CN221526872U

CN221526872U - Gas water heater

Info

Publication number: CN221526872U
Application number: CN202323666120.9U
Authority: CN
Inventors: 邱步; 李伟; 王以龙
Original assignee: Aosmith China Water System Co ltd; AO Smith China Water Heater Co Ltd
Current assignee: Aosmith China Water System Co ltd; AO Smith China Water Heater Co Ltd
Priority date: 2023-12-29
Filing date: 2023-12-29
Publication date: 2024-08-13
Anticipated expiration: 2033-12-29

Abstract

The utility model discloses a gas water heating device, which comprises: the water flowing into the heat exchanger exchanges heat with the flue gas generated by the burner and then flows out of the heat exchanger; the heat exchanger comprises a primary heat exchanger and a secondary heat exchanger, and the primary heat exchanger and the secondary heat exchanger are sequentially arranged along the flow direction of the flue gas; the secondary heat exchanger comprises a shell with a preset volume and a heat exchange tube penetrating through the inner cavity of the shell, wherein the interior of the heat exchange tube is used for circulating smoke, and the smoke entering the heat exchange tube exchanges heat with water contained in the inner cavity of the shell through the heat exchange tube; the gas water heating device also comprises a bypass waterway, and the bypass waterway is connected with the heat exchanger in parallel; the internal circulation waterway can be formed in the gas water heating device and comprises a shell inner cavity, a primary heat exchanger and a bypass waterway. The utility model can improve the comprehensive use experience of the user while realizing energy conservation and environmental protection.

Description

Gas water heater

Technical Field

The utility model relates to the technical field of water heaters, in particular to a gas water heating device.

Background

The existing water heater mainly comprises: gas water heater, solar water heater, air energy heat pump water heater, electric water heater, etc. The gas water heater is taken as a typical instant water heater and mainly comprises a fan, a combustor, a heat exchanger and other parts.

For the gas water heater, how to improve comprehensive use experience of a user while saving energy and protecting environment is a technical problem to be solved at present, and is a direction of continuous optimization and improvement in the long term in the future.

Disclosure of utility model

Aiming at the defects existing in the prior art, the embodiment of the utility model provides the gas water heating device which can improve the comprehensive use experience of a user while realizing energy conservation and environmental protection.

The specific technical scheme of the embodiment of the utility model is as follows:

A gas water heating apparatus, the gas water heating apparatus comprising:

The device comprises a combustor, a heat exchanger and a fan, wherein water flowing into the heat exchanger exchanges heat with flue gas generated by the combustor and then flows out of the heat exchanger;

The heat exchanger comprises a primary heat exchanger and a secondary heat exchanger, and the primary heat exchanger and the secondary heat exchanger are sequentially arranged along the flow direction of the flue gas;

The secondary heat exchanger comprises a shell with a preset volume and capable of containing water and a heat exchange tube penetrating through the inner cavity of the shell, wherein the interior of the heat exchange tube is used for circulating smoke, and the smoke entering the heat exchange tube exchanges heat with the water contained in the inner cavity of the shell through the heat exchange tube;

The gas water heating device further comprises a bypass waterway, and the bypass waterway is arranged in parallel with the heat exchanger;

An internal circulation waterway can be formed in the gas water heating device, the internal circulation waterway is provided with a water pump, and the internal circulation waterway comprises an inner cavity of the shell, the primary heat exchanger and the bypass waterway; and under the action of the water pump, water in the internal circulation waterway can circulate.

In a preferred embodiment, the secondary heat exchanger further has a heat insulation structure for insulating the housing interior.

In a preferred embodiment, the insulating structure is an insulating layer surrounding the outside of the housing.

In a preferred embodiment, the insulating structure is a cavity provided outside the housing, the cavity being constituted by a void provided between a jacket provided outside the housing and the housing.

In a preferred embodiment, the cavity outside the housing communicates with the heat exchange tube, and flue gas flowing out of the heat exchange tube flows into the cavity outside the housing.

In a preferred embodiment, the housing interior and the primary heat exchanger are arranged in series or parallel in the direction of water flow.

In a preferred embodiment, the gas water heating device further comprises a water inlet pipe and a water outlet pipe which are communicated with the heat exchanger, wherein water flowing through the water inlet pipe flows into the heat exchanger, exchanges heat with flue gas generated by the burner, flows out of the heat exchanger and flows into the water outlet pipe; the bypass waterway comprises a bypass pipe, one end of the bypass pipe is connected with the water outlet pipe, and the other end of the bypass pipe is connected with the water inlet pipe.

In a preferred embodiment, in the water flow direction, the inner cavity of the shell is connected with the primary heat exchanger in series, and under the action of the water pump, water in the internal circulation waterway can circulate through the inner cavity of the shell, the primary heat exchanger and the bypass waterway in sequence.

In a preferred embodiment, in the water flow direction, the inner cavity of the shell is connected with the primary heat exchanger in series, and under the action of the water pump, water in the internal circulation waterway can circulate through the primary heat exchanger, the inner cavity of the shell and the bypass waterway in sequence.

In a preferred embodiment, the water pump is arranged on the outlet pipe upstream of the junction of the bypass pipe and the outlet pipe in the direction of flow of the water flow, or the water pump is arranged on the inlet pipe downstream of the junction of the bypass pipe and the inlet pipe in the direction of flow of the water flow.

In a preferred embodiment, the bypass pipe is further provided with a switch valve, and when the water in the internal circulation waterway circulates, the switch valve is in a closed state so as to enable the water in the bypass pipe to circulate; or a three-way valve is arranged at the joint of the water outlet pipe and the bypass pipe, and the three-way valve is used for communicating the water outlet pipe with the bypass pipe when water in the internal circulation waterway circulates; or the junction of the water inlet pipe and the bypass pipe is provided with a three-way valve, and when water in the internal circulation waterway circulates, the bypass pipe is communicated with the water inlet pipe by the three-way valve.

In a preferred embodiment, the three-way valve is a flow-adjustable three-way valve.

In a preferred embodiment, the bypass pipe is provided with an on-off valve which is in an off-state when water is used to flow out of the gas water heating device from the outlet pipe, so that water in the bypass pipe does not circulate.

In a preferred embodiment, the bypass pipe is provided with an electrically operated water valve for regulating the flow of water in the bypass pipe.

In a preferred embodiment, the electric water valve has a first opening degree when the water of the internal circulation waterway circulates, so that the water in the bypass pipe circulates.

