KR20040098305A - Heat exchanging systems of boiler and boiler structures using them - Google Patents

Abstract

PURPOSE: A heat exchanging system for a boiler and a structure of the boiler using the same are provided to reduce the size of a main heat exchanger. CONSTITUTION: A heat exchanging system for a boiler is composed of a storage type main heat exchanger(30) having a cylindrical body, a thermal-energy storage tank(40) for storing heating water, and a hot-water coil(50) installed at the inside of the thermal-energy storage tank. A burner is mounted to the upper part of the cylindrical body. The main heat exchanger includes upper and lower water chambers formed at the inside of the cylindrical body, a plurality of water pipes connected to the water chambers, heating plates disposed between the water pipes, and flues having a central flue and outer flues formed between the water pipes. Combustion heat generated by the burner passes through the central flue downward, and flows along the outer flues upward. The thermal-energy storage tank includes inner circulation connectors(412,414) connected to the main heat exchanger, a heating-water supply unit(424), and a heat-water returning unit(422).

Description

Heat exchanger system of domestic boiler and boiler structure using it {HEAT EXCHANGING SYSTEMS OF BOILER AND BOILER STRUCTURES USING THEM}

The present invention relates to a heat exchanger structure of a domestic boiler and a structure of a domestic boiler using the same, and more particularly, to overcome the disadvantages of an instant heat exchanger using a low temperature heat exchanger, while ensuring abundant water supply capacity and hot water capacity. In particular, the present invention relates to a heat exchanger structure of a domestic boiler and a boiler structure of a domestic boiler using the same, capable of overcoming the limitation of the installation space by reducing the size.

In recent years, due to the change in residential culture, it has become disadvantageous to install a separate boiler room due to the change of housing type into apartments such as apartments or villas rather than single houses. Therefore, the boiler is often installed to occupy a part of the space such as the veranda. When the boiler is installed in such a space, the boiler is installed on one side to prevent the effectiveness of the space, such as a veranda, in which the boiler is installed, or is often attached to a wall such as a wall-mounted type. The hot water boiler has the advantage of abundant water capacity and the increase of hot water capacity, but the size of the heat exchanger is large to cover the water capacity and hot water capacity. there was.

In more detail, the conventional low-temperature heat exchanger has a predetermined space for storing the heating water therein for the heat storage function, and has a cylindrical shape for uniform heating of the heating water as well as a built-in hot water coil. In particular, the size of the heat exchanger, in particular, the cross-sectional area is large, the boiler was also large.

Therefore, the efficiency of the space in which the boiler is installed is reduced, and in particular, in the case of the wall-mounted type, the width of the boiler casing is large, so that the part protruding from the wall has become a constraint for utilizing the aesthetic appearance or the installation space for other purposes.

In addition, since the heat exchanger occupies a large volume, even if other components are arranged in the side of the heat exchanger in the boiler casing, there is a lot of empty space inside the casing. .

For this reason, a boiler is sometimes used to install in a narrow installation space with a wall-mounted type, but the boiler is not suitable for the heating structure of ondol heating system due to its low water capacity. Has a limited lifespan, and some of the heating or hot water pipes passing through the heat exchanger are locally damaged by high temperature heating.

In addition, in recent years, as the bath culture in the home is activated, the desire to use abundant hot water is increasing, but there is a limit to the increase in the hot water capacity of the instant boiler.

Therefore, the low water type heat exchanger suitable for the ondol residential culture like Korea ensures abundant irrigation capacity and increases the hot water capacity, while efficiently constituting each component of the boiler in the boiler casing to minimize the size and width of the boiler. It is desirable to develop a domestic boiler that can minimize the constraints of the installation space.

The present invention has been made to solve the above problems, by separating the function of the low-temperature heat exchanger into the main heat exchanger and the heat storage tank, and by embedding the hot water coil in the heat storage tank, it is possible to ensure abundant water supply capacity and hot water capacity, but the main heat exchanger It is an object of the invention to provide a heat exchange system for a domestic boiler that is capable of reducing the size of the furnace.

