Control method of gas water heater and zero-cold-water gas water heater

Abstract

The invention discloses a zero-cold-water gas water heater and a control method thereof. The control method of the gas water heater comprises the steps that when a zero cold water mode is executed, a bypass pipe is closed, a circulating pump and a combustor are started, water input by a zero cold water pipe enters a heat exchanger through a water tank to be heated, and the heated water in the heat exchanger is output to an external circulating pipeline through a water outlet pipe till the water temperature of an outlet of the water tank reaches a first set temperature value T1; in the normal water using process after the zero cold water mode is executed, after water using is paused, the bypass pipe is opened, and the circulating pump is started, so that water between the heat exchanger and the water tank circularly flows until the water temperature of an outlet of the water tank reaches a second set temperature value T2. Energy consumption is reduced, and the user experience of the zero-cold-water gas water heater is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of household appliances, and in particular relates to a control method for a gas water heater and a zero-cold-water gas water heater. Background Art

[0002] At present, water heaters are household appliances commonly used in people's daily lives. Water heaters are divided into gas water heaters and electric water heaters. Among them, gas water heaters are widely used because of their convenience. Conventional gas water heaters usually include burners, combustion chambers and heat exchangers. The burner burns gas in the combustion chamber to heat the water flowing through the heat exchanger.

[0003] Zero cold water gas water heaters with zero cold water function are widely used because they can heat the water stored in the water pipes. During use, the zero cold water gas water heater will trigger the execution of zero cold water mode according to the user's settings, that is, the water in the external pipeline will circulate into the internal heat exchanger for heating, so that the water in the external pipeline will also reach the user's set temperature.

[0004] However, the zero cold water gas water heater in the prior art usually performs circulation heating on the external pipes of the whole house when executing the zero cold water mode. When the user is using water, after a short water stop, the water temperature of the water inlet pipe drops to the temperature of the tap water pipe. At this time, the zero cold water gas water heater will be triggered to start the zero cold water mode again. In this way, the zero cold water mode will be frequently started due to the decrease in the inlet water temperature, resulting in high energy consumption; and the frequent startup noise is loud, resulting in a poor user experience. In view of this, how to design a water heater technology that reduces energy consumption and improves user experience is a technical problem to be solved by the present invention. Summary of the invention

[0005] The present invention provides a control method for a gas water heater and a zero-cold-water gas water heater, which can reduce energy consumption and improve user experience of the zero-cold-water gas water heater.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: In one aspect, the present invention provides a control method for a gas water heater, wherein the gas water heater is equipped with a burner, a heat exchanger, a circulation pump, a water inlet pipe, a water outlet pipe, a zero-cold water pipe and a water tank, wherein the heat exchanger is connected to the water outlet pipe through a return pipe, the heat exchanger is connected to the water inlet pipe and the zero-cold water pipe through a circulation pump and a water tank, respectively, and a bypass pipe is provided between the return pipe and the inlet of the water tank, comprising: In the zero cooling water mode, the bypass pipe is closed, the circulation pump and the burner are started, and the water input from the zero cooling water pipe enters the heat exchanger through the water tank for heating. The heated water in the heat exchanger is output to the external circulation pipeline through the water outlet pipe until the water temperature at the outlet of the water tank reaches the first set temperature value T1; During normal water use after the zero cooling water mode is terminated, after water use is suspended, the bypass pipe is opened and the circulation pump is started, so that the water circulates between the heat exchanger and the water tank until the water temperature at the outlet of the water tank reaches the second set temperature value T2.

[0007] After executing the zero cold water mode, during the user's normal water use, when the user stops using water, the bypass pipe will be opened and the circulation pump will be controlled to allow the water inside the zero cold water water heater to circulate internally, so as to reduce the frequent startup of the zero cold water mode caused by the water temperature in the water inlet pipe being too low. In this way, the startup frequency of the zero cold water mode can be reduced. On the one hand, it can reduce energy consumption, and on the other hand, it can also reduce the noise generated by starting the burner when executing the zero cold water mode, thereby improving the user experience.

[0008] In one embodiment of the present application, after the user stops using water, the bypass pipe is opened and the circulation pump is started, specifically: After the normal water use time exceeds the first set time t1, after the water use is suspended, the bypass pipe is opened and the circulation pump is started.

[0009] In one embodiment of the present application, the bypass pipe is opened and the circulation pump is started, specifically: when the startup operation time of the circulation pump exceeds the second set time t2 and the water temperature at the outlet of the water tank does not reach the second set temperature value T2, the burner is started until the water temperature at the outlet of the water tank reaches the third set temperature value T3, and then the burner is turned off and the circulation pump is continuously operated until the water temperature at the outlet of the water tank reaches the second set temperature value T2; Among them, T2>T3.

[0010] In one embodiment of the present application, during normal water use after the zero cold water mode is executed, if the water temperature at the water tank outlet is lower than the set start water temperature value Ts after the water use is suspended for more than the third set time t3, the zero cold water mode is executed again; Among them, t3>t 2; T3>Ts; T1>Ts.

[0011] In one embodiment of the present application, the burner is turned off and the circulating pump continues to operate until the water temperature at the outlet of the water tank reaches the second set temperature value T2, specifically: During the shutdown of the burner circulating pump and its continuous operation, if the water temperature at the outlet of the heat exchanger is higher than the fourth set temperature value T4 and the water temperature at the outlet of the water tank is higher than T2, the bypass pipe is first closed and the flow path between the zero cooling water pipe and the circulating pump is opened. After the circulating pump starts running for a period greater than the fourth time period t4, the bypass pipe is opened and the flow path between the zero cooling water pipe and the circulating pump is closed. The circulating pump continues to run until the water temperature at the outlet of the heat exchanger is lower than T5 and the water temperature at the outlet of the water tank is higher than T2.

