Control method of gas water heater and gas water heater

Abstract

The present application relates to the technical field of water heaters, and specifically discloses a control method of a gas water heater and the gas water heater. The gas water heater comprises a main heat exchanger, a condensing heat exchanger, a water inlet main pipe, an atomizer and a water path switching assembly. The atomizer atomizes condensate water. In the water path switching assembly, a first water path directly connects the water inlet main pipe and the main heat exchanger, and a second water path sequentially connects the water inlet main pipe, the condensing heat exchanger and the main heat exchanger. When the atomizer is not faulty, the water path switching assembly works in a first mode, so that the first water path is closed and the second water path is opened. When the atomizer is faulty, the water path switching assembly works in a second mode, so that the first water path and the second water path are opened. In the second mode, the amount of cold water flowing into the condensing heat exchanger is reduced, the generation speed of condensate water is reduced, the condensate water level grows slowly, and even does not grow under the evaporation of high-temperature flue gas. The time for a user to normally use hot water can be prolonged, and thus the user experience is improved.

Description

Technical Field

[0001] This invention relates to the field of water heater technology, and more particularly to a control method for a gas water heater and a gas water heater. Background Technology

[0002] In the water heater with a condensing heat exchanger disclosed in existing patent document (CN120868618A), the water circuit switching component connects the inlet main pipe, the condensing heat exchanger, and the main heat exchanger sequentially in the first operating mode to form a first flow path. In the second operating mode, the water circuit switching component connects the inlet main pipe to the main heat exchanger to form a second flow path, and disconnects the inlet and / or outlet of the condensing heat exchanger from the second flow path. When the water circuit switching component operates in the first operating mode, the condensing heat exchanger works normally and produces condensate. When the liquid level in the water collection chamber reaches a first preset level, the atomization module is activated to atomize the condensate in the water collection chamber and discharge it through the exhaust port. When the liquid level in the water collection chamber reaches a second preset level and there is a risk of backflow, the water circuit switching component switches to the second operating mode. The condensing heat exchanger stops producing condensate, and the exhaust temperature increases, which helps to atomize and discharge the residual condensate in the water collection chamber, reducing the liquid level in the water collection chamber and ensuring combustion safety.

[0003] The water heater disclosed in the aforementioned patent documents does not have a method for handling atomizer malfunctions. However, after an atomizer malfunctions, the condensate level will quickly reach the shutdown level. When the condensate level reaches the shutdown level, the gas water heater will directly shut down the entire unit to prevent condensate from flowing back into the combustion chamber of the water heater body due to excessively high condensate levels. This means that if an atomizer malfunctions while the user is showering, they will soon be unable to use hot water normally, resulting in a poor user experience. Summary of the Invention

[0004] One of the technical problems solved by this invention is to provide a control method for a gas water heater that can extend the time for users to use hot water normally when the atomizer malfunctions, thereby improving the user experience.

[0005] The second technical problem solved by this invention is to provide a gas water heater that can extend the time for users to use hot water normally when the atomizer malfunctions, thereby improving the user experience.

[0006] The first technical problem mentioned above is solved by the following technical solution:

[0007] A control method for a gas water heater, the gas water heater comprising a main heat exchanger, a condensing heat exchanger, a main inlet pipe, an atomizer, and a water circuit switching assembly, wherein the condensing heat exchanger has a water collection chamber for collecting condensate generated by the condensing heat exchanger, and the atomizer is used to atomize the condensate; the water circuit switching assembly comprises a first water circuit and a second water circuit, the first water circuit being used to directly connect the main inlet pipe to the main heat exchanger, and the second water circuit being used to sequentially connect the main inlet pipe, the condensing heat exchanger, and the main heat exchanger; the control method includes:

[0008] After the gas water heater has been operating, determine whether the atomizer is faulty;

[0009] If not, control the water circuit switching component to operate in the first mode, in which the first water circuit is closed and the second water circuit is open;

[0010] If so, control the water path switching component to operate in the second mode, in which the first water path and the second water path are opened.

[0011] The control method for gas water heaters described in this invention has the following advantages compared to the prior art:

[0012] When the atomizer of a gas water heater is functioning normally, the water circuit switching component operates in mode one, closing the first water circuit and opening the second. This allows the condenser heat exchanger to operate at high thermal efficiency, recovering heat from the flue gas and effectively improving the overall heat exchange efficiency of the gas water heater. When the atomizer malfunctions and cannot atomize the condensate, the water circuit switching component operates in mode two, opening both the first and second water circuits. A portion of the cold water is diverted through the first water circuit, reducing the amount of cold water flowing into the condenser heat exchanger. This slows down the condensate formation rate, resulting in a slower condensate level rise, or even no rise at all due to the evaporation of high-temperature flue gas. This prolongs the time it takes for the condensate level to reach the shutdown level, while the condenser heat exchanger continues to recover residual heat from the flue gas. Therefore, the gas water heater does not shut down rapidly when the atomizer malfunctions, extending the time users can enjoy hot water normally and improving the user experience.

