CN221464014U - Gas water heater - Google Patents

Abstract

The utility model discloses a gas water heating device, which comprises: the first heat exchanger is communicated with the second heat exchanger, and water flowing out of the inner cavity of the shell flows into the first heat exchanger; the gas water heater is internally provided with a communication pipeline which can be used for communicating the outlet of the first heat exchanger with the water inlet of the second heat exchanger, and the communication pipeline can be used for refluxing water flowing out of the first heat exchanger to the second heat exchanger; the inner cavity of the shell, the heat exchanger and the pipeline can form an internal circulation 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 used as a typical instant water heater and mainly comprises a fan, a combustion device, 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 first heat exchanger and the second heat exchanger are sequentially arranged along the flow direction of the flue gas generated by the combustion device; the second heat exchanger comprises a shell with a preset volume and capable of containing water and a heat exchange pipeline penetrating through the inner cavity of the shell, the interior of the heat exchange pipeline is used for circulating smoke, and the smoke exchanges heat with the water contained in the inner cavity of the shell through the heat exchange pipeline; the first heat exchanger is communicated with the second heat exchanger, and water flowing out of the inner cavity of the shell of the second heat exchanger flows into the first heat exchanger; the gas water heating device is internally provided with a communication pipeline which can be used for communicating the outlet of the first heat exchanger with the water inlet of the second heat exchanger, and the communication pipeline can be used for refluxing water flowing out of the first heat exchanger to the second heat exchanger; the shell inner cavity of the second heat exchanger, the first heat exchanger and the communication pipeline can form an internal circulation waterway.

In a preferred embodiment, the gas water heating device further comprises a driving device arranged on the internal circulation water path, and the driving device can drive water in the internal circulation water path to sequentially circulate along the inner cavity of the shell of the second heat exchanger, the first heat exchanger and the communication pipeline.

In a preferred embodiment, the second heat exchanger further comprises a drain, the water inlet and drain communicating with the housing interior cavity; the first heat exchanger further comprises an inlet and a heat exchange tube, the heat exchange tube is communicated with the inlet and the outlet, and the water outlet is connected with the inlet so that water flowing out of the second heat exchanger flows into the first heat exchanger.

In a preferred embodiment, the communication line is capable of communicating the outlet with the water inlet to return water exiting the first heat exchanger outlet to the second heat exchanger housing interior.

In a preferred embodiment, the drive means comprises a water pump.

In a preferred embodiment, the gas water heating device further comprises a water inlet pipe communicated with the water inlet of the second heat exchanger, a water outlet pipe communicated with the outlet of the first heat exchanger, and both the water inlet pipe and the water outlet pipe are communicated with the communicating pipe; the water pump is arranged on the water outlet pipe and is positioned at the upstream of the joint of the communication pipeline and the water outlet pipe in the water flow direction, or the water pump is arranged on the water inlet pipe and is positioned at the downstream of the joint of the communication pipeline and the water inlet pipe in the water flow direction.

In a preferred embodiment, the communicating pipe is further provided with a switching valve, and when the water in the internal circulation waterway circulates, the switching valve is in an opened state so that the water in the communicating pipe circulates; or a three-way valve is arranged at the joint of the water outlet pipe and the communication pipeline, and the three-way valve communicates the water outlet pipe with the communication pipeline when water in the internal circulation waterway circulates; or the junction of inlet tube with the intercommunication pipeline is provided with the three-way valve, when the water of inner loop water route circulates, the three-way valve will the intercommunication pipeline with the inlet tube intercommunication.

In a preferred embodiment, the communication 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 water outlet pipe, so that the water in the communication pipe does not circulate.

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

In a preferred embodiment, the electric water valve has a first opening degree when the water of the internal circulation water path circulates, so that the water in the communication pipe is circulated.

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 communication line does not circulate, or so that water entering the gas water heating device from the inlet pipe partly flows into the communication line and partly flows into the second heat exchanger housing cavity.

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 communication line does not circulate, or such that water entering the gas water heating device from the inlet pipe partially flows into the communication line and partially flows into the second heat exchanger housing interior.