[0012] Among them, t3>t4; T4>T5>T2.

[0013] In another aspect, the present invention further provides a zero-cold-water gas water heater, the zero-cold-water gas water heater executing the above-mentioned control method of the gas water heater; The zero cold water gas water heater comprises: A shell, wherein a zero-cold water pipe is provided on the shell; A burner, the burner is used to burn gas; A heat exchanger, wherein the heat exchanger is used for water flow heat exchange; A water inlet and outlet assembly, the water inlet and outlet assembly comprising a water pump, a water tank, a first electrically controlled valve, a water inlet pipe, a water outlet pipe, a water return pipe and a bypass pipe, the water tank being connected to the inlet of the water pump, the water inlet pipe being connected to the water tank, the bypass pipe being connected between the first electrically controlled valve and the water tank, the water outlet pipe being connected to the water return pipe, and the first electrically controlled valve being configured to control the water return pipe to selectively communicate with the bypass pipe; The outlet of the water pump is connected to the inlet of the heat exchanger, the outlet of the heat exchanger is connected to the return pipe, and the zero-cold water pipe is connected to the water tank.

[0014] In one embodiment of the present application, a multi-way connector is provided on the water tank, and the multi-way connector has a first interface, a second interface, a third interface and a fourth interface, the first interface is connected to the water tank, the second interface is connected to the water inlet pipe, and the third interface is connected to the bypass pipe; the fourth interface is connected to the zero-cold water pipe, a second electrically-controlled valve is provided between the water inlet pipe and the second interface, and a third electrically-controlled valve is provided between the zero-cold water pipe and the fourth interface.

[0015] In one embodiment of the present application, the heat exchanger comprises: A heat exchange shell, wherein a smoke inlet and a smoke outlet are arranged on the heat exchange shell, a first air guide plate is arranged in the heat exchange shell, the first air guide plate covers below the smoke outlet, a gap is formed between the first air guide plate and the smoke outlet, a fixed end of the first air guide plate is arranged on the inner wall of the heat exchange shell, and a free end of the first air guide plate is arranged with a flange structure extending downward; A heat exchange tube, wherein the heat exchange tube is arranged in the heat exchange shell, the heat exchange tube is located below the first air guide plate, one pipe opening of the heat exchange tube is connected to the outlet of the water pump, and the other pipe opening of the heat exchange tube is connected to the return water pipe.

[0016] In one embodiment of the present application, a second air guide plate is provided in the heat exchange shell, the second air guide plate covers the top of the smoke inlet and is located at the bottom of the first air guide plate, a plurality of second ventilation holes are provided on the second air guide plate, and the heat exchange tube is located between the second air guide plate and the flange structure.

[0017] In one embodiment of the present application, a one-way valve is provided between the first electrically controlled valve and the bypass pipe, and the one-way valve is configured to restrict the water in the bypass pipe from flowing in one direction toward the water tank.

[0018] By configuring a water tank at the inlet of the water pump, the water tank is connected to the water inlet pipe on the one hand, and is also connected to the first electric control valve through a bypass pipe. During use, when the user turns on the gas water heater and then turns off the water for a short period of time, the water pipe is switched back to the bypass pipe through the first electric control valve, and the water pump is started to allow the water inside the gas water heater to circulate between the heat exchanger and the water tank, and then the waste heat of the heat exchanger is used to heat the water in the water tank. When the user uses the water for the second time, the hot water in the water tank will enter the heat exchanger during the delayed ignition of the gas water heater, so that the water outlet pipe can output relatively constant temperature hot water, thereby reducing the temperature fluctuation of the secondary boiling water and improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 A schematic structural diagram of an embodiment of a zero cold water gas water heater of the present invention; Figure 2 for Figure 1 One of the partial structural diagrams without the outer shell; Figure 3 for Figure 1 The second schematic diagram of the partial structure without the outer shell; Figure 4 for Figure 1 Structural schematic diagram of the water inlet and outlet components; Figure 5 for Figure 1 Schematic diagram of the structure of the water tank; Figure 6 for Figure 1 Cross-sectional view of the grey water tank; Figure 7 It is a flow path principle diagram of another embodiment of the zero cold water gas water heater of the present invention; Figure 8 for Figure 1 A schematic diagram of the structure of the heat exchanger; Fig. 9 for Figure 8 A cross-sectional view of an embodiment of a heat exchanger; Fig.10 for Figure 8 An exploded view of an embodiment of a heat exchanger; Fig.11 for Figure 8 A partial cross-sectional view of the middle heat exchange shell; Fig.12 for Figure 8 Schematic diagram of the local structure of the heat exchange shell; Fig.13 The figure is a flow chart of the control method of the gas water heater of the present invention.

[0021] Description of reference numerals: Shell 1000, zero cooling water pipe 1001; Burner 2000; Heat exchanger 3000; Combustion chamber 4000; Water inlet and outlet components 5000; A water pump 5100, a water tank 5200, a first electrically controlled valve 5300, a water inlet pipe 5400, a water outlet pipe 5500, a water return pipe 5600, a bypass pipe 5700, and a multi-way connector 5800; Barrel body 5210, end cover 5220, first connecting pipe 5230, second connecting pipe 5240, water shield 5250, mounting bracket 5260, one-way valve 5310; Detection module 6000 , water flow sensor 6100 , first water temperature sensor 6200 , second water temperature sensor 6300 . DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0024] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0026] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0027] A gas water heater is a water heater that uses gas as the main energy material and transfers the high-temperature heat generated by gas combustion to cold water flowing through a heat exchanger to prepare hot water.

[0028] A gas water heater generally comprises a shell, and components such as a burner, a heat exchanger, a fan and a fan cover arranged in the shell.

[0029] The gas is transported to the burner and ignited by an ignition device, so that the burner burns the transported gas to generate heat.

