Control method and control system for gas water heater

Abstract

The present invention provides a control method and control system for a gas water heater, which belongs to the technical field of constant temperature gas water heater control. The control method for a gas water heater includes: determining the current load based on the current water flow, the current water inlet temperature, the current water outlet temperature and a preset heating coefficient; determining the current wind pressure alarm value based on the current load, and the minimum load, maximum load, the wind pressure alarm value of the minimum load and the wind pressure alarm value of the maximum load corresponding to the current number of fire grates turned on; when the current wind pressure value is greater than or equal to the current wind pressure alarm value, controlling the fan to increase the speed, and / or turning on at least one fire grate that is in a closed state to improve the wind resistance. The control method for a gas water heater of the present invention avoids false alarms and improves the accuracy of the alarm by improving the wind resistance, so that users can use the gas water heater safely.

Description

Technical Field

[0001] The present invention relates to the technical field of constant temperature gas water heater control, and in particular to a control method and a control system for a gas water heater. Background Art

[0002] Currently, when a gas water heater detects a water flow signal from a water flow sensor, it controls the fan to turn on and discharge exhaust gas from the gas water heater through the smoke exhaust duct. If the smoke exhaust duct is blowing normally, the wind pressure switch in the smoke exhaust duct closes. After the wind pressure switch closes, the gas is ignited and burned to heat the water. However, if the wind is strong or the smoke exhaust duct is blocked, making the air unsuitable for gas combustion (for example, flame overflow or excessive carbon monoxide concentration due to incomplete combustion), the gas water heater will issue an alarm signal.

[0003] However, due to the influence of different installation environment factors (for example, the length of the smoke outlet duct, or whether there are gusts of wind outside the smoke outlet duct), it is easy for the alarm to be triggered too early, too late, or inaccurate under the influence of gusts of wind, making it impossible for users to use the gas water heater safely. Summary of the Invention

[0004] In view of the shortcomings of the existing methods, this application provides a control method and control system for a gas water heater to solve the technical problems in the existing technology that the gas water heater is affected by different installation environment factors, resulting in inaccurate alarms and the inability of users to use the gas water heater safely.

[0005] In the first aspect, an embodiment of the present application provides a control method for a gas water heater, the control method comprising: determining the current load based on the current water flow rate, the current water inlet temperature, the current water outlet temperature and a preset heating coefficient; determining the minimum load, maximum load, wind pressure alarm value of the minimum load and wind pressure alarm value of the maximum load corresponding to the current number of fire grates turned on in the correspondence between the preset number of fire grates, minimum load, maximum load, wind pressure alarm value of the minimum load and wind pressure alarm value of the maximum load; determining the current wind pressure alarm value based on the current load and the minimum load, maximum load, wind pressure alarm value of the minimum load and wind pressure alarm value of the maximum load corresponding to the current number of fire grates turned on; when the current wind pressure value is greater than or equal to the current wind pressure alarm value, controlling the fan to increase the speed, and / or turning on at least one fire grate that is in a closed state to improve wind resistance.

[0006] As an optional implementation, after controlling the fan to increase the speed, it also includes: if the current working current of the gas proportional valve is less than or equal to the preset limiting current, controlling the gas proportional valve to operate at the limiting current; the limiting current is the sum of the working current of the gas proportional valve and the preset buffer current value when the current number of fire gears turned on operates at the minimum load.

[0007] As an optional implementation, before turning on at least one fire bar in a closed state, it also includes: if the minimum load corresponding to the target number of fire bars to be turned on is greater than the current load, determining the target water outlet temperature based on the difference between the current load and the minimum load corresponding to the target number of fire bars to be turned on, the current water flow, the current water inlet temperature and the preset heating coefficient; if the difference between the target water outlet temperature and the current water outlet temperature is less than or equal to the preset temperature difference, turning on at least one fire bar in a closed state so that the number of fire bars in the turned-on state reaches the target number of fire bars to be turned on.

[0008] As an optional implementation method, the control method also includes: if the minimum load corresponding to the target number of fire bars turned on is less than the current load, and the maximum load corresponding to the target number of fire bars turned on is greater than the current load, then determining the target water outlet temperature based on the difference between the maximum load corresponding to the target number of fire bars turned on and the current load, the current water flow, the current water inlet temperature and the preset heating coefficient; if the difference between the target water outlet temperature and the current water outlet temperature is less than or equal to the preset temperature difference, then turning on at least one fire bar that is in a closed state so that the number of fire bars in an open state reaches the target number of fire bars turned on.