In a preferred embodiment, a three-way valve is arranged at the connection part of the water outlet pipe and the communication pipeline, 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 communication pipeline; 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 part of the water inlet pipe and the communication pipeline, and the three-way valve 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 communication pipeline; 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 communication pipe is provided with a check valve for allowing water to flow only in one direction from one end of the communication pipe connected to the water outlet pipe to the other end of the communication pipe connected to the water inlet pipe.

In a preferred embodiment, the gas water heating device further comprises a fan, and after the fan is started, the flue gas generated by combustion of the combustion device can be driven to flow to the first heat exchanger and the second heat exchanger in sequence.

In a preferred embodiment, the fan is disposed between the first heat exchanger and the second heat exchanger, an air inlet of the fan is located downstream of the first heat exchanger along a flue gas flow direction, and an air outlet of the fan is located upstream of the second heat exchanger along the flue gas flow direction and is communicated with an inner cavity of a heat exchange pipeline of the second heat exchanger.

In a preferred embodiment, the volume of the housing interior is in the range of: 1 liter to 2 liters.

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

In a preferred embodiment, the heat exchange tube passing through the housing cavity of the second heat exchanger is a stainless steel heat exchange tube.

In a preferred embodiment, the housing is a stainless steel housing and the first heat exchanger is a stainless steel heat exchanger.

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 first heat exchanger and the second 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 first heat exchanger and the second 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 second 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 second 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 application is provided with the communication pipeline which can communicate the outlet of the first heat exchanger and the water inlet of the second heat exchanger, and by arranging the communication pipeline, the inner cavity of the second heat exchanger shell, the first heat exchanger and the communication pipeline are matched to form an internal circulation waterway, and after the driving device (such as a water pump) is started, the water in the internal circulation waterway can be circulated under the action of the water pump. When the combustion device is not started, the internal circulation waterway can homogenize the water temperature in the gas water heating device, the water temperature difference 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 starting combustion apparatus, can promote the inside temperature of gas water heater to the required preset temperature of user to can use the hot water that the water temperature satisfies the demand when the user opens gas water heater, and then reach the purpose that promotes user's use experience 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 combustion device;

21. A first heat exchanger;

211. An inlet;

212. An outlet;

22. a second heat exchanger;

220. A housing;

2201. A water inlet; 2202. a water outlet;

221. a heat exchange pipeline;

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 communication pipeline;

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 combustion device 1, the first heat exchanger 21, the second heat exchanger 22, and the like.

The first heat exchanger 21 and the second heat exchanger 22 are sequentially arranged along the flow direction of the flue gas. The first heat exchanger 21 is communicated with the second heat exchanger 22, and water flowing out of the inner cavity of the shell 220 of the second heat exchanger 22 flows into the first heat exchanger 21. The second heat exchanger 22 comprises a shell 220 with a preset volume and capable of containing water, and a heat exchange pipeline 221 penetrating through the inner cavity of the shell 220, wherein the interior of the heat exchange pipeline 221 is used for circulating flue gas, and the flue gas entering the heat exchange pipeline 221 exchanges heat with the water contained in the inner cavity of the shell 220 through the heat exchange pipeline 221. The gas water heater further comprises a communication pipeline 6, and the communication pipeline 6 communicates the outlet 212 of the first heat exchanger 21 with the water inlet 2201 of the second heat exchanger 22, so that water flowing out of the first heat exchanger 21 can flow back to the second heat exchanger 22. An internal circulation waterway can be formed in the gas water heating device, specifically, the internal cavity of the shell 220 of the second heat exchanger 22, the first heat exchanger 21 and the communication pipeline 6 can form an internal circulation waterway.

The gas water heating device may further include a driving device disposed on the internal circulation water path, where the driving device can drive water in the internal circulation water path to sequentially circulate along the inner cavity of the housing 220 of the second heat exchanger 22, the first heat exchanger 21, and the communication pipeline 6.