[0013] The second technical problem mentioned above is solved by the following technical solution:

[0014] A gas water heater includes a main heat exchanger, a condensing heat exchanger, a main inlet pipe, an atomizer, a water circuit switching assembly, and a controller. The water circuit switching assembly is communicatively connected to the controller. The condensing heat exchanger has a water collection chamber for collecting condensate generated by the condensing heat exchanger. The atomizer atomizes the condensate. The water circuit switching assembly includes a first water circuit and a second water circuit. The first water circuit directly connects the main inlet pipe to the main heat exchanger. The second water circuit sequentially connects the main inlet pipe, the condensing heat exchanger, and the main heat exchanger. The controller executes the control method for the gas water heater described in this invention.

[0015] Compared with the prior art, the gas water heater of the present invention has the following beneficial effects:

[0016] When the atomizer of a gas water heater is functioning normally, the water circuit switching component operates in mode one, closing the first water circuit and opening the second. This allows the condenser heat exchanger to operate at high thermal efficiency, recovering heat from the flue gas and effectively improving the overall heat exchange efficiency of the gas water heater. When the atomizer malfunctions and cannot atomize the condensate, the water circuit switching component operates in mode two, opening both the first and second water circuits. A portion of the cold water is diverted through the first water circuit, reducing the amount of cold water flowing into the condenser heat exchanger. This slows down the condensate formation rate, resulting in a slower condensate level rise, or even no rise at all due to the evaporation of high-temperature flue gas. This prolongs the time it takes for the condensate level to reach the shutdown level, while the condenser heat exchanger continues to recover residual heat from the flue gas. Therefore, the gas water heater does not shut down rapidly when the atomizer malfunctions, extending the time users can enjoy hot water normally and improving the user experience.

[0017] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of a control method for a gas water heater provided in Embodiment 1 of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the gas water heater provided by the present invention;

[0021] Figure 3 This is a schematic diagram of the water flow when the water path switching component is in the first and second modes;

[0022] Figure 4 This is a flowchart of a control method for a gas water heater provided in Embodiment 2 of the present invention;

[0023] Figure 5 This is a schematic diagram of a water flow regulating valve installed in a water system;

[0024] Figure 6 This is a flowchart of a control method for a gas water heater provided in Embodiment 3 of the present invention;

[0025] Figure 7 This is a schematic diagram of a liquid level probe detecting the liquid level;

[0026] Figure 8 This is a schematic diagram of a guide rod type float level detection device for detecting liquid level. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0028] Example 1

[0029] Figure 1 A flowchart of a control method for a gas water heater provided in Embodiment 1 of the present invention is shown below. Figure 1 As shown, the control method of this gas water heater includes:

[0030] S101. After the gas water heater is working, determine whether the atomizer is faulty.

[0031] The gas water heater in this embodiment is a water heater with a condensing heat exchanger, which recovers heat from the flue gas generated by gas combustion. Figure 2As shown, a gas water heater may include a main heat exchanger 1, a condensing heat exchanger 2, a main inlet pipe 3, an atomizer 4, a water circuit switching component 5, and a controller 6. The main heat exchanger 1 is the main component used to realize combustion and heat exchange. The flue gas generated by combustion in the main heat exchanger 1 enters the condensing heat exchanger 2 through the flue 7. The flue gas exchanges heat with the heat exchange tubes in the condensing heat exchanger 2 to realize the recovery of flue gas heat. At the same time, condensate is generated and collected by the water collection chamber 21 in the condensing heat exchanger 2. The atomizer 4 is used to atomize the condensate in the water collection chamber 21 and discharge it into the atmosphere. The cold water flowing into the condensing heat exchanger 2 increases in temperature after heat exchange and then flows into the main heat exchanger 1.

[0032] The water path switching component 5 is communicatively connected to the controller 6. The water path switching component 5 includes a first water path and a second water path. The first water path directly connects the main inlet pipe 3 to the main heat exchanger 1. The second water path sequentially connects the main inlet pipe 3, the condenser heat exchanger 2, and the main heat exchanger 1. In one embodiment, as shown... Figure 2 As shown, the water circuit switching component 5 includes a first pipe 52, a second pipe 53, a third pipe 54, and a water circuit switching valve 51. The water circuit switching valve 51 is connected to the main water inlet pipe 3 and is communicatively connected to the controller 6. The first pipe 52 is connected to the inlet of the condensing heat exchanger 2 and the water circuit switching valve 51. The second pipe 53 is connected to the outlet of the condensing heat exchanger 2 and the inlet of the main heat exchanger 1. That is, the first pipe 52, the condensing heat exchanger 2, and the second pipe 53 are connected in sequence to form the second water circuit. The third pipe 54 is connected to the water circuit switching valve 51 and the inlet of the main heat exchanger 1 to form the first water circuit. The controller 6 can control the water circuit switching valve 51 to close and open the first water circuit and the second water circuit.

[0033] Atomizer malfunction refers to the atomizer's inability to atomize condensed water. In one embodiment, the atomizer is communicatively connected to a controller. The controller receives current signal values ​​fed back by the atomizer. If the deviation between the current signal value and a preset current signal value exceeds a preset threshold, the atomizer is determined to be faulty. In another embodiment, the atomizer malfunction can also be determined by changes in the condensed water level. For example, the second water path can be shut off to prevent the condenser heat exchanger from producing condensed water. If the condensed water level does not drop within a preset time, the atomizer is determined to be faulty and unable to atomize the condensed water. If the atomizer is determined not to be faulty, step S102 is executed; if the atomizer is faulty, step S103 is executed.

