CN212006251U

CN212006251U - Water heating device

Info

Publication number: CN212006251U
Application number: CN202020127169.4U
Authority: CN
Inventors: 张永明; 黄官贤; 李茂照; 梁国荣; 倪双跃
Original assignee: Midea Group Co Ltd; Wuhu Midea Kitchen and Bath Appliances Manufacturing Co Ltd
Current assignee: Midea Group Co Ltd; Wuhu Midea Kitchen and Bath Appliances Manufacturing Co Ltd
Priority date: 2020-01-19
Filing date: 2020-01-19
Publication date: 2020-11-24
Anticipated expiration: 2030-01-19

Abstract

The utility model discloses a water heating equipment, water heating equipment includes: a housing having an air inlet and an air outlet forming an air flow passage therebetween; a catalytic burner disposed at least partially within the gas flow passage and configured to perform catalytic combustion; a preheating burner disposed at least partially within the gas flow passage and for preheating the catalytic burner; the first heat exchanger is at least partially arranged in the airflow channel and is respectively communicated with a first water inlet pipe and a first water outlet pipe; and the second heat exchanger is arranged on the shell and is in thermal communication with the first water outlet pipe, and the second heat exchanger is respectively communicated with a second water inlet pipe and a second water outlet pipe. According to the utility model discloses hot water equipment has that the combustion noise is low, the complete machine is small, convenient to use is comfortable and combustion effect advantage such as good.

Description

Water heating device

Technical Field

The utility model relates to a hot water equipment makes technical field, particularly, relates to a hot water equipment.

Background

In the related art water heating apparatus, heat is generated by performing flame combustion using a mixed gas of gas and air to heat cold water flowing through the water heating apparatus into hot water. However, the combustion intensity of the gas is high, which causes the working noise of the water heating equipment to be high, and influences the use experience of users. Meanwhile, a large amount of harmful gases such as CO and NOx still exist in the combustion tail gas, and the environment-friendly effect of the hot water equipment is poor.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving one of the technical problem that exists among the prior art at least. Therefore, the utility model provides a hot water equipment, this hot water equipment have combustion noise low, the complete machine is small, convenient to use is comfortable and combustion effect advantage such as good.

To achieve the above object, an embodiment according to a first aspect of the present invention provides a water heating apparatus, including: a housing having an air inlet and an air outlet forming an air flow passage therebetween; a catalytic burner disposed at least partially within the gas flow passage and configured to perform catalytic combustion; a preheating burner disposed at least partially within the gas flow passage and for preheating the catalytic burner; the first heat exchanger is at least partially arranged in the airflow channel and is respectively communicated with a first water inlet pipe and a first water outlet pipe; and the second heat exchanger is arranged on the shell and is in thermal communication with the first water outlet pipe, and the second heat exchanger is respectively communicated with a second water inlet pipe and a second water outlet pipe.

According to the utility model discloses hot water equipment has advantages such as combustion noise is low, the complete machine is small, convenient to use is comfortable and combustion effect is good.

In addition, the water heating apparatus according to the above embodiment of the present invention may further have the following additional technical features:

according to some embodiments of the invention, in the direction of flow of the gas stream, the catalytic burner is located downstream of the preheating burner, the first heat exchanger is located downstream of the catalytic burner.

According to some embodiments of the invention, the water heating apparatus further comprises an ignition device, the ignition device being located at the preheating burner.

According to some embodiments of the present invention, the water heating apparatus further comprises a fan assembly, the fan assembly being disposed in the housing and located downstream of the first heat exchanger.

According to some embodiments of the invention, the water heating apparatus further comprises an outer casing, the outer casing being provided in the housing, the preheating burner the catalytic burner and at least one of the first heat exchangers being located in an inner side of the outer casing.

According to the utility model discloses a some embodiments, the second heat exchanger through first bypass water pipe respectively with first inlet tube with first outlet pipe links to each other.

According to some embodiments of the utility model, the hot water equipment still includes the switching-over valve, the switching-over valve has first switching-over state and second switching-over state, the switching-over valve is in during first switching-over state, first outlet pipe and hot water outlet intercommunication, the switching-over valve is in during second switching-over state, first outlet pipe passes through the second heat exchanger with first inlet tube intercommunication.

