A gas water heater

Abstract

The utility model belongs to water heater technical field discloses a kind of gas water heater. Gas water heater includes combustor, heat exchange subassembly, waterway subassembly and water pump, heat exchange subassembly includes series connection primary heat exchanger and secondary heat exchanger, primary heat exchanger is used to absorb the heat generated by gas combustion in combustor, secondary heat exchanger includes heat exchange pipe, and heat exchange pipe is used to absorb flue gas heat;Waterway subassembly includes inlet pipe, outlet pipe and bypass pipe, inlet pipe is communicated with secondary heat exchanger, outlet pipe is communicated with primary heat exchanger, bypass pipe can communicate outlet pipe and inlet pipe, to form internal circulation flow channel;Water pump is set on the internal circulation flow channel, and water pump is used to drive fluid flow. The gas water heater can reach the first energy efficiency, and realize internal circulation by setting bypass pipe, and replace the water tank in the prior art by using secondary heat exchanger, which is beneficial to simplify the result, reduce cost and solve the problem of cold water. Secondary heat exchanger includes heat exchange pipe, and the occupied space is small.

Description

Technical Field

[0001] This utility model relates to the field of water heater technology, and in particular to a gas water heater. Background Technology

[0002] With the improvement of living standards, users have higher requirements for water comfort. Gas water heaters, with their rapid heating and no need for preheating, have seen rapid development. However, during use, gas water heaters sometimes shut off. When the water is turned off, the residual heat of the burner and the flue gas continue to heat the hot water in the pipes, causing the temperature to rise and forming hot water. When the water heater is restarted, the hot water caused by the temperature rise after the water was turned off, combined with the cold water that enters during the start-up process, creates an uncomfortable experience for users, commonly known as the "scalding water" problem.

[0003] To solve the problem of "cold water scalding," existing gas water heaters require the addition of a circulation pipe and a separate water tank on the inlet pipe to store cold water. When the water supply is turned off, the cold water in the tank is mixed with the partially heated water from the off-line system via internal circulation to resolve the issue. However, this design requires a separate water tank, increasing costs and the overall size of the gas water heater, thus affecting product competitiveness. Furthermore, the utilization rate of heat generated by gas combustion within the gas water heater is low. Utility Model Content

[0004] The purpose of this utility model is to provide a gas water heater that can solve the problem of "cold water scalding", reduce product size, and improve heat utilization.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A gas water heater, comprising:

[0007] Burner;

[0008] A heat exchange assembly includes a primary heat exchanger and a secondary heat exchanger connected in series. The primary heat exchanger is used to absorb the heat generated by the combustion of gas in the burner, and the secondary heat exchanger includes heat exchange tubes for absorbing heat from the flue gas.

[0009] The water circuit assembly includes an inlet pipe, an outlet pipe, and a bypass pipe. The inlet pipe is connected to the secondary heat exchanger, the outlet pipe is connected to the primary heat exchanger, and the bypass pipe can connect the outlet pipe and the inlet pipe to form an internal circulation channel.

[0010] A water pump is installed on the inner circulation channel, and the water pump is used to drive the fluid flow.

[0011] As an alternative to the aforementioned gas water heater, at least a portion of the heat exchange tubes are disposed above the primary heat exchanger.

[0012] As an optional solution for the above-mentioned gas water heater, the heat exchange tube bending plate is located on the top surface of the first-stage heat exchanger;

[0013] Alternatively, the heat exchange tubes may be wound around the primary heat exchanger circumferentially.

[0014] As an alternative to the aforementioned gas water heater, the water pump is installed on the water inlet pipe.

[0015] As an alternative to the aforementioned gas water heater, the water pump is located at one end of the inlet pipe that connects to the bypass pipe.

[0016] As an alternative to the aforementioned gas water heater, a switching valve is provided on the bypass pipe, and the volume of the bypass pipe located between the switching valve and the inlet pipe is smaller than the volume of the bypass pipe located between the switching valve and the outlet pipe.