[0030] A heat exchange tube is arranged in the heat exchanger, one end of the heat exchange tube is connected to the water supply pipeline, and the other end of the heat exchange tube is connected to a shower head or a faucet.

[0031] The heat generated by the burner burning gas is used to heat the heat exchange tubes, so that the water temperature in the heat exchange tubes is increased to form hot water.

[0032] When the gas water heater is working, cold water provided by the water supply pipeline flows into the heat exchange tube, and then is heated into hot water by the heating source generated by the burner, and then flows out from the shower or faucet through the hot water valve for user use.

[0033] At the same time, when the gas water heater is working, the fan is powered on and runs at the same time. Under the action of the fan, the smoke generated by the burner is discharged to the outside.

[0034] Since the heat generated by the burner burning gas during operation will be conducted to the outer casing, in order to reduce the heat transfer.

[0035] Embodiment 1, as Fig.13 As shown, this embodiment provides a control method for a gas water heater, wherein the gas water heater is provided with a burner, a heat exchanger, a circulation pump, a water inlet pipe, a water outlet pipe, a zero-cold water pipe and a water tank, wherein the heat exchanger is connected to the water outlet pipe through a return pipe, the heat exchanger is connected to the water inlet pipe and the zero-cold water pipe through a circulation pump and a water tank, respectively, and a bypass pipe is provided between the return pipe and the inlet of the water tank, and wherein the method comprises: In the zero cooling water mode, the bypass pipe is closed, the circulation pump and the burner are started, and the water input from the zero cooling water pipe enters the heat exchanger through the water tank for heating. The heated water in the heat exchanger is output to the external circulation pipeline through the water outlet pipe until the water temperature at the outlet of the water tank reaches the first set temperature value T1; During normal water use after the zero cooling water mode is terminated, after water use is suspended, the bypass pipe is opened and the circulation pump is started, so that the water circulates between the heat exchanger and the water tank until the water temperature at the outlet of the water tank reaches the second set temperature value T2.

[0036] Specifically, after the zero-cold-water gas water heater is powered on and started, it will first execute the zero-cold-water mode. In the zero-cold-water mode, the circulation pump and the burner are started, so that the water in the external pipeline circulates and flows into the heat exchanger to be heated. The specific control method of the zero-cold-water mode can refer to the control process of the gas water heater executing the zero-cold-water mode in the conventional technology, and is not limited here.

[0037] After the zero-cold-water gas water heater executes the zero-cold-water mode, users can use hot water for bathing. Users may temporarily shut off the water supply when using hot water. During this process, due to the low water temperature at the water inlet pipe, conventional technology will execute the zero-cold-water mode again. However, the water temperature in the outlet pipe and the user's water terminal pipeline is still high at this time. Frequent activation of the zero-cold-water mode will increase energy consumption.

[0038] To this end, when the user temporarily shuts off the water use during the use of hot water, the internal circulation mode can be executed, that is, the bypass pipe is opened and the circulation pump is started, so that the water between the heat exchanger and the water tank circulates. In this way, the cold water in the water tank is circulated into the heat exchanger to absorb the waste heat of the heat exchanger, thereby avoiding excessive fluctuations in the outlet water temperature caused by the waste heat of the heat exchanger. At the same time, after the user starts again, the burner will be delayed for a certain period of time to start, and the hot water in the water tank can flow into the heat exchanger and finally output, so as to avoid the conventional technology that cold water enters the heat exchanger without being heated and output from the water outlet pipe, causing excessive fluctuations in the outlet water temperature.

[0039] In some embodiments, in order to avoid frequent activation of the internal circulation during use, after the user stops using water, the bypass pipe is opened and the circulation pump is started, specifically: After the normal water use time exceeds the first set time t1, after the water use is suspended, the bypass pipe is opened and the circulation pump is started.

[0040] Specifically, during the user's water use process, if the water use time exceeds the set first set time t1, at this time, after the user finishes using the water and turns off the water, the zero cold water gas water heater will trigger the execution of the internal circulation mode. In this way, it can avoid the waste of extra energy caused by the frequent activation of the internal circulation mode during the user's frequent start and stop of water use.

[0041] In another embodiment, the bypass pipe is opened and the circulation pump is started, specifically: when the startup running time of the circulation pump exceeds the second set time t2 and the water temperature at the outlet of the water tank has not reached the second set temperature value T2, the burner is started until the water temperature at the outlet of the water tank reaches the third set temperature value T3, and then the burner is turned off and the circulation pump is continuously operated until the water temperature at the outlet of the water tank reaches the second set temperature value T2; wherein, T2>T3.

[0042] Specifically, when the zero-cold-water gas water heater is in the internal circulation mode, the end of the internal circulation mode is triggered by judging the running time of the circulation pump and the outlet water temperature of the water tank, that is, after the circulation pump runs for more than the second set time t2 and the water temperature at the outlet of the water tank exceeds the second set temperature value T2, the internal circulation mode is ended and the circulation pump stops running. In this way, it can be ensured that the water inside the zero-cold-water gas water heater can be fully circulated and mixed evenly.

[0043] Furthermore, during the execution of the internal circulation mode, there is a situation where the water temperature at the outlet of the water tank does not reach the second set temperature value T2 due to the large amount of heat absorbed by the water temperature in the water tank. At this time, it is necessary to start the burner to assist in heating the heat exchanger. Moreover, after the burner is started, the burner is shut down after detecting that the water temperature at the outlet of the water tank exceeds the third set temperature value T3, and the circulation pump continues to run to absorb the residual heat of the heat exchanger so that the water temperature at the outlet of the water tank continues to rise until it exceeds the second set temperature value T2, and then the circulation pump is shut down.

