Control method and control device of gas water heater and gas water heater

Abstract

This application relates to a control method, control device, and gas water heater for a gas water heater. The method includes: acquiring a set temperature; selecting a corresponding target bypass ratio based on the set temperature; acquiring a current bypass ratio; and adjusting the current bypass ratio based on the target bypass ratio. The target bypass ratio is obtained based on the maximum bypass ratio when the inlet water temperature is the lowest at the set temperature and the outlet water temperature of the heat exchange tube does not exceed the upper limit temperature. Since the target bypass ratio is obtained as the maximum bypass ratio when the inlet water temperature is the lowest at the set temperature and the outlet water temperature of the heat exchange tube does not exceed the upper limit temperature, adjusting the current bypass ratio according to the target bypass ratio ensures that the bypass ratio of the gas water heater does not exceed the maximum bypass ratio, reducing vaporization caused by excessively high water temperature in the heat exchange tube.

Description

Technical Field

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

[0002] In the existing technology, gas water heaters often use a bypass mixing thermostatic regulation method to maintain a stable outlet water temperature. The bypass mixing thermostatic regulation is achieved by mixing the hot water heated by the heat exchanger with the cold water in the bypass pipe, and then outputting hot water at the target temperature.

[0003] The bypass mixing constant temperature control scheme in related technologies only considers the stability of the outlet water temperature, but does not consider the water temperature in the heat exchange tube. If the water temperature in the heat exchange tube is too high, vaporization is likely to occur, generating vaporization noise. Summary of the Invention

[0004] Therefore, it is necessary to provide a control method, control device, and gas water heater that can reduce the occurrence of vaporization in gas water heaters, addressing the aforementioned technical problems.

[0005] In a first aspect, this application provides a control method for a gas water heater. The method includes: acquiring a set temperature, selecting a corresponding target bypass ratio based on the set temperature; acquiring a current bypass ratio, and adjusting the current bypass ratio based on the target bypass ratio; wherein the target bypass ratio is obtained based on the maximum bypass ratio when the inlet water temperature is the lowest temperature and the outlet water temperature of the heat exchange tube does not exceed the upper limit temperature at the set temperature.

[0006] In one embodiment, the target bypass ratio is obtained based on the maximum bypass ratio when the inlet water temperature is the lowest temperature and the heat exchange tube outlet water temperature does not exceed the upper limit temperature at the set temperature. This includes: the target bypass ratio is obtained by comparing the maximum bypass ratio when the inlet water temperature is the lowest temperature and the heat exchange tube outlet water temperature does not exceed the upper limit temperature with a preset bypass ratio. If the maximum bypass ratio is greater than the preset bypass ratio, then the preset bypass ratio is used as the target bypass ratio; otherwise, the maximum bypass ratio is used as the target bypass ratio.

[0007] In one embodiment, before the step of selecting the corresponding target bypass ratio according to the set temperature, the method further includes: obtaining the actual outlet water temperature, obtaining a first temperature deviation based on the actual outlet water temperature and the set temperature; obtaining a first preset temperature range, and if the first temperature deviation is within the first preset temperature range, selecting a preset target bypass ratio according to the set temperature.

[0008] In one embodiment, the step of adjusting the current bypass ratio according to the target bypass ratio includes: obtaining a bypass ratio deviation based on the target bypass ratio and the current bypass ratio; obtaining a preset bypass ratio range; and if the bypass ratio deviation exceeds the preset bypass ratio range, adjusting the bypass ratio deviation to the preset bypass ratio range if the first temperature deviation does not exceed the first preset temperature range.

[0009] In one embodiment, before the step of obtaining the actual outlet water temperature, the method further includes: obtaining the inlet water temperature, the set temperature, and the total water flow rate, and determining the load demand accordingly; if the load demand is within a preset load range, adjusting the heating power according to the load demand and calculating the first temperature deviation; if the load demand is outside the preset load range, adjusting the heating power to the maximum power or the minimum power, and adjusting the bypass ratio of the water proportional valve according to the preset target bypass ratio selected based on the set temperature.

[0010] In one embodiment, after the step of adjusting the bypass ratio of the water proportional valve according to the preset target bypass ratio based on the set temperature, the method further includes: obtaining the current heat exchange tube outlet water temperature; if the current heat exchange tube outlet water temperature is greater than the upper limit temperature, then reducing the bypass ratio of the water proportional valve; if the current heat exchange tube outlet water temperature is less than or equal to the upper limit temperature, then maintaining the bypass ratio of the water proportional valve.

[0011] In one embodiment, the method further includes: if the first temperature deviation is outside the first preset temperature range, adjusting the heating power and / or the bypass ratio of the water proportional valve until the first temperature deviation is within the first preset temperature range.