[0009] As an optional implementation, the control method further includes: if the current load is less than or equal to the limit load, controlling the fan to operate at a first speed; the limit load is the product of a preset ratio and a maximum load corresponding to the current number of fire bars turned on; if the current load is greater than the limit load, controlling the fan to operate at a second speed; the first speed is less than the second speed.

[0010] As an optional implementation, the formula for determining the current load based on the current water flow, the current inlet water temperature, the current outlet water temperature and the preset heating coefficient is: P 当前 =L×(T 出水 -T 进水 ) / K; where P 当前 is the current load, L is the current water flow, T 进水 is the current inlet water temperature, T 出水 is the current water outlet temperature, and K is the preset heating coefficient.

[0011] As an optional implementation, the formula for determining the current wind pressure alarm value based on the current load, the minimum load, the maximum load, the wind pressure alarm value at the minimum load, and the wind pressure alarm value at the maximum load corresponding to the number of fire bars currently turned on is: 报警 =(F 大 -F 小 )×[(P 当前 -P 小 ) / (P 大 -P 小 )]+F 小 Among them, F 报警 is the current wind pressure alarm value, F 大 is the wind pressure alarm value at maximum load, F 小 is the wind pressure alarm value of minimum load, P 当前 is the current load, P 大 is the maximum load, and P is the minimum load.

[0012] As an optional implementation, after controlling the fan to increase the speed and / or turning on at least one fire bar that is in a closed state, it also includes: repeatedly executing the determination of the current load based on the current water flow, the current water inlet temperature, the current water outlet temperature and the preset heating coefficient until the water is determined to be turned off.

[0013] As an optional implementation manner, the control method further includes: outputting an alarm signal if the duration that the current wind pressure value is greater than or equal to the current wind pressure alarm value is greater than or equal to a preset warning duration.

[0014] In a second aspect, an embodiment of the present application provides a control system for a gas water heater, comprising: a current load determination module for determining the current load based on the current water flow, the current water inlet temperature, the current water outlet temperature and a preset heating coefficient; a data determination module for determining the minimum load, maximum load, wind pressure alarm value of the minimum load and wind pressure alarm value of the maximum load corresponding to the number of fire grates currently turned on, in the correspondence between the preset number of fire grates, minimum load, maximum load, wind pressure alarm value of the minimum load and wind pressure alarm value of the maximum load; a current wind pressure alarm value determination module for determining the current wind pressure alarm value based on the current load, the minimum load, maximum load, wind pressure alarm value of the minimum load and wind pressure alarm value of the maximum load corresponding to the number of fire grates currently turned on; a control module for controlling the fan to increase the speed or turn on more fire grates to improve the wind resistance when the current wind pressure value is greater than or equal to the current wind pressure alarm value.

[0015] This application provides a control method and control system for a gas water heater. The technical solutions provided by the embodiments of this application bring at least the following beneficial effects:

[0016] The specific current wind pressure value is detected by the wind pressure sensor, and the appropriate wind pressure alarm value is determined according to the current wind pressure value, that is, the current wind pressure alarm value is adjusted according to different current usage states to avoid false alarms; when the current partial pressure is greater than or equal to the current wind pressure alarm value, the fan is controlled to increase the speed, and / or at least one fire grate in the closed state is turned on to improve the wind resistance and avoid alarms, so that users can continue to use the gas water heater safely, thereby improving user experience.

[0017] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0019] Figure 1 A schematic structural diagram of a gas water heater provided in an embodiment of the present application;

[0020] Figure 2 A schematic diagram showing the relationship between the number of open fire bars and the corresponding load in a gas water heater control method provided in an embodiment of the present application;

[0021] Figure 3 This is a flow chart of an example of a gas water heater control method provided in an embodiment of the present application;

[0022] Figure 4 A schematic diagram showing the corresponding relationship between the number of open fire strips, minimum load, maximum load, wind pressure alarm value at minimum load, and wind pressure alarm value at maximum load in a gas water heater control method provided in an embodiment of the present application;

[0023] Figure 5 A schematic diagram of the framework structure of a gas water heater control system provided in an embodiment of the present application.