[0044] In some other embodiments, during normal water use after the zero cold water mode is terminated, if the water temperature at the water tank outlet is lower than the set start water temperature value Ts after the water use is suspended for more than the third set time t3, the zero cold water mode is re-executed; Among them, t3>t 2; T3>Ts; T1>Ts.

[0045] Specifically, after the user turns off the water, regardless of whether the internal circulation mode is executed, after the water use is suspended for more than the third set time t3, the temperature drop of the water in the pipeline between the water outlet pipe and the water use terminal will become larger. At this time, the zero cold water mode needs to be executed again.

[0046] In some embodiments, the burner is turned off and the circulating pump continues to run until the water temperature at the outlet of the water tank reaches the second set temperature value T2, specifically: During the shutdown of the burner circulating pump and its continuous operation, if the water temperature at the outlet of the heat exchanger is higher than the fourth set temperature value T4 and the water temperature at the outlet of the water tank is higher than T2, the bypass pipe is first closed and the flow path between the zero cooling water pipe and the circulating pump is opened. After the circulating pump starts running for a period greater than the fourth time period t4, the bypass pipe is opened and the flow path between the zero cooling water pipe and the circulating pump is closed. The circulating pump continues to run until the water temperature at the outlet of the heat exchanger is lower than T5 and the water temperature at the outlet of the water tank is higher than T2.

[0047] Among them, t3>t4; T4>T5>T2.

[0048] Specifically, in the internal circulation mode, when the burner is started for auxiliary heating, there is too much heat generated by the burner, which causes the overall water temperature inside the internal circulation mode to be too high. At this time, a certain amount of cold water can be introduced through the zero-cold water pipe to further reduce the internal water temperature. That is, if the water temperature at the outlet of the heat exchanger is higher than the fourth set temperature value T4 and the water temperature at the outlet of the water tank is higher than T2, the water temperature is too high due to excessive waste heat generated by the heat exchanger caused by the heating of the burner. At this time, the bypass pipe can be closed and the flow path between the zero-cold water pipe and the circulation pump can be opened. Under the action of the circulation pump, a certain amount of cold water can be introduced through the zero-cold water pipe to reduce the overall water temperature of the internal circulation water, and finally the outlet water temperature fluctuates less when the user uses the water again, thereby improving the user experience.

[0049] The specific values ​​of the above-mentioned set temperature and set time can be obtained through experiments according to different machine models, and are not limited here.

[0050] Embodiment 2, as Figure 1-Figure 6 As shown, this embodiment proposes a gas water heater, which at least includes: a shell 1000, a burner 2000, a heat exchanger 3000 and a combustion chamber 4000, and the heat exchanger 3000 is used for water flow heat exchange.

[0051] During assembly, the burner 2000 is installed in the bottom area of ​​the combustion chamber, while the heat exchanger 3000 is installed in the top of the combustion chamber.

[0052] During actual use, after the gas is delivered to the burner 2000 and ignited, the high-temperature flue gas generated by the gas rises to heat the water flowing in the top heat exchanger 3000, and the high-temperature flue gas is finally output to the outside of the shell 1000 through the exhaust pipe.

[0053] In order to realize the function of zero cold water, a zero cold water pipe 1001 is also provided on the housing 1000; Among them, in order to solve the problem of large fluctuations in outlet water temperature caused by the secondary boiling water, the gas water heater includes: The water inlet and outlet assembly 5000 includes a water pump 5100, a water tank 5200, a first electrically controlled valve 5300, an inlet pipe 5400, an outlet pipe 5500, a return pipe 5600 and a bypass pipe 5700. The water tank 5200 is connected to the inlet of the water pump 5100, the inlet pipe 5400 is connected to the water tank 5200, the bypass pipe 5700 is connected between the first electrically controlled valve 5300 and the water tank 5200, the outlet pipe 5500 is connected to the return pipe 5600, and the first electrically controlled valve 5300 is configured to control the return pipe 5600 to selectively communicate with the bypass pipe 5700; Among them, the heat exchanger 3000 and the water inlet and outlet assembly 5000 are arranged in the shell 1000, the outlet of the water pump 5100 is connected to the inlet of the heat exchanger 3000, the outlet of the heat exchanger 3000 is connected to the return pipe 5600, the water inlet pipe 5400 and the water outlet pipe 5500 extend to the outside of the shell 1000, and the zero-cold water pipe is connected to the water tank.

[0054] Specifically, the water inlet pipe 5400 and the water outlet pipe 5500 configured for the water inlet and outlet assembly 5000 are used to connect to the external tap water pipe and the water terminal, and the zero-cold water pipe 1001 is connected to the external pipeline outside the equipment to form a zero-cold water loop.

[0055] During use, when the user uses hot water, the cold water transported by the tap enters the water tank 5200 through the water inlet pipe 5400, and enters the heat exchanger 3000 through the water pump 5100; the water entering the heat exchanger 3000 exchanges heat with the high-temperature flue gas generated by the burner 2000 burning gas to form hot water and flows into the first electric control valve 5300 through the return pipe 5600. Finally, the hot water is output from the water outlet pipe 5500 and flows into the water use terminal, such as a faucet or shower.

[0056] When executing the zero cooling water mode, the water pump 5100 starts the first electric control valve 5300 but does not operate, the return pipe 5600 is not connected to the bypass pipe 5700, and because the user terminal is not turned on, the water pump 5100 causes the water in the external pipeline to enter the water tank through the zero cooling water pipe, and then enters the heat exchanger for heating and recirculation to the external pipeline to achieve the zero cooling water function.

[0057] During use, the user may turn off the water for a short time and then start using the water again, which is called secondary water boiling. Before the user turns on the water for the second time, since a certain amount of hot water is stored in the heat exchanger 3000 and the residual heat of the heat exchanger 3000 will continue to heat the water, in order to fully utilize the residual heat of the heat exchanger 3000 to heat the water and solve the technical problem of water outlet temperature fluctuation caused by secondary water boiling.