In a preferred embodiment, when water is used to flow out of the gas water heating device from the outlet pipe, the electric water valve has a second opening smaller than the first opening, so that water in the bypass pipe does not circulate, or so that water entering the gas water heating device from the inlet pipe partly flows into the bypass pipe and partly flows into the secondary heat exchanger housing interior.

In a preferred embodiment, when water is used to flow out of the gas water heating device from the outlet pipe, the electric water valve has a second opening such that water in the bypass pipe does not circulate, or such that water entering the gas water heating device from the inlet pipe partially flows into the bypass pipe and partially flows into the secondary heat exchanger housing interior.

In a preferred embodiment, a three-way valve is arranged at the connection of the water outlet pipe and the bypass pipe, and the three-way valve comprises a first interface and a second interface which are connected with the water outlet pipe, and a third interface which is connected with the bypass pipe; the first interface is located upstream of the second interface; when water is used for flowing out of the gas water heating device from the water outlet pipe, the first interface is communicated with the second interface; when the water in the internal circulation waterway circulates, the first interface is communicated with the third interface.

In a preferred embodiment, a three-way valve is arranged at the connection of the water inlet pipe and the bypass pipe, and comprises a first interface and a second interface which are connected with the water inlet pipe, and a third interface which is connected with the bypass pipe; the first interface is located upstream of the second interface; when water flows into the gas water heating device from the water inlet pipe, the first interface is communicated with the second interface; when the water in the internal circulation waterway circulates, the second interface is communicated with the third interface.

In a preferred embodiment, the bypass pipe is provided with a one-way valve for allowing water to flow only in one direction from one end of the bypass pipe connected to the outlet pipe to the other end of the bypass pipe connected to the inlet pipe.

In a preferred embodiment, the primary heat exchanger, the fan and the secondary heat exchanger are arranged in sequence along the flow direction of the flue gas, and at least part of the flue gas discharged by the fan can exchange heat with water in the inner cavity of the shell after entering the heat exchange tube.

In a preferred embodiment, the fan is disposed above the primary heat exchanger, and the secondary heat exchanger is disposed obliquely above the primary heat exchanger.

In a preferred embodiment, the ratio of the volume of the heat exchange tube passing through the housing interior to the volume of the housing interior is in the range of 1/3 to 1/2.

In a preferred embodiment, the gas water heating device further comprises a controller, a first temperature sensor for detecting the water temperature entering the inner cavity of the shell, a second temperature sensor for detecting the water temperature flowing out of the primary heat exchanger, and a third temperature sensor for detecting the water temperature between the inner cavity of the shell and the primary heat exchanger, wherein the controller is electrically connected with the first temperature sensor, the second temperature sensor and the third temperature sensor.

In a preferred embodiment, the gas water heating device further comprises a controller and a flow sensor in the internal circulation water path, and the controller is electrically connected with the flow sensor.

In a preferred embodiment, the primary heat exchanger and the inner cavity of the shell are arranged in parallel, and the water flowing into the water inlet pipe enters the primary heat exchanger and the inner cavity of the shell respectively and then flows into the water outlet pipe.

The technical scheme of the utility model has the following remarkable beneficial effects:

According to the gas water heating device provided by the embodiment of the application, the primary heat exchanger and the secondary heat exchanger which are sequentially arranged along the flow direction of the flue gas can ensure that heat in the flue gas is fully absorbed by water in the heat exchanger, so that the gas water heating device is ensured to have higher energy efficiency, and meanwhile, the discharged flue gas is ensured to have lower temperature, so that the purposes of energy conservation and environmental protection are achieved; furthermore, the secondary heat exchanger is arranged in a form of a shell with a preset volume and capable of containing water and a heat exchange tube penetrating through the inner cavity of the shell, wherein the flue gas flowing into the heat exchange tube can exchange heat with the water in the shell, so that the heat exchange efficiency of the secondary heat exchanger and the flue gas can be further improved, the heat in the flue gas can be further absorbed by the water in the heat exchanger, the energy efficiency of the gas water heating device is further improved, and the temperature of the flue gas discharged can be further reduced.

In addition, on the basis of the above, the bypass waterway which is arranged in parallel with the heat exchanger is arranged in the gas water heating device, and by arranging the bypass waterway, the inner cavity of the shell, the primary heat exchanger and the bypass waterway are matched to form an inner circulation waterway, and after the water pump is started, water in the inner circulation waterway can be circulated under the action of the water pump. By utilizing the internal circulation waterway, when the burner is not started, the water temperature in the gas water heating device can be subjected to homogenization treatment, the temperature difference of the water temperature at each position can be controlled in a smaller fluctuation range, and the water temperature is ensured not to be suddenly cooled or suddenly heated when the user uses water again; when the burner is started, the water temperature inside the gas water heating device can be increased to the preset temperature required by a user, so that the hot water with the water temperature meeting the requirements can be used when the user opens the gas water heating device, and the purpose of improving the use experience of the user can be achieved from different angles.

Specific embodiments of the utility model are disclosed in detail below with reference to the following description and drawings, indicating the manner in which the principles of the utility model may be employed. It should be understood that the embodiments of the utility model are not limited in scope thereby. The embodiments of the utility model include many variations, modifications and equivalents within the spirit and scope of the appended claims. Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments in combination with or instead of the features of the other embodiments.

Drawings

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes, proportional sizes, and the like of the respective components in the drawings are merely illustrative for aiding in understanding the present utility model, and are not particularly limited. Those skilled in the art with access to the teachings of the present utility model can select a variety of possible shapes and scale sizes to practice the present utility model as the case may be.

FIG. 1 is a schematic diagram of a gas water heater according to an embodiment of the present application;

FIG. 2 is a schematic diagram showing a water flow direction in an internal circulation waterway of a gas water heater according to an embodiment of the present application;

FIG. 3 is a second schematic diagram of a water flow direction in an internal circulation waterway in a gas water heater according to an embodiment of the present application;

FIG. 4 is a schematic view of another gas water heater according to an embodiment of the present application;

FIG. 5 is a schematic view of a gas water heater according to another embodiment of the present application;

FIG. 6 is a schematic view of a gas water heater according to another embodiment of the present application;

Fig. 7 is a schematic diagram of an application scenario of a gas water heating device according to an embodiment of the present application.