[0024] The reference numerals and corresponding descriptions are as follows:

[0025] 1: Shell;

[0026] 2: Water flow channel;

[0027] 3: Smoke outlet channel;

[0028] 4: fan;

[0029] 5: Wind pressure sensor;

[0030] 10: Current load determination module;

[0031] 20: data determination module;

[0032] 30: Current wind pressure alarm value determination module;

[0033] 40: Control module. DETAILED DESCRIPTION

[0034] The present application is described in detail below. Examples of embodiments of the present application are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar components or components having the same or similar functions. In addition, if the detailed description of the known technology is not necessary for the features of the present application shown, it will be omitted. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0035] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0036] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of this application refers to the presence of the features, integers, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, operations, elements, components and / or groups thereof. It should be understood that when we say that an element is "connected" to another element, it can be directly connected to the other element, or there may be intermediate elements. In addition, the "connection" used here may include wireless connection.

[0037] An embodiment of the present application provides a control method for a gas water heater, which is applicable to a gas water heater with a constant temperature function.

[0038] The structure of gas water heater is as follows Figure 1As shown, the gas water heater includes a shell 1, which has a cavity (not marked in the figure), a water flow channel 2 is arranged in the cavity, and a water inlet temperature sensor (not marked in the figure) is arranged at the water inlet end of the water flow channel 2 for detecting the current water inlet temperature; a water flow sensor (not marked in the figure) is arranged on the water flow channel 2 for detecting the current water flow; a water outlet temperature sensor (not marked in the figure) is arranged at the water outlet end of the water flow channel 2 for detecting the current water outlet temperature; the gas water heater also includes a smoke outlet channel 3 connecting the shell 1 and the external environment, and a fan 4 and a wind pressure sensor 5 are arranged in the smoke outlet channel 3, and the wind pressure sensor 5 is used to detect the current wind pressure value.

[0039] A burner (not shown) is also located within the cavity to heat the water in water channel 2. The burner includes a gas pipeline equipped with a proportional gas valve to control the gas flow rate. The burner also includes multiple fire bars and solenoid valves to control the opening and closing of the fire bars. Each fire bar is connected to the gas pipeline.

[0040] In a specific embodiment, the burner includes six fire bars, which can be respectively the first fire bar, the second fire bar, the third fire bar, the fourth fire bar, the fifth fire bar and the sixth fire bar. In order to facilitate the control of opening different numbers of fire bars according to different load requirements, for example, the first fire bar and the second fire bar are normally open fire bars, the third fire bar and the fourth fire bar are controlled by the first solenoid valve, and the fifth fire bar and the sixth fire bar are controlled by the second solenoid valve. When two fire bars need to be opened for heating, the gas proportional valve is opened and the first solenoid valve and the second solenoid valve are closed; when four fire bars need to be opened for heating, the gas proportional valve and the first solenoid valve are opened, and the second solenoid valve is closed; when two fire bars need to be opened for heating, the gas proportional valve, the first solenoid valve and the second solenoid valve are all opened.

[0041] The relationship between the number of open fire bars and the corresponding load is shown in the following diagram: Figure 2 As shown in the figure, PL is the minimum opening of the gas proportional valve corresponding to the number of fire chips, that is, the minimum load. The minimum opening corresponds to the operating current of one gas proportional valve. PH is the maximum opening of the gas proportional valve corresponding to the number of fire chips, that is, the maximum load. The maximum opening corresponds to the operating current of one gas proportional valve.

[0042] The gas water heater further comprises a controller (not shown in the figure), which is electrically connected to and controls the water inlet temperature sensor, the flow sensor, the water outlet temperature sensor, the wind pressure sensor 5 and the burner.

[0043] like Figure 3 As shown, the control method of the gas water heater mainly includes steps S1-S4:

[0044] Step S1: determining the current load based on the current water flow, the current inlet water temperature, the current outlet water temperature and a preset heating coefficient;

[0045] Step S2: According to the current number of fire bars that are turned on, determine the minimum load, maximum load, minimum load wind pressure alarm value, and maximum load wind pressure alarm value corresponding to the current number of fire bars that are turned on in the preset correspondence relationship between the number of fire bars, minimum load, maximum load, minimum load wind pressure alarm value, and maximum load wind pressure alarm value;

[0046] Step S3: Determine the current wind pressure alarm value based on the current load, the minimum load, the maximum load, the wind pressure alarm value at the minimum load, and the wind pressure alarm value at the maximum load corresponding to the number of fire bars currently turned on;

[0047] Step S4: When the current wind pressure value is greater than or equal to the current wind pressure alarm value, control the fan 4 to increase the rotation speed, and / or open at least one fire bar that is in a closed state to improve the wind resistance.

