Gas-fired water heater and control method and control device therefor, and computer program

Abstract

The present application discloses a gas-fired water heater and a control method and control device therefor. The control method comprises the following steps: upon receiving an instruction for propagating a flame to a target combustion unit, obtaining a current fan speed and a current gas proportional valve secondary pressure; adjusting the current fan speed to a flame propagation fan speed FC, and adjusting the current gas proportional valve secondary pressure to a flame propagation secondary pressure CH; during adjustment of the gas proportional valve secondary pressure, maintaining a mapping relationship P=f(r) between the gas proportional valve secondary pressure and the fan speed, keeping the air-fuel ratio of the gas-fired water heater constant within a preset interval, and ensuring that the gas proportional valve secondary pressure at any moment during adjustment is larger than a secondary pressure flameout threshold CH'min corresponding to the fan speed at said moment; and controlling a target staging valve corresponding to the target combustion unit to be opened.

Description

Gas water heater and control method, control device and computer program thereof

[0001] Related applications

[0002] This application claims priority to Chinese patent application No. 202311436087.2 filed on October 31, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the technical field of gas water heaters, and in particular to a gas water heater and a control method and a control device thereof. Background Art

[0004] Currently, most gas water heaters (such as gas water heaters or wall-mounted boilers) use sectional burners. These burners consist of multiple combustion units, each of which consists of several burner chips arranged side by side. Segmented combustion is achieved by controlling the opening and closing of sectional valves corresponding to each combustion unit. This allows for both high-volume hot water needs at multiple points in winter and low-volume hot water needs at a single tap in summer.

[0005] However, in the process of segmented fire transmission of traditional gas water heaters, the secondary pressure of gas and the speed of fan often change suddenly, and the speed of change of the two is inconsistent, which easily leads to air-fuel ratio mismatch.

[0006] Summary of the Invention

[0007] The main purpose of this application is to propose a control method for a gas water heater, aiming to solve the problem of poor fire transmission during segmented combustion, improve the reliability of fire transmission, and thereby improve the quality reliability of the gas water heater.

[0008] To achieve the above objectives, the control method of the gas water heater proposed in this application includes the following steps:

[0009] When receiving the instruction to transmit fire to the target combustion unit, the current fan speed and the current secondary pressure of the gas proportional valve are obtained;

[0010] Adjust the current fan speed to the flame transfer fan speed FC and adjust the current gas proportional valve secondary pressure to the flame transfer secondary pressure CH; during the gas proportional valve secondary pressure adjustment process, control the mapping relationship between the gas proportional valve secondary pressure and the fan speed P = f(r), and keep the air-fuel ratio of the gas water heater constant in the preset range, ensuring that the gas proportional valve secondary pressure at any time during the adjustment process is greater than the secondary pressure flameout threshold CH' corresponding to the fan speed at the same time min ;

[0011] The target segmented valve corresponding to the target combustion unit is controlled to open, and the target combustion unit burns.

[0012] In one embodiment, the steps of adjusting the current fan speed to the flame transfer fan speed FC and adjusting the current gas proportional valve secondary pressure to the flame transfer secondary pressure CH include:

[0013] Under the condition that the time required for the secondary pressure of the gas proportional valve to decrease from the maximum secondary pressure PH to the minimum secondary pressure PL is the same as the time required for the fan speed to decrease from the maximum fan speed FH to the minimum fan speed FL, determine the fan speed change rate and the pressure change rate of the gas proportional valve secondary pressure;

[0014] According to the speed change rate and pressure change rate, the secondary pressure of the gas proportional valve is controlled to start adjusting at the same time as the fan speed, until the fan speed is adjusted to the flame transfer fan speed FC, and the secondary pressure of the gas proportional valve is adjusted to the flame transfer secondary pressure CH.

[0015] In one embodiment, the fire transmission secondary pressure CH is set to be greater than the secondary pressure CH' corresponding to the fire transmission fan speed FC according to the mapping relationship P=f(r).

[0016] In one embodiment, before the step of controlling the target segmented valve corresponding to the target combustion unit to open, the method further includes:

[0017] Get the moment when the fan speed starts to adjust;

[0018] The time when the target sectional valve is opened is determined based on the time when the fan speed starts to be adjusted and the preset time. The time when the target sectional valve is opened is delayed by the preset time compared to the time when the fan speed starts to be adjusted, and the time when the target sectional valve completes opening is no earlier than the time when the fan speed drops to the fire transfer fan speed FC.

[0019] In one embodiment, the step of controlling the opening of the target segmented valve corresponding to the target combustion unit is specifically as follows:

[0020] The target sectional valve is controlled to open when the fan speed drops to the fire transfer fan speed FC; or, the target sectional valve is controlled to open after the fan speed drops to the fire transfer fan speed FC.

[0021] In one embodiment, the flameout secondary pressure threshold CH' corresponding to the flameout fan speed FC min Less than the minimum secondary pressure of the fire transmission CH min , where the minimum secondary pressure of the fire transmission is CH min It is the minimum value of the secondary pressure drop during the instant when the target sectional valve is opened.

[0022] In one embodiment, the average value of the maximum secondary pressure PH and the minimum secondary pressure PL of the gas proportional valve is used as the reference secondary pressure P, and the value of the flame transfer secondary pressure CH is within the range of [P±10%].

