Gas water heater control method and device and gas water heater

Abstract

This invention provides a gas water heater control method, device, and gas water heater, relating to the field of water heater technology. The method includes: acquiring a flame state signal of the burner detected by a flame detection device; determining the flame detachment state of the burner based on the flame state signal; and reducing the fan speed when the burner is determined to be in a flame detachment state, so that the burner is in a normal combustion state. This invention acquires the flame state signal through a flame detection device, enabling rapid detection of whether flame detachment has occurred in the burner, thereby promptly reducing the fan speed to weaken airflow disturbance and restore normal flame combustion. This significantly shortens the delay time from flame detachment to fan speed adjustment response, effectively solving the problem of localized flame detachment or even flameout under low load operation or low gas pressure conditions, and significantly improving the combustion stability of the gas water heater.

Description

Technical Field

[0001] This invention relates to the field of water heater technology, and in particular to a gas water heater control method, device, and gas water heater. Background Technology

[0002] Gas water heaters, a common household water heating device, work by using a fan to draw air into the combustion chamber, where it mixes with gas and is ignited, thereby heating the water flowing through the heat exchanger. To ensure complete combustion and prevent backflow of flue gas, a certain air pressure is usually required from the fan.

[0003] In practical use, the velocity distribution of gas ejected from the burner assembly's exhaust ports is usually uneven. This velocity difference can lead to localized flame detachment or even flameout in low-load operation scenarios (such as summer when the inlet water temperature is high and only a small amount of heating is needed) and high fan speeds. In areas with higher velocity, the flame is easily blown away from the burner ports by the high-speed airflow, resulting in flame detachment, and in severe cases, it may even extinguish completely. Meanwhile, the flame in areas with lower velocity can still maintain normal combustion. Especially during peak gas consumption periods in residential areas, the pre-gas pressure at the user's end may drop significantly (e.g., to around 500 Pa). Under low gas pressure conditions, the flame itself is less resistant to wind, and the localized flame detachment problem caused by uneven velocity becomes more pronounced, easily affecting the normal combustion of the water heater and the normal output of the heat load. Summary of the Invention

[0004] The first technical problem solved by this invention is to provide a gas water heater control method that can effectively alleviate the problem of local flame detachment or even flameout in gas water heaters.

[0005] The second technical problem solved by this invention is to provide a gas water heater control device that can effectively alleviate the problem of partial flame detachment or even flameout in gas water heaters.

[0006] The third technical problem solved by this invention is to provide a gas water heater that can effectively alleviate the problem of local flame detachment or even flameout in gas water heaters.

[0007] The first technical problem mentioned above is solved by the following technical solution: A gas water heater control method is disclosed. The gas water heater includes a burner, a flame detection element, a fan, and a main controller. The flame detection element is disposed in the flame combustion area above the burner. The main controller is connected to both the flame detection element and the fan. The gas water heater control method is applied to the main controller and includes: acquiring a flame status signal of the burner detected by the flame detection element; determining the flame lift-off state of the burner based on the flame status signal; and reducing the fan speed when the burner is determined to be in a flame lift-off state, so that the burner is in a normal combustion state.

[0008] Compared with the prior art, the gas water heater control method of the present invention has the following advantages: by acquiring flame status signals through a flame detection device, it can quickly detect whether flame detachment has occurred in the burner, thereby timely reducing the fan speed to weaken airflow disturbance and allow the flame to resume normal combustion. This significantly shortens the delay time from flame detachment to fan speed adjustment response, effectively solving the problem of local flame detachment or even flameout under low load operation or low gas pressure conditions, and significantly improving the combustion stability of the gas water heater.

[0009] In one embodiment, the flame detection element includes a first detection element disposed in the flame stabilization region of the flame bar and a second detection element disposed in the flame departure region of the flame bar; the flame departure state determination of the flame bar based on the flame state signal includes: determining the flame departure state of the flame bar based on a first signal detected by the first detection element and a second signal detected by the second detection element.

[0010] In one embodiment, the first detection element is a main feedback needle, and the second detection element is a flame detachment feedback needle. The main feedback needle is located in the flame stabilization region above the burner, and the flame detachment feedback needle is located in the flame detachment region above the burner. The first signal includes a first sampled value detected by the main feedback needle, and the second signal includes a second sampled value detected by the flame detachment feedback needle.

[0011] In one embodiment, the flame stable region is the region where the flame burns normally under the set operating conditions, and the flame-off region is the region where flame-off occurs under the set operating conditions; wherein, the set operating conditions are the conditions in which the fan operates at the standard speed corresponding to the demand load, and the gas front pressure is adjusted to the set pressure value, and the set pressure value ranges from 400 Pa to 700 Pa.

[0012] In one embodiment, the flame lift-off state of the burner is determined based on a first signal detected by a first detector and a second signal detected by a second detector, including: when the first signal is less than or equal to a preset first threshold and the second signal is greater than or equal to a preset second threshold, the burner is determined to be in a flame lift-off state; wherein the second threshold is greater than the first threshold.

[0013] In one embodiment, the determination of the flame lift-off state of the burner based on the first signal detected by the first detector and the second signal detected by the second detector further includes: determining that the burner is in a normal combustion state when the first signal is less than or equal to a first threshold and the second signal is less than or equal to the first threshold; and determining that the burner is still in the state of the previous determination when the first signal is less than or equal to the first threshold and the second signal is greater than the first threshold and less than the second threshold.

