CN111692744A

CN111692744A - Gas water heater

Info

Publication number: CN111692744A
Application number: CN201910205934.1A
Authority: CN
Inventors: 李茂照; 黄官贤; 刘继锋; 寿利萍; 梁国荣
Original assignee: Wuhu Midea Kitchen and Bath Appliances Manufacturing Co Ltd
Current assignee: Wuhu Midea Kitchen and Bath Appliances Manufacturing Co Ltd
Priority date: 2019-03-15
Filing date: 2019-03-15
Publication date: 2020-09-22

Abstract

The invention discloses a gas water heater, which comprises: the heat exchanger is provided with a water flow pipeline, the water flow pipeline is provided with a water inlet and a water outlet, and the water inlet is communicated with a water supply source; the fan assembly is arranged above the heat exchanger and is provided with an air inlet for air to enter and an air inlet for fuel gas to enter. The technical scheme of the invention is beneficial to improving the working stability and safety of the gas water heater.

Description

Gas water heater

Technical Field

The invention relates to the technical field of gas water heaters, in particular to a gas water heater.

Background

In the existing gas water heater, a fan structure is positioned below the whole water heater, and airflow enters from the lower part and is discharged from the upper part of the water heater. And water will produce the comdenstion water at the in-process with the heat transfer of heat transfer structure, and the comdenstion water flows downwards under the effect of gravity for the fan structure that is located heat transfer structure below has the hidden danger that is instiled into by the comdenstion water, so, is unfavorable for the stable work of gas heater.

Disclosure of Invention

The invention mainly aims to provide a gas water heater, aiming at reducing the influence of condensed water on the working stability of the water heater and improving the working safety and stability of the gas water heater.

In order to achieve the above object, the present invention provides a gas water heater, comprising:

the heat exchanger is provided with a water flow pipeline, the water flow pipeline is provided with a water inlet and a water outlet, and the water inlet is communicated with a water supply source;

the fan assembly is arranged above the heat exchanger and is provided with an air inlet for air to enter and an air inlet for fuel gas to enter.

Preferably, the gas water heater is provided with a gas mixing cavity, an inlet of the gas mixing cavity is communicated with an air outlet of the fan assembly, an outlet of the gas mixing cavity is communicated with a burner of the gas water heater, and the burner is arranged corresponding to the heat exchanger.

Preferably, the burner comprises a preheating burner and a catalytic burner, the preheating burner being located below the catalytic burner.

Preferably, the heat exchanger comprises a first heat exchanger and a second heat exchanger, the water flow pipeline comprises a first heat exchange pipeline arranged on the first heat exchanger, and a second heat exchange pipeline arranged on the second heat exchanger;

the first heat exchange pipeline and the second heat exchange pipeline are connected in series.

Preferably, the gas water heater further comprises a water inlet pipeline and a water outlet pipeline; the water inlet pipeline is communicated with a water inlet of the second heat exchange pipeline and a water source, and the water outlet pipeline is communicated with a water outlet of the first heat exchange pipeline and the outside; the water outlet of the second heat exchange pipeline is communicated with the water inlet of the first heat exchange pipeline;

the gas water heater also comprises a first bypass pipeline, and the first bypass pipeline is communicated with the water inlet pipeline and the water outlet pipeline; alternatively, the first and second electrodes may be,

the first bypass pipeline is communicated with the water outlet pipeline and the first heat exchange pipeline; alternatively, the first and second electrodes may be,

the first bypass pipeline is communicated with the water outlet pipeline and the second heat exchange pipeline.

the first heat exchange pipeline and the second heat exchange pipeline are connected in parallel.

Preferably, the gas water heater further comprises a water inlet pipeline and a water outlet pipeline; the water inlet pipeline is communicated with water inlets of the first heat exchange pipeline and the second heat exchange pipeline and a water source; the water outlet pipeline is communicated with the water outlets of the first heat exchange pipeline and the second heat exchange pipeline and the outside;

the gas water heater also comprises a second bypass pipeline, and the second bypass pipeline is communicated with the water inlet pipeline and the water outlet pipeline; alternatively, the first and second electrodes may be,

the second bypass pipeline is communicated with the water outlet pipeline and the first heat exchange pipeline; and/or the presence of a gas in the gas,

the second bypass pipeline is communicated with the water outlet pipeline and the second heat exchange pipeline.

