Gas water heater control method and gas water heater

Abstract

The invention relates to the technical field of hot water supply equipment, and discloses a gas water heater control method and a gas water heater, the gas water heater control method comprises the following steps: when the gas water heater is restarted within a preset time or a preset temperature change range, determining a first heating power based on a set temperature, a water flow rate and a water inlet temperature of the gas water heater; determining a target bypass ratio corresponding to the first heating power; comparing the current bypass ratio with a target bypass ratio, and determining target heating power based on a comparison result; and the current bypass ratio is reduced to be a preset bypass ratio, and the gas water heater is controlled to work based on the target heating power. According to the method, the current bypass ratio is compared with the target bypass ratio to be used for judging whether the current situation meets the energy storage requirement or not, and therefore the actually-needed heating power can be determined. According to the comparison result of the current bypass ratio and the target bypass ratio, the target heating power is determined, the heating power can be adaptively adjusted, and therefore water outlet temperature fluctuation caused by insufficient energy storage is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of hot water supply equipment, and in particular to a gas water heater control method and a gas water heater. Background Art

[0002] The gas water heater generates additional energy in the heat exchange tube by installing a bypass pipe connecting the water inlet and outlet and adjusting the water flow ratio in the pipe (i.e., the bypass ratio). The accumulation and release process of these energies can be used to alleviate the temperature fluctuations during the second startup, thereby solving the common problem of unstable startup temperature. However, when the set temperature is relatively high, the water outlet temperature of the water tank is high, causing the water tank to produce vaporization noise, accelerating the formation of scale, and affecting the heat exchange efficiency and life of the water tank. Therefore, it is necessary to limit the water outlet temperature of the water tank. The water outlet temperature of the water tank is usually limited by reducing the bypass ratio. When the bypass ratio is relatively small, the water heater may have insufficient energy storage, which will cause large temperature fluctuations during the second startup, affecting the user experience. Summary of the invention

[0003] The technical problem solved by the present invention is to provide a gas water heater control method and a gas water heater, which effectively solves the problem of insufficient energy storage caused by setting a relatively high temperature after restarting.

[0004] The first technical problem mentioned above is solved by the following technical solution:

[0005] When the gas water heater is started again within a preset time or within a preset temperature change range, a first heating power is determined based on the set temperature, water flow rate and inlet water temperature of the gas water heater; a target bypass ratio corresponding to the first heating power is determined; a current bypass ratio is compared with the target bypass ratio, and the target heating power is determined based on the comparison result; the current bypass ratio is reduced to a preset bypass ratio, and the gas water heater is controlled to operate based on the target heating power.

[0006] Compared with the background technology, the control method of the gas water heater described in the present invention has the following beneficial effects: after the gas water heater is restarted, the current corresponding first heating power is determined according to the current set temperature, and then the corresponding target bypass ratio is determined according to the first heating power, and the current bypass ratio is compared with the target bypass ratio to determine whether the current situation meets the energy storage demand, so that the actually required heating power (i.e., the target heating power) can be determined. The target heating power is determined according to the comparison result between the current bypass ratio and the target bypass ratio, and the heating power can be adaptively adjusted to avoid the fluctuation of the outlet water temperature caused by insufficient energy storage.

[0007] In one embodiment, determining the first heating power based on the set temperature, water flow rate and water inlet temperature of the gas water heater includes:

[0008] Calculating the difference between the set temperature and the water inlet temperature;

[0009] The first heating power is determined based on a product of the difference and the water flow rate.

[0010] In one embodiment, determining the target bypass ratio corresponding to the first heating power includes:

[0011] The target bypass ratio corresponding to the first heating power is obtained by querying a pre-stored relationship table based on the first heating power, wherein the pre-stored relationship table is used to characterize the corresponding relationship between power and bypass ratio.

[0012] In one embodiment, determining the target heating power based on the comparison result includes:

[0013] Whether compensatory heating is required is determined based on the comparison result, and the target heating power is determined according to the determination result.

[0014] In one embodiment, judging whether compensatory heating is required based on the comparison result, and determining the target heating power according to the judgment result, includes:

[0015] If the comparison result indicates that the current bypass ratio is greater than or equal to the target bypass ratio, then the determination result indicates that no compensatory heating is required;

[0016] The first heating power is determined as the target heating power.