[0012] In one embodiment, before the step of obtaining the actual outlet water temperature and obtaining a first temperature deviation based on the actual outlet water temperature and the set temperature, the method further includes: obtaining the inlet water temperature, the current bypass ratio, and the heat exchange tube outlet water temperature, and using these to determine the calculated outlet water temperature; obtaining the set temperature, and determining a second temperature deviation based on the calculated outlet water temperature and the set temperature; obtaining a second preset temperature range, and if the second temperature deviation is within the second preset temperature range, obtaining the actual outlet water temperature and obtaining the first temperature deviation based on the actual outlet water temperature and the set temperature.

[0013] In one embodiment, after the step of determining the second temperature deviation based on the calculated outlet water temperature and the set temperature, the method further includes: if the second temperature deviation is outside the second preset temperature range, adjusting the bypass ratio of the water proportional valve; after adjusting the bypass ratio of the water proportional valve, obtaining the actual outlet water temperature, and obtaining the first temperature deviation based on the actual outlet water temperature and the set temperature.

[0014] Secondly, this application also provides a control device for a gas water heater. The device includes: a bypass ratio determination module, used to acquire a set temperature and select a corresponding target bypass ratio based on the set temperature; and a bypass ratio adjustment module, used to acquire a current bypass ratio and adjust the current bypass ratio based on the target bypass ratio; wherein the target bypass ratio is obtained based on the maximum bypass ratio when the inlet water temperature is the lowest temperature and the outlet water temperature of the heat exchange tube does not exceed the upper limit temperature at the set temperature.

[0015] Thirdly, this application also provides a gas water heater. The gas water heater includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the above-described method.

[0016] The aforementioned control method, control device, and gas water heater select a target bypass ratio based on the user's set temperature, and then adjust the current bypass ratio according to the target bypass ratio. Since the target bypass ratio is the maximum bypass ratio obtained when the inlet water temperature is at its lowest and the outlet water temperature of the heat exchange tube does not exceed its upper limit at the set temperature, adjusting the current bypass ratio according to the target bypass ratio ensures that the gas water heater's bypass ratio does not exceed the maximum bypass ratio, reducing vaporization caused by excessively high water temperature in the heat exchange tube. Attached Figure Description

[0017] Figure 1 This is an application environment diagram of a control method for a gas water heater in one embodiment.

[0018] Figure 2 This is a flowchart illustrating a control method for a gas water heater in one embodiment;

[0019] Figure 3 This is a schematic diagram of a process for adjusting the bypass ratio based on the actual outlet water temperature in one embodiment.

[0020] Figure 4 This is a flowchart illustrating the process of adjusting the bypass ratio based on a target bypass ratio in one embodiment.

[0021] Figure 5 This is a schematic diagram of a process for adjusting the bypass ratio according to load demand in one embodiment;

[0022] Figure 6 This is a schematic diagram of a process for adjusting the bypass ratio based on the current outlet water temperature of the heat exchanger tube in one embodiment.

[0023] Figure 7 This is a schematic diagram of a process for adjusting the bypass ratio based on the calculated water temperature in one embodiment;

[0024] Figure 8This is a schematic diagram of the process for adjusting the bypass ratio based on the calculated outlet water temperature in another embodiment;

[0025] Figure 9 This is a flowchart illustrating the control method for a gas water heater in another embodiment;

[0026] Figure 10 This is a flowchart illustrating the control method for a gas water heater in yet another embodiment;

[0027] Figure 11 This is a schematic diagram of the control device of a gas water heater in one embodiment. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0029] The control method for gas water heaters provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, the gas water heater includes a heat exchanger 101, a burner 102, a water tank temperature sensor 103, an outlet water temperature sensor 104, and a water proportional valve 105. The water tank temperature sensor 103 is used to detect the outlet water temperature of the heat exchanger 101, the outlet water temperature sensor 104 is used to detect the outlet water temperature of the gas water heater, and the water proportional valve 105 can be a three-way water proportional valve that integrates a water flow sensor and a temperature sensor, used to detect the inlet water flow, the inlet water temperature, and adjust the bypass ratio respectively.

[0030] To address the issue of outlet water temperature fluctuations during the use of gas water heaters (caused by fluctuations in water volume, inlet water temperature, or interruptions during operation), related technologies adjust the water flow rate into the heat exchanger 101 by controlling the bypass ratio of the water proportional valve 105, thereby stabilizing the outlet water temperature. However, when the bypass ratio is adjusted too high, the water flow rate into the bypass pipe increases, while the water flow rate into the heat exchanger 101 decreases. Since the combustion power of the burner 102 remains constant, when the water flow rate into the heat exchanger 101 is too low, the water temperature inside the heat exchanger tubes will exceed the limit, causing vaporization and generating vaporization noise. Simultaneously, the risk of scale buildup on the heat exchanger tubes increases, affecting the lifespan of the water tank.