In particular, the driving means may comprise a water pump 7. Of course, the specific form of the driving device is not limited to the above example, and in the embodiment of the present application, the water pump 7 is mainly exemplified. The internal circulation waterway comprises an inner cavity of the shell 220, the first heat exchanger 21 and the communication pipeline 6; 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 first heat exchanger 21 and the second 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 first heat exchanger 21 and the second heat exchanger 22, 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 second heat exchanger 22 in a form of a housing 220 having a predetermined volume and capable of containing water and a heat exchange pipeline 221 passing through an inner cavity of the housing 220, the flue gas flowing into the heat exchange pipeline 221 can exchange heat with the water in the housing 220, so that the heat exchange efficiency of the second 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, according to the present application, on the basis of the above, the communication pipe 6 that can communicate the outlet 212 of the first heat exchanger 21 with the water inlet 2201 of the second heat exchanger 22 is provided in the gas water heater, and by providing the communication pipe 6, the inner cavity of the housing 220 of the second heat exchanger 22, the first heat exchanger 21 and the communication pipe 6 cooperate to form an internal circulation water path, and when the driving device (for example, the water pump 7) is started, water in the internal circulation water path can be circulated by the water pump 7. By utilizing the internal circulation waterway, when the combustion device 1 is not started, the water temperature in the gas water heating device can be subjected to homogenization treatment, the water temperature difference 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 starting burner 1, can promote the inside temperature of gas water heater to the required preset temperature of user to can be when the user opens gas water heater, can use the hot water that water temperature satisfies the demand, and then reach the purpose that promotes user's use experience 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: the combustion device 1, the first heat exchanger 21 and the second heat exchanger 22, a driving device (e.g., the water pump 7), the communication pipe 6, and the like. In addition, the gas water heating device further comprises a water inlet pipe 4 communicated with the water inlet 2201 of the second heat exchanger 22, a water outlet pipe 5 communicated with the outlet 212 of the first heat exchanger 21, and both the water inlet pipe 4 and the water outlet pipe 5 are communicated with the communication pipeline 6.

Wherein the heat generated by the combustion of the combustion gases of the combustion device 1 is used for heating the fluid flowing through the first heat exchanger 21 and the second heat exchanger 22. In particular, the combustion device 1 may be in the form of a power-adjustable combustion device 1.

The first heat exchanger 21 and the second heat exchanger 22 are used for circulating water to be heated, and the first heat exchanger 21 and the second heat exchanger 22 heat fluid flowing through the inside of the first heat exchanger 21 and the second heat exchanger 22 by heat generated by combustion of fuel gas in the combustion device 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 first heat exchanger 21 and the second heat exchanger 22 are sequentially arranged along the flow direction of the flue gas. Wherein the first heat exchanger 21 is a heat exchanger relatively closer to a smoke generating source (combustion apparatus 1) as a main heat exchanger of the gas water heating apparatus. The first heat exchanger 21 may be in the form of a fin heat exchanger, a plate heat exchanger, a tube heat exchanger, or the like. For example, when the first heat exchanger 21 is a tube heat exchanger, it may include a heat exchange tube that communicates with the inlet 211 and the outlet 212 of the first heat exchanger 21, or ports of the heat exchange tube may serve as the inlet 211 and the outlet 212 of the first heat exchanger 21. Of course, the shape, configuration, etc. of the first heat exchanger 21 may be different according to the actual usage scenario, and the present application is not limited herein.

Specifically, the first heat exchanger 21 may be a stainless steel heat exchanger, and when the first heat exchanger 21 is made of stainless steel, not only can the first heat exchanger 21 be ensured to have better heat exchange performance, but also the first heat exchanger 21 can be ensured to have higher reliability in use, and can be resistant to high temperature and corrosion.

The second heat exchanger 22 may be arranged downstream of the first heat exchanger 21 in the flue gas flow direction. Most of the high-temperature flue gas generated by combustion of the combustion device 1 exchanges heat with the first heat exchanger 21, and then can flow through the second heat exchanger 22 to exchange heat with the second heat exchanger 22 continuously. In an embodiment of the present application, the second heat exchanger 22 may include a hollow housing 220 and a heat exchanging pipe 221 passing through an inner cavity of the housing 220. The heat exchange pipeline 221 is used for circulating smoke, when the smoke flows through the heat exchange pipeline 221, the smoke can exchange heat with water contained in the inner cavity of the shell 220 efficiently, and the smoke cannot occupy the inner space of the gas water heating device too much.

Specifically, the heat exchange tube 221 passing through the inner cavity of the housing 220 of the second heat exchanger 22 may be a stainless steel heat exchange tube 221. When the heat exchange pipeline 221 is made of stainless steel, the heat exchange pipeline 221 can be guaranteed to have better heat exchange performance, and the heat exchange pipeline has higher reliability, high temperature resistance and corrosion resistance in use.

