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, a valve used for adjusting water flow is arranged on the bypass pipe, and the water tank is arranged on the water outlet pipe. The connection point of the bypass pipe and the water outlet pipe is located between the heat exchanger and the water tank. According to the gas water heater, the water tank is arranged between the by-pass pipe and the water outlet of the water outlet pipe, and the valve is arranged on the by-pass pipe, so that the problems of water stop temperature rise and water stop temperature drop generated during secondary use after the gas water heater is temporarily closed 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. According to different heat sources, they are mainly divided into electric water heaters and gas water heaters. Among them, in a gas water heater, high-temperature flue gas generated by gas combustion exchanges heat with water in a heat exchanger to heat the water in the heat exchanger, and then hot water output is realized.

[0003] Existing gas water heaters mainly include an inlet pipe, an outlet pipe, a heat exchanger, and a burner. Among them, the inlet pipe is connected to the water inlet of the heat exchanger, and the outlet pipe is connected to the water outlet of the heat exchanger. Cold water entering from the water inlet flows through the heat exchanger and exchanges heat with the heat exchanger, and 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 above 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 outlet 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 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 this is also a long-standing pain point in the industry. 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 an inlet pipe, an outlet pipe, a bypass pipe, a heat exchanger, and a water tank. One end of the inlet pipe is connected to the inlet of the heat exchanger, one end of the outlet pipe is connected to the outlet of the heat exchanger, both ends of the bypass pipe are respectively connected to the inlet pipe and the outlet pipe, a valve for adjusting the water flow rate is arranged on the bypass pipe, the water tank is arranged on the outlet pipe, and the connection point of the bypass pipe and the outlet pipe is located between the heat exchanger and the water tank.

[0007] The gas water heater described in the present utility model has the following beneficial effects compared with the background technology: By arranging a bypass pipe with a flow regulating valve between the water inlet pipe and the water outlet pipe, and by arranging a water tank downstream of the connection point between the bypass pipe and the water outlet pipe, when the gas water heater is used for the second time after being briefly shut down, the valve is in a relatively large opening degree, so that a part of the water flow in the water inlet pipe is diverted 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 and play a role in initially reducing the temperature rise during shutdown. On the other hand, during the startup phase, since the water temperature in the heat exchanger is higher, during this process, the valve on the bypass pipe will gradually reduce the opening degree, making the water flow rate from the water inlet pipe into the heat exchanger larger, releasing the high-temperature water stored in the heat exchanger, and playing a role in initially reducing the temperature drop during shutdown. Since the water tank is arranged downstream of the connection point between the bypass pipe and the water outlet pipe, the water tank can further buffer the high-temperature water after initially reducing the temperature rise during shutdown to avoid the outlet water temperature being too high, and can also further buffer the water flow after initially reducing the temperature drop during shutdown to avoid the outlet water temperature being too low. Therefore, compared with the existing technical solution of separately arranging a buffer water tank on the water outlet pipe, the solution of the present application, due to the mixing of water through the bypass pipe, initially reduces the temperature rise and temperature drop, and has lower design requirements for the volume and structure of the water tank; compared with the existing technical solution of separately arranging a bypass pipe between the water inlet pipe and the water outlet pipe, which requires complex and precise regulation of the bypass ratio of the bypass pipe to meet the requirement of relatively stable outlet water temperature, the solution of the present application, due to the combined buffer effect of the water tank on this basis, can reduce the control precision requirement of the bypass ratio, which is beneficial to reducing the production cost of the gas water heater.

[0008] In one embodiment, the valve is a on-off valve, and a first branch pipe is further arranged 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 arranged 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, at least two on-off valves are arranged on the bypass pipe, and all the on-off valves are connected in parallel.

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

[0012] In one embodiment, the valve is a three-way water proportioning valve, which 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 0.8L.

[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 arranged on the water inlet pipe, and the outlet water temperature sensor is arranged on the water outlet pipe.

[0015] In one embodiment, the gas water heater further includes a casing, and the water inlet pipe, the water outlet pipe, the bypass pipe, the heat exchanger and the water tank are all installed inside the casing. Description of the Drawings

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

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

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

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

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

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

[0022] Figure 7 is a schematic diagram of the gas water heater provided in Embodiment 7 of the present utility model.

[0023] In the figure:

[0024] 1, water inlet pipe; 2, water 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 proportioning valve; 63, three-way water proportioning valve; 7, flow sensor; 8, inlet water temperature sensor; 9, outlet water temperature sensor; 10, casing. Detailed Embodiments

[0025] The present utility model will be further described in detail below in conjunction with the accompanying 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. In addition, it should be noted that for the convenience of description, only the parts related to the present utility model are shown in the drawings, rather than all the structures.