[0014] In one embodiment, reducing the fan speed includes: controlling the fan speed to decrease by a first preset speed; wherein, after each decrease of the first preset speed, it is re-determined whether the burner is still in the flame-off state; if so, the first preset speed is decreased again until the burner is in normal combustion state or the fan speed drops to a preset minimum allowable speed.

[0015] In one embodiment, the gas water heater control method further includes: when the fan speed drops to the minimum allowable speed, and it is still determined that the burner is in a flame-off state, determining that the flame detection element has malfunctioned, and providing fault feedback.

[0016] In one embodiment, after determining that the burner is in a flame-off state and reducing the fan speed, and after determining that the burner is in a normal combustion state, the gas water heater control method further includes: obtaining the current heat load value; when the current heat load value is greater than or equal to the heat load threshold, restoring the fan speed; wherein the heat load threshold is determined based on the reference heat load value when the burner is in a normal combustion state before the fan speed is reduced due to flame-off.

[0017] In one embodiment, the gas water heater control method further includes: when it is determined that the burner is in normal combustion state and the fan speed reaches the standard speed corresponding to the demand load, the currently calculated heat load value is used as the reference heat load value.

[0018] In one embodiment, the heat load threshold is the product of a reference heat load value and a preset load correction factor; wherein the load correction factor is less than 1.

[0019] In one embodiment, restoring the fan speed includes: controlling the fan speed to increase a second preset speed sequentially; wherein, after each increase of the second preset speed, it is re-determined whether the burner is still in normal combustion state and whether the current heat load value is still greater than or equal to the heat load threshold; if so, the second preset speed is increased again until the fan speed reaches the standard speed corresponding to the required load.

[0020] The second technical problem mentioned above is solved by the following technical solution: A gas water heater control device is provided. The gas water heater includes a burner, a flame detection element, a fan, and a main controller. The flame detection element is disposed in the flame combustion area above the burner. The main controller is connected to both the flame detection element and the fan. The gas water heater control device is applied to the main controller and includes: The signal acquisition module is used to acquire the flame status signal of the flame detector detected by the flame detector. The flame lift-off detection module is used to determine the flame lift-off status of the firebox based on the flame status signal. The speed control module is used to reduce the fan speed when it is determined that the burner is in a flame-off state, so that the burner is in a normal combustion state.

[0021] Compared with the prior art, the gas water heater control device of the present invention has the following advantages: by acquiring flame status signals through a flame detection element, it can quickly detect whether flame detachment has occurred in the burner, thereby promptly reducing the fan speed to weaken airflow disturbance and allow the flame to return to normal combustion. This significantly shortens the delay time from flame detachment to fan speed adjustment response, effectively solving the problem of localized flame detachment or even flameout under low load operation or low gas pressure conditions, and significantly improving the combustion stability of the gas water heater.

[0022] The third technical problem mentioned above is solved by the following technical solution: A gas water heater includes a burner, a flame detection element, a fan, and a main controller. The flame detection element is disposed in the flame combustion area above the burner, and the main controller is connected to both the flame detection element and the fan. The main controller is used to execute the above-described gas water heater control method.

[0023] Compared with the prior art, the gas water heater of the present invention has the following advantages: by acquiring flame status signals through a flame detection device, it can quickly detect whether flame detachment has occurred in the burner, thereby promptly reducing the fan speed to weaken airflow disturbance and allow the flame to resume normal combustion. This significantly shortens the delay time from flame detachment to fan speed adjustment response, effectively solving the problem of localized flame detachment or even flameout under low load operation or low gas pressure conditions, and significantly improving the combustion stability of the gas water heater. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 A flowchart of a gas water heater control method provided in this application embodiment; Figure 2 A flowchart of another gas water heater control method provided in the embodiments of this application; Figure 3 This application provides a schematic diagram of the overall structure of a gas water heater according to an embodiment of the present application. Figure 4 A schematic diagram illustrating the connection between the main controller and the feedback pin on the burner assembly, provided in an embodiment of this application; Figure 5A control logic flowchart of a gas water heater control method provided in this application embodiment; Figure 6 This is a schematic diagram of the structure of a gas water heater control device provided in an embodiment of this application. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0028] Example 1: In this embodiment, the gas water heater includes a burner, a flame detection element, a fan, and a main controller. The flame detection element is located in the flame combustion area above the burner, and the main controller is connected to both the flame detection element and the fan. This embodiment also provides a gas water heater control method, which is applied to the main controller. See also... Figure 1 The flowchart shown is a method for controlling a gas water heater. The method mainly includes the following steps S102 to S106: Step S102: Obtain the flame status signal of the flame detector detected by the flame detector.

[0029] In this embodiment, the flame detection device can be a sensor used to sense the physical characteristics of a flame, and its function is to convert the combustion state of the flame into an electrical signal that can be recognized by the main controller. Optionally, the flame detection device can be one of an ion sensing needle, an ultraviolet phototube, or an infrared flame sensor. The flame state signal can be an analog or digital signal reflecting the presence, intensity, or attachment location of the flame, such as an ion current value or an AD (Analog-to-Digital Conversion) sample value.

[0030] In one possible implementation, the main controller can periodically read the voltage or current signal output by the flame detector through an analog-to-digital converter interface and convert it into AD sampling values ​​to obtain the flame status signal.

[0031] Step S104: Determine the flameout status of the firebox based on the flame status signal.

[0032] In this embodiment, the flame-detached state refers to an unstable state in which the flame root detaches from the surface of the flame hole and hangs at a certain distance above the flame hole; the flame in the flame-detached state is easily extinguished by airflow disturbance.