[0023] In one embodiment, before the step of receiving the instruction to transmit fire to the target combustion unit, the method further includes:

[0024] Determine whether the current combustion unit can meet the hot water demand under the current working conditions;

[0025] If the hot water demand is not met, the fan speed under the current working conditions is adjusted to the maximum fan speed FH, and the secondary pressure of the gas proportional valve is adjusted to the maximum secondary pressure PH;

[0026] Determine whether the current combustion unit meets the hot water demand under the adjusted working conditions;

[0027] If the hot water demand is not met, a command to transfer fire to the target combustion unit is issued.

[0028] The present application also proposes a control device for a gas water heater, comprising:

[0029] A memory storing a control program of the gas water heater;

[0030] A processor is used to execute the control program of the gas water heater to implement the control method of the gas water heater as described above.

[0031] The present application also provides a gas water heater, wherein the gas water heater uses the control method of the gas water heater as described above;

[0032] Or include the control device of the gas water heater as described above.

[0033] The present application also proposes a computer program, which includes instructions. When the instructions are executed by a control device of a gas water heater, the control device of the gas water heater causes the control device of the gas water heater to execute the control method of the gas water heater as described above.

[0034] The technical solution of the present application controls the mapping relationship P = f(r) between the secondary pressure of the gas proportional valve and the fan speed during the adjustment process, and the air-fuel ratio of the gas water heater is constant within a preset range, ensuring that the secondary pressure of the gas proportional valve at any time during the adjustment process is greater than the secondary pressure flameout threshold CH' corresponding to the fan speed at the same time. min , thereby preventing the fan from blowing out the flame due to excessive speed, and avoiding the risk of flame transmission and flameout, thereby solving the problem of poor flame transmission during segmented combustion, improving flame transmission reliability, and thus improving the quality reliability of gas water heaters. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application 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 only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0036] FIG1 is a schematic structural diagram of an embodiment of a gas water heater of the present application;

[0037] FIG2 is a schematic diagram of the matching structure of the burner and the gas distribution rod in FIG1;

[0038] FIG3 is a schematic diagram of the matching structure of the burner and the gas distribution rod in FIG2 from another perspective;

[0039] FIG4 is a schematic diagram of fan speed, secondary pressure and sectional valve opening when the existing control method is used for fire transmission;

[0040] FIG5 is a schematic diagram of the fan speed, secondary pressure, and sectional valve opening when the existing control method is used for fire transmission (the secondary pressure fluctuates and decreases at the moment of valve opening);

[0041] FIG6 is a schematic diagram of fan speed, secondary pressure, and sectional valve opening when the control method according to an embodiment of the present application is used for fire transmission;

[0042] FIG7 is a schematic diagram of fan speed, secondary pressure, and sectional valve opening when a control method according to another embodiment of the present application is used for fire transmission;

[0043] FIG8 is a schematic diagram of fan speed, secondary pressure, and sectional valve opening during fire transmission using a control method according to another embodiment of the present application;

[0044] FIG9 is a flow chart of a control method for a gas water heater according to the first embodiment of the present application;

[0045] FIG10 is a flow chart of a control method for a gas water heater according to a second embodiment of the present application;

[0046] FIG11 is a flow chart of a control method for a gas water heater according to a third embodiment of the present application;

[0047] FIG12 is a flow chart of a control method for a gas water heater according to a fourth embodiment of the present application.

[0048] Description of Figure Numbers:

[0049] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0051] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0052] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0053] The inventors discovered that excessive fan speed can easily extinguish the flame, causing the gas water heater to restart, resulting in intermittent hot and cold water. After repeated flameouts, the gas water heater will report an unexpected flameout failure, requiring the user to restart the device before it can resume operation. Even after restarting, frequent flameout failures can persist, preventing normal operation and severely impacting the user experience. Consequently, flameouts and intermittent hot and cold water temperatures are a significant quality issue currently facing customer complaints regarding gas water heaters.

[0054] Please refer to Figure 1, which is a schematic structural diagram of a gas water heater 100 according to an embodiment of the present application. The gas water heater 100 includes but is not limited to a gas water heater or a wall-mounted boiler.

[0055] The gas water heater 100 includes a housing 10, and components disposed within the housing 10, including a hood 20, a heat exchanger 30, a burner 40, a gas proportional valve 50, a gas distribution rod 60, a fan 70, a water proportional valve 80, and a controller 90. The hood 20 is located on top of the heat exchanger 30, which is located on top of the burner 40. The fan 70 and gas distribution rod 60 are both located on the bottom of the burner 40. The housing 10 also includes an air inlet connector 11, a cold water inlet connector 12, a hot water outlet connector 13, and a power cord 14. Among them, the air inlet connector 11 is connected to the burner 40 via the gas proportional valve 50 and the gas distribution rod 60. The gas proportional valve 50 can be used to adjust the amount of gas delivered to the burner 40, and the gas distribution rod 60 can be used to distribute gas to the burner 40; the fan 70 is used to deliver air to the burner 40, and the amount of air delivered to the burner 40 can be adjusted by adjusting the speed of the fan 70; the cold water inlet connector 12 is connected to the water inlet pipe of the heat exchanger 30, and the water proportional valve 80 is arranged on the water inlet pipe, and the water outlet pipe of the heat exchanger 30 is connected to the hot water outlet connector 13. When the gas water heater 100 is operating, air and gas are mixed in a certain ratio within the burner 40 to form an air-fuel mixture. After the burner 40 is ignited, the air-fuel mixture burns within the combustion chamber of the burner 40 to produce high-temperature flue gas. The high-temperature flue gas exchanges heat with the heat exchanger 30, thereby heating the cold water delivered to the heat exchanger 30 via the cold water inlet connector 12 to form hot water. The hot water in the heat exchanger 30 is output via the hot water outlet connector 13 to meet the user's hot water needs. The specific operating principles of gas water heaters and wall-mounted boilers are well known to those skilled in the art and will not be described in detail here.