[0017] As an alternative to the above-mentioned gas water heater, the length of the bypass pipe located between the switch valve and the inlet pipe is less than the length of the bypass pipe located between the switch valve and the outlet pipe;

[0018] And / or, the flow area of ​​the bypass pipe located between the switching valve and the inlet pipe is smaller than the flow area of ​​the bypass pipe located between the switching valve and the outlet pipe.

[0019] As an alternative solution for the aforementioned gas water heater, a one-way valve is provided on the bypass pipe. The one-way valve can prevent the fluid in the bypass pipe from flowing from the inlet pipe to the outlet pipe. The one-way valve is located between the switch valve and the inlet pipe.

[0020] As an alternative to the aforementioned gas water heater, the gas water heater further includes a return pipe connected to the internal circulation channel. The return pipe is used to connect to an external water supply line, and the water pump is located downstream of the return pipe to drive the return water flow.

[0021] As an optional solution for the above-mentioned gas water heater, an intermediate temperature detection element is provided between the outlet of the secondary heat exchanger and the inlet of the primary heat exchanger, and the intermediate temperature detection element is communicatively connected to the burner.

[0022] The beneficial effects of this utility model are:

[0023] In the gas water heater provided by this utility model, an internal circulation channel is formed by setting a bypass pipe. On the one hand, when the gas water heater is turned off, the water in the internal circulation channel is driven to circulate, so that the residual heat of the burner can evenly heat the water in the internal circulation channel, avoiding abnormal local water temperature rise and the formation of overly hot water, thus solving the problem of excessively high outlet water temperature when the gas water heater is restarted. On the other hand, the water circulation in the internal circulation channel can heat the cold water in the internal circulation channel, such as some of the cold water located in the inlet pipe, avoiding the problem of cold water coming out when the gas water heater is restarted, and providing sufficient heating time for the cold water newly entering the inlet pipe, ensuring that the gas water heater can be used immediately and achieving zero cold water.

[0024] The secondary heat exchanger includes heat exchange tubes, which can absorb heat from flue gas while reducing the space occupied, thus reducing the overall size of the unit, lowering costs, and improving product utilization. The heat exchange tubes can fully contact the flue gas for heat exchange, improving heat utilization and avoiding heat waste.

[0025] The water pump, installed on the inlet pipe, not only powers the flow of water within the internal circulation channel for rapid and even mixing of hot and cold water, but also powers the flow of cold water entering the inlet pipe when the gas water heater is running, preventing insufficient water pressure from affecting the water intake. By placing the water pump on the inlet pipe, it can provide power both during water intake and when the gas water heater is turned off, eliminating the need for an additional pump, thus reducing the number of parts and lowering costs.

[0026] In addition, by setting up a secondary heat exchanger, not only can the heat of the flue gas be utilized to improve the heat utilization rate, but the secondary heat exchanger can also play the role of a water tank in the existing technology. That is, the secondary heat exchanger can store a certain amount of water, increasing the total amount of hot water after mixing. This allows the user to be provided with a certain amount of uniformly heated mixed water when the gas water heater is turned on again, thus providing sufficient heating time for the cold water entering the inlet pipe and achieving a continuous and uninterrupted supply of hot water. Attached Figure Description

[0027] Figure 1 This is a structural schematic diagram of the gas water heater provided by this utility model.

[0028] In the picture:

[0029] 10. Casing; 20. Heat exchange assembly; 21. Primary heat exchanger; 22. Secondary heat exchanger; 31. Inlet pipe; 32. Outlet pipe; 33. Bypass pipe; 34. Return pipe; 40. Water pump; 50. Switch valve; 60. Check valve; 71. Intermediate temperature sensor; 72. Inlet water temperature sensor; 73. Outlet water temperature sensor; 80. Flow rate sensor. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0031] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0033] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0034] like Figure 1 As shown, this embodiment provides a gas water heater, including a shell 10, a burner (not shown in the figure) disposed in the shell 10, a heat exchange component 20, and a water circuit component. The water circuit component includes an inlet pipe 31 and an outlet pipe 32. Both the inlet pipe 31 and the outlet pipe 32 are connected to the heat exchange component 20, so that the water entering through the inlet pipe 31 can absorb the heat generated by the combustion of the burner in the heat exchange component 20 and be heated. The water with the increased temperature then flows out through the outlet pipe 32.