According to some embodiments of the present invention, the second heat exchanger is spaced apart from the first heat exchanger, and the second heat exchanger is located in a lower portion of the hot water apparatus.

According to the utility model discloses a some embodiments, first inlet tube with be connected with second bypass water pipe between the second inlet tube, second bypass water pipe is connected with the on-off valve.

According to some embodiments of the utility model, the below of first heat exchanger is provided with the water collector.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural view of a water heating apparatus according to an embodiment of the present invention.

Fig. 2 is a schematic structural view of a water heating apparatus according to another embodiment of the present invention.

Fig. 3 is a schematic structural view of a water heating apparatus according to another embodiment of the present invention.

Fig. 4 is a schematic structural view of a water heating apparatus according to another embodiment of the present invention.

Fig. 5 is a schematic structural view of a water heating apparatus according to another embodiment of the present invention.

Reference numerals: the water heater comprises a water heating device 1, a shell 100, a catalytic burner 200, a preheating burner 300, an ignition device 310, a first heat exchanger 400, a first water inlet pipe 410, a first water outlet pipe 420, a first bypass water pipe 430, a second bypass water pipe 440, a second heat exchanger 500, a second water inlet pipe 510, a second water outlet pipe 520, a fan assembly 610, an outer casing 620, a reversing valve 630, a gas proportional valve 640, a water pump 650, a third heat exchanger 700 and a water receiving disc 710.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

A water heating apparatus 1 according to an embodiment of the present invention is described below with reference to the accompanying drawings.

As shown in fig. 1 to 5, a water heating apparatus 1 according to an embodiment of the present invention includes a housing 100, a catalytic burner 200, a preheating burner 300, a first heat exchanger 400, and a second heat exchanger 500.

The housing 100 has an intake port and an exhaust port that form an airflow passage therebetween. A catalytic burner 200 is disposed at least partially within the gas flow passage and is used to perform catalytic combustion. A preheating burner 300 is at least partially provided within the gas flow channel and is used to preheat the catalytic burner 200. A first heat exchanger 400 is at least partially disposed within the airflow path, the first heat exchanger 400 being in communication with a first inlet tube 410 and a first outlet tube 420, respectively. The second heat exchanger 500 is disposed in the housing 100 and is in thermal communication with the first water outlet pipe 420, and the second heat exchanger 500 is in communication with the second water inlet pipe 510 and the second water outlet pipe 520, respectively.

Specifically, the first inlet pipe 410 is communicated with the first cold water inlet, and the first outlet pipe 420 is communicated with the first hot water outlet. The second inlet pipe 510 is communicated with the second cold water, and the second outlet pipe 520 is communicated with the second hot water outlet.

According to the water heating apparatus 1 of the embodiment of the present invention, by providing the catalytic burner 200 and the preheating burner 300, when the water heating apparatus 1 is operated, the catalytic combustor 200 may be heated by the heat radiated from the preheating combustor 300, so that the temperature of the catalytic combustor 200 is raised to within a suitable operating temperature range, in the working temperature range, the catalytic combustor 200 can perform the best catalytic combustion effect, the mixed gas of air and fuel gas is subjected to flameless catalytic combustion in the catalytic combustor 200, thus, the mixed gas can be more fully combusted, the combustion efficiency of the water heating equipment 1 is improved, the energy consumption of the water heating equipment 1 is reduced, meanwhile, harmful gases such as CO, NOx and the like generated due to insufficient combustion are greatly reduced, the environmental protection performance of the water heating equipment 1 is improved, flameless combustion is soft and stable, the noise is low, and the use comfort of users is convenient to improve.

In addition, by providing the first heat exchanger 400, the cold water flowing through the first heat exchanger 400 can be heated by the heat generated by the combustion of the mixed gas, so that the hot water apparatus 1 can be used to prepare hot water, the effect of preparing hot water by the hot water apparatus 1 is improved, the hot water apparatus 1 can supply hot water to the outside conveniently, and for example, the hot water apparatus 1 can be used to circularly supply heat to indoor heating equipment.