[0058] After the user turns off the water for a short time, the first electrically controlled valve 5300 will operate, connecting the return pipe 5600 with the bypass pipe 5700, thereby connecting the heat exchanger 3000, the return pipe 5600, the bypass pipe 5700, the water tank 5200 and the water pump 5100 in sequence to form a closed-loop water circulation flow path, i.e., forming an internal circulation inside the equipment.

[0059] After the first electric control valve 5300 connects the return pipe 5600 with the bypass pipe 5700, the water pump 5100 is started. Under the action of the water pump 5100, the water in the water tank 5200 is input into the heat exchanger 3000. At the same time, the water in the heat exchanger 3000 circulates back to the water tank 5200, and then the heat exchanger 3000 is used to circulate and heat the water in the water tank 5200.

[0060] In this way, when the user uses the water for the second time, the first electric control valve 5300 cuts off the flow path of the return pipe 5600 and the bypass pipe 5700. The burner 2000 will delay ignition. At the same time, under the action of the cold water introduced by the water inlet pipe 5400, the hot water in the water tank 5200 flows into the heat exchanger 3000, thereby realizing a relatively stable output of hot water from the water outlet pipe 5500 to reduce the fluctuation range of the outlet water temperature.

[0061] In addition, after the user turns off the water during use, the water in the water tank 5200 will perform an internal circulation, so that there is a certain amount of hot water in the water tank 5200, so as to make full use of the waste heat of the heat exchanger 3000 and the combustion chamber 4000. Then, when executing the zero cold water mode, the water in the external pipeline can enter the water tank 5200 so that the hot water in the water tank 5200 can participate in the zero cold water flow path, so as to shorten the start-up time of the burner 2000 in the zero cold water mode, which is more conducive to reducing energy consumption.

[0062] By configuring a water tank at the inlet of the water pump, the water tank is connected to the water inlet pipe on the one hand, and is also connected to the first electric control valve through a bypass pipe. During use, when the user turns on the gas water heater and then turns off the water for a short period of time, the return pipe is controlled by the first electric control valve to be connected to the bypass pipe, and the water pump is started to allow the water inside the gas water heater to circulate between the heat exchanger and the water tank, and then the waste heat of the heat exchanger is used to heat the water in the water tank. When the user uses the water for the second time, the hot water in the water tank will enter the heat exchanger during the delayed ignition of the gas water heater, so that the water outlet pipe can output relatively constant temperature hot water, thereby reducing the temperature fluctuation of the secondary boiling water and improving the user experience.

[0063] In one embodiment of the present application, a multi-way connector 5800 is provided on the water tank 5200, and the multi-way connector 5800 has a first interface, a second interface, a third interface and a fourth interface. The first interface is connected to the water tank 5200, the second interface is connected to the water inlet pipe 5400, the third interface is connected to the bypass pipe 5700, and the fourth interface is connected to the zero-cold water pipe 1001.

[0064] Specifically, in order to facilitate the connection between the bypass pipe 5700, the water inlet pipe 5400 and the water tank 5200, a multi-way connector 5800 is provided on the water tank 5200, and the zero cooling water pipe 1001, the bypass pipe 5700 and the water inlet pipe 5400 are respectively connected to the corresponding interfaces of the multi-way connector 5800.

[0065] In one embodiment of the present application, the water tank 5200 includes a barrel body 5210 and two end covers 5220, and the end covers 5220 are sealed on the corresponding ports of the barrel body 5210; a first connecting pipe 5230 and a second connecting pipe 5240 are provided on the barrel body 5210, and the first connecting pipe 5230 is located above the second connecting pipe 5240, the first connecting pipe 5230 is connected to the inlet of the water pump 5100, and the second connecting pipe 5240 is connected to the multi-way connector.

[0066] Specifically, the water tank 5200 is provided with a first connecting pipe 5230 and a second connecting pipe 5240 arranged vertically on its barrel body 5210. The first connecting pipe 5230 located at the top is used to output the water in the water tank 5200, and the second connecting pipe 5240 located at the bottom is used to introduce external water into the water tank 5200.

[0067] In order to improve the hot water output rate of the water tank 5200, the first connecting pipe 5230 and the second connecting pipe 5240 are arranged in a staggered manner, such as the first connecting pipe 5230 is located at one end of the barrel body 5210, and the second connecting pipe 5240 is located at the other end of the barrel body 5210. In this way, when the water is boiled for the second time, the cold water introduced by the water inlet pipe 5400 enters the water tank 5200 through the second connecting pipe 5240, and the water heat in the water tank 5200 can be output through the first connecting pipe 5230 away from the second connecting pipe 5240, so as to improve the hot water output rate.

[0068] In one embodiment, a water shield 5250 is provided at the end of the second connecting pipe 5240 extending into the barrel body 5210, and the water shield 5250 is located above the outlet of the second connecting pipe 5240. Specifically, in order to further improve the hot water output rate of the water tank 5200 and reduce the cold water entering at the initial stage of the secondary water boiling, which lowers the output rate of the upper layer of the water tank 5200, a water shield 5250 is provided on the second connecting pipe 5240, and the water shield 5250 covers the port of the second connecting pipe 5240 located in the barrel 5210, so that the cold water input from the second connecting pipe 5240 is shielded by the water shield 5250 and dispersed to the bottom of the water tank 5200, thereby minimizing the impact on the hot water at the top of the water tank 5200.

[0069] In another embodiment, a mounting bracket 5260 is further provided on the end cover 5220 , and the mounting bracket 5260 is fixed to the back plate of the housing 1000 .