In addition, the present invention by using the heat exchange system of the domestic boiler to reduce the size of the main boiler type heat exchanger so that each component of the boiler can be efficiently placed in the boiler casing to minimize the size of the boiler, in particular the width of the boiler to install the boiler It is another object of the invention to provide a boiler structure for homes that can overcome the space constraints.

1 is a schematic view for explaining a heat exchange system of a domestic boiler according to the present invention.

2 is a view for explaining the structure of the main heat exchanger according to an embodiment of the present invention.

3 is a plan sectional view for explaining the structure of the main heat exchanger shown in FIG.

4 is a view for explaining the structure of the main heat exchanger according to another embodiment of the present invention.

5 is a view for explaining the structure of a domestic boiler according to the present invention.

FIG. 6 is a plan view of the household boiler shown in FIG. 5 as viewed from above. FIG.

* Explanation of the symbols in the main part of the drawing

10: boiler casing 20: blower

30: main heat exchanger 40: heat storage tank

50: hot water coil 60: internal circulation pump

70: external circulation pump 310: body

312: heating water inlet 314: heating water outlet

322: lower chamber 324: upper chamber

334: water pipe 342: internal heating plate

352, 372: central year 354: outer year

362: blister 374: combustion chamber

376: associative 380: downfire burner

412, 414: internal circulation connector 422: heating return port

424: heating water supply port

In order to achieve the above object, the present invention provides a low-heat type heat exchanger with a heating water flowing inside the body while the combustion heat of the burner built in through the cylindrical body communicated through other pipes and connectors outside is circulated along the flue. Main heat exchanger; The heating water is stored inside the main body formed with an internal circulation connector connected to each of the connection ports of the main heat exchanger, a heating water supply port for supplying heating water to an external pipe, and a heating water return port for returning the heating water circulated through the external pipe. Internal air is discharged through the opening formed in the upper portion of the heat storage tank is the internal pressure is adjusted to the same as the external atmospheric pressure; And a coil-shaped hot water coil embedded in the heat storage tank.

Preferably, the main heat exchanger, the burner is a burning burner which is built into the upper portion of the cylindrical body as the burner, the water chambers formed in the upper and lower portions of the inner cylindrical body corresponding to each of the connector, and in communication with the vertical chamber A plurality of water pipes disposed to form a plurality of water pipe rows spaced apart from each other, a heating plate disposed between the plurality of water pipe rows, and a heat of combustion of the burner is downwardly flowed along the central year of the burner to lower the heat plate. It is provided with a down-combustion type water pipe heat exchanger structure is formed so that the flue flows upward along the outer peripheral flue formed between the plurality of water pipes to the outside of the heating plate.

Alternatively, the main heat exchanger, the burner is a burner type burner which is built into the upper side of the cylindrical body as the burner, is communicated through the connector and the blister formed in the body and the central flue of the combustion heat flows downward to the burner And a combustion chamber formed in the central flue and the lower side, and a plurality of associations communicating with the combustion chamber and extending upward through the blister inward to the outside of the central flue, the combustion heat flowing downward through the central flue. It is characterized by heat exchange with the heating water in the blister while flowing upward through the association through the chamber.

In addition, the present invention, in order to achieve the above another object, the casing of the boiler; A blower mounted to an upper portion of the boiler casing; It is installed in the lower portion of the blower, the body is formed in the upper and lower both sides so as to communicate with each other corresponding to the external pipes, the combustion burner built in the upper portion of the upper body connected to the blower, and each of the connector A plurality of water pipes formed in the upper and lower parts of the body and connected to the upper and lower water chambers, the plurality of water pipes being spaced apart from each other to form a plurality of water pipe rows, and a heating plate disposed between the plurality of water pipe rows. The heat of combustion of the burner flows downward along the central year under the burner and flows down the heating plate and upwardly flows along the outer circumferential flue formed between the plurality of water pipes outside the heating plate to exhaust the exhaust gas through an exhaust pipe connected to the blower and blower. A main heat exchanger formed so that flue is formed; Is disposed on the side of the main heat exchanger, the upper and lower inner circulation connector connected to each of the connector of the main heat exchanger, the heating water supply port for supplying the heating water to the external pipe, and the heating water return port for returning the heating water circulated through the external pipe A heat storage tank in which heating water is stored in the formed main body, the internal air is discharged through the opening formed in the upper part of the main body, and the internal pressure is controlled to be equal to the external atmospheric pressure; A coil-shaped hot water coil embedded in the heat storage tank; An internal circulation pump disposed below the heat storage tank and installed between a lower internal circulation connector formed in the heat storage tank and a connection hole formed at a lower portion of the main heat exchanger body to circulate heating water between the main heat exchanger and the heat storage tank; It is disposed on the side of the inner circulation pump, installed between the heating water supply portion and the outer pipe of the heat storage tank external circulation pump for circulating the heating water between the external pipe and the heat storage tank; household boiler structure comprising a To provide.