[0035] To optimize the energy efficiency of the gas water heater, the heat exchange assembly 20 includes a primary heat exchanger 21 and a secondary heat exchanger 22 connected in series. The secondary heat exchanger 22 is connected to the inlet pipe 31, and the primary heat exchanger 21 is connected to the outlet pipe 32. Water in the inlet pipe 31 passes through the primary heat exchanger 21 and the secondary heat exchanger 22 sequentially before flowing out through the outlet pipe 32. This two-stage heat exchange fully utilizes the heat generated by the burner, improving heat utilization and water heating efficiency, thereby enhancing the performance of the gas water heater.

[0036] In this embodiment, the primary heat exchanger 21 is used to absorb the heat generated by the combustion of gas in the burner, and the secondary heat exchanger 22 is used to absorb the heat of the flue gas generated by the combustion of gas, so as to make full use of the heat of the flue gas and avoid heat waste.

[0037] To improve heat utilization, the water in the inlet pipe 31 first enters the secondary heat exchanger 22 to absorb heat from the flue gas for preheating, and then enters the primary heat exchanger 21 to absorb heat generated by combustion for further heating, which is beneficial to improving heat exchange rate and heating efficiency.

[0038] During the use of a gas water heater, there are times when the water is temporarily shut off. When the water is shut off, the burner does not work, but the residual heat of the burner will continue to heat the water in the primary heat exchanger 21, causing the water temperature to rise and forming high-temperature water. When the water heater is restarted, the high-temperature water caused by the water outage and the cold water that enters during the water heater startup process bring an uncomfortable experience to the user, which is the so-called "hot water" problem.

[0039] To solve the above problems, the gas water heater also includes a bypass pipe 33 and a water pump 40. The bypass pipe 33 can connect the outlet pipe 32 and the inlet pipe 31, so that the inlet pipe 31, the secondary heat exchanger 22, the primary heat exchanger 21 and the outlet pipe 32 can be connected in sequence to form an internal circulation channel; the water pump 40 is installed on the circulation channel to drive the fluid flow.

[0040] By setting up a bypass pipe 33 to form an internal circulation channel, on the one hand, the water in the internal circulation channel can be driven to circulate when the gas water heater is turned off, so that the residual heat of the burner can evenly heat the water in the internal circulation channel, avoiding abnormal local water temperature rise and forming overly hot water, and solving the problem of excessively high outlet water temperature when the gas water heater is restarted; on the other hand, the water circulation in the internal circulation channel can heat the cold water in the internal circulation channel, such as some of the cold water located in the inlet pipe 31, avoiding the problem of cold water coming out when the gas water heater is restarted, and providing sufficient heating time for the cold water newly entering the inlet pipe 31, ensuring that the gas water heater can be used immediately and achieving zero cold water.

[0041] In some embodiments, the water pump 40 is mounted on the inlet pipe 31 and located downstream of the connection point between the inlet pipe 31 and the bypass pipe 33. Mounting the water pump 40 on the inlet pipe 31 not only provides power for the flow of water within the internal circulation channel to quickly and evenly mix hot and cold water, but also provides power for the cold water entering the inlet pipe 31 when the gas water heater is running, preventing insufficient water pressure from affecting the water intake of the gas water heater. By mounting the water pump 40 on the inlet pipe 31, the water pump 40 can provide power both during water intake and for mixing water within the internal circulation channel when the gas water heater is turned off, eliminating the need for an additional pump, thus reducing the number of parts and lowering costs.