[0056] The burner 40 of the gas water heater 100 specifically relates to a segmented burner 40 capable of achieving segmented combustion. Specifically, the burner 40 includes at least two sections of combustion units, and each group of combustion units includes a number of burner monoliths arranged side by side. A gas distribution channel is provided in the gas distribution rod 60 corresponding to each group of combustion units, and the air inlet end of each gas distribution channel is provided with a segmented valve (specifically, a solenoid valve) for controlling the on-off of the air inlet, and the air outlet end of each gas distribution channel is provided with a nozzle that is the same in number and corresponds one to one with the gas monoliths of the corresponding combustion unit. The gas is ejected from the nozzle of the gas distribution rod 60, drawing in the surrounding air (i.e., primary air), entering the flow channel of the burner 40, and after mixing, it is ejected from the fire hole at the top of the burner 40. The tip of the ignition needle is placed above the fire hole of a burner monolith, igniting the air-fuel mixture ejected from the fire hole to form a flame, which is then transmitted to the other burner monoliths on both sides. The following mainly describes a burner 40 capable of achieving four-segmented combustion as an example.

[0057] As shown in Figures 2 and 3, in one embodiment, the burner 40 of the gas water heater 100 includes 18 burner monoliths arranged side by side. The 18 burner monoliths can be divided from left to right into 1-11 burner monoliths, 12-15 burner monoliths, and 16-18 burner monoliths. Among them, the 12-15 burner monoliths constitute the first combustion unit 41, the 16-18 burner monoliths constitute the second combustion unit 42, and the 1-11 burner monoliths constitute the third combustion unit 43. Correspondingly, a first gas distribution channel corresponding to the first combustion unit 41, a second gas distribution channel corresponding to the second combustion unit 42, and a third gas distribution channel corresponding to the third combustion unit 43 are provided in the gas distribution rod 60. A first segmentation valve 61 is provided at the air inlet end of the first gas distribution channel; a second segmentation valve 62 is provided at the air inlet end of the second gas distribution channel; and a third segmentation valve 63 is provided at the air inlet end of the third gas distribution channel. The outlet of the first gas distribution channel corresponds to the 12-15 burner chip, equipped with a 12-15 nozzle; the outlet of the second gas distribution channel corresponds to the 16-18 burner chip, equipped with a 16-18 nozzle; the outlet of the third gas distribution channel corresponds to the 1-11 burner chip, equipped with a 1-11 nozzle. An ignition needle is located above the first combustion unit 41 (i.e., the 12-15 burner chip).

[0058] When igniting, first open the first sectional valve 61, ignite the air-fuel mixture of 12-15 burner monolithic, realize that 12-15 totally 4 burner monolithic burns.When needs further increase combustion firepower, open the second sectional valve 62, the flame of the first combustion unit 41 is transferred to the second combustion unit 42 (also being 16-18 burner monolithic), realizes that 12-18 totally 7 burner monolithic burns.When needs further increase combustion firepower again, open the 3rd sectional valve 63, the flame of the first combustion unit 41 is transferred to the 3rd combustion unit 43 (also being 1-11 burner monolithic), then the first combustion unit 41 and the second combustion unit 42 go out, realize that 1-11 totally 11 burner monolithic burns.When the first sectional valve 61, the second sectional valve 62 and the 3rd sectional valve 63 all open, then can realize that 1-18 totally 18 burner monolithic burns. In this way, the burner 40 can realize 4-7-11-18 four-stage combustion.

[0059] The following is an analysis of the flame transfer process of the burner 40.

[0060] The controller 90 sets the maximum secondary pressure PH and the maximum fan speed FH of the gas proportional valve, and the air-fuel ratio of the two is matched; it also sets the secondary pressure CH and the fan speed FC of the fire transmission, and the air-fuel ratio of the two is matched. After ignition, the first segmented valve 61 opens, igniting the air-fuel mixture of the 12-15 burner slices, at which time the first combustion unit 41 performs combustion. When the secondary pressure is PH and the fan speed is FH, and the combustion of the first combustion unit 41 cannot meet the user's hot water demand, the second segmented valve 62 is opened, and the flame is transferred to the 16-18 burner slices, at which time the first combustion unit 41 and the second combustion unit 42 jointly perform combustion. When the secondary pressure is PH and the fan speed is FH, and the combustion of the first combustion unit 41 and the second combustion unit 42 still cannot meet the user's hot water demand, the third segmented valve 63 is opened, and the flame is transferred to the 1-11 burner slices, then the flame of the 12-18 burner slices is extinguished, and the third combustion unit 43 performs combustion. At this time, since the flames of the seven burner slices 12-18 will be extinguished, the risk of flameout in this fire transmission is the highest.