[0017] In one embodiment, judging whether compensatory heating is required based on the comparison result, and determining the target heating power according to the judgment result, includes:

[0018] If the comparison result indicates that the current bypass ratio is less than the target bypass ratio, then the determination result indicates that compensatory heating is required;

[0019] The target heating power is determined based on a correction parameter and the first heating power, wherein the correction parameter is determined based on a device parameter of the gas water heater.

[0020] In one embodiment, the correction parameter includes a first correction parameter and a second correction parameter, and determining the target heating power based on the correction parameter and the first heating power includes:

[0021] calculating a difference between the current bypass ratio and the target bypass ratio;

[0022] Determine a first correction parameter by multiplying the calculated difference by a preset coefficient;

[0023] The product of the first correction parameter and the first heating power is calculated to obtain a first product, and the target heating power is determined based on the sum of the first product and the second correction parameter.

[0024] In one embodiment, after controlling the gas water heater to operate based on the target heating power, the method further includes:

[0025] After the current bypass ratio is adjusted to the preset bypass ratio, obtaining a second water tank temperature and a second water outlet temperature;

[0026] If the second water tank temperature and the second water outlet temperature fluctuate within a preset range, the bypass ratio of the gas water heater is adjusted to the target bypass ratio.

[0027] The above second technical problem is solved by the following technical solution:

[0028] A gas water heater, characterized in that the gas water heater comprises a control device, and the control device is used to execute any of the methods described above.

[0029] In one embodiment, the control device comprises:

[0030] A first power determination module, configured to determine a first heating power based on a set temperature, a water flow rate and a water inlet temperature of the gas water heater when the gas water heater is restarted within a preset time or within a preset temperature variation range;

[0031] a target bypass ratio determination module, configured to determine a target bypass ratio corresponding to the first heating power;

[0032] a target power determination module, configured to compare the current bypass ratio with the target bypass ratio, and determine the target heating power based on the comparison result;

[0033] The water heater control module is used to reduce the current bypass ratio to a preset bypass ratio and control the gas water heater to operate based on the target heating power.

[0034] Compared with the background technology, the gas water heater of the present invention has the following beneficial effects: after the gas water heater is restarted, the current corresponding first heating power is determined according to the current set temperature, and then the corresponding target bypass ratio is determined according to the first heating power, and the current bypass ratio is compared with the target bypass ratio to determine whether the current situation meets the energy storage demand, so as to determine the actually required heating power (i.e., the target heating power). The target heating power is determined according to the comparison result between the current bypass ratio and the target bypass ratio, and the heating power can be adaptively adjusted to avoid the fluctuation of the outlet water temperature caused by insufficient energy storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A schematic diagram of a gas water heater according to an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of a gas water heater according to an embodiment of the present invention;

[0038] Figure 3 A schematic flow chart of a control method for a gas water heater according to an embodiment of the present invention;

[0039] Figure 4 A schematic flow chart of a control method for a gas water heater according to an embodiment of the present invention;

[0040] Figure 5 Schematic diagram of a control device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0042] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0043] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0044] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0045] A bypass pipe is set between the water inlet and outlet pipes of the gas water heater. By adjusting the amount of water in the bypass pipe, that is, adjusting the bypass ratio, the energy overflow in the heat exchange tube can be controlled. The bypass ratio is the ratio of the water volume in the bypass pipe to the total water volume. When the bypass ratio is relatively large, more water will pass through the bypass pipe, bypassing the heat exchanger, so the energy in the heat exchanger may overflow and the water outlet temperature of the water tank will increase.

[0046] When using a gas water heater, the user can set the outlet water temperature of the gas water heater. When the outlet water temperature is set high, the outlet water temperature of the water tank will also be relatively high. The increase in the outlet water temperature of the water tank is likely to cause vaporization noise inside the water tank. On the other hand, high-temperature water may accelerate the formation of scale, which in turn affects the heat exchange efficiency and life of the water tank. In order to solve this problem, it is necessary to limit the outlet water temperature of the water tank, usually by reducing the bypass ratio. Reducing the bypass ratio means reducing the amount of water passing through the bypass pipe, thereby increasing the amount of water passing through the main heat exchange area. This can improve the heat exchange efficiency, transfer more heat to the water, and reduce the overflow of energy. The problem that follows is that when the water heater is restarted in a short time, due to the limited heat energy stored inside the water heater, if the bypass ratio is too small, it means that the amount of water passing through the heat exchange area increases, and more heat energy is required to heat the water. However, due to insufficient energy storage, the water heater may not be able to provide enough heat energy in a short time, resulting in a drop in water temperature, that is, large temperature fluctuations.

