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. Target output heat is obtained, and the target output heat is compared with the minimum output heat of the gas water heater; if the target output heat is smaller than the minimum output heat, the gas water heater is adjusted to be in a preset working state; the first outlet water temperature output by the gas water heater and the second outlet water temperature output by the heat exchanger are obtained; and the working state of the gas water heater is adjusted based on the size relation between the first water outlet temperature and the target water outlet temperature and the size relation between the second water outlet temperature and the target water outlet temperature. Therefore, the output power of the gas water heater is maintained above the minimum output power, meanwhile, the outlet water temperature of the gas water heater is adjusted by adjusting the bypass ratio of the bypass valve, the outlet water temperature meets the water use requirement of a user, frequent starting and stopping of the gas water heater can be avoided, the stability of the outlet water temperature is guaranteed, and the water use experience of the user is improved.

Description

Technical Field

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

[0002] When using a gas water heater in a situation where the ambient temperature is relatively high, the inlet water temperature of the gas water heater is relatively high. Even when the gas water heater operates at the lowest load, the outlet water temperature will be too high, resulting in the gas water heater being unable to meet the user's demand for the outlet water temperature and the user having a poor water use experience. Summary of the Invention

[0003] The first technical problem solved by the present invention is to provide a control method for a gas water heater, which effectively solves the problem that the gas water heater cannot meet the user's demand for the outlet water temperature and the user has a poor water use experience.

[0004] The second technical problem solved by the present invention is to provide a gas water heater, which effectively solves the problem that the gas water heater cannot meet the user's demand for the outlet water temperature and the user has a poor water use experience.

[0005] The above first technical problem is solved by the following technical solutions:

[0006] A control method for a gas water heater, the gas water heater includes an inlet pipe, an outlet pipe, a heat exchanger, and a bypass valve. The inlet pipe, the heat exchanger, and the outlet pipe are connected in sequence, and the bypass valve is connected between the inlet pipe and the outlet pipe. The method includes:

[0007] Obtain the target output heat, and compare the target output heat with the minimum output heat of the gas water heater;

[0008] If the target output heat is less than the minimum output heat, adjust the gas water heater to a preset working state;

[0009] Obtain the first outlet water temperature output by the gas water heater and the second outlet water temperature output by the heat exchanger;

[0010] Based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature, and the magnitude relationship between the second outlet water temperature and the target outlet water temperature, adjust the working state of the gas water heater. The working state includes the bypass ratio of the bypass valve and the output power of the gas water heater.

[0011] Compared with the background art, the control method of the gas water heater of the present invention has the following beneficial effects: when the target output heat of the gas water heater is less than the minimum output heat, the gas water heater is adjusted to a preset working state, and the working state of the gas water heater is adjusted according to the magnitude relationship between the first outlet water temperature and the target outlet water temperature and the magnitude relationship between the second outlet water temperature and the target outlet water temperature. Thus, when the target output heat required by the user is less than the minimum output heat that the gas water heater can provide, the output power of the gas water heater is maintained above the minimum output power. At the same time, the outlet water temperature of the gas water heater is adjusted by adjusting the bypass ratio of the bypass valve, so that the outlet water temperature meets the user's water use requirements, and the gas water heater can be prevented from frequently starting and stopping, ensuring the stability of the outlet water temperature and improving the user's water use experience.

[0012] In one embodiment, adjusting the gas water heater to the preset working state includes:

[0013] Adjusting the bypass ratio of the bypass valve to a first preset bypass ratio;

[0014] Adjusting the output power of the gas water heater to a preset output power; the preset output power is greater than or equal to the minimum output power of the gas water heater.

[0015] In one embodiment, adjusting the working state of the gas water heater based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature and the magnitude relationship between the second outlet water temperature and the target outlet water temperature includes:

[0016] Adjusting the bypass ratio of the bypass valve based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature;

[0017] Adjusting the output power of the gas water heater based on the magnitude relationship between the second outlet water temperature and the target outlet water temperature.

[0018] In one embodiment, adjusting the bypass ratio of the bypass valve based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature includes:

[0019] If the first outlet water temperature is greater than the target outlet water temperature, increasing the bypass ratio;

[0020] If the first outlet water temperature is less than the target outlet water temperature, decreasing the bypass ratio.

[0021] In one embodiment, adjusting the output power of the gas water heater based on the magnitude relationship between the second outlet water temperature and the target outlet water temperature includes:

[0022] If the difference between the second outlet water temperature and the target outlet water temperature is greater than a preset temperature difference, adjusting the output power of the gas water heater to zero to turn off the combustion of the gas water heater.