[0061] When the combined combustion of the first combustion unit 41 and the second combustion unit 42 (i.e., seven burner slices 12-18 in total) still cannot meet the user's hot water demand, it is necessary to transfer the fire to the third combustion unit 43 (i.e., 11 burner slices 1-11 in total) and use the third combustion unit 43 for combustion. As shown in FIG4 , the existing control program is to simultaneously (for example, at time t1) reduce the fan speed from the maximum fan speed FH to the fire transfer fan speed FC, reduce the gas proportional valve secondary pressure from the maximum secondary pressure PH to the fire transfer secondary pressure CH, and simultaneously open the third segment valve 63. However, due to inertia, the fan speed, the gas proportional valve secondary pressure, and the segment valve cannot achieve sudden changes, but require a period of time to change to the target value. The fan speed decreases over a period of ΔT1, and the gas proportional valve secondary pressure decreases over a period of ΔT2. ΔT1 = t2 - t1, and ΔT2 = t3 - t1. Due to the inherent properties of fan 70 and gas proportional valve 50, the gas secondary pressure rapidly decreases from the maximum secondary pressure PH to the flame secondary pressure CH when ΔT2 < ΔT1. However, the fan speed is still decreasing. The air-fuel ratio is mismatched, the fan speed is far higher than the required value, and it exceeds the flameout threshold, causing the flame to extinguish.

[0062] Furthermore, as shown in FIG5 , the existing control program opens the third sectional valve 63 at time t1, and the opening time of the third sectional valve 63 (ΔT3 = t4 - t1) is shorter than the time the secondary pressure drops, i.e., ΔT3 < ΔT2 << ΔT1. When the third sectional valve 63 opens, the first sectional valve 61 and the second sectional valve 62 remain open for a relatively short period of time. During this period of time, the three sectional valves remain open simultaneously, and the secondary pressure drops for a short period of time. This drop in secondary pressure further mismatches the air-fuel ratio, causing the fan speed to exceed the required speed value and exceed the flameout threshold, making the flame more likely to go out.

[0063] Based on the problem of poor fire transmission in traditional gas water heaters 100, this application proposes a control method for gas water heaters 100, which can solve the problem of poor fire transmission during segmented combustion, improve the reliability of fire transmission, and thus improve the quality reliability of the gas water heater 100.

[0064] Please refer to Figures 1 to 3. In one embodiment of the present application, the gas water heater 100 includes a burner 40, a gas proportional valve 50 and a fan 70. The gas proportional valve 50 is used to control the amount of gas entering the burner 40, and the fan 70 is used to control the amount of air entering the burner 40. The burner 40 includes at least two combustion units, and the air inlet end of each combustion unit is respectively provided with a sectional valve for controlling the on-off of the air inlet.

[0065] It should be noted that the gas water heater 100 includes but is not limited to a gas water heater or a wall-mounted boiler; wherein the gas water heater can be a strong drum type gas water heater with the fan 70 placed below, or a strong extraction type gas water heater with the fan 70 placed above. The burner 40 of the gas water heater 100 is a segmented burner, which can be specifically two-segment, three-segment, four-segment, etc. The following mainly takes the control method of a strong drum type gas water heater as shown in Figures 1 to 3 as an example to illustrate. Of course, the control method of the gas water heater 100 can also be applied to other types of gas water heaters and wall-mounted boilers, all within the scope of protection of this application. The specific structure of the strong drum type gas water heater shown in Figures 1 to 3 has been described in detail above and will not be repeated here.

[0066] Referring to FIG. 9 , in one embodiment of the present application, the control method of the gas water heater 100 includes the following steps:

[0067] S1. When receiving a command to transmit fire to a target combustion unit, the current fan speed and the current secondary pressure of the gas proportional valve are obtained.

[0068] Specifically, when the gas water heater receives an instruction to transfer fire to the target combustion unit, the current fan speed and the current gas proportional valve secondary pressure are obtained. It is understandable that when the current combustion unit is in the maximum firepower condition (that is, the condition of the highest fan speed and the maximum secondary pressure of the gas proportional valve) and the combustion still does not meet the user's hot water demand, it is necessary to transfer fire to the target combustion unit. That is, when executing the fire transfer instruction, the current fan speed is generally the highest fan speed or close to the highest fan speed, and the current gas proportional valve secondary pressure is generally the maximum secondary pressure of the gas proportional valve or close to the maximum secondary pressure of the gas proportional valve. Of course, in some cases, when the current combustion unit has not yet received the fire transfer instruction under the maximum firepower condition, the fire transfer step can also be executed.

[0069] S2. Adjust the current fan speed to the flame transfer fan speed FC and adjust the current gas proportional valve secondary pressure to the flame transfer secondary pressure CH. During the adjustment of the gas proportional valve secondary pressure, the mapping relationship between the gas proportional valve secondary pressure and the fan speed is controlled to maintain P = f(r). The air-fuel ratio of the gas water heater is constant within the preset range, ensuring that the gas proportional valve secondary pressure at any time during the adjustment process is greater than the secondary pressure flameout threshold CH' corresponding to the fan speed at the same time. min .