[0047] According to an embodiment of the present invention, on the one hand, a gas water heater is provided, such as Figure 1 As shown, the gas water heater includes a heat exchanger, a bypass valve, a water flow sensor, a water inlet temperature sensor, a water tank temperature sensor and a water outlet temperature sensor. Among them, the water inlet end of the heat exchanger is provided with a water inlet pipe, the water outlet end of the heat exchanger is provided with a water outlet pipe, and the heat exchanger is provided with a heat exchange pipe. The bypass valve is arranged on the bypass pipe, and the bypass pipe is connected with the water inlet pipe and the water outlet pipe respectively. In some optional embodiments, the bypass valve can adopt a combined valve body composed of a plurality of switch valves in parallel, and the bypass valve can be provided with a plurality of gears for adjusting the bypass ratio, and each gear corresponds to a different bypass ratio. The bypass valve can also adopt the form of a water proportional valve, which can directly adjust the size of the bypass ratio. The water flow sensor is arranged at the water inlet end of the water inlet pipe, and is used to measure the water flow of the water inlet. The water inlet temperature sensor is arranged at the water inlet end of the water inlet pipe, and is used to measure the water inlet temperature of the water inlet. The water tank temperature sensor is arranged at the water outlet end of the heat exchanger, and is used to measure the water outlet temperature of the heat exchange pipe. The outlet water temperature sensor is arranged at the outlet end of the outlet water pipe and is used to measure the outlet water temperature.

[0048] In some optional embodiments, such as Figure 2 As shown, a water mixing tank can also be provided at the intersection of the bypass pipe and the water outlet pipe, and the water mixing tank can be used for energy storage and water mixing.

[0049] According to an embodiment of the present invention, a control method for a gas water heater is provided, which can be used for the above-mentioned gas water heater. Figure 3 is a flow chart of a control method for a gas water heater according to an embodiment of the present invention. Figure 3 As shown, the process includes the following steps:

[0050] Step S101, when the gas water heater is restarted within a preset time or within a preset temperature variation range, a first heating power is determined based on a set temperature, a water flow rate and an inlet water temperature of the gas water heater.

[0051] This embodiment is applied to the scenario where the gas water heater is restarted within a short time or within a temperature change range, specifically, the situation where the gas water heater is originally in a stable working state and is restarted within a preset time or within a preset temperature change range after the water is turned off. The preset time is a time length that is preset according to actual needs and taking into account the parameters of the gas water heater itself. Specifically, if the measured start time of the current gas water heater is within the preset time from the last shut-off time, it means that the current restart scenario applied by this embodiment. In addition, it is also possible to judge whether it is restarted according to the temperature, and the temperature change can consider the change of the water tank temperature or / and the outlet water temperature. Exemplarily, taking the water tank temperature as an example of temperature change, the water tank temperature refers to the outlet water temperature of the heat exchanger, which can be measured by the water tank temperature sensor. After the gas water heater is turned off for the last time, the water tank temperature measured at that time will be recorded. After the gas water heater is turned on again, the current water tank temperature is measured by the water tank temperature sensor. If the temperature difference between the water tank temperature recorded when it is turned off and the current water tank temperature is within the preset temperature difference, it means that the gas water heater is restarted within the preset temperature change range.

[0052] After judgment, if the gas water heater is started again within the preset time or within the preset temperature change range, the first heating power is calculated according to the set temperature, water flow and water inlet temperature of the gas water heater. The first heating power is the power required to heat the water in the heat exchanger to reach the set temperature. The set temperature is the expected water outlet temperature, which can be set by the user on the control panel of the gas water heater. The water flow can be measured by a water flow sensor, and the water inlet temperature can be measured by a water inlet temperature sensor.

