Control method of gas water heater and gas water heater

Abstract

The invention relates to the technical field of hot water supply equipment, and discloses a control method of a gas water heater and the gas water heater. Whether an energy gap exists or not is judged based on the water inlet temperature, the set water outlet temperature and the water flow of the gas water heater and the ignition duration when the gas water heater is started, and the energy gap is used for representing energy needing to be supplemented when the gas water heater is turned off and is started again within the preset duration; if the energy gap exists, the water outlet temperature is set based on the equipment parameters of the gas water heater, and the target flameout duration of delayed closing of the gas valve is determined; and after water of the gas water heater is turned off, the gas water heater is controlled to delay valve closing flameout based on the target delay gas valve closing flameout duration. According to the method, whether the energy gap exists or not is calculated, then the flameout duration of delayed closing of the gas valve possibly needed by the gas water heater is calculated, and the flameout duration of delayed closing of the gas valve is controlled when the energy gap exists, so that energy supplementation is conducted, and the stability of the water outlet temperature after restarting is improved.

Description

Technical Field

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

[0002] Gas water heaters are equipped with a water tank at the connection point between the bypass pipe and the outlet pipe. The water tank can store high-temperature water after bypass, which can reduce temperature drop and make up for the problem of insufficient energy storage in the heat exchanger. The bypass ratio is controlled by controlling the amount of water in the bypass pipe, so that overflow heat is generated in the heat exchange tube. Controlling the storage and release of overflow energy can control the temperature fluctuation during the secondary startup to a certain extent. Due to the limitations of product cost and internal space of gas water heaters, the size of the heat exchanger and water tank is restricted. When facing a few high-power models of water heaters under specific working conditions during the secondary startup, the water outlet temperature may fluctuate to a certain extent due to insufficient energy (i.e., there is an energy gap). Summary of the invention

[0003] The technical problem solved by the present invention is to provide a control method for a gas water heater and a gas water heater, which effectively solves the problem of deviation in outlet water temperature caused by excessive energy gap of the water heater.

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

[0005] A control method for a gas water heater, the method comprising:

[0006] When the gas water heater is ignited and burning stably, judging whether there is an energy gap based on the water inlet temperature, set water outlet temperature, water flow rate and ignition duration of the gas water heater when starting, the energy gap is used to represent the energy that needs to be replenished if the gas water heater is turned off and restarted within a preset time;

[0007] If there is an energy gap, the target delayed closing time of the gas valve is determined based on the equipment parameters of the gas water heater and the set water outlet temperature;

[0008] After the gas water heater is turned off, the gas water heater is controlled to delay closing the gas valve and shut down the gas water heater based on the target delayed closing gas valve and shutting down time.

[0009] Compared with the background technology, the control method of the gas water heater described in the present invention has the following beneficial effects: the method provided in the embodiment of the present invention calculates whether there is an energy gap and then calculates the delayed closing time of the gas valve that may be required for the gas water heater. When there is an energy gap, the delayed closing time of the gas valve is controlled to supplement energy and improve the stability of the water outlet temperature after restarting.

[0010] In one embodiment, the determining whether there is an energy gap based on the water inlet temperature, the set water outlet temperature, the water flow rate, and the ignition time of the gas water heater when starting up includes:

[0011] Determine a first energy based on the water inlet temperature, the set water outlet temperature, the water flow rate, and the ignition duration of the gas water heater when starting, wherein the first energy is used to characterize the energy required from the start of ignition to stable combustion of the gas water heater;

[0012] Determine a second energy based on the current gear position of the bypass valve of the gas water heater, the second energy being used to characterize the difference between the first basic energy corresponding to the current bypass ratio and the second basic energy for heating to the set water outlet temperature when the bypass valve is not opened;

[0013] If the first energy is greater than the second energy, it is determined that an energy gap exists.

[0014] In one embodiment, determining the first energy based on the water inlet temperature, the set water outlet temperature, the water flow rate, and the ignition duration of the gas water heater when starting up includes:

[0015] Calculating the difference between the set water outlet temperature and the water inlet temperature to obtain a first difference;

[0016] A first energy is determined based on a first product of the first difference, the water flow rate, and the ignition duration.

