CN212566263U - Gas water heater - Google Patents

Abstract

The utility model relates to a kitchen appliance technical field, concretely relates to gas heater, include: the heat exchanger comprises a heat exchange tube, one end of the heat exchange tube is communicated with a water inlet of the gas water heater, and the other end of the heat exchange tube is communicated with a water outlet of the gas water heater; the heating device is arranged on the heat exchange tube; the first anti-freezing device is arranged at the water inlet and is suitable for starting an anti-freezing mode when the heating device fails to prevent freezing; the second anti-freezing device is arranged at the water outlet and is suitable for starting an anti-freezing mode when the heating device fails in an anti-freezing mode. Through setting up first freeze-proof device and second freeze-proof device in gas heater's water inlet and delivery port department, can start the mode of preventing frostbite when heating device's anti-freezing function became invalid, with the outflow of depositing water in the heat exchange tube, prevent to deposit the long-pending of water in the heat exchange tube and stay, when the temperature is lower, lead to the heat exchange tube frost crack and leak, the heat exchange tube is difficult by freezing when having guaranteed the heating to prevent frostbite and become invalid.

Description

Gas water heater

Technical Field

The utility model relates to a kitchen appliance technical field, concretely relates to gas heater.

Background

The gas water heater has become an indispensable kitchen life electrical appliance of modern families, and provides a water heater required by life for people. However, in winter, especially in most northern areas, winter temperatures are generally below 0 ℃. When the gas water heater is in a non-working state and the waterway system is full of cold water, the whole gas water heater is arranged outside a balcony or external cold air flows through the smoke exhaust pipe to form backflow, so that the internal temperature of the water heater suddenly drops, the pipeline freezes and expands, the pipeline is very easy to freeze and leak, and economic loss of users is caused.

In the prior art, the gas water heater is usually prevented from being frozen by additionally arranging electric auxiliary heating outside a heat exchanger of the gas water heater, but a heating wire and a ceramic body are easily damaged and have short service life under the low temperature of the electric auxiliary heating, and once the electric auxiliary heating is prevented from being frozen and losing efficacy, the heat exchanger still has the phenomenon that a heat exchange pipe is frozen and damaged below 0 ℃, and cannot be normally used.

SUMMERY OF THE UTILITY MODEL

Therefore, the to-be-solved technical problem of the utility model lies in overcoming the gas heater among the prior art and being easily by the defect of freezing under the condition of the frostproofing inefficacy of electric auxiliary heating to a gas heater that the heat exchange tube is difficult by freezing under the condition of the frostproofing inefficacy of electric auxiliary heating is provided.

In order to solve the technical problem, the utility model provides a gas water heater, include:

the heat exchanger comprises a heat exchange tube, one end of the heat exchange tube is communicated with a water inlet of the gas water heater, and the other end of the heat exchange tube is communicated with a water outlet of the gas water heater;

the heating device is arranged on the heat exchange tube;

the first anti-freezing device is arranged at the water inlet, has an anti-freezing mode and a water inlet mode, and is suitable for starting the anti-freezing mode to flow out the stored water in the heat exchange pipe when the heating device fails to prevent freezing;

and/or the presence of a gas in the gas,

the second anti-freezing device is arranged at the water outlet, has an anti-freezing mode and a water outlet mode, and is suitable for starting the anti-freezing mode to enable the stored water in the heat exchange pipe to flow out when the heating device fails in anti-freezing mode.

Further, the first anti-freeze apparatus includes:

the water inlet main channel is suitable for enabling the first anti-freezing device to be in a water inlet mode when the water inlet main channel is opened;

one end of the first bypass channel is communicated with the water inlet main channel and is suitable for enabling the first anti-freezing device to be in an anti-freezing mode when the first bypass channel is opened;

the first antifreezing valve is arranged on the main water inlet channel and/or the first bypass channel and is suitable for controlling the opening and closing of the main water inlet channel and the first bypass channel;

and/or the presence of a gas in the gas,

the second anti-freeze apparatus includes:

the main water outlet channel is suitable for enabling the second anti-freezing device to be in a water outlet mode when the main water outlet channel is opened;

one end of the second bypass channel is communicated with the main water outlet channel and is suitable for enabling the second anti-freezing device to be in an anti-freezing mode when the second bypass channel is opened;

and the second antifreezing valve is arranged on the main water outlet channel and/or the second bypass channel and is suitable for controlling the opening and closing of the main water outlet channel and the second bypass channel.