[0031] Based on this, this application proposes a control method, control device and gas water heater for a gas water heater, which can reduce the vaporization phenomenon in the heat exchange tubes of the heat exchanger 101 caused by overheating of the water.

[0032] In one embodiment, such as Figure 2 As shown, a control method for a gas water heater is provided, which is applied to... Figure 1Taking a gas water heater as an example, the explanation includes the following steps:

[0033] Step S110: Obtain the set temperature and select the corresponding target bypass ratio based on the set temperature.

[0034] Specifically, users can select the desired outlet water temperature through the user interface to obtain the set temperature. After obtaining the set temperature, the corresponding target bypass ratio is selected based on the set temperature. The target bypass ratio is obtained based on the maximum bypass ratio when the inlet water temperature is at its lowest and the outlet water temperature of the heat exchange tube does not exceed the upper limit temperature at that set temperature.

[0035] The maximum bypass ratio is the bypass ratio at which the inlet water temperature is at its lowest setting and the outlet water temperature of the heat exchanger tubes does not exceed the upper limit temperature. The lowest temperature can be the lowest inlet water temperature typically found in a household, such as 0 degrees Celsius. The upper limit temperature is the maximum permissible temperature at which the heat exchanger tubes just do not vaporize, such as 65 degrees Celsius. Under normal circumstances, the inlet water temperature is higher than the lowest temperature. In this case, the bypass ratio required for the heat exchanger tubes to exceed the upper limit temperature is also greater than the maximum bypass ratio. By limiting the bypass ratio to not exceed the maximum bypass ratio, it can be ensured that the outlet water temperature of the heat exchanger tubes does not exceed the upper limit temperature.

[0036] The upper limit temperature can be obtained through prior experimental testing. For example, it can be obtained through a vaporization noise experiment by continuously increasing the combustion power of burner 102 and recording the heat exchanger outlet water temperature. When vaporization noise occurs, the highest temperature before the occurrence of vaporization noise can be taken as the upper limit temperature. Alternatively, multiple experiments can be conducted, and the lowest of the multiple highest temperatures before the occurrence of vaporization noise can be determined as the upper limit temperature. The maximum bypass ratio can be calculated using the following formula:

[0037] Pmax = 1 - (Ts - Tj) / (Th - Tj)

[0038] Where Pmax is the maximum bypass ratio of the bypass pipe, Ts is the set temperature of the gas water heater, Tj is the inlet water temperature of the gas water heater, and Th is the upper limit temperature of the heat exchange tube.

[0039] For example, with the upper limit temperature of the heat exchanger tube at 66.67 degrees Celsius and the inlet water temperature at 0 degrees Celsius, the following table shows the maximum bypass ratio calculated in one embodiment:

[0040]

[0041] Step S120: Obtain the current bypass ratio and adjust the current bypass ratio according to the target bypass ratio.

[0042] Specifically, after obtaining the current bypass ratio of the water proportional valve 105, the current bypass ratio is adjusted according to the relationship between the target bypass ratio and the current bypass ratio. For example, if the current bypass ratio is greater than the target bypass ratio, the current bypass ratio is reduced to the target bypass ratio; if the current bypass ratio is equal to the target bypass ratio, the current bypass ratio is maintained; if the current bypass ratio is less than the target bypass ratio, the current bypass ratio is increased to the target bypass ratio.

[0043] The control method for the aforementioned gas water heater selects a target bypass ratio based on the user's set temperature, and then adjusts the current bypass ratio accordingly. Since the target bypass ratio is the maximum bypass ratio obtained when the inlet water temperature is at its minimum and the outlet water temperature of the heat exchanger tube does not exceed its upper limit at the set temperature, adjusting the current bypass ratio based on the target ratio ensures that the gas water heater's bypass ratio does not exceed the maximum bypass ratio. Adjusting the bypass ratio to a smaller value reduces vaporization caused by excessively high water temperatures within the heat exchanger tube.

[0044] Furthermore, excessively high outlet water temperatures in the heat exchanger can lead to scale buildup on the heat exchange tubes, reducing the lifespan of the gas water heater. Therefore, the upper limit temperature should also take scale buildup into account. For example, the upper limit temperature obtained from the vaporization noise experiment can be used in a durability test simulating user conditions. The gas water heater can operate at this upper limit temperature for 1 minute and then stop for 1 minute, repeating this cycle 60,000 times. If, after the durability test, the gas water heater's performance still meets national standards, then this upper limit temperature can be used as the final upper limit temperature. This can further reduce the risk of scale buildup in the heat exchanger and increase the lifespan of the gas water heater.