[0070] Specifically, in the process of installing the water tank 5200 into the housing 1000, the water tank 5200 can be directly fixed on the back plate of the housing 1000 through the mounting bracket 5260, thereby facilitating assembly by operators.

[0071] In another embodiment of the present application, a one-way valve 5310 is provided between the first electrically controlled valve 5300 and the bypass pipe 5700 , and the one-way valve 5310 is configured to limit the water in the bypass pipe 5700 from flowing unidirectionally toward the water tank 5200 .

[0072] Specifically, during the self-circulation process before the second water heating of the gas water heater, since the water inlet pipe 5400 and the bypass pipe 5700 are also interconnected through the multi-way connector 5800, in order to prevent the cold water from flowing backward through the bypass pipe 5700 due to the water pressure of the tap water pipe when the water pump 5100 is not started, a one-way valve 5310 can be set between the first electric control valve 5300 and the bypass pipe 5700. The one-way valve 5310 will limit the flow direction of the water flow in the bypass pipe 5700, so that the water in the bypass pipe 5700 will not flow backward. This ensures that after the water pump 5100 is started, the water in the heat exchanger 3000 flows into the water tank 5200 through the bypass pipe 5700.

[0073] In another embodiment, in order to introduce cold water through the zero cooling water pipe 1001 as needed during the internal circulation process, a second electrically controlled valve 5410 may be provided between the water inlet pipe and the second interface, and a third electrically controlled valve 1011 may be provided between the zero cooling water pipe and the fourth interface.

[0074] Specifically, during the internal circulation of secondary water, the water inlet pipe can be closed by the second electric-controlled valve 5410, and the zero-cold water pipe 1001 can be opened by the third electric-controlled valve 1011. After starting the circulation pump 5100, the water in the heat exchanger 3000 is output from the outlet pipe 5500 via the return pipe 5600, and the zero-cold water pipe 1001 introduces cold water into the water tank 5200 and transports it into the heat exchanger 3000.

[0075] In one embodiment of the present application, Figure 7 As shown, the zero-cold-water gas water heater further includes a detection module 6000 , which includes a water flow sensor 6100 disposed between the water pump 5100 and the heat exchanger 3000 , and the water flow sensor is configured to trigger the water pump 5100 to adjust the rotation speed.

[0076] Specifically, the flow sensor can detect the operating status of the zero-cold water gas water heater. During use, when the water supply pressure of the external pipeline decreases, the water flow under normal heating state decreases. At this time, the water flow sensor 6100 detects that the water flow rate drops below the set flow rate value, and will trigger the water pump to start, so as to achieve auxiliary pressure boosting through the water pump, thereby ensuring that the user can use the water heater normally.

[0077] In addition, in order to accurately control the water temperature, the detection module 6000 also includes a temperature sensor, which includes a first water temperature sensor 6200 arranged at the inlet of the heat exchanger, a second water temperature sensor 6300 arranged at the front side of the water inlet of the water tank, and a third water temperature sensor 6300 arranged at the outlet of the heat exchanger.

[0078] During use, since the water tank is located between the first water temperature sensor 6200 and the second water temperature sensor 6300, by collecting the temperature values ​​of the first water temperature sensor 6200 and the second water temperature sensor 6300, the water inlet temperature and the water outlet temperature of the water tank can be known, and then in the secondary water boiling control process, the start and stop of the water pump can be accurately controlled.

[0079] The third water temperature sensor 6300 can detect the temperature of the hot water output by the heat exchanger 3000, and adjust the gas supply of the burner 2000 and the speed of the water pump according to the output hot water temperature, so that the water temperature remains constant. For the specific control method of the water pump and the burner, reference can be made to conventional technology, which will not be limited or elaborated here.

[0080] Embodiment 3: For the zero-cold-water gas water heater in this embodiment, the heat exchanger 3000 used can be a conventional coil heat exchanger. In order to further improve the heat exchange efficiency of the heat exchanger 3000 and reduce the overall energy consumption, the following structural improvement design is performed on the heat exchanger 3000.

[0081] like Figure 8-Figure 12 As shown, the heat exchanger 3000 adopts a condensing heat exchange method, which includes a heat exchange shell 3100, on which a smoke inlet 3101 and a smoke outlet 3102 are arranged, and a first air guide plate 3110 is arranged in the heat exchange shell 3100, the first air guide plate 3110 covers the lower part of the smoke outlet 3102, and a gap is formed between the first air guide plate 3110 and the smoke outlet 3102, the fixed end of the first air guide plate 3110 is arranged on the inner wall of the heat exchange shell 3100, and the free end of the first air guide plate 3110 is provided with a flange structure 3111 extending downward; The heat exchange tube 3200 is disposed in the heat exchange shell 3100 , and the heat exchange tube 3200 is located below the first air guide plate 3110 .

[0082] Specifically, in the actual assembly process, the heat exchange tube 3200 is placed in the heat exchange shell 3100 and arranged below the first air guide plate 3110. During use, the heat exchanger is arranged in the shell of the gas water heater and above the combustion chamber. The high-temperature flue gas generated by the combustion of the gas in the combustion chamber 4000 enters the heat exchange shell 3100 through the flue gas inlet 3101.

[0083] The high-temperature flue gas entering the heat exchange shell 3100 will exchange heat with the heat exchange tube 3200, but the high-temperature flue gas will not be directly output from the top flue gas outlet 3102 due to the blocking restriction of the first air guide plate 3110. Under the action of the first air guide plate 3110, the flue gas is restricted to the bottom of the first air guide plate 3110, so that the flue gas can fully exchange heat with the heat exchange tube 3200. In addition, the free end of the first air guide plate 3110 is provided with a flange structure 3111 extending downward, and the flange structure 3111 can be used to force the flue gas entering the heat exchange shell 3100 to bypass the lower edge of the flange structure 3111 before being output from the flue gas outlet 3102, thereby maximizing the heat exchange time between the flue gas and the heat exchange tube 3200.