[0017] In one embodiment, determining the second energy based on the current position of the bypass valve of the gas water heater includes:

[0018] Determine a first basic energy corresponding to the set water outlet temperature based on a first preset relationship, where the first preset relationship is used to characterize a mapping relationship between the set water outlet temperature and the first basic energy;

[0019] Determining a second basic energy corresponding to the current gear position of the bypass valve and the set water outlet temperature based on a second preset relationship, wherein the second preset relationship is used to characterize a mapping relationship between the gear position of the bypass valve, the set water outlet temperature, and the second basic energy;

[0020] The second energy is determined based on a difference between the second base energy and the first base energy.

[0021] In one embodiment, the determining of the target delayed closing time of the gas valve based on the equipment parameters of the gas water heater and the set water outlet temperature includes:

[0022] Based on the equipment parameters of the gas water heater, the theoretical required power corresponding to the set water outlet temperature is obtained, and there is a mapping relationship between the equipment parameters and a third preset relationship, and the third preset relationship is used to characterize the mapping relationship between the set water outlet temperature and the theoretical required power;

[0023] Obtain the theoretical delayed closing gas valve flameout time, energy storage upper limit, heating power upper limit and preset correction parameters corresponding to the gas water heater;

[0024] Based on the theoretical required power, the theoretical delayed closing of the gas valve flameout time, the energy storage upper limit, the heating power upper limit and the preset correction parameters, the target delayed closing of the gas valve flameout time is calculated.

[0025] In one embodiment, the target delayed closing gas valve flameout duration is calculated based on the theoretical required power, the theoretical delayed closing gas valve flameout duration, the energy storage upper limit, the heating power upper limit and the preset correction parameter, including:

[0026] Calculating a second product of the theoretical required power and the theoretical delayed closing gas valve flameout time;

[0027] Based on the difference between the second product and the energy storage upper limit, a second difference is obtained;

[0028] A first ratio of the second difference to the upper limit of the heating power is calculated, and the target delayed closing gas valve flameout duration is determined according to a third product of the preset correction parameter and the first ratio.

[0029] In one embodiment, the method further comprises:

[0030] When the gas water heater is in a test state, obtaining the test delay closing gas valve flameout time and the test setting water outlet temperature;

[0031] If the product of the test delayed gas valve closure time and the heating power upper limit meets the required supplementary energy for the test set water outlet temperature, the preset correction parameter is determined based on the ratio of the test delayed gas valve closure time and the theoretical delayed gas valve closure time.

[0032] In one embodiment, the required supplementary energy for setting the outlet water temperature is determined as follows:

[0033] Obtain the test theoretical delay closing gas valve flameout time, the test energy storage upper limit and the test theoretical required power corresponding to the test setting water outlet temperature;

[0034] Calculate the product of the theoretical power required for the test and the theoretical delayed closing time of the gas valve to shut down the test, and determine the required supplementary energy for setting the outlet water temperature of the test based on the product of the theoretical power required for the test and the theoretical delayed closing time of the gas valve to shut down the test and the test energy storage upper limit.

[0035] In one embodiment, the method further comprises:

[0036] If there is no energy gap, after the water supply of the gas water heater is turned off, the gas water heater is controlled to close the gas valve and extinguish the flame.

[0037] A gas water heater comprises a control device, wherein the control device is used to execute any one of the above-mentioned control methods for the gas water heater. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] 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.

[0039] Figure 1 A schematic diagram of a gas water heater according to an embodiment of the present invention;

[0040] Figure 2 A schematic flow chart of a control method for a gas water heater according to an embodiment of the present invention;

[0041] Figure 3 Schematic diagram of a flow chart of a method for controlling a gas water heater according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] Due to the limitation of product cost and internal space of gas water heater, the size of heat exchanger and water tank is restricted. When facing the specific working conditions of a few high-power water heaters during secondary startup, the energy gap may be too large and still cause a certain degree of temperature fluctuation. Based on this, the present invention provides a control method for gas water heater.