[0045] In one embodiment, the target bypass ratio is obtained based on the maximum bypass ratio when the inlet water temperature is the lowest at the set temperature and the outlet water temperature of the heat exchanger tube does not exceed the upper limit temperature, including:

[0046] The target bypass ratio is obtained by comparing the maximum bypass ratio with the preset bypass ratio when the inlet water temperature is the lowest temperature and the outlet water temperature of the heat exchange tube does not exceed the upper limit temperature at the set temperature. If the maximum bypass ratio is greater than the preset bypass ratio, the preset bypass ratio is used as the target bypass ratio; otherwise, the maximum bypass ratio is used as the target bypass ratio.

[0047] For example, the preset bypass ratio can be set to 50%. When the maximum bypass ratio is greater than 50%, 50% is used as the target bypass ratio so that subsequent bypass ratio adjustments have a certain range of upward adjustment. When the maximum bypass ratio is less than or equal to 50%, since its upward adjustment range is not large, the maximum bypass ratio is directly set as the target bypass ratio.

[0048] Specifically, the gas water heater can directly store a table showing the correspondence between the set temperature and the target bypass ratio, allowing users to directly select the corresponding target bypass ratio based on the set temperature. Alternatively, the gas water heater can store the minimum inlet water temperature, the upper limit temperature of the heat exchange tube, and the preset bypass ratio. The gas water heater calculates the maximum bypass ratio based on the user-input set temperature, the stored minimum temperature, and the stored upper limit temperature, and then obtains the target bypass ratio based on the comparison between the maximum bypass ratio and the preset bypass ratio.

[0049] In one embodiment, such as Figure 3 As shown, before the step of selecting the corresponding target bypass ratio based on the set temperature in step S110, the control method for the gas water heater further includes:

[0050] Step S130: Obtain the actual water temperature and obtain the first temperature deviation based on the actual water temperature and the set temperature.

[0051] Specifically, the actual outlet water temperature can be detected in real time by the outlet water temperature sensor 104. After obtaining the actual outlet water temperature, the difference between the actual outlet water temperature and the set temperature can be used as the first temperature deviation. It can be understood that the sign of the first temperature deviation can be used to determine the relationship between the actual outlet water temperature and the set temperature.

[0052] Step S140: Obtain the first preset temperature range. If the first temperature deviation is within the first preset temperature range, select the preset target bypass ratio according to the set temperature.

[0053] Specifically, after obtaining the first temperature deviation, a first preset temperature range is then acquired. This first preset temperature range is a pre-set range used to determine whether the actual outlet water temperature reaches the set temperature and whether the fluctuation is small. For example, the first preset temperature range can be [-1, 1], meaning that when the fluctuation of the difference between the actual outlet water temperature and the set temperature does not exceed 1 degree Celsius, the step of selecting the preset target bypass ratio based on the set temperature in step S110 continues. It can be understood that in this embodiment, when the difference between the actual outlet water temperature and the set temperature of the gas water heater is within the first preset temperature range, it indicates that the gas water heater is currently in a constant temperature stable state.

[0054] In one embodiment, the control method for a gas water heater further includes: if the first temperature deviation is outside the first preset temperature range, adjusting the heating power and / or the bypass ratio of the water proportional valve until the first temperature deviation is within the first preset temperature range.

[0055] Specifically, when the first temperature deviation is outside the first preset temperature range, it indicates a significant discrepancy between the actual outlet water temperature and the set temperature. In this case, to ensure the actual outlet water temperature reaches the set temperature, it is necessary to adjust the heating power and / or the bypass ratio of the water proportional valve to control the first temperature deviation within the first preset temperature range. Understandably, after each adjustment of the heating power and / or the bypass ratio of the water proportional valve, it is necessary to continue acquiring the actual outlet water temperature until the first temperature deviation between the actual outlet water temperature and the set temperature is within the first preset temperature range. Then, based on the target bypass ratio determined by the set temperature, the current bypass ratio is adjusted to prevent the heat exchanger tube outlet water temperature from exceeding the upper limit temperature. For example, if the actual outlet water temperature is lower than the set temperature, the bypass ratio of the water proportional valve and the heating power can be increased to quickly bring the actual outlet water temperature to the set temperature, achieving a stable constant temperature state. Then, the current bypass ratio is adjusted based on the target bypass ratio.

[0056] In one embodiment, such as Figure 4 As shown, step S120, the step of adjusting the current bypass ratio according to the target bypass ratio, includes:

[0057] Step S121: Obtain the bypass ratio deviation based on the target bypass ratio and the current bypass ratio.

[0058] Specifically, after obtaining the current bypass ratio, the difference between the current bypass ratio and the preset target bypass ratio is calculated to obtain the bypass ratio deviation. It can be understood that the sign of the bypass ratio deviation indicates the relationship between the target bypass ratio and the current bypass ratio.