[0070] Specifically, taking the current fan speed as the maximum fan speed FH and the current gas proportional valve secondary pressure as the maximum secondary pressure PH as an example, the fan speed is adjusted from the maximum fan speed FH to the flame transfer fan speed FC, and the gas proportional valve secondary pressure is adjusted from the maximum secondary pressure PH to the flame transfer secondary pressure CH. The flame transfer fan speed FC and the flame transfer secondary pressure CH are preset values ​​pre-stored in the control program. During the gas proportional valve secondary pressure adjustment process (e.g., throughout the entire decrease in the gas proportional valve secondary pressure), the mapping relationship P = f(r) between the gas proportional valve secondary pressure and the fan speed is maintained. P represents the gas proportional valve secondary pressure, and f(r) is a function with the fan speed as a variable. This allows the gas proportional valve secondary pressure to change with changes in the fan speed. Since the gas proportional valve secondary pressure is related to the amount of gas delivered to the burner, and the fan speed is related to the amount of air delivered to the burner, the air-fuel ratio of the gas water heater remains constant within a preset range during the gas proportional valve secondary pressure adjustment process. This preset range can fluctuate around the optimal air-fuel ratio for achieving optimal combustion. That is, during the adjustment of the secondary pressure of the gas proportional valve, the air-fuel ratio of the gas water heater is always kept matched. In this way, it can be ensured that the secondary pressure of the gas proportional valve at any time during the adjustment process is greater than the secondary pressure flameout threshold CH' corresponding to the fan speed at the same time. min , thus preventing the fan from blowing out the flame due to excessive speed.

[0071] S3. Control the target sectional valve corresponding to the target combustion unit to open, and the target combustion unit burns.

[0072] Specifically, at the moment when the fan speed begins to be adjusted or thereafter, the target segmented valve is controlled to open. After the target segmented valve is opened, the gas distribution channel corresponding to the target combustion unit is opened, and gas can be delivered to the target combustion unit. The flame transmitted by the current combustion unit ignites the air-fuel mixture of the target combustion unit, and the target combustion unit burns; the fire transmission process is completed. After the fire transmission is completed, the current combustion unit can continue to burn, or the segmented valve corresponding to the current combustion unit can be closed, and the current combustion unit is extinguished. For example, as shown in Figure 3, the burner 40 includes a first combustion unit 41, a second combustion unit 42 and a third combustion unit 43. When the first combustion unit 41 and the second combustion unit 42 (i.e., seven burner monoliths, 12-18) burn together under the conditions of the highest fan speed FH and the maximum secondary pressure PH and still cannot meet the user's large hot water demand, it is necessary to transmit fire to the third combustion unit 43 (i.e., 11 burner monoliths, 1-11). At this time, the first combustion unit 41 and the second combustion unit 42 can be regarded as current combustion units, the third combustion unit 43 can be regarded as the target combustion unit, and the third section valve 63 corresponding to the third combustion unit 43 is the target section valve.

[0073] In the prior art, the fan speed and the gas proportional valve secondary pressure are adjusted independently, with no correlation between them. Due to the inherent properties of the fan 70 and gas proportional valve 50, the time required for the gas proportional valve secondary pressure to decrease from the maximum secondary pressure PH to the flame transfer secondary pressure CH is much shorter than the time required for the fan speed to decrease from the maximum fan speed FH to the flame transfer fan speed CH. When the gas proportional valve secondary pressure rapidly decreases to the flame transfer secondary pressure CH, while the fan speed is still decreasing, the air-fuel ratio is mismatched, the fan speed is far higher than the required speed value, and it exceeds the flameout threshold, causing the flame to extinguish.

[0074] The technical solution of the present application controls the mapping relationship P = f(r) between the secondary pressure of the gas proportional valve and the fan speed during the adjustment process, and the air-fuel ratio of the gas water heater is constant within a preset range, ensuring that the secondary pressure of the gas proportional valve at any time during the adjustment process is greater than the secondary pressure flameout threshold CH' corresponding to the fan speed at the same time. min , thereby preventing the fan from blowing out the flame due to excessive speed, and avoiding the risk of flame transmission and flameout, thereby solving the problem of poor flame transmission during segmented combustion, improving the reliability of flame transmission, and thus improving the quality reliability of the gas water heater 100.

[0075] Referring to FIG. 10 , in one embodiment, the steps of adjusting the current fan speed to the flame transfer fan speed FC and adjusting the current gas proportional valve secondary pressure to the flame transfer secondary pressure CH include:

[0076] S21. Determine the fan speed change rate and the gas proportional valve secondary pressure change rate when the time required for the gas proportional valve secondary pressure to decrease from the maximum secondary pressure PH to the minimum secondary pressure PL is the same as the time required for the fan speed to decrease from the maximum fan speed FH to the minimum fan speed FL.

[0077] S22. Control the secondary pressure of the gas proportional valve and the fan speed to start adjusting at the same time according to the speed change rate and the pressure change rate, until the fan speed is adjusted to the flame transfer fan speed FC and the secondary pressure of the gas proportional valve is adjusted to the flame transfer secondary pressure CH.

[0078] Specifically, during the development process, the maximum fan speed FH and minimum speed FL, as well as the maximum secondary pressure PH and minimum secondary pressure PL of the gas proportional valve, were pre-set. The air-fuel ratios of the maximum speed FH and the maximum secondary pressure PH were matched, and the air-fuel ratios of the minimum speed FL and the minimum secondary pressure PL were matched. As shown in Figure 8, it takes time ΔT = t3 - t1 for the fan to decrease from the maximum speed FH to the minimum speed FL. The rate of decrease of the gas proportional valve secondary pressure can be programmed to reduce the time required to decrease from the maximum secondary pressure PH to the minimum secondary pressure PL by ΔT = t3 - t1. This allows the gas water heater to maintain a constant air-fuel ratio within the preset range during the decrease of the gas proportional valve secondary pressure, and the fan speed and secondary pressure always maintain a matching air-fuel ratio.