[0033] In one possible implementation, the flame detection device may include a first detection device located in the flame stabilization region of the fire bar and a second detection device located in the flame lift-off region of the fire bar. The flame lift-off state of the fire bar can be determined based on a first signal detected by the first detection device and a second signal detected by the second detection device.

[0034] Specifically, the stable flame zone is the area above the burner hole where the flame burns stably, while the flame-detachment zone is the area above the burner hole where the flame is prone to detachment. Based on the signals detected in these two zones, it can be accurately determined whether the firebox is in a flame-detachment state: when the first signal indicates the presence of a flame, and the second signal indicates the absence of a flame, the firebox is in a flame-detachment state; when both the first and second signals indicate the presence of a flame, the firebox is in a normal combustion state. Furthermore, when the first signal indicates the absence of a flame, it indicates that the firebox is in a extinguished state. Normal combustion refers to a state where the flame root is tightly attached to the surface of the burner hole, and combustion is stable, continuous, and without any rise or extinguishing.

[0035] Step S106: When it is determined that the burner is in the flame-off state, reduce the speed of the fan to bring the burner into normal combustion state.

[0036] In this embodiment, when the main controller determines that the burner is in a flame-off state, it can send a speed reduction command to the fan to reduce the fan speed, thereby allowing the burner to return to a normal combustion state.

[0037] To facilitate understanding, this embodiment provides two methods for reducing fan speed, which will be described in detail below.

[0038] Method 1 for reducing fan speed: The fan speed is directly reduced to a preset speed value so that the flame bar can quickly return to normal combustion from the flame-off state; the preset speed value can be a preset empirical value or it can be determined through experimental testing.

[0039] Optionally, the preset speed value can be determined as follows: with the gas pressure adjusted to a set pressure value, the highest speed value of the fan when the flame does not detach is obtained experimentally, and the preset speed value is determined based on this highest speed value; wherein, the set pressure value can be from 400 Pa to 700 Pa, for example, the set pressure value is 500 Pa. The preset speed value can be the highest speed value, or it can be the product of the highest speed value and a preset speed correction coefficient, wherein the speed correction coefficient is less than 1, and for example, the range of the speed correction coefficient can be 0.7-0.8; or, the preset speed value can be the highest speed value minus a preset margin speed value, and for example, the range of the margin speed value can be 200 rpm to 600 rpm.

[0040] Alternatively, considering that reducing the preset speed value is sufficient to eliminate flame detachment caused by excessive airflow velocity, if the flame status signal still indicates that the burner is in a flame detachment state after reducing the preset speed value, it is highly likely that the flame detection element itself is malfunctioning or its signal acquisition circuit is abnormal. Based on this, the above-mentioned gas water heater control method further includes: when the fan speed is reduced to the preset speed value and the burner is still determined to be in a flame detachment state, determining that the flame detection element has malfunctioned and providing fault feedback.

[0041] In practice, after determining that the flame detection device has malfunctioned, a specific fault code can be generated and output to the display module of the gas water heater. Furthermore, the gas water heater can be shut down. This enables rapid location and feedback of abnormalities in the flame detection device, improving the maintainability and safety of the gas water heater.

[0042] It should be noted that this embodiment does not limit the specific method of fault feedback. In some possible embodiments, fault feedback may be one or more of the following combinations: display feedback (such as displaying fault codes on the display module), indicator light feedback (such as lighting or flashing fault indicator lights), sound feedback (such as triggering a buzzer alarm or broadcasting fault information via voice), and communication feedback (such as sending fault notifications to the corresponding terminal via wireless or wired means).

[0043] Method 2 for reducing fan speed: The fan speed is gradually reduced to avoid combustion oscillation caused by excessively large single speed reductions (severe fluctuations in air pressure). Specifically, the main controller can control the fan speed to gradually decrease to a first preset speed. After each reduction of the first preset speed, it reassesses whether the burner is still in a flame-off state. If so, the first preset speed is reduced again until the burner is in a normal combustion state or the fan speed drops to a preset minimum allowable speed. Both the first preset speed and the minimum allowable speed are related to the model of the gas water heater.

[0044] Specifically, both the first preset speed and the minimum permissible speed can be determined based on the rated speed of the fan under the rated load corresponding to the gas water heater model. For example, for models with a fan speed of 3000 rpm or higher under rated load, the first preset speed can be set to 100 rpm to 200 rpm, and the minimum permissible speed can be 1000 rpm to 1500 rpm; for models with a fan speed of less than 3000 rpm under rated load, the first preset speed can be set to 50 rpm to 100 rpm, and the minimum permissible speed can be 600 rpm to 1000 rpm. For example, the first preset speed can also be 2% to 5% of the fan's rated speed, and the minimum permissible speed can be 30% to 50%.

[0045] The first preset speed and the minimum permissible speed can also be determined through experimental testing on the corresponding model of gas water heater: with the gas pressure adjusted to the set pressure value, the highest speed value of the fan when the flame does not detach is obtained experimentally, and the first preset speed and the minimum permissible speed are determined based on this highest speed value; the set pressure value can be from 400 Pa to 700 Pa, for example, a set pressure value of 500 Pa. When relatively far from the minimum permissible speed, a larger speed (e.g., 200 rpm) is used for the first preset speed to quickly move away from the danger zone; when relatively close to the minimum permissible speed, a smaller speed (e.g., 50 rpm) is used for fine adjustment. The method for determining the minimum permissible speed is the same as the method for determining the preset speed value, and will not be repeated here.