[0059] Step S122: Obtain the preset bypass ratio range. If the bypass ratio deviation exceeds the preset bypass ratio range, then if the first temperature deviation does not exceed the first preset temperature range, adjust the bypass ratio deviation to the preset bypass ratio range.

[0060] Specifically, after obtaining the bypass ratio deviation, a preset bypass ratio range is also acquired. This preset bypass ratio range is a user-defined allowable deviation range. For example, the preset bypass ratio range could be [0, 1%]. Adjusting the bypass ratio deviation to this preset range ensures that the current bypass ratio is less than the target bypass ratio by less than 1%. Simultaneously, adjusting the bypass ratio deviation to the preset bypass ratio range while ensuring the first temperature deviation does not exceed the first preset temperature range is to prevent fluctuations in the outlet water temperature. For example, the bypass ratio can be adjusted using a fixed adjustment speed, which can be determined experimentally. Under this fixed adjustment speed, the first temperature deviation will not exceed the first preset temperature range.

[0061] In one embodiment, such as Figure 5As shown, before obtaining the actual outlet water temperature in step S130, the control method for the gas water heater further includes:

[0062] Step S150: Obtain the inlet water temperature, set temperature, and total water flow rate, and use these to determine the load demand.

[0063] Specifically, let the inlet water temperature be Tj, the set temperature be Ts, and the total water flow rate be L. At this time, the load demand W = (Ts - Tj) * L.

[0064] Step S160: If the load demand is within the preset load range, adjust the heating power according to the load demand and calculate the first temperature deviation.

[0065] Specifically, the preset load range is the range of loads that the gas water heater can provide, that is, the minimum to maximum load that the gas water heater can provide. If the load demand is within the preset load range, it means that the gas water heater can meet the load requirements. At this time, the actual outlet water temperature can be adjusted to the set temperature by adjusting the heating power. Therefore, the heating power adjustment is completed by calculating the first temperature deviation.

[0066] In step S170, if the load demand is outside the preset load range, the heating power is adjusted to the maximum or minimum power, and the bypass ratio of the water proportional valve is adjusted according to the preset target bypass ratio selected based on the set temperature.

[0067] Specifically, when the load demand is outside the preset load range, i.e. the load demand is greater than the maximum load or less than the minimum load, the heating power is directly adjusted to the maximum power or minimum power. Then, the bypass ratio of the water proportional valve 105 is adjusted according to the preset target bypass ratio based on the set temperature, so that the actual outlet water temperature is as close as possible to the set temperature while the outlet water temperature of the heat exchange tube does not exceed the upper limit temperature.

[0068] In one embodiment, such as Figure 6 As shown, in step S170, after adjusting the bypass ratio of the water proportional valve according to the preset target bypass ratio based on the set temperature, the following steps are also included:

[0069] Step S171: Obtain the current outlet water temperature of the heat exchanger tube;

[0070] Step S172: If the current outlet water temperature of the heat exchange tube is greater than the upper limit temperature, then reduce the bypass ratio of the water proportional valve.

[0071] Step S173: If the current outlet water temperature of the heat exchange tube is less than or equal to the upper limit temperature, then maintain the bypass ratio of the water proportional valve.

[0072] Specifically, when the load demand is outside the preset load range, during the adjustment of the bypass ratio of the water proportional valve 105, the current bypass ratio may be adjusted to a level greater than the maximum bypass ratio. In this case, it is necessary to obtain the current heat exchange tube outlet water temperature in real time through the water tank temperature sensor 103 to monitor the heat exchange tube outlet water temperature in real time. When the current heat exchange tube outlet water temperature is greater than the upper limit temperature, it is necessary to reduce the bypass ratio of the water proportional valve 105 to increase the water flow into the heat exchanger 101; when the current heat exchange tube outlet water temperature is less than or equal to the upper limit temperature, it is necessary to maintain the bypass ratio of the water proportional valve 105. Since the target bypass ratio is obtained through the maximum bypass ratio, and the maximum bypass ratio is calculated based on the set temperature, the calculation assumes that the power corresponding to the set temperature can meet the user's load requirements. However, if the power corresponding to the set temperature cannot meet the user's load requirements, the target bypass ratio may be problematic, causing the outlet water temperature of the heat exchange tube to be higher than the upper limit temperature. Therefore, by comparing the outlet water temperature of the heat exchange tube with the upper limit temperature, the vaporization phenomenon caused by overheating of the heat exchange tube in the heat exchanger 101 can be further reduced.

[0073] In one embodiment, such as Figure 7 As shown, before the step of obtaining the actual outlet water temperature and calculating the first temperature deviation based on the actual outlet water temperature and the set temperature in step S130, the control method for the gas water heater further includes:

[0074] Step S131: Obtain the inlet water temperature, the current bypass ratio, and the heat exchange tube outlet water temperature, and use these to determine the calculated outlet water temperature.