[0034] S102. The water circuit switching component is controlled to operate in the first mode. In the first mode, the first water circuit is closed and the second water circuit is opened.

[0035] like Figure 3Part (a) shows a schematic diagram of the state of the first water path and the second water path in the first mode. In the first mode, the second water path is open and the first water path is closed. The cold water in the main water inlet pipe 3 enters the condenser heat exchanger 2 after being heated by the water path switching valve 51 and then flows into the main heat exchanger 1. In one embodiment, the water path switching valve 51 can be a three-way valve, which can connect the main water inlet pipe 3, the first water path and the second water path. When the atomizer is not faulty, the controller 6 controls the three-way valve to open the second water path and close the first water path. The cold water only flows into the main heat exchanger 1 after passing through the condenser heat exchanger 2, and will not flow directly into the main heat exchanger 1 through the first water path. The cold water is completely heated by the condenser heat exchanger 2 before entering the main heat exchanger 1. The condenser heat exchanger 2 recovers the heat in the flue gas with high efficiency. Since the atomizer is not faulty and has sufficient atomization capacity, the condensate is atomized and discharged into the atmosphere by the atomizer, which can effectively control the condensate level within a safe range.

[0036] S103, The water circuit switching component is controlled to operate in the second mode. In the second mode, the first water circuit and the second water circuit are opened.

[0037] like Figure 3 As shown in section (b), the controller can control the water circuit switching valve 51, so that both the first and second water circuits are opened. A portion of the cold water in the main inlet pipe 3 flows into the main heat exchanger 1 after passing through the condenser heat exchanger 2, while a portion of the cold water flows directly into the main heat exchanger 1 through the first water circuit. Figure 3 In part (a) of the diagram, the reduced flow of cold water from the main inlet pipe 3 into the condenser heat exchanger 2 slows down the condensate generation rate, resulting in a slower condensate level rise or even no rise at all due to the evaporation of high-temperature flue gas. This prolongs the time it takes for the condensate level to reach the shutdown level, while the condenser heat exchanger continues to recover waste heat from the flue gas. Therefore, the gas water heater will not shut down rapidly when the atomizer malfunctions, extending the time users can normally use hot water and improving the user experience.

[0038] Understandably, in the second mode, further controlling the condensate generation rate to be less than or equal to the evaporation rate of the condensate by the flue gas ensures that the condensate level is reduced. In other words, by setting the second mode to deal with atomizer failure, the gas water heater does not need to shut down completely when the atomizer fails, allowing users to use hot water normally.

[0039] Example 2

[0040] Figure 4 This is a flowchart of a control method for a gas water heater provided in Embodiment 2 of the present invention. This embodiment of the present invention is an optimization based on Embodiment 1 described above, such as... Figure 4 As shown, the control method of this gas water heater includes:

[0041] S401. After the gas water heater is working, determine whether the atomizer is faulty.

[0042] In one embodiment, the atomizer is communicatively connected to the controller. The controller receives the current signal value fed back by the atomizer and determines whether the deviation between the current signal value and the preset current signal value is greater than a preset threshold. If yes, the atomizer is determined to be faulty, and S403-S405 are executed. If no, the atomizer is determined to be not faulty, and S402 is executed.

[0043] In another optional embodiment, the liquid level growth rate of the condensate in the water collection chamber when the atomizer is working can be obtained, and when the liquid level growth rate is greater than a preset growth rate, the atomizer is determined to be faulty.

[0044] S402, The water circuit switching component is operated in the first mode. In the first mode, the first water circuit is closed and the second water circuit is open.

[0045] like Figure 3 Part (a) shows the state diagram of the first water path and the second water path in the first mode. The water path switching valve 51 can be a three-way valve, which can connect the main water inlet pipe 3, the first water path and the second water path. When the atomizer is not faulty, the controller 6 controls the three-way valve to open the second water path and close the first water path. The cold water flows into the main heat exchanger 1 only after passing through the condenser heat exchanger 2, and will not flow directly into the main heat exchanger 1 through the first water path. The cold water is completely heated by the condenser heat exchanger 2 before entering the main heat exchanger 1. The condenser heat exchanger 2 recovers the heat in the flue gas with high efficiency. Since the atomizer is not faulty and has sufficient atomization capacity, the condensate water is atomized and discharged into the atmosphere through the atomizer, which can effectively control the condensate water level within a safe range.

[0046] S403, The water circuit switching component is operated in the second mode, in which the first water circuit and the second water circuit are opened.

[0047] In one optional embodiment, when it is determined that the atomizer changes from a normal operating state to a fault state, the water flow rate of the second water path is adjusted so that the condensate generation rate is less than the evaporation rate of the condensate by the flue gas. Condensate generation occurs when the high-temperature flue gas exchanges heat with the cold water in the heat exchange tubes of the condenser, causing the flue gas temperature to reach the dew point and condense to form condensate. Condensate evaporation occurs when the condensate is heated and evaporated under the high-temperature flue gas. Specifically, the second water path is equipped with a water flow regulating valve, and the water flow rate of the second water path can be adjusted by adjusting the opening of the water flow regulating valve.