[0023] In one embodiment, after adjusting the output power of the gas water heater to zero to turn off the combustion of the gas water heater, it further includes:

[0024] If the bypass ratio of the bypass valve reaches the first preset bypass ratio, adjust the output power of the gas water heater to the preset output power to turn on the combustion of the gas water heater.

[0025] In one embodiment, the method further includes:

[0026] If the bypass ratio of the adjusted bypass valve reaches the second preset bypass ratio, adjust the output power of the gas water heater to zero to turn off the combustion of the gas water heater.

[0027] In one embodiment, obtaining the target output heat includes:

[0028] Obtain the target outlet water temperature, the current inlet water temperature, and the current water flow rate;

[0029] Based on the target outlet water temperature, the current inlet water temperature, and the current water flow rate, determine the target output heat.

[0030] In one embodiment, the method further includes:

[0031] If the target output heat is greater than or equal to the minimum output heat, adjust the bypass ratio to the first preset bypass ratio;

[0032] Based on the target output heat, adjust the output power of the gas water heater.

[0033] The above second technical problem is solved by the following technical solution:

[0034] A gas water heater includes an inlet pipe, an outlet pipe, a heat exchanger, a bypass valve, and a controller;

[0035] The inlet pipe, the heat exchanger, and the outlet pipe are connected in sequence, and the bypass valve is connected between the inlet pipe and the outlet pipe; the controller is used to execute the control method of the gas water heater described in any one of the above. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 It is a schematic structural diagram of a gas water heater according to an embodiment of the present invention;

[0038] Figure 2 It is a schematic flow chart of a control method for a gas water heater according to an embodiment of the present invention;

[0039] Figure 3 It is a schematic flow chart of adjusting the working state of the gas water heater in the control method of the gas water heater according to an embodiment of the present invention. Detailed implementation manners

[0040] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0041] In the description of the present application, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0042] In the description of the present 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 may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0043] When using a gas water heater in a situation where the ambient temperature is relatively high, the inlet water temperature of the gas water heater is high. Even when the gas water heater operates at the lowest load, the outlet water temperature will be too high, resulting in the gas water heater being unable to meet the user's demand for the outlet water temperature and the user having a poor water-using experience. In related technologies, usually a sectional valve is added to reduce the number of burners in use, thereby reducing the output load of the gas water heater; or, the heat exchange efficiency at the minimum load of the gas water heater is reduced to reduce the minimum output power of the gas water heater; for the above methods, restricted by the design and working number of the burners themselves, the output power of a single burner will also reach 3 kW and cannot meet the load demand below 3 kW. Or, an electric heating structure is added, and only the electric heating is used when the required load is less than the output load of the gas water heater, but such a method will increase the structural complexity of the gas water heater; if a mixing valve is added and the user uses the mixing valve to manually mix cold water, although the structural complexity can be reduced, it requires the user to manually adjust, affecting the user's water-using experience.

[0044] Based on this, an embodiment of the present invention provides a control method for a gas water heater, which obtains a target output heat quantity and compares the target output heat quantity with the minimum output heat quantity of the gas water heater; if the target output heat quantity is less than the minimum output heat quantity, the gas water heater is adjusted to a preset working state; the first outlet water temperature output by the gas water heater and the second outlet water temperature output by the heat exchanger are obtained; based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature and the magnitude relationship between the second outlet water temperature and the target outlet water temperature, the working state of the gas water heater is adjusted; the working state includes the bypass ratio of the bypass valve and the output power of the gas water heater. Thus, when the target output heat quantity of the gas water heater is less than the minimum output heat quantity, the gas water heater is adjusted to the preset working state, and the working state of the gas water heater is adjusted through the magnitude relationship between the first outlet water temperature and the target outlet water temperature and the magnitude relationship between the second outlet water temperature and the target outlet water temperature. Therefore, when the target output heat quantity required by the user is less than the minimum output heat quantity that the gas water heater can provide, the output power of the gas water heater is maintained above the minimum output power, and at the same time, the outlet water temperature of the gas water heater is adjusted by adjusting the bypass ratio of the bypass valve, so that the outlet water temperature meets the user's water-using requirements, and the frequent start and stop of the gas water heater can be avoided, the stability of the outlet water temperature is ensured, and the user's water-using experience is improved.

[0045] The following combines Figures 1 to 3 , to describe the embodiments of the present invention.

