Gas water heater

Abstract

The utility model belongs to the technical field of electric appliances, and discloses a gas water heater. One end of the water inlet pipe is connected with an inlet of the heat exchanger, one end of the water outlet pipe is connected with an outlet of the heat exchanger, the two ends of the bypass pipe are connected with the water inlet pipe and the water outlet pipe respectively, and the water tank is arranged on the water outlet pipe and located between the heat exchanger and the bypass pipe. According to the gas water heater, the water tank is arranged between the heat exchanger and the bypass pipe, and the valve is arranged on the bypass pipe, so that the problems of water stop temperature rise and water stop temperature drop generated when the gas water heater is used for the second time after being closed for a short time are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of electrical appliances, in particular to a gas water heater. Background Art

[0002] Water heaters are commonly used household appliances in people's daily lives. They are mainly divided into electric water heaters and gas water heaters according to different heat sources. Among them, a gas water heater realizes heat exchange between the high-temperature flue gas generated by gas combustion and the water in the heat exchanger, so as to heat the water in the heat exchanger and then realize the output of hot water.

[0003] The existing gas water heaters mainly include a water inlet pipe, a water outlet pipe, a heat exchanger and a burner. Among them, the water inlet pipe is connected to the water inlet of the heat exchanger, and the water outlet pipe is connected to the water outlet of the heat exchanger. The cold water entering from the water inlet flows through the heat exchanger and exchanges heat with the heat exchanger. The heated hot water is discharged from the water outlet for users to use. The burner is used to heat the heat exchanger to provide heat energy. However, in some usage scenarios, users will close the water usage point and then use the water again after a short wait. In this scenario, when the water heater shuts off, the water in the heat exchanger is in a static state, so it is continuously heated by the residual heat of the heat exchanger, resulting in an increase in water temperature and exceeding the set temperature. When using the water again, the high-temperature water heated by the residual heat of the heat exchanger will flow out along the water pipe, making the outlet water temperature significantly higher than the set temperature. This phenomenon is called the stop water temperature rise. Then, the cold water newly flowing in from the water inlet pipe flows out without being heated by the heat exchanger, making the outlet water temperature significantly lower than the set temperature. This phenomenon is called the stop water temperature drop. It can be seen that in the secondary usage scenario of the water heater, there is a water temperature fluctuation process of first rising and then falling in the outlet water temperature, which greatly affects the user experience and is also a pain point in the industry for a long time. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a gas water heater, which can effectively reduce the stop water temperature rise and stop water temperature drop generated when the gas water heater is used for the second time after a short shutdown.

[0005] The above technical problems are solved by the following technical solutions:

[0006] A gas water heater includes a water inlet pipe, a water outlet pipe, a bypass pipe, a heat exchanger and a water tank. One end of the water inlet pipe is connected to the inlet of the heat exchanger, one end of the water outlet pipe is connected to the outlet of the heat exchanger, both ends of the bypass pipe are respectively connected to the water inlet pipe and the water outlet pipe, a valve for adjusting the water flow is arranged on the bypass pipe, the water tank is arranged on the water outlet pipe, and the water tank is located between the heat exchanger and the bypass pipe.

[0007] The gas water heater described in the present utility model has the following beneficial effects compared with the background technology: By providing a bypass pipe with a flow regulating valve between the water inlet pipe and the water outlet pipe, and by providing a water tank between the outlet of the heat exchanger and the bypass pipe, when the gas water heater is used for the second time after being briefly turned off, the valve is in a relatively large opening, so that a part of the water flow in the water inlet pipe is diverted to flow from the bypass pipe to the water outlet pipe. At the same time, another part of the water flow flows from the water inlet pipe into the heat exchanger. The water flow flowing from the water inlet pipe into the heat exchanger has a reduced flow rate due to diversion. To ensure that the outlet water temperature remains unchanged, the water flow in the heat exchanger will be heated to a higher temperature. On the one hand, the temperature of the heat exchanger is higher, and the temperature difference with the surrounding environment is larger, which can accelerate heat dissipation. Coupled with the buffering effect of the water tank on the high-temperature water, the stop water temperature rise can be effectively reduced. On the other hand, during the startup stage, since the water temperature in the heat exchanger is higher, compared with the prior art without a bypass pipe, more heat energy can be stored. Since the water tank is provided downstream of the outlet of the heat exchanger and between the outlet of the heat exchanger and the bypass pipe, the water tank is equivalent to an energy storage expansion unit of the heat exchanger, enabling the heat exchanger and the water tank to store more high-temperature water. During this process, the valve on the bypass pipe will gradually reduce the opening, increasing the water flow rate from the water inlet pipe to the heat exchanger, releasing the high-temperature water stored in the heat exchanger and the water tank, thereby effectively reducing the stop water temperature drop during the second use until the gas water heater burns and operates normally. Through the above implementation, due to the extended energy storage effect of the water tank, the requirements for the heat exchange pipes and volume in the heat exchanger can be reduced, enabling the heat exchanger to be designed more compact and small. Compared with the conventional buffer water tank scheme, the volume of the water tank can also be designed smaller to meet the above technical principles.

