pump 5 for heat collection.

Here, the atmospheric pressure boiler B in this embodiment
The smoke tube 9 provided in will be further described.

As shown in FIGS. 4 to 6, the smoke tube 9 according to this embodiment is formed in a flat shape with a narrow cross-sectional width, and each side surface of the smoke tube 9 has a convex shape inside the smoke tube 9. The drawing process is performed so as to form the drawn portion 90 having a shape.

A bent flow path R of the combustion gas is formed in the smoke pipe 9 by the throttle portion 90, and a turbulent flow is generated in the combustion gas to increase the efficiency of heat transfer to the can water 1.

Further, as shown in FIG. 4, since the smoke tube 9 is of a flat and flat type, the arrangement width can be made smaller than that of the conventional round type, and the arrangement volume of the smoke tube 9 can be made smaller than that of the conventional case. It can be greatly reduced.

Therefore, it is possible to manufacture a compact atmospheric pressure boiler B in which the width of the can body 2 is reduced.

Further, when cleaning the inside of the smoke tube 9, since there is no baffle plate for promoting heat transfer, which is conventionally provided, it is possible to forcibly flush the water from one of the mouths and wash it. In order to take out the baffle plate, it is not necessary to provide a maintenance space of a predetermined size in front of the can body 2, and the restriction on the installation location of the atmospheric pressure boiler B can be greatly eased.

As shown in FIGS. 5 and 6, the throttle portion 90 can be provided alternately on the left and right smoke tube side portions 9a and 9b. With such a configuration, the combustion gas is meandered. The bent channel R can be easily formed.

Further, the throttle portion 90 can be formed in an inverted letter shape having an inclined portion 90a that can be guided in the vertical direction along the traveling direction of the combustion gas, thereby reducing the flow resistance of the combustion gas. Combustion gas can flow smoothly.

In this embodiment, the surface of the throttle portion 90 formed inside the smoke pipe 9 by the above-mentioned drawing process is curved, so that the accumulation amount of combustion products is reduced as much as possible, and The resistance can be further reduced.

[0061]

The present invention is embodied in the above-described embodiment, and has the following effects.

(1) In the present invention according to claim 1, a can body open to the atmosphere, a heating unit disposed in the can body, a circulation flow path for circulating can water housed in the can body, In an atmospheric pressure boiler provided with a heat collecting circulation pump and a heat exchanger provided in the middle of the circulation flow path, a natural convection prevention plate for preventing natural convection of canned water is disposed in the circulation flow path. Thereby, the secondary side temperature control can be reliably performed.

(2) In the present invention described in claim 2, the natural convection preventing plate resists at least the pressure due to natural convection of the can water, and the central portion of the discharge pressure of the circulation pump for heat collection has a central portion. Is provided with a flexible flexure that bends so as to open sufficiently, so that the effect (1) can be easily obtained without using a check valve or the like.

(3) According to the third aspect of the present invention, slits are radially provided on the natural convection preventing plate so as to be continuous at the center, and each slit forming piece formed between adjacent slits is bent. As a result, the effect (2) can be obtained with a simple configuration and at a low manufacturing cost.

(4) In the present invention according to claim 4, the heating section is provided at the lower portion of the can body, and the circulation flow path is formed by connecting the upper and lower sides of the can body. A heat collecting circulating pump is provided at an upper middle position of the circulation flow path, a heat exchanger is provided at a lower middle position, and a natural convection preventing plate is provided near the discharge side of the heat collecting circulating pump. Thus, the central portion is easily opened with respect to the discharge pressure of the circulation pump for heat collection to smoothly circulate the primary water, and is closed against the pressure due to the natural convection of the can water. Therefore,
It can reliably prevent natural convection on the primary side and prevent the temperature of the secondary side water from rising naturally, and can be suitably used for facilities such as public baths where the secondary side water is constantly circulated and used. it can.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an atmospheric pressure boiler according to the present embodiment.

FIG. 2 is an explanatory side view showing an attached state of a natural convection prevention plate.

FIG. 3 is an explanatory view of a natural convection preventing plate as viewed from the front.

FIG. 4 is an explanatory view of the smoke tube as viewed from the front.

FIG. 5 is an explanatory view of the smoke tube as viewed from the side.

FIG. 6 is a cross-sectional view taken along line II of FIG.

FIG. 7 is an explanatory diagram of a conventional atmospheric pressure boiler.

FIG. 8 is an explanatory diagram showing an example of a technique for preventing natural convection.

[Explanation of symbols]

 A Natural Convection Prevention Plate B Atmospheric Pressure Boiler 1 Canned Water 2 Can 4 Circulation Channel 5 Heat Collection Circulation Pump 11 Flexible Piece 12 Slit

Claims (4)

[Claims] 1. A can body open to the atmosphere, a heating unit disposed in the can body, a circulation flow path for circulating can water housed in the can body, and a collector provided in the middle of the circulation flow path. An atmospheric pressure boiler comprising a heat circulation pump and a heat exchanger, wherein a natural convection prevention plate for preventing natural convection of canned water is provided in the circulation flow path. 2. The natural convection preventing plate may be configured to resist at least the pressure due to natural convection of the can water and to bend so as to sufficiently open the central portion against the discharge pressure of the circulation pump for heat collection. 2. The atmospheric pressure boiler according to claim 1, further comprising a flexible piece having flexibility. 3. A natural convection preventing plate, wherein slits are radially provided so as to be continuous at a central portion, and each slit forming piece formed between adjacent slits is a flexible piece. 2. The atmospheric pressure boiler according to 2. 4. A heating unit is provided in a lower portion of the can body, and a circulation flow path is formed by connecting an upper portion and a lower side portion of the can body so as to communicate with each other. The heat circulating pump is provided, a heat exchanger is provided at a lower halfway position, and a natural convection preventing plate is provided near the discharge side of the heat collecting circulating pump. An atmospheric pressure boiler according to any one of the preceding claims.