[0047] According to an embodiment of the present invention, a gas water heater is provided. Figure 1As 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, a water outlet temperature sensor, and a water tank is arranged at the intersection of the bypass pipe and the water outlet pipe. 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. The bypass valve is a combined valve body composed of a plurality of switch valves connected in parallel. 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 water flow sensor is arranged on the water inlet end of the water inlet pipe, and is used to measure the water flow of the inlet water. The bypass valve adopts a bypass valve, and the bypass ratio can be adjusted as needed. The water inlet temperature sensor is arranged on 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 on 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 located at the outlet end of the outlet pipe to measure the outlet water temperature. The water tank is used for energy storage and water mixing.

[0048] 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 2 is a flow chart of a control method for a gas water heater according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0049] Step S101, when the gas water heater is ignited and burning stably, determine whether there is an energy gap based on the water inlet temperature of the gas water heater, the set water outlet temperature, the water flow rate and the ignition time of the gas water heater when starting.

[0050] Among them, the energy gap is used to represent the energy that needs to be replenished when the gas water heater is turned off and started again within a preset time.

[0051] The energy efficiency of a gas water heater is affected by many factors during operation. When it is ignited and burning stably, it indicates that the gas water heater is in a stable working state. First, several key operating parameters of the gas water heater are collected, including the inlet water temperature, the set outlet water temperature, the water flow rate, and the ignition time of the gas water heater at startup. Among them, the inlet water temperature can be measured by the inlet water temperature sensor, the water flow rate can be measured by the water flow sensor, and the set outlet water temperature can be set by the user, indicating the desired final outlet water temperature. The temperature difference can be determined based on the inlet water temperature and the set outlet water temperature.

[0052] Since there is an ignition process in the gas water heater, there is a heating blank period in the process. The energy required for the heating blank period is calculated based on the temperature difference, water flow and ignition duration. In addition, the energy overflowed during operation under the bypass ratio can be determined based on the difference between the energy after the current bypass ratio is adjusted and the basic energy. The energy required for the heating blank period is compared with the overflowed energy to determine whether there is an energy gap.

[0053] Step S102: If there is an energy gap, the target delayed closing time of the gas valve is determined based on the equipment parameters of the gas water heater and the set water outlet temperature.

[0054] If there is an energy gap, it means that the gas water heater needs to replenish energy after turning off the water and restarting within the preset time. Therefore, when the gas water heater is turned off, the gas valve needs to be closed for a delayed time to avoid insufficient energy when restarting. According to the equipment parameters of the gas water heater, the power required to set the outlet water temperature, the theoretical power required, the theoretical delayed closing of the gas valve, the upper limit of energy storage, and the upper limit of heating power can be determined. Based on these parameters, the target delayed closing of the gas valve can be calculated.

[0055] In some optional implementations, the equipment parameters include the model of the gas water heater. In equipment of different models, there is a corresponding relationship between the set water outlet temperature and the required power, which can be measured through experimental simulation during the equipment design phase.

[0056] Step S103, after the gas water heater is turned off, based on the target delayed closing time of the gas valve, control the gas water heater to delay closing the gas valve to turn off the flame.

[0057] After determining the target delayed closing time of the gas valve, when the valve closing command is received, the gas water heater is controlled to delay, and the valve closing operation is performed after the delay time reaches the target delayed closing time of the gas valve, combustion is stopped, and the system enters the standby state.

[0058] The control method of the gas water heater provided by the embodiment of the present invention includes, when the gas water heater is ignited and the combustion is stable, judging whether there is an energy gap based on the inlet water temperature of the gas water heater, the set outlet water temperature, the water flow rate and the ignition time of the gas water heater at the time of startup, wherein the energy gap is used to characterize the energy that needs to be replenished if the gas water heater is turned off and restarted within a preset time; if there is an energy gap, determining the target delayed closing gas valve flameout time based on the equipment parameters of the gas water heater and the set outlet water temperature; after the gas water heater is turned off, controlling the delayed closing of the gas valve to shut down the gas water heater based on the target delayed closing of the gas valve flameout time. This method calculates whether there is an energy gap and then calculates the delayed closing of the gas valve flameout time that the gas water heater may need, and controls the delayed closing of the gas valve flameout time when there is an energy gap, thereby replenishing energy and improving the stability of the outlet water temperature after restarting.