The reference numerals of the application:

1. a burner;

21. A primary heat exchanger;

22. a secondary heat exchanger;

220. A housing;

221. A heat exchange tube;

222. A thermal insulation structure;

23. a connecting pipe;

24. a smoke exhaust pipe;

25. A wind cap;

3. A blower;

4. a water inlet pipe;

5. A water outlet pipe;

6. A bypass pipe;

7. A water pump;

81. a switch valve;

82. A three-way valve;

821. A first interface;

822. a second interface;

823. A third interface;

83. a one-way valve;

84. An electric water valve;

91. a first temperature sensor;

92. a second temperature sensor;

93. a third temperature sensor;

94. and a fourth temperature sensor.

Detailed Description

The technical solution of the present utility model will be described in detail below with reference to the attached drawings and specific embodiments, it should be understood that these embodiments are only for illustrating the present utility model and not for limiting the scope of the present utility model, and various modifications of equivalent forms of the present utility model will fall within the scope of the appended claims after reading the present utility model.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

The utility model provides a gas water heating device which can realize energy conservation and environmental protection and improve comprehensive use experience of users.

Referring to fig. 1 to 6 in combination, in an embodiment of the present application, a gas water heating apparatus is provided, which may include: the main components of the burner 1, the heat exchanger, the fan 3, etc.

The water flowing into the heat exchanger exchanges heat with the flue gas generated by the burner 1 and then flows out of the heat exchanger. The heat exchanger comprises a primary heat exchanger 21 and a secondary heat exchanger 22, and the primary heat exchanger 21 and the secondary heat exchanger 22 are sequentially arranged along the flow direction of the flue gas. The secondary heat exchanger 22 comprises a shell 220 with a preset volume and capable of containing water, and a heat exchange tube 221 penetrating through the inner cavity of the shell 220, wherein the interior of the heat exchange tube 221 is used for circulating flue gas, and the flue gas entering the heat exchange tube 221 exchanges heat with the water contained in the inner cavity of the shell 220 through the heat exchange tube 221. The gas water heating device further comprises a bypass waterway, and the bypass waterway is connected with the heat exchanger in parallel. An internal circulation waterway can be formed in the gas water heating device, the internal circulation waterway is provided with a water pump 7, and the internal circulation waterway comprises an inner cavity of the shell 220, the primary heat exchanger 21 and the bypass waterway; under the action of the water pump 7, water in the internal circulation waterway can circulate.

According to the gas water heating device provided by the embodiment of the application, the primary heat exchanger 21 and the secondary heat exchanger 22 which are sequentially arranged along the flow direction of the flue gas can ensure that heat in the flue gas is fully absorbed by water in the heat exchanger, so that the gas water heating device is ensured to have higher energy efficiency, and meanwhile, the discharged flue gas is ensured to have lower temperature, so that the purposes of energy conservation and environmental protection are achieved; further, by arranging the secondary heat exchanger 22 in a form of a housing 220 having a predetermined volume and capable of containing water and a heat exchange tube 221 passing through an inner cavity of the housing 220, the flue gas flowing into the heat exchange tube 221 can exchange heat with the water in the housing 220, so that the heat exchange efficiency of the secondary heat exchanger 22 and the flue gas can be further improved, the heat in the flue gas can be further absorbed by the water in the heat exchanger, the energy efficiency of the gas water heating device is further improved, and the temperature of the flue gas discharged by the flue gas can be further reduced.

In addition, on the basis of the above, the bypass waterway which is arranged in parallel with the heat exchanger is arranged in the gas water heating device, and by arranging the bypass waterway, the inner cavity of the shell 220, the primary heat exchanger 21 and the bypass waterway are matched to form an internal circulation waterway, and after the water pump 7 is started, the water in the internal circulation waterway can be circulated under the action of the water pump 7. By utilizing the internal circulation waterway, when the combustor 1 is not started, the water temperature in the gas water heater can be subjected to homogenization treatment, the temperature difference of the water temperature at each position can be controlled in a smaller fluctuation range, and the water temperature can not be suddenly cooled or heated when the user uses water again; when the combustor 1 is started, the water temperature inside the gas water heating device can be increased to the preset temperature required by a user, so that hot water with the water temperature meeting the requirement can be used when the user opens the gas water heating device, and the purpose of improving the use experience of the user can be achieved from different angles.

The present application will be described in detail below with reference to specific drawings and embodiments.

In an embodiment of the present application, the gas water heating apparatus mainly includes: a combustor 1, a heat exchanger (a primary heat exchanger 21 and a secondary heat exchanger 22), a fan 3, a water pump 7, a bypass waterway and the like. In addition, the gas water heating device further comprises a water inlet pipe 4 and a water outlet pipe 5 which are communicated with the heat exchanger, water flowing through the water inlet pipe 4 flows into the heat exchanger, exchanges heat with flue gas generated by the combustor 1, and flows out of the heat exchanger and flows into the water outlet pipe 5.

Wherein the heat generated by the combustion of the combustion gas by the burner 1 is used for heating the fluid flowing through the heat exchanger. In particular, the burner 1 may be in the form of a power-adjustable burner.

The heat exchanger is used for circulating water to be heated, and the heat exchanger heats fluid flowing through the heat exchanger through heat generated by burning fuel gas in the burner 1. Typically, the fluid may be water, but it is not excluded that it may also be a mixture of water and steam, or in the form of other fluids. In the following embodiments, the fluid is exemplified by water, and other fluid forms can be analogically referred to, and in particular, the present application will not be described herein.

The heat exchangers may include a primary heat exchanger 21 and a secondary heat exchanger 22. The primary heat exchanger 21 and the secondary heat exchanger 22 are sequentially arranged along the flow direction of the flue gas. Wherein the primary heat exchanger 21 is a heat exchanger relatively closer to a smoke generating source (burner 1) as a main heat exchanger of the gas water heating apparatus. The primary heat exchanger 21 may be in the form of a fin heat exchanger, a plate heat exchanger, a tube heat exchanger, or the like. Of course, the shape, the structure, etc. of the primary heat exchanger 21 may be different according to the actual use situation, and the present application is not limited herein.

The secondary heat exchanger 22 may be arranged downstream of the primary heat exchanger 21 in the flue gas flow direction. Most of the high-temperature flue gas generated by the combustion of the combustor 1 exchanges heat with the primary heat exchanger 21, and then can flow through the secondary heat exchanger 22 to exchange heat with the secondary heat exchanger 22 continuously. In an embodiment of the present application, the secondary heat exchanger 22 may include a hollow housing 220 and heat exchange tubes 221 passing through an inner cavity of the housing 220. The heat exchange tube 221 is used for circulating flue gas, and when the flue gas flows through the heat exchange tube 221, the flue gas can exchange heat with water contained in the inner cavity of the shell 220 efficiently, and the interior space of the gas water heating device is not excessively occupied.