[0048] The control method for the gas water heater provided in the embodiment of the present application first determines the current wind pressure, and then determines the current wind pressure alarm value under the current usage environment based on the current wind pressure, that is, adjusts the current wind pressure alarm value according to different current usage states to avoid false alarms; when the current partial pressure is greater than or equal to the current wind pressure alarm value, the fan 4 is controlled to increase the speed, and / or, at least one fire grate in the closed state is turned on to improve the wind resistance and avoid alarms, so that users can continue to use the gas water heater safely, thereby improving user experience.

[0049] In one possible embodiment, the maximum heating power of the gas water heater is 23 kilowatts, which is equivalent to a water flow rate of 13 liters per minute, and a maximum heating temperature of 25 degrees Celsius; when the power is 1 kilowatt and the water flow rate is 1 liter per minute, the maximum heating can be 14 degrees, and 14 is the preset heating coefficient in the above step 1; when the air pressure is too high, the heating coefficient is greater than 14; otherwise, the heating coefficient is less than 14.

[0050] As an optional implementation, the formula for determining the current load in step 1 according to the current water flow, the current inlet water temperature, the current outlet water temperature and the preset heating coefficient is:

[0051] P 当前 =L×(T 出水 -T 进水 ) / K;

[0052] Among them, P 当前 is the current load, L is the current water flow, T 进水 is the current inlet water temperature, T 出水 is the current outlet water temperature, and K is the preset heating coefficient.

[0053] In some possible embodiments, the corresponding relationship among the number of fire bars opened in the aforementioned step 2, the minimum load, the maximum load, the wind pressure alarm value at the minimum load, and the wind pressure alarm value at the maximum load can be obtained through a large number of experiments.

[0054] The corresponding relationship among the number of open fire bars, minimum load, maximum load, wind pressure alarm value at minimum load and wind pressure alarm value at maximum load is as follows: Figure 4 As shown in the figure, for the same number of open fire bars, the wind pressure alarm value at the minimum load is different from the wind pressure alarm value at the maximum load; for the same number of open fire bars, the alarm wind pressure value is proportional to the load, that is, the alarm wind pressure value is proportional to the gas proportional valve current.

[0055] As an optional implementation, in the aforementioned step 3, the formula for determining the current wind pressure alarm value based on the current load, and the minimum load, maximum load, wind pressure alarm value at the minimum load, and wind pressure alarm value at the maximum load corresponding to the current number of fire bars turned on is:

[0056] F 报警 =(F 大 -F 小 )×[(P 当前 -P 小 ) / (P 大 -P 小 )]+F 小 ;

[0057] Among them, F 报警 is the current wind pressure alarm value, F 大 is the wind pressure alarm value at maximum load, F 小 is the wind pressure alarm value of minimum load, P 当前 is the current load, P 大 is the maximum load, and P is the minimum load.

[0058] according to Figure 4 In the data, when the number of open fire rows is 4, F 报警 =(36-24)×[(P-6) / (13-6)]+24.

[0059] As an optional implementation manner, the control method of the gas water heater further includes:

[0060] Collect the current outlet water temperature at the preset collection cycle;

[0061] If the current outlet water temperature is greater than the preset first temperature value, the current control current of the gas proportional valve is reduced; if the current outlet water temperature is less than the preset second temperature value, the current control current of the gas proportional valve is increased.

[0062] The first temperature value is the sum of the target temperature value and the temperature difference value. The second temperature value is the difference between the target temperature value and the temperature difference value. The target temperature value is a user-set value. Optionally, the preset acquisition period is 1 second. Optionally, the temperature difference value can be 0.1 degrees Celsius.

[0063] During the operation of the gas water heater, the current outlet water temperature is collected at a preset collection cycle to detect the outlet water temperature. If the current outlet water temperature is greater than a preset first temperature value, the current control current of the gas proportional valve is reduced to reduce the valve opening, thereby lowering the outlet water temperature. If the current outlet water temperature is less than a preset second temperature value, the current control current of the gas proportional valve is reduced to increase the valve opening, thereby raising the outlet water temperature. The adjusted outlet water temperature is greater than or equal to the second temperature and less than or equal to the first outlet water temperature, ensuring that the outlet water temperature remains constant with minimal fluctuations, ensuring a constant temperature experience for the user.