Preferably, a bypass control valve is provided on the second bypass pipe.

Preferably, a water outlet pipeline of the gas water heater is provided with a liquid storage tank.

Preferably, a flow control valve is arranged on the first heat exchange pipeline and/or the second heat exchange pipeline.

Preferably, the gas water heater further comprises a preheating heat exchanger;

the preheating heat exchanger is provided with a preheating pipeline, a water inlet of the preheating pipeline is communicated with a water source, and a water outlet of the preheating pipeline is communicated with a water inlet of the first heat exchange pipeline and/or the second heat exchange pipeline.

Preferably, the first heat exchanger and the second heat exchanger are arranged from top to bottom along the height direction of the gas water heater;

the preheating heat exchanger is arranged below the second heat exchanger.

Preferably, the gas heat exchanger further comprises a fume collecting hood assembly, and the fume collecting hood assembly is communicated with the exhaust port of the preheating heat exchanger.

Preferably, the gas water heater further comprises a condensed water collecting pipeline, and the condensed water collecting pipeline is arranged corresponding to the water flow pipeline to collect and discharge condensed water.

According to the technical scheme, in the working process of the gas water heater, low-temperature water in the water flow pipeline exchanges heat with the heat exchanger, condensed water formed in the process flows downwards under the action of gravity, and the fan assembly is located above the heat exchanger and the water flow pipeline, so that the condensed water cannot fall into the fan assembly, the influence of the condensed water on the fan assembly is avoided, and the working stability and safety of the fan assembly are improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic structural view of an embodiment of a gas water heater according to the present invention;

FIG. 2 is a schematic structural view of another embodiment of the gas water heater of the present invention;

FIG. 3 is a schematic structural view of yet another embodiment of the gas water heater of the present invention;

FIG. 4 is a schematic structural view of a gas water heater according to yet another embodiment of the present invention;

fig. 5 is a schematic structural diagram of a gas water heater according to still another embodiment of the present invention.

The reference numbers illustrate:

the implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The invention mainly provides a gas water heater, which is characterized in that a fan assembly 100 is arranged above a heat exchanger (heat exchange pipeline), so that condensed water formed by heat exchange does not fall into the fan assembly 100 any more, the fan assembly 100 is not influenced by the condensed water, the working stability of the fan assembly 100 is favorably improved, and the working stability and the safety of the gas water heater are favorably improved; through setting up two mutually independent first heat exchanger 510 and second heat exchanger 520 to the first heat transfer pipeline 511 that will correspond with first heat exchanger 510 and the parallel arrangement of second heat transfer pipeline 521 that corresponds with second heat exchanger 520, make first heat transfer pipeline 511 and second heat transfer pipeline 521 can mutual independent control, so, make the heat transfer condition of first heat exchanger 510 can adjust through first heat transfer pipeline 511, the heat transfer condition of second heat exchanger 520 can adjust through second heat transfer pipeline 521, thereby be favorable to making first heat exchanger 510 and second heat exchanger 520 heat transfer abundant, reasonable utilization heat energy, simultaneously, also, can reduce or even eliminate the formation of heat exchange pipeline comdenstion water. Therefore, the heat energy utilization rate is improved, and the formation of condensed water is favorably reduced.

In order to facilitate understanding of the technical solutions, the complete technical solutions are summarized. The gas water heater mainly comprises a fan assembly 100 positioned at the top of the water heater, a gas mixing cavity 200 communicated with the fan assembly 100 and positioned below the fan assembly, and a first heat exchanger 510 and a second heat exchanger 520 positioned below the gas mixing cavity 200. A preheating burner 300 is disposed between the gas mixing chamber 200 and the first heat exchanger 510, and a catalytic burner 300 is disposed between the first heat exchanger 510 and the second heat exchanger 520. A preheating heat exchanger 530 is also provided below the second heat exchanger 520. The fume collecting hood assembly 600 is disposed below the preheat heat exchanger 530 and communicates with an air outlet of the preheat heat exchanger 530. So set up for after air and gas mix under the fan effect, further evenly mix in mixing gas cavity 200, again from last to passing through preheating combustor 300, first heat exchanger 510, catalytic combustor 300, second heat exchanger 520, preheating heat exchanger 530 in proper order down. The first heat exchanger 510 is provided with a first heat exchange pipeline 511, the second heat exchanger 520 is provided with a second heat exchange pipeline 521, and the preheating heat exchanger 530 is provided with a preheating pipeline. Under the condition that the first heat exchange pipeline 511 and the second heat exchange pipeline 521 are connected in series, water flows sequentially through the preheating pipeline, the second heat exchange pipeline 521 and the first heat exchange pipeline 511 from bottom to top, and then is discharged from the water outlet pipeline 900; under the condition that the first heat exchange pipeline 511 and the second heat exchange pipeline 521 are connected in parallel, water flows from bottom to top sequentially through the preheating pipeline and the second heat exchange pipeline 521, or sequentially through the preheating pipeline and the first heat exchange pipeline 511, and then is discharged from the water outlet pipeline 900.