[0042] In addition, by setting up a secondary heat exchanger 22, not only can the heat of the flue gas be utilized to improve the heat utilization rate, but the secondary heat exchanger 22 can also play the role of a water tank in the prior art. That is, the secondary heat exchanger 22 can store a certain amount of water, increasing the total amount of hot water after mixing. This allows the user to be provided with a certain amount of uniformly heated mixed water when the gas water heater is turned on again, thus providing sufficient heating time for the cold water newly entering the inlet pipe 31 and achieving a continuous and uninterrupted supply of hot water.

[0043] In this embodiment, the secondary heat exchanger 22 includes heat exchange tubes. Compared with the water tank, the heat exchange tubes are smaller in size and have more flexible placement and arrangement, which helps to optimize the overall space, reduce the overall size of the machine, and improve product competitiveness.

[0044] To better utilize the heat of the flue gas, at least some of the heat exchange tubes are installed above the primary heat exchanger 21 so that they can fully contact and exchange heat with the flue gas during its upward flow, thereby improving heat utilization and avoiding heat waste.

[0045] In some embodiments, the heat exchange tube is bent and coiled on the top surface of the first-stage heat exchanger 21. On the one hand, this increases the effective area of ​​the heat exchange tube intercepting the flue gas from above, thereby increasing the contact area between the heat exchange tube and the flue gas and improving the heat exchange effect. On the other hand, coiling the heat exchange tube on the top surface of the first-stage heat exchanger 21 can reduce the space occupied by the heat exchange tube, making the layout of the first-stage heat exchanger 21 and the second-stage heat exchanger 22 more compact, thereby optimizing the layout and reducing the overall size of the unit.

[0046] In some other embodiments, the heat exchange tube can be wrapped around the primary heat exchanger 21 circumferentially to increase the length of the secondary heat exchanger 22 and the area in contact with the flue gas. This not only increases the amount of water in the secondary heat exchanger 22, but also makes better use of the internal space of the gas water heater and reduces the overall size of the unit.

[0047] To increase the driving force of the water pump 40 on the water in the internal circulation channel, the water pump 40 is located at one end of the inlet pipe 31 connected to the bypass pipe 33. That is, the length of the inlet pipe 31 located between the water pump 40 and the bypass pipe 33 is shorter than the length of the inlet pipe 31 located between the secondary heat exchanger 22 and the water pump 40. The driving force of the water pump 40 on the water in the bypass pipe 33 is greater, which is conducive to the smooth start of water flow in the internal circulation channel.

[0048] To enable on / off control of the bypass pipe 33, a switch valve 50 is installed on the bypass pipe 33. The switch valve 50 can be activated when the gas water heater is turned off, so as to connect the inlet pipe 31 and the outlet pipe 32 through the bypass pipe 33.

[0049] Understandably, when the gas water heater is started, the inlet pipe 31 is in a water-flow state. When the gas water heater is turned off, the secondary heat exchanger 22, the primary heat exchanger 21, and the outlet pipe 32 all contain heated water, while the inlet pipe 31 contains unheated cold water. In the off-state, the burner is not running, and its residual heat is limited. To avoid a low mixed water temperature after the water circulation in the internal circulation channel is mixed, the volume of the bypass pipe 33 located between the switch valve 50 and the inlet pipe 31 is smaller than the volume of the bypass pipe 33 located between the switch valve 50 and the outlet pipe 32. This increases the length of the heated hot water stored in the bypass pipe 33, increasing the amount of hot water stored in the internal circulation channel when the gas water heater is turned off, thereby increasing the mixed water temperature. This ensures that when the gas water heater restarts, the outlet water temperature is closer to the user's desired water temperature.

[0050] Optionally, the bypass pipe 33 includes a first bypass pipe section and a second bypass pipe section. The water pump 40 is located at the connection position of the first bypass pipe section and the second bypass pipe section. The first bypass pipe section is connected to the outlet pipe 32, and the second bypass pipe section is connected to the inlet pipe 31. The length and / or flow area of ​​the first bypass pipe section is greater than the length and / or flow area of ​​the second bypass pipe section.