[0026] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can 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 situations.

[0027] 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 between them. Moreover, the first feature being "above", "above", and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "below", and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is lower than that of the second feature.

[0028] 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. It is 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. Therefore, it should not be understood 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 meaning.

[0029] Embodiment 1

[0030] 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 during the secondary use after the gas water heater is briefly closed by arranging a water tank 5 between the bypass pipe 3 and the water outlet of the water outlet pipe 2, and arranging a valve 6 on the bypass pipe 3.

[0031] 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 the user to 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. A valve 6 for adjusting the water flow rate is provided on the bypass pipe 3. In this embodiment, the valve 6 is a switch valve 61, and the switch 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 switch valve 61. The water tank 5 is arranged on the water outlet pipe 2, and the connection point between the bypass pipe 3 and the water outlet pipe 2 is located between the heat exchanger 4 and the water tank 5. It can also be understood that the water tank 5 is located between the outlet end of the bypass pipe 3 and the water outlet of the water outlet pipe 2. The hot water output from the heat exchanger 4 and the cold water output from the bypass pipe 3 enter the water tank 5 for buffering and mixing, so that the hot water output from the water tank 5 to the water outlet can meet the set temperature range for the user to use.

[0032] 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, and 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 exchanges heat with water to achieve heating of the water.

[0033] It is understandable that when the user closes the water outlet during water use, 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, causing the outlet water temperature to be 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 setting a bypass pipe 3 with a flow regulating valve 6 between the water inlet pipe 1 and the water outlet pipe 2, and by setting a water tank 5 downstream of the connection point between the bypass pipe 3 and the water outlet pipe 2, when the gas water heater is used for the second time after being briefly shut down, 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 2. 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 and play a role in initially reducing the temperature rise during shutdown. On the other hand, during the start-up stage, since the water temperature in the heat exchanger 4 is higher, 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 and releasing the high-temperature water stored in the heat exchanger 4, playing a role in initially reducing the temperature drop during shutdown. Since the water tank 5 is arranged downstream of the connection point between the bypass pipe 3 and the water outlet pipe 2, the water tank 5 can further buffer the high-temperature water after initially reducing the temperature rise during shutdown to avoid the outlet water temperature being too high, and can also further buffer the water flow after initially reducing the temperature drop during shutdown to avoid the outlet water temperature being too low. Therefore, compared with the existing technical solution of separately setting a buffer water tank on the water outlet pipe 2, the solution of the present application, due to the mixing of water through the bypass pipe 3, initially reduces the temperature rise and temperature drop, and has lower design requirements for the volume and structure of the water tank 5; compared with the existing technical solution of separately setting a bypass pipe 3 between the water inlet pipe 1 and the water outlet pipe 2, which requires complex and precise regulation of the bypass ratio of the bypass pipe 3 to meet the requirement of relatively stable outlet water temperature, the solution of the present application, due to the combined post-buffer effect of the water tank 5 on this basis, can reduce the control accuracy requirement of the bypass ratio, which is beneficial to reducing the production cost of the gas water heater.

[0034] Specifically, the volume of the water tank 5 is 0.2L to 0.8L. It can be understood that the water tank 5 should have a sufficient volume to hold a sufficient amount of hot water and cold water. On the one hand, it can extend the residence time of 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 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, 0.3L, 0.4L, 0.5L, 0.6L, 0.7L, and 0.8L. 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 0.8L 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 at the first startup and too long a 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 inlet pipe 1 close to the water inlet, and it is used to detect the temperature of the cold water entering the inlet pipe 1. The outlet water temperature sensor 9 is arranged at one end of the outlet pipe 2 close to the water outlet, and it is used to detect the temperature of the hot water discharged from the outlet pipe 2. The outlet water temperature sensor 9 is located downstream of the water tank 5. In practical applications, according to specific temperature detection needs, only the inlet water temperature sensor 8 can be installed on the inlet pipe 1, or only the outlet water temperature sensor 9 can be installed on the outlet pipe 2, or both the inlet water temperature sensor 8 can be installed on the inlet pipe 1 and the outlet water temperature sensor 9 can be installed on the outlet pipe 2.

[0036] Specifically, the gas water heater further includes a flow sensor 7. The flow sensor 7 is arranged on the inlet pipe 1, and along the water flow direction, the flow sensor 7 is located upstream of the bypass pipe 3. In this embodiment, by setting the flow sensor 7, the cold water flow rate in the inlet pipe 1 can be 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.

