JP3292105B2 - Hot water boiler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water boiler for heating using oil, gas or the like as a fuel, and more particularly to a structure of a heat exchanger.

[0002]

2. Description of the Related Art FIG. 4 is a cross-sectional view showing a conventional hot water boiler disclosed in Japanese Patent Application Laid-Open No. 1-134126, in which reference numeral 20 denotes a burner for combustion, and reference numeral 21 denotes an upper portion of the burner 20. The combustion chamber 22 is a preheating water pipe wound around the outer peripheral surface of the combustion chamber 21, 23 is a plurality of heat receiving fins, 24 is in communication with the preheating water pipe 22,
A heat exchange pipe portion tightly fixed to the heat receiving fins 23; 25, a hot water heat exchanger composed of the heat receiving fins 23 and the heat exchange pipe portion 24; 26, a top plate; 27, an exhaust pipe provided on the top plate 26; Is a hot water return port, and 29 is a hot water outlet.

Next, the operation will be described. By the combustion gas generated by the combustion burner 20, the low-temperature water entering from the hot water return port 28 is first preheated by the preheating water pipe 22 by heat conduction from the wall of the combustion chamber 21, and then the heat exchange pipe section 2
4, the heat received by the heat receiving fins 23 is thermally conducted to the heat exchange pipe section 24, and the preheated water passing through the pipe is heated to a high temperature and supplied from the hot water outlet 29 to the heating location. The combustion gas after the heat exchange is discharged to the outside through an exhaust pipe 27 provided on the top plate 26.

[0004]

Since the heat exchanger of the conventional hot water heating apparatus is constructed as described above, the preheating water pipe 22 and the heat receiving fins 23 extend from the wall of the combustion chamber 21.
From the heat exchange pipe portion 24 to the heat exchange action by heat conduction in the plate thickness plane, the material of the wall constituting the combustion chamber 21 is an expensive copper plate with very good heat conduction, a preheating water pipe The copper pipe 22 is used for the heat exchange pipe 22 and the heat exchange pipe section 24. In addition, in order to reduce the thermal contact resistance, the wall of the combustion chamber 21 is brazed to prevent corrosion caused by dew condensation of the combustion gas. It is necessary to apply a lead hot-dip plating process, and there are problems that the manufacturing process is extremely complicated and the cost is increased.

The present invention has been made in order to solve the above-mentioned problems, and the manufacturing process is simple and the productivity is good. Further, the material of the heat exchanger can be made of inexpensive stainless steel or the like. The objective is to obtain an economical and compact hot water boiler that can achieve high quality and high performance.

[0006]

According to the present invention, there is provided a hot water boiler comprising: a combustion burner; a first heat exchanger having a cylindrical shape provided above the combustion burner; 1
Around the outer circumference of the heat exchanger with a small gap
And forming a combustion chamber below the first heat exchanger.
A first heat exchanger and a second heat exchanger, one of which has a hot water return port and a communication port, and the other has a hot water outlet port. A first heat exchanger and a second heat exchanger are connected in series by providing a port and connecting both communication ports with a connecting pipe, and the first heat exchanger and the second heat exchanger facing the exhaust gas path are connected to each other. In which a plurality of concave ribs are formed on at least one peripheral wall of the heat exchanger.

Further, the concave rib is formed on both the outer peripheral wall of the first heat exchanger and the inner peripheral wall of the second heat exchanger.