In addition, through setting up second heat exchanger 500, make second heat exchanger 500 and first outlet pipe 420 hot intercommunication, can utilize the hot water that produces in the first heat exchanger 400 to heat second heat exchanger 500 like this, be convenient for heat the cold water that flows through second heat exchanger 500 for hot water to make hot-water apparatus 1 can have two hot water export that hot water is independent, improve hot-water apparatus 1's performance, increase hot-water apparatus 1's application range. For example, the first outlet pipe 420 of the first heat exchanger 400 in the water heating device 1 can supply heat for indoor heating device circulation, and the second outlet pipe 520 of the second heat exchanger 500 can supply hot water for daily use of users.

In addition, the flameless combustion more fully releases the heat generated by the combustion of the gas, so that the heat released by the combustion of the gas with the same volume is higher, and a larger heat load can be generated on a smaller combustion area, so that the volume of the water heating equipment 1 can be reduced when the heat load is the same, and the space is saved for the installation of a user.

Therefore, according to the utility model discloses hot water equipment 1 has advantages such as the combustion noise is low, the complete machine is small, convenient to use is comfortable and combustion effect is good.

In some embodiments of the present invention, as shown in fig. 1-5, a water heating apparatus 1 according to embodiments of the present invention includes a housing 100, a catalytic burner 200, a preheating burner 300, a first heat exchanger 400, and a second heat exchanger 500.

Specifically, as shown in fig. 1 to 5, the catalytic combustor 200 is located downstream of the preheating combustor 300 and the first heat exchanger 400 is located downstream of the catalytic combustor 200 in the flow direction of the gas stream. So not only be convenient for utilize preheating burner 300 to heat catalytic combustor 200, improve preheating burner 300's preheating effect, be convenient for utilize the heat that the gas mixture burning produced to heat first heat exchanger 400 moreover to improve hot-water apparatus 1's complete machine performance, improve hot-water apparatus 1's the hydrothermal efficiency of preparation.

Optionally, as shown in fig. 1-5, the water heating apparatus 1 further comprises an ignition device 310, the ignition device 310 being located at the preheat burner 300. In this way, the ignition device 310 may be used to ignite the preheating burner 300, so that the mixed gas may be combusted by the preheating burner 300 to generate heat, thereby ensuring the heating reliability and stability of the preheating burner 300.

Specifically, as shown in fig. 1 to 5, the water heating apparatus 1 further includes a fan assembly 610, and the fan assembly 610 is disposed in the casing 100 and located downstream of the first heat exchanger 400. In this way, the fan assembly 610 can be used to drive the air to flow in the air flow channel, so as to improve the combustion efficiency and the heating efficiency of the water heating apparatus 1, and thus improve the ability of the water heating apparatus 1 to prepare hot water.

More specifically, the fan assembly 610 may employ a variable frequency fan or a variable speed fan. Therefore, the load regulation ratio is larger, the lowest load is lower, the lowest temperature rise is lower, and the water comfort level of a user in summer is further improved.

Optionally, as shown in fig. 1 to 5, the water heating apparatus 1 further includes an outer casing 620, the outer casing 620 being disposed inside the housing 100, and at least one of the preheating burner 300, the catalytic burner 200 and the first heat exchanger 400 being located inside the outer casing 620. This facilitates the formation of the air flow passage for smooth air flow in the water heating apparatus 1.

In some embodiments, the preheat burner 300, the catalytic burner 200, and the first heat exchanger 400 are all located inside the outer casing 620.

Alternatively, the second heat exchanger 500 is connected to the first water inlet pipe 410 and the first water outlet pipe 420 through the first bypass water pipe 430, respectively. This allows a heat exchange circuit to be formed between the first heat exchanger 400 and the second heat exchanger 500, which facilitates the circulation of water between the first heat exchanger 400 and the second heat exchanger 500.

Specifically, as shown in fig. 1 to 5, a first bypass water pipe 430 is connected between the first water inlet pipe 410 and the first water outlet pipe 420, and the first bypass water pipe 430 is in thermal communication with the second heat exchanger 500. This allows a circulation loop to be formed between the first water inlet pipe 410, the first water outlet pipe 420 and the first heat exchanger 400, so that the second heat exchanger 500 is heated by the hot water generated in the first heat exchanger 400.