In addition, in the embodiment of the present application, the embodiment that the heat exchange tube 221 of the secondary heat exchanger 22 does not exchange heat with the water contained in the inner cavity of the housing 220 is not excluded, for example, the heat exchange tube 221 is only used to pass through the inner cavity of the housing 220 and is not in contact with the water contained in the inner cavity of the housing 220, or the heat exchange tube 221 may have other matching relationship with the housing 220, and further, the secondary heat exchanger 22 may have other shapes and structures.

The housing 220 of the secondary heat exchanger 22 has a predetermined volume, the interior of the housing 220 contains water, and the volume of the interior of the housing 220 can be about 1L-2L. Further, the ratio of the volume of the heat exchange tube 221 passing through the inner cavity of the housing 220 to the volume of the inner cavity of the housing 220 may be in a range of 1/3 to 1/2, so as to ensure that the water in the volume is fully contacted with the heat exchange tube 221, thereby realizing the secondary full utilization of the energy of the flue gas, ensuring the higher heat exchange efficiency of the flue gas and the water, and simultaneously, not occupying too much space inside the gas water heating device and affecting the volume of the gas water heating device by reasonably controlling the volume and the ratio of the heat exchange tube 221 and the inner cavity of the housing 220.

The housing 220 may have a hollow water tank structure, and the specific shape and structure of the housing 220 may be adaptively set according to the space inside the gas water heater, etc., which is not particularly limited herein. The heat exchanging pipe 221 may be in the form of a circular smoke pipe having a certain diameter, and it is needless to say that other shapes and configurations of the heat exchanging pipe 221 are not excluded, and the present application is not limited thereto.

The inner cavity of the shell 220 is communicated with the primary heat exchanger 21, and the heated water in the inner cavity of the shell 220 and the primary heat exchanger 21 can be output to a user. Specifically, in the water flow direction, the inner cavity of the housing 220 may be disposed in series or parallel with the primary heat exchanger 21.

The gas water heating device can further comprise a bypass waterway, and the bypass waterway is arranged in parallel with the heat exchanger. Specifically, the bypass waterway may be in the form of the bypass pipe 6, but of course, the bypass waterway may be an internal flow channel formed in the waterway module, or the bypass waterway may be in other forms. In particular, the form of the bypass waterway is not limited solely herein.

In the embodiment of the application, an internal circulation waterway can be formed in the gas water heating device, and the internal circulation waterway comprises an inner cavity of the shell 220, the primary heat exchanger 21 and the bypass waterway. The internal circulation waterway is provided with a water pump 7, the water pump 7 is used for providing driving force for water flow, and water in the internal circulation waterway can circulate under the action of the water pump 7. The water pump 7 may be a water pump 7 existing in a gas water heater, or may be provided separately.

For the internal circulation waterway including the form of the inner cavity of the shell 220, the primary heat exchanger 21 and the bypass waterway, two ends of the bypass waterway can be respectively connected to two ends of the heat exchanger to form a waterway closed loop.

Further, for the gas water heater, the gas water heater may include a water inlet pipe 4 and a water outlet pipe 5, which are communicated with the heat exchanger, water flowing through the water inlet pipe 4 flows into the heat exchanger, exchanges heat with flue gas generated by the burner 1, and flows out of the heat exchanger and flows into the water outlet pipe 5.

Wherein the inlet pipe 4 may be in communication with an external water source for supplying water to be heated to the gas water heating device. The water outlet pipe 5 can be communicated with a water terminal of a user so as to provide the water heated by the gas water heating device to the water terminal. Furthermore, as shown in fig. 6, for a gas water heating device with zero cold water function, the water inlet pipe 4 and the water outlet pipe 5 can be used as components of the whole zero cold water circulation. In an embodiment of the application, the part of the inlet pipe 4 and the part of the outlet pipe 5 may be part of an internal circulation.

In the present embodiment, the bypass waterway including the bypass pipe 6 is mainly exemplified. One end of the bypass pipe 6 may be connected to the outlet pipe 5 and the other end of the bypass pipe 6 may be connected to the inlet pipe 4.

An internal circulation waterway can be formed in the gas water heating device, and the internal circulation waterway can comprise an inner cavity of the shell 220, the primary heat exchanger 21, a part of water outlet pipe 5, the bypass waterway and a part of water inlet pipe 4; under the action of the water pump 7, water in the internal circulation waterway can circulate.

As shown in fig. 2, in some embodiments, in the water flow direction, the inner cavity of the casing 220 is connected in series with the primary heat exchanger 21, and under the action of the water pump 7, water in the internal circulation waterway can circulate through the inner cavity of the casing 220, the primary heat exchanger 21 and the bypass waterway in sequence.

In these embodiments, taking the water flow direction as anticlockwise in fig. 2 as an example, when the water pump 7 is started, the water flows through the primary heat exchanger 21, part of the water outlet pipe 5, the bypass pipe 6, part of the water inlet pipe 4 and the inner cavity of the shell 220 in sequence, and returns to the primary heat exchanger 21 to form an internal circulation waterway.

Or as shown in fig. 3, in the water flow direction, the inner cavity of the shell 220 is connected with the primary heat exchanger 21 in series, and under the action of the water pump 7, the water in the internal circulation waterway can circulate through the primary heat exchanger 21, the inner cavity of the shell 220 and the bypass waterway in sequence.

In these embodiments, taking the water flow direction as clockwise in fig. 3 as an example, when the water pump 7 is started, the water flows through the primary heat exchanger 21, the inner cavity of the housing 220, part of the water inlet pipe 4, the bypass waterway, part of the water outlet pipe 5 in sequence, and returns to the primary heat exchanger 21.

Or in other embodiments, the primary heat exchanger 21 and the inner cavity of the housing 220 are arranged in parallel, and the water flowing into the water inlet pipe 4 enters the primary heat exchanger 21 and the inner cavity of the housing 220, and then flows into the water outlet pipe 5.

In some embodiments, the water pump 7 may be provided on the outlet pipe 5 upstream of the junction of the bypass pipe 6 and the outlet pipe 5 in the direction of flow of the water, as shown in fig. 3, or the water pump 7 may be provided on the inlet pipe 4 downstream of the junction of the bypass pipe 6 and the inlet pipe 4 in the direction of flow of the water, as shown in fig. 2.