The first heat exchanger is provided with a hot water return port and a communication port, and the second heat exchanger is provided with a hot water outflow port and a communication port at a lower part thereof. The flow of the warm water passing through the warm water return port is substantially countercurrent to the flow of the warm water.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, a first embodiment of a hot water boiler of the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view showing a first embodiment of a hot water boiler according to the present invention, and FIG. 2 is an enlarged sectional view of a main part thereof. 1 and 2, reference numeral 1 denotes a combustion burner, 2 denotes a first heat exchanger provided in an upper portion of the combustion burner 1, and is a heavenly cylindrical first heat exchanger formed of stainless steel or the like. An exhaust gas passage 4 is formed by surrounding the outer periphery of the first heat exchanger 2 with a small gap, and a hollow cylindrical second exhaust gas passage 4 is formed below the first heat exchanger 2 to form a combustion chamber 5. The second heat exchanger 2 is made of stainless steel or the like, like the first heat exchanger 2. 6 is a connecting pipe for connecting the first heat exchanger 2 and the second heat exchanger 3 in series, 7 is a hot water return port provided in the first heat exchanger 2, 8
Is a hot water inlet provided at the upper part of the second heat exchanger 3, and 9 is the first
The communication port 10 provided in the heat exchanger 2 of the second heat exchanger 3
, 11 is a top plate, 12 is an exhaust pipe, 1
3 is an exhaust gas passage formed between the top plate 11 and the upper surface of the first heat exchanger 2, and 14 and 15 are first exhaust gas passages 4 forming the exhaust gas passage 4.
These are a plurality of concave ribs formed on the wall portions of the heat exchanger 2 and the second heat exchanger 3, and may be provided at positions shifted from each other in the vertical direction.

The second heat exchanger 3 comprises an inner cylinder 16 and an outer cylinder 1
The inner cylinder 16 surrounds the upper part of the combustion burner 1 and forms the combustion chamber 5 on the upper part.
The outer peripheral wall of the heat exchanger 2 is surrounded at a small interval to form an exhaust gas passage 4. The outer cylinder 17 has upper and lower ends at the inner cylinder 1.
1 is fixed to the inner cylinder 1 in a watertight manner by welding or the like.
6 form a water wall layer 18 formed therebetween. Further, the first heat exchanger 2 has a communication port 9 connected to the communication port 10 of the second heat exchanger 3 and a connection pipe 6 on one side, and is located on the opposite side to return hot water. A mouth 7 is provided.

Next, the operation of the first embodiment having the above configuration will be described. First, as the flow of hot water,
The low-temperature water of about 40 ° C., which has released heat from the hot water return port 7 of the heat exchanger 2 by a radiator (not shown), enters the first heat exchanger 2 and the first heat exchanger 2 After being heated in the water 2 and heated to a temperature of about 55 ° C., the water is passed through the connecting pipe 6 through the connecting port 9 on the opposite side and from the connecting port 10 of the second heat exchanger 3 to the second port.
Into the lower part of the heat exchanger 3. The warm water of about 55 ° C. that has entered the lower part of the second heat exchanger 3 moves from the lowermost part to the upper part of the water wall layer 18 formed between the inner cylinder 16 and the outer cylinder 17,
The temperature is raised to about 70 ° C. hot water from a hot water outlet 8 provided at the upper part of the second heat exchanger 3, sent to the outside, and guided again to a circulation circuit to a radiator.

On the other hand, when the combustion burner 1 is burned, the combustion gas rises in the combustion chamber 5 along the lower inner peripheral wall of the inner cylinder 16, and the bottom of the first heat exchanger 2 and the second heat exchanger The inner peripheral wall of No. 3 is directly heated. At this time, the temperature of the combustion gas in the lower part of the combustion chamber 5 is about 1300 ° C., and the temperature of the combustion gas in the upper part of the combustion chamber 5, that is, near the bottom of the first heat exchanger 2 is about 700 to 800 ° C. It is. The combustion gas whose temperature has dropped due to the heat reception passes through the narrow exhaust gas passages 4 and 13 and is exhausted from the exhaust port 12. The temperature of the combustion gas passing through the exhaust gas passage 4 is about 300 to 350 ° C. When passing through the path 4, repeated contact with the plurality of concave ribs 14 and 15 causes disturbance in the flow of exhaust gas,
The heat exchange in this section is performed efficiently. Further, when the combustion gas passes through the next exhaust gas passage 13, the combustion gas heats the upper surface of the first heat exchanger 2 and is exhausted to the outside as exhaust gas having a temperature of about 180 to 220 ° C. from the exhaust port 12.