Further, the first antifreeze valve includes:

the water inlet valve is arranged on the water inlet main channel and is suitable for controlling the opening and closing of the water inlet main channel;

the first discharge valve is arranged on the first bypass channel and is suitable for controlling the opening and closing of the first bypass channel;

and/or the presence of a gas in the gas,

the second anti-freeze valve includes:

and the second discharge valve is arranged on the second bypass channel and is suitable for controlling the opening and closing of the second bypass channel.

Further, the first anti-freeze valve and/or the second anti-freeze valve are solenoid valves.

Further, the first freeze protection device and/or the second freeze protection device are/is arranged below the heat exchanger.

Further, the gas water heater further includes: and the control device is connected with the heating device, the first anti-freezing device and/or the second anti-freezing device and is suitable for controlling the heating device, the first anti-freezing device and/or the second anti-freezing device to start an anti-freezing mode.

Further, the gas water heater further includes:

the temperature detection device is arranged at the position, close to the water inlet, of the heat exchange tube, the temperature detection device is connected with the control device and suitable for controlling the first anti-freezing device and the second anti-freezing device to be in an anti-freezing mode when the detection value of the temperature detection device is smaller than or equal to the preset temperature and the heating device is in an anti-freezing failure state.

Further, the gas water heater further includes:

and the timing device is connected with the control device and is suitable for starting timing when the detection value of the temperature detection device is less than or equal to the preset temperature, the timing time of the timing device lasts for a first preset time, and the detection value of the temperature detection device is still less than or equal to the preset temperature, namely the heating device is in anti-freezing failure.

Further, when the detection value of the temperature detection device is larger than the preset temperature, the control device controls the first anti-freezing device to be in a water inlet mode, the second anti-freezing device to be in a water outlet mode, and the heating device is turned off.

Further, the preset temperature is 5 ℃.

Further, the gas water heater further includes:

the check valve is arranged in a smoke pipe of the gas water heater and is suitable for preventing outside air from entering the gas water heater.

The utility model discloses technical scheme has following advantage:

1. the utility model provides a gas water heater, through setting up heating device on gas water heater's heat exchange tube, can realize the function of preventing frostbite to the heat transfer tube, water inlet and/or delivery port department through at gas water heater set up first freeze-proof device and second freeze-proof device, can be when heating device's freeze-proof function became invalid, start the freeze-proof mode, with depositing the outflow of depositing water in the heat transfer tube, prevent to deposit the long-pending of water in the heat transfer tube and stay, when the temperature is lower, lead to the heat transfer tube frost crack and leak, the heat transfer tube is difficult for being frozen out when having guaranteed the heating freeze-proof inefficacy.

2. The utility model provides a gas water heater through setting up first freeze-proof device to including the main entrance that intakes, first bypass passageway and first frost valve, and second freeze-proof device sets up to including play water main entrance, second bypass passageway and second frost valve for first freeze-proof device and second freeze-proof device can enough play the function of intaking, play water, can realize preventing frostbite when heating device became invalid again, and the structure is simpler.

3. The utility model provides a gas water heater sets up to the solenoid valve through with first frost valve and/or second frost valve for the different modes of first frost valve and second frost valve can automatic switch, and it is more convenient to control.

4. The utility model provides a gas water heater is through locating heat exchanger's below with first freeze-proof device and second freeze-proof device for when getting rid of depositing water in the heat transfer pipe through first freeze-proof device and second freeze-proof device, can rely on gravity to carry out the drainage, the drainage is cleaner, prevents remaining of cold water.

5. The utility model provides a gas water heater, through setting up temperature-detecting device, timing device and controlling means, can be according to temperature-detecting device's detected value automated inspection temperature of intaking, and can judge automatically whether heating device has appeared freezing failure through the timing time, and then the first freeze-proof device of controlling means automatic control and second freeze-proof device open the freeze-proof mode, and degree of automation is higher.

6. The utility model provides a gas water heater through set up the check valve in gas water heater's tobacco pipe, can prevent that external low temperature air from getting into gas water heater, prevents the refrigeration effect of external low temperature air aggravation heat exchange tube, further prevents that the heat exchange tube from being frozen bad.