When the water pump 7 is disposed at the above-described position, the water pump 7 may provide a driving force for the water of the internal circulation waterway. In addition, the water pump 7 can also provide driving force for water in the external circulation waterway, and the water pump 7 can also provide driving force for water flow in the normal water use state of a user.

In the embodiment of the application, the on-off of the internal circulation waterway can be controlled by arranging a valve element.

As shown in fig. 1, in some embodiments, the bypass pipe 6 may further be provided with an on-off valve 81, and when the water in the internal circulation water path circulates, the on-off valve 81 is in a closed state, so that the water in the bypass pipe 6 circulates. When water is used to flow out of the gas water heating device from the outlet pipe 5, i.e. when a user has a water demand, the on-off valve 81 is in an off state so that the water in the bypass pipe 6 does not circulate.

Or as shown in fig. 2, a three-way valve 82 is arranged at the joint of the water outlet pipe 5 and the bypass pipe 6, and the three-way valve 82 communicates the water outlet pipe 5 with the bypass pipe 6 when the water in the internal circulation waterway circulates.

In a specific embodiment, a three-way valve 82 is arranged at the connection position of the water outlet pipe 5 and the bypass pipe 6, and the three-way valve 82 comprises a first interface 821 and a second interface 822 connected with the water outlet pipe 5, and a third interface 823 connected with the bypass pipe 6; the first interface 821 is located upstream of the second interface 822; when water is used to flow out of the gas water heating device from the outlet pipe 5, the first interface 821 and the second interface 822 are communicated; when the water of the internal circulation waterway circulates, the first interface 821 and the third interface 823 are communicated.

Or as shown in fig. 4, a three-way valve 82 is arranged at the joint of the water inlet pipe 4 and the bypass pipe 6, and the three-way valve 82 communicates the bypass pipe 6 with the water inlet pipe 4 when the water in the internal circulation waterway circulates.

In a specific embodiment, a three-way valve 82 is arranged at the connection of the water inlet pipe 4 and the bypass pipe 6, and the three-way valve 82 comprises a first interface 821 and a second interface 822 connected with the water inlet pipe 4, and a third interface 823 connected with the bypass pipe 6; the first interface 821 is located upstream of the second interface 822; when water is used to flow from the inlet pipe 4 into the gas water heating device, the first interface 821 and the second interface 822 are communicated; when the water of the internal circulation waterway circulates, the second interface 822 and the third interface 823 are communicated.

Referring to fig. 5, when the valve element of the internal circulation water path is in the form of a three-way valve 82, the three-way valve 82 may be specifically a flow-adjustable three-way valve 82.

When the valve element is the flow-adjustable three-way valve 82, the flow-adjustable three-way valve 82 can be utilized to mix hot water flowing out of the heat exchanger and cold water flowing in of the bypass pipe 6 in a proper proportion, so that water meeting the preset temperature requirement is directly output to a user, the phenomenon that the output temperature of water which is heated again after being heated by an internal circulation waterway is too high, more cold water is needed to be mixed in a water terminal later, the mixed cold water amount is uncertain, and particularly the phenomenon that the output temperature is unstable is easily caused when the user uses water at multiple points is avoided.

Referring to fig. 5, in some embodiments, the bypass pipe 6 is provided with an electrically operated water valve 84 for regulating the flow of water in the bypass pipe 6.

In the present embodiment, the electric water valve 84 is provided in the bypass pipe 6, so that the amount of water flow in the bypass pipe 6 can be adjusted. The electrically operated water valve 84 may be in the form of an electrically operated valve capable of stepless adjustment of the flow. The electric water valve 84 may be electrically connected to a controller, and the opening degree of the electric water valve 84 is adjusted according to a control signal of the controller, thereby realizing the flow adjustment of the water in the bypass pipe 6. Specifically, the specific form, shape, configuration, etc. of the electrically operated water valve 84 is not particularly limited herein.

For example, when the water in the internal circulation water path circulates, the electric water valve 84 has a first opening degree so that the water in the bypass pipe 6 circulates.

When the water of the internal circulation waterway circulates, since the bypass pipe 6 forms a part of the internal circulation waterway, water having a predetermined flow rate may flow through the bypass pipe 6. Wherein the flow rate of the water flowing through the bypass pipe 6 can be made to reach a predetermined flow rate by controlling the opening degree of the electric water valve 84. The first opening degree may be specifically a maximum opening degree of the electric water valve 84, or may be a certain intermediate opening degree of the electric water valve 84 between the maximum opening degree and the minimum opening degree (in this case, the electric water valve 84 is in a completely closed non-overcurrent state). Specifically, the value of the first opening is not specifically limited herein.

When water is used to flow out of the gas water heater from the outlet pipe 5, the electric water valve 84 has a second opening smaller than the first opening, so that water in the bypass pipe 6 does not circulate, or so that water entering the gas water heater from the inlet pipe 4 partially flows into the bypass pipe 6 and partially flows into the inner cavity of the housing 220 of the secondary heat exchanger 22.

When water in the gas water heater flows out of the outlet pipe 5, the electric water valve 84 has a second opening, which may be a smaller opening. Specifically, the second opening may be smaller than the first opening. For example, when the second opening is the minimum opening of the electric water valve 84 (when the electric water valve 84 is in a completely closed non-overflow state), the water in the bypass pipe 6 does not flow; or the second opening degree can be a smaller opening degree value, so that a larger pipe resistance is generated in the bypass pipe 6, and water entering the gas water heating device from the water inlet pipe 4 flows into the bypass pipe 6 partially and flows into the inner cavity of the shell 220 of the secondary heat exchanger 22 partially.

As shown in fig. 6, a second temperature sensor 92 may be provided on the outlet pipe 5 of the gas water heating device and upstream of the connection position of the bypass pipe 6 and the outlet pipe 5, and a fourth temperature sensor 94 may be provided on the outlet pipe 5 and downstream of the connection position of the bypass pipe 6 and the outlet pipe 5. The second temperature sensor 92 and the fourth temperature sensor 94 may each be electrically connected to a controller. Wherein, the controller can store the target water outlet temperature set by the user.