[0075] Specifically, after the water heater starts working, the inlet water temperature, the current bypass ratio, and the outlet water temperature of the heat exchange tube are first obtained. Let the inlet water temperature be Tj, the current bypass ratio be Pd, and the outlet water temperature of the heat exchange tube be Th. At this time, the outlet water temperature Tc is calculated as (Th-Tj)(1-Pd)+Tj.

[0076] Step S132: Obtain the set temperature and determine the second temperature deviation based on the calculated water temperature and the set temperature.

[0077] Specifically, after obtaining the set temperature, the second temperature deviation is determined based on the difference between the calculated water temperature and the set temperature. In other words, the sign of the second temperature deviation indicates the relationship between the calculated water temperature and the set temperature.

[0078] Step S133: Obtain the second preset temperature range. If the second temperature deviation is within the second preset temperature range, obtain the actual water outlet temperature and obtain the first temperature deviation based on the actual water outlet temperature and the set temperature.

[0079] Specifically, the second preset temperature range is a range set by the user in advance, used to determine whether the error between the calculated outlet water temperature and the set temperature meets the requirements under the current bypass ratio. If the second temperature deviation is within the second preset temperature range, it means that the calculated outlet water temperature meets the requirements of the set temperature under the current bypass ratio. At this time, step S130 is then executed to obtain the actual outlet water temperature and obtain the first temperature deviation based on the actual outlet water temperature and the set temperature.

[0080] In one embodiment, such as Figure 8 As shown, after determining the second temperature deviation based on the calculated outlet water temperature and the set temperature in step S132, the control method for the gas water heater further includes:

[0081] Step S134: If the second temperature deviation is outside the second preset temperature range, adjust the bypass ratio of the water proportional valve.

[0082] Specifically, if the second temperature deviation is outside the second preset temperature range, it indicates that the calculated outlet water temperature deviates significantly from the set temperature under the current bypass ratio. In this case, the bypass ratio of the water proportional valve 105 needs to be adjusted. For example, if the calculated outlet water temperature is greater than the set temperature and the second temperature deviation is outside the second preset range, the bypass ratio of the water proportional valve 105 needs to be increased.

[0083] Step S135: After adjusting the bypass ratio of the water proportional valve, obtain the actual outlet water temperature, and obtain the first temperature deviation based on the actual outlet water temperature and the set temperature.

[0084] Specifically, after adjusting the bypass ratio of the water proportional valve 105, step S130 is executed to obtain the actual outlet water temperature. The first temperature deviation is obtained based on the actual outlet water temperature and the set temperature to determine whether the actual outlet water temperature meets the set temperature.

[0085] The control method of the gas water heater of this application is described in detail below with a specific embodiment, such as... Figure 9As shown, when the gas water heater starts working, it first obtains the inlet water temperature Tj, the set temperature Ts, and the total water flow L, and calculates the load demand W based on these. When the load demand is within the preset load range, the heating power is adjusted according to the load demand, and the actual outlet water temperature Tcs is obtained after adjustment to calculate the first temperature deviation. When the first temperature deviation is within the first preset range, the target bypass ratio Pm is determined based on the set temperature Ts while keeping the heating power unchanged. If the current bypass ratio deviation exceeds the preset bypass ratio range, the bypass ratio deviation is adjusted to the preset bypass ratio range if the first temperature deviation does not exceed the first preset temperature range. When the first temperature deviation is outside the first preset range, the first temperature deviation can be adjusted until it is within the first preset temperature range by adjusting the heating power and / or the bypass ratio of the water proportional valve. When the gas water heater starts working, it can simultaneously obtain the inlet water temperature Tj, the current bypass ratio Pd, and the heat exchange tube outlet water temperature Th, and use these to determine and calculate the outlet water temperature Tc. At the same time, it calculates the second temperature deviation based on the set temperature Ts. If the second temperature deviation is within the second preset temperature range, the actual outlet water temperature is obtained, and the first temperature deviation is obtained based on the actual outlet water temperature and the set temperature. If the second temperature deviation is outside the second preset temperature range, the actual outlet water temperature is obtained after adjusting the bypass ratio of the water proportional valve, and subsequent steps are executed.

[0086] like Figure 10 As shown, when the gas water heater starts working, if the calculated load demand W is outside the preset load range, the heating power is adjusted to the maximum or minimum power, and the preset target bypass ratio Pm is selected according to the set temperature to adjust the bypass ratio of the water proportional valve. After adjusting the bypass ratio, the current heat exchange tube outlet water temperature Th is obtained. If the current heat exchange tube outlet water temperature Th is greater than the upper limit temperature Thmax, the bypass ratio of the water proportional valve is reduced until the requirement is met; if the current heat exchange tube outlet water temperature Th is less than or equal to the upper limit temperature Thmax, the bypass ratio P of the water proportional valve is maintained.

