Gas water heater preheating control method, gas water heater and hot water circulation system

Abstract

This application relates to a preheating control method for a gas water heater, a gas water heater, and a hot water circulation system. The method includes: upon receiving a first instruction, acquiring the resistance of the circulation pipeline, determining and storing the preheating circulation flow rate q4 of the gas water heater based on the resistance of the circulation pipeline; upon receiving a second instruction, controlling the operation of the circulating water pump based on the preheating circulation flow rate q4, so that the real-time circulation flow rate q5 in the circulation pipeline is equal to the preheating circulation flow rate q4. By matching the corresponding preheating circulation flow rate q4 according to the resistance of the circulation pipeline where the water heater is located, the circulating water pump can operate at an appropriate speed according to the corresponding preheating circulation flow rate during the preheating process, reducing the noise generated by the circulating water pump, extending the service life of the circulating water pump, and improving the user experience.

Description

Technical Field

[0001] This application relates to the field of water heater technology, and in particular to a preheating control method for a gas water heater, a gas water heater and a hot water circulation system. Background Technology

[0002] Related zero-cold-water gas water heaters have a circulating heating function, which can circulate and heat the cold water in the pipes to the required hot water temperature, so that hot water flows out as soon as the water heater is turned on, greatly improving the user experience in winter.

[0003] Because different households have varying floor areas and pipe lengths, a high-power, high-head circulating water pump is needed to ensure smooth circulation in all homes and meet diverse needs. However, circulating water pumps generate significant noise when operating at rated power. To guarantee the circulating water flow and preheating speed after the zero-cold-water water heater is turned on, the circulating water pump typically operates at high speed. But for most households with shorter pipes, the circulation pipes and their resistance are far below design values. Operating the circulating water pump at high speed results in considerable noise, and the increased power of the pump further increases operating costs. Summary of the Invention

[0004] One of the technical problems addressed by this application is to provide a preheating control method that can solve the problem of high noise levels in pipelines.

[0005] The second technical problem addressed by this application is to provide a gas water heater that can solve the problem of complex control.

[0006] The third technical problem addressed by this application is to provide a hot water circulation system that can solve the problem of limited applicability.

[0007] The first technical problem mentioned above is solved by the following technical solution:

[0008] A preheating control method, comprising:

[0009] After receiving the first instruction, the resistance of the circulation pipeline is obtained, and the preheating circulation flow rate q4 of the gas water heater is determined and saved based on the resistance of the circulation pipeline.

[0010] Upon receiving the second instruction, the operation of the circulating water pump is controlled according to the preheating circulation flow rate q4, so that the real-time circulation flow rate q5 in the circulation pipeline is equal to the preheating circulation flow rate q4.

[0011] The preheating control method in the above embodiments suffers from different water flow resistances due to varying pipe conditions among users. This means that under the same pump operating conditions, the circulating flow rate within the pipes of different users will typically differ. Therefore, the circulating flow rate reflects the user's pipe condition under the same pump operating conditions. Thus, the preheating control method of this application determines the appropriate preheating circulation flow rate based on the resistance of the circulating pipe where the water heater is located. This allows the circulating pump to match the appropriate speed during the preheating process. Compared to the method where the circulating pump operates at high speed at rated power regardless of the pipe condition, this preheating control method reduces operating noise and extends the service life of the circulating pump, thus improving the user experience, even in areas with better pipe conditions.

[0012] In one embodiment, it further includes:

[0013] Multiple preset resistance levels;

[0014] Different appropriate preheating circulation flow rates correspond to different preset resistance levels;

[0015] Determine and store the preheating circulation flow rate q4 of the gas-fired water heater based on the resistance of the circulation pipeline, including:

[0016] Determine the resistance level of the circulation pipeline based on its resistance characteristics;

[0017] Select the appropriate preheating circulation flow rate value as the preheating circulation flow rate q4 based on the determined resistance level.

[0018] In one embodiment, the resistance of the circulation pipeline is characterized as the difference between the maximum circulation flow rate q1 of the circulation pipeline and the preset minimum start-up flow rate q2 of the gas water heater.

[0019] In one implementation, the maximum circulation flow rate q1 of the circulation pipeline is obtained in the following way:

[0020] Upon receiving the first instruction, control the circulating water pump to operate at its rated power;

[0021] The circulating flow rate of the circulation pipeline is the maximum circulating flow rate q1 of the circulation pipeline.

[0022] In one embodiment, multiple resistance levels are preset, including:

[0023] The preset first level is defined as the difference between the maximum circulation flow q1 and the minimum start flow q2 being greater than or equal to the first threshold.

[0024] The preset second level is defined as the difference between the maximum circulating flow q1 and the minimum starting flow q2 being greater than or equal to the second threshold and less than the first threshold.

[0025] The preset third level is when the difference between the maximum circulation flow q1 and the minimum startup flow q2 is greater than the third threshold but less than the second threshold.

[0026] The preset fourth level is defined as the difference between the maximum circulation flow q1 and the minimum start flow q2 being less than or equal to the third threshold.

[0027] Among them, the first threshold is greater than the second threshold and the second threshold is greater than the third threshold.

[0028] In one embodiment, different suitable preheating circulation flow rates are corresponding to different preset resistance levels, including:

[0029] The circulation pipeline is of the first level, and the preset appropriate preheating circulation flow rate corresponding to the first level is the sum of the minimum start-up flow rate q2 and the first predetermined flow rate X1;

[0030] The circulation pipeline is of the second level, and the preset appropriate preheating circulation flow rate corresponding to the second level is the sum of the minimum start-up flow rate q2 and the second predetermined flow rate X2;

[0031] The circulation pipeline is of the third level, and the preset appropriate preheating circulation flow rate corresponding to the third level is the sum of the minimum start-up flow rate q2 and the third predetermined flow rate X3;

[0032] The circulation pipeline is of the fourth level, and the preset appropriate preheating circulation flow rate corresponding to the fourth level is the maximum circulation flow rate q1.