[0008] In one embodiment, the valve is a on-off valve, and a first branch pipe is further provided on the bypass pipe, and the first branch pipe is connected in parallel with the on-off valve.

[0009] In one embodiment, the valve is a on-off valve, and a second branch pipe is further provided on the bypass pipe. Two on-off valves are arranged in series on the bypass pipe, and the second branch pipe is connected in parallel with one of the on-off valves.

[0010] In one embodiment, the valve is a on-off valve, and at least two on-off valves are provided on the bypass pipe, and all the on-off valves are connected in parallel.

[0011] In one embodiment, the valve is a water ratio valve with adjustable opening.

[0012] In one embodiment, the valve is a three-way water ratio valve. The three-way water ratio valve has an inlet end and two outlet ends. The inlet end and one of the outlet ends are connected to the water inlet pipe, and the other outlet end is connected to the bypass pipe.

[0013] In one embodiment, the volume of the water tank is 0.2L to 0.5L.

[0014] In one embodiment, the gas water heater further includes an inlet water temperature sensor and / or an outlet water temperature sensor. The inlet water temperature sensor is disposed on the inlet pipe, and the outlet water temperature sensor is disposed on the outlet pipe.

[0015] In one embodiment, the gas water heater further includes a water tank temperature sensor. Along the water flow direction, the water tank temperature sensor is disposed upstream and / or downstream of the water tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the gas water heater provided by Embodiment 1 of the present utility model;

[0017] Figure 2 is a schematic diagram of the gas water heater provided by Embodiment 2 of the present utility model;

[0018] Figure 3 is a schematic diagram of the gas water heater provided by Embodiment 3 of the present utility model;

[0019] Figure 4 is a schematic diagram of the gas water heater provided by Embodiment 4 of the present utility model;

[0020] Figure 5 is a schematic diagram of the gas water heater provided by Embodiment 5 of the present utility model;

[0021] Figure 6 is a schematic diagram of the gas water heater provided by Embodiment 6 of the present utility model.

[0022] In the figure:

[0023] 1. Inlet pipe; 2. Outlet pipe; 3. Bypass pipe; 31. First branch pipe; 32. Second branch pipe; 33. Third branch pipe; 4. Heat exchanger; 5. Water tank; 6. Valve; 61. On-off valve; 62. Water ratio valve; 63. Three-way water ratio valve; 7. Flow sensor; 8. Inlet water temperature sensor; 9. Outlet water temperature sensor; 10. Machine shell; 11. Water tank temperature sensor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The present utility model will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present utility model, rather than limiting the present utility model. Additionally, it should be noted that for the sake of description, only the parts related to the present utility model rather than all the structures are shown in the drawings.

[0025] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0026] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0027] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying 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 a limitation to the present utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meanings.

[0028] Embodiment 1

[0029] As Figure 1 shown, this embodiment provides a gas water heater, which can solve the problems of stop water temperature rise and stop water temperature drop when the gas water heater is used for the second time after being briefly turned off by arranging a water tank 5 between the heat exchanger 4 and the bypass pipe 3, and by arranging a valve 6 on the bypass pipe 3.