[0064] As an optional implementation manner, after controlling the fan 4 to increase the speed, the control method of the gas water heater further includes the steps of:

[0065] If the current operating current of the gas proportional valve is less than or equal to the preset limiting current, the gas proportional valve is controlled to operate at the limited current.

[0066] The limiting current is the sum of the operating current of the gas proportional valve and a preset buffer current value when the number of currently opened fire grates is operating at minimum load. Optionally, the buffer current value is 5 mA.

[0067] After controlling the fan 4 to increase the speed, the exhaust fire power increases and the wind pressure will rise accordingly. If the control current of the gas proportional valve at this time is the current when the current number of fire exhausts turned on is running at the minimum load, the flameout phenomenon may easily occur. In order to ensure the stability of flame combustion, the working current of the gas proportional valve can be increased, that is, the opening of the gas proportional valve can be increased to increase the gas flow rate, but the outlet water temperature may rise. In order to ensure that the load is not easily adjusted downward, the aforementioned temperature difference is increased when controlling the gas proportional valve to limit the current, thereby ensuring the constant temperature effect; optionally, the temperature difference is increased from the aforementioned 0.1 degrees Celsius to 2 degrees Celsius.

[0068] As an optional implementation manner, before turning on at least one fire grate that is in a closed state, the control method of the gas water heater further includes the steps of:

[0069] If the minimum load corresponding to the target number of fire bars turned on is greater than the current load, the target water outlet temperature is determined based on the difference between the current load and the minimum load corresponding to the target number of fire bars turned on, the current water flow, the current water inlet temperature and the preset heating coefficient;

[0070] If the difference between the target outlet water temperature and the current outlet water temperature is less than or equal to the preset temperature difference, at least one fire bar in the closed state is opened so that the number of fire bars in the open state reaches the target number of open fire bars.

[0071] According to the above embodiment, a possible embodiment is provided, in which the number of currently opened fire bars is 4 rows, the target number of opened fire bars is 6 rows, and the preset temperature difference is 2 degrees Celsius. If it is necessary to increase to 6 rows, it is first necessary to determine whether the load corresponding to the 6 rows will cause the outlet water temperature to increase or reduce the preset temperature difference, that is, whether the constant temperature effect can be guaranteed. The current load corresponding to the 4 rows of fire bars is 8 kilowatts, and the minimum load corresponding to the 6 rows of fire bars is 10 kilowatts. The 10 kilowatts is less than the maximum load of 13 kilowatts corresponding to the 4 rows of fire bars, so the difference of 10 kilowatts - 8 kilowatts = 2 kilowatts is obtained. According to the formula P = L × (T 出水 -T 进水 ) / K, we know that the temperature change corresponding to 2 kW is △T = 2 × 14 / L. Therefore, whether the temperature exceeds 2 degrees Celsius depends primarily on the current water flow rate. If the temperature change is less than or equal to the preset temperature difference, the second solenoid valve is controlled to open the fifth and sixth fire bars, reaching the target number of six fire bars, and heating is performed at the minimum load. Otherwise, the closed fire bars are not opened.

[0072] As an optional implementation, the control method of the gas water heater further includes the steps of:

[0073] If the minimum load corresponding to the target number of fire bars turned on is less than the current load, and the maximum load corresponding to the target number of fire bars turned on is greater than the current load, the target water outlet temperature is determined based on the difference between the maximum load corresponding to the target number of fire bars turned on and the current load, the current water flow rate, the current water inlet temperature and the preset heating coefficient;

[0074] If the difference between the target outlet water temperature and the current outlet water temperature is less than or equal to the preset temperature difference, at least one fire bar in the closed state is opened so that the number of fire bars in the open state reaches the target number of open fire bars.

[0075] According to the above embodiment, a possible embodiment is provided. The number of currently opened fire bars is 4, the target number of opened fire bars is 6, and the preset temperature difference is 2 degrees Celsius. The current load corresponding to the 4 fire bars is 13 kilowatts, the minimum load corresponding to the 6 fire bars is 10 kilowatts, and the 10 kilowatts is less than the current load of 13 kilowatts. The maximum load corresponding to the 6 fire bars is 23 kilowatts, and the 23 kilowatts is greater than the current load of 13 kilowatts. The difference of 23 kilowatts - 13 kilowatts = 10 kilowatts is obtained according to the formula P = L × (T 出水 -T 进水) / K, we know that the temperature change corresponding to 10 kW is △T = 10 × 14 / L. Therefore, whether the temperature exceeds 2 degrees Celsius depends primarily on the current water flow rate. If the temperature change is less than or equal to the preset temperature difference, the second solenoid valve is controlled to open the fifth and sixth fire bars, reaching the target number of 6 fire bars, and heating at maximum load. Otherwise, the closed fire bars are not opened.