The shell 220 of the second heat exchanger 22 may also be a stainless steel shell, and when the shell 220 is made of stainless steel, the shell 220 can be ensured to have higher reliability, high temperature resistance and corrosion resistance when in use.

In addition, in the embodiment of the present application, the embodiment that the heat exchanging pipe 221 of the second 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 exchanging pipe 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 exchanging pipe 221 may have other matching relationship with the housing 220, and further, the second heat exchanger 22 may have other shapes and configurations.

The housing 220 of the second 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 may be about 1L-2L. Further, the ratio of the volume of the heat exchange pipeline 221 passing through the inner cavity of the shell 220 to the volume of the inner cavity of the shell 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 pipeline 221, realize the secondary full utilization of the energy of the flue gas, ensure the higher heat exchange efficiency of the flue gas and the water, and simultaneously, reasonably control the volume and the ratio of the heat exchange pipeline 221 and the inner cavity of the shell 220, so that the volume of the gas water heating device is not excessively occupied and influenced.

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 pipe having a certain diameter, or may be in the form of a plurality of circular pipes connected in parallel, which does not exclude other shapes and structures of the heat exchanging pipe 221, and the present application is not limited thereto.

The inner cavity of the shell 220 is communicated with the first heat exchanger 21, and the heated water in the inner cavity of the shell 220 and the first 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 first heat exchanger 21.

The gas water heating device may further comprise a communication line 6. In particular, the communication line 6 may be in the form of a hollow pipe, although the communication line 6 may be an internal flow channel formed in the waterway module, or the communication line 6 may be in other forms. In particular, the form of the communication line 6 is not limited in this context.

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 first heat exchanger 21 and the communication pipeline 6. 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.

Wherein the first heat exchanger 21 has an inlet 211 and an outlet 212, and a heat exchange tube communicating with the inlet 211 and the outlet 212. The second heat exchanger 22 has a water inlet 2201 and a water outlet 2202, the water inlet 2201 and the water outlet 2202 being in communication with the interior of the housing 220. The drain 2202 is connected to the inlet 211 to allow water exiting the second heat exchanger 22 to flow into the first heat exchanger 21. The communication pipeline 6 can communicate the outlet 212 of the first heat exchanger 21 with the water inlet 2201 of the second heat exchanger 22, so as to reflux the water flowing out of the outlet 212 of the first heat exchanger 21 to the inner cavity of the shell 220 of the second heat exchanger 22.

Further, for a gas water heating device, it may comprise a water inlet pipe 4 and a water outlet pipe 5 in communication with the heat exchanger. 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 embodiment of the present application, one end of the communication pipe 6 may be connected to the water outlet pipe 5 and the other end of the communication pipe 6 may be connected to the water 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 first heat exchanger 21, a part of water outlet pipe 5, the communication pipeline 6 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, the inner cavity of the housing 220 is connected in series with the first heat exchanger 21 in the water flow direction, and the water in the internal circulation water path circulates through the inner cavity of the housing 220, the first heat exchanger 21 and the communication pipeline 6 sequentially under the action of the water pump 7.

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 first heat exchanger 21, part of the water outlet pipe 5, the communication pipeline 6, part of the water inlet pipe 4 and the inner cavity of the shell 220 in sequence, and returns to the first 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 housing 220 is connected in series with the first heat exchanger 21, and under the action of the water pump 7, the water in the internal circulation waterway can circulate through the first heat exchanger 21, the inner cavity of the housing 220 and the communication pipeline 6 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 first heat exchanger 21, the inner cavity of the housing 220, part of the water inlet pipe 4, the communication pipeline 6, and part of the water outlet pipe 5 in sequence, and returns to the first heat exchanger 21.

Or in other embodiments, the first 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 first 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 disposed on the water outlet pipe 5 downstream of the junction of the communication pipe 6 and the water outlet pipe 5 in the water flow direction, as shown in fig. 3, or the water pump 7 may be disposed on the water inlet pipe 4 downstream of the junction of the communication pipe 6 and the water inlet pipe 4 in the water flow direction, 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 communication pipeline 6 may further be provided with an on-off valve 81, and when the water in the internal circulation waterway circulates, the on-off valve 81 is in a closed state, so that the water in the communication pipeline 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 communication 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 communication pipeline 6, and when the water in the internal circulation waterway circulates, the three-way valve 82 communicates the water outlet pipe 5 with the communication pipeline 6.