[0030] Specifically, the gas water heater provided in this embodiment includes a water inlet pipe 1, a water outlet pipe 2, a bypass pipe 3, a heat exchanger 4, and a water tank 5. Among them, the water inlet pipe 1 and the water outlet pipe 2 are used for conveying water. The water inlet pipe 1 is used for conveying cold water before heating, and the water outlet pipe 2 is used for conveying hot water after heating. The heat exchanger 4 is used for heating water. The heat exchanger 4 has an inlet for water to enter its interior and an outlet for water to discharge. One end of the water inlet pipe 1 is connected to the inlet of the heat exchanger 4, and the other end forms a water inlet. The water inlet of the water inlet pipe 1 is used to connect to a water source so that cold water can be input into the heat exchanger 4 through the water inlet pipe 1. One end of the water outlet pipe 2 is connected to the outlet of the heat exchanger 4, and the other end forms a water outlet. The water outlet of the water outlet pipe 2 is used to connect to a flushing device (such as a shower head) so that the hot water heated in the heat exchanger 4 can be output through the water outlet pipe 2 to the flushing device for user use. Both ends of the bypass pipe 3 are respectively connected to the water inlet pipe 1 and the water outlet pipe 2, so that a part of the cold water in the water inlet pipe 1 can be directly input into the water outlet pipe 2 through the bypass pipe 3. The cold water in the bypass pipe 3 is mixed with the hot water in the water outlet pipe 2 so that the temperature of the hot water discharged from the water outlet reaches the set temperature when the user uses it. A valve 6 for adjusting the water flow rate is provided on the bypass pipe 3. The water tank 5 is a tank with a certain volume, which is used to store the hot water flowing out of the heat exchanger 4. The water tank 5 is arranged on the water outlet pipe 2, and the water tank 5 is located between the heat exchanger 4 and the bypass pipe 3. The hot water output from the heat exchanger 4 first enters the water tank 5. The hot water buffers and stays in the water tank 5, and then the hot water output from the water tank 5 is mixed with the cold water in the bypass pipe 3, and finally is output through the water outlet for use.

[0031] Specifically, the gas water heater further includes a casing 10 and a burner. The casing 10 is the outer shell of the entire gas water heater. The water inlet pipe 1, the water outlet pipe 2, the bypass pipe 3, the heat exchanger 4, the water tank 5, and the burner are all installed inside the casing 10. The burner is used for burning gas and generating high-temperature flue gas to heat the heat exchanger 4. The heat exchanger 4 includes a copper pipe arranged in a bent shape and fins arranged on the outer wall of the copper pipe. The heated heat exchanger 4 exchanges heat with water to achieve heating of the water.

[0032] It can be understood that when the user closes the water outlet during the water use process, the water in the gas water heater stops flowing. Although the burner is closed accordingly at this time, the residual heat on the heat exchanger 4 will still continuously heat the water inside. When the user reopens the water outlet, the high-temperature water heated by the residual heat of the heat exchanger 4 will flow out along the water outlet pipe 2, making the outlet water temperature significantly higher than the set temperature. Also, when the user reopens the water outlet, the cold water in the water inlet pipe 1 flows into the heat exchanger 4. Since the burner reignites and burns after obtaining the flow signal of the water inlet pipe 1, affected by factors such as the start-up delay of the burner and the duration of reheating the heat exchanger 4 by the high-temperature flue gas, this part of the cold water cannot absorb heat sufficiently in the heat exchanger 4, resulting in the outlet water temperature being significantly lower than the set temperature. By arranging a bypass pipe 3 with a flow regulating valve 6 between the water inlet pipe 1 and the water outlet pipe 2, and by arranging a water tank 5 between the outlet of the heat exchanger 4 and the bypass pipe 3, when the gas water heater is used for the second time after a short-term shutdown, the valve 6 is in a relatively large opening degree, so that a part of the water flow in the water inlet pipe 1 is diverted to flow from the bypass pipe 3 to the water outlet pipe. At the same time, another part of the water flow flows from the water inlet pipe 1 into the heat exchanger 4. The water flow flowing from the water inlet pipe 1 to the heat exchanger 4 has a reduced flow rate due to diversion. To ensure that the outlet water temperature remains unchanged, the water flow in the heat exchanger 4 will be heated to a higher temperature. On the one hand, the temperature of the heat exchanger 4 is higher, and the temperature difference with the surrounding environment is larger, which can accelerate heat dissipation. Coupled with the buffering effect of the water tank 5 on the high-temperature water, the stop water temperature rise can be effectively reduced. On the other hand, during the start-up stage, since the water temperature in the heat exchanger 4 is higher, compared with the existing solution without the bypass pipe 3, more heat energy can be stored. Since the water tank 5 is arranged downstream of the outlet of the heat exchanger 4 and between the outlet of the heat exchanger 4 and the bypass pipe 3, the water tank 5 is equivalent to an energy storage expansion unit of the heat exchanger 4, enabling the heat exchanger 4 and the water tank 5 to store more high-temperature water. During this process, the valve 6 on the bypass pipe 3 will gradually reduce the opening degree, increasing the water flow rate from the water inlet pipe 1 to the heat exchanger 4, releasing the high-temperature water stored in the heat exchanger 4 and the water tank 5, thereby effectively reducing the stop water temperature drop during the second use until the gas water heater operates normally in combustion. Through the above implementation, due to the extended energy storage effect of the water tank 5, the requirements for the heat exchange pipes and volume inside the heat exchanger 4 can be reduced, so that the heat exchanger 4 can be designed to be more compact and small. Compared with the conventional buffer water tank solution, the volume of the water tank 5 can also be designed to be smaller to meet the above technical principle.