[0087] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated 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 steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0088] Based on the same inventive concept, this application also provides a control device for a gas water heater to implement the control method for the gas water heater described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more embodiments of the control device for a gas water heater provided below can be found in the limitations of the control method for the gas water heater described above, and will not be repeated here.

[0089] In one embodiment, such as Figure 11 As shown, a control device for a gas water heater is provided, including: a bypass ratio determination module 210 and a bypass ratio adjustment module 220, wherein: the bypass ratio determination module 210 is used to obtain a set temperature and select a corresponding target bypass ratio according to the set temperature; the bypass ratio adjustment module 220 is used to obtain the current bypass ratio and adjust the current bypass ratio according to the target bypass ratio; wherein, the target bypass ratio is obtained based on the maximum bypass ratio when the inlet water temperature is the lowest temperature and the outlet water temperature of the heat exchange tube does not exceed the upper limit temperature at the set temperature.

[0090] In one embodiment, the target bypass ratio is obtained based on the maximum bypass ratio when the inlet water temperature is the lowest temperature at the set temperature and the outlet water temperature of the heat exchange tube does not exceed the upper limit temperature. This includes: the target bypass ratio is obtained by comparing the maximum bypass ratio when the inlet water temperature is the lowest temperature at the set temperature and the outlet water temperature of the heat exchange tube does not exceed the upper limit temperature with a preset bypass ratio. If the maximum bypass ratio is greater than the preset bypass ratio, the preset bypass ratio is used as the target bypass ratio; otherwise, the maximum bypass ratio is used as the target bypass ratio.

[0091] In one embodiment, the control device for a gas water heater further includes: an actual outlet water temperature response module, configured to acquire the actual outlet water temperature, obtain a first temperature deviation based on the actual outlet water temperature and a set temperature; acquire a first preset temperature range, and if the first temperature deviation is within the first preset temperature range, select a preset target bypass ratio based on the set temperature.

[0092] In one embodiment, the bypass ratio adjustment module 220 is further configured to obtain the bypass ratio deviation based on the target bypass ratio and the current bypass ratio; obtain a preset bypass ratio range; and if the bypass ratio deviation exceeds the preset bypass ratio range, adjust the bypass ratio deviation to the preset bypass ratio range if the first temperature deviation does not exceed the first preset temperature range.

[0093] In one embodiment, the control device of the gas water heater further includes: a load response module, used to acquire the inlet water temperature, the set temperature and the total water flow, and thereby determine the load demand; if the load demand is within the preset load range, the heating power is adjusted according to the load demand and a first temperature deviation is calculated; if the load demand is outside the preset load range, the heating power is adjusted to the maximum power or the minimum power, and the bypass ratio of the water proportional valve is adjusted according to the preset target bypass ratio selected based on the set temperature.

[0094] In one embodiment, the control device for the gas water heater further includes: a heat exchange tube outlet water temperature response module, used to obtain the current heat exchange tube outlet water temperature; if the current heat exchange tube outlet water temperature is greater than the upper limit temperature, then reduce the bypass ratio of the water proportional valve; if the current heat exchange tube outlet water temperature is less than or equal to the upper limit temperature, then maintain the bypass ratio of the water proportional valve.

[0095] In one embodiment, the actual outlet water temperature response module is further configured to adjust the heating power and / or the bypass ratio of the water proportional valve until the first temperature deviation is within the first preset temperature range if the first temperature deviation is outside the first preset temperature range.

[0096] In one embodiment, the control device for a gas water heater further includes: a water temperature calculation response module, used to acquire the inlet water temperature, the current bypass ratio, and the heat exchange tube outlet water temperature, and thereby determine the calculated water temperature; acquire a set temperature, and determine a second temperature deviation based on the calculated water temperature and the set temperature; acquire a second preset temperature range, and if the second temperature deviation is within the second preset temperature range, acquire the actual water temperature, and obtain a first temperature deviation based on the actual water temperature and the set temperature.

[0097] In one embodiment, the water temperature response module is further configured to adjust the bypass ratio of the water proportional valve if the second temperature deviation is outside the second preset temperature range; after adjusting the bypass ratio of the water proportional valve, the actual water temperature is obtained, and the first temperature deviation is obtained based on the actual water temperature and the set temperature.

[0098] As described above, the various modules in the control device of the gas water heater can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0099] In one embodiment, a gas water heater is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0100] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in the above-described method embodiments.

[0101] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0102] 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.

[0103] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this 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 application should be determined by the appended claims.