[0079] Furthermore, the flame transfer secondary pressure CH is set to be greater than the secondary pressure CH' corresponding to the flame transfer fan speed FC according to the mapping relationship P = f(r). As shown in Figure 8, when the secondary pressure drops from the maximum secondary pressure PH to the flame transfer secondary pressure CH, the secondary pressure remains at the flame transfer secondary pressure CH and does not decrease further. However, the fan speed continues to decrease. When the fan speed approaches the flame transfer fan speed FC, the secondary pressure CH' corresponding to the flame transfer fan speed FC according to the mapping relationship P = f(r) is less than the flame transfer secondary pressure CH. In other words, after the secondary pressure drops to the flame transfer secondary pressure CH, while the fan speed continues to decrease, the secondary pressure of the gas proportional valve is relatively high, preventing flameout due to excessive fan speed, further improving flame transfer stability.

[0080] As shown in FIG11 , in one embodiment, before the step of controlling the target segmented valve corresponding to the target combustion unit to open, the method further includes:

[0081] S301, obtaining the time when the fan speed starts to be adjusted;

[0082] S302. Determine the time to control the target sectional valve to open based on the time when the fan speed starts to be adjusted and the preset time. The time to control the target sectional valve to open is delayed by the preset time compared to the time when the fan speed starts to be adjusted, and the time when the target sectional valve completes opening is no earlier than the time when the fan speed drops to the fire transfer fan speed FC.

[0083] In this embodiment, the moment when the target sectional valve is controlled to open is delayed by a preset time period compared to the moment when the fan speed starts to be adjusted, so that the target sectional valve is opened when the fan speed drops to the fire transfer fan speed FC or later, thereby reducing the risk of the flame being blown out due to the secondary pressure drop generated at the moment of valve opening and the fan speed being too high.

[0084] For example, as shown in FIG6 , in one embodiment, the fan speed begins to adjust from the maximum fan speed FH at time t1, and the fan speed drops to the flame transfer fan speed FC at time t2. At time t4, after time t1 and before time t2 (i.e., t1 < t4 < t2), the target sectionalizing valve (e.g., the third sectionalizing valve 63) is controlled to open, so that the target sectionalizing valve completes opening at time t2, i.e., the time of valve completion coincides with the time when the fan speed drops to the flame transfer fan speed FC. For another example, as shown in FIG7 , in another embodiment, the target sectionalizing valve (e.g., the third sectionalizing valve 63) may be controlled to open at time t5, after time t4 (i.e., t5 > t4), so that the target sectionalizing valve completes opening at time t6 (i.e., t6 > t2), i.e., the time when the target sectionalizing valve completes opening is later than the time when the fan speed drops to the flame transfer fan speed FC. After the fan speed drops to the flame transfer fan speed FC, the fan speed remains constant. Even if the secondary pressure of the gas proportional valve fluctuates from falling to rising, the flameout will not occur as long as it is not lower than the secondary pressure threshold of flameout.

[0085] In one embodiment, the step of controlling the opening of the target segmented valve corresponding to the target combustion unit is specifically as follows:

[0086] The target sectional valve is controlled to open when the fan speed drops to the fire transfer fan speed FC; or, the target sectional valve is controlled to open after the fan speed drops to the fire transfer fan speed FC.

[0087] In this embodiment, opening the target sectional valve at or after the fan speed drops to the flame transfer fan speed FC ensures that the target sectional valve completes opening after the fan speed drops to the flame transfer fan speed FC. This reduces the risk of flame extinguishment due to excessive fan speed caused by a secondary pressure drop at the moment of valve opening.

[0088] In order to further eliminate the risk of flameout due to the secondary pressure drop at the moment of valve opening, in one embodiment, the flameout secondary pressure threshold CH' corresponding to the flame fan speed FC is min Less than the minimum secondary pressure of the fire transmission CH min , where the minimum secondary pressure of the fire transmission is CH min It is the minimum value of the secondary pressure drop during the instant when the target sectional valve is opened.

[0089] Specifically, the flameout secondary pressure threshold and the flameout fan speed can be pre-set during the development process. The setting method is to measure the minimum value of the flameout secondary pressure drop at the moment the target segment valve opens and take it as the flameout secondary pressure minimum CH. min ; Set the flame transmission fan speed FC, and ensure that the flameout secondary pressure threshold CH' corresponding to the flame transmission fan speed FC min Less than the minimum secondary pressure of the fire transmission CH min In this way, since the target sectional valve is completed to open at the time not earlier than the time when the fan speed drops to the flame transmission fan speed FC, at the time when the target sectional valve is completed to open, the fan speed is kept at a constant flame transmission fan speed FC. Even if the secondary pressure of the gas proportional valve fluctuates downward and then upward, as long as the flame transmission secondary pressure reaches the minimum value CH min Not less than the flameout secondary pressure threshold CH' corresponding to the flameout fan speed FC min , there will be no flameout, thereby eliminating the risk of flameout caused by the secondary pressure drop at the moment of valve opening, thereby further improving the flame transmission reliability and further improving the quality reliability of the gas water heater 100.