[0046] Alternatively, considering that reducing the speed to the minimum permissible speed is sufficient to eliminate flame detachment caused by excessive airflow velocity, if the flame status signal still indicates that the burner is in a flame detachment state after reducing the speed to the minimum permissible speed, it is highly likely that the flame detection element itself is malfunctioning or its signal acquisition circuit is abnormal. Based on this, the above-mentioned gas water heater control method further includes: when the fan speed is reduced to the minimum permissible speed and the burner is still determined to be in a flame detachment state, determining that the flame detection element has malfunctioned and providing fault feedback.

[0047] In practice, after each reduction in fan speed, the main controller can start or reset a timer to wait for a preset stabilization time (e.g., 1 to 3 seconds, the specific time can be set according to the fan inertia and combustion chamber pressure stabilization time) to ensure that the combustion state has stabilized. After the waiting time, the flame status signal is acquired again to determine the flame lift-off state. If the flame lift-off state is still detected, the current fan speed is further checked to see if it is less than or equal to the minimum allowable speed. If the current fan speed is less than or equal to the minimum allowable speed, a fault feedback is sent to the flame detection device. If the fan speed is greater than the minimum allowable speed, the fan speed is reduced again. If the flame lift-off state is determined to be normal combustion, the fan speed reduction process ends. The specific implementation method of fault feedback can be referred to the corresponding content in the aforementioned implementation method one for reducing fan speed, and will not be repeated here.

[0048] This application provides a gas water heater control method. By acquiring flame status signals through a flame detection device, it can quickly detect whether flame detachment has occurred in the burner, thereby promptly reducing the fan speed to weaken airflow disturbance and restore normal combustion. This significantly shortens the delay time from flame detachment to fan speed adjustment response, effectively solving the problem of localized flame detachment or even flameout under low load operation or low gas pressure conditions, and significantly improving the combustion stability of the gas water heater.

[0049] Example 2: This embodiment provides another gas water heater control method, which is implemented based on the first embodiment described above. In this embodiment, the flame detection element can be an ion sensing needle, and the flame detection element includes a first detection element located in the flame stabilization zone of the burner and a second detection element located in the flame detachment zone of the burner. This embodiment focuses on describing the specific implementation method of reducing the fan speed due to flame detachment in the gas water heater control method, and the speed recovery method after the burner returns to normal combustion state following the reduction in fan speed due to flame detachment. See also Figure 2 The flowchart shown represents another method for controlling a gas water heater, which includes the following steps: Step S202: Obtain the first signal detected by the first detection element and the second signal detected by the second detection element.

[0050] Optionally, the first detection element is a main feedback needle, and the second detection element is a flame lift-off feedback needle. For example... Figure 3 and Figure 4As shown, in this embodiment, the gas water heater includes a burner assembly 31, a main feedback needle 32, a flame detachment feedback needle 33, a fan 34, and a main controller 35. The burner assembly 31 includes a burner 311. The main feedback needle 32 is disposed in the flame stabilization area above the burner 311, and the flame detachment feedback needle 33 is disposed in the flame detachment area above the burner 311. The first signal includes a first sampled value detected by the main feedback needle 32, and the second signal includes a second sampled value detected by the flame detachment feedback needle 33.

[0051] The aforementioned flame stability zone refers to the area where the flame burns normally under the set operating conditions, while the flame lift-off zone refers to the area where flame lift-off occurs under the set operating conditions. The set operating conditions are defined as the fan 34 operating at its standard speed corresponding to the demand load, and the gas pressure before the gas supply is adjusted to a set pressure value, which can range from 400 Pa to 700 Pa. The demand load here refers to the energy required by the gas water heater to heat water to the target temperature under the current inlet water temperature, the set outlet water temperature (i.e., the user's set temperature), and the water flow rate. In other words, the demand load can be calculated based on the current inlet water temperature, the set outlet water temperature, and the water flow rate. The standard speed refers to the speed set by the fan when the gas water heater is operating normally under the demand load.

[0052] Specifically, the installation positions of the main feedback needle 32 and the flame detachment feedback needle 33 can be determined through experiments: control the gas water heater to work under the demand load to ensure that the fan 34 works at the standard speed corresponding to the demand load, adjust the gas front pressure to the set pressure value (such as 500 Pa), observe the flame detachment of the burner 311 at this time, and take the position with the most severe flame detachment as the installation position of the flame detachment feedback needle 33, and take the position with normal flame combustion as the installation position of the main feedback needle 32.

[0053] In practice, the main controller 35 can periodically or time-divisionally read the analog signals output by the main feedback pin 32 and the flame feedback pin 33 through its analog-to-digital conversion interface, and convert these analog signals into digital (AD) values ​​that can be processed by the processor, i.e., obtain the first sample value and the second sample value. The signal reading period of the main controller 35 can be set according to actual needs, such as once per second or once every 10 seconds, etc., which is not limited in this embodiment.

[0054] Step S204: Determine the flame lift-off state of the fire bar based on the first signal and the second signal.