[0059] 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:

[0060] Step S201, when the gas water heater is ignited and burning stably, determine whether there is an energy gap based on the water inlet temperature of the gas water heater, the set water outlet temperature, the water flow rate, and the ignition time of the gas water heater when starting;

[0061] Specifically, step S201 includes:

[0062] Step S2011, determining the first energy based on the water inlet temperature, the set water outlet temperature, the water flow rate, and the ignition time of the gas water heater when starting.

[0063] The temperature difference is calculated by the water inlet temperature and the set water outlet temperature, and the temperature difference indicates the water temperature that the water heater needs to raise. The first energy is then calculated based on the temperature difference, the water flow rate, and the ignition time of the gas water heater at startup. The first energy is used to characterize the energy required from the start of ignition to stable combustion of the gas water heater.

[0064] In some optional embodiments, the above step S2011 includes: calculating the difference between the set water outlet temperature and the water inlet temperature to obtain a first difference; and determining the first energy based on the first difference, the water flow rate and the first product of the ignition duration.

[0065] Specifically, the first energy = T c ×L×T d , where T c Indicates the difference between the set water outlet temperature and the water inlet temperature, L indicates the water flow rate, T d Indicates the ignition duration.

[0066] Step S2012, determining the second energy based on the current bypass valve position of the gas water heater.

[0067] The second energy is used to characterize the difference between the first basic energy corresponding to the current bypass ratio and the second basic energy heated to the set water outlet temperature when the bypass valve is not opened.

[0068] When the bypass valve is opened, the gas water heater needs to provide more energy to heat the water to ensure that the water temperature after mixing with the cold water reaches the set water outlet temperature. This energy is the first basic energy. Specifically, there is a corresponding relationship between the current bypass valve gear position and the first basic energy, and the first basic energy can be determined according to the current bypass valve gear position.

[0069] The second basic energy represents the energy consumed when the bypass valve is not opened. When the bypass valve is not opened, the set water outlet temperature is the final water outlet temperature of the water heater, and the energy consumed at this time is the second basic energy. Specifically, the second basic energy corresponds to the set water outlet temperature, and the second basic energy can be determined according to the set water outlet temperature.

[0070] In some optional implementations, the above step S2012 includes:

[0071] Step a1, determining a first basic energy corresponding to setting the outlet water temperature based on a first preset relationship.

[0072] The first preset relationship can be stored in the control device in the form of a data table, and the first preset relationship is used to characterize the mapping relationship between the set water outlet temperature and the first basic energy. After determining the set water outlet temperature, the corresponding first basic energy is determined according to the first preset relationship.

[0073] Step a2, determining the current position of the bypass valve and setting the second basic energy corresponding to the outlet water temperature based on the second preset relationship.

[0074] The second preset relationship can be stored in the control device in the form of a data table, and the second preset relationship is used to characterize the mapping relationship between the bypass valve position, the set water outlet temperature, and the second basic energy. After determining the bypass valve position and the set water outlet temperature, the corresponding second basic energy can be determined based on the second preset relationship.

[0075] Step a3: determining the second energy based on the difference between the second basic energy and the first basic energy.

[0076] The difference between the second basic energy and the first basic energy is the second energy. In order to maintain a stable water outlet temperature, the gas water heater needs to increase additional energy consumption. After opening the bypass valve, the gas water heater needs to consume additional energy. This energy is used to heat cold water and compensate for the temperature drop caused by mixing cold water.

[0077] Step S2013: if the first energy is greater than the second energy, it is determined that there is an energy gap.

[0078] The calculated first energy is compared with the second energy. If the first energy is greater than the second energy, it indicates that the energy required by the gas water heater from the start of ignition to stable combustion exceeds the energy that can be provided under the current bypass valve position, so there is an energy gap.