1 to 4 are views for explaining the heat exchange system of the domestic boiler according to the present invention, Figures 5 and 6 are views for explaining the structure of the domestic boiler using the heat exchange system of the domestic boiler.

The heat exchange system of the domestic boiler according to the present invention includes a low-temperature main heat exchanger and a heat storage tank, and a hot water coil built in the heat storage tank, in which the heat of combustion of the burner is distributed along the year.

According to the present invention, it is possible to secure abundant water supply capacity and hot water capacity while reducing the size of the main heat exchanger. Therefore, in the domestic boiler using the heat exchange system of the domestic boiler, it is possible to intensively arrange each component in the boiler casing, so that it is possible to reduce the size of the boiler, in particular, the width of the boiler. It can be installed in various places.

The heat exchange system of the domestic boiler according to the present invention includes a heat storage tank in communication with the main heat exchanger and the main heat exchanger, and a hot water coil embedded in the heat storage tank.

In the heat exchange system according to the present invention, unlike the conventional low-heat type heat exchanger, the main heat exchanger 30 bears a part of the heat storage function, but the heat storage function is handled by the heat storage tank 40 formed separately. Since it is possible to reduce the size of the space in which the heating water is stored, it is possible to reduce the size of the main heat exchanger (30). In addition, since the hot water coil 50 is not built in, it is possible to further reduce the size of the main heat exchanger 30, thereby reducing the occupied space occupied individually by each component in the boiler while ensuring abundant water capacity and hot water capacity. Bars, it is possible to arrange each component intensively in the boiler casing.

The main heat exchanger of the heat exchange system according to the present invention passes through the cylindrical body and the heat of combustion of the built-in burner flows along the year while the heat exchange with the heating water inside the body flowing while flowing in and out through the connector formed on the upper and lower sides of the body. A hot dip heat exchanger is used. Preferably, a heat exchanger that implements a downward combustion method capable of maximizing thermal efficiency despite the small size is preferably used.

The main combustion heat exchanger according to the present invention has a two-pass structure in which the combustion heat has two distribution paths, the downward flow and the upward flow, and the heating water inside the heat exchanger is doubled by the combustion heat, so that the heating is heated by a small amount of combustion heat. The amount of water is increased to maximize combustion efficiency.

Referring to the internal structure of an embodiment of the main heat exchanger according to the present invention with reference to Figures 2 and 3, the downward burner 380 is mounted above the cylindrical body 310 of the main heat exchanger, the cylindrical body 310 The upper and lower portions respectively correspond to the connector. The connector formed at the lower side of the cylindrical body 310 is a heating water inlet 312 through which heating water is introduced from the heat storage tank 40, and the connector formed at the upper side of the body is discharged to the heat storage tank by heating the heated water inside the main heat exchanger 30. Heating water discharge outlet 314 is.

The upper and lower ends of the cylindrical body 310 are provided with upper and lower chambers 324 and lower chambers 322, and the upper and lower chambers 324 and 322 are communicated by a plurality of water pipes 332 and 334. have.

3 is a plan sectional view showing the arrangement of the water pipes, a central year 352 is formed at the center of the main heat exchanger 30 under the burner 380, and the central year 352 is concentrically arranged around the center year 352. An inner water pipe row in which a plurality of inner water pipes 332 arranged to be spaced apart from each other is formed. An inner heating plate 342 is installed outside the inner water pipe row.