[0053] Step S102, determining a target bypass ratio corresponding to a first heating power.

[0054] The target bypass ratio indicates the bypass ratio that the bypass valve needs to adjust when the heat exchanger reaches the first heating power. There is a certain correspondence between the first heating power and the target bypass ratio, which can be stored in the controller of the gas water heater in advance. After the first heating power is calculated, the target bypass ratio corresponding to the first heating power is queried according to the stored correspondence.

[0055] In some optional embodiments, different heating power ranges have corresponding target bypass ratios, and the corresponding target bypass ratio can be determined according to the range of the first heating power.

[0056] Step S103, comparing the current bypass ratio with the target bypass ratio, and determining the target heating power based on the comparison result.

[0057] After determining the target bypass ratio, the current bypass ratio is compared with the target bypass ratio to determine whether the current bypass ratio requirement is met. If it is met, it means that the current bypass ratio can meet the heating requirement. If it is not met, it means that the current bypass ratio may be too small. If the current bypass ratio is used, insufficient energy storage may occur. The corresponding target heating power is determined according to different comparison results. For different situations, the target heating power can be equal to the first heating power, or supplementary power can be added on the basis of the first heating power.

[0058] Step S104, reducing the current bypass ratio to a preset bypass ratio, and controlling the gas water heater to operate based on the target heating power.

[0059] While determining the target heating power, the current bypass ratio will be adjusted to reduce it to a preset value, i.e., the preset bypass ratio. The preset bypass ratio is a value determined based on long-term operating efficiency and application requirements. In this embodiment, the preset bypass ratio is 0, and reducing the current bypass ratio to 0 can maximize the release of stored energy. When the target bypass ratio requirement of the first heating power is not met, the water temperature can still be made to meet the conditions through compensatory heating, breaking through the maximum power limit.

[0060] While reducing the current bypass ratio to a preset bypass ratio, the gas water heater is controlled to operate based on the target heating power.

[0061] The control method of the gas water heater provided in the embodiment of the present invention includes determining a first heating power based on the set temperature, water flow rate and water inlet temperature of the gas water heater when the gas water heater is restarted within a preset time or within a preset temperature change range; determining a target bypass ratio corresponding to the first heating power; comparing the current bypass ratio with the target bypass ratio, and determining the target heating power based on the comparison result; reducing the current bypass ratio to a preset bypass ratio, and controlling the gas water heater to operate based on the target heating power. In this method, the current bypass ratio is compared with the target bypass ratio to determine whether the current situation meets the energy storage demand, so that the actually required heating power (i.e., the target heating power) can be determined. The target heating power is determined based on the comparison result between the current bypass ratio and the target bypass ratio, and the heating power can be adaptively adjusted to avoid fluctuations in the outlet water temperature caused by insufficient energy storage.

[0062] According to an embodiment of the present invention, a control method for a gas water heater is provided, which can be used for the above-mentioned gas water heater, and the method comprises the following steps:

[0063] Step S201, when the gas water heater is restarted within a preset time or within a preset temperature variation range, a first heating power is determined based on a set temperature, a water flow rate and an inlet water temperature of the gas water heater.

[0064] Specifically, the first heating power is determined based on the set temperature, water flow rate and water inlet temperature of the gas water heater in the above step S201, including:

[0065] Step S2011, calculating the difference between the set temperature and the inlet water temperature;

[0066] Step S2012, determining the first heating power based on the product of the difference and the water flow rate.

[0067] Assuming the first heating power is W, the first heating power is calculated according to the following formula:

[0068] W=(T m -T j )×L

[0069] Where W represents the first heating power, T m Indicates the set temperature, T j represents the inlet water temperature, and L represents the water flow rate.

[0070] The set temperature can be set by the user, indicating the desired final water outlet temperature, the water inlet temperature can be measured by the water inlet temperature sensor, and the water flow rate can be measured by the water flow rate sensor.

[0071] In the heat exchange process, heat is transferred from a high-temperature object to a low-temperature object. This transfer process requires a certain driving force, namely the temperature difference. The greater the temperature difference, the greater the driving force for heat transfer. Considering the temperature difference and water flow together, the temperature difference provides the driving force for heat transfer, while the water flow determines the rate of heat transfer. Therefore, the product of the temperature difference and the water flow can be regarded as the power of heat transfer.