[0046] According to an embodiment of the present invention, on the one hand, a gas water heater is provided, which includes an inlet pipe, an outlet pipe, a heat exchanger, a bypass valve, and a controller; the inlet pipe, the heat exchanger, and the outlet pipe are connected in sequence, and the bypass valve is connected between the inlet pipe and the outlet pipe; the controller is used to execute the control method of the gas water heater described in the following embodiments.

[0047] Figure 1 is a schematic structural diagram of a gas water heater according to an embodiment of the present invention. As Figure 1 shown, the water inlet pipe, heat exchanger 1, water storage tank 2, and water outlet pipe of the gas water heater are connected in sequence. At the same time, a bypass pipe 3 is connected between the water inlet pipe and the water outlet pipe. A water flow sensor 4 and a water inlet temperature sensor 5 are provided on the water inlet pipe. Among them, the installation positions of the water flow sensor 4 and the water inlet temperature sensor 5 are located in the area between the water inlet and the connection point of the water inlet pipe and the bypass pipe 3. The water outlet pipe is connected to the bypass pipe 3 through a bypass valve 6, so as to adjust the cold water flow rate transported from the water inlet pipe to the water outlet pipe through the bypass valve 6. A first water outlet temperature sensor 7 and a second water outlet temperature sensor 8 are provided on the water outlet pipe. The first water outlet temperature sensor 7 is installed between the water storage tank 2 and the bypass valve 6 and is used to detect the water outlet temperature of the heat exchanger 1. The second water outlet temperature sensor 8 is installed between the bypass valve 6 and the water outlet and is used to detect the water outlet temperature of the gas water heater.

[0048] In one embodiment, the installation position of the bypass valve 6 can be adjusted according to design requirements, and it can be installed at any position that can achieve the adjustment of the ratio of cold water and hot water collected on the water outlet pipe, and no specific limitation is made here. For example, the bypass valve 6 can be installed on the bypass pipe 3, can be installed at the connection point of the water inlet pipe and the bypass pipe 3, can also be installed after the connection point of the water inlet pipe and the bypass pipe 3 on the water inlet pipe, or can be installed before the connection point of the water outlet pipe and the bypass pipe 3 on the water outlet pipe.

[0049] In one embodiment, the bypass valve 6 can adjust the water flow rates of both water mixing pipelines simultaneously, or can only adjust the water flow rate of one pipeline, which can be specifically adjusted according to the installation position of the bypass valve 6 and the water mixing requirements, and no specific limitation is made here. For example, when the bypass valve 6 is installed on the bypass pipe 3, the bypass valve 6 only adjusts the water flow rate on the bypass pipe 3; when the bypass valve is installed at the connection point of the bypass pipe 3 and the water outlet, the bypass valve 6 can adjust the water flow rates on both the bypass pipe 3 and the water outlet pipe simultaneously.

[0050] In one embodiment, the water storage tank 2 is only for illustration, and in actual design, any other form can be adopted to achieve the function of storing hot water. For example, extending the length of the water outlet pipe of the heat exchanger 1 can also achieve the function of storing hot water.

[0051] According to an embodiment of the present invention, on the other hand, a control method for a gas water heater is also provided, and this method can be applied to the above-mentioned gas water heater. Figure 2 is a schematic flow diagram of a control method for a gas water heater according to an embodiment of the present invention. As Figure 2 shown, this method includes:

[0052] Step 210: Obtain the target output heat and compare the target output heat with the minimum output heat of the gas water heater.

[0053] In an embodiment of the present invention, the target output heat is the heat required by the user for the current hot water demand. The minimum output heat of the gas water heater is the heat output when the gas water heater operates at the lowest output power, that is, the heat output when the heat exchanger of the gas water heater operates at the lowest heating power; the minimum output heat is the lower limit of the heat that the gas water heater can provide.

[0054] In one embodiment, the target output heat is also the heat required for the gas water heater to heat the cold water to the temperature required by the user. Therefore, the target output heat can be determined according to the target outlet temperature, the current inlet temperature, and the current water flow rate. Specifically, first, obtain the target outlet temperature, the current inlet temperature, and the current water flow rate; among them, the target outlet temperature is the temperature required by the user and can be determined according to the settings of the user for the gas water heater; the current inlet temperature is the temperature of the cold water entering the gas water heater through the inlet pipe and can be obtained through the inlet temperature sensor provided on the inlet pipe; the current water flow rate is the flow rate of the cold water entering the gas water heater through the inlet pipe and can be obtained through the water flow rate sensor provided on the inlet pipe. Then, based on the target outlet temperature, the current inlet temperature, and the current water flow rate, determine the target output heat; that is, multiply the difference between the target outlet temperature and the current inlet temperature by the current water flow rate to obtain the target output heat.