[0037] Embodiment 2

[0038] As Figure 2As shown in the figure, this embodiment provides a gas water heater, whose structure is similar to that of the first embodiment, 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 switch 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 switch valve 61, and the other end is located downstream of the switch 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 another part can flow through the switch valve 61. By opening or closing the switch valve 61, the cold water flow rate input from the bypass pipe 3 into the outlet pipe 2 can be controlled. For example, if the cold water flow rate input from the 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 switch valve 61 is Q2, then Q = Q1 + Q2. When the switch valve 61 is closed, the cold water flow rate input from the bypass pipe 3 into the outlet pipe 2 is Q1; when the switch valve 61 is opened, the cold water flow rate input from the bypass pipe 3 into the outlet pipe 2 is Q. In this embodiment, by providing the first branch pipe 31 and the switch 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.

[0039] Embodiment III

[0040] As Figure 3As shown in the figure, this embodiment provides a gas water heater, whose structure is similar to that of the first embodiment, except that: a second branch pipe 32 is further provided on the bypass pipe 3, two on-off valves 61 are connected in series on the bypass pipe 3, and the second branch pipe 32 is connected in parallel with one of the on-off valves 61. Specifically, the two on-off valves 61 are connected in series so that the cold water in the bypass pipe 3 can flow through the two on-off valves 61 in sequence. Along the water flow direction, the second branch pipe 32 is connected in parallel with the upstream on-off valve 61 or the downstream on-off valve 61. When the second branch pipe 32 is connected in parallel with the downstream on-off valve 61, both ends of the second branch pipe 32 are connected to the bypass pipe 3, and the downstream on-off valve 61 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 on-off valves 61 are also Q. The flow rate of the second branch pipe 32 is Q3. When the upstream on-off valve 61 is closed, the cold water flow rate input from the bypass pipe 3 to the water outlet pipe 2 is 0; when the upstream on-off valve 61 and the downstream on-off valve 61 are opened, the cold water flow rate input from the bypass pipe 3 to the water outlet pipe 2 is Q; when the upstream on-off valve 61 is opened and the downstream on-off valve 61 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 to be connected in parallel with the downstream on-off valve 61, the flow rate of the bypass pipe 3 can be adjusted in three gears, that is, one gear has a flow rate of 0, another gear has a flow rate of Q, and the other gear has a flow rate of Q3. Similarly, when the second branch pipe 32 is connected in parallel with the upstream on-off valve 61, the flow rate of the bypass pipe 3 can be adjusted in three gears, that is, one gear has a flow rate of 0, another gear has a flow rate of Q, and the other gear has a flow rate of Q3.

[0041] Embodiment Four

[0042] As Figure 4As shown in the figure, this embodiment provides a gas water heater, whose structure is similar to that of Embodiment 1, with the difference being 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.

[0043] Embodiment Five

[0044] As Figure 5 shown in the figure, this embodiment provides a gas water heater, whose structure is similar to that of Embodiment 1, with the difference being 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.

[0045] Embodiment Six

[0046] As Figure 6 shown in the figure, this embodiment provides a gas water heater, whose structure is similar to that of Embodiment 1, with the difference being 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, and making the bypass ratio adjustment range of the bypass pipe 3 larger.

[0047] Embodiment Seven

[0048] As Figure 7As shown in the figure, this embodiment provides a gas water heater, whose structure is similar to that of Embodiment 1, with the difference being that: there are two water tanks 5 provided on the water outlet pipe 2, one of the water tanks 5 is located between the heat exchanger 4 and the bypass pipe 3, and the other water tank 5 is located between the heat exchanger 4 and the water outlet of the water outlet pipe 2. By providing a water tank 5 upstream of the bypass pipe 3, the hot water output from the heat exchanger 4 can be buffered and mixed in the water tank 5 before being mixed with the cold water. So that the temperature of the hot water entering the downstream water tank 5 is relatively constant, and after the hot water is mixed with the cold water in the water tank 5, it is more conducive to reducing the temperature change of the hot water discharged from the water outlet.

[0049] 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 connection point between the bypass pipe (3) and the water outlet pipe (2) is located between the heat exchanger (4) and the water tank (5); 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-0.8L.

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 casing (10), wherein the water inlet pipe (1), the water outlet pipe (2), the bypass pipe (3), the heat exchanger (4) and the water tank (5) are all installed in the casing (10).

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