[0076] As an optional implementation manner, the control method of the gas water heater further includes:

[0077] If the current load is less than or equal to the limit load, the fan 4 is controlled to run at the first speed;

[0078] If the current load is greater than the limit load, the fan 4 is controlled to run at the second speed.

[0079] The critical load serves as the basis for switching between the first and second speed levels. If the current load is less than or equal to the critical load, fan 4 is controlled to operate at the first speed level; if the current load is greater than the critical load, fan 4 is controlled to operate at the second speed level. The first speed level is less than the second speed level. The critical load is the product of a preset ratio and the maximum load corresponding to the number of currently active fire bars; optionally, the preset ratio is 70 percent.

[0080] Optionally, the fan 4 is an AC fan 4 having two wind speed gears, namely a first low speed gear and a second high speed gear.

[0081] Optionally, the first gear speed is greater than or equal to 1900 revolutions per minute and less than or equal to 2100 revolutions per minute.

[0082] Optionally, the second gear speed is greater than or equal to 2700 revolutions per minute and less than or equal to 2900 revolutions per minute.

[0083] As an optional implementation, after the aforementioned step S4 controls the fan 4 to increase its speed, and / or turns on at least one fire grate that is in a closed state, the control method of the gas water heater further includes:

[0084] Repeat the process of determining the current load based on the current water flow, the current inlet water temperature, the current outlet water temperature and the preset heating coefficient until the water is shut off.

[0085] During the entire operation of the gas water heater, the current load and the current wind pressure alarm value are continuously determined, and when the current wind pressure value is greater than or equal to the current wind pressure alarm value, the fan 4 is controlled to increase the speed, and / or, at least one fire grate that is in the closed state is turned on, and the aforementioned steps S1-S4 are repeatedly executed in a cycle until the user turns off the water, that is, the user ends use.

[0086] As an optional implementation manner, the control method of the gas water heater further includes:

[0087] If the current wind pressure value is greater than or equal to the current wind pressure alarm value and the duration is greater than or equal to the preset warning time, an alarm signal is output.

[0088] During the operation of the gas water heater, the relationship between the current wind pressure value and the current wind pressure alarm value is continuously determined. If the current wind pressure value is greater than or equal to the current wind pressure alarm value and the duration is greater than or equal to the preset warning time, it means that the current wind pressure is not suitable for the operation of the gas water heater, and safety problems such as flame overflow and excessive carbon monoxide caused by insufficient gas combustion may occur. The alarm signal is output to remind users to pay attention to safety. The device can also shut down after outputting the alarm signal.

[0089] Optionally, the duration is 5 seconds.

[0090] As an optional embodiment, before the above step S1 determines the current load according to the current water flow, the current inlet water temperature, the current outlet water temperature and the preset heating coefficient, the control method of the gas water heater further includes:

[0091] After the fan 4 is controlled to start, if the time duration during which the current wind pressure value is greater than or equal to the start wind pressure alarm value is greater than the preset time duration, the burner is controlled to ignite.

[0092] After fan 4 is started, if smoke outlet duct 3 is blocked, air pressure sensor 5 will not detect air pressure. If the front air pressure value is greater than or equal to the start-up air pressure alarm value for longer than the preset time, smoke outlet duct 3 is not blocked and ignition can proceed normally. The start-up air pressure alarm value is related to the ignition load. If the ignition load is the medium load of 4 rows (6 + 13) / 2 = 9.5 kilowatts), the start-up air pressure alarm value is (24 + 36) / 2 = 30 Pa.

[0093] Based on the same inventive concept, an embodiment of the present application provides a control system for a gas water heater, which mainly includes a current load determination module 10, a data determination module 20, a current wind pressure alarm value determination module 30, and a control module 40. The current load determination module 10 is used to determine the current load based on the current water flow rate, the current water inlet temperature, the current water outlet temperature, and a preset heating coefficient; the data determination module 20 is used to determine the minimum load, maximum load, minimum load wind pressure alarm value, and maximum load wind pressure alarm value corresponding to the number of currently turned on fire bars based on the preset correspondence between the number of fire bars, the minimum load, the maximum load, the wind pressure alarm value at the minimum load, and the wind pressure alarm value at the maximum load; the current wind pressure alarm value determination module 30 is used to determine the current wind pressure alarm value based on the current load, the minimum load, the maximum load, the wind pressure alarm value at the minimum load, and the wind pressure alarm value at the maximum load corresponding to the number of currently turned on fire bars; and the control module 40 is used to control the fan 4 to increase its speed or turn on more fire bars to improve wind resistance when the current wind pressure value is greater than or equal to the current wind pressure alarm value.