[0055] In this embodiment, the first signal can indicate whether a flame exists in the flame-stable region, and the second signal can indicate whether a flame exists in the flame-detachment region. Therefore, the determination of the flame-detachment state depends on the joint analysis of the first and second signals. One possible judgment logic is as follows: When the first signal is less than or equal to a preset first threshold, and the second signal is greater than or equal to a preset second threshold, it is determined that the fire bar is in a flame-off state; wherein the second threshold is greater than the first threshold. When the first signal is less than or equal to the first threshold, and the second signal is less than or equal to the first threshold, it is determined that the burner is in normal combustion state; When the first signal is less than or equal to the first threshold, and the second signal is greater than the first threshold and less than the second threshold, it is determined that the burner is still in the state of the previous judgment; that is, if the burner was in the flame-off state in the previous judgment, the burner is still in the flame-off state in this case; if the burner was in the normal combustion state in the previous judgment, the burner is still in the normal combustion state in this case. When the first signal is greater than or equal to the second threshold, and the second signal is greater than or equal to the second threshold, it is determined that the burner is in the flameout state; When the first signal is greater than the first threshold and less than the second threshold, and the second signal is greater than or equal to the second threshold, it is determined that the burner is in the state of the previous judgment. That is, if the burner was in the extinguished state in the previous judgment, the burner is still in the extinguished state in this judgment; if the burner was in the flame-off state in the previous judgment, the burner is still in the flame-off state in this judgment. When the first signal is greater than the first threshold and the second signal is less than the second threshold, it is determined that the flame detection device is faulty.

[0056] The first threshold and the second threshold mentioned above are both preset empirical values. For example, the first threshold is 10 and the second threshold is 250.

[0057] Step S206: When it is determined that the burner is in normal combustion state and the fan speed reaches the standard speed corresponding to the required load, the currently calculated heat load value is used as the reference heat load value, and the heat load threshold is determined based on the reference heat load value.

[0058] After the gas water heater is initialized or successfully enters steady-state combustion, the main controller performs calibration of the reference heat load value. Only when the burner is in normal combustion and the fan is running at standard speed is the current heat load value considered a reliable reference heat load value.

[0059] The heat load threshold is determined based on the baseline heat load value. For ease of understanding, this embodiment provides two methods for calculating the heat load threshold, which will be described in detail below.

[0060] Method 1 for calculating heat load threshold: The heat load threshold is the product of the baseline heat load value and a preset load correction factor; wherein the load correction factor is less than 1. Optionally, the load correction factor can range from 0.4 to 0.6, for example, a load correction factor of 0.5. This method allows for flexible adjustment of the sensitivity when determining the recovery of the fan speed.

[0061] Method 2 for calculating heat load threshold: The heat load threshold is equal to the baseline heat load value minus a preset fixed offset; the fixed offset can be determined based on the minimum heat load of the gas water heater or the fluctuation range in historical operating data. This method is suitable for gas water heater models with strict limitations on the absolute value of the heat load.

[0062] Step S208: When it is determined that the fire bar is in the flame-off state, the speed of the control fan is gradually reduced by the first preset speed.

[0063] Once flame lift-off is detected, the main controller immediately executes the process of reducing the fan speed. Details not described in detail here can be found in the corresponding content of the aforementioned Embodiment 1, and will not be repeated here.

[0064] Step S210: When the burner is in the flame-off state and the first preset rotation speed is gradually reduced, and it is determined that the burner is in normal combustion state, the current heat load value is obtained.

[0065] After each speed reduction operation, wait for the preset stabilization time. Once the combustion state is stable, re-acquire the flame status signal and confirm whether the burner has returned to normal combustion state. When it is determined that the burner has returned to normal combustion state, the main controller can obtain the current heat load value, which is used to determine whether the requirements for restoring the fan speed are met.

[0066] The current heat load value can be calculated by the main controller based on the current inlet water temperature, the current outlet water temperature, and the water flow rate, or it can be read by the main controller from the heat load calculation module (which can calculate the heat load value in real time). The formula for calculating the current heat load value is Q = (T2 - T1) × L, where Q represents the heat load value, T2 represents the outlet water temperature, T1 represents the inlet water temperature, and L represents the water flow rate.

[0067] Step S212: When the current heat load value is greater than or equal to the heat load threshold, restore the fan speed.

[0068] After confirming that the flame combustion state has returned to normal, it is necessary to further confirm whether the heat load has reached the requirement for restoring the fan speed. If the current heat load value is less than the heat load threshold, it indicates that the current operation is still under low load conditions, and the fan speed will not be restored. If the current heat load value reaches the heat load threshold, it indicates that the gas pressure has recovered or the combustion state has recovered to a level sufficient to support a larger load (such as demand load), and the fan speed can be restored. The heat load threshold is determined based on the baseline heat load value when the burner is in normal combustion state before the fan speed decreases due to flame detachment. The specific calculation method for the heat load threshold can be found in the corresponding content of step S206, which will not be repeated here.

[0069] Similar to reducing the fan speed, restoring the fan speed can also be achieved in the following two ways: Method 1 for restoring fan speed: This method directly restores the fan speed to the standard speed corresponding to the required load in one go. It offers a fast response and is suitable for scenarios where gas pressure suddenly rises and optimal combustion conditions need to be quickly restored.

[0070] Method 2 for restoring fan speed: The fan speed is gradually increased by a second preset speed. After each increase of the second preset speed, it is re-evaluated whether the burner is still in normal combustion and whether the current heat load value is still greater than or equal to the heat load threshold. If so, the second preset speed is increased again until the fan speed reaches the standard speed corresponding to the required load.

[0071] During the recovery process, if the burner is in a flame-off state, or if the burner is in normal combustion but the current heat load value is less than the heat load threshold, or if the fan speed reaches the standard speed, then the fan speed will not be restored. The fan speed will only be increased if all three conditions are met simultaneously: the burner is in normal combustion, the current heat load value is still greater than or equal to the heat load threshold, and the fan speed has not reached the standard speed. This method, through step-by-step speed increase, effectively avoids flame-off or combustion oscillations caused by a sudden increase in fan speed, thus improving combustion stability.

[0072] The method for determining the second preset speed is similar to the method for determining the first preset speed, and will not be repeated here.