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 embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural view of a gas water heater according to the present invention in normal operation;

FIG. 2 is a schematic structural view of the gas water heater of the present invention during freezing protection;

FIG. 3 is a cross-sectional view of the second anti-freeze apparatus of the gas water heater of the present invention in the water-out mode;

FIG. 4 is a cross-sectional view of the second anti-freeze apparatus of the gas water heater of the present invention in an anti-freeze mode;

FIG. 5 is a cross-sectional view of the first anti-freeze apparatus of the gas water heater of the present invention in a water intake mode;

fig. 6 is a cross-sectional view of the first anti-freezing device of the gas water heater in anti-freezing mode.

Description of reference numerals:

1-a heat exchanger; 2-a heating device; 3-a main water inlet channel; 4-a first bypass channel; 5-a water inlet valve; 6-a first relief valve; 7-a main water outlet channel; 8-a second bypass channel; 9-a second relief valve; 10-a control device; 11-temperature detection means; 12-a one-way valve; 13-heat exchange tube; 14-a first anti-freeze device; 15-second antifreeze device.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

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.

Furthermore, the technical features mentioned in the different embodiments of the invention described below can be combined with each other as long as they do not conflict with each other.

As shown in fig. 1 to 6, the present embodiment provides a gas water heater, including: the heat exchanger 1 comprises a heat exchange tube 13, one end of the heat exchange tube 13 is communicated with a water inlet of the gas water heater, and the other end of the heat exchange tube 13 is communicated with a water outlet of the gas water heater; the heating device 2 is arranged on the heat exchange tube 13; the first anti-freezing device 14 is arranged at the water inlet, has an anti-freezing mode and a water inlet mode, and is suitable for starting the anti-freezing mode by the first anti-freezing device 14 to flow out the stored water in the heat exchange pipe 13 when the heating device 2 fails to prevent freezing; the second anti-freezing device 15 is arranged at the water outlet, has an anti-freezing mode and a water outlet mode, and is suitable for starting the anti-freezing mode by the second anti-freezing device 15 when the heating device 2 fails in an anti-freezing mode, so that the stored water in the heat exchange tube 13 flows out.

Through set up heating device 2 on gas heater's heat exchange tube 13, can realize the function of preventing frostbite to heat exchange tube 13, water inlet and delivery port department through at gas heater set up first freeze-proof device 14 and second freeze-proof device 15 respectively, can be when heating device 2's freeze-proof function became invalid, start the mode of preventing frostbite, regardless of deposit water in the heat exchange tube 13 that is close to the delivery port like this or the deposit water homoenergetic that is close to the heat exchange tube 13 of water inlet flows completely, prevent to deposit the long-pending of deposit water in heat exchange tube 13, when the temperature is lower, lead to heat exchange tube 13 frost crack and leak, heat exchange tube 13 is difficult to be frozen out when having guaranteed the heating freeze-proof to become.

The specific form of the heating device 2 is various, and as shown in fig. 1 and 2, the heating device 2 in this embodiment is a heating wire disposed on the outer surface of the heat exchange pipe 13. Specifically, three heating wires may be provided at intervals along the extending direction of the heat exchange tube 13, for example, one is provided outside the heat exchange tube 13 near the water inlet, one is provided in the middle of the heat exchange tube 13, and one is provided outside the heat exchange tube 13 near the water outlet, but more heating wires may be provided. As an alternative embodiment, the heating device 2 may be a heating pipe.

As an alternative embodiment, the first antifreeze device 14 may be provided only at the water inlet, or the second antifreeze device 15 may be provided only at the water outlet, as long as the stored water in the heat exchange pipe 13 can be discharged.

As shown in fig. 5 and 6, the first antifreeze device 14 includes: a main water intake channel 3 adapted to put the first antifreeze device 14 in a water intake mode when opened; a first bypass passage 4 having one end communicating with the main water inlet passage 3 and the other end communicating with the outside, adapted to put the first antifreeze device 14 in an antifreeze mode when opened, and discharging the water stored in the heat exchange tube 13 to the outside, such as a sewer, through the first bypass passage 4; and the first antifreezing valve is arranged at the joint of the main water inlet channel 3 and the first bypass channel 4 and is suitable for controlling the opening and closing of the main water inlet channel 3 and the first bypass channel 4.