[0033] In this embodiment, the valve 6 is a switching valve 61, and the switching valve 61 is used to control the opening and closing of the bypass pipe 3. In practical applications, the bypass ratio of the bypass pipe 3 can be adjusted by opening or closing the switching valve 61. After the cold water enters the water inlet pipe 1 from the water inlet, a part of the cold water enters the heat exchanger 4 for heating, and the other part of the cold water directly mixes with the hot water discharged from the water tank 5 through the bypass pipe 3. Since the bypass pipe 3 distributes a part of the flow rate, the flow rate of the cold water entering the heat exchanger 4 is reduced, which is more conducive to heating the cold water and enabling the hot water in the heat exchanger 4 to be heated to a higher temperature.

[0034] Specifically, the volume of the water tank 5 is 0.2L to 0.5L. It can be understood that the water tank 5 should have a sufficient volume to accommodate a sufficient amount of hot water. On the one hand, it can extend the residence time of the water in the water tank 5 to promote heat exchange. On the other hand, it can make the incoming high-temperature hot water have a higher heat quantity to achieve the energy storage function of the water tank 5. In this embodiment, the selection of the volume of the water tank 5 includes but is not limited to 0.2L, 0.25L, 0.3L, 0.35L, 0.4L, 0.45L, 0.5L. In practical applications, the volume of the water tank 5 should not be less than 0.2L to avoid affecting the energy storage effect due to too small a volume. Also, the volume of the water tank 5 should not be greater than 0.5L to avoid affecting the overall layout of the gas water heater due to too large a volume of the water tank 5, and to avoid too much cold water inside the gas water heater during the first startup and too long waiting time for the user.

[0035] Specifically, the gas water heater further includes an inlet water temperature sensor 8 and / or an outlet water temperature sensor 9. The inlet water temperature sensor 8 is arranged at one end of the water inlet pipe 1 close to the water inlet, and it is used to detect the temperature of the cold water entering the water inlet pipe 1. The outlet water temperature sensor 9 is arranged at one end of the water outlet pipe 2 close to the water outlet, and it is used to detect the temperature of the hot water discharged from the water outlet pipe 2. In practical applications, according to the specific temperature detection requirements, only the inlet water temperature sensor 8 can be installed on the water inlet pipe 1, or only the outlet water temperature sensor 9 can be installed on the water outlet pipe 2, or both the inlet water temperature sensor 8 can be installed on the water inlet pipe 1 and the outlet water temperature sensor 9 can be installed on the water outlet pipe 2.

[0036] Specifically, the gas water heater further includes a water tank temperature sensor 11. Along the direction of the water flow, the water tank temperature sensor 11 is disposed upstream and / or downstream of the water tank 5. It can be understood that when the water tank temperature sensor 11 is disposed upstream of the water tank 5, it can more accurately detect the temperature of the hot water entering the water tank 5. At the same time, the temperature value detected by the water tank temperature sensor 11 corresponds to the temperature of the hot water discharged from the outlet of the heat exchanger 4. In practical applications, the firepower of the burner can be adjusted according to the detection data of the water tank temperature sensor 11. When the water tank temperature sensor 11 is disposed downstream of the water tank 5, it can more accurately detect the temperature of the hot water discharged from the water tank 5. In practical applications, the flow rate of the bypass pipe 3 can be adjusted according to the detection data of the water tank temperature sensor 11 to ensure that the actual temperature of the hot water discharged from the water outlet matches the set temperature.

[0037] Specifically, the gas water heater further includes a flow sensor 7. The flow sensor 7 is disposed on the water inlet pipe 1. Along the water flow direction, the flow sensor 7 is located upstream of the bypass pipe 3. In this embodiment, by providing the flow sensor 7, the cold water flow rate in the water inlet pipe 1 is detected. When the cold water flow rate reaches the set threshold value, the burner can be turned on, and the gas water heater starts to output hot water for the user to use.