[0084] In another embodiment, the heat exchange tube 3200 is a bellows structure. Specifically, the heat exchange tube 3200 can be composed of more than 3 layers of stainless steel bellows, and each layer of the coils is in parallel to reduce the overall water resistance. In addition, a drain pipe (not marked) is also provided on the bottom plate of the heat exchange shell, and the condensed water in the heat exchange shell 3100 is discharged through the drain pipe.

[0085] In one embodiment of the present application, the first air guide plate 3110 extends obliquely downward from the fixed end toward the free end.

[0086] Specifically, in order to reduce the wind resistance of the flue gas and guide the flue gas to flow smoothly in the heat exchange shell 3100, the first air guide plate 3110 is arranged in an inclined manner in the heat exchange shell 3100. The fixed end of the first air guide plate 3110 is located at a higher position. After the flue gas enters the heat exchange shell 3100, it will flow along the first air guide plate 3110 toward the flange structure 3111, and finally bypass the flange structure 3111 to rise to the top of the heat exchange shell 3100 and be output from the flue gas outlet 3102.

[0087] In another embodiment, a plurality of first ventilation holes 3112 are disposed on the first air guide plate 3110 , and the first ventilation holes 3112 are away from the fixed end of the first air guide plate 3110 .

[0088] Specifically, in order to more effectively reduce wind resistance and ensure smooth output of smoke, a plurality of first ventilation holes 3112 are provided on the first air guide plate 3110. During use, part of the smoke can be discharged through the first ventilation holes 3112, while the rest of the smoke bypasses the bottom of the flange structure 3111 and flows to the smoke outlet 3102.

[0089] In some embodiments, the distribution position of the first ventilation holes 3112 may be such that the first ventilation holes 3112 are formed on the flange structure 3111 ; and / or the first ventilation holes 3112 are formed at the free end of the first air guide plate 3110 .

[0090] In another embodiment of the present application, a second air guide plate 3120 is provided in the heat exchange shell 3100, the second air guide plate 3120 covers the top of the smoke inlet 3101 and is located at the bottom of the first air guide plate 3110, a plurality of second ventilation holes 3121 are provided on the second air guide plate 3120, and the heat exchange tube 3200 is located between the second air guide plate 3120 and the flange structure 3111.

[0091] Specifically, in order to effectively disperse the flue gas entering the heat exchange shell 3100 so that it can be more evenly dispersed to various positions of the heat exchange tube 3200, a second air guide plate 3120 is additionally configured in the heat exchange shell 3100, and the second air guide plate 3120 covers the flue gas inlet 3101. In this way, after the flue gas enters through the flue gas inlet 3101, it will be output from the second ventilation hole 3121 and flow horizontally to the heat exchange tube 3200 on one side, and then in the height direction, the flue gas flow rate is evenly distributed to the heat exchange tube 3200, so as to more effectively improve the heat exchange uniformity of the heat exchange tube 3200.

[0092] In one embodiment, the second air guide plate 3120 is an inverted U-shaped structure, and a second ventilation hole 3121 is disposed on a side of the second air guide plate 3120 adjacent to the heat exchange tube 3200 .

[0093] Specifically, the second air guide plate 3120 with an inverted U-shaped structure can effectively cover the top of the smoke inlet 3101. The second air guide plate 3120 forms a buffer zone for the smoke to enter the heat exchange shell 3100. In addition, the second ventilation hole 3121 formed on one side of the second air guide plate 3120 is adjacent to the heat exchange tube 3200, which can ensure that the output smoke directly enters the area where the heat exchange tube 3200 is located, thereby improving the heat exchange efficiency.

[0094] In one embodiment, the smoke inlet 3101 is located below the fixed end of the first air guide plate 3110 , and the second air guide plate 3120 covers the smoke inlet 3101 .

[0095] Specifically, the smoke output from the second ventilation hole 3121 will be transported toward the flange structure 3111, and during the transportation process, the smoke rises and flows onto the first air guide plate 3110, and the smoke is guided by the inclined first air guide plate 3110, thereby ensuring that the smoke can evenly exchange heat with the heat exchange tube 3200 and ensure that the smoke flows smoothly in the heat exchange shell 3100, so as to reduce the influence of wind resistance and ensure smooth smoke exhaust.

[0096] In one embodiment of the present application, an air collecting hood 3300 is further included. A connecting port 3301 is provided on the top of the air collecting hood 3300 . The air collecting hood 3300 is disposed at the bottom of the heat exchange shell 3100 . The connecting port 3301 is connected to the smoke inlet 3101 .

[0097] Specifically, in order to better collect the smoke generated by the combustion chamber in the gas water heater, an air collecting hood 3300 is configured at the bottom of the heat exchange shell 3100. The air collecting hood 3300 can better cooperate with the top of the combustion chamber to collect the smoke and guide the smoke into the heat exchange shell 3100.

[0098] Compared with the prior art, the advantages and positive effects of the present invention are: a first air guide plate is arranged in the heat exchange shell to shield the bottom of the smoke outlet, and a flange structure is also arranged on the first air guide plate. During use, the smoke enters the heat exchange shell through the smoke inlet and contacts and exchanges heat with the heat exchange tube below the first air guide plate. During the rising process, the smoke is restricted by the first air guide plate and cannot continue to rise and is further restricted by the flange structure, so that the smoke has a tendency to flow downward in the heat exchange shell. In this way, the smoke can fully exchange heat with the heat exchange tube below the first air guide plate, so as to improve the heat exchange efficiency of the heat exchanger and reduce the energy consumption of the gas water heater.

[0099] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected by the present invention.