[0073] This application provides a gas water heater control method. By using a first signal detected by a first detection element and a second signal detected by a second detection element to determine the flame detachment status, it can quickly detect whether flame detachment has occurred in the burner. This effectively solves the flameout phenomenon caused by the lag in fan speed reduction when the gas pressure drops rapidly, thus ensuring stable and normal combustion of the gas water heater under low gas pressure conditions, without resonance and with quiet and comfortable operation. Furthermore, after the fan speed is reduced due to flame detachment, the fan speed is restored based on the normal combustion state of the burner and the current heat load value. This ensures that the fan speed reliably returns to the standard speed after the gas pressure recovers, avoiding premature speed restoration that could induce flame detachment again or low combustion efficiency due to delayed recovery. This achieves fully closed-loop control of the fan speed, further improving the operational robustness and combustion stability of the gas water heater under varying operating conditions.

[0074] Example 3: This embodiment also provides another gas water heater control method, which is implemented based on the above-described embodiment two. In this embodiment, the flame detection element adopts... Figure 3 and Figure 4The main feedback needle 32 and the flame-off feedback needle 33 have a first threshold of 10, a second threshold of 250, and a first preset rotation speed denoted as n revolutions per minute. The working principle of this gas water heater control method is as follows: During normal operation of the gas water heater, all the burner holes of the burner 311 are in a stable combustion state. At this time, the inlet water temperature T 11 and the user-set outlet water temperature T set Keeping it unchanged, the main controller 35 follows the formula Q1=(T) 21 -T 11 ) × L1 to calculate the real-time energy value (i.e., the current heat load value) Q1, where T 21 L1 represents the current outlet water temperature, and L2 represents the current water flow rate. Under this stable combustion state, the first sampled value AD1 detected by the main feedback needle 32 is ≤10, and the second sampled value AD2 detected by the flame-off feedback needle 33 is ≤10.

[0075] When the gas pressure in the gas water heater suddenly decreases, the flame shape changes, and the AD values ​​of the main feedback needle 32 and the flame detachment feedback needle 33 change accordingly. When the first sampled value AD1 ≤ 10 and the second sampled value AD2 ≥ 250, it indicates that the flame at the flame detachment feedback needle 33 has detached, posing a risk of flameout. At this time, the main controller 35 immediately sends a speed adjustment command to the fan 34, controlling the fan speed to decrease by n revolutions per minute until the first sampled value AD1 ≤ 10 and the second sampled value AD2 ≤ 10, indicating that the flame has returned to stable combustion after reducing the fan speed. If the fan speed of 34 is reduced to the minimum allowable speed and the burner is still judged to be in a flame detachment state, then the flame detachment feedback needle 33 will provide fault feedback.

[0076] When the fan speed of 34 is reduced due to flame detachment, and the flame has returned to stable combustion, the main controller 35 calculates according to the formula Q2=(T 22 -T 12 ) × L2 to calculate the real-time energy value (i.e., the current heat load value) Q2, where T 22 T represents the current outlet water temperature. 12 L1 represents the current inlet water temperature, and L2 represents the current water flow rate. Q2 is compared to the heat load threshold (i.e., Q1 × m), where m is the load correction factor (the value of m can be obtained through experimental calibration, e.g., m = 0.5). If Q2 ≥ Q1 × m, it indicates that the gas pressure has recovered to a level sufficient to support the original load operation. At this point, the main controller 35 controls the fan 34 to gradually restore to the standard speed corresponding to the required load, and then continues into the flameout state detection cycle.

[0077] Based on the above working principle, the following will combine Figure 5 The specific flow of the gas water heater control method provided in this embodiment is described below. See [link to documentation]. Figure 5The diagram shows a control logic flowchart for a gas water heater control method, which includes the following steps: Step S502: Obtain AD1 and AD2.

[0078] Step S504: Determine whether AD1≤10 and AD2≥250 are satisfied. If yes (i.e., the burner is in the flame-off state), proceed to step S506; if no (this only refers to the burner being in the normal combustion state), proceed to step S512.

[0079] Step S506: Determine whether the fan speed is less than or equal to the minimum allowable speed. If yes, proceed to step S508; if no, proceed to step S510.

[0080] Step S508: Perform fault feedback for the flame feedback needle.

[0081] In step S510, the fan speed is reduced by n revolutions per minute. Then, step S502 is executed again.

[0082] Step S512: Determine whether the fan speed has reached the standard speed. The standard speed refers to the speed corresponding to the demand load. If yes, proceed to step S514; otherwise, proceed to step S516.

[0083] Step S514, update Q1, Q1 = (T 21 -T 11 ×L1. Then, repeat step S502.

[0084] Step S516, calculate Q2, Q2 = (T 22 -T 12 )×L2.

[0085] Step S518: Determine whether Q2≥Q1×m is satisfied. If yes, proceed to step S520; otherwise, repeat step S502.

[0086] In step S520, the fan speed is increased by n revolutions per minute. Then, step S502 is executed again.

[0087] Example 4: Corresponding to the above method embodiments, this application provides a gas water heater control device. In this embodiment, the gas water heater includes a burner, a flame detection element, a fan, and a main controller. The flame detection element is disposed in the flame combustion area above the burner, and the main controller is connected to both the flame detection element and the fan; this device is applied to the main controller. See also... Figure 6 The diagram shows a structural schematic of a gas water heater control device, which includes: The signal acquisition module 61 is used to acquire the flame status signal of the fire row detected by the flame detection element; The flame lift-off detection module 62 is used to determine the flame lift-off status of the fire bar based on the flame status signal. The speed control module 63 is used to reduce the fan speed when it is determined that the burner is in a flame-off state, so as to keep the burner in a normal combustion state.