[0048] like Figure 3 As shown in section (b), the controller can control the water circuit switching valve 51, so that both the first and second water circuits are opened. A portion of the cold water in the main inlet pipe 3 flows into the main heat exchanger 1 after passing through the condenser heat exchanger 2, while a portion of the cold water flows directly into the main heat exchanger 1 through the first water circuit. Figure 3 In part (a), the amount of cold water flowing into the condenser heat exchanger 2 from the main water inlet pipe 3 is reduced, which reduces the rate of condensate generation in the condenser heat exchanger 2. At the same time, the condensate evaporates under the high temperature flue gas. When the rate of condensate generation is less than or equal to the rate of evaporation of condensate by the flue gas, it can ensure that the condensate level is reduced to a safe range. That is, by setting the second mode to deal with atomizer failure, the condensate level can be reduced to a safe range. The gas water heater does not need to shut down the whole machine when the atomizer fails, so that users can use hot water normally.

[0049] S404. Determine whether the condensate level is rising based on the real-time condensate level.

[0050] This embodiment can detect the real-time liquid level of condensate using various level gauges, such as level gauges with probe structures, level gauges with float structures, or other types of level gauges. After the water path switching component is operating in the second mode, it can be determined whether the real-time liquid level of condensate is rising. Specifically, the current detected liquid level value can be compared with the previously detected liquid level value to determine whether the liquid level is rising. If so, it means that the condensate generation rate is greater than the evaporation rate of condensate by flue gas, and S405 can be executed. If not, it means that the condensate generation rate is less than or equal to the evaporation rate of condensate by flue gas, and the minimum water passage area of ​​the second water path can remain unchanged.

[0051] S405. Reduce the minimum water flow area of ​​the second water channel so that the rate of condensate generation is less than the rate of condensate evaporation by flue gas.

[0052] In one optional embodiment, the minimum water passage area of ​​the second water channel can be gradually reduced until the condensate generation rate is less than the evaporation rate of the condensate by the flue gas. The magnitude of this gradual reduction in the minimum water passage area can be pre-configured: a larger reduction is configured when the total cold water flow rate is high, and a smaller reduction is configured when the total cold water flow rate is low. The reduction magnitude can also be dynamically adjusted; if the liquid level continues to rise after a single reduction of the minimum water passage area, subsequent reductions can be increased.

[0053] In this embodiment, after the water circuit switching component operates in the second mode and both the first and second water circuits are opened, if the condensate level rises, the minimum water passage area of ​​the second water circuit is reduced, so that the condensate generation rate is less than the evaporation rate of the condensate by the flue gas, ultimately keeping the condensate level within a safe range and reducing the risk of the condensate level rising and triggering a shutdown.

[0054] In another optional embodiment, the minimum flow area of ​​the second water passage can be directly adjusted to a preset minimum flow area to ensure that the water flow rate of the second water passage is adjusted to below 0.5 L / min. Figure 5 As shown in part (a), a first flow regulating valve 55 is provided in the first water circuit, and a second flow regulating valve 56 is provided in the second water circuit. The first flow regulating valve and the second flow regulating valve 56 can be water proportional valves or multi-position solenoid valves. The controller can adjust the water flow of the second water circuit to below 0.5L / min by controlling the second flow regulating valve 56.

[0055] It is understandable that the preset minimum water flow area can be measured experimentally. Under various water usage scenarios of gas water heaters, when the minimum water flow area of ​​the second water circuit is at the preset minimum water flow area, the water flow rate of the second water circuit is below 0.5L / min.

[0056] like Figure 5 As shown in section (b), a bypass pipe 57 is provided in the second water circuit in parallel with the second flow regulating valve 56. In the case of domestic water use, the water flow rate of the bypass pipe 57 will be less than 0.5L / min. The controller can directly control the second flow regulating valve 56 to close, that is, the minimum water passage area of ​​the second flow regulating valve 56 is 0, and there is water flow only in the bypass pipe 57 in the second water circuit.

[0057] In this embodiment, the water flow rate of the second water channel is limited to less than 0.5L / min. The water flow through the condenser heat exchanger is slow, and the heat exchange efficiency of the condenser heat exchanger is extremely low. This makes the rate of condensate generation less than the rate of evaporation of condensate by flue gas.

[0058] Example 3

[0059] Figure 6 This is a flowchart of a control method for a gas water heater provided in Embodiment 3 of the present invention. This embodiment of the present invention is an optimization based on Embodiment 1 described above, such as... Figure 6 As shown, the control method of this gas water heater includes:

[0060] S601. After the gas water heater is working, determine whether the atomizer is faulty.

[0061] In one embodiment, the atomizer is communicatively connected to the controller. The controller receives the current signal value fed back by the atomizer and determines whether the deviation between the current signal value and the preset current signal value is greater than a preset threshold. If yes, the atomizer is determined to be faulty, and S603-S605 are executed. If no, the atomizer is determined to be not faulty, and S602 is executed.