When the plurality of outer water pipes 334 are concentrically arranged to the outside of the inner heating plate 342, they are spaced apart from each other to form an outer water pipe row. The outer heating plate 344 is provided to the outside of the outer water pipe row, the inside of the body. The inner heating plate 344 is a member extending downward from the upper end of the body 310, the lower end is spaced apart from the lower end of the main heat exchanger (30) by a predetermined interval. The outer heating plate 334 extends downward from the inner upper end of the main heat exchanger 30 to be in contact with the lower upper end of the inner side of the main heat exchanger, that is, the upper end of the lower chamber 322, and the body 310 of the main heat exchanger 30 is formed. It may be formed integrally with).

The flue of the main heat exchanger 30 according to the present invention includes the central flue 352 and the following outer circumferential flue 354. The combustion gas of the burner 380, i.e., the heat of combustion is a and As it flows downward along the central year 352, and flows outward through the lower side of the inner heating plate 342 and is upwardly distributed along the space between the outer water pipes 334, that is, the outer circumferential year 354, through the exhaust pipe. Discharged through.

The inner water pipe 332 and the outer water pipe 334 may be arranged to be in contact with the inner heating plate, and may be spaced apart at predetermined intervals.

The heating water introduced from the heating water inlet 312 flows through the lower water chamber 322 to the upper water chamber 324 in the b direction through the water pipes 332 and 334 while being heated while exchanging heat with the combustion heat around the water pipes 332 and 334. And flows out of the main heat exchanger 30 through the heating water discharge port 314.

The main heat exchanger 30 according to an embodiment of the present invention uses a heat exchanger having a water pipe type as described above to increase combustion efficiency. The water pipe type heat exchanger refers to a type of heat exchange with the heating water flowing through the water pipe by the combustion gas flowing through the water pipe while the heating water flows. The heat exchange system according to the present invention is not limited to the water pipe type, but may be composed of an associated type of heat exchange with the heating water around the associated pipe while the combustion gas passes through the inside of the blister.

4 is a view showing another embodiment of the main heat exchanger according to the present invention. Referring to the main heat exchanger of the associated type compared to the structure of the heat pipe type heat exchanger described above, a blister 362 is provided inside the cylindrical body 310, the blister 362 is the heating water inlet of the upper and lower sides of the body It communicates with the outside of the main heat exchanger 30 through 312 and the heating water discharge outlet 312 and 314.

A central flue 372 is formed below the downward combustion burner 380 embedded above the cylindrical body and the combustion heat of the burner is downwardly formed, and a combustion gas chamber 374 is formed below the central flue. A plurality of plumbing 376 is provided in communication with the combustion gas chamber 374 and passing inside the blister 362 outside the central flue. That is, unlike the water pipe type, the combustion gas flows downward through the central flue 372 and flows upward through the associated chamber 376 through the combustion chamber 374 and heat exchanges with the heating water in the blister 362. The central flue 372 at the bottom of the burner 380 may be configured to have a stepped portion such that the combustion gas flows downward through an association formed between the central flue 372 and the combustion chamber 374 at the stepped portion. 4, the flow of such combustion gas is indicated by an arrow.

In the main heat exchanger according to the present invention, since both the heat pipe type and the associated type of combustion heat are distributed through a two-pass path of the central year and the associated year or the outer year, the heat efficiency is increased and the heating water is excellent despite the small size.

In addition, the heat exchange system of the domestic boiler according to the present invention by using a low-temperature heat exchanger having a water chamber or a blister inside the cylindrical body as a main heat exchanger, it is possible to ensure a sufficient capacity of water flowing through the water chamber or blister Therefore, it is possible to prevent the whitening phenomenon that may occur due to the use of the instantaneous heat exchanger.