[0033] Among them, the first predetermined flow rate X1 is greater than the second predetermined flow rate X2, the second predetermined flow rate X2 is greater than the third predetermined flow rate X3, and the third predetermined flow rate X3 is greater than or equal to 0.

[0034] In one embodiment, upon receiving the second instruction, the operation of the circulating water pump is controlled according to the preheating circulation flow rate q4, including:

[0035] When the real-time circulation flow rate q5 is less than the preheating circulation flow rate q4, the circulation pump is controlled to increase the duty cycle at a constant speed to achieve acceleration, with an acceleration frequency of m / 100.

[0036] Obtain the acceleration time of the circulating water pump;

[0037] When the real-time circulation flow rate q5 is equal to the preheating circulation flow rate q4 or the acceleration time is equal to the preset time, the circulating water pump is controlled to run at a constant speed.

[0038] Where m is the time required for the duty cycle of the circulating water pump to increase from 0% to 100%, m is greater than or equal to 2 seconds and less than or equal to 4 seconds, and the maximum circulation flow q1 is the circulation flow rate in the circulation pipeline when the circulating water pump is running at 100% duty cycle.

[0039] The second technical problem mentioned above is solved by the following technical solution:

[0040] A gas water heater includes: a control element, on which a computer program is stored, and when the computer program is executed by the control element, it implements the control method described in the above embodiments.

[0041] The gas water heater described in the above embodiments, and the gas water heater provided in this application, can implement the control method described in the above embodiments. Therefore, the beneficial effects achieved by the gas water heater in this application are the same as those achieved by the control method provided in the above embodiments, and will not be repeated here. Furthermore, the control element can quickly obtain the most suitable preheating circulation flow rate within the pipeline, allowing water to flow through the gas water heater at a suitable preheating circulation flow rate, thus reducing the vibration caused by the impact of the water flow on the internal pipeline of the gas water heater, and reducing the noise generated during the operation of the gas water heater.

[0042] In one embodiment, a first button and a second button are disposed on the surface of the gas water heater, and both the first button and the second button are electrically connected to a control element.

[0043] The first button is used to issue the first command;

[0044] The second button is used to issue a second command.

[0045] The third technical problem mentioned above is solved by the following technical solution:

[0046] A hot water circulation system, comprising:

[0047] The gas water heater as described in the above embodiments;

[0048] External piping, together with the internal piping of the gas water heater, forms a circulation system;

[0049] Circulating water pumps are used to create a circulating water flow within circulating pipelines; and

[0050] Water flow sensor, used to detect the circulating flow rate in a circulation pipeline.

[0051] The hot water circulation system in the above embodiments is the same as the gas water heater in the above embodiments. Therefore, the beneficial effects that the circulation system in this application can achieve are the same as the beneficial effects that the gas water heater provided in the above embodiments can achieve, and will not be repeated here. Attached Figure Description

[0052] Figure 1 This is a schematic diagram illustrating the logic of obtaining the preheating circulation flow rate q4 in a preheating control method provided in an embodiment of this application.

[0053] Figure 2 This is a schematic diagram illustrating the logic of controlling the operation of the circulating water pump using the preheating circulation flow rate q4 in a preheating control method provided in an embodiment of this application.

[0054] Figure 3 This is a schematic diagram of the structure of a gas water heater provided in one embodiment of this application.

[0055] Figure 4 A water circuit diagram of a hot water circulation system provided in an embodiment of this application.

[0056] Figure 5 A water circuit diagram of a hot water circulation system provided in another embodiment of this application.

[0057] Figure label:

[0058] 101. Inlet pipe; 102. Heat exchanger pipe; 103. Outlet pipe; 104. Cold water pipe; 105. Connecting water pipe;

[0059] 106. Return water pipe;

[0060] 11. Water flow sensor;

[0061] 12. Circulating water pump;

[0062] 13. Check valve;

[0063] 200. Intake pipe;

[0064] 30. Gas water heater;

[0065] 31. Display panel; 32. Buttons. Detailed Implementation

[0066] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0067] In the description of this application, it should be understood that if terms such as "length", "upper", "top", "bottom", "inner", "outer", "circumferential", etc. appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0068] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0069] It should be noted that if a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component. If a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0070] Zero-cold-water gas water heaters use a built-in or external circulating water pump to heat the cold water in the pipes to the required hot water temperature. This ensures that hot water is released immediately when the water is turned on, significantly improving the user experience. However, because different users have different pipe lengths and / or pipe layouts, the circulating water flow rate varies even with the same pump. To ensure sufficient circulating water flow and preheating time, the selected circulating water pumps typically have higher power and head to accommodate different user needs and varying pipe flow rates, resulting in higher noise levels during operation. Furthermore, to guarantee sufficient circulating water flow and preheating speed after the zero-cold-water water heater is turned on, the circulating water pump operates at a high speed and maintains this constant speed. For users with short pipes and / or simple pipe layouts, where pipe resistance is lower, high-speed operation of the circulating water pump is unnecessary. Reducing high-speed operation of the circulating water pump reduces combustion noise during high-power operation of the water heater. However, if the circulating water pump operates at too low a speed, users with high pipe resistance will experience low water flow velocity or difficulty in forming a flow within the circulating pipe. The magnitude of pipe resistance is primarily influenced by factors such as pipe length, pipe layout, and pipe diameter. Longer pipes, more bends, and smaller diameters all increase pipe resistance. Conversely, shorter pipes, fewer bends, a more straight pipe profile, and larger diameters all decrease pipe resistance.

[0071] In some embodiments of this application, this application provides a preheating control method suitable for a hot water circulation system, including, after receiving a first instruction, acquiring the resistance of the circulation pipeline, determining the preheating circulation flow rate q4 of the gas-fired water heater based on the resistance of the circulation pipeline, and saving the result.