In a specific embodiment, a three-way valve 82 is disposed at the connection between the water outlet pipe 5 and the communication pipeline 6, and the three-way valve 82 includes a first interface 821 and a second interface 822 connected to the water outlet pipe 5, and a third interface 823 connected to the communication pipeline 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 communication pipeline 6, and the three-way valve 82 communicates the communication pipeline 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 part of the water inlet pipe 4 and the communication pipeline 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 communication pipeline 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 waterway is in the form of a three-way valve 82, the three-way valve 82 may be a flow-adjustable three-way valve.

When the valve element is a flow-adjustable three-way valve, hot water flowing out of the heat exchanger and cold water flowing in of the communication pipeline 6 can be mixed in a proper proportion by utilizing the flow-adjustable three-way valve, so that water meeting the preset temperature requirement can be 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 needed mixed cold water amount has uncertainty, and particularly, the phenomenon that the water outlet temperature is unstable is easy to cause when the user uses water at multiple points can be prevented.

Referring to fig. 5, in some embodiments, an electrically operated water valve 84 is provided on the communication line 6 for regulating the flow of water in the communication line 6.

In the present embodiment, the electric water valve 84 is provided in the communication pipe 6, so that the water flow rate in the communication 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 can be electrically connected with a controller, and the opening degree of the electric water valve 84 is adjusted according to a control signal of the controller, so that the flow rate of water in the communication pipeline 6 is adjusted. 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 communication pipe 6 circulates.

When the water of the internal circulation waterway circulates, since the communication pipe 6 forms a part of the internal circulation waterway, water having a predetermined flow rate flows through the communication pipe 6. Wherein the flow rate of the water flowing through the communication 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 communication pipe 6 does not circulate, or so that water entering the gas water heater from the inlet pipe 4 partially flows into the communication pipe 6 and partially flows into the inner cavity of the housing 220 of the second 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 communication pipe 6 does not flow; or the second opening degree may be a smaller opening degree value, so that a larger pipe resistance is generated in the communication pipeline 6, so that water entering the gas water heating device from the water inlet pipe 4 flows into the communication pipeline 6 partially and flows into the inner cavity of the shell 220 of the second heat exchanger 22 partially.

As shown in fig. 6, a second temperature sensor 92 may be disposed on the water outlet pipe 5 of the gas water heating device and located upstream of the connection position of the communication pipe 6 and the water outlet pipe 5, and a fourth temperature sensor 94 may be disposed on the water outlet pipe 5 and located downstream of the connection position of the communication pipe 6 and the water 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 communication pipe 6 may be provided with a check valve 83, and the check valve 83 is configured to enable water to flow unidirectionally only from one end of the communication pipe 6 connected to the water outlet pipe 5 to the other end of the communication 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 communication pipe 6 during the internal circulation process.

In this embodiment of the present application, the gas water heater may further include a fan 3, and after the fan 3 is started, the flue gas generated by the combustion of the combustion device 1 can be driven to flow to the first heat exchanger 21 and the second heat exchanger 22 in sequence.

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. The fan 3 may specifically be a variable frequency fan, for example. 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 fan 3 is disposed between the first heat exchanger 21 and the second heat exchanger 22, the air inlet of the fan 3 is located downstream of the first heat exchanger 21 along the flow direction of the flue gas, and the air outlet of the fan 3 is located upstream of the second heat exchanger 22 along the flow direction of the flue gas and is in communication with the inner cavity of the heat exchange tube 221 of the second heat exchanger 22.

The first heat exchanger 21, the fan 3 and the second heat exchanger 22 are sequentially arranged along the flow direction of the flue gas, and at least part of the flue gas exhausted by the fan 3 can exchange heat with water in the inner cavity of the shell 220 after entering the heat exchange pipeline 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 first heat exchanger 21, and the air outlet may be in communication with the heat exchanging pipe 221 of the second heat exchanger 22. On the flowing direction of the flue gas, the first heat exchanger 21, the fan 3 and the second heat exchanger 22 are sequentially arranged, the flue gas generated by the combustion of the combustion device 1 can exchange heat with the first heat exchanger 21, the flue gas after exchanging heat with the first heat exchanger 21 enters the fan 3, then enters the heat exchange pipeline 221 of the second heat exchanger 22 to exchange heat with water in the shell 220, and finally is discharged outwards through the smoke exhaust pipe 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 first heat exchanger 21, and the second heat exchanger 22 is disposed obliquely above the first heat exchanger 21.