[0051] In some embodiments, the flow areas of the first bypass section and the second bypass section are equal, and the length of the first bypass section is greater than the length of the second bypass section; or, the lengths of the first bypass section and the second bypass section are equal, and the flow area of ​​the first bypass section is greater than the flow area of ​​the second bypass section.

[0052] In some other embodiments, the length of the first bypass pipe section is greater than the length of the second bypass pipe section, and the flow area of ​​the first bypass pipe section is greater than the flow area of ​​the second bypass pipe section, so as to further increase the amount of hot water stored in the bypass pipe 33 when the gas water heater is in the water-off state.

[0053] In order to increase the temperature of the water after mixing in the internal circulation channel, the bypass pipe 33 includes a first bypass pipe section and a second bypass pipe section. The water pump 40 is located at the connection position of the first bypass pipe section and the second bypass pipe section. The first bypass pipe section is connected to the outlet pipe 32, and the second bypass pipe section is connected to the inlet pipe 31. The flow area of ​​the first bypass pipe section is greater than the flow area of ​​the second bypass pipe section.

[0054] To prevent water in the bypass pipe 33 from flowing back to the outlet pipe 32 when the switch valve 50 is opened, a one-way valve 60 is installed on the bypass pipe 33. The one-way valve 60 can prevent the fluid in the bypass pipe 33 from flowing from the inlet pipe 31 to the outlet pipe 32.

[0055] To ensure the water inlet efficiency of the inlet pipe 31, a one-way valve 60 is installed between the on / off valve 50 and the inlet pipe 31. This arrangement results in a shorter bypass pipe 33 between the one-way valve 60 and the inlet pipe 31. When the gas water heater starts to supply water, a small portion of the water entering the inlet pipe 31 will remain in the bypass pipe 33, while most of the water can directly enter the heat exchange component 20, thereby improving the water inlet response speed and avoiding cold water waste.

[0056] The gas water heater also includes a return pipe 34 connected to the internal circulation channel, which is used to connect to the external water supply line. Water flowing into the external water supply line through the outlet pipe 32 can flow into the internal circulation channel through the return pipe 34, and then be reheated by the heat exchange component 20 to reheat the cold water in the external water supply line, achieving zero cold water and improving the user experience.

[0057] To simplify the structure, the water pump 40 is located downstream of the return pipe 34 so that the water pump 40 can drive the water passing through the return pipe 34, so that the return water passes through the inlet pipe 31, the heat exchange assembly 20 and the outlet pipe 32 in sequence.

[0058] In some embodiments, the return pipe 34 is connected to the bypass pipe 33, and the connection point between the return pipe 34 and the bypass pipe 33 is located between the one-way valve 60 and the inlet pipe 31, and the returned water enters the inlet pipe 31 for circulation.

[0059] In some other embodiments, the return pipe 34 is connected to the inlet pipe 31, which also allows the returned water to be heated by the heat exchange component 20 through the inlet pipe 31.

[0060] To facilitate control of the outlet water temperature of the gas water heater, an inlet water temperature detection element 72 is installed on the inlet pipe 31. The inlet water temperature detection element 72 is used to detect the water temperature in the inlet pipe 31 to obtain the inlet water temperature, so as to facilitate control of the burner's operating parameters, such as the burner's power and start-up time, according to the user's required outlet water temperature, so as to make the outlet water temperature more accurate.

[0061] Optionally, a water outlet temperature detection element 73 is provided on the water outlet pipe 32. The water outlet temperature detection element 73 is used to detect the water temperature in the water outlet pipe 32 to detect whether the actual water outlet temperature meets the user's requirements, so as to facilitate the adjustment of the burner's operating parameters according to the actual water outlet temperature.

[0062] To facilitate the adjustment of the outlet water temperature, the gas water heater also includes a control component. The control component is electrically connected to the inlet water temperature detector 72, the outlet water temperature detector 73, and the burner. The temperature detected by the inlet water temperature detector 72 and the outlet water temperature detector 73 is transmitted to the control component. The control component adjusts the operating parameters of the burner according to the received temperature information to achieve feedback regulation and improve the accuracy of the outlet water temperature.