[0055] Step 220: If the target output heat is less than the minimum output heat, adjust the gas water heater to a preset working state.

[0056] In an embodiment of the present invention, if the target output heat is less than the minimum output heat, it indicates that even if the gas water heater operates at the lowest output power, its outlet temperature will be higher than the target outlet temperature and cannot meet the user's water use demand. Therefore, the gas water heater is adjusted to a preset working state and enters the adjustment mode, and the working state of the gas water heater is adjusted through the adjustment mode to meet the user's water use demand.

[0057] In one embodiment, the operating state of the gas water heater includes the bypass ratio of the bypass valve and the output power of the gas water heater. Correspondingly, the preset operating state includes the preset bypass ratio of the bypass valve and the preset output power of the gas water heater. Therefore, adjusting the gas water heater to the preset operating state specifically includes: adjusting the bypass ratio of the bypass valve to the first preset bypass ratio; adjusting the output power of the gas water heater to the preset output power. Usually, when the gas water heater is operating normally, the bypass valve is in the closed state and its bypass ratio is the first preset bypass ratio. Therefore, the bypass ratio of the bypass valve does not need to be adjusted during the adjustment mode of the gas water heater; the preset output power is greater than or equal to the minimum output power of the gas water heater, so as to ensure that the heat exchanger can operate normally during the combustion operation of the gas water heater.

[0058] In one embodiment, if the target output heat is greater than or equal to the minimum output heat, it indicates that the gas water heater is operating normally according to the requirement of the target output heat and can meet the user's water use demand. Therefore, the gas water heater is controlled to operate normally at this time. Specifically, if the target output heat is greater than or equal to the minimum output heat, the bypass ratio is adjusted to the first preset bypass ratio to close the bypass valve so that all the cold water entering the gas water heater passes through the heating of the heat exchanger; based on the target output heat, the output power of the gas water heater is adjusted so that the outlet water temperature of the gas water heater reaches the target outlet water temperature, thereby meeting the user's water use demand.

[0059] Step 230: Obtain the first outlet water temperature output by the gas water heater and the second outlet water temperature output by the heat exchanger.

[0060] In the embodiment of the present invention, the first outlet water temperature is the temperature of the hot water finally provided by the gas water heater to the user, that is, the actual outlet water temperature; the second outlet water temperature is the temperature of the hot water output after being heated by the heat exchanger; that is, the second outlet water temperature is the hot water temperature without converging the cold water transported by the bypass pipe.

[0061] Step 240: Adjust the operating state of the gas water heater based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature and the magnitude relationship between the second outlet water temperature and the target outlet water temperature.

[0062] In the embodiments of the present invention, as described above, the working state of the gas water heater includes the bypass ratio of the bypass valve and the output power of the gas water heater. According to the magnitude relationship between the first outlet water temperature and the target outlet water temperature, it can be determined whether the hot water temperature output by the current gas water heater can meet the user's demand for the outlet water temperature; according to the magnitude relationship between the second outlet water temperature and the target outlet water temperature, it can be determined whether the current output of the gas water heater can meet the user's demand for the outlet water temperature after being diluted and cooled by cold water. Based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature, and the magnitude relationship between the second outlet water temperature and the target outlet water temperature, the adjustment direction of the bypass ratio of the current bypass valve and the adjustment direction of the output power of the current gas water heater can be determined, and adjustments are made accordingly to meet the user's water use requirements; at the same time, when the difference between the target outlet water temperature and the second outlet water temperature is large, the ratio of cold and hot water can be adjusted by the bypass valve to reduce the gap between the target outlet water temperature and the outlet water temperature of the gas water heater. This can not only avoid frequent start and stop of the gas water heater, but also ensure that the change of the outlet water temperature of the gas water heater is relatively stable, without sudden increase or decrease, thereby improving the user's water use experience.

[0063] In one embodiment, the adjustment of the working state of the gas water heater includes the adjustment of the bypass ratio of the bypass valve and the adjustment of the output power of the gas water heater; specifically, Figure 3 is a schematic flow chart of adjusting the working state of the gas water heater in the control method of the gas water heater according to the embodiments of the present invention, as Figure 3 shown, the above step 240, based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature, and the magnitude relationship between the second outlet water temperature and the target outlet water temperature, adjusting the working state of the gas water heater may include the following steps:

[0064] Step 310: Adjust the bypass ratio of the bypass valve based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature.