[0088] This application provides a gas water heater control device that acquires flame status signals through a flame detection element. This allows for rapid detection of flame detachment from the burner, enabling timely reduction of the fan speed to mitigate airflow disturbance and restore normal combustion. This significantly shortens the delay time from flame detachment to fan speed adjustment response, effectively solving the problem of localized flame detachment or even flameout under low load or low gas pressure conditions, and significantly improving the combustion stability of the gas water heater.

[0089] Furthermore, the flame detection device includes a first detection device located in the flame stabilization region of the fire bar and a second detection device located in the flame lift-off region of the fire bar; based on this, the flame lift-off detection module 62 is specifically used to: determine the flame lift-off state of the fire bar based on the first signal detected by the first detection device and the second signal detected by the second detection device.

[0090] Furthermore, the first detection element is a main feedback needle, and the second detection element is a flame detachment feedback needle. The main feedback needle is located in the flame stabilization area above the fire bar, and the flame detachment feedback needle is located in the flame detachment area above the fire bar. The first signal includes the first sampled value detected by the main feedback needle, and the second signal includes the second sampled value detected by the flame detachment feedback needle.

[0091] Furthermore, the aforementioned flame stable region is the region where the flame burns normally under the set operating conditions, and the flame-off region is the region where flame-off occurs under the set operating conditions; wherein, the set operating conditions are the conditions where the fan operates at the standard speed corresponding to the demand load, and the gas front pressure is adjusted to the set pressure value, and the set pressure value ranges from 400 Pa to 700 Pa.

[0092] Furthermore, the flame lift-off detection module 62 is also used to: determine that the fire bar is in a flame lift-off state when the first signal is less than or equal to a preset first threshold and the second signal is greater than or equal to a preset second threshold; wherein the second threshold is greater than the first threshold.

[0093] Furthermore, the flame lift-off detection module 62 is also used to: determine that the burner is in normal combustion state when the first signal is less than or equal to the first threshold and the second signal is less than or equal to the first threshold; and determine that the burner is still in the state of the previous judgment when the first signal is less than or equal to the first threshold and the second signal is greater than the first threshold and less than the second threshold.

[0094] Furthermore, the aforementioned speed control module 63 is specifically used to: control the speed of the fan to gradually decrease to a first preset speed; wherein, after each decrease to the first preset speed, it is re-determined whether the burner is still in the flame-off state; if so, the first preset speed is decreased again until the burner is in normal combustion state or the speed of the fan drops to the preset minimum allowable speed.

[0095] Furthermore, the aforementioned gas water heater control device also includes: The fault feedback module is used to determine that the flame detection element has malfunctioned and to provide fault feedback when the fan speed drops to the minimum allowable speed and the flame burner is still judged to be in the flame-off state.

[0096] Furthermore, the aforementioned gas water heater control device also includes: The load acquisition module is used to acquire the current heat load value; The aforementioned speed control module 63 is also used to: restore the fan speed when the current heat load value is greater than or equal to the heat load threshold; wherein the heat load threshold is determined based on the reference heat load value when the burner is in normal combustion state before the fan speed decreases due to flame lift-off.

[0097] Furthermore, the aforementioned gas water heater control device also includes: The baseline update module is used to use the currently calculated heat load value as the baseline heat load value when it is determined that the burner is in normal combustion state and the fan speed has reached the standard speed corresponding to the demand load.

[0098] Furthermore, the aforementioned speed control module 63 is also used to: control the fan speed to increase the second preset speed sequentially; wherein, after each increase of the second preset speed, it is re-determined whether the burner is still in normal combustion state and whether the current heat load value is still greater than or equal to the heat load threshold; if so, the second preset speed is increased again until the fan speed reaches the standard speed corresponding to the required load.

[0099] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the gas water heater control device described above can be referred to the corresponding process in the aforementioned embodiments of the gas water heater control method, and will not be repeated here.

[0100] Example 5: This application also provides a gas water heater, which includes a burner, a flame detection element, a fan, and a main controller. The flame detection element is disposed in the flame combustion area above the burner, and the main controller is connected to the flame detection element and the fan respectively. The main controller is used to execute the gas water heater control method in the aforementioned method embodiments.

[0101] Optionally, such as Figure 3 and Figure 4As shown, the flame detection device may include a main feedback needle 32 and a flame detachment feedback needle 33. The main feedback needle 32 is disposed in the flame stabilization area above the flame bar 311, and the flame detachment feedback needle 33 is disposed in the flame detachment area above the flame bar 311.

[0102] This application provides a gas water heater that uses a flame detection device to acquire flame status signals, enabling rapid detection of flame detachment from the burner. This allows for timely reduction of the fan speed to mitigate airflow disturbance and restore normal combustion. This significantly shortens the delay time from flame detachment to fan speed adjustment response, effectively solving the problem of localized flame detachment or even flameout under low load or low gas pressure conditions, and significantly improving the combustion stability of the gas water heater.

[0103] The gas water heater provided in this application embodiment has the same implementation principle and technical effect as the aforementioned gas water heater control method embodiment. For the sake of brevity, any parts not mentioned in the gas water heater embodiment can be referred to the corresponding content in the aforementioned gas water heater control method embodiment.

[0104] The gas water heater control method, device, and computer program product for gas water heaters provided in this application include a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods in the preceding method embodiments. For specific implementation details, please refer to the method embodiments, which will not be repeated here.