[0079] Step S202: If there is an energy gap, the target delayed closing time of the gas valve is determined based on the equipment parameters of the gas water heater and the set water outlet temperature.

[0080] Specifically, step S202 includes:

[0081] Step S2021, based on the equipment parameters of the gas water heater, obtain the theoretical required power corresponding to the set water outlet temperature.

[0082] Among them, there is a mapping relationship between the device parameter and the third preset relationship, and the third preset relationship is based on data measured in advance and is used to characterize the mapping relationship between the set water outlet temperature and the theoretical required power. The device parameter includes the model of the gas water heater, and the third preset relationship corresponding to the parameter is determined according to the device parameter. The theoretical required power indicates the power required by the water heater to heat the water temperature to the set water outlet temperature under ideal conditions.

[0083] Step S2022, obtaining the theoretical delayed closing gas valve flameout time, energy storage upper limit, heating power upper limit and preset correction parameters corresponding to the gas water heater.

[0084] The theoretical delay in closing the gas valve is based on the design or empirical data of the gas water heater. It is the time from when the gas water heater receives the command to close the gas valve to when the gas valve is actually closed. It is the time that the gas water heater should delay closing the gas valve after the water is turned off. Ideally, there is no energy gap (that is, additional energy is required) or excess energy (that is, energy overflow) when delaying the theoretical delay in closing the gas valve. However, due to differences in the structure and process of each gas water heater, the theoretical delay in closing the gas valve is a theoretical value, and the actual time for closing the gas valve of each gas water heater varies.

[0085] The energy storage limit indicates the maximum heat or energy that the gas water heater can store. If this limit is exceeded, the gas water heater may no longer be able to effectively store more heat.

[0086] The upper limit of heating power indicates the maximum heating power that the gas water heater can provide, indicating the upper limit of the capacity of the gas water heater during the heating process.

[0087] The preset correction parameter is used to adjust the calculation result to more accurately reflect the performance of the water heater in actual use, and the preset correction parameter can be determined based on experimental data.

[0088] Step S2023, based on the theoretical required power, the theoretical delayed closing of the gas valve flameout time, the energy storage upper limit, the heating power upper limit and the preset correction parameters, calculate the target delayed closing of the gas valve flameout time.

[0089] Specifically, the above step S2023 includes:

[0090] Step b1, calculating the second product of the theoretical required power and the theoretical delayed closing time of the gas valve;

[0091] Step b2, obtaining a second difference based on the difference between the second product and the upper limit of energy storage;

[0092] Step b3, calculating a first ratio of the second difference to the upper limit of the heating power, and determining a target delayed closing time of the gas valve according to a third product of a preset correction parameter and the first ratio.

[0093] Target delay closing gas valve flameout time T s The calculation formula is as follows:

[0094] T s =(P L ×T 0 -N s )÷P s ×k

[0095] Among them, P L represents the theoretical power required, T 0 Indicates the theoretical delay in closing the gas valve to shut down the flameout time, N s Represents the upper limit of energy storage, and the second product is P L ×T 0 , the second difference is P L ×T 0 -N s , P s represents the upper limit of heating power, and k represents the preset correction parameter.

[0096] Step S203, after the gas water heater is turned off, based on the target delayed closing time of the gas valve to shut down the gas water heater, control the gas water heater to delay closing the gas valve to shut down the gas water heater.

[0097] For details, please see Figure 1 Step S103 of the illustrated embodiment will not be described in detail here.

[0098] According to an embodiment of the present invention, a control method for a gas water heater is provided. 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 method also includes:

[0099] Step S301, when the gas water heater is in a test state, obtain the test delay closing gas valve flameout time and the test set water outlet temperature.

[0100] Specifically, step S301 includes:

[0101] Step S3011, obtaining the test theoretical delayed closing gas valve flameout time, the test energy storage upper limit and the test theoretical required power corresponding to the test set water outlet temperature.

[0102] The test theory delays the closing of the gas valve to shut down the flameout time based on the water heater design or empirical data. Under the test conditions, how long should the water heater delay closing the gas valve after turning off the water?