[0072] Step S202, determining a target bypass ratio corresponding to the first heating power.

[0073] Specifically, the above step S202 includes: querying a pre-stored relationship table based on the first heating power to obtain a target bypass ratio corresponding to the first heating power, wherein the pre-stored relationship table is used to represent the corresponding relationship between power and bypass ratio.

[0074] The pre-stored relationship table stores the correspondence between the first heating power and the target bypass ratio. The correspondence between the first heating power and the target bypass ratio can be stored in the pre-stored relationship table in a one-to-one correspondence between the power and the bypass ratio, or in a one-to-one correspondence between the power range and the bypass ratio, or in a one-to-one correspondence between the power range and the bypass valve gear position. The specific relationship is not limited. The correspondence between the first heating power and the target bypass ratio is obtained by pre-testing.

[0075] As an example, the one-to-one correspondence between the power range and the bypass valve gear position in the pre-stored relationship table is used for explanation. The bypass valve of the gas water heater can be set to multiple gears, each gear has a corresponding fixed bypass ratio, and the power is divided into multiple ranges, each range has a corresponding bypass valve gear position. It can be understood that the relationship between the power range, bypass valve gear position and bypass ratio is stored in the pre-stored relationship table. For example, when the bypass valve is in the first gear, the corresponding bypass ratio is 20%, and the corresponding power range is 0-150; when the bypass valve is in the second gear, the corresponding bypass ratio is 30%, and the corresponding power range is 150-250.

[0076] Step S203, comparing the current bypass ratio with the target bypass ratio, and determining the target heating power based on the comparison result.

[0077] For details, please see Figure 1 Step S103 of the illustrated embodiment will not be described in detail here.

[0078] Step S204, reducing the current bypass ratio to a preset bypass ratio, and controlling the gas water heater to operate based on the target heating power.

[0079] For details, please see Figure 1 Step S104 of the illustrated embodiment will not be described in detail here.

[0080] The control method for the gas water heater provided in the embodiment of the present invention can determine the first heating power suitable for the current situation according to the set temperature and water flow calculation, and determine the corresponding target bypass ratio by setting the corresponding relationship between the first heating power and the target bypass ratio, so as to facilitate the subsequent further determination of the target heating power.

[0081] According to an embodiment of the present invention, a control method for a gas water heater is provided, which can be used for the above-mentioned gas water heater, and the method comprises the following steps:

[0082] Step S301, when the gas water heater is restarted within a preset time or within a preset temperature variation range, a first heating power is determined based on a set temperature, a water flow rate and an inlet water temperature of the gas water heater.

[0083] For details, please see Figure 1 Step S101 of the illustrated embodiment will not be described in detail here.

[0084] Step S302, determining a target bypass ratio corresponding to the first heating power.

[0085] For details, please see Figure 1 Step S102 of the illustrated embodiment will not be described in detail here.

[0086] Step S303, comparing the current bypass ratio with the target bypass ratio, and determining the target heating power based on the comparison result.

[0087] Specifically, the above step S303 includes: judging whether compensatory heating is needed based on the comparison result, and determining the target heating power according to the judgment result.

[0088] The comparison results include that the current bypass ratio is less than the target bypass ratio, and the current bypass ratio is greater than or equal to the target bypass ratio. Compensation heating means that additional heating power is needed to supplement the energy storage so that the desired set temperature is finally reached. If it is determined that compensation heating is required, the target heating power is determined according to the judgment result. The target heating power can be calculated according to the set calculation formula and existing parameters, or it can have a certain corresponding relationship with the existing parameters, and can be directly determined by looking up the table, and there is no specific limitation.

[0089] Furthermore, the above method comprises:

[0090] Step S3031, if the comparison result indicates that the current bypass ratio is greater than or equal to the target bypass ratio, then the judgment result indicates that no compensatory heating is required;

[0091] Step S3032: determine the first heating power as the target heating power.

[0092] If the current bypass ratio is equal to the target bypass ratio, it means that the current bypass ratio can enable the gas water heater to reach the required heating power, that is, the energy storage is sufficient, and there is no need for compensatory heating, and the first heating power can be used as the target heating power.