[0072] Upon receiving the second instruction, the circulating water pump 12 is controlled to operate according to the preheating circulation flow rate q4, so that the real-time circulation flow rate q5 in the circulation pipeline is equal to the preheating circulation flow rate q4.

[0073] Specifically, the resistance of the circulation pipeline is obtained based on the maximum circulation flow rate q1 and the minimum starting flow rate q2 of the gas water heater. The maximum circulation flow rate q1 is the water flow rate detected by the water flow sensor 11 when the circulating water pump 12 is running at its rated power. The minimum starting flow rate q2 is the flow rate through the gas water heater when it is ignited. It is understandable that the gas water heater can only be ignited when the flow rate through it reaches a certain value; this certain flow rate value is the minimum starting flow rate q2 of the gas water heater.

[0074] The principle behind determining a user's piping condition based on the maximum circulation flow rate q1 of the circulation pipeline and the minimum starting flow rate q2 of the gas water heater is as follows: different users have different piping conditions, resulting in varying water flow resistance. This means that under the same operating conditions of the circulating water pump 12, the circulation flow rate within the pipeline will typically differ between users. Therefore, the circulation flow rate within the pipeline reflects the user's piping condition under the same operating conditions of the circulating water pump 12. Thus, the preheating control method in this solution matches the maximum circulation flow rate q1 and the minimum starting flow rate q2 based on the actual situation of the water heater to a corresponding preheating circulation flow rate q4. This allows the circulating water pump 12 to operate at an appropriate speed according to the corresponding circulation flow rate during the preheating process. Compared to circulating water pumps 12 operating at high speeds only at their rated power, the preheating control method in this solution reduces the operating power of the circulating water pump 12 in well-functioning circulation pipelines, thereby reducing its operating noise. Furthermore, reducing the operating power of the circulating water pump 12 effectively extends its service life, thus improving the user experience.

[0075] Specifically, the preheating control method includes learning and preheating circulation. During the learning step, parameters related to pipeline resistance are obtained, and based on the pipeline resistance, a preheating circulation flow rate q4 adapted to the corresponding circulation pipeline is calculated. After learning is complete, in the preheating circulation step, the circulating water pump 12 operates at a corresponding speed so that the real-time circulation flow rate q5 in the circulation pipeline is consistent with the preheating circulation flow rate q4 obtained during learning, and the circulating water pump 12 operates normally at this speed.

[0076] More specifically, the learning steps include: after receiving the first instruction, performing machine learning analysis based on the maximum circulation flow q1 and the minimum start-up flow q2 in the circulation pipeline to obtain the preheating circulation flow q4 required for the gas water heater to preheat, and then exiting the machine learning analysis state.

[0077] The preheating cycle step includes: after receiving the second instruction, sending an acceleration instruction to the circulating water pump 12;

[0078] Obtain the real-time circulating flow rate q5 detected by water flow sensor 11;

[0079] When q5 = q4, a stop acceleration command and a constant speed command are issued to the circulating water pump 12.

[0080] The steps for obtaining the control parameters required for preheating a gas water heater by performing machine learning analysis based on the length of the circulation pipeline include:

[0081] A command is issued to the circulating water pump 12 to operate at rated power;

[0082] Get the maximum loop flow q1;

[0083] The preheating circulation flow rate q4 is determined based on the maximum circulation flow rate q1 and the minimum start-up flow rate q2, where q4 ≤ q1.

[0084] In this solution, the maximum circulation flow rate q1 varies in different circulation pipelines. Specifically, the longer the circulation pipeline and the more complex its layout, the greater the resistance and the smaller the maximum circulation flow rate q1. Based on the maximum circulation flow rate q1, a preheating circulation flow rate q4 suitable for the circulation pipeline can be obtained. The corresponding circulation speed of the circulating water pump 12 is then accurately calculated based on the different circulation pipelines. Specifically, in this application, a water flow sensor 11 detects the flow rate. Based on the flow rate, the water flow sensor 11 feeds back the water flow signal to the control element, which controls the water pump to accelerate or maintain a constant speed. The control element can be a controller or a microcomputer. Based on the water flow signal detected by the water flow sensor 11, the control element controls the circulating water pump 12, achieving precise control of the circulating water pump 12's speed. This achieves preheating while matching the most suitable speed, reducing the noise during the operation of the circulating water pump 12. This solves the problem of excessive noise from the gas water heater 30 during operation, which can be bothersome to users, thus improving the user experience.

[0085] In addition, a water flow sensor 11 is used to detect the water flow rate. The water flow rate depends on the cross-sectional area of ​​the circulation pipe and the water flow velocity, which in turn depends on the resistance of the circulation pipe and the initial velocity provided by the circulating water pump 12. The cross-sectional area and resistance of the circulation pipe are determined by the characteristics of the circulation pipe itself. On the one hand, within the same circulation pipe, the water flow sensor 11 detects both the water flow rate and the water flow velocity provided by the circulating water pump 12, providing a more intuitive reflection of the water flow situation in the circulation pipe. On the other hand, since the water flow rate also depends on the cross-sectional area and resistance of the circulation pipe, even with the same power provided by the circulating water pump 12, different water flow rates in different circulation pipes can reveal the parameters of the circulation pipe. Based on these parameters, the optimal preheating circulation flow rate can be more accurately matched, balancing the circulation speed of the water in the pipe and the noise generated during operation, thus improving the user experience.