[0090] In one embodiment, the average of the maximum secondary pressure PH and the minimum secondary pressure PL of the gas proportional valve is used as the reference secondary pressure P, and the ignition secondary pressure CH is set within the range of [P ± 10%]. Specifically, P = (PH + PL) / 2. The ignition secondary pressure CH is set within the range of [P ± 10%]. After ignition is completed, the difference between the gas proportional valve secondary pressure rising to the maximum secondary pressure PH and falling to the minimum secondary pressure PL is substantially the same.

[0091] Based on the above embodiment, as shown in FIG12 , in one embodiment, before the step of receiving the instruction to transmit fire to the target combustion unit, the step further includes:

[0092] S01. Determine whether the current combustion unit meets the hot water demand under the current working conditions;

[0093] S02. If the hot water demand is not met, the fan speed under the current working condition is adjusted to the maximum fan speed FH, and the secondary pressure of the gas proportional valve is adjusted to the maximum secondary pressure PH;

[0094] S03, determining whether the current combustion unit combustion under the adjusted working conditions meets the hot water demand;

[0095] S04. If the hot water demand is not met, a command to transmit fire to the target combustion unit is issued.

[0096] Specifically, after the gas water heater 100 is turned on, a lower firepower level can be used for heating. For example, as shown in Figures 2 and 3, during ignition, the first segmented valve 61 is first opened to ignite the air-fuel mixture of the 12-15 burner segments, allowing the first combustion unit 41 (12-15, a total of four burner segments) to burn. Under this operating condition, the corresponding fan speed can be between the maximum fan speed FH and the minimum low fan speed FL, and the corresponding gas proportional valve secondary pressure under this operating condition can be between the maximum secondary pressure PH and the minimum secondary pressure PL, as long as the air-fuel ratio is matched. The outlet water temperature can be detected by a temperature sensor and compared with the target hot water temperature set by the user. When the detected outlet water temperature does not reach the target hot water temperature, it indicates that the current combustion unit (e.g., the first combustion unit 41) is not meeting the heat demand under the current operating condition. When the hot water demand is not met, the firepower level can be increased by adjusting the fan speed to the maximum fan speed FH and the gas proportional valve secondary pressure to the maximum secondary pressure PH. It should be noted that if, in the initial state, the current combustion unit is already burning under the conditions of the highest fan speed FH and the maximum secondary pressure PH, steps S02 and S03 can be omitted.

[0097] It is determined whether the combustion of the current combustion unit (for example, the first combustion unit 41) meets the hot water demand under the conditions of the maximum fan speed FH and the maximum secondary pressure PH; if the hot water demand is not met, the controller 90 issues an instruction to transfer fire to the target combustion unit (for example, the second combustion unit 42); then the fire can be transferred in accordance with the method of delaying the adjustment of the secondary pressure and / or delaying the opening of the valve in the aforementioned embodiment, thereby realizing the combustion of the first combustion unit 41 and the second combustion unit 42 (12-18, a total of 7 burner single pieces). Continue to judge whether the combustion of the current combustion unit (for example, the first combustion unit 41 and the second combustion unit 42) meets the hot water demand under the conditions of the highest fan speed FH and the maximum secondary pressure PH; if the hot water demand is still not met, the controller 90 issues an instruction to transfer the fire to the next target combustion unit (for example, the third combustion unit 43); then the fire can be transferred in accordance with the method of delaying the adjustment of the secondary pressure and / or delaying the opening of the valve in the aforementioned embodiment, and after the fire transfer is stable, close the first segmented valve 61 and the second segmented valve 62, so as to realize the combustion of the third combustion unit 43 (1-11, a total of 11 burner single pieces). In this way, by performing combustion in a segmented fire transfer manner, the different fire power levels of the burner 40 can be adjusted, thereby meeting the different hot water needs of users, and the fire transfer performance is reliable, which can improve the quality reliability of the gas water heater 100.

[0098] It should be noted that the above description is of specific embodiments of this specification. Other embodiments are within the scope of the appended claims. Unless otherwise specified, the above steps S1, S2, and S3 are not limited to a sequential order. In some cases, the actions or steps described in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0099] The present application also proposes a control device for a gas water heater 100, comprising:

[0100] A memory storing a control program of the gas water heater;

[0101] A processor is used to execute the control program of the gas water heater to implement the control method of the gas water heater 100 as described in any of the above embodiments.

[0102] Specifically, when the control program of the gas water heater stored in the memory is executed by the processor, at least the control method of the gas water heater 100 of any one of the above-mentioned embodiments is implemented. It can be understood that since the control device of the gas water heater 100 of the present application implements the control method of the gas water heater 100 of any one of the above-mentioned embodiments, the embodiment of the control device of the gas water heater 100 of the present application includes all the technical solutions of all the embodiments of the control method of the above-mentioned gas water heater 100, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0103] In addition, the present application also provides a gas water heater 100, which utilizes the control method for a gas water heater 100 described in any of the aforementioned embodiments or includes the control device for a gas water heater 100 described in any of the aforementioned embodiments. It is understood that since the present application utilizes the control method or control device for a gas water heater 100 described in any of the aforementioned embodiments on the gas water heater 100, the embodiments of the gas water heater 100 described in the present application include all technical solutions of all embodiments of the control method or control device for the gas water heater 100 described above, and the technical effects achieved are identical, which will not be further elaborated here. The gas water heater 100 includes, but is not limited to, a gas water heater or a wall-mounted boiler; the gas water heater can be a forced-drum gas water heater with a fan 70 positioned below, or a forced-draft gas water heater with a fan 70 positioned above. The burner 40 of the gas water heater 100 is a segmented burner, which can be two-segment, three-segment, four-segment, etc., without specific limitation herein.