[0062] S602, The water circuit switching component is operated in the first mode. In the first mode, the first water circuit is closed and the second water circuit is open.

[0063] S603, The water circuit switching component is operated in the second mode, in which the first water circuit and the second water circuit are opened.

[0064] like Figure 3 Part (a) shows the state diagram of the first water path and the second water path in the first mode. The water path switching valve 51 can be a three-way valve, which can connect the main water inlet pipe 3, the first water path and the second water path. When the atomizer is not faulty, the controller 6 controls the three-way valve to open the second water path and close the first water path. The cold water flows into the main heat exchanger 1 only after passing through the condenser heat exchanger 2, and will not flow directly into the main heat exchanger 1 through the first water path. The cold water is completely heated by the condenser heat exchanger 2 before entering the main heat exchanger 1. The condenser heat exchanger 2 recovers the heat in the flue gas with high efficiency. Since the atomizer is not faulty and has sufficient atomization capacity, the condensate water is atomized and discharged into the atmosphere through the atomizer, which can effectively control the condensate water level within a safe range.

[0065] In an optional embodiment, when it is determined that the atomizer changes from a normal working state to a fault state, the water flow rate of the second water path is adjusted so that the condensate generation rate is less than the evaporation rate of the condensate by the flue gas. The condensate generation occurs when the high-temperature flue gas exchanges heat with the cold water in the heat exchange tube of the condenser heat exchanger, and the flue gas temperature reaches the dew point to condense and form condensate. The condensate evaporation occurs when the condensate is heated and evaporated under the high-temperature flue gas.

[0066] like Figure 3 As shown in section (b), the controller can control the water circuit switching valve 51, so that both the first and second water circuits are opened. A portion of the cold water in the main inlet pipe 3 flows into the main heat exchanger 1 after passing through the condenser heat exchanger 2, while a portion of the cold water flows directly into the main heat exchanger 1 through the first water circuit. Figure 3 In part (a), the amount of cold water flowing into the condenser heat exchanger 2 from the main water inlet pipe 3 is reduced, which reduces the rate of condensate generation in the condenser heat exchanger 2. At the same time, the condensate evaporates under the high temperature flue gas. When the rate of condensate generation is less than or equal to the rate of evaporation of condensate by the flue gas, it can ensure that the condensate level drops to a safe range. That is, by setting the second mode to deal with atomizer failure, it can ensure that the condensate level drops to a safe range. The gas water heater does not need to shut down the whole machine when the atomizer fails, so that users can use hot water normally.

[0067] S604. Obtain the real-time liquid level of condensate in the water collection chamber.

[0068] In one embodiment, such as Figure 7The schematic diagram shown illustrates the detection of liquid level using a liquid level probe. A liquid level gauge with a liquid level probe structure can be used to detect the real-time liquid level of condensate in the water collection chamber. The liquid level gauge with a liquid level probe structure includes a first liquid level probe 22, a second liquid level probe 23, and a common electrode 24 that extend into the water collection chamber 21. The distances from the ends of the second liquid level probe 23, the first liquid level probe 22, and the common electrode 24 extending into the water collection chamber 21 to the bottom of the water collection chamber 21 decrease sequentially. The first liquid level probe 22 and the second liquid level probe 23 are used to detect the first liquid level L1 and the second liquid level L2, respectively. The second liquid level L2 is higher than the first liquid level L1.

[0069] When the condensate water submerges the level probe, the condensate water acts as a conductive medium, causing the level probe and the common electrode 24 to form an electrical circuit. The level probe submerged in the condensate water outputs a level signal. That is, when the second level probe 23 outputs a level signal, the first level probe 22 also outputs a level signal synchronously. When the first level probe 22 does not output a level signal, the second level probe 23 also does not output a level signal. Based on the signal output status of each level probe, the real-time level height of the condensate water can be determined.

[0070] In another embodiment, such as Figure 8 The schematic diagram of the guide rod type float level device shown illustrates the real-time level detection of condensate in the water collection chamber. The device includes a guide rod 25 disposed within the water collection chamber 21, and a second signal triggering component 27 and a first signal triggering component 26 arranged sequentially from top to bottom on the guide rod 25. It also includes a float 28 that slides up and down the guide rod 25 as the liquid level rises and falls. When the float 28 floats up and down with the liquid level, passing the second signal triggering component 27 and the first signal triggering component 26, it outputs level signals indicating the second liquid level L2 and the first liquid level L1, respectively. Each level sensor can be an electromagnetic induction switch or a mechanical switch. The float 28 has a magnet or a triggering structure that triggers the mechanical switch. When the float 28 rises or falls with the liquid level, passing the level sensor, the corresponding level sensor outputs a level signal indicating the corresponding liquid level.

[0071] The above examples of liquid level probes and floats illustrate the principle of real-time liquid level detection of condensate in the water collection chamber. In practical applications, those skilled in the art can also use other methods to detect the real-time liquid level of condensate.

[0072] S605. Adjust the minimum water passage area of ​​the second water channel based on real-time liquid level.