When water in the gas water heater flows out from the water outlet pipe 5, the opening degree of the electric water valve 84 can be specifically determined based on the water temperature detected by the second temperature sensor 92 and the target water outlet temperature set by the user. In addition, the water outlet temperature signal detected by the fourth temperature sensor 94 may be used to determine whether the water supplied to the user has reached the target water outlet temperature, and if the target water outlet temperature has not been reached, parameters such as the opening of the electric water valve 84, the combustion load, etc. may be adjusted.

Referring to fig. 7 in combination, when the external supply of tap water is constant, cold water needs to be simultaneously output to different user terminals when the user uses water at multiple points, and meanwhile, the cold water needs to be provided to the gas water heating device, when the output of hot water with stable temperature at the gas water heating device side is ensured by the flow-adjustable three-way valve 82, the cold water amount needed to be doped at each user terminal can be greatly reduced, and the fluctuation of the doped cold water amount is also in a smaller controllable range, so that the stable water outlet temperature of the water terminal can be ensured.

As shown in fig. 3, further, the bypass pipe 6 may be provided with a check valve 83, and the check valve 83 is configured to enable water to flow only in one direction from one end of the bypass pipe 6 connected to the water outlet pipe 5 to the other end of the bypass pipe 6 connected to the water inlet pipe 4, so that external cold water can be prevented from entering the internal circulation waterway through the bypass pipe 6 during the internal circulation process.

As shown in fig. 2, or fig. 3 or fig. 4, in some embodiments, the secondary heat exchanger 22 further has a heat insulation structure 222, and the heat insulation structure 222 is used to insulate the inner cavity of the housing 220. By providing the thermal insulation structure 222, water in the interior cavity of the housing 220 can be insulated.

In a specific embodiment, the insulating structure 222 may be an insulating layer surrounding the exterior of the housing 220. When the thermal insulation structure 222 is in the form of a thermal insulation layer, the thermal insulation layer may be disposed around the outer surface of the housing 220, and the thermal insulation layer may be made of a thermal insulation material resistant to high temperature, such as thermal insulation cotton, where the specific material of the thermal insulation layer is not limited herein.

In another specific embodiment, the insulating structure 222 may be a cavity provided outside the housing 220, and the cavity may be formed by a space provided between a jacket provided outside the housing 220 and the housing 220.

When the insulation structure 222 is in the form of a cavity, the insulation structure 222 may include a casing disposed outside the housing 220, a gap is formed between the casing and the housing 220 after the casing is disposed outside the housing 220, and the insulation structure 222 is formed by using the gap between the casing and the housing 220 to insulate the housing 220 and water therein. When the heat insulation structure 222 is in the form of the above-mentioned sleeved relation with the casing 220, a cavity is formed between the outside of the casing 220 and the shell, the cavity outside the casing 220 may be communicated with the heat exchange tube 221, the flue gas flowing out of the heat exchange tube 221 flows into the cavity outside the casing 220, and then is discharged outwards through the smoke exhaust tube 24, so that on one hand, the casing 220 and water in the casing 220 may be insulated, and on the other hand, the heat exchange efficiency between the secondary heat exchanger 22 and the flue gas may be further improved, so that the waste heat in the flue gas may be utilized maximally.

The fan 3 is used for providing driving force for airflow. Specifically, the structure of the fan 3 itself, and the arrangement position and arrangement manner thereof may be different according to the actual usage scenario, and the present application is not limited herein. For example, the fan 3 may specifically be a variable frequency fan 3. The rotational speed of the blower 3 may be adaptively changed according to a change in conditions such as a combustion load.

In some embodiments, the primary heat exchanger 21, the fan 3, and the secondary heat exchanger 22 are sequentially disposed along the flow direction of the flue gas, and at least a portion of the flue gas exhausted from the fan 3 can exchange heat with water in the inner cavity of the housing 220 after entering the heat exchange tube 221.

Specifically, the fan 3 may be provided with an air inlet and an air outlet, wherein the air inlet may be opposite to the primary heat exchanger 21, and the air outlet may be communicated with the heat exchange tube 221 of the secondary heat exchanger 22. On the flow direction along the flue gas, the primary heat exchanger 21, the fan 3 and the secondary heat exchanger 22 are sequentially arranged, the flue gas generated by the combustion of the combustor 1 can exchange heat with the primary heat exchanger 21, the flue gas after exchanging heat with the primary heat exchanger 21 enters the fan 3, then enters the heat exchange tube 221 of the secondary heat exchanger 22 to exchange heat with water in the shell 220, and finally is discharged outwards through the smoke exhaust tube 24, so that the gas water heating device is guaranteed to have higher heat exchange efficiency, and ideal energy-saving and environment-friendly effects are achieved.

Further, the fan 3 is disposed above the primary heat exchanger 21, and the secondary heat exchanger 22 is disposed obliquely above the primary heat exchanger 21.

In this embodiment, the gas water heating device may specifically be an updraft gas water heating device. The gas water heating device is provided with a shell, and the combustor 1, the primary heat exchanger 21 and the fan 3 are sequentially arranged in the shell along the height direction. An opening for mounting a smoke vent is provided at the top of the housing. In summary, the above-mentioned combustor 1, the primary heat exchanger 21, the mounted position of fan 3, and the relative setting mode of air intake, the air exit of fan 3 and along the flow direction of flue gas, this primary heat exchanger 21, fan 3, the relation of setting of secondary heat exchanger 22, can set up primary heat exchanger 21 in the oblique top of this secondary heat exchanger 22, be close to the position that above-mentioned set up the exhaust port, on the one hand can effectively utilize the inside limited space of this gas water heater shell, on the other hand, this fan 3, primary heat exchanger 21, the arrangement of secondary heat exchanger 22 is also rationally set up according to the flow direction of flue gas ground, be favorable to high-efficient heat transfer between flue gas and the heat exchanger.

In some embodiments, the gas water heating device may further include a controller, and a first temperature sensor 91 for detecting a water temperature entering the inner cavity of the housing 220, a second temperature sensor 92 for detecting a water temperature exiting the primary heat exchanger 21, and a third temperature sensor 93 for detecting a water temperature between the inner cavity of the housing 220 and the primary heat exchanger 21, wherein the controller is electrically connected to the first temperature sensor 91, the second temperature sensor 92, and the third temperature sensor 93.

In this embodiment, in order to obtain the temperature and temperature difference of the water in the internal circulation waterway, a temperature sensor electrically connected to the controller may be provided, and the controller may determine the temperature and temperature difference of the water in the internal circulation waterway according to the temperature signal obtained by the temperature sensor.