In addition, although the configuration and control of the fuel supply pipe is complicated so that each of the plurality of Bunsen burners generates the same combustion heat, in the present invention, the configuration is simplified by using the low-heat type heat exchanger, and a certain amount of the internal heat exchanger is used. Since the heating water is filled, it becomes possible to solve the problem that the heat exchanger is damaged by local heating as in the instant heat exchanger, thereby increasing the durability of the heat exchanger and the durability of the boiler itself.

Each of the heating water inlet 312 and the heating water discharge port 314 of the main heat exchanger 30 communicates with the heat storage tank 40. The heat storage tank 40 according to the present invention has an opening 406 on the side of the cylindrical body 405 to maintain the pressure inside the boiler equal to the external atmospheric pressure and discharge the air inside the boiler. It is an integrated heat storage tank. Since the expansion tank and the heat storage tank are integrally formed, not only the piping and the valve structure between the expansion tank and the heat storage tank can be omitted, but also it is possible to minimize the occupied area inside the boiler. In addition, it means that the storage space of the heating water is increased as the installation space of the reduced pipes and valves, it is easier to increase the capacity of the water stored in the heat storage tank and change the size of the hot water coil.

The upper and lower sides of the cylindrical body 405 of the heat storage tank 40 are formed with internal circulation connectors 412 and 414, which are passages through which the heating water is circulated in relation to the main heat exchanger 30, and the heating water is connected to the heat storage tank 40. The heating water supply port 424 and the heating water return port 422 are provided to circulate between the external pipes. The heating port supply port 424 is connected to the external circulation pump 70 and the heating water is circulated through the heating water supply line 12 in the heat storage tank 40 by the operation of the external circulation pump 70 and then heated. It returns to the heat storage tank 40 via the heating return port 422 through the return line 14.

Preferably, the heat storage tank 40 further includes an extension pipe 424-a connected to the heating water supply port 424 and extended upward, so that the heating water introduced into the upper internal circulation connector 414 is flowed by the heating water supply. Enable direct supply to supply port 424.

Inside the heat storage tank 40 according to the present invention is a coil-shaped hot water coil 50 is embedded. Cold water from the cold water supply line 510 flows in through the lower end of the hot water coil 50 and is heated by heat exchange with the heating water in the heat storage tank 40, through the hot water supply line 520 at the upper end of the hot water coil 50. Discharged.

According to the present invention, the main heat exchanger 30 and the heat storage tank 40 are separated, and the hot water coil 50 is provided with a heat exchange system built in the heat storage tank 40, thereby providing abundant water capacity by the heat storage tank 40. While it is possible to secure it, it is possible to reduce the size of the main heat exchanger 30, and it is easy to increase the hot water coil without changing the structure of the main heat exchanger 30, thereby making it easy to secure the hot water capacity.

The middle water level sensor 410 is installed at the middle of the outer circumferential surface of the heat storage tank 40, and the low water level sensor 420 is installed to be spaced a predetermined distance below the middle water level sensor 410. The heat storage tank according to the present invention is capable of ensuring a buffer amount between the installation position of the middle water level sensor 410 and the low water level sensor 420 due to the double water level sensor, each of the water level sensor is connected to the control panel 80 If water replenishment is required, it is configured to enable automatic replenishment.

5 and 6 show the structure of a domestic boiler using the heat exchange system of the domestic boiler described above.

Referring to the drawings, a blower 20 is installed at one side of the casing 10 of the boiler, and a low temperature main heat exchanger 30 is disposed below the blower 20. In the boiler casing 10, an integral heat storage tank 40 having an expansion tank function and a heat storage function is disposed at a side of the main heat exchanger, and the heat storage tank 40 includes a hot water coil 50. In addition, an internal circulation pump 60 and an external circulation pump 70 are disposed below the heat storage tank.

Each component of the domestic boiler can be controlled by a control unit 80 for controlling the operation of the boiler and an indoor controller installed indoors as is known.

The boiler structure according to the present invention uses the above-described heat exchange system, thereby ensuring abundant irrigation capacity and hot water capacity, and efficiently constituting each component in the boiler casing to reduce the size of the boiler, in particular, the width (t) of the boiler. It is possible to reduce and thus to be installed in various places without reducing the effectiveness of the space in which the boiler is installed.