[0065] In the embodiments of the present invention, based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature, it can be determined that diluting and cooling the hot water according to the current bypass ratio can meet the user's water use requirements. Specifically, if the first outlet water temperature is greater than the target outlet water temperature, it indicates that the outlet water temperature of the current gas water heater is too high, so the bypass ratio is increased to increase the cold water flow converging to the outlet pipe to lower the first outlet water temperature; if the first outlet water temperature is less than the target outlet water temperature, it indicates that the outlet water temperature of the current gas water heater is too low, so the bypass ratio is decreased to reduce the cold water flow converging to the outlet pipe to increase the first outlet water temperature.

[0066] Step 320: Adjust the output power of the gas water heater based on the magnitude relationship between the second outlet water temperature and the target outlet water temperature.

[0067] In the embodiment of the present invention, based on the magnitude relationship between the second outlet water temperature and the target outlet water temperature, it can be determined whether the first outlet water temperature can be adjusted to the target outlet water temperature by adjusting the bypass ratio of the bypass valve at the second outlet water temperature; if the first outlet water temperature cannot be adjusted to the target outlet water temperature, it indicates that the gas water heater cannot meet the user's demand for water temperature during the working state. Therefore, the output power of the gas water heater can be adjusted to zero to turn off the combustion of the gas water heater, thereby reducing the first outlet water temperature to the target outlet water temperature.

[0068] In one embodiment, a preset temperature difference can be used to measure whether the gas water heater can meet the user's demand for water temperature during the working state; the numerical value of the preset temperature difference is related to the capacity of the water storage tank. Generally speaking, the larger the capacity of the water storage tank, the smaller the preset temperature difference. Correspondingly, if the difference between the second outlet water temperature and the target outlet water temperature is greater than the preset temperature difference, it indicates that the gas water heater cannot meet the user's demand for water temperature during the working state. Therefore, the output power of the gas water heater is adjusted to zero to turn off the combustion of the gas water heater.

[0069] In one embodiment, the adjustments of the above steps 310 and 320 are independent of each other. After executing the above step 320, the bypass ratio of the bypass valve can still be adjusted based on step 310 to cool the hot water output from the water outlet pipe through natural cooling and cold water dilution cooling, thereby quickly reducing the first outlet water temperature to the target outlet water temperature.

[0070] In one embodiment, during the working process of the gas water heater, after adjusting the bypass ratio of the bypass valve, if the bypass ratio of the adjusted bypass valve reaches the second preset bypass ratio, the output power of the gas water heater is adjusted to zero to turn off the combustion of the gas water heater. Among them, the second preset bypass ratio is the bypass ratio when the bypass valve is fully opened; when the bypass ratio of the bypass valve reaches the second preset bypass ratio, it indicates that only relying on the bypass valve at this time cannot adjust the first outlet water temperature to the target outlet water temperature. Therefore, the output power of the gas water heater is adjusted to zero to turn off the combustion of the gas water heater.

[0071] In one embodiment, after adjusting the bypass ratio of the bypass valve after adjusting the output power of the gas water heater to zero to turn off the combustion of the gas water heater, if the bypass ratio of the bypass valve reaches the first preset bypass ratio, it indicates that the current second outlet water temperature is already close to the target outlet water temperature. Continuing to turn off the gas water heater at this time may cause the outlet water temperature to be lower than the target outlet water temperature. Therefore, the output power of the gas water heater is adjusted to the preset output power to turn on the combustion of the gas water heater and maintain the outlet water temperature of the gas water heater near the target outlet water temperature.

[0072] The control method of the gas water heater provided by the embodiment of the present invention obtains the target output heat and compares the target output heat with the minimum output heat of the gas water heater; if the target output heat is less than the minimum output heat, the gas water heater is adjusted to a preset working state; the first outlet water temperature output by the gas water heater and the second outlet water temperature output by the heat exchanger are obtained; based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature and the magnitude relationship between the second outlet water temperature and the target outlet water temperature, the working state of the gas water heater is adjusted; the working state includes the bypass ratio of the bypass valve and the output power of the gas water heater. Thus, when the target output heat of the gas water heater is less than the minimum output heat, the gas water heater is adjusted to the preset working state, and the working state of the gas water heater is adjusted by the magnitude relationship between the first outlet water temperature and the target outlet water temperature and the magnitude relationship between the second outlet water temperature and the target outlet water temperature. Therefore, when the target output heat required by the user is less than the minimum output heat that the gas water heater can provide, the output power of the gas water heater is maintained above the minimum output power, and at the same time, the outlet water temperature of the gas water heater is adjusted by adjusting the bypass ratio of the bypass valve, so that the outlet water temperature meets the user's water use requirements, and the gas water heater can be prevented from starting and stopping frequently, ensuring the stability of the outlet water temperature and improving the user's water use experience.