[0086] Furthermore, the step of determining the preheating circulation flow rate q4 based on the maximum circulation flow rate q1 and the minimum start-up flow rate q2 includes:

[0087] The resistance level of the circulation pipeline is determined based on the difference between the maximum circulation flow rate q1 and the minimum starting flow rate q2, and a suitable preheating circulation flow rate value is selected as the preheating circulation flow rate q4 based on the determined resistance level. Specifically,

[0088] In order to determine the preheating circulation flow rate q4 of the gas water heater based on the resistance of the circulation pipeline, multiple resistance levels are preset in the control element, and different preset resistance levels correspond to different suitable preheating circulation flow rate values. The corresponding suitable preheating circulation flow rate value is selected as the preheating circulation flow rate q4 based on the determined resistance level.

[0089] The resistance of the circulation pipeline is represented by the difference between the maximum circulation flow rate q1 and the preset minimum start-up flow rate q2 of the gas water heater. Therefore, in this scheme, the resistance level of the circulation pipeline can be determined based on the difference between the maximum circulation flow rate q1 and the minimum start-up flow rate q2, which is q3, and then the preheating circulation flow rate q4 corresponding to the resistance level can be selected.

[0090] This includes setting multiple resistance levels, with different resistance levels corresponding to different suitable preheating circulation flow rates, specifically including:

[0091] When the circulation pipeline is at the first level, it is preset that q3 ≥ the first threshold A1. The appropriate preheating circulation flow rate corresponding to the first level is the sum of the minimum start flow rate q2 of the gas water heater 30 and the first predetermined flow rate X1.

[0092] When the circulation pipeline is at the second level, the second threshold A2 ≤ q3 < the first threshold A1 is preset, and the appropriate preheating circulation flow rate corresponding to the second level is the sum of the minimum start flow rate q2 and the second predetermined flow rate X2;

[0093] When the circulation pipeline is at the third level, the third threshold A3 < q1 < the second threshold A2 is preset, and the appropriate preheating circulation flow rate corresponding to the third level is the sum of the minimum start flow rate q2 and the third predetermined flow rate X3;

[0094] When the circulation pipeline is at the fourth level, it is preset that q3≤the third threshold A3, and the appropriate preheating circulation flow rate value corresponding to the fourth level is q1;

[0095] Wherein, the first threshold A1 > the second threshold A2 > the third threshold A3, and the first predetermined flow rate X1 > the second predetermined flow rate X2 > the third predetermined flow rate X3 ≥ 0.

[0096] Based on the maximum circulation flow rate q1, the resistance of the circulation pipelines for different users is divided into four levels. By comparing the maximum circulation flow rate q1 under different threshold ranges, the corresponding level of the circulation pipeline is determined. Then, the preheating circulation flow rate q4 is calculated according to the calculation rules of the corresponding level, so that the obtained q4 is more adaptable to the corresponding pipeline.

[0097] Furthermore, since the minimum start-up flow rate q2 is a fixed value and does not change with the resistance of the circulation pipeline, according to the formula q3 = q1 - q2, the preheating circulation flow rate q4 can be determined through q1. The specific steps include:

[0098] When q3≥A1, then q1≥A1+q2, and the preheating circulation flow rate q4 is equal to the sum of the minimum start-up flow rate q2 and the second predetermined flow rate X1;

[0099] When A2≤q3<A1, then A2+q2≤q1<A1+q2, and the preheating circulation flow rate q4 is equal to the sum of the minimum start-up flow rate q2 and the third predetermined flow rate X2;

[0100] When A3 < q3 < A2, then A3 + q2 < q1 < A2 + q2, and the preheating circulation flow rate q4 is equal to the sum of the minimum start-up flow rate q2 and the third predetermined flow rate X3;

[0101] When q3≤A3, q1≤A3+q2, and the preheating circulation flow rate q4 equals q1.

[0102] Generally, during installation, the water flow in the circulation pipeline must reach the minimum starting flow rate, i.e., q1 ≥ q2. Since the third threshold A3 is not less than 0, specifically, q3 = 0. Furthermore, according to A1 > A2 > A3 ≥ 0, the smaller the difference between q1 and q2, the greater the resistance in the circulation pipeline; conversely, the larger the difference between q1 and q2, the smaller the resistance in the circulation pipeline. Simultaneously, the smaller the resistance in the circulation pipeline, the larger the predetermined flow rate value (used as a coefficient) in the preheating circulation flow rate q4; conversely, the smaller the resistance in the circulation pipeline, the smaller the predetermined flow rate value (used as a coefficient) in the preheating circulation flow rate q4, in order to balance the circulation flow rate and noise.

[0103] Reference Figure 1 , Figure 1 This diagram illustrates the logic of obtaining the preheating circulation flow rate q4 in a preheating control method provided in one embodiment of this application. For example, when q3 ≥ 2 L / min, the calculation rule q4 = q2 + 1 is executed, and q4 is calculated and saved.

[0104] When 1≤q3<2L / min, perform the calculation procedure q4=q2+0.5, calculate q4 and save q4;

[0105] When 0 < q3 < 1 L / min, execute the calculation procedure q4 = q2, calculate q4 and save q4;

[0106] When q3 = 0, execute the calculation rule of q4 = q1, calculate q4, and save q4.

[0107] The minimum starting flow rate q2 is a fixed value, meaning the initial velocity provided by the circulating water pump 12 depends on the cross-sectional area and resistance of the circulating pipeline. The difference q3 between the maximum circulating flow rate q1 and the minimum starting flow rate q2 allows for a more accurate assessment of the circulating pipeline. For example, a small difference between q1 and q2 indicates higher pipeline resistance, requiring the circulating water pump 12 to operate at greater power to achieve liquid flow, resulting in a smaller difference between q1 and q2 when the pump is operating at maximum power. Conversely, a large difference between q1 and q2 indicates lower pipeline resistance. Using the difference between q1 and q2 to determine pipeline resistance provides broader adaptability to different circulating pipelines and allows for more accurate classification.