[0103] The test storage limit indicates the maximum amount of heat or energy that the water heater can store under the test conditions.

[0104] The theoretical power required for the test means that the theoretical power required to achieve the water outlet temperature under the test conditions is calculated based on the test setting water outlet temperature and the mapping relationship provided by the water heater manufacturer.

[0105] Step S3012, calculate the product of the theoretical power required for the test and the theoretical delayed closing time of the gas valve to shut down, and determine the required supplementary energy for the test to set the water outlet temperature based on the product of the theoretical power required for the test and the theoretical delayed closing time of the gas valve to shut down and the test energy storage upper limit.

[0106] The product of the theoretical power required for the test and the theoretical delay in closing the gas valve indicates the total energy that the water heater can provide during the delay in closing the gas valve without additional energy demand. Based on the difference between the product and the upper limit of the test energy storage, the additional energy required by the water heater during the delay in closing the gas valve is calculated to achieve the test set water outlet temperature.

[0107] Step S302, if the product of the test delayed closing gas valve flameout time and the upper limit of the heating power meets the required supplementary energy for the test set water outlet temperature, the preset correction parameter is determined based on the ratio of the test delayed closing gas valve flameout time and the theoretical delayed closing gas valve flameout time.

[0108] First, determine whether the product of the test delayed gas valve shutdown time and the upper limit of the heating power meets the required supplementary energy for the test set water outlet temperature. This judgment is to confirm whether the water heater can provide sufficient energy to reach the test set water outlet temperature within the test delayed gas valve shutdown time under the maximum heating power.

[0109] If the conditions are met, it indicates that the performance of the water heater under the test conditions is good. At this time, the preset correction parameter can be determined based on the ratio of the test delay closing gas valve flameout time to the theoretical delay closing gas valve flameout time. This ratio reflects the difference between the actual performance and theoretical performance of the water heater under the test conditions. By adjusting the preset correction parameter, the control algorithm of the water heater can more accurately reflect this difference, thereby improving the energy efficiency and user experience of the water heater.

[0110] In some optional embodiments, the above method further comprises: if there is no energy gap, after the gas water heater is turned off, controlling the gas water heater to close the gas valve and extinguish the flame.

[0111] If it is determined that there is no energy gap, it means that after the water is turned off, the heat or energy stored inside the water heater is sufficient to maintain or reach the set water outlet temperature, and there is no need for additional delay in closing the gas valve operation.

[0112] According to an embodiment of the present invention, a gas water heater is provided. The gas water heater includes a control device. The control device is used to execute the control method of the gas water heater of the above embodiment.

[0113] Specifically, the control device includes:

[0114] An energy gap judgment module is used to judge whether there is an energy gap based on the water inlet temperature of the gas water heater, the set water outlet temperature, the water flow rate and the ignition time of the gas water heater when the gas water heater is ignited and combustion is stable. The energy gap is used to characterize the energy that needs to be replenished when the gas water heater is turned off and restarted within a preset time; a delay time calculation module is used to determine the target delayed closing gas valve extinction time based on the equipment parameters of the gas water heater and the set water outlet temperature if there is an energy gap; a control module is used to control the gas water heater to delay closing the gas valve and turn off the flameout based on the target delayed closing gas valve extinction time after the gas water heater is turned off.

[0115] 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.

[0116] 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 ignited and burning stably, judging whether there is an energy gap based on the water inlet temperature, set water outlet temperature, water flow rate and ignition duration of the gas water heater when starting, the energy gap is used to represent the energy that needs to be replenished if the gas water heater is turned off and restarted within a preset time; If there is an energy gap, the target delayed closing time of the gas valve is determined based on the equipment parameters of the gas water heater and the set water outlet temperature; After the gas water heater is turned off, the gas water heater is controlled to delay closing the gas valve and shut down the gas water heater based on the target delayed closing gas valve and shutting down time.