Claims

1. A control method for a gas water heater, characterized in that, The method includes: Obtain the inlet water temperature, set temperature, and total water flow rate, and use these to determine the load demand; If the load demand is within the preset load range, the heating power is adjusted according to the load demand and the first temperature deviation is calculated; wherein, the first temperature deviation is obtained by acquiring the actual outlet water temperature and the set temperature; Obtain a first preset temperature range; if the first temperature deviation is within the first preset temperature range, select a preset target bypass ratio based on the set temperature. If the load demand is outside the preset load range, the heating power is adjusted to the maximum or minimum power, and a preset target bypass ratio is selected according to the set temperature. Obtain the current bypass ratio, and adjust the current bypass ratio according to the target bypass ratio; The target bypass ratio is obtained based on the maximum bypass ratio when the inlet water temperature is the lowest temperature and the outlet water temperature of the heat exchange tube does not exceed the upper limit temperature at the set temperature.

2. The method according to claim 1, characterized in that, The target bypass ratio is obtained based on the maximum bypass ratio when the inlet water temperature is the lowest at the set temperature and the outlet water temperature of the heat exchange tube does not exceed the upper limit temperature, including: The target bypass ratio is obtained by comparing the maximum bypass ratio and the preset bypass ratio when the inlet water temperature is the lowest temperature and the outlet water temperature of the heat exchange tube does not exceed the upper limit temperature at the set temperature. If the maximum bypass ratio is greater than the preset bypass ratio, the preset bypass ratio is used as the target bypass ratio; otherwise, the maximum bypass ratio is used as the target bypass ratio.

3. The method according to claim 1, characterized in that, The step of adjusting the current bypass ratio according to the target bypass ratio includes: The bypass ratio deviation is obtained based on the target bypass ratio and the current bypass ratio; Obtain a preset bypass ratio range. If the bypass ratio deviation exceeds the preset bypass ratio range, then, if the first temperature deviation does not exceed the first preset temperature range, adjust the bypass ratio deviation to the preset bypass ratio range.

4. The method according to claim 1, characterized in that, After the step of selecting a preset target bypass ratio and adjusting the bypass ratio of the water proportional valve according to the set temperature, the method further includes: Get the current outlet water temperature of the heat exchanger tube; If the current outlet water temperature of the heat exchange tube is greater than the upper limit temperature, then reduce the bypass ratio of the water proportional valve; If the current outlet water temperature of the heat exchanger tube is less than or equal to the upper limit temperature, then the bypass ratio of the water proportional valve is maintained.

5. The method according to claim 1, characterized in that, The method further includes: If the first temperature deviation is outside the first preset temperature range, adjust the heating power and / or the bypass ratio of the water proportional valve until the first temperature deviation is within the first preset temperature range.

6. The method according to claim 1, characterized in that, Before the step of obtaining the actual outlet water temperature and obtaining the first temperature deviation based on the actual outlet water temperature and the set temperature, the method further includes: Obtain the inlet water temperature, the current bypass ratio, and the heat exchange tube outlet water temperature, and use these to determine the calculated outlet water temperature; Obtain the set temperature, and determine the second temperature deviation based on the calculated outlet water temperature and the set temperature; Obtain a second preset temperature range. If the second temperature deviation is within the second preset temperature range, obtain the actual water outlet temperature. Based on the actual water outlet temperature and the set temperature, obtain the first temperature deviation.

7. The method according to claim 6, characterized in that, After the step of determining the second temperature deviation based on the calculated outlet water temperature and the set temperature, the method further includes: If the second temperature deviation is outside the second preset temperature range, adjust the bypass ratio of the water proportional valve; After adjusting the bypass ratio of the water proportional valve, the actual outlet water temperature is obtained, and the first temperature deviation is obtained based on the actual outlet water temperature and the set temperature.

8. A control device for a gas water heater, characterized in that, The device includes: The load response module is used to acquire the inlet water temperature, the set temperature, and the total water flow rate, and to determine the load demand based on these. If the load demand is within the preset load range, the heating power is adjusted according to the load demand and a first temperature deviation is calculated. If the load demand is outside the preset load range, the heating power is adjusted to the maximum or minimum power, and a preset target bypass ratio is selected according to the set temperature. The actual outlet water temperature response module is used to obtain the actual outlet water temperature, and to obtain the first temperature deviation based on the actual outlet water temperature and the set temperature; to obtain a first preset temperature range; and if the first temperature deviation is within the first preset temperature range, to select a preset target bypass ratio based on the set temperature. The bypass ratio adjustment module is used to obtain the current bypass ratio and adjust the current bypass ratio according to the target bypass ratio; The target bypass ratio is obtained based on the maximum bypass ratio when the inlet water temperature is the lowest temperature and the outlet water temperature of the heat exchange tube does not exceed the upper limit temperature at the set temperature.

9. A gas water heater, characterized in that, The device includes a memory and a processor, the memory storing a computer program, characterized in that the processor executes the computer program to implement the steps of the control method for the gas water heater according to any one of claims 1 to 7.

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