[0105] Unless otherwise specifically stated, the relative steps, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application.

[0106] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0107] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way to make the description concise. Not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0108] The specific embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for controlling a gas water heater, characterized in that, A gas water heater includes a burner, a flame detection element, a fan, and a main controller. The flame detection element is located in the flame combustion area above the burner, and the main controller is connected to both the flame detection element and the fan. The gas water heater control method is applied to the main controller, and the gas water heater control method includes: Acquire the flame state signal of the fire bar detected by the flame detection device; The flame state of the fire bar is determined based on the flame state signal. When it is determined that the burner is in a flame-off state, the speed of the fan is reduced so that the burner is in a normal combustion state.

2. The gas water heater control method according to claim 1, characterized in that, The flame detection device includes a first detection device disposed in the flame stabilization region of the fire bar and a second detection device disposed in the flame lift-off region of the fire bar; the step of determining the flame lift-off state of the fire bar based on the flame state signal includes: The flame lift-off state of the fire bar is determined based on the first signal detected by the first detection device and the second signal detected by the second detection device.

3. The gas water heater control method according to claim 2, characterized in that, The first detection element is a main feedback needle, and the second detection element is a flame detachment feedback needle. The main feedback needle is located in the flame stabilization area above the fire bar, and the flame detachment feedback needle is located in the flame detachment area above the fire bar. The first signal includes a first sampled value detected by the main feedback needle, and the second signal includes a second sampled value detected by the flame detachment feedback needle.

4. The gas water heater control method according to claim 2, characterized in that, The flame stable region is the region where the flame burns normally under the set operating conditions, and the flame detachment region is the region where flame detachment occurs under the set operating conditions; wherein, the set operating conditions are the conditions in which the fan operates at the standard speed corresponding to the demand load, and the gas front pressure is adjusted to a set pressure value, and the set pressure value ranges from 400 Pa to 700 Pa.

5. The gas water heater control method according to claim 2, characterized in that, The step of determining the flame lift-off state of the fire bar based on the first signal detected by the first detection device and the second signal detected by the second detection device includes: When the first signal is less than or equal to a preset first threshold, and the second signal is greater than or equal to a preset second threshold, the fire bar is determined to be in a flame-off state; wherein the second threshold is greater than the first threshold.

6. The gas water heater control method according to claim 5, characterized in that, The step of determining the flame lift-off state of the fire bar based on the first signal detected by the first detection element and the second signal detected by the second detection element further includes: When the first signal is less than or equal to the first threshold, and the second signal is less than or equal to the first threshold, it is determined that the burner is in a normal combustion state; When the first signal is less than or equal to the first threshold, and the second signal is greater than the first threshold and less than the second threshold, it is determined that the fire bar is still in the state of the previous judgment.

7. The gas water heater control method according to claim 1, characterized in that, The reduction of the fan speed includes: The speed of the fan is controlled to decrease gradually from a first preset speed; Each time the first preset rotation speed is reduced, it is re-evaluated whether the burner is still in the flame-off state; if so, the first preset rotation speed is reduced again until the burner is in normal combustion state or the fan speed drops to the preset minimum allowable speed.

8. The gas water heater control method according to claim 7, characterized in that, The gas water heater control method also includes: When the fan speed drops to the minimum allowable speed, and the flame bar is still determined to be in a flame-off state, the flame detection device is determined to have malfunctioned, and fault feedback is provided.

9. The gas water heater control method according to any one of claims 1 to 8, characterized in that, After determining that the burner is in a flame-off state and reducing the fan speed, and after determining that the burner is in a normal combustion state, the gas water heater control method further includes: Obtain the current heat load value; When the current heat load value is greater than or equal to the heat load threshold, the fan speed is restored; wherein the heat load threshold is determined based on the reference heat load value when the burner is in normal combustion state before the fan speed decreases due to flame lift-off.

10. The gas water heater control method according to claim 9, characterized in that, The gas water heater control method also includes: When it is determined that the burner is in normal combustion state and the fan speed reaches the standard speed corresponding to the required load, the currently calculated heat load value is used as the reference heat load value.

11. The gas water heater control method according to claim 9, characterized in that, The heat load threshold is the product of the reference heat load value and a preset load correction coefficient; wherein the load correction coefficient is less than 1.

12. The gas water heater control method according to claim 9, characterized in that, The process of restoring the fan speed includes: The fan speed is controlled to increase by a second preset speed successively; Each time the second preset speed is increased, it is re-evaluated whether the burner is still in normal combustion state and whether the current heat load value is still greater than or equal to the heat load threshold. If so, the second preset speed is increased again until the fan speed reaches the standard speed corresponding to the required load.

13. A control device for a gas water heater, characterized in that, A gas water heater includes a burner, a flame detection element, a fan, and a main controller. The flame detection element is located in the flame combustion area above the burner, and the main controller is connected to both the flame detection element and the fan. The gas water heater control device is applied to the main controller, and the gas water heater control device includes: The signal acquisition module is used to acquire the flame state signal of the fire row detected by the flame detection device; The flame lift-off detection module is used to determine the flame lift-off status of the fire bar based on the flame status signal. The speed control module is used to reduce the speed of the fan when it is determined that the burner is in a flame-off state, so as to keep the burner in a normal combustion state.

14. A gas-fired water heater, characterized in that, The device includes a burner, a flame detection element, a fan, and a main controller. The flame detection element is disposed in the flame combustion area above the burner, and the main controller is connected to both the flame detection element and the fan. The main controller is used to execute the gas water heater control method according to any one of claims 1 to 12.

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