[0108] It is understandable that the calculation method for the preheating circulation flow rate q4 corresponding to different resistance levels of the circulation pipeline includes, but is not limited to:

[0109] The circulation pipeline is of the first level, and the preset preheating circulation flow rate q4 corresponding to the first level is the sum of the minimum start-up flow rate q2 and the first predetermined flow rate X1;

[0110] The circulation pipeline is of the second level, and the preset preheating circulation flow rate q4 corresponding to the second level is the sum of the minimum start-up flow rate q2 and the second predetermined flow rate X2;

[0111] The circulation pipeline is at the third level, and the preset preheating circulation flow rate q4 corresponding to the third level is the sum of the minimum start-up flow rate q2 and the third predetermined flow rate X3;

[0112] The circulation pipeline is of the fourth level, and the preheating circulation flow rate q4 corresponding to the fourth level is preset to be the maximum circulation flow rate q1.

[0113] On the one hand, the classification of different resistance levels in the circulation pipeline can be more detailed, resulting in a higher degree of matching between the preheating circulation flow rate q4 and the corresponding circulation pipeline. Since q2 is a fixed value, in this embodiment, the preheating circulation flow rate q4 is obtained by adding q2 to a predetermined flow rate of a fixed value. On the other hand, the calculation method for the preheating circulation flow rate q4 can also be used to calculate the maximum circulation flow rate q1. Since the magnitude of the maximum circulation flow rate q1 is related to the resistance of the circulation pipeline, when the preheating circulation flow rate q4 depends on the maximum circulation flow rate q1, a preheating circulation flow rate q4 that is adaptive to the circulation pipeline can be obtained, resulting in a high degree of matching between the preheating circulation flow rate q4 and the circulation pipeline.

[0114] In some embodiments of this application, reference is made to Figure 2 , Figure 2This diagram illustrates the logic of controlling the operation of the circulating water pump using the preheating circulation flow rate q4 in a preheating control method provided in one embodiment of this application. Upon receiving a second instruction, the circulating water pump 12 is controlled to operate based on the real-time circulation flow rate q5 and the preheating circulation flow rate q4 within the circulation pipeline, including:

[0115] After receiving the second instruction, the real-time circulation flow rate q5 detected by the water flow sensor 11 is obtained. When the real-time circulation flow rate q5 is less than the preheating circulation flow rate q4, an acceleration instruction is sent to the circulating water pump 12. Specifically, the circulating water pump 12 is controlled to increase the duty cycle at a constant speed to achieve acceleration, and the acceleration frequency is m / 100.

[0116] Obtain the acceleration time of circulating water pump 12;

[0117] When the real-time circulation flow rate q5 is equal to the preheating circulation flow rate q4 or the acceleration time is equal to the preset time m, a stop acceleration command and a constant speed command are sent to the circulating water pump 12 to control the circulating water pump 12 to run at a constant speed.

[0118] The circulating water pump 12 accelerates at a constant duty cycle with an acceleration frequency of m / 100. The time required for the duty cycle of the circulating water pump 12 to increase from 0% to 100% is m seconds. For example, if the preset time m = 2 seconds, then it takes 20 milliseconds for the duty cycle to increase by 1% at a constant speed. The constant speed operation of the circulating water pump 12 means that the circulating water pump 12 maintains the current flow rate with a constant duty cycle.

[0119] It is understandable that after obtaining the acceleration time of the circulating water pump 12, the constant duty cycle of the circulating water pump 12 can also be calculated to obtain the actual working power of the circulating water pump 12 when it is running at a constant speed.

[0120] After receiving the second instruction, the step of issuing an acceleration instruction to the circulating water pump 12 further includes:

[0121] After the real-time circulation flow rate q5 is increased to the minimum start-up flow rate q2, the combustion heat exchange device inside the gas water heater 30 is ignited, thereby heating the water flow in the circulation pipeline.

[0122] In this design, the water flow sensor 11 also controls the gas water heater 30 to preheat. When the water flow sensor 11 detects that the real-time circulation flow q5 reaches the minimum starting flow q2, that is, after the liquid begins to flow in the circulation pipe, the water flow sensor 11 controls the gas water heater 30 to ignite and heat, thereby starting the preheating cycle of the circulation pipe. Using the water flow sensor 11 to control the gas water heater 30 ensures that liquid flow and heating occur simultaneously, thus avoiding problems such as dry burning or localized overheating.

[0123] Furthermore, after issuing a stop acceleration command and a constant speed command to the circulating water pump 12, the process also includes:

[0124] When the third instruction is received, control the circulating water pump 12 to stop working;

[0125] Furthermore, when q5 < q2, the combustion heat exchange device inside the gas water heater 30 is shut down.

[0126] When q5 < q2, the liquid in the circulation pipe is in a state of stopped flow or low-speed flow. The water flow sensor 11 controls the gas water heater 30 to stop heating, so as to avoid dry burning or local overheating caused by the slow water flow in the circulation pipe.

[0127] In some embodiments of this application, the step of obtaining the maximum circulating flow q1 includes:

[0128] After sending a command to the circulating water pump 12 to operate at rated power for m seconds, obtain q1.

[0129] Where m is the scheduled time.

[0130] For example, the circulating water pump 12 is a DC brushless water pump. The DC brushless water pump utilizes PWM control, ensuring that the time required for its duty cycle to increase from 0% to 100% is m seconds, where 2s ≤ m ≤ 4s. This allows the DC brushless water pump to accelerate to its rated power more quickly, thereby improving the adaptive matching speed of the water flow within the circulating pipeline. It is understood that the circulating water pump 12 operating at rated power as mentioned in this application means that the circulating water pump 12 operates at a 100% duty cycle, at which point the obtained circulating flow rate is the maximum circulating flow rate q1.

[0131] Furthermore, the step of issuing a stop acceleration command and a constant speed command to the circulating water pump 12 when the preheating circulation flow rate q4 is q1 includes:

[0132] After sending an acceleration command m seconds to the circulating water pump 12, a stop acceleration command and a constant speed command are sent to the circulating water pump 12.