The specific structure of the gas water heater will be described below mainly in terms of embodiments.

Referring to fig. 1 to 5, in an embodiment of the present invention, the gas water heater includes:

the heat exchanger 500 is provided with a water flow pipeline, the water flow pipeline is provided with a water inlet and a water outlet, and the water inlet is communicated with a water supply source;

the fan assembly 100 is arranged above the heat exchanger 500, and the fan assembly 100 is provided with an air inlet 110 for air to enter and an air inlet for fuel gas to enter.

Specifically, in the embodiment, the heat exchanger 500 is a component for realizing heat conversion, and the heat exchanger 500 is provided with a water flow pipeline, which may be formed on the heat exchanger 500 itself or may be an additional pipeline structure, such as a water pipe. The water flow pipeline has a water inlet and a water outlet, and water flows in from the water inlet and out from the water outlet, and exchanges heat with the heat exchanger 500 in the process of passing through the water flow pipeline.

The fan assembly 100 is provided with a connector communicated with the gas pipeline 400 and an air inlet 110, and is connected and communicated with the gas inlet pipe. During operation of fan assembly 100, air enters fan assembly 100 from air inlet 110, and fuel gas enters fan assembly 100 through the air inlet pipe and the air inlet. The air and gas may be initially mixed in the fan assembly 100. Of course, in some embodiments, the air inlet 110 also has a structure for preventing the gas from diffusing outwards, so as to ensure the safety of use. The fan assembly 100 is electrically connected with a controller of the gas water heater in a wireless connection mode, and also can be connected with the controller through an electric connection line, and the controller can adjust the rotating speed of the fan according to actual requirements.

It is noted that the gas pipeline 400 may be provided with a gas ratio to control and regulate the gas flow.

In this embodiment, in the course of working of gas heater, the low temperature water in the rivers pipeline carries out the heat transfer with heat exchanger 500, and the comdenstion water that forms at this in-process will flow downwards under the action of gravity, because fan subassembly 100 is located the top of heat exchanger 500 and rivers pipeline for the comdenstion water can not fall into in fan subassembly 100, thereby has avoided the influence of comdenstion water to fan subassembly 100, has improved fan subassembly 100 job stabilization nature and security.

In some embodiments, in order to improve the mixing degree of the air and the gas, the gas water heater has a gas mixing cavity 200, an inlet of the gas mixing cavity 200 is communicated with an air outlet of the fan assembly 100, an outlet of the gas mixing cavity 200 is communicated with a burner 300 of the gas water heater, and the burner 300 is arranged corresponding to the heat exchanger 500. The fully mixed gas enters the burner 300 to be burned, and the temperature of the heat exchanger 500 is increased, thereby providing heat energy for the water flow pipeline. The number of the burner 300 may be plural, and in this embodiment, in order to improve the combustion efficiency of the fuel gas and reduce the generation of the exhaust gas, the burner 300 is configured to include a preheating burner 310 and a catalytic burner 320, and the catalytic burner 320 is located below the catalytic burner 320. In order to uniformly introduce the gas from the gas mixing chamber 200 into each burner 300, a gas distribution device (not shown) may be disposed in the gas mixing chamber 200, and the gas distribution device may uniformly distribute the mixed gas of the combustible gas and the air to each burner 300.

The preheating burner 310 is made of porous ceramic material, air and gas are mixed according to a certain proportion and then are combusted at the position, the cavity is preheated, and after the temperature is raised to a certain temperature, the open flame combusted on the burner 300 is gradually extinguished. A catalytic burner 320, a component that realizes flameless catalytic combustion; comprises a substrate, a carrier, a catalyst and the like. The substrate is preferably made of porous ceramic, the substrate can resist high temperature of 1200 ℃, the surface of the substrate is coated with catalysts (which can be divided into two types, namely noble metal and nonmetal catalysts), the catalysts can reduce the ignition temperature of the fuel and deepen the oxidation degree of the fuel, and open flames are extinguished after the substrate is preheated to a certain temperature, so that organic matters are converted into self-sustaining flameless combustion at a lower ignition temperature.