[0063] To better control the water temperature in the internal circulation channel when the water is turned off, an intermediate temperature detection element 71 is installed between the outlet of the secondary heat exchanger 22 and the inlet of the primary heat exchanger 21. The intermediate temperature detection element 71 is communicatively connected to the burner. The intermediate temperature detection element 71 can detect the water temperature after being heated by the secondary heat exchanger 22. When the gas water heater is in the water-off state, the temperature of the mixed water in the internal circulation channel can be obtained based on the water temperature detected by the intermediate temperature detection element 71. When this water temperature is lower than the preset temperature value, the burner starts to heat the water in the internal circulation channel, ensuring that when the gas water heater restarts, the outlet water temperature is close to the user's set temperature, thus better meeting the user's needs.

[0064] Optionally, the intermediate temperature detection element 71, the inlet water temperature detection element 72, and the outlet water temperature detection element 73 are temperature sensors, such as thermistors, as long as they can detect the water temperature.

[0065] To improve the heat utilization efficiency of the secondary heat exchanger 22, a throttling element is provided at the inlet and / or outlet of the secondary heat exchanger 22. The throttling element can slow down the water flow rate entering the secondary heat exchanger 22 so that the water in the secondary heat exchanger 22 can fully exchange heat with the flue gas and improve the utilization rate of the flue gas heat.

[0066] Alternatively, the throttling element can be a capillary tube, a throttling valve, a throttling orifice plate, or a regulating valve, as long as it can control the flow rate of water entering the secondary heat exchanger 22.

[0067] In some embodiments, the secondary heat exchanger 22 includes a secondary heat exchange channel connecting the water inlet pipe 31 and the primary heat exchanger 21. The secondary heat exchange channel is curved and extended to extend its length without changing the overall size of the secondary heat exchanger 22. This is beneficial for sufficient heat exchange and can increase the amount of water stored in the secondary heat exchanger 22 to meet the water demand before the newly entered cold water is heated when the gas water heater is restarted.

[0068] In some embodiments, the flow area of ​​the secondary heat exchange channel can be larger than the flow area of ​​the pipe connecting its inlet and outlet. That is, the flow area of ​​the inlet pipe 31 is smaller than the flow area of ​​the secondary heat exchange channel, and the flow area of ​​the pipe between the secondary heat exchanger 22 and the primary heat exchanger 21 is smaller than the flow area of ​​the secondary heat exchange channel. By increasing the flow area of ​​the secondary heat exchange channel, the amount of water stored in the secondary heat exchanger 22 can be increased, and the flow velocity of the water entering the secondary heat exchange channel can be slowed down, thus ensuring that the water is fully heated.

[0069] In some embodiments, a turbulence-inducing element is provided in the secondary heat exchange channel. The turbulence-inducing element can change the flow state of the water in the secondary heat exchange channel, causing the fluid to generate turbulence or secondary flow, disrupting the laminar flow layer close to the wall, enhancing convective heat transfer, and thus optimizing heat transfer performance.

[0070] Optionally, the turbulence-disrupting element can be a protrusion, baffle, or spiral structure protruding from the inner wall of the secondary heat exchange channel.

[0071] In some embodiments, a flow detection element 80 is provided on the water inlet pipe 31. The flow detection element 80 is used to detect the flow rate in the water inlet pipe 31 to determine whether the gas water heater is taking in water or whether there is a blockage or other malfunction.

[0072] This embodiment also provides a control method for a gas water heater, which can be applied to the aforementioned gas water heater. The control method specifically includes:

[0073] When the gas water heater is started and water is dispensed, the water pump 40 starts to drive the water in the inlet pipe 31 to flow to the heat exchange component 20, thereby producing hot water;

[0074] When the gas water heater is turned off and the water supply stops, the water pump 40 starts to make the water in the internal circulation channel flow, so as to equalize the water temperature in the internal circulation channel and avoid scalding water.