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

In addition, the gas water heating device can be a lower blowing type gas water heating device. When the gas water heating device is in the form of a lower blast, the fan 3, the combustion device 1, and the first heat exchanger 21 are disposed in this order in the height direction. The second heat exchanger 22 may be arranged downstream of the first heat exchanger 21 in the flue gas flow direction.

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 first heat exchanger 21, and a third temperature sensor 93 for detecting a water temperature between the inner cavity of the housing 220 and the first 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 housing 220, a second temperature sensor 92 for detecting the water temperature exiting the first heat exchanger 21, and a third temperature sensor 93 for detecting the water temperature between the inner cavity of the housing 220 and the first 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 communication line 6, the second temperature sensor 92 may be disposed on the connection pipe 23 between the inner cavity of the housing 220 and the first 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 communication line 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 the embodiment of the application, the gas water heating device can be further provided with a smoke exhaust pipe 24, wherein the smoke exhaust pipe 24 is positioned at the most downstream along the smoke flow direction, and can be used for exhausting the smoke after heat exchange of the heat exchanger out of the gas water heating device. The smoke exhaust pipe 24 may be mounted on the top of the gas water heater housing. One end of the smoke exhaust pipe 24 can be communicated with the heat exchanger, and the other end of the smoke exhaust pipe 24 extends out of the shell and is connected to the outside. A wind cap 25 may be provided at an end of the smoke discharge pipe 24 located outdoors. The wind-proof cap 25 can be electrically connected with a controller, when the combustion device 1 is in a non-starting state, the wind-proof cap 25 is in a closed state, so that the problems of indoor air pollution, particularly when the ambient temperature is low, the brought extremely low temperature frost cracks the shell 220 containing water and the like caused by the fact that strong wind outside flows back into the gas water heating device are prevented; when the combustion device 1 is in the starting state, the wind cap 25 is in the opening state, so that the smoke exhaust pipe 24 can reliably exhaust the smoke outwards.

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 combustion device 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 second heat exchanger 22, the second heat exchanger 22 is provided with the shell 220 with a preset volume, the heat exchange pipeline 221 passes 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 combustion device 1 is not started, and further the combustion device 1 is prevented from being started by frequent ignition of the gas water heating device, 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 pipeline 221 passes through the shell 220 and can exchange heat with water in the shell 220, the heat exchange efficiency of the second 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 outlet water temperature has fallen by a predetermined temperature on the basis of the preset temperature, or the difference in the outlet water temperature reaches a predetermined temperature difference, the combustion apparatus 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 combustion device 1 in the gas water heater can normally start combustion.

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 combustion device 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 (21)

1. The gas water heating device is characterized by comprising a combustion device and a first heat exchanger and a second heat exchanger which are sequentially arranged along the flow direction of flue gas generated by the combustion device;

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

The first heat exchanger is communicated with the second heat exchanger, and water flowing out of the inner cavity of the shell of the second heat exchanger flows into the first heat exchanger;

The gas water heating device is internally provided with a communication pipeline which can be used for communicating the outlet of the first heat exchanger with the water inlet of the second heat exchanger, and the communication pipeline can be used for refluxing water flowing out of the first heat exchanger to the second heat exchanger; the shell inner cavity of the second heat exchanger, the first heat exchanger and the communication pipeline can form an internal circulation waterway.

2. The gas water heating device according to claim 1, further comprising a driving device arranged on the internal circulation water path, wherein the driving device can drive water in the internal circulation water path to sequentially circulate along the inner cavity of the shell of the second heat exchanger, the first heat exchanger and the communication pipeline.

3. The gas water heating apparatus of claim 2, wherein the second heat exchanger further comprises a drain, the water inlet and drain being in communication with the housing interior cavity;

The first heat exchanger further comprises an inlet and a heat exchange tube, the heat exchange tube is communicated with the inlet and the outlet, and the water outlet is connected with the inlet so that water flowing out of the second heat exchanger flows into the first heat exchanger.