[0133] When q4 = q1 = q2, the resistance of the corresponding circulation pipeline is very high, requiring the circulating water pump 12 to operate at its rated power for the liquid in the circulation pipeline to begin flowing. Specifically, the circulating water pump 12 takes m seconds to reach its rated power after starting, and the time required for the water flow in the circulation pipeline to stabilize and be detected by the water flow sensor 11 will be greater than m seconds. This will cause the circulating water pump 12 to still receive acceleration commands even when operating at its rated power, easily leading to overload. To avoid overload of the circulating water pump 12, another control logic is added to the control method to issue a stop acceleration command and a constant speed command to the circulating water pump 12, so that after the circulating water pump 12 issues the acceleration command m seconds later, it operates at a constant speed at its rated power.

[0134] By using two control conditions, under normal circulation pipeline resistance, the control logic for adjusting the circulating water pump 12 from acceleration to constant speed when q5 = q4 is adopted, and the time spent executing the corresponding action is less than m seconds. However, in special cases where the circulation pipeline resistance is very high, the water flow sensor 11 cannot complete the detection of the water flow in the circulation pipeline within m seconds. In this case, the control logic for adjusting the circulating water pump 12 from acceleration to constant speed after issuing an acceleration command for m seconds is adopted.

[0135] It should be noted that the control logic for adjusting the circulating water pump 12 from an accelerated state to a constant speed state after issuing an acceleration command m seconds later includes, but is not limited to, the case where q4 = q1 = q2. When q3 is approximately 0, the resistance of the corresponding circulation pipeline is also quite large, and there is a possibility that the water flow sensor 11 cannot complete the detection of the water flow in the circulation pipeline within m seconds. Therefore, the control logic for issuing a stop acceleration command and a constant speed command to the circulating water pump 12 after issuing an acceleration command m seconds later will also be adopted. It can be understood that the control logic for adjusting the circulating water pump 12 from an accelerated state to a constant speed state when q5 = q4 is executed first, while the circulating water pump 12 is forcibly adjusted from an accelerated state to a constant speed state m seconds after issuing the acceleration command.

[0136] In some embodiments of this application, in order to implement the preheating control method provided in the above embodiments, this application also provides a control element. The control element stores a computer program, and when the computer program is executed by the control element, it implements the preheating control method described above. The control element includes a processor and a communication interface. The processor can be connected to the circulating water pump 12 and the water flow sensor 11 through the communication interface to realize signal transmission. Optionally, the control element may also include a memory, which stores at least the computer program and the circulating flow rate to facilitate quick recall of the preheating control method.

[0137] The control element provided in this embodiment can implement the control method in the above embodiments. Therefore, the beneficial effects achieved by the control element in this embodiment are the same as those achieved by the control method provided in the above embodiments, and will not be repeated here. In addition, the control element can quickly call the preheating control method. When executing the learning step, it can quickly calculate the most suitable control parameters in the pipeline, write the control parameters into the memory, and directly call the calculated control parameters in subsequent preheating cycles to improve the control accuracy of the control element to adapt to the circulation pipelines of different users, and also improve the response speed.

[0138] In specific embodiments, the processor may include one or more CPUs, each of which may be a single-core processor or a multi-core processor. Here, "processor" may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0139] The memory can be read-only memory (ROM) or other types of static storage devices capable of storing static information and instructions, random access memory (RAM) or other types of dynamic storage devices capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited to these. The memory can exist independently or it can be integrated onto the processor.

[0140] The memory stores the data in this application and the computer execution instructions corresponding to the computer program of this application. The processor can realize various functions of the control element by running or executing the computer program stored in the memory and by calling the data stored in the memory.

[0141] A communication interface, using any transceiver-like device, is used to communicate with other devices or communication networks, such as control systems, radio access networks (RANs), and wireless local area networks (WLANs). A communication interface may include a receiving unit to implement receiving functions and a transmitting unit to implement transmitting functions.

[0142] Optionally, the control element also includes a timer, which can issue a stop acceleration command and a constant speed command to the processor or the circulating water pump 12. By controlling the timer, the circulating water pump 12 can be forcibly adjusted from the acceleration state to the constant speed state m seconds after it issues the acceleration command.

[0143] In some embodiments of this application, see Figure 3 , Figure 3 A schematic diagram of a gas water heater provided in one embodiment of this application is shown. This application also provides a gas water heater 30, which incorporates the control element, combustion heat exchange device, circulating water pump 12, and water flow sensor 11 provided in the above embodiment. The combustion heat exchange device is used to heat a portion of the circulation pipe located within the gas water heater 30. The circulating water pump 12 is used to form a circulating water flow within the circulation pipe. The water flow sensor 11 is used to detect the circulating flow rate within the circulation pipe in real time. Both the water flow sensor 11 and the circulating water pump 12 are electrically connected to the control element. It should be noted that the water flow sensor 11 and the circulating water pump 12 are connected to the control element, including but not limited to electrical connections, via wired connections. The water flow sensor 11, the circulating water pump 12, and the control element can also be communicatively connected, transmitting signals via wireless or wired communication.

[0144] The gas water heater provided in this embodiment includes the control element as described in the above embodiment. Therefore, the beneficial effects that the gas water heater in this embodiment can achieve are the same as the beneficial effects that the control element provided in the above embodiment can achieve, and will not be described again here.

[0145] Furthermore, the gas water heater has buttons 32 on its surface, including a first button and a second button, both of which are electrically connected to a control element. The first button is used to issue a first command, and the second button is used to issue a second and a third command. Specifically, the gas water heater also has a display panel 31 on its surface, which displays the operating parameters of the gas water heater. The buttons 32 are integrated into the display panel 31.