More specifically, as shown in fig. 1 to 5, the hot water apparatus 1 further includes a direction changing valve 630, the direction changing valve 630 has a first direction changing state and a second direction changing state, when the direction changing valve 630 is in the first direction changing state, the first water outlet pipe 420 is communicated with the hot water outlet, and when the direction changing valve 630 is in the second direction changing state, the first water outlet pipe 420 is communicated with the first water inlet pipe 410 through the second heat exchanger 500. Specifically, the hot water outlet is the first hot water outlet. Thus, when the direction changing valve 630 is in the first direction changing state, the hot water generated in the first heat exchanger 400 can be supplied to the outside through the first water outlet pipe 420, and when the direction changing valve 630 is in the second direction changing state, a circulation loop can be formed among the first water inlet pipe 410, the first water outlet pipe 420 and the first heat exchanger 400, so that the hot water generated in the first heat exchanger 400 can heat the second heat exchanger 500, and the functionality and the applicability of the hot water apparatus 1 can be improved.

In some embodiments, when the direction valve 630 is in the first direction state, the first outlet pipe 420 is connected to the hot water outlet and disconnected from the first bypass pipe 430, and when the direction valve 630 is in the second direction state, the first outlet pipe 420 is disconnected from the hot water outlet and connected to the first bypass pipe 430. Specifically, the hot water outlet is the first hot water outlet.

Optionally, the second heat exchanger 500 is spaced apart from the first heat exchanger 400, and the second heat exchanger 500 is located at a lower portion of the water heating apparatus 1. This facilitates a rapid delivery of the heated water stream in the second heat exchanger 500 to the hot water appliance 1.

Alternatively, as shown in fig. 1 to 5, a second bypass water pipe 440 is connected between the first inlet pipe 410 and the second inlet pipe 510, and the second bypass water pipe 440 is connected with an on-off valve. Therefore, cold water can be allowed to flow between the first water inlet pipe 410 and the second water inlet pipe 510, for example, when the cold water inlet of the first water inlet pipe 410 is the water return opening of an indoor heating device, the second water inlet pipe 510 can be used for supplementing water to the first water inlet pipe 410, sufficient cold water can be ensured to flow into the first water inlet pipe 410, the reliability of hot water preparation of the hot water device 1 is ensured, and the working reliability and stability of the hot water device 1 are improved.

Optionally, a water pan 710 is disposed below the first heat exchanger 400. Therefore, the water receiving tray 710 can be used for collecting the condensed water attached to the first heat exchanger 400, and the condensed water can be conveniently and intensively treated and discharged.

In other embodiments of the present invention, as shown in fig. 5, the water heating apparatus 1 further comprises a third heat exchanger 700, and the third heat exchanger 700 is located downstream of the first heat exchanger 400 in the flow direction of the gas. Specifically, the third heat exchanger 700 may be a condensing heat exchanger that heats cold water flowing through the inside thereof using condensation heat release of steam. Therefore, the energy in the combustion waste gas can be fully utilized, the heating efficiency of the water heating equipment 1 is improved, the energy consumption of the water heating equipment 1 is reduced, and the environmental protection performance of the water heating equipment 1 is improved.

Specifically, as shown in fig. 5, a water pan 710 is disposed below the third heat exchanger 700. Therefore, the water receiving tray 710 can be used for collecting the condensed water attached to the third heat exchanger 700, and the condensed water can be conveniently and intensively treated and discharged.

Optionally, the third heat exchanger 700 is integrated with the first heat exchanger 400. Therefore, the first heat exchanger 400 and the third heat exchanger 700 form a heat exchange module, the integration level of the hot water device 1 is improved, and the assembly efficiency of the hot water device 1 is improved.

Specifically, the water heating apparatus 1 is a wall-hanging stove. That is, the water heating apparatus 1 may be a gas heating water heater. Therefore, the combustion efficiency of the mixed gas in the wall-hanging stove can be improved, the water supply diversity of the wall-hanging stove is increased, and the overall performance of the water heating equipment 1 is improved.

In some embodiments of the present invention, the water heating apparatus 1 is a forced-pumping type direct-fired flameless combustion wall-mounted boiler. In other words, the water heating apparatus 1 is a strong pumping type direct combustion flameless combustion gas-fired heating water heater. It is to be understood here that "normal combustion" means that air enters from the lower part of the water heating apparatus 1 and exits from the upper part of the water heating apparatus 1. By "pumping" is meant that the fan assembly 610 is disposed proximate to the outlet of the hot water appliance 1. Therefore, the hot water equipment 1 can save energy, reduce emission, reduce noise and reduce the volume of the whole machine. The hot water device 1 adopts a flameless catalytic combustion mode to control the generation of CO/NOx from the source. Under the action of the catalyst, the fuel gas can fully react and burn, harmful gas generated by burning can be effectively reduced, flameless combustion is soft and stable, the noise is low, and the water heating equipment 1 is more environment-friendly, safe and comfortable to use.