One side of the boiler casing 10 is installed on the upper side of the air blower 20, the home boiler according to the present invention can be installed in various types of air blower, but to minimize the size of the boiler by a single motor It is preferable to use a blower manufactured and sold by Cricket Co., Ltd., in which exhaust can be realized simultaneously. Thus, since the blower 20 is installed, it is possible to realize complete combustion with low noise regardless of the flow of external air while occupying a small occupied space. Although not indicated by reference numerals, the blower includes an intake pipe and an exhaust pipe communicating with the upper side of the boiler casing 10.

The main heat exchanger 30 is installed below the blower 20. The main heat exchanger is in communication with the heat storage tank 40 disposed to the side of the main heat exchanger 30 through the heating water inlet 312 and the heating water discharge port 314, the hot water coil is built in the heat storage tank. Thus, by separating and realizing each function of the heat exchanger of the low boiling water boiler by the main heat exchanger 30 and the heat storage tank 40, it is possible to reduce the size of the main heat exchanger 30. Reducing the size of the main heat exchanger (30) is to reduce the width (t) of the boiler similar to the reduced size of the main heat exchanger (30) in view of the overall size of the boiler. In addition, since the heat storage tank 40 and the pumps 60 and 70 can be disposed on the side of the main heat exchanger 30, it is possible to intensively arrange each component of the boiler in each space in the boiler casing.

The domestic boiler structure according to the present invention implements an internal and external double independent circulation method by separately installing the internal circulation pump 60 and the external circulation pump 70 under the heat storage tank 40.

The connection and action of the internal circulation pump 60 and the external circulation pump 70 have been described above in the description of the heat exchange system of the domestic boiler. In detail, the internal circulation pump 60 is a circulating pump for the purpose of heat exchange for circulating heating water between the main heat exchanger 30 and the heat storage tank 40, and the external circulation pump 70 is external as described above. It is a circulation pump for the purpose of heating the circulation of the heating water between the pipe and the heat storage tank (40).

In the hot water mode, only the internal circulation pump 60 is driven and the hot water heated by the main heat exchanger 30 circulates between the heat storage tank 40 and the main heat exchanger 30, and the hot water is exchanged with water circulating the hot water coil. To supply. In the heating mode, the internal circulation pump 60 and the external circulation pump 70 are driven together.

As described above, since the inner circulation pump 60 for heat exchange and the outer circulation pump 70 for heating are separately installed, rapid heating is possible, and hot water is more quickly supplied.

The heating water supply port 424 of the heat storage tank 40 includes an extension pipe 424-a extending upward from the heat storage tank 40, and the heating water heated by heat exchange in the main heat exchanger 30 is internally circulated pump. When circulated by the pump pressure of (60), the heating water flows into the inner circulation connector 414 and the extension pipe (424-a) by the pump pressure and temperature gradient of the inner circulation pump 60 and the outer circulation pump 70 By flowing to the side to flow directly into the heating water supply port 424, it is configured to enable faster heating.

Reference numeral 15 in the drawing indicates a fuel supply line.

Although the present invention described above has been described with reference to some embodiments, the present invention is not limited thereto, and variations of the present invention that can be easily implemented by those skilled in the art belong to the technical idea of the present invention. .

According to the present invention, the function of the conventional low-temperature type heat exchanger is separated into a low-temperature main heat exchanger, a heat storage tank, and a hot water coil embedded in the heat storage tank, thereby ensuring abundant water supply capacity and hot water capacity, while providing a cylindrical main heat exchanger. It is possible to reduce the size, in particular the cross-sectional area, so that it is possible to reduce the size of the boiler, in particular the width t. In particular, since the heat storage tank is separated from the heat exchanger and formed separately, it is easy to increase the water capacity and the hot water capacity of the hot water coil embedded therein.

In addition, the domestic boiler structure according to the present invention has a low-temperature heat exchanger structure that can ensure a constant irrigation capacity by a blister or a water chamber inside the main heat exchanger, so that it can occur in the instantaneous heat exchanger while having a rapid heating and rapid hot water supply function. It is possible to increase the durability of the heat exchanger and the durability of the boiler by solving problems of whitening and local heating.