As shown in fig. 3 and 4, the second antifreeze apparatus 15 includes: a main water outlet channel 7 adapted to put the second anti-freeze apparatus 15 in a water outlet mode when opened; a second bypass channel 8, one end of which is communicated with the main water outlet channel 7 and the other end of which is communicated with the outside, and is suitable for enabling the second anti-freezing device 15 to be in an anti-freezing mode when being opened, and discharging the water stored in the heat exchange tube 13 to the outside through the first bypass channel 4, such as a lower water channel; and the second antifreezing valve is arranged at the joint of the main water outlet channel 7 and the second bypass channel 8 and is suitable for controlling the opening and closing of the main water outlet channel 7 and the second bypass channel 8.

The first anti-freezing device 14 comprises the water inlet main channel 3, the first bypass channel 4 and the first anti-freezing valve, and the second anti-freezing device 15 comprises the water outlet main channel 7, the second bypass channel 8 and the second anti-freezing valve, so that the first anti-freezing device 14 and the second anti-freezing device 15 can play a role in water inlet and outlet, can prevent freezing when the heating device 2 fails, and is simple in structure.

Since the main water inlet channel 3 of the gas water heater is always in an open state, the first anti-freeze valve may be set to include: the water inlet valve 5 is arranged on the water inlet main channel 3 and is suitable for controlling the opening and closing of the water inlet main channel 3; and a first relief valve 6 provided on the first bypass passage 4 and adapted to control opening and closing of the first bypass passage 4. As an alternative embodiment, the first antifreeze valve may be a three-way valve.

Specifically, as shown in fig. 5 and 6, the first anti-freezing device 14 includes a main water inlet channel 3, a water inlet valve 5 is disposed on the main water inlet channel 3, a first bypass channel 4 is connected to the main water inlet channel 3 above the water inlet valve 5, and a first relief valve 6 is disposed at a connection between the first bypass channel 4 and the main water inlet channel 3, in a water inlet mode, the water inlet valve 5 is opened, the first relief valve 6 is closed, in an anti-freezing mode, the water inlet valve 5 is closed, and the first relief valve 6 is opened.

Since the main water outlet channel 7 of the gas water heater is opened and closed by the user, the main water outlet channel 7 is opened when the user uses the gas water heater, and the main water outlet channel 7 is closed when the user does not use the gas water heater, and since the gas water heater needs to be protected from freezing, it is inevitable that the user does not use the gas water heater, as shown in fig. 3 and 4, the second anti-freezing valve may include: the second relief valve 9 is arranged on the second bypass channel 8 and is suitable for controlling the opening and closing of the second bypass channel 8, two valves are not needed to be arranged on the first antifreezing valve, and the structure is simple. As an alternative embodiment, the second antifreeze valve may be provided with a similar structure to the first antifreeze valve, including two valves, or may be provided as a three-way valve.

In order to realize the automatic switching of different modes of the first antifreezing valve and the second antifreezing valve and facilitate the control, the first antifreezing valve and the second antifreezing valve can be set as electromagnetic valves. As an alternative embodiment, the first antifreeze valve and the second antifreeze valve may be manually opened and closed valves.

The first antifreeze device 14 and the second antifreeze device 15 in the present embodiment are provided below the heat exchanger 1. By providing the first antifreeze device 14 and the second antifreeze device 15 below the heat exchanger 1, when water stored in the heat exchange pipe 13 is discharged through the first antifreeze device 14 and the second antifreeze device 15, the water can be discharged by gravity, the water can be discharged more cleanly, and cold water can be prevented from remaining. As an alternative embodiment, the first antifreeze device 14 and the second antifreeze device 15 may be provided above the heat exchanger 1, or the first antifreeze device 14 may be provided above the heat exchanger 1 and the second antifreeze device 15 may be provided below the heat exchanger 1, or the first antifreeze device 14 may be provided below the heat exchanger 1 and the second antifreeze device 15 may be provided above the heat exchanger 1.

As shown in fig. 1 and 2, the gas water heater further includes: the control device 10 is connected with the heating device 2, the first antifreezing device 14 and the second antifreezing device 15 and is suitable for controlling the heating device 2, the first antifreezing device 14 and the second antifreezing device 15 to start an antifreezing mode. As an alternative embodiment, the user may manually operate the heating device 2, the first antifreeze device 14, and the second antifreeze device 15 to be turned on or off without providing the control device 10.