[0146] In one specific embodiment, the learning step includes: after the air in the circulation pipeline is purged, pressing the first button sends a first command to the control element, and the gas water heater 30 begins to execute the learning step to obtain the circulating water flow rate under the current user environment. Simultaneously, pressing the second button causes the circulating water pump 12 to operate at its rated power, and the control element obtains the maximum circulating flow rate q1. After obtaining the maximum circulating flow rate q1, the gas water heater 30 stops working.

[0147] After completing the learning steps, press the second button. The circulating water pump 12 will start running, and its speed will gradually increase. The combustion heat exchange device of the gas water heater 30 will ignite. The real-time circulation flow rate q5 will reach the previously stored circulation flow rate q4 in the control element. The circulating water pump 12 will then stop accelerating and maintain this speed for preheating until preheating is complete. Preheating completion includes pressing the second button again. For example, the second button can be any zero-cold-water function key, such as jog, single cruise, or all-weather.

[0148] In this embodiment, the circulating water pump 12 and the water flow sensor 11 are installed inside the gas water heater 30. The circulation pipeline includes an inlet pipe 101, a heat exchange pipe 102, and an outlet pipe 103, which are connected sequentially. The outlet pipe 103 and the inlet pipe 101 extend from both ends of the heat exchange pipe 102 into the gas water heater 30. The circulating water pump 12 and the water flow sensor 11 are located on the inlet pipe 101. Compared to the heat exchange pipe 102 and the outlet pipe 103, the temperature of the liquid in the inlet pipe 101 is lower. Furthermore, heat continuously dissipates from the hot water flowing out of the heat exchange pipe 102, and after preheating and circulating, the temperature of the hot water drops upon returning to the inlet pipe 101. The circulating water pump 12 and the water flow sensor 11 operate in a lower temperature environment, effectively extending their service life.

[0149] Furthermore, the gas water heater 30 also includes an inlet pipe 200, which extends to the combustion heat exchange device. Gas is supplied to the combustion heat exchange device through the inlet pipe 200, causing the combustion heat exchange device to ignite the gas after ignition, thus maintaining combustion within the gas water heater 30 and heating the liquid in the heat exchange tube 102 to the temperature required by the user. Specifically, controlling the combustion heat exchange device to shut off includes controlling the inlet pipe 200 to prevent the supply of gas to the combustion heat exchange device. For example, the inlet pipe 200 includes a control valve that can prevent gas from entering the combustion heat exchange device through the inlet pipe 200.

[0150] In some embodiments of this application, see [reference] Figure 4 , Figure 4A water circuit diagram of a circulation system provided in one embodiment of this application is shown. This application also provides a hot water circulation system, including: an external pipeline, a control element as provided in the above embodiment, a gas water heater 30, a circulating water pump 12, and a water flow sensor 11. The external pipeline and the internal pipeline of the gas water heater 30 constitute a circulation pipeline. The gas water heater 30, the circulating water pump 12, and the water flow sensor 11 are located on the water flow path of the circulation pipeline. The control element is electrically connected to the gas water heater 30, the circulating water pump 12, and the water flow sensor 11, respectively.

[0151] The circulation pipeline includes an inlet pipe 101, a heat exchange pipe 102, an outlet pipe 103, and a terminal pipe. The inlet pipe 101, heat exchange pipe 102, outlet pipe 103, and terminal pipe are connected sequentially. In this embodiment, the hot water circulation system is a zero-cold-water circulation system, whereby the inlet pipe 101, heat exchange pipe 102, outlet pipe 103, and terminal pipe are connected to form the circulation pipeline. The heat exchange pipe 102 is located inside the gas water heater 30, and the liquid inside the heat exchange pipe 102 is heated by the combustion heat exchange device within the gas water heater 30. The circulating water pump 12 provides the kinetic energy for the water flow circulation within the circulation pipeline. The water flow sensor 11 detects the water flow rate within the circulation pipeline.

[0152] Specifically, the hot water circulation system also includes several water appliances and cold water pipes 104. The water appliances include hot water end and cold water end connected to the outlet pipe 103 and the cold water pipe 104 respectively, so that the hot water end and cold water end of the water appliances are connected to the circulation pipeline. After preheating is completed, hot water can be obtained by turning on the water appliances.

[0153] For example, the number of water appliances is at least two, and multiple water appliances are arranged on the circulation pipeline. More specifically, the water appliances include near-end water appliances such as first water appliance n1, second water appliance n2, etc. The water appliances also include the furthest-end water appliance n. f The furthest point is the water heater n f The furthest distance is between the water inlet pipe 101 and the water appliance n at the furthest end. f The distance between the near-end water heater and the inlet pipe 101 is relatively far. The heat exchange tube 102 is connected to the outlet pipe 103 at one end, and the furthest end water heater n... f The hot water end is located near the other end of the outlet pipe 103.

[0154] The circulation system provided in this embodiment includes the control element as described in the above embodiments. Therefore, the beneficial effects that the circulation system in this embodiment can achieve are the same as the beneficial effects that the control element provided in the above embodiments can achieve, and will not be described again here.

[0155] In one specific embodiment, the terminal pipe includes a return pipe 106, which is connected to the furthest water appliance n. fThe hot water end is connected to the inlet pipe 101, so that the inlet pipe 101, heat exchange pipe 102, outlet pipe 103 and return pipe 106 are connected in sequence to form a closed and circulating pipeline.

[0156] In another specific embodiment, combined with Figure 5 , Figure 5 A water circuit diagram of a circulation system provided in another embodiment of this application is shown. The terminal pipe includes a connecting water pipe 105 and a cold water pipe 104 connected to the cold water end of the furthest water appliance. The connecting water pipe 105 connects the hot water end and the cold water end of the furthest water appliance. The inlet pipe 101, heat exchange pipe 102, outlet pipe 103, connecting water pipe 105, and cold water pipe 104 are connected in sequence to form a closed and circulating pipeline.