The catalyst arranged on the catalytic combustor 320 can enable organic matters to be flameless combusted at a lower ignition temperature, reduce harmful gas generated during ignition of fuel and release a large amount of heat, reactant molecules of the fuel can be enriched on the surface of the catalyst, the reaction rate is improved, the utilization rate of the fuel is improved, the catalyst can effectively inhibit the generation of nitrogen oxides, and meanwhile, the catalyst can enable the catalytic combustion of the fuel to be complete, reduce the content of carbon monoxide in smoke, and further effectively reduce the emission of the harmful gas. Because of flameless combustion, the combustion reaction is soft and stable, and the combustion noise generated when the water heater with open flame works is reduced, thereby the noise generated when the water heater works is smaller.

The number of the heat exchangers 500 may be one or multiple, the heat exchange pipelines corresponding to different heat exchangers may be connected in series or in parallel, and the following description will specifically refer to two heat exchangers as an example.

The heat exchange pipelines corresponding to the two heat exchangers are connected in series:

the heat exchanger 500 comprises a first heat exchanger 510 and a second heat exchanger 520, the water flow pipeline comprises a first heat exchange pipeline 511 arranged on the first heat exchanger 510, and a second heat exchange pipeline 521 arranged on the second heat exchanger 520; the first heat exchange line 511 and the second heat exchange line 521 are connected in series.

In this embodiment, the first heat exchange pipeline 511 corresponding to the first heat exchanger 510 and the second heat exchange pipeline 521 corresponding to the second heat exchanger 520 are connected in series, so that the water flow sequentially passes through the first heat exchange pipeline 511 and the second heat exchange pipeline 521, or sequentially passes through the second heat exchange pipeline 521 and the first heat exchange pipeline 511. The water flow is subjected to two heat exchanges in the flowing process, and the water temperature after heat exchange is fully ensured.

In some embodiments, to increase the safety of a user using the gas water heater, the gas water heater further comprises a water inlet line 800 and a water outlet line 900; the water inlet pipeline 800 is communicated with a water inlet of the second heat exchange pipeline 521 and a water source, and the water outlet pipeline 900 is communicated with a water outlet of the first heat exchange pipeline 511 and the outside; the water outlet of the second heat exchange pipeline 521 is communicated with the water inlet of the first heat exchange pipeline 511;

the gas water heater also comprises a first bypass pipe 850, and the first bypass pipe 850 is communicated with the water inlet pipe 800 and the water outlet pipe 900; alternatively, the first and second electrodes may be,

the first bypass pipe 850 is communicated with the water outlet pipe 900 and the first heat exchange pipe 511; alternatively, the first and second electrodes may be,

the first bypass pipe 850 communicates the water outlet pipe 900 and the second heat exchange pipe 521.

In this embodiment, in order to better input and output water flow to and from the gas water heater, a water inlet pipeline 800 and a water outlet pipeline 900 are respectively provided. The bypass pipe is preferably communicated with the water inlet end and the water outlet end, namely the water inlet pipeline 800 and the water outlet pipeline 900; it is also possible to connect the water outlet line 900 with the coils of the heat exchanger 500, i.e. to connect the water outlet line 900 with the first heat exchange line 511 or the second heat exchange line 521. When the user turns off the water halfway in the process of using the gas water heater, the residual heat in the heat exchanger 500 can continue to heat the hot water in the pipe, and the water temperature can be higher than the temperature set by the user. When the user opens the water outlet again, in order to avoid the hot water with high temperature from scalding the user, the water heater with the first bypass pipe 850 can neutralize the hot water with high temperature by the flowing water of the first bypass pipe 850, so that the hot water flowing out finally is still the water temperature set by the user. Therefore, the water temperature requirement of a user is met, and the potential safety hazard that the user is scalded by high-temperature hot water is eliminated.