The gas heater still includes: the temperature detection device 11 is arranged at the position, close to the water inlet, of the heat exchange pipe 13, the temperature detection device 11 is connected with the control device 10, and the control device 10 is suitable for controlling the first anti-freezing device 14 and the second anti-freezing device 15 to be in an anti-freezing mode when the detection value of the temperature detection device 11 is smaller than or equal to a preset temperature and the heating device 2 is in anti-freezing failure; when the detection value of the temperature detection device 11 is greater than the preset temperature, the control device 10 controls the first anti-freezing device 14 to be in the water inlet mode, the second anti-freezing device 15 to be in the water outlet mode, and the heating device 2 is turned off, so that the heat exchange pipe 13 does not need to be anti-frozen. Specifically, the temperature detection device 11 is a bulb. As an alternative embodiment, the temperature detection device 11 may be a temperature detector.

The gas heater still includes: and the timing device is connected with the control device 10 and is suitable for starting timing when the detection value of the temperature detection device 11 is less than or equal to the preset temperature, the timing time of the timing device lasts for a first preset time, and the detection value of the temperature detection device 11 is still less than or equal to the preset temperature, namely the heating device 2 is in anti-freezing failure. Specifically, the timing device is a timer.

Through setting up temperature-detecting device 11, timing device and controlling means 10, can be according to the detected value automated inspection temperature of temperature-detecting device 11, and can judge automatically whether heating device 2 has appeared preventing frostbite inefficacy through the timing time, and then controlling means 10 automatic control first freeze-proof device 14 and second freeze-proof device 15 open the mode of preventing frostbite, and degree of automation is higher.

Specifically, the preset temperature is set to 5 ℃ and the first preset time is set to 2 min. Of course, the preset temperature may be set to any temperature of 2 ℃ to 8 ℃, and the first preset time may be set to any time of 1min to 3min, without any limitation.

The gas heater still includes: the check valve 12 is arranged in a smoke pipe of the gas water heater and is suitable for preventing outside air from entering the gas water heater. Through set up check valve 12 in gas heater's tobacco pipe, can prevent that external low temperature air from getting into gas heater, prevent that external low temperature air from aggravating the refrigeration effect of heat exchange tube 13, further prevent that heat exchange tube 13 from being frozen.

As shown in fig. 1, when the gas water heater is in normal operation, that is, the detection value of the temperature detection device 11 is greater than 5 ℃, the heating device 2 is turned off, the first anti-freezing device 14 is in the water inlet mode, that is, used as a water inlet joint of the gas water heater, and the second anti-freezing device is in the water outlet mode, that is, used as a water outlet joint of the gas water heater. As shown in fig. 2, when the gas water heater is turned off and needs to be anti-frozen, the check valve 12 in the flue pipe is always in an open state, when the detection value of the temperature detection device 11 is less than or equal to 5 ℃, the control device 10 firstly controls the heating device 2 to be opened, the first anti-freezing device 14 is in a water inlet mode, the second anti-freezing mode is in a water outlet mode, the heating device 2 directly heats the heat exchange pipe 13 to prevent the water stored in the heat exchange pipe 13 from freezing, when the detection value of the temperature detection device 11 is still less than or equal to 5 ℃ after lasting for a first preset time, the heating device 2 fails, normal anti-freezing of the heat exchange pipe 13 cannot be performed, at this time, the control device 10 controls the first anti-freezing device 14 and the second anti-freezing device 15 to be in the anti-freezing mode, the first relief valve 6 and the second relief valve 9 are both in an open state, so that the water stored in the heat exchange pipe 13 can flow out from the first, at the moment, the gas water heater does not have cold water inlet or cold water residue, so that the heat exchange tube 13 is not frozen due to freezing, the possibility of damaging the gas water heater is further avoided, the gas water heater is still not easy to freeze under the condition that the heating device 2 is prevented from freezing and losing efficacy, and the service life of the gas heat exchanger is prolonged.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications can be made without departing from the scope of the invention.