[0093] Step S3033, if the comparison result indicates that the current bypass ratio is less than the target bypass ratio, then the judgment result indicates that compensatory heating is required;

[0094] Step S3034, determining the target heating power based on the correction parameter and the first heating power, wherein the correction parameter is determined based on the equipment parameter of the gas water heater.

[0095] If the comparison result shows that the current bypass ratio is less than the target bypass ratio, it means that the current bypass setting has not achieved the ideal condition, and it is necessary to compensate by adjusting the heating power. After determining that compensatory heating is required, the system will calculate the target heating power based on the correction parameters and the first heating power. The correction parameters are determined based on the specific equipment parameters of the gas water heater (such as water heater capacity, thermal efficiency, water flow rate, etc.). The role of the correction parameters is to provide an adjustment factor for adjusting the heating power based on the difference between the current state and the target state. The target heating power is the final calculated heating power value, which is used to drive the water heater to operate in the desired manner to get closer to or reach the ideal state represented by the target bypass ratio.

[0096] In some optional implementations, the above step S3034 includes:

[0097] Step a1, calculating the difference between the current bypass ratio and the target bypass ratio;

[0098] Step a2, determining a first correction parameter by multiplying the calculated difference by a preset coefficient;

[0099] Step a3, calculating the product of the first correction parameter and the first heating power to obtain a first product, and determining the target heating power based on the sum of the first product and the second correction parameter.

[0100] The target heating power is calculated according to the following formula:

[0101] W b =W×A(target bypass ratio-current bypass ratio)+B

[0102] Among them, W b represents the target heating power, W represents the first heating power, A represents the preset coefficient, A (target bypass ratio-current bypass ratio) represents the first correction parameter, and B represents the second correction parameter.

[0103] The preset coefficient and the second correction parameter are obtained through testing and are fixed values.

[0104] Step S304, reducing the current bypass ratio to a preset bypass ratio, and controlling the gas water heater to operate based on the target heating power.

[0105] For details, please see Figure 1 Step S104 of the illustrated embodiment will not be described in detail here.

[0106] According to an embodiment of the present invention, a control method for a gas water heater is provided, which can be used for the above-mentioned gas water heater, and the method comprises the following steps:

[0107] Step S401, after the current bypass ratio is adjusted to a preset bypass ratio, obtaining a second water tank temperature and a second outlet water temperature;

[0108] Step S402: If the second water tank temperature and the second outlet water temperature fluctuate within a preset range, the bypass ratio of the gas water heater is adjusted to a target bypass ratio.

[0109] After the gas water heater operates based on the target heating power and the preset bypass ratio, when the outlet water temperature of the heat exchanger (i.e., the second water tank temperature) and the outlet water temperature of the water outlet pipe (the second outlet water temperature) are in a stable state, the bypass ratio is adjusted back, that is, the bypass ratio is adjusted from the preset bypass ratio to the target bypass ratio. Specifically, after obtaining the second water tank temperature and the second outlet water temperature, it can be determined whether they fluctuate within the preset range. If they fluctuate within the preset range, it indicates that they are in a stable state.

[0110] According to an embodiment of the present invention, a specific control method for a gas water heater is provided, which can be used for the above-mentioned gas water heater. Figure 4 As shown, when the gas water heater is working stably and the water is turned off, if it is started again within a certain period of time or temperature drop, it is judged whether the bypass ratio meets the target requirement, that is, whether the current bypass ratio reaches the target bypass ratio. The calculation method of the target bypass ratio is as described in the control method of the gas water heater in the above embodiment, which will not be repeated here. If the target requirement is met, the current bypass ratio is reduced to 0, and the water is operated according to the first heating power; if the target requirement is not met, compensation heating is required, and the compensation heating method is as described above. After the gas water heater is working stably, the bypass ratio is controlled to call back the energy storage.

[0111] According to an embodiment of the present invention, a gas water heater is provided, the gas water heater comprising a control device for executing the above-mentioned control method of the gas water heater, such as Figure 5 As shown, the control device includes: a first power determination module, which is used to determine the first heating power based on the set temperature, water flow rate and inlet water temperature of the gas water heater when the gas water heater is restarted within a preset time or within a preset temperature change range; a target bypass ratio determination module, which is used to determine the target bypass ratio corresponding to the first heating power; a target power determination module, which is used to compare the current bypass ratio with the target bypass ratio, and determine the target heating power based on the comparison result; a water heater control module, which is used to reduce the current bypass ratio to a preset bypass ratio, and control the gas water heater to operate based on the target heating power.