[0073] For example, when the condensate level is high, the minimum water passage area of ​​the second water passage is small, and when the condensate level is low, the minimum water passage area of ​​the second water passage is large. This reduces the amount of condensate generated when the level is high and increases the amount of condensate generated when the level is low, thus keeping the condensate level within a safe range.

[0074] In one embodiment, the second water passage is equipped with a flow regulating valve, and the minimum water passage area of ​​the second water passage can be adjusted by adjusting the opening degree of the flow regulating valve.

[0075] In another embodiment, the second waterway includes multiple parallel waterway branches, each equipped with a switch valve. The minimum flow area of ​​the second waterway can be adjusted by controlling the switch valves of each waterway branch. It is understood that the minimum flow area of ​​the second waterway is the sum of the minimum flow areas of all the waterway branches.

[0076] In this embodiment, the first liquid level can be the liquid level that triggers the atomizer to start and enter the atomization working state. When the condensate liquid level is lower than the first liquid level, if the condensate liquid level continues to drop, it will cause the water collection chamber to deform and be damaged by the high temperature of the flue gas. The second liquid level can be the condensate backflow warning liquid level, and the second liquid level is lower than the trigger shutdown liquid level but higher than the first liquid level. That is to say, after the condensate liquid level rises to the second liquid level, if it continues to rise, there is a risk of backflow into the main heat exchanger. In severe cases, it will trigger the equipment shutdown protection. When the real-time liquid level is lower than the first liquid level, the minimum water passage area of ​​the second water path is increased to the first minimum water passage area. When the real-time liquid level is higher than the second liquid level, the minimum water passage area of ​​the second water path is reduced to the second minimum water passage area. The first minimum water passage area is greater than the second minimum water passage area. The first minimum water passage area and the second minimum water passage area can be pre-configured in the controller. The values ​​of the first minimum water passage area and the second minimum water passage area can be different for different models of gas water heaters.

[0077] In one embodiment, if such as Figure 7 The level gauge shown indicates that when the first level probe 22 does not output a signal, it means that the condensate is not submerged in the first level probe 22, and the real-time condensate level is lower than the first level L1. When the second level probe 23 outputs a signal, it means that the condensate has submerged the second level probe 23, and the real-time condensate level is higher than the second level L2. When the first level probe does not output a signal, and the real-time condensate level is lower than the first level L1, the minimum water passage area of ​​the second water path is adjusted to the first minimum water passage area. When the second level probe outputs a signal, and the real-time condensate level is higher than the second level L2, the minimum water passage area of ​​the second water path is adjusted to the second minimum water passage area, wherein the first minimum water passage area is larger than the second minimum water passage area.

[0078] It is understood that in this embodiment, both the first minimum water passage area and the second minimum water passage area are values ​​measured in advance through experiments. In various household water use scenarios, when the minimum water passage area of ​​the second water passage is adjusted to the first minimum water passage area, the real-time liquid level of the condensate will increase, that is, the condensate generation rate is greater than the evaporation rate of the condensate by the flue gas. In various household water use scenarios, when the minimum water passage area of ​​the second water passage is adjusted to the second minimum water passage area, the real-time liquid level of the condensate will decrease, that is, the condensate generation rate is less than the evaporation rate of the condensate by the flue gas.

[0079] In another embodiment, if such as Figure 8 The guide rod type float level device shown detects the real-time liquid level of condensate in the water collection chamber. The device includes a guide rod 25 disposed in the water collection chamber 21, and a second signal triggering component 27 and a first signal triggering component 26 disposed on the guide rod 25 at intervals from top to bottom. It also includes a float 28 that passes through the guide rod 25 and can slide up and down along the guide rod 25 as the liquid level rises and falls. When the float 28 floats up and down with the liquid level and passes the second signal triggering component 27 and the first signal triggering component 26, it outputs liquid level signals indicating the second liquid level L2 and the first liquid level L1, respectively. Each liquid level sensor can be an electromagnetic induction switch or a mechanical switch. The float 28 has a magnet or a triggering structure that triggers the mechanical switch. When the float 28 rises or falls with the liquid level and passes the liquid level sensor, the corresponding liquid level sensor outputs a liquid level signal indicating the corresponding liquid level. When the real-time liquid level is at the first liquid level L1, the minimum water flow area of ​​the second water path is adjusted to the first minimum water flow area; when the real-time liquid level is at the second liquid level L2, the minimum water flow area of ​​the second water path is adjusted to the second minimum water flow area; wherein, the first liquid level is lower than the second liquid level, and the first minimum water flow area is greater than the second minimum water flow area.

[0080] It is understood that in this embodiment, both the first minimum water passage area and the second minimum water passage area are values ​​measured in advance through experiments. In various household water use scenarios, when the minimum water passage area of ​​the second water passage is adjusted to the first minimum water passage area, the real-time liquid level of the condensate will increase, that is, the condensate generation rate is greater than the evaporation rate of the condensate by the flue gas. In various household water use scenarios, when the minimum water passage area of ​​the second water passage is adjusted to the second minimum water passage area, the real-time liquid level of the condensate will decrease, that is, the condensate generation rate is less than the evaporation rate of the condensate by the flue gas.