2. The method according to claim 1, characterized in that The determining whether there is an energy gap based on the water inlet temperature, the set water outlet temperature, the water flow rate, and the ignition time of the gas water heater when starting up includes: Determine a first energy based on the water inlet temperature, the set water outlet temperature, the water flow rate, and the ignition duration of the gas water heater when starting, wherein the first energy is used to characterize the energy required from the start of ignition to stable combustion of the gas water heater; Determine a second energy based on the current gear position of the bypass valve of the gas water heater, the second energy being used to characterize the difference between the first basic energy corresponding to the current bypass ratio and the second basic energy for heating to the set water outlet temperature when the bypass valve is not opened; If the first energy is greater than the second energy, it is determined that an energy gap exists.

3. The method according to claim 2, characterized in that The determining of the first energy based on the water inlet temperature, the set water outlet temperature, the water flow rate, and the ignition duration of the gas water heater when starting up includes: Calculating the difference between the set water outlet temperature and the water inlet temperature to obtain a first difference; A first energy is determined based on a first product of the first difference, the water flow rate, and the ignition duration.

4. The method according to claim 2, characterized in that: The determining of the second energy based on the current gear position of the bypass valve of the gas water heater comprises: Determine a first basic energy corresponding to the set water outlet temperature based on a first preset relationship, where the first preset relationship is used to characterize a mapping relationship between the set water outlet temperature and the first basic energy; Determining a second basic energy corresponding to the current gear position of the bypass valve and the set water outlet temperature based on a second preset relationship, wherein the second preset relationship is used to characterize a mapping relationship between the gear position of the bypass valve, the set water outlet temperature, and the second basic energy; The second energy is determined based on a difference between the second base energy and the first base energy.

5. The method according to claim 1, characterized in that The step of determining the target delayed closing time of the gas valve based on the equipment parameters of the gas water heater and the set water outlet temperature includes: Based on the equipment parameters of the gas water heater, the theoretical required power corresponding to the set water outlet temperature is obtained, and there is a mapping relationship between the equipment parameters and a third preset relationship, and the third preset relationship is used to characterize the mapping relationship between the set water outlet temperature and the theoretical required power; Obtain the theoretical delayed closing gas valve flameout time, energy storage upper limit, heating power upper limit and preset correction parameters corresponding to the gas water heater; Based on the theoretical required power, the theoretical delayed closing of the gas valve flameout time, the energy storage upper limit, the heating power upper limit and the preset correction parameters, the target delayed closing of the gas valve flameout time is calculated.

6. The method according to claim 5, characterized in that The target delayed closing gas valve flameout time is calculated based on the theoretical required power, the theoretical delayed closing gas valve flameout time, the energy storage upper limit, the heating power upper limit and the preset correction parameter, including: Calculating a second product of the theoretical required power and the theoretical delayed closing gas valve flameout time; Based on the difference between the second product and the energy storage upper limit, a second difference is obtained; A first ratio of the second difference to the upper limit of the heating power is calculated, and the target delayed closing gas valve flameout duration is determined according to a third product of the preset correction parameter and the first ratio.

7. The method according to claim 5, characterized in that The method further comprises: When the gas water heater is in a test state, obtaining the test delay closing gas valve flameout time and the test setting water outlet temperature; If the product of the test delayed gas valve closure time and the heating power upper limit meets the required supplementary energy for the test set water outlet temperature, the preset correction parameter is determined based on the ratio of the test delayed gas valve closure time and the theoretical delayed gas valve closure time.

8. The method according to claim 7, characterized in that The required supplementary energy for setting the outlet water temperature in the test is determined as follows: Obtain the test theoretical delay closing gas valve flameout time, the test energy storage upper limit and the test theoretical required power corresponding to the test setting water outlet temperature; Calculate the product of the theoretical power required for the test and the theoretical delayed closing time of the gas valve to shut down the test, and determine the required supplementary energy for setting the outlet water temperature of the test based on the product of the theoretical power required for the test and the theoretical delayed closing time of the gas valve to shut down the test and the test energy storage upper limit.

9. The method according to claim 1, characterized in that: The method further comprises: If there is no energy gap, after the gas water heater is turned off, the gas water heater is controlled to close the gas valve and extinguish.

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

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