In addition, the domestic boiler according to the present invention is separated into a heat storage tank having a conventional heat exchanger function and the main heat exchanger and hot water coil, thereby reducing the space occupied by the conventional heat exchanger in the boiler casing intensively arranged each component It is possible to reduce the size of the boiler, in particular the width (t) does not reduce the effectiveness of the installation space in which the boiler is installed, it is possible to install in a variety of spaces.

Claims (4)

A low-temperature main heat exchanger, through which a combustion heat of a built-in burner passes through a cylindrical body communicated through other pipes and connectors externally and is heat-exchanged with the heating water flowing in the body while flowing along the flue; The heating water is stored inside the main body having a heating water supply port for supplying heating water to the inner circulation connection port and the external pipe connected to each of the connection ports of the main heat exchanger, and a heating water return port for returning the heating water circulated through the external pipe. A heat storage tank through which the internal air is discharged through the opening formed in the upper part, and the internal pressure is controlled to be equal to the external atmospheric pressure; And And a coil-shaped hot water coil embedded in the heat storage tank. According to claim 1, wherein the main heat exchanger, As the burner, a downward combustion burner mounted above the cylindrical body is mounted. A plurality of water pipes corresponding to each of the connectors and formed in upper and lower portions of the cylindrical body, connected to and connected to the upper and lower water chambers, and spaced apart from each other to form a plurality of water pipe rows, and disposed between the plurality of water pipe rows. And a flue heat flowing downwardly along the central year below the burner and flowing upward through the outer circumference formed between the plurality of water pipes to the outside of the heating plate. Heat exchange system of a domestic boiler, characterized in that. According to claim 1, wherein the main heat exchanger, As the burner, a downward combustion burner mounted above the cylindrical body is mounted. A blister formed in the cylindrical body and communicated through the connector and a central flue flowing combustion heat downwardly to the lower side of the burner; and a combustion chamber chamber formed at the lower side of the central flue and the combustion chamber and communicating with the combustion chamber chamber. Comprising a plurality of associations extending upward through the inside of the blister, the heat of combustion flows downward through the central flue flows upward through the association through the combustion chamber chamber and heat exchange with the heating water in the blister Heat exchange system of domestic boiler. Casing of the boiler; A blower fan mounted to an upper portion of the boiler casing; A cylindrical body installed at a lower portion of the blower and having a connection port formed at both upper and lower sides thereof so as to communicate with other external pipes, respectively, and a combustion burner built in the upper portion of the cylindrical body and connected to the blower; A plurality of water pipes corresponding to each of the connectors and formed in the upper and lower parts of the body, the plurality of water pipes connected to and connected to the upper and lower water chambers, and spaced from each other to form a plurality of water pipe rows, and a heating plate disposed between the plurality of water pipe rows. And exhaust heat of the burner flows downward along the central year under the burner and flows down the heating plate to upwardly along the outer circumferential flue formed between the plurality of water pipes outside the heating plate to connect the exhaust pipe connected to the air blower. Cold water type main heat exchanger is formed so that the flue is exhausted through; Is disposed on the side of the main heat exchanger, the upper and lower inner circulation connector connected to each of the connector of the main heat exchanger, the heating water supply port for supplying the heating water to the external pipe, and the heating water return port for returning the heating water circulated through the external pipe A heat storage tank in which heating water is stored in the formed main body, the internal air is discharged through the opening formed in the upper part of the main body, and the internal pressure is controlled to be equal to the external atmospheric pressure; A coil-shaped hot water coil embedded in the heat storage tank; An internal circulation pump disposed below the heat storage tank and installed between a lower internal circulation connector formed in the heat storage tank and a connection hole formed at a lower portion of the main heat exchanger body to circulate heating water between the main heat exchanger and the heat storage tank; And The boiler structure is disposed on the side of the inner circulation pump, characterized in that it comprises an external circulation pump installed between the heating water supply and the external pipe of the heat storage tank circulating the heating water between the external pipe and the heat storage tank.