[0075] By activating the water pump 40 when the gas water heater is turned off and the water flow stops, the fluid in the internal circulation channel can be driven to flow, thereby neutralizing the water temperature and preventing the problem of scalding water. In addition, the water pump 40 can provide power for both the cold water entering the gas water heater and the water circulation in the internal circulation channel, eliminating the need for multiple pumps, which helps to simplify the structure and reduce costs.

[0076] After the water circulates in the inner circulation channel, the outlet water temperature of the secondary heat exchanger 22 is detected. When the outlet water temperature is lower than the preset temperature, the gas water heater is ignited and maintained for a preset time so that the heat generated by the burner can heat the water temperature in the inner circulation channel to meet the usage requirements.

[0077] In some embodiments, the preset temperature and preset duration can be fixed values ​​set at the factory. In other embodiments, the preset temperature can be set according to the user-defined target water temperature, for example, 0.5-1 times the user-defined target water temperature, and the preset duration can be set according to the difference between the detected water temperature and the target water temperature, for example, the larger the difference, the longer the preset duration.

[0078] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A gas water heater, characterised in that, include: Burner; The heat exchange assembly (20) includes a primary heat exchanger (21) and a secondary heat exchanger (22) connected in series. The primary heat exchanger (21) is used to absorb the heat generated by the combustion of gas in the burner. The secondary heat exchanger (22) includes heat exchange tubes for absorbing heat from the flue gas. The water circuit assembly includes an inlet pipe (31), an outlet pipe (32), and a bypass pipe (33). The inlet pipe (31) is connected to the secondary heat exchanger (22), the outlet pipe (32) is connected to the primary heat exchanger (21), and the bypass pipe (33) can connect the outlet pipe (32) and the inlet pipe (31) to form an internal circulation channel. A water pump (40) is installed on the inner circulation channel, and the water pump (40) is used to drive the fluid flow.

2. The gas water heater of claim 1, wherein, At least a portion of the heat exchange tubes are disposed above the primary heat exchanger (21).

3. The gas water heater of claim 2, wherein, The heat exchange tube bending disc is located on the top surface of the primary heat exchanger (21); Alternatively, the heat exchange tube may be wrapped around the primary heat exchanger (21) circumferentially.

4. The gas water heater according to any one of claims 1-3, wherein, The water pump (40) is mounted on the water inlet pipe (31).

5. The gas water heater of claim 4, wherein, The water pump (40) is located at one end of the water inlet pipe (31) that connects to the bypass pipe (33).

6. The gas water heater according to any one of claims 1 to 3, wherein, A switching valve (50) is provided on the bypass pipe (33). The volume of the bypass pipe (33) located between the switching valve (50) and the inlet pipe (31) is smaller than the volume of the bypass pipe (33) located between the switching valve (50) and the outlet pipe (32).

7. The gas water heater of claim 6, wherein, The length of the bypass pipe (33) located between the switch valve (50) and the inlet pipe (31) is less than the length of the bypass pipe (33) located between the switch valve (50) and the outlet pipe (32); And / or, the flow area of ​​the bypass pipe (33) located between the switch valve (50) and the inlet pipe (31) is smaller than the flow area of ​​the bypass pipe (33) located between the switch valve (50) and the outlet pipe (32).

8. The gas water heater of claim 6, wherein, A one-way valve is provided on the bypass pipe (33). The one-way valve can prevent the fluid in the bypass pipe (33) from flowing from the inlet pipe (31) to the outlet pipe (32). The one-way valve is located between the switch valve (50) and the inlet pipe (31).

9. The gas water heater according to any one of claims 1-3, wherein, The gas water heater also includes a return pipe (34) connected to the internal circulation channel. The return pipe (34) is used to connect to the external water supply line. The water pump (40) is located downstream of the return pipe (34) to drive the return water flow.

10. The gas water heater according to any one of claims 1-3, wherein, An intermediate temperature detection element (71) is provided between the outlet of the secondary heat exchanger (22) and the inlet of the primary heat exchanger (21), and the intermediate temperature detection element (71) is communicatively connected to the burner.

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