[0094] The control system of the gas water heater provided in the embodiment of the present application avoids false alarms by first determining the current wind pressure, and then determining the current wind pressure alarm value under the current usage environment based on the current wind pressure; when the current partial pressure is greater than or equal to the current wind pressure alarm value, the fan 4 is controlled to increase the speed, and / or, at least one fire grate that is in a closed state is turned on to improve the wind resistance, thereby avoiding alarms, allowing users to continue to use the water heater, increasing the user's continuous usage time, and thus improving the user experience.

[0095] The specific definitions of the gas water heater control system can be found in the definitions of the gas water heater control method above and will not be repeated here. Each module in the aforementioned gas water heater control system can be implemented in whole or in part through software, hardware, or a combination thereof. Each of these modules can be embedded in or independent of a processor in a computer device in hardware form, or stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0096] This application provides a control method and control system for a gas water heater. The technical solutions provided by the embodiments of this application bring at least the following beneficial effects:

[0097] The specific current wind pressure value is detected by the wind pressure sensor 5, and the adaptive wind pressure alarm value is determined according to the current wind pressure value, that is, the current wind pressure alarm value is adjusted according to different current usage states to avoid false alarms; when the current partial pressure is greater than or equal to the current wind pressure alarm value, the fan 4 is controlled to increase the speed, and / or, at least one fire grate in the closed state is turned on to improve the wind resistance and avoid alarms, so that users can continue to use the gas water heater safely, thereby improving user experience.

[0098] Those skilled in the art will appreciate that the steps, measures, and schemes in the various operations, methods, and processes discussed in this application may be interchanged, modified, combined, or deleted. Furthermore, other steps, measures, and schemes in the various operations, methods, and processes discussed in this application may also be interchanged, modified, rearranged, decomposed, combined, or deleted. Furthermore, steps, measures, and schemes in the prior art that are similar to those disclosed in this application may also be interchanged, modified, rearranged, decomposed, combined, or deleted.

[0099] 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 the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0100] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0101] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0102] It should be understood that although the steps in the flowcharts of the accompanying drawings are shown in sequence as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in the flowcharts of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0103] The above description is only part of the implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for controlling a gas water heater, characterized in that: The control method includes: Determine the current load based on the current water flow, current inlet water temperature, current outlet water temperature and the preset heating coefficient; According to the current number of fire bars that are turned on, determine the minimum load, maximum load, minimum load wind pressure alarm value and maximum load wind pressure alarm value corresponding to the current number of fire bars that are turned on in the preset correspondence between the number of fire bars, minimum load, maximum load, minimum load wind pressure alarm value and maximum load wind pressure alarm value; Determine the current wind pressure alarm value based on the current load, and the minimum load, maximum load, wind pressure alarm value at the minimum load, and wind pressure alarm value at the maximum load corresponding to the current number of fire bars opened; When the current wind pressure value is greater than or equal to the current wind pressure alarm value, controlling the fan (4) to increase the rotation speed, and / or opening at least one fire bar that is in a closed state to improve the wind resistance; After the fan (4) is controlled to increase its rotation speed and / or at least one fire bar in a closed state is turned on, the method further comprises: repeatedly performing the method of determining the current load according to the current water flow, the current inlet water temperature, the current outlet water temperature and the preset heating coefficient until the water is turned off; After the fan (4) is controlled to increase its speed, the method further comprises: If the current operating current of the gas proportional valve is less than or equal to the preset limiting current, the gas proportional valve is controlled to operate at the limiting current; the limiting current is the sum of the operating current of the gas proportional valve and the preset buffer current value when the current number of open fire gears operates at the minimum load; Before opening at least one fire bar in a closed state, the method further includes: If the minimum load corresponding to the target number of fire bars turned on is greater than the current load, the target water outlet temperature is determined based on the difference between the current load and the minimum load corresponding to the target number of fire bars turned on, the current water flow rate, the current water inlet temperature and the preset heating coefficient; If the difference between the target outlet water temperature and the current outlet water temperature is less than or equal to the preset temperature difference, at least one closed fire bar is opened so that the number of opened fire bars reaches the target number of opened fire bars.