The heat exchange pipelines corresponding to the two heat exchangers are connected in parallel:

the heat exchanger 500 comprises a first heat exchanger 510 and a second heat exchanger 520, the water flow pipeline comprises a first heat exchange pipeline 511 arranged on the first heat exchanger 510, and a second heat exchange pipeline 521 arranged on the second heat exchanger 520;

the first heat exchange line 511 and the second heat exchange line 521 are connected in parallel.

In this embodiment, the first heat exchange pipeline 511 and the second heat exchange pipeline 521 are connected in parallel, the first heat exchange pipeline 511 and the second heat exchange pipeline 521 are respectively and independently communicated with a water source, and the hot water output is also independent and does not affect each other. In this way, the heat exchange of the first heat exchange pipeline 511 and the second heat exchange pipeline 521 are independent from each other, so that the water flow in the first heat exchange pipeline 511 and the second heat exchange pipeline 521 can be adjusted according to the heat exchange conditions with the first heat exchanger 510 and the second heat exchanger 520. So as to fully ensure the sufficient heat exchange between the first heat exchange pipeline 511 and the first heat exchanger 510, and the sufficient heat exchange between the second heat exchange pipeline 521 and the second heat exchanger 520, thus fully utilizing the heat energy and simultaneously reducing the formation of condensed water as much as possible.

In some embodiments, a water inlet line 800 and a water outlet line 900 are provided for better input and output of water flow to the gas water heater. The gas water heater also comprises a water inlet pipeline 800 and a water outlet pipeline 900; the water inlet pipeline 800 is communicated with water sources and water inlets of the first heat exchange pipeline 511 and the second heat exchange pipeline 521; the water outlet pipeline 900 is communicated with the water outlets of the first heat exchange pipeline 511 and the second heat exchange pipeline 521 and the outside;

the gas water heater also comprises a second bypass pipe 860, and the second bypass pipe 860 is communicated with the water inlet pipeline 800 and the water outlet pipeline 900; alternatively, the first and second electrodes may be,

the second bypass pipe 860 is communicated with the water outlet pipeline 900 and the first heat exchange pipeline 511; and/or the presence of a gas in the gas,

the second bypass pipe 860 communicates the water outlet pipe 900 and the second heat exchange pipe 521.

In this embodiment, the water inlets of the first heat exchange pipeline 511, the second heat exchange pipeline 521 and the second bypass pipeline 860 are respectively communicated with the water outlet end of the water inlet pipeline 800, and the water outlet ends of the first heat exchange pipeline 511, the second heat exchange pipeline 521 and the second bypass pipeline 860 are respectively communicated with the water outlet pipeline 900. In order to adjust and control the water flow rate in the first heat exchange pipeline 511, the second heat exchange pipeline 521 and the second bypass pipeline 860, a control valve for detecting a water flow signal and adjusting the water flow rate is provided in each branch. That is, in order to adjust the flow rate in the water flow line, so as to adjust the heat exchange condition between the water flow line and the heat exchanger 500, a flow control valve is disposed on the first heat exchange line 511 and/or the second heat exchange line 521.

Of course, the flow control valve and the detection device for detecting the water flow signal are both electrically connected to the controller, the detected water flow signal is transmitted to the controller, and the controller adjusts the control valve according to the temperature condition and the water flow condition in the heat exchanger, so as to adjust the flow rates in the first heat exchange pipeline 511, the second heat exchange pipeline 521 and the second bypass pipeline 860 respectively.

Of course, in some embodiments, only a control valve for controlling on/off may be disposed on the second bypass pipe 860, when the gas water heater works normally, the second bypass pipe 860 is closed by the control valve, and when the water heater starts to work, the second bypass pipe 860 is conducted by the control valve, so that the low-temperature water can neutralize the high-temperature water, and the high-temperature water is prevented from scalding the user.

In some embodiments, in order to improve the uniformity of the outlet water temperature of the gas water heater, a liquid storage tank is disposed on the outlet pipe 900 of the gas water heater. When the water after heat exchange flows out from the water outlet pipeline 900, the water enters the liquid storage tank to be mixed, so that the situation that the water temperature after heat exchange is uneven due to reasons such as water pressure fluctuation and the like is avoided, the water temperature flowing out from the liquid storage tank is constant, and the use of a water heater by a user is facilitated.