Specifically, the temperature sensor may include: a first temperature sensor 91 for detecting the water temperature entering the inner cavity of the shell 220, a second temperature sensor 92 for detecting the water temperature exiting the primary heat exchanger 21, and a third temperature sensor 93 for detecting the water temperature between the inner cavity of the shell 220 and the primary heat exchanger 21.

The first temperature sensor 91 may be disposed on the water inlet pipe 4, for example, at a position where the water inlet pipe 4 is connected to the bypass pipe 6, the second temperature sensor 92 may be disposed on the connection pipe 23 between the inner cavity of the housing 220 and the primary heat exchanger 21, and the third temperature sensor 93 may be disposed on the water outlet pipe 5, for example, at a position where the water outlet pipe 5 is connected to the bypass pipe 6.

Of course, the number and positions of the temperature sensors are not limited to the above description, and other modifications may be made by those skilled in the art in light of the technical spirit of the present application, but all the functions and effects achieved are the same or similar to those of the present application, and are included in the protection scope of the present application.

In some embodiments, the gas water heating device may further include a controller, and a flow sensor in the internal circulation waterway, the controller being electrically connected to the flow sensor.

In this embodiment, in order to obtain the flow condition in the internal circulation waterway, a flow sensor may be provided, and the flow sensor is electrically connected to a controller, and the controller may determine the flow condition in the internal circulation waterway according to the flow signal obtained by the flow sensor.

When the internal circulation waterway is established in the gas water heating device and the internal circulation state can be entered, the gas water heating device can solve different technical problems in different scenes.

For example, in a first scenario, for a scenario in which a water spot is close to a gas water heating device, such as a kitchen, for example, a user wishes to turn on the gas water heating device when water is needed, and then immediately have a water output that meets a preset temperature requirement.

The gas water heating device provided by the application has a kitchen water mode, and the kitchen water mode can be equivalent to the gas water heating device which has a preheating function on water in an internal circulation waterway.

The water pump 7 is started to form an internal circulation water path in the kitchen water mode, and after the burner 1 is started, the water in the internal circulation state can be heated to a preset temperature. When the user needs water, the water consumption point is opened, and the water meeting the temperature requirement can be output to the user.

Considering that the kitchen water is commonly used in a short time and a small amount, after the preheating step of the kitchen water mode is completed, the water reaching the preset temperature in the internal circulation waterway can meet the requirement of a user on hot water with a certain water quantity. In particular, the gas water heating device provided in the embodiment of the application is provided with the secondary heat exchanger 22, the secondary heat exchanger 22 is provided with the shell 220 with a preset volume, the heat exchange pipe 221 penetrates through the shell 220, and the water in the shell 220 also reaches the preset temperature after the preheating step is completed. Compared with the existing gas water heating device, the gas water heating device provided by the application has larger water supply quantity, and after the gas water heating device finishes preheating, more hot water quantity can be provided for a user, so that the requirement of a small amount of water for a short time can be met before the burner 1 is not started, and further the burner 1 is prevented from being started to burn by frequent ignition of the gas water heating device, thus the service life of the gas water heating device is prolonged, the problems of more concentrated noise and heating position caused by frequent starting of the gas water heating device, uneven heating water temperature and the like are avoided, and the comprehensive use experience of the user is improved. In addition, as the heat exchange pipe 221 passes through the shell 220 to exchange heat with the water in the shell 220, the heat exchange efficiency of the secondary heat exchanger 22 and the flue gas can be further improved, so that the heat in the flue gas can be further absorbed by the water in the heat exchanger, namely, the energy efficiency of the gas water heating device is further improved, and the purposes of energy conservation and environmental protection are achieved.

After the preheating step of the kitchen water mode is completed, the user may need to use water, and it should be noted that the water use position of the user may be in a kitchen near the installation position of the gas water heating device, or may be in other positions, such as a balcony, a bathroom, and the like. When the user is using water, if it is detected that the water outlet temperature is lowered by a predetermined temperature on the basis of the preset temperature, or the difference of the water outlet temperatures reaches a predetermined temperature difference, the burner 1 may be started to perform ignition heating.

For example, in the second scenario, the gas water heater is in a normal water use mode, and when a user uses water, the burner 1 in the gas water heater will normally start burning.

If the user pauses the water in the water consumption process, the internal circulation can be started at this time, at least the water pump 7 enters a working state, and the water in the internal circulation waterway is circulated, so that the water temperature in the internal circulation waterway is uniform.

When the water terminal is opened again for water consumption by the subsequent user, the water temperature in the internal circulation waterway is uniform, so that the user can not be suddenly cooled or heated in the earlier stage when continuing to use the water. In addition, after the water temperature in the internal circulation waterway reaches a stable and uniform state, if the water temperature in the internal circulation waterway is detected to be lower in the process of suspending water by a user, the burner 1 can be started to heat the water in the internal circulation waterway so as to reach the preset temperature. Of course, during the inner cycle, if the signal for the user to turn on the hot water is again acquired, the inner cycle may be exited.

It should be noted that, in the description of the present application, the terms "first," "second," and the like are used for descriptive purposes only and to distinguish between similar objects, and there is no order of preference between them, nor should they be construed as indicating or implying relative importance. Furthermore, in the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.

The foregoing embodiments in the present specification are all described in a progressive manner, and the same and similar parts of the embodiments are mutually referred to, and each embodiment is mainly described in a different manner from other embodiments.

The foregoing is merely a few embodiments of the present utility model, and the embodiments disclosed in the present utility model are merely examples which are used for the convenience of understanding the present utility model and are not intended to limit the present utility model. Any person skilled in the art can make any modification and variation in form and detail of the embodiments without departing from the spirit and scope of the present disclosure, but the scope of the present disclosure is still subject to the scope of the appended claims.

Claims

1. A gas water heating device, characterized in that it comprises: the device comprises a combustor, a heat exchanger and a fan, wherein water flowing into the heat exchanger exchanges heat with flue gas generated by the combustor and then flows out of the heat exchanger;

2. A gas water heating apparatus as claimed in claim 1, wherein the secondary heat exchanger further has a heat retaining structure for retaining heat within the housing interior.

3. The gas water heating apparatus as claimed in claim 2, wherein the heat-insulating structure is a heat-insulating layer enclosed outside the housing.

4. A gas water heating apparatus according to claim 2, wherein the insulating structure is a cavity provided outside the housing, the cavity being constituted by a void provided between a jacket provided outside the housing and the housing.