[0038] Embodiment II

[0039] As Figure 2 shown, this embodiment provides a gas water heater, whose structure is similar to that of Embodiment I, except that: a first branch pipe 31 is further provided on the bypass pipe 3, and the first branch pipe 31 is connected in parallel with the switching valve 61. Specifically, both ends of the first branch pipe 31 are connected to the bypass pipe 3. Along the water flow direction, one end of the first branch pipe 31 is located upstream of the switching valve 61, and the other end is located downstream of the switching valve 61. By providing the first branch pipe 31, a part of the cold water in the bypass pipe 3 can flow through the first branch pipe 31, and the other part can flow through the switching valve 61. By opening or closing the switching valve 61, the cold water flow rate input from the bypass pipe 3 into the water outlet pipe 2 can be controlled. For example, the cold water flow rate input from the water inlet pipe 1 into the bypass pipe 3 is Q, the flow rate of the first branch pipe 31 is Q1, and the flow rate of the switching valve 61 is Q2, then Q = Q1 + Q2. When the switching valve 61 is closed, the cold water flow rate input from the bypass pipe 3 into the water outlet pipe 2 is Q1; when the switching valve 61 is opened, the cold water flow rate input from the bypass pipe 3 into the water outlet pipe 2 is Q. In this embodiment, by providing the first branch pipe 31 and the switching valve 61 in parallel, the flow rate of the bypass pipe 3 can be adjusted in two gears, that is, one gear has a flow rate of Q1, and the other gear has a flow rate of Q.

[0040] Embodiment III

[0041] As Figure 3As shown in the figure, this embodiment provides a gas water heater, whose structure is similar to that of the first embodiment, with the difference being that: a second branch pipe 32 is further provided on the bypass pipe 3, and two switching valves 61 are connected in series on the bypass pipe 2, and the second branch pipe 32 is connected in parallel with one of the switching valves 61. Specifically, the two switching valves 61 are connected in series so that the cold water in the bypass pipe 2 can flow through the two switching valves 61 in sequence. Along the water flow direction, the second branch pipe 32 is connected in parallel with the switching valve 61 located upstream, or with the switching valve 61 located downstream. When the second branch pipe 32 is connected in parallel with the switching valve 61 located downstream, both ends of the second branch pipe 32 are connected to the bypass pipe 3, and the switching valve 61 located downstream is located between the two connection points of the second branch pipe 32 and the bypass pipe 3. For example, the cold water flow rate input from the water inlet pipe 1 to the bypass pipe 3 is Q, and the flow rates corresponding to the two switching valves 61 are also Q. The flow rate of the second branch pipe 32 is Q3. When the switching valve 61 located upstream is closed, the cold water flow rate input from the bypass pipe 3 to the water outlet pipe 2 is 0; when the switching valve 61 located upstream and the switching valve 61 located downstream are opened, the cold water flow rate input from the bypass pipe 3 to the water outlet pipe 2 is Q; when the switching valve 61 located upstream is opened and the switching valve 61 located downstream is closed, the cold water flow rate input from the bypass pipe 3 to the water outlet pipe 2 is Q3. In this embodiment, by setting the second branch pipe 32 to be connected in parallel with the switching valve 61 located downstream, the flow rate of the bypass pipe 3 can be adjusted in three levels, that is, one level of the flow rate is 0, another level of the flow rate is Q, and another level of the flow rate is Q3. Similarly, when the second branch pipe 32 is connected in parallel with the switching valve 61 located upstream, the flow rate of the bypass pipe 3 can be adjusted in three levels, that is, one level of the flow rate is 0, another level of the flow rate is Q, and another level of the flow rate is Q3.