[0112] The further functional description of each of the above modules is the same as that of the above corresponding embodiments and will not be repeated here.

[0113] The control device in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0114] In the specific contents of the above-mentioned specific implementation methods, the various technical features can be combined in any non-contradictory manner. In order to make the description concise, not all possible combinations of the above-mentioned technical features 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.

[0115] The specific contents of the above specific embodiments only express several embodiments of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A control method for a gas water heater, characterized in that: The method comprises: When the gas water heater is restarted within a preset time or within a preset temperature variation range, a first heating power is determined based on a set temperature, a water flow rate, and an inlet water temperature of the gas water heater; determining a target bypass ratio corresponding to the first heating power; comparing the current bypass ratio with the target bypass ratio, and determining the target heating power based on the comparison result; The current bypass ratio is reduced to a preset bypass ratio, and the gas water heater is controlled to operate based on the target heating power.

2. The method according to claim 1, characterized in that The determining the first heating power based on the set temperature, water flow rate and water inlet temperature of the gas water heater comprises: Calculating the difference between the set temperature and the water inlet temperature; The first heating power is determined based on a product of the difference and the water flow rate.

3. The method according to claim 1, characterized in that The determining a target bypass ratio corresponding to the first heating power includes: The target bypass ratio corresponding to the first heating power is obtained by querying a pre-stored relationship table based on the first heating power, wherein the pre-stored relationship table is used to characterize the corresponding relationship between power and bypass ratio.

4. The method according to claim 1, characterized in that: The step of determining the target heating power based on the comparison result comprises: Whether compensatory heating is required is determined based on the comparison result, and the target heating power is determined according to the determination result.

5. The method according to claim 4, characterized in that The determining whether compensatory heating is required based on the comparison result, and determining the target heating power according to the determination result, comprises: If the comparison result indicates that the current bypass ratio is greater than or equal to the target bypass ratio, then the determination result indicates that no compensatory heating is required; The first heating power is determined as the target heating power.

6. The method according to claim 4, characterized in that The determining whether compensatory heating is required based on the comparison result, and determining the target heating power according to the determination result, comprises: If the comparison result indicates that the current bypass ratio is less than the target bypass ratio, then the determination result indicates that compensatory heating is required; The target heating power is determined based on a correction parameter and the first heating power, wherein the correction parameter is determined based on a device parameter of the gas water heater.

7. The method according to claim 6, characterized in that The correction parameter includes a first correction parameter and a second correction parameter, and determining the target heating power based on the correction parameter and the first heating power includes: calculating a difference between the current bypass ratio and the target bypass ratio; Determine a first correction parameter by multiplying the calculated difference by a preset coefficient; The product of the first correction parameter and the first heating power is calculated to obtain a first product, and the target heating power is determined based on the sum of the first product and the second correction parameter.

8. The method according to claim 1, characterized in that: After controlling the gas water heater to operate based on the target heating power, the method further includes: After the current bypass ratio is adjusted to the preset bypass ratio, obtaining a second water tank temperature and a second water outlet temperature; If the second water tank temperature and the second water outlet temperature fluctuate within a preset range, the bypass ratio of the gas water heater is adjusted to the target bypass ratio.

9. A gas water heater, characterized in that: The gas water heater comprises a control device, which is used to execute the method according to any one of claims 1 to 8.

10. The gas water heater according to claim 9, characterized in that: The control device comprises: A first power determination module, configured to determine a first heating power based on a set temperature, a water flow rate and a water inlet temperature of the gas water heater when the gas water heater is restarted within a preset time or within a preset temperature variation range; a target bypass ratio determination module, configured to determine a target bypass ratio corresponding to the first heating power; a target power determination module, configured to compare the current bypass ratio with the target bypass ratio, and determine the target heating power based on the comparison result; The water heater control module is used to reduce the current bypass ratio to a preset bypass ratio and control the gas water heater to operate based on the target heating power.

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