5. A gas water heating apparatus according to claim 4, wherein the cavity outside the housing is in communication with the heat exchange tube, and flue gas exiting the heat exchange tube flows into the cavity outside the housing.

6. A gas water heating apparatus according to claim 1, wherein the housing cavity and the primary heat exchanger are arranged in series or parallel in the water flow direction.

7. The gas water heating device according to claim 1, further comprising a water inlet pipe and a water outlet pipe which are communicated with the heat exchanger, wherein water flowing through the water inlet pipe flows into the heat exchanger, exchanges heat with flue gas generated by the burner, flows out of the heat exchanger and flows into the water outlet pipe; the bypass waterway comprises a bypass pipe, one end of the bypass pipe is connected with the water outlet pipe, and the other end of the bypass pipe is connected with the water inlet pipe.

8. A gas water heating apparatus according to claim 6, wherein the housing cavity and the primary heat exchanger are connected in series in the water flow direction,

Under the action of the water pump, water in the internal circulation waterway can sequentially pass through the inner cavity of the shell, the primary heat exchanger and the bypass waterway for circulation.

9. A gas water heating apparatus according to claim 6, wherein the housing cavity and the primary heat exchanger are connected in series in the water flow direction,

Under the action of the water pump, the water in the internal circulation waterway can sequentially pass through the primary heat exchanger, the inner cavity of the shell and the bypass waterway for circulation.

10. A gas water heating apparatus according to claim 7, wherein,

The water pump is arranged on the water outlet pipe and is positioned at the upstream of the joint of the bypass pipe and the water outlet pipe along the flow direction of water flow,

Or alternatively

The water pump is arranged on the water inlet pipe and is positioned at the downstream of the joint of the bypass pipe and the water inlet pipe along the flowing direction of water flow.

11. A gas water heating apparatus according to claim 7, wherein,

The bypass pipe is also provided with a switch valve, and when the water in the internal circulation waterway circulates, the switch valve is in a closed state so that the water in the bypass pipe circulates;

Or a three-way valve is arranged at the joint of the water outlet pipe and the bypass pipe, and the three-way valve is used for communicating the water outlet pipe with the bypass pipe when water in the internal circulation waterway circulates;

Or the junction of the water inlet pipe and the bypass pipe is provided with a three-way valve, and when water in the internal circulation waterway circulates, the bypass pipe is communicated with the water inlet pipe by the three-way valve.

12. The gas water heating apparatus as claimed in claim 11, wherein the three-way valve is a flow-adjustable three-way valve.

13. A gas water heating apparatus according to claim 11, wherein the bypass pipe is provided with an on-off valve which is in an off-state when water is used to flow out of the gas water heating apparatus from the outlet pipe, so that water in the bypass pipe does not circulate.

14. A gas water heating apparatus as claimed in claim 10, wherein the bypass pipe is provided with an electrically operated water valve for regulating the flow of water in the bypass pipe.

15. A gas water heating apparatus according to claim 14, wherein the electric water valve has a first opening when water in the internal circulation water path circulates, so that water in the bypass pipe circulates.

16. A gas water heating apparatus according to claim 15, wherein when water is used to flow out of the gas water heating apparatus from the outlet pipe, the electric water valve has a second opening smaller than the first opening, so that water in the bypass pipe does not circulate, or so that water entering the gas water heating apparatus from the inlet pipe partially flows into the bypass pipe and partially flows into the secondary heat exchanger housing interior.

17. A gas water heating apparatus according to claim 15, wherein when water is used to flow out of the gas water heating apparatus from the outlet pipe, the electrically operated water valve has a second opening such that water in the bypass pipe is not circulated, or such that water entering the gas water heating apparatus from the inlet pipe partially flows into the bypass pipe and partially flows into the secondary heat exchanger housing interior.

18. The gas water heating device according to claim 11, wherein a three-way valve is arranged at the connection of the water outlet pipe and the bypass pipe, and comprises a first interface and a second interface connected with the water outlet pipe, and a third interface connected with the bypass pipe; the first interface is located upstream of the second interface;

When water is used for flowing out of the gas water heating device from the water outlet pipe, the first interface is communicated with the second interface; when the water in the internal circulation waterway circulates, the first interface is communicated with the third interface.

19. The gas water heating device according to claim 11, wherein a three-way valve is provided at the junction of the inlet pipe and the bypass pipe, the three-way valve comprising a first port and a second port connected to the inlet pipe, and a third port connected to the bypass pipe; the first interface is located upstream of the second interface;

When water flows into the gas water heating device from the water inlet pipe, the first interface is communicated with the second interface; when the water in the internal circulation waterway circulates, the second interface is communicated with the third interface.

20. A gas water heating apparatus according to claim 11, wherein the bypass pipe is provided with a one-way valve for allowing water to flow only in one direction from one end of the bypass pipe connected to the outlet pipe to the other end of the bypass pipe connected to the inlet pipe.

21. The gas water heating device according to claim 1, wherein the primary heat exchanger, the fan and the secondary heat exchanger are arranged in sequence along the flow direction of the flue gas, and at least part of the flue gas discharged by the fan can exchange heat with water in the inner cavity of the shell after entering the heat exchange tube.

22. A gas water heating apparatus according to claim 21, wherein the fan is disposed above the primary heat exchanger and the secondary heat exchanger is disposed obliquely above the primary heat exchanger.

23. A gas water heating apparatus according to claim 1, wherein,

The ratio of the volume of the heat exchange tube penetrating through the inner cavity of the shell to the volume of the inner cavity of the shell is 1/3 to 1/2.

24. A gas water heating apparatus according to any one of claims 7-9, further comprising a controller, a first temperature sensor for detecting water temperature entering the housing interior, a second temperature sensor for detecting water temperature exiting the primary heat exchanger, a third temperature sensor for detecting water temperature between the housing interior and the primary heat exchanger, the controller being electrically connected to the first temperature sensor, the second temperature sensor and the third temperature sensor.

25. A gas water heating apparatus according to any one of claims 7 to 9, further comprising a controller and a flow sensor in the internal circulation water circuit, the controller being electrically connected to the flow sensor.

26. A gas water heating device according to claim 6, wherein the primary heat exchanger and the inner cavity of the shell are arranged in parallel, the gas water heating device further comprises a water inlet pipe and a water outlet pipe which are communicated with the heat exchanger,

And the water flowing in the water inlet pipe enters the primary heat exchanger and the inner cavity of the shell respectively and then flows into the water outlet pipe.