[0042] Embodiment Four

[0043] As Figure 4As shown in the figure, this embodiment provides a gas water heater, whose structure is similar to that of the first embodiment, except that: at least two switching valves 61 are provided on the bypass pipe 3, and all the switching valves 61 are connected in parallel. In this embodiment, two switching valves 61 are provided on the bypass pipe 3, and the two switching valves 61 are connected in parallel to the bypass pipe 3 through a third branch pipe 33. For example, the cold water flow rate input from the water inlet pipe 1 to the bypass pipe 3 is Q, and the flow rate of each branch corresponding to the switching valve 61 is Q4. When one of the switching valves 61 is opened, the cold water flow rate input from the bypass pipe 3 to the water outlet pipe 2 is Q4; when two switching valves 61 are opened, the cold water flow rate input from the bypass pipe 3 to the water outlet pipe 2 is Q; when all the switching valves 61 are closed, the cold water flow rate input from the bypass pipe 3 to the water outlet pipe 2 is 0. In this embodiment, by providing two switching valves 61 in parallel, the bypass pipe 3 can be adjusted in three gears, that is, the flow rate of one gear is 0, the flow rate of another gear is Q, and the flow rate of another gear is Q4. Similarly, when the number of switching valves 61 is set to other numbers, such as 3, 4, or 5, the bypass pipe 3 can be adjusted in more gears. In another embodiment, the flow rates of the switching valves 61 are different, so that the bypass pipe 3 can have more gear adjustments. For example, when the number of switching valves 61 is two and the flow rates of the two switching valves 61 are different, the bypass pipe 3 can be adjusted in four gears.

[0044] Embodiment Five

[0045] As Figure 5 shown in the figure, this embodiment provides a gas water heater, whose structure is similar to that of the first embodiment, except that: the valve 6 is a water ratio valve 62 with adjustable opening. By adjusting the opening of the water ratio valve 62, the flow rate of the bypass pipe 3 can be adjusted steplessly, that is, the bypass ratio adjustment range of the bypass pipe 3 is larger.

[0046] Embodiment Six

[0047] As Figure 6 shown in the figure, this embodiment provides a gas water heater, whose structure is similar to that of the first embodiment, except that: the valve 6 is a three-way water ratio valve 63, and the three-way water ratio valve 63 has one inlet end and two outlet ends. The inlet end of the three-way water ratio valve 63 is connected upstream of the water inlet pipe 1, one of the outlet ends of the three-way water ratio valve 63 is connected downstream of the water inlet pipe 1, and the other outlet end of the three-way water ratio valve 63 is connected to one end of the bypass pipe 3. It can also be understood that a three-way water ratio valve 63 is provided at the connection between the bypass pipe 3 and the water inlet pipe 1. The three-way water ratio valve 63 can adjust the flow rate ratio of the two outlet ends, thereby realizing stepless adjustment of the flow rate of the bypass pipe 3, so that the bypass ratio adjustment range of the bypass pipe 3 is larger.

[0048] Obviously, the above embodiments of the present utility model are merely examples for clearly illustrating the present utility model, rather than limitations on the implementation manners of the present utility model. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present utility model. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present utility model shall be included within the protection scope of the claims of the present utility model.

Claims

1. A gas water heater, characterized in that: The invention comprises a water inlet pipe (1), a water outlet pipe (2), a bypass pipe (3), a heat exchanger (4) and a water tank (5), wherein one end of the water inlet pipe (1) is connected to the inlet of the heat exchanger (4), one end of the water outlet pipe (2) is connected to the outlet of the heat exchanger (4), two ends of the bypass pipe (3) are respectively connected to the water inlet pipe (1) and the water outlet pipe (2), a valve (6) for adjusting the water flow is provided on the bypass pipe (3), the water tank (5) is provided on the water outlet pipe (2), and the water tank (5) is located between the heat exchanger (4) and the bypass pipe (3); The valve (6) is an on-off valve (61), the bypass pipe (3) is further provided with a second branch pipe (32), two on-off valves (61) are provided in series on the bypass pipe (3), and the second branch pipe (32) is connected in parallel to one of the on-off valves (61); Alternatively, the valve (6) is an on-off valve (61), at least two of the on-off valves (61) are provided on the bypass pipe (3), and all of the on-off valves (61) are connected in parallel.

2. The gas water heater according to claim 1, characterized in that: The volume of the water tank (5) is 0.2L-0.5L.

3. The gas water heater according to claim 1, characterized in that: The gas water heater further comprises a water inlet temperature sensor (8) and / or a water outlet temperature sensor (9), wherein the water inlet temperature sensor (8) is arranged on the water inlet pipe (1), and the water outlet temperature sensor (9) is arranged on the water outlet pipe (2).

4. The gas water heater according to claim 1, characterized in that: The gas water heater further comprises a water tank temperature sensor (11), and the water tank temperature sensor (11) is arranged upstream and / or downstream of the water tank (5) along the water flow direction.

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