Specifically, the water heating apparatus 1 includes two independent combustion platforms, namely, a catalytic combustor 200 and a preheating combustor 300, and the water heating apparatus 1 further includes an ignition device 310, a first heat exchanger 400 disposed above the catalytic combustor 200, a fan assembly 610, a water inlet and outlet device, a second heat exchanger 500, a reversing valve 630, a circulating water pump, an expansion tank, and a gas proportional valve 640 for connecting a water outlet return pipe and performing gas regulation.

Specifically, the outer housing 620 includes a gas mixing chamber, and the gas enters the outer housing 620 through the gas proportional valve 640, where the gas mixing chamber is mixed with the air, and then the mixed gas enters the preheating burner 300 and the catalytic burner 200 for combustion, and the combusted flue gas heats the heating water through the first heat exchanger 400, and the exhaust gas is then discharged through the fan assembly 610.

When the water heating apparatus 1 is in a heating state, heated heating water in the first heat exchanger 400 passes through the reversing valve 630 and enters the room heat dissipation system through the heating water outlet, and in this state, the circulating water pump 650 supplies power to the heating water.

When the hot water apparatus 1 is in a bathroom state, the heated heating water in the first heat exchanger 400 passes through the reversing valve 630, then flows through the second heat exchanger 500 and the circulating water pump 650, and then flows back to the first heat exchanger 400 to be heated again; in this process, the bath water enters the second heat exchanger 500 through the cold water inlet to exchange heat with the heating water, and then flows out through the hot water outlet.

The utility model discloses in, preheating burner 300 and catalytic combustor 200 are two independent detached burning platforms, and the gas can realize abundant burning in preheating burner 300 and catalytic combustor 200, makes produced CO and NOX content further reduce after the burning. And the catalytic combustion is flameless combustion, the combustion reaction is soft and stable, and the combustion noise generated when the wall-mounted furnace with open flame works is reduced, so that the noise generated when the wall-mounted furnace runs is lower. In addition, flameless combustion is the combination of radiation heat exchange and convection heat exchange, so that the heat exchange effect is better and the energy is saved. The first heat exchanger 400 is made of stainless steel or other high temperature resistant material.

Optionally, a third heat exchanger 700 may be added to the water heating device 1, and the heat is absorbed more fully by using the principle of water vapor condensation heat release, so that the energy efficiency can reach one level or higher. And the structure is added with a condensed water collecting device, namely a water receiving tray 710, the condensed water is discharged through a condensed water outlet, and the internal structure of the water heating equipment 1 is more universal.

Further, the third heat exchanger 700 is located directly above the first heat exchanger 400.

In other embodiments of the present invention, the water heater 1 may be an inverted combustion type wall-hanging stove, i.e. air enters from the upper part of the water heater 1 and then exits from the lower part of the water heater. This makes it easier to drain the condensed water. The air intake form of the water heating apparatus 1 may be a blower, i.e., the blower assembly 610 is disposed near the air intake. So that the resistance of the water heating device 1 is stronger.

According to one embodiment of the present invention, the water heating apparatus 1 includes a housing 100, a catalytic burner 200, a preheating burner 300, a first heat exchanger 400, and a second heat exchanger 500. The housing 100 has an intake port and an exhaust port that form an airflow passage therebetween. A catalytic burner 200 is disposed at least partially within the gas flow passage and is used to perform catalytic combustion. A preheating burner 300 is at least partially provided within the gas flow channel and is used to preheat the catalytic burner 200. A first heat exchanger 400 is at least partially disposed within the airflow path, the first heat exchanger 400 being in communication with a first inlet tube 410 and a first outlet tube 420, respectively. The second heat exchanger 500 is disposed in the housing 100 and is in thermal communication with the first water outlet pipe 420, and the second heat exchanger 500 is in communication with the second water inlet pipe 510 and the second water outlet pipe 520, respectively.