[0081] In the above embodiment three, after adjusting the minimum water passage area of ​​the second water path to ensure that the condensate generation rate is less than the evaporation rate of the condensate by the flue gas, and guaranteeing that the condensate level can drop, the real-time condensate level in the water collection chamber is obtained. When the real-time condensate level reaches the preset condition, the minimum water passage area of ​​the second water path is continuously adjusted by adjusting the real-time level to change the water flow rate in the second water path. This controls the condensate generation rate, thereby maintaining a dynamic balance between the overall condensate generation and evaporation. Even if the atomizer malfunctions, the condensate level can be controlled within a safe range, allowing the condensing heat exchanger to continue working to recover heat from the flue gas and generate condensate. This reduces the risk of the water collection chamber being damaged by heat in the high-temperature flue gas environment when the atomizer malfunctions and there is too much condensate triggering a shutdown, or when there is too little condensate. This improves the safety performance of the gas water heater.

[0082] Example 4

[0083] Figure 2 This is a schematic diagram of the structure of a gas water heater provided in Embodiment 4 of the present invention. Figure 2 As shown, the gas water heater includes a main heat exchanger 1, a condensing heat exchanger 2, a main inlet pipe 3, an atomizer 4, a water circuit switching component 5, and a controller 6. The water circuit switching component 5 is communicatively connected to the controller 6. The condensing heat exchanger 2 has a water collection chamber 21 for collecting the condensate produced by the condensing heat exchanger 2. The atomizer 4 is used to atomize the condensate. The water circuit switching component 5 includes a first water circuit and a second water circuit. The first water circuit is used to directly connect the main inlet pipe 3 to the main heat exchanger 1. The second water circuit is used to sequentially connect the main inlet pipe 3, the condensing heat exchanger 2, and the main heat exchanger 1. The controller is used to execute the control method of the gas water heater in any of the embodiments of Example 1 to Example 3.

[0084] like Figure 2 As shown, in an optional embodiment, the water circuit switching component 5 includes a first pipe 52, a second pipe 53, a third pipe 54, and a water circuit switching valve 51. The water circuit switching valve 51 is connected to the main water inlet pipe 3 and is communicatively connected to the controller 6. The first pipe 52 is connected to the inlet of the condensing heat exchanger 2 and the water circuit switching valve 51. The second pipe 53 is connected to the outlet of the condensing heat exchanger 2 and the inlet of the main heat exchanger 1. That is, the first pipe 52, the condensing heat exchanger 2, and the second pipe 53 are connected in sequence to form the second water circuit. The third pipe 54 is connected to the water circuit switching valve 51 and the inlet of the main heat exchanger 1 to form the first water circuit. The controller 6 can control the water circuit switching valve 51 to realize the closing and opening of the first water circuit and the second water circuit. The water circuit switching valve 51 can be one of a three-way valve, a multi-position solenoid valve, or a proportional valve.

[0085] Of course, gas water heaters can also include various types of level gauges, such as... Figure 5 The liquid level probe type liquid level gauge shown, such as Figure 6The guide rod type float level device is shown.

[0086] Controller 6 can be a variety of general-purpose and / or dedicated processing components with processing and computing capabilities. Some examples of controller 6 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any suitable processor, microcontroller, etc. Controller 6 performs the various methods and processes described above, such as the control methods for a gas water heater.

[0087] In some embodiments, the control method for the gas water heater may be implemented as a computer program tangibly contained in a computer-readable storage medium, which, when loaded and executed by the controller 6, can perform one or more steps of the control method for the gas water heater described above. Alternatively, in other embodiments, the controller 6 may be configured to perform the control method for the gas water heater by any other suitable means (e.g., by means of firmware).

[0088] In this embodiment, when the atomizer is functioning normally, the water circuit switching component operates in the first mode, closing the first water circuit and opening the second water circuit. The condenser heat exchanger operates with high thermal efficiency to recover heat from the flue gas, effectively improving the overall heat exchange efficiency of the gas water heater. When the atomizer malfunctions and cannot atomize the condensate, the water circuit switching component operates in the second mode, opening both the first and second water circuits. A portion of cold water is diverted through the first water circuit, reducing the amount of cold water flowing into the condenser heat exchanger. This slows down the condensate formation rate, resulting in a slower condensate level rise, or even no rise at all due to the evaporation of high-temperature flue gas. This prolongs the time it takes for the condensate level to reach the shutdown level, while the condenser heat exchanger continues to recover residual heat from the flue gas. Therefore, the gas water heater does not require rapid shutdown when the atomizer malfunctions, extending the user's normal hot water usage time and improving the user experience.

[0089] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this invention does not impose any limitations on them.