4. A gas water heating apparatus as claimed in claim 3, wherein the communication line communicates the outlet with the water inlet to return water flowing out of the first heat exchanger outlet to the second heat exchanger housing interior.

5. A gas water heating apparatus as claimed in claim 2, wherein the drive means comprises a water pump.

6. The gas water heating device according to claim 5, further comprising a water inlet pipe in communication with the water inlet of the second heat exchanger, a water outlet pipe in communication with the outlet of the first heat exchanger, both the water inlet pipe and the water outlet pipe in communication with the communication pipe;

The water pump is arranged on the water outlet pipe and is positioned at the upstream of the joint of the communication pipeline and the water outlet pipe in the water flow direction,

Or alternatively

The water pump is arranged on the water inlet pipe and is positioned at the downstream of the joint of the communication pipeline and the water inlet pipe in the water flow direction.

7. A gas water heating apparatus according to claim 6, wherein,

The communicating pipeline is also provided with a switch valve, and when the water in the internal circulation waterway circulates, the switch valve is in an open state so that the water in the communicating pipeline circulates;

Or a three-way valve is arranged at the joint of the water outlet pipe and the communication pipeline, and the three-way valve communicates the water outlet pipe with the communication pipeline when water in the internal circulation waterway circulates;

or the junction of inlet tube with the intercommunication pipeline is provided with the three-way valve, when the water of inner loop water route circulates, the three-way valve will the intercommunication pipeline with the inlet tube intercommunication.

8. A gas water heating apparatus according to claim 6, wherein the communication 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 communication pipe does not circulate.

9. A gas water heating apparatus according to claim 6, wherein the communication pipe is provided with an electric water valve for adjusting the flow rate of water in the communication pipe.

10. A gas water heating apparatus according to claim 9, wherein the electric water valve has a first opening degree when water in the internal circulation water path circulates, so that water in the communication pipe is circulated.

11. A gas water heating apparatus according to claim 10, 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 communication pipe is not circulated, or so that water entering the gas water heating apparatus from the inlet pipe partially flows into the communication pipe and partially flows into the second heat exchanger housing inner chamber.

12. A gas water heating apparatus according to claim 9, 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 such that water in the communication line is not circulated, or such that water entering the gas water heating apparatus from the inlet pipe partially flows into the communication line and partially flows into the second heat exchanger housing interior.

13. The gas water heating device according to claim 6, wherein a three-way valve is arranged at the connection part of the water outlet pipe and the communication pipeline, 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 communication pipeline; 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.

14. The gas water heating device according to claim 6, wherein a three-way valve is arranged at the connection of the water inlet pipe and the communication pipeline, 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 communication pipeline; 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.

15. A gas water heating apparatus according to claim 6, wherein the communication pipe is provided with a check valve for allowing water to flow only in one direction from one end of the communication pipe connected to the water outlet pipe to the other end of the communication pipe connected to the water inlet pipe.

16. The gas water heater as recited in claim 1, further comprising a fan, wherein after the fan is started, the flue gas generated by the combustion of the combustion device can be driven to flow to the first heat exchanger and the second heat exchanger in sequence.

17. A gas water heating apparatus according to claim 16, wherein the fan is disposed between the first heat exchanger and the second heat exchanger, an air inlet of the fan is located downstream of the first heat exchanger in a flue gas flow direction, and an air outlet of the fan is located upstream of the second heat exchanger in the flue gas flow direction and is in communication with a heat exchange tube inner chamber of the second heat exchanger.

18. A gas water heating apparatus according to claim 1, wherein the volume of the housing cavity ranges from: 1 liter to 2 liters.

19. A gas water heating apparatus according to claim 1, wherein the ratio of the volume of the heat exchange conduit to the volume of the housing interior is in the range 1/3 to 1/2.

20. A gas water heating apparatus according to claim 1, wherein the heat exchange conduit passing through the housing cavity of the second heat exchanger is a stainless steel heat exchange conduit.

21. A gas water heating apparatus as claimed in claim 20, wherein the housing is a stainless steel housing and the first heat exchanger is a stainless steel heat exchanger.