[0157] Furthermore, the circulation system is also equipped with a one-way valve 13, which restricts the flow direction of water within the closed pipe, ensuring that the water flows in a fixed direction within the closed pipe. In one specific embodiment, the one-way valve 13 is installed on the inlet pipe 101, and the interface between the return pipe 106 and the inlet pipe 101 is located between the one-way valve 13 and the heat exchange tube 102. The one-way valve 13 restricts the liquid in the return pipe 106 from flowing back from the inlet pipe 101 to the inlet end, ensuring that the liquid entering the inlet pipe 101 from the return pipe 106 can only flow towards the heat exchange tube 102. In another specific embodiment, the one-way valve 13 is installed on the connecting water pipe 105, allowing the liquid in the outlet pipe 103 to enter the cold water pipe 104. However, the liquid in the cold water pipe 104 cannot directly enter the outlet pipe 103 to prevent cold water in the cold water pipe 104 from flowing into the outlet pipe 103, which would affect the user experience.

[0158] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0159] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A preheating control method for a gas water heater, characterized in that, include: Multiple preset resistance levels; Different appropriate preheating circulation flow rates correspond to different preset resistance levels; After receiving the first instruction, the resistance of the circulation pipeline is obtained, and the preheating circulation flow rate q4 of the gas water heater is determined and saved based on the resistance of the circulation pipeline. After receiving the second instruction, the circulating water pump (12) is controlled to run according to the preheating circulation flow rate q4, so that the real-time circulation flow rate q5 in the circulation pipeline is equal to the preheating circulation flow rate q4. The step of determining and storing the preheating circulation flow rate q4 of the gas-fired water heater based on the resistance of the circulation pipeline includes: The resistance level of the circulation pipeline is determined based on its resistance; the resistance of the circulation pipeline is characterized by the difference between the maximum circulation flow rate q1 of the circulation pipeline and the preset minimum start-up flow rate q2 of the gas water heater. Select the appropriate preheating circulation flow rate value as the preheating circulation flow rate q4 based on the determined resistance level; The maximum circulation flow rate q1 of the circulation pipeline is obtained in the following way: Upon receiving the first instruction, control the circulating water pump to operate at its rated power; The circulating flow rate of the circulating pipeline is detected as the maximum circulating flow rate q1 of the circulating pipeline.

2. The gas water heater preheating control method according to claim 1, characterized in that, The preset multiple resistance levels include: The preset first level is defined as the difference between the maximum circulation flow q1 and the minimum start flow q2 being greater than or equal to a first threshold. The preset second level is defined as the difference between the maximum circulation flow q1 and the minimum startup flow q2 being greater than or equal to the second threshold and less than the first threshold. The preset third level is when the difference between the maximum circulation flow q1 and the minimum start flow q2 is greater than the third threshold and less than the second threshold; The preset fourth level is defined as the difference between the maximum circulation flow q1 and the minimum start flow q2 being less than or equal to the third threshold. Wherein, the first threshold is greater than the second threshold and the second threshold is greater than the third threshold.

3. The gas water heater preheating control method according to claim 1, characterized in that, The method of determining the appropriate preheating circulation flow rate value corresponding to different preset resistance levels includes: The circulation pipeline is of the first level, and the preset appropriate preheating circulation flow rate corresponding to the first level is the sum of the minimum start-up flow rate q2 and the first predetermined flow rate X1; The circulation pipeline is of the second level, and the preset appropriate preheating circulation flow rate corresponding to the second level is the sum of the minimum start-up flow rate q2 and the second predetermined flow rate X2; The circulation pipeline is of the third level, and the preset appropriate preheating circulation flow rate corresponding to the third level is the sum of the minimum start-up flow rate q2 and the third predetermined flow rate X3; The circulation pipeline is of the fourth level, and the preset appropriate preheating circulation flow rate value corresponding to the fourth level is the maximum circulation flow rate q1; Among them, the first predetermined flow rate X1 is greater than the second predetermined flow rate X2, the second predetermined flow rate X2 is greater than the third predetermined flow rate X3, and the third predetermined flow rate X3 is greater than or equal to 0.

4. The gas water heater preheating control method according to claim 1, characterized in that, The step of controlling the operation of the circulating water pump (12) according to the preheating circulation flow rate q4 after receiving the second instruction includes: When the real-time circulation flow rate q5 is less than the preheating circulation flow rate q4, the circulation pump (12) is controlled to increase the duty cycle at a constant speed to achieve acceleration, and the acceleration frequency is m / 100. Obtain the acceleration time of the circulating water pump (12); When the real-time circulation flow rate q5 is equal to the preheating circulation flow rate q4 or the acceleration time is equal to the preset time, the circulating water pump (12) is controlled to run at a constant speed. Where m is the time required for the duty cycle of the circulating water pump (12) to increase from 0% to 100%, m is greater than or equal to 2 seconds and less than or equal to 4 seconds, and the maximum circulation flow q1 is the circulation flow in the circulation pipeline when the circulating water pump (12) is running at 100% duty cycle.

5. A gas-fired water heater, characterized in that, include: A control element, on which a computer program is stored, wherein when the computer program is executed by the control element, the gas water heater preheating control method as described in any one of claims 1-4 is implemented.

6. The gas water heater according to claim 5, characterized in that, The surface of the gas water heater is provided with a first button and a second button, both of which are electrically connected to the control element. The first button is used to issue the first command; The second button is used to issue a second command.

7. A hot water circulation system, characterized in that, include: The gas water heater (30) as described in claim 5 or 6; An external pipeline, which together with the internal pipeline of the gas water heater (30) constitutes the circulation pipeline; Circulating water pump (12), said circulating water pump (12) is used to form a circulating water flow in said circulating pipeline; and Water flow sensor (11) is used to detect the circulation flow rate of the circulation pipeline.

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