2. The method according to claim 1, characterized in that The control method further includes: If the minimum load corresponding to the target number of fire bars turned on is less than the current load, and the maximum load corresponding to the target number of fire bars turned on is greater than the current load, the target water outlet temperature is determined according to the difference between the maximum load corresponding to the target number of fire bars turned on and the current load, the current water flow rate, the current water inlet temperature and the preset heating coefficient; If the difference between the target outlet water temperature and the current outlet water temperature is less than or equal to the preset temperature difference, at least one closed fire bar is opened so that the number of opened fire bars reaches the target number of opened fire bars.

3. The method according to claim 1, characterized in that The control method further includes: If the current load is less than or equal to the limit load, the fan (4) is controlled to operate at a first speed; the limit load is the product of a preset ratio and a maximum load corresponding to the number of currently opened fire bars; If the current load is greater than the limit load, the fan (4) is controlled to operate at a second speed; the first speed is less than the second speed.

4. The control method according to claim 1, wherein: The formula for determining the current load based on the current water flow, the current inlet water temperature, the current outlet water temperature and the preset heating coefficient is: P 当前 =L×(T 出水 -T 进水 ) / K; Among them, P 当前 is the current load, L is the current water flow, T 进水 is the current inlet water temperature, T 出水 is the current water outlet temperature, and K is the preset heating coefficient.

5. The control method according to claim 1, characterized in that: The formula for determining the current wind pressure alarm value based on the current load, and the minimum load, maximum load, wind pressure alarm value at the minimum load, and wind pressure alarm value at the maximum load corresponding to the current number of fire bars opened is: F 报警 =(F 大 -F 小 ) ×[(P 当前 -P 小 ) / (P 大 -P 小 )]+F 小 ; Among them, F 报警 is the current wind pressure alarm value, F 大 is the wind pressure alarm value at maximum load, F 小 is the wind pressure alarm value of minimum load, P 当前 is the current load, P 大 is the maximum load, P 小 For the minimum load.

6. The control method according to any one of claims 1 to 5, characterized in that: The control method further includes: If the duration that the current wind pressure value is greater than or equal to the current wind pressure alarm value is greater than or equal to the preset warning duration, an alarm signal is output.

7. A control system for a gas water heater, characterized in that: include: A current load determination module (10) is used to determine the current load based on the current water flow rate, the current water inlet temperature, the current water outlet temperature and a preset heating coefficient; A data determination module (20) is used to determine, based on the number of fire bars currently turned on, the minimum load, the maximum load, the wind pressure alarm value at the minimum load, and the wind pressure alarm value at the maximum load corresponding to the number of fire bars currently turned on, from a preset correspondence relationship among the number of fire bars, the minimum load, the maximum load, the wind pressure alarm value at the minimum load, and the wind pressure alarm value at the maximum load; A current wind pressure alarm value determination module (30) is used to determine the current wind pressure alarm value based on the current load, the minimum load, the maximum load, the wind pressure alarm value at the minimum load, and the wind pressure alarm value at the maximum load corresponding to the number of fire bars currently turned on; A control module (40) is used to control the fan (4) to increase the rotation speed or open more fire bars to improve wind resistance when the current wind pressure value is greater than or equal to the current wind pressure alarm value; After the fan (4) is controlled to increase its rotation speed and / or at least one fire bar that is in a closed state is turned on, the control module (40) is further configured to repeatedly execute the step of determining the current load based on the current water flow, the current inlet water temperature, the current outlet water temperature and the preset heating coefficient until the water is turned off; After the fan (4) is controlled to increase its speed, the method further comprises: If the current operating current of the gas proportional valve is less than or equal to the preset limiting current, the gas proportional valve is controlled to operate at the limiting current; the limiting current is the sum of the operating current of the gas proportional valve and the preset buffer current value when the current number of open fire gears operates at the minimum load; Before opening at least one fire bar in a closed state, the method further includes: If the minimum load corresponding to the target number of fire bars turned on is greater than the current load, the target water outlet temperature is determined based on the difference between the current load and the minimum load corresponding to the target number of fire bars turned on, the current water flow, the current water inlet temperature and the preset heating coefficient.

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