[0073] In the specific content of the above specific embodiment, each technical feature can be combined arbitrarily without contradiction. For the sake of concise description, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features does not exist in contradiction, it should be considered as the scope recorded in this specification.

[0074] The specific content of the above specific embodiment only expresses several embodiments of the present invention, and its description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A control method for a gas water heater, characterized in that, The gas water heater includes a water inlet pipe, a water outlet pipe, a heat exchanger, and a bypass valve. The water inlet pipe, the heat exchanger, and the water outlet pipe are connected in sequence, and the bypass valve is connected between the water inlet pipe and the water outlet pipe. The method includes: Obtain a target output heat quantity, and compare the target output heat quantity with the minimum output heat quantity of the gas water heater; If the target output heat quantity is less than the minimum output heat quantity, adjust the gas water heater to a preset working state; Obtain a first outlet water temperature output by the gas water heater and a second outlet water temperature output by the heat exchanger; Based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature, and the magnitude relationship between the second outlet water temperature and the target outlet water temperature, adjust the working state of the gas water heater; the working state includes the bypass ratio of the bypass valve and the output power of the gas water heater.

2. The method according to claim 1, wherein The adjusting the gas water heater to the preset working state includes: Adjust the bypass ratio of the bypass valve to a first preset bypass ratio; Adjust the output power of the gas water heater to a preset output power; the preset output power is greater than or equal to the minimum output power of the gas water heater.

3. The method according to claim 1, wherein The adjusting the working state of the gas water heater based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature, and the magnitude relationship between the second outlet water temperature and the target outlet water temperature includes: Adjust the bypass ratio of the bypass valve based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature; Adjust the output power of the gas water heater based on the magnitude relationship between the second outlet water temperature and the target outlet water temperature.

4. The method according to claim 3, characterized in that, The adjusting the bypass ratio of the bypass valve based on the magnitude relationship between the first outlet water temperature and the target outlet water temperature includes: If the first outlet water temperature is greater than the target outlet water temperature, increase the bypass ratio; If the first outlet water temperature is less than the target outlet water temperature, decrease the bypass ratio.

5. The method according to claim 3, characterized in that, The adjusting the output power of the gas water heater based on the magnitude relationship between the second outlet water temperature and the target outlet water temperature includes: If the difference between the second outlet water temperature and the target outlet water temperature is greater than a preset temperature difference, adjust the output power of the gas water heater to zero to turn off the combustion of the gas water heater.

6. The method according to claim 3, characterized in that, After adjusting the output power of the gas water heater to zero to turn off the combustion of the gas water heater, it further includes: If the bypass ratio of the bypass valve reaches the first preset bypass ratio, adjust the output power of the gas water heater to the preset output power to turn on the combustion of the gas water heater.

7. The method according to claim 1, characterized in that, The method further includes: If the bypass ratio of the bypass valve reaches a second preset bypass ratio after adjustment, adjust the output power of the gas water heater to zero to turn off the combustion of the gas water heater.

8. The method according to claim 1, characterized in that The obtaining the target output heat quantity includes: Obtain the target outlet water temperature, the current inlet water temperature, and the current water flow rate; Based on the target outlet water temperature, the current inlet water temperature, and the current water flow rate, determine the target output heat quantity.

9. The method according to claim 1, characterized in that, The method further includes: If the target output heat is greater than or equal to the minimum output heat, adjust the bypass ratio to a first preset bypass ratio; Based on the target output heat, adjust the output power of the gas water heater.

10. A gas water heater, characterized in that, It includes a water inlet pipe, a water outlet pipe, a heat exchanger, a bypass valve and a controller; The water inlet pipe, the heat exchanger and the water outlet pipe are connected in sequence, and the bypass valve is connected between the water inlet pipe and the water outlet pipe; the controller is used to execute the control method of the gas water heater according to any one of claims 1-9.

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