In the flow direction of the gas stream, the catalytic combustor 200 is located downstream of the preheating combustor 300, and the first heat exchanger 400 is located downstream of the catalytic combustor 200. The water heating device 1 further comprises an ignition device 310, the ignition device 310 being located at the preheating burner 300. The water heating apparatus 1 further comprises a fan assembly 610, the fan assembly 610 being disposed within the housing 100 and downstream of the first heat exchanger 400. The fan assembly 610 may employ a variable frequency fan or a variable speed fan. The water heating apparatus 1 further includes an outer casing 620, the outer casing 620 being disposed inside the housing 100, and the preheating burner 300, the catalytic burner 200 and the first heat exchanger 400 being located inside the outer casing 620.

A first bypass water pipe 430 is connected between the first water inlet pipe 410 and the first water outlet pipe 420, and the first bypass water pipe 430 is thermally communicated with the second heat exchanger 500. The hot water apparatus 1 further includes a direction valve 630, the direction valve 630 has a first direction state and a second direction state, when the direction valve 630 is in the first direction state, the first water outlet pipe 420 is communicated with the hot water outlet and disconnected from the first bypass water pipe 430, and when the direction valve 630 is in the second direction state, the first water outlet pipe 420 is disconnected from the hot water outlet and communicated with the first bypass water pipe 430. A second bypass water pipe 440 is connected between the first water inlet pipe 410 and the second water inlet pipe 510, and the second bypass water pipe 440 is connected with an on-off valve.

The water heating apparatus 1 further comprises a third heat exchanger 700, the third heat exchanger 700 being located downstream of the first heat exchanger 400 in the flow direction of the gas. A water pan 710 is disposed below the third heat exchanger 700. The third heat exchanger 700 is integrated with the first heat exchanger 400.

Other constructions and operations of the water heating apparatus 1 according to the embodiment of the present invention are known to those skilled in the art and will not be described in detail herein.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship indicated based on the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention. Furthermore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified. In the description of the present invention, the first feature "on" or "under" the second feature may include the first and second features being in direct contact, and may also include the first and second features being in contact with each other not directly but through another feature therebetween.

In the description of the invention, the first feature being "on", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A water heating apparatus, comprising:

a housing having an air inlet and an air outlet forming an air flow passage therebetween;

a catalytic burner disposed at least partially within the gas flow passage and configured to perform catalytic combustion;

a preheating burner disposed at least partially within the gas flow passage and for preheating the catalytic burner;

the first heat exchanger is at least partially arranged in the airflow channel and is respectively communicated with a first water inlet pipe and a first water outlet pipe;

and the second heat exchanger is arranged on the shell and is in thermal communication with the first water outlet pipe, and the second heat exchanger is respectively communicated with a second water inlet pipe and a second water outlet pipe.

2. The water heating apparatus according to claim 1, wherein the catalytic burner is located downstream of the preheating burner and the first heat exchanger is located downstream of the catalytic burner in a flow direction of the gas stream.

3. The water heater apparatus according to claim 1, further comprising an ignition device located at the preheat burner.

4. The water heater apparatus of claim 1, further comprising a fan assembly disposed within the housing downstream of the first heat exchanger.

5. The water heater according to claim 1, further comprising an outer shell disposed within the housing, at least one of the preheat burner, the catalytic burner, and the first heat exchanger being located inside the outer shell.

6. The water heating apparatus according to claim 1, wherein the second heat exchanger is connected to the first inlet pipe and the first outlet pipe through a first bypass water pipe, respectively.

7. The water heating apparatus according to claim 6, further comprising a direction valve having a first direction state and a second direction state, wherein the first outlet pipe communicates with the hot water outlet when the direction valve is in the first direction state, and wherein the first outlet pipe communicates with the first inlet pipe through the second heat exchanger when the direction valve is in the second direction state.

8. The water heating apparatus according to claim 1, wherein the second heat exchanger is spaced apart from the first heat exchanger, and the second heat exchanger is located at a lower portion of the water heating apparatus.

9. The water heater according to claim 1, wherein a second bypass water pipe is connected between the first inlet pipe and the second inlet pipe, and the second bypass water pipe is connected with a cut-off valve.

10. The water heating apparatus according to claim 1, wherein a water pan is disposed below the first heat exchanger.