Claims

1. A control method for a gas water heater, wherein the gas water heater is equipped with a burner, a heat exchanger, a circulation pump, a water inlet pipe, a water outlet pipe, a zero-cold water pipe and a water tank, wherein the heat exchanger is connected to the water outlet pipe through a return pipe, the heat exchanger is connected to the water inlet pipe and the zero-cold water pipe through a circulation pump and a water tank, respectively, and a bypass pipe is provided between the return pipe and the inlet of the water tank, wherein the method comprises: include: In the zero cooling water mode, the bypass pipe is closed, the circulation pump and the burner are started, and the water input from the zero cooling water pipe enters the heat exchanger through the water tank for heating. The heated water in the heat exchanger is output to the external circulation pipeline through the water outlet pipe until the water temperature at the outlet of the water tank reaches the first set temperature value T1; During normal water use after the zero cooling water mode is terminated, after water use is suspended, the bypass pipe is opened and the circulation pump is started, so that the water circulates between the heat exchanger and the water tank until the water temperature at the outlet of the water tank reaches the second set temperature value T2.

2. The control method of the gas water heater according to claim 1, characterized in that: After the user stops using water, open the bypass pipe and start the circulation pump, specifically: After the normal water use time exceeds the first set time t1, after the water use is suspended, the bypass pipe is opened and the circulation pump is started.

3. The control method of the gas water heater according to claim 1, characterized in that: Open the bypass pipe and start the circulation pump, specifically: when the startup running time of the circulation pump exceeds the second set time t2 and the water temperature at the outlet of the water tank does not reach the second set temperature value T2, start the burner until the water temperature at the outlet of the water tank reaches the third set temperature value T3, then turn off the burner and keep running the circulation pump until the water temperature at the outlet of the water tank reaches the second set temperature value T2; Among them, T2>T3.

4. The control method of the gas water heater according to claim 3, characterized in that: During normal water use after the zero cold water mode is terminated, if the water temperature at the water tank outlet is lower than the set start water temperature value Ts after the water use is suspended for more than the third set time t3, the zero cold water mode is re-executed; Among them, t3>t 2; T3>Ts; T1>Ts.

5. The control method of the gas water heater according to claim 3, characterized in that: The burner is turned off and the circulating pump continues to run until the water temperature at the outlet of the water tank reaches the second set temperature value T2, specifically: During the continuous operation of the burner circulation pump after shutting down, if the water temperature at the outlet of the heat exchanger is higher than the fourth set temperature value T4 and the water temperature at the outlet of the water tank is higher than T2, the bypass pipe is first closed and the flow path between the zero cooling water pipe and the circulation pump is opened. After the circulation pump is started and operated for a time period greater than the fourth time period t4, the bypass pipe is opened and the flow path between the zero cooling water pipe and the circulation pump is closed. The circulation pump continues to operate until the water temperature at the outlet of the heat exchanger is lower than T5 and the water temperature at the outlet of the water tank is higher than T2. Among them, t3> t4; T4> T5>T2.

6. A zero cold water gas water heater, characterized in that: The zero-cold-water gas water heater implements the control method of the gas water heater according to any one of claims 1 to 5; The zero cold water gas water heater comprises: A shell, wherein a zero-cold water pipe is provided on the shell; A burner, the burner is used to burn gas; A heat exchanger, wherein the heat exchanger is used for water flow heat exchange; A water inlet and outlet assembly, the water inlet and outlet assembly comprising a water pump, a water tank, a first electrically controlled valve, a water inlet pipe, a water outlet pipe, a water return pipe and a bypass pipe, the water tank being connected to the inlet of the water pump, the water inlet pipe being connected to the water tank, the bypass pipe being connected between the first electrically controlled valve and the water tank, the water outlet pipe being connected to the water return pipe, and the first electrically controlled valve being configured to control the water return pipe to selectively communicate with the bypass pipe; The outlet of the water pump is connected to the inlet of the heat exchanger, the outlet of the heat exchanger is connected to the return pipe, and the zero-cold water pipe is connected to the water tank.

7. The zero cold water gas water heater according to claim 6, characterized in that: The water tank is provided with a multi-way connector, which has a first interface, a second interface, a third interface and a fourth interface. The first interface is connected to the water tank, the second interface is connected to the water inlet pipe, and the third interface is connected to the bypass pipe; the fourth interface is connected to the zero-cold water pipe, a second electrically-controlled valve is provided between the water inlet pipe and the second interface, and a third electrically-controlled valve is provided between the zero-cold water pipe and the fourth interface.

8. The zero cold water gas water heater according to claim 6, characterized in that: The heat exchanger comprises: A heat exchange shell, wherein a smoke inlet and a smoke outlet are arranged on the heat exchange shell, a first air guide plate is arranged in the heat exchange shell, the first air guide plate covers below the smoke outlet, a gap is formed between the first air guide plate and the smoke outlet, a fixed end of the first air guide plate is arranged on the inner wall of the heat exchange shell, and a free end of the first air guide plate is arranged with a flange structure extending downward; A heat exchange tube, wherein the heat exchange tube is arranged in the heat exchange shell, the heat exchange tube is located below the first air guide plate, one pipe opening of the heat exchange tube is connected to the outlet of the water pump, and the other pipe opening of the heat exchange tube is connected to the return water pipe.

9. The zero cold water gas water heater according to claim 8, characterized in that: A second air guide plate is arranged in the heat exchange shell, the second air guide plate covers the top of the smoke inlet and is located at the bottom of the first air guide plate, a plurality of second ventilation holes are arranged on the second air guide plate, and the heat exchange tube is located between the second air guide plate and the flange structure.

10. The zero cold water gas water heater according to claim 6, characterized in that: A one-way valve is provided between the first electrically controlled valve and the bypass pipe, and the one-way valve is configured to restrict the water in the bypass pipe from flowing toward the water tank in one direction.

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