[0104] The above description is merely an embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structural transformation made by using the contents of the present application specification and drawings under the application concept of the present application, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. A method for controlling a gas water heater, wherein: The control method comprises the following steps: When receiving the instruction to transmit fire to the target combustion unit, the current fan speed and the current secondary pressure of the gas proportional valve are obtained; Adjust the current fan speed to the flame transfer fan speed FC and adjust the current gas proportional valve secondary pressure to the flame transfer secondary pressure CH; during the adjustment of the gas proportional valve secondary pressure, control the mapping relationship between the gas proportional valve secondary pressure and the fan speed P = f (r), and keep the air-fuel ratio of the gas water heater constant in the preset range, ensuring that the gas proportional valve secondary pressure at any time during the adjustment process is greater than the secondary pressure flameout threshold CH' corresponding to the fan speed at the same time min ; The target segmented valve corresponding to the target combustion unit is controlled to open, and the target combustion unit burns.

2. The control method of the gas water heater according to claim 1, wherein: The steps of adjusting the current fan speed to the flame transfer fan speed FC and adjusting the current gas proportional valve secondary pressure to the flame transfer secondary pressure CH include: Under the condition that the time required for the secondary pressure of the gas proportional valve to decrease from the maximum secondary pressure PH to the minimum secondary pressure PL is the same as the time required for the fan speed to decrease from the maximum fan speed FH to the minimum fan speed FL, determine the speed change rate of the fan and the pressure change rate of the secondary pressure of the gas proportional valve; The secondary pressure of the gas proportional valve is controlled according to the speed change rate and the pressure change rate to start adjusting at the same time as the fan speed, until the fan speed is adjusted to the flame transfer fan speed FC, and the secondary pressure of the gas proportional valve is adjusted to the flame transfer secondary pressure CH.

3. The control method of the gas water heater according to claim 1 or 2, wherein: The fire transmission secondary pressure CH is set to be greater than the secondary pressure CH' corresponding to the fire transmission fan speed FC according to the mapping relationship P=f(r).

4. The control method of the gas water heater according to any one of claims 1 to 3, wherein: Before the step of controlling the target segmented valve corresponding to the target combustion unit to open, the control method further includes: Get the moment when the fan speed starts to be adjusted; The time for controlling the target sectional valve to open is determined based on the time when the fan speed starts to be adjusted and the preset time. The time for controlling the target sectional valve to open is delayed by the preset time compared with the time when the fan speed starts to be adjusted, and the time when the target sectional valve completes opening is no earlier than the time when the fan speed drops to the fire transmission fan speed FC.

5. The control method of the gas water heater according to any one of claims 1 to 4, wherein: The step of controlling the target segmented valve corresponding to the target combustion unit to open comprises: The target sectional valve is controlled to open when the fan speed drops to the fire transfer fan speed FC; or, the target sectional valve is controlled to open after the fan speed drops to the fire transfer fan speed FC.

6. The control method of the gas water heater according to any one of claims 1 to 5, wherein: The flameout secondary pressure threshold CH' corresponding to the flame transmission fan speed FC min Less than the minimum secondary pressure of the fire transmission CH min , where the minimum secondary pressure of the fire transmission is CH min It is the minimum value of the secondary pressure drop when the target sectional valve is opened.

7. The control method of the gas water heater according to any one of claims 1 to 6, wherein: The average value of the maximum secondary pressure PH and the minimum secondary pressure PL of the gas proportional valve is taken as the reference secondary pressure P, and the value of the flame transmission secondary pressure CH is within the range of [P±10%].

8. The control method of the gas water heater according to any one of claims 1 to 7, wherein: Before the step of receiving the instruction to transmit fire to the target combustion unit, the control method further includes: It is determined that the combustion of the current combustion unit under the current working condition does not meet the hot water demand, the fan speed under the current working condition is adjusted to the maximum fan speed FH, and the secondary pressure of the gas proportional valve is adjusted to the maximum secondary pressure PH.

9. The control method of the gas water heater according to claim 8, wherein: The control method further comprises: It is determined that the combustion of the current combustion unit under the adjusted working conditions does not meet the hot water demand, and a command to transmit fire to the target combustion unit is issued.

10. A control device for a gas water heater, wherein: The control device comprises: A memory, wherein the memory stores a control program of the gas water heater; A processor, wherein the processor is used to execute a control program of the gas water heater to implement a control method of the gas water heater as described in any one of claims 1 to 9.

11. A gas water heater, wherein: The gas water heater uses the control method of the gas water heater according to any one of claims 1 to 9; Or it includes the control device of the gas water heater as claimed in claim 10.

12. A computer program, wherein: The computer program includes instructions, and when the instructions are executed by the control device of the gas water heater, the control device of the gas water heater executes the control method of the gas water heater according to any one of claims 1 to 9.

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