[0090] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A control method for a gas water heater, characterized in that, The gas water heater includes a main heat exchanger (1), a condenser heat exchanger (2), a main inlet pipe (3), an atomizer (4), and a water circuit switching assembly (5). The condenser heat exchanger (2) has a water collection chamber (21) for collecting the condensate produced by the condenser heat exchanger (2), and the atomizer (4) is used to atomize the condensate. The water circuit switching assembly (5) includes a first water circuit and a second water circuit. The first water circuit is used to directly connect the main inlet pipe (3) to the main heat exchanger (1), and the second water circuit is used to sequentially connect the main inlet pipe (3), the condenser heat exchanger (2), and the main heat exchanger (1). The control method includes: After the gas water heater has been operating, determine whether the atomizer is faulty; If not, control the water circuit switching component to operate in the first mode, in which the first water circuit is closed and the second water circuit is open; If so, the water circuit switching component is controlled to operate in the second mode, in which the first water circuit and the second water circuit are opened; The second water path is equipped with a flow regulating valve; the control method further includes: When it is determined that the atomizer changes from a normal working state to a fault state, the water flow rate of the second water circuit is adjusted so that the condensate generation rate is less than the evaporation rate of the condensate by the flue gas. Adjusting the water flow rate of the second water channel so that the rate of condensate generation is less than the rate of condensate evaporation from the flue gas includes: The real-time liquid level of the condensate is used to determine whether the liquid level of the condensate is rising. If so, reduce the minimum water passage area of ​​the second water channel so that the condensate generation rate is less than the evaporation rate of the condensate by the flue gas, and the condensate level decreases.

2. The control method according to claim 1, characterized in that, Determining whether the atomizer is faulty includes: Obtain the current signal value of the atomizer; Determine whether the deviation between the current signal value and the preset current signal value is greater than a preset threshold. If so, the atomizer is confirmed to be faulty; If not, it is determined that the atomizer is not faulty.

3. The control method according to claim 1, characterized in that, Reducing the minimum cross-sectional area of ​​the second waterway includes: The minimum water flow area of ​​the second water channel is gradually reduced until the rate of condensate generation is less than the rate of evaporation of condensate by flue gas, and the condensate level decreases.

4. The control method according to claim 1, characterized in that, Reducing the minimum cross-sectional area of ​​the second waterway includes: Adjust the minimum flow area of ​​the second water passage to the preset minimum flow area so that the water flow rate of the second water passage is adjusted to below 0.5L / min.

5. The control method according to claim 1, characterized in that, The gas water heater further includes a first liquid level probe and a second liquid level probe. The first liquid level probe is used to collect a first liquid level, and the second liquid level probe is used to collect a second liquid level. The first liquid level is lower than the second liquid level. After adjusting the water flow rate of the second water path so that the rate of condensate generation is less than the rate of condensate evaporation by flue gas, the control method further includes: Obtain the real-time liquid level of the condensate in the water collection chamber; When the first liquid level probe does not output a signal, it is determined that the real-time liquid level is lower than the first liquid level. The minimum water passage area of ​​the second water path is adjusted to the first minimum water passage area so that the condensate generation rate is greater than the evaporation rate of the condensate by the flue gas. When the second liquid level probe outputs a signal, it is determined that the real-time liquid level is higher than the second liquid level. The minimum water passage area of ​​the second water path is adjusted to the second minimum water passage area so that the condensate generation rate is less than the evaporation rate of the condensate by the flue gas. The first minimum water passage area is greater than the second minimum water passage area.

6. The control method according to claim 1, characterized in that, After adjusting the water flow rate of the second water channel so that the condensate generation rate is less than the evaporation rate of the condensate by the flue gas, the control method further includes: Obtain the real-time liquid level of the condensate in the water collection chamber; When the real-time liquid level is at the first liquid level, the minimum water passage area of ​​the second water passage is adjusted to the first minimum water passage area so that the condensate generation rate is greater than the evaporation rate of the condensate by the flue gas. When the real-time liquid level is at the second liquid level, the minimum water passage area of ​​the second water passage is adjusted to the second minimum water passage area so that the generation rate of the condensate is less than the evaporation rate of the condensate by the flue gas; wherein, the first liquid level is lower than the second liquid level, and the first minimum water passage area is greater than the second minimum water passage area.

7. The control method according to claim 6, characterized in that, The gas water heater also includes a guide rod type float level device for detecting the real-time liquid level. The guide rod type float level device includes a guide rod (25), a float (28) passing through the guide rod (25), and a first signal triggering component (26) and a second signal triggering component (27) located on the guide rod (25). The first signal triggering component (26) is at the same height as the first liquid level, and the second signal triggering component (27) is at the same height as the second liquid level.

8. A gas water heater, characterized in that, The device includes a main heat exchanger (1), a condenser heat exchanger (2), a main inlet pipe (3), an atomizer (4), a water circuit switching assembly (5), and a controller (6). The water circuit switching assembly (5) is communicatively connected to the controller (6). The condenser heat exchanger (2) has a water collection chamber (21) for collecting the condensate generated by the condenser heat exchanger (2). The atomizer (4) is used to atomize the condensate. The water circuit switching assembly (5) includes a first water circuit and a second water circuit. The first water circuit is used to directly connect the main inlet pipe (3) to the main heat exchanger (1). The second water circuit is used to sequentially connect the main inlet pipe (3), the condenser heat exchanger (2), and the main heat exchanger (1). The controller is used to execute the control method of the gas water heater according to any one of claims 1-7.

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