Claims (11)

1. A gas water heater, comprising:

the heat exchanger (1) comprises a heat exchange pipe (13), one end of the heat exchange pipe (13) is communicated with a water inlet of the gas water heater, and the other end of the heat exchange pipe (13) is communicated with a water outlet of the gas water heater;

the heating device (2) is arranged on the heat exchange tube (13);

the first anti-freezing device (14) is arranged at the water inlet, has an anti-freezing mode and a water inlet mode, and is suitable for starting the anti-freezing mode of the first anti-freezing device (14) to flow out stored water in the heat exchange pipe (13) when the heating device (2) fails in anti-freezing;

and/or the presence of a gas in the gas,

and the second anti-freezing device (15) is arranged at the water outlet, has an anti-freezing mode and a water outlet mode, is suitable for starting the anti-freezing mode of the second anti-freezing device (15) when the heating device (2) is in anti-freezing failure, and enables the stored water in the heat exchange tube (13) to flow out.

2. Gas water heater according to claim 1, characterized in that said first anti-freeze device (14) comprises:

-a main water intake channel (3) adapted to put said first antifreeze device (14) in a water intake mode when open;

a first bypass channel (4), one end of which is communicated with the water inlet main channel (3) and is suitable for enabling the first anti-freezing device (14) to be in an anti-freezing mode when the first bypass channel is opened;

the first antifreezing valve is arranged on the main water inlet channel (3) and/or the first bypass channel (4) and is suitable for controlling the opening and closing of the main water inlet channel (3) and the first bypass channel (4);

and/or the presence of a gas in the gas,

the second freeze protection device (15) comprises:

-a main water outlet channel (7) adapted to put the second anti-freeze device (15) in a water outlet mode when opened;

one end of the second bypass channel (8) is communicated with the main water outlet channel (7) and is suitable for enabling the second anti-freezing device (15) to be in an anti-freezing mode when the second bypass channel is opened;

and the second antifreezing valve is arranged on the main water outlet channel (7) and/or the second bypass channel (8) and is suitable for controlling the opening and closing of the main water outlet channel (7) and the second bypass channel (8).

3. The gas water heater of claim 2, wherein the first anti-freeze valve comprises:

the water inlet valve (5) is arranged on the water inlet main channel (3) and is suitable for controlling the opening and closing of the water inlet main channel (3);

the first relief valve (6) is arranged on the first bypass channel (4) and is suitable for controlling the opening and closing of the first bypass channel (4);

and/or the presence of a gas in the gas,

the second anti-freeze valve includes:

and the second relief valve (9) is arranged on the second bypass channel (8) and is suitable for controlling the opening and closing of the second bypass channel (8).

4. The gas water heater of claim 2, wherein the first anti-freeze valve and/or the second anti-freeze valve is a solenoid valve.

5. Gas water heater according to claim 1, characterized in that the first anti-freeze device (14) and/or the second anti-freeze device (15) are provided below the heat exchanger (1).

6. The gas water heater of any one of claims 1-5, further comprising: a control device (10) connected to the heating device (2), the first anti-freeze device (14) and/or the second anti-freeze device (15) and adapted to control the heating device (2), the first anti-freeze device (14) and/or the second anti-freeze device (15) to initiate an anti-freeze mode.

7. The gas water heater of claim 6, further comprising:

temperature-detecting device (11) is located heat exchange tube (13) are close to water inlet department, temperature-detecting device (11) with controlling means (10) are connected, are suitable for when the detected value less than or equal to of temperature-detecting device (11) predetermines the temperature, just during heating device (2) prevent frostbite and become invalid, controlling means (10) control first freeze-proof device (14) with second freeze-proof device (15) are in the mode of preventing frostbite.

8. The gas water heater of claim 7, further comprising:

and the timing device is connected with the control device (10) and is suitable for starting timing when the detection value of the temperature detection device (11) is less than or equal to the preset temperature, the timing time of the timing device lasts for a first preset time, and the detection value of the temperature detection device (11) is still less than or equal to the preset temperature, namely the heating device (2) is subjected to anti-freezing failure.

9. Gas water heater according to claim 7, characterized in that when the temperature detection means (11) detects a value greater than said preset temperature, said control means (10) controls said first anti-freeze device (14) in a water inlet mode, said second anti-freeze device (15) in a water outlet mode, said heating means (2) being switched off.

10. The gas water heater of claim 7, wherein the preset temperature is 5 ℃.

11. The gas water heater of any one of claims 1-5, further comprising:

the check valve (12) is arranged in a smoke pipe of the gas water heater and is suitable for preventing outside air from entering the gas water heater.

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