As described above, the first cylindrical heat exchanger 2 and the hollow cylindrical second heat exchanger 3 each formed of stainless steel or the like are connected in series, and both heat exchangers are connected. Since a plurality of concave ribs 14 and 15 are respectively formed in the portions facing the exhaust gas passage 4 in 2 and 3, the heat exchanger can be manufactured at low cost, and the flow of the combustion gas is disturbed when passing through the exhaust gas passage 4. Is generated, the heat exchangers 2 and 3 are in good contact with each other, and heat is effectively exchanged up to the low-temperature combustion gas whose temperature has dropped. In addition, the direction in which the hot water flows into the hot water return port 7 and the direction in which the combustion gas flows through the exhaust gas path 4 are opposite to each other, and are close to the counter flow. Heat exchange is performed with the low-temperature combustion gas at 350 ° C., and a large temperature difference can be obtained, so that effects such as further improving the heat exchange rate can be obtained.

Embodiment 2 FIG. In the first embodiment, the plurality of concave ribs 14 and 15 are formed on the portions of the heat exchangers 2 and 3 facing the exhaust gas passage 4, respectively. However, the concave ribs may be formed on at least one of the peripheral walls. , A certain effect can be obtained.

Embodiment 3 FIG. 3 shows a third embodiment of the present invention, in which a hot water return port 7 is provided in the second heat exchanger 3 and a hot water outlet 8 is provided in the first heat exchanger 2. The flowing direction and the flowing direction of the combustion gas become the same direction,
Finally, the temperature dropped to about 70-70 ℃ and the temperature dropped to about 300-35.
Heat exchange occurs with the low-temperature combustion gas at 0 ° C., and the temperature difference becomes smaller than in the case of the first embodiment shown in FIG. 1, so that the heat exchange rate is slightly inferior, but almost the same effect can be obtained. .

[0016]

As described above, according to the present invention, according to the first aspect, heat can be efficiently received from high-temperature combustion gas to low-temperature combustion gas, so that a heat exchanger can be manufactured from inexpensive stainless steel or the like. A hot water boiler with a high rate can be provided.

According to the second aspect of the present invention, the efficiency of receiving heat from the low-temperature combustion gas can be further improved.

According to the third aspect of the present invention, the exhaust gas
Since the flow of the hot water passing through the hot water return port is close to the counterflow with respect to the flow of the combustion gas passing through the passage , the heat exchange rate can be further improved.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a first embodiment of a hot water boiler according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a side sectional view showing Embodiment 1 of the hot water boiler according to the present invention.

FIG. 4 is a sectional view showing a heat exchanger part of a conventional hot water boiler.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Combustion burner, 2 1st heat exchanger, 3 2nd heat exchanger, 4 exhaust gas path, 5 combustion chamber, 6 connection pipe, 7
Hot water return port, 8 Hot water outlet, 9, 10 Contact, 14,
15 Concave rib.

Continuation of the front page (56) References JP-A-10-38380 (JP, A) JP-A-63-101654 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24H 1 / 30 F24H 1/24

Claims (3)

(57) [Claims] 1. A combustion burner, a first heat exchanger having a cylindrical shape provided at an upper portion of the combustion burner, and a small gap formed around an outer periphery of the first heat exchanger. And surround
To form an exhaust gas path, and a lower part of the first heat exchanger is
A hollow cylindrical second heat exchanger forming a baking chamber; one of the first heat exchanger and the second heat exchanger is provided with a hot water return port and a communication port; A first heat exchanger and a second heat exchanger are connected in series by providing an outgoing port and a communication port to connect the two communication ports by a connecting pipe, and a first heat exchange facing the exhaust gas path is performed. A hot water boiler, wherein a plurality of concave ribs are formed on at least one peripheral wall of the heat exchanger and the second heat exchanger. 2. The hot water boiler according to claim 1, wherein the concave rib is formed on both an outer peripheral wall of the first heat exchanger and an inner peripheral wall of the second heat exchanger. 3. A combustion gas passing through an exhaust gas passage , wherein a hot water return port and a communication port are provided in the first heat exchanger, and a hot water outflow port and a communication port are provided in an upper part and a lower part of the second heat exchanger. 2. The hot water boiler according to claim 1, wherein a flow of the hot water passing through the hot water return port is substantially opposite to the flow of the hot water.