In some embodiments, to further improve the utilization of the heat energy, the gas water heater further comprises a preheat exchanger 530; the preheating heat exchanger 530 is provided with a preheating pipeline, a water inlet of the preheating pipeline is communicated with a water source, and a water outlet of the preheating pipeline is communicated with a water inlet of the first heat exchange pipeline 511 and/or the second heat exchange pipeline 521. In this embodiment, the combustion gas enters the preheating heat exchanger 530 after passing through the first heat exchanger 510 and the second heat exchanger 520, and the water flow passes through the preheating pipeline, the first heat exchange pipeline 511 or the second heat exchange pipeline 521. Although the temperature of the preheat exchanger 530 is lower, it is still higher than the temperature of the normal temperature water, so the water flow passing through the preheat heat exchange pipeline can be preheated to fully utilize the heat energy generated by combustion.

It should be noted that, in order to sufficiently improve the utilization rate of energy, the first heat exchanger 510 and the second heat exchanger 520 are arranged from top to bottom along the height direction of the gas water heater; the preheat heat exchanger 530 is disposed below the second heat exchanger 520. The gas heat exchanger further comprises a fume collecting hood assembly 600, and the fume collecting hood assembly 600 is communicated with an exhaust port of the preheating heat exchanger 530. The combusted gas firstly passes through the first heat exchanger 510, the second heat exchange and preheating heat exchanger 530 from top to bottom, and then is discharged upwards through the smoke discharge pipe 610 under the action of the smoke collection cover assembly 600.

In some embodiments, in order to improve the ability of the gas water heater to centrally treat the condensed water, the gas water heater further includes a condensed water collecting pipe 700, and the condensed water collecting pipe 700 is disposed corresponding to the water flow pipe to collect and discharge the condensed water. The condensed water is discharged from the condensed water collecting pipe 700, and of course, before being discharged, the condensed water may be treated by the water treatment device 710 to avoid directly discharging the condensed water with acidic corrosion.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A gas water heater, comprising:

2. The gas water heater of claim 1, wherein the gas water heater has a gas mixing cavity, an inlet of the gas mixing cavity is communicated with an air outlet of the fan assembly, an outlet of the gas mixing cavity is communicated with a burner of the gas water heater, and the burner is arranged corresponding to the heat exchanger.

3. The gas water heater of claim 2, wherein said burner includes a preheating burner and a catalytic burner, said preheating burner being located below said catalytic burner.

4. The gas water heater of claim 1, wherein the heat exchanger comprises a first heat exchanger and a second heat exchanger, and the water flow line comprises a first heat exchange line disposed on the first heat exchanger, a second heat exchange line disposed on the second heat exchanger;

5. The gas water heater of claim 4, further comprising a water inlet line and a water outlet line; the water inlet pipeline is communicated with a water inlet of the second heat exchange pipeline and a water source, and the water outlet pipeline is communicated with a water outlet of the first heat exchange pipeline and the outside; the water outlet of the second heat exchange pipeline is communicated with the water inlet of the first heat exchange pipeline;

6. The gas water heater of claim 1, wherein the heat exchanger comprises a first heat exchanger and a second heat exchanger, and the water flow line comprises a first heat exchange line disposed on the first heat exchanger, a second heat exchange line disposed on the second heat exchanger;

7. The gas water heater of claim 6, further comprising a water inlet line and a water outlet line; the water inlet pipeline is communicated with water inlets of the first heat exchange pipeline and the second heat exchange pipeline and a water source; the water outlet pipeline is communicated with the water outlets of the first heat exchange pipeline and the second heat exchange pipeline and the outside;

8. The gas fired water heater of claim 7, wherein a bypass control valve is provided on said second bypass line.

9. The gas water heater of claim 1, wherein the outlet line of the gas water heater is provided with a reservoir.

10. The gas water heater as claimed in any one of claims 4 to 9, wherein a flow control valve is provided on the first heat exchange line and/or the second heat exchange line.

11. The gas water heater of any one of claims 4 to 9, further comprising a preheat heat exchanger;

12. The gas water heater of claim 11, wherein the first heat exchanger and the second heat exchanger are arranged from top to bottom along a height direction of the gas water heater;

the preheating heat exchanger is arranged below the second heat exchanger.

13. The gas water heater of claim 12, wherein the gas heat exchanger further includes a smoke collection hood assembly in communication with an exhaust port of the preheat heat exchanger.

14. The gas water heater as claimed in any one of claims 1 to 8, further comprising a condensed water collecting line disposed in correspondence with the water flow line to collect and discharge condensed water.