Auxiliary heating device, coil-free heat exchange device, gas water heater and control method

Abstract

The present invention provides an auxiliary heating device, a coil-free heat exchange device, a gas water heater and a control method, belonging to the field of kitchen utensils. The auxiliary heating device includes a heating body, a heating rod, a heating wire and a fixing ear. The heating body includes a hollow main body portion and a hollow heating rib provided on one side of the main body portion, and the main body portion and the heating rib communicate with each other. The heating rod is disposed within the heating rib. The heating wire is disposed within the main body portion, wherein the heating wire and the heating rod are used to heat the fluid flowing through the heating body. The fixing ear is fixedly connected to the heating rib and is used to fix the auxiliary heating device. This auxiliary heating device can be applied to a stainless steel coil-free heat exchange device to achieve the performance of auxiliary heating with low temperature rise and small flow rate.

Description

Technical Field

[0001] The present invention relates to the field of kitchen appliances, and particularly to an auxiliary heating device, a coil-free heat exchange device, a gas water heater, and an auxiliary heating control method for a gas water heater. Background Art

[0002] Affected by factors such as the demand for product quality improvement and cost pressure, the industry has gradually regarded the coil-free heat exchange main structure as an important research direction, which can effectively solve the problems of corrosion and water leakage and has a great cost advantage; however, its disadvantage is that it is difficult to install the electric anti-freeze heater, resulting in ineffective protection in extremely cold weather and prone to problems such as freezing and water leakage.

[0003] Due to the limitation of its minimum combustion load, the minimum temperature rise requirement of a gas water heater has always been a pain point for users. Often, users will complain that the water temperature is too high in summer and cannot meet the comfortable bathing needs; while electric auxiliary heating can achieve the output of low temperature rise requirements, and it is necessary to design how to combine an electric auxiliary heating device with a gas water heater to achieve the performance output of low temperature rise. Summary of the Invention

[0004] The purpose of the present invention is to provide an auxiliary heating device that can be applied to a stainless steel coil-free heat exchange device to achieve the performance of low temperature rise and small flow auxiliary heating.

[0005] The purpose of the present invention also lies in providing a coil-free auxiliary heating device.

[0006] The purpose of the present invention also lies in providing a gas water heater.

[0007] The purpose of the present invention also lies in providing an auxiliary heating control method for a gas water heater.

[0008] To achieve the purpose of the present invention, the present invention adopts the following technical solutions:

[0009] According to one aspect of the present invention, an auxiliary heating device is provided. The auxiliary heating device includes a heating body, a heating rod, a heating wire, and fixing ears. The heating body includes a hollow main body portion and a hollow heating rib provided on one side of the main body portion, and the main body portion and the heating rib communicate with each other. The heating rod is disposed in the heating rib. The heating wire is disposed in the main body portion, wherein the heating wire and the heating rod are used for heating the fluid flowing through the heating body. The fixing ears are fixedly connected to the heating rib for fixing the auxiliary heating device.

[0010] According to an embodiment of the present invention, the main body portion is a cuboid structure, and the heating ribs are multiple and symmetrically disposed on one side of the main body portion.

[0011] According to an embodiment of the present invention, the heating wire is arranged in a zigzag shape within the main body portion to increase the heat exchange area.

[0012] According to an embodiment of the present invention, the auxiliary heating device further includes a filling material, which is filled in the space between the heating wires for heat preservation.

[0013] According to another aspect of the present invention, a coil-less heat exchange device is provided. The coil-less heat exchange device includes a stainless-steel heat exchange main body and the aforementioned auxiliary heating device. Water box flow channel devices are arranged on both sides of the stainless-steel heat exchange main body, wherein the water box flow channel device includes a plurality of water box flow channel modules arranged in parallel. Among them, there are 2 auxiliary heating devices, and the 2 auxiliary heating devices are respectively installed on the water box flow channel module through fixing ears, so that each heating rib is inserted between two adjacent water box flow channel modules for heating the liquid flowing through the stainless-steel heat exchange main body.

[0014] According to yet another aspect of the present invention, a gas water heater is provided. The gas water heater includes a burner system, an exhaust system, a coil-less heat exchange device, an outlet water temperature sensor, an inlet water temperature sensor, a flow sensor, an operation panel, a temperature sensing probe, and a controller. The burner system is used for burning gas. The exhaust system is connected to the burner system. The coil-less heat exchange device is connected to the burner system and is used for heating the fluid flowing through it by the heat generated by the combustion of the burner system. The outlet water temperature sensor is used for detecting the temperature of the fluid flowing out of the gas water heater. The inlet water temperature sensor is used for detecting the temperature of the fluid flowing into the gas water heater. The flow sensor is used for detecting the flow rate of the fluid flowing into the gas water heater. The operation panel is provided with an auxiliary heating mode button for manually activating the auxiliary heating mode. The temperature sensing probe is used for sensing the temperature of the fluid inside the gas water heater. The controller is connected to the outlet water temperature sensor, the inlet water temperature sensor, and the flow sensor, and is used for selecting to turn on or off the auxiliary heating mode or the gas operation mode; the controller is connected to the temperature sensing probe and is used for turning on or off the anti-freezing heating mode; the controller is connected to and controls the burner system, the coil-less heat exchange device, and the operation panel.

[0015] According to yet another aspect of the present invention, an auxiliary heating control method for a gas water heater is provided. The method includes activating the auxiliary heating mode; measuring the inlet water temperature, the outlet water temperature, and the inlet water flow rate in real time and calculating the real-time required load Q according to the formula Q = CMΔt 实 ; if 0 < Q 实 <= Q 预设1 , then start one of the auxiliary heating devices; if Q 预设1 < Q实 <= Q 预设2 , then start two auxiliary heating devices simultaneously, where Q 预设2 > Q 预设1 ; if Q 实 > Q 预设2 , then exit the auxiliary heating mode and start the gas operation mode

[0016] According to an embodiment of the present invention, wherein the auxiliary heating control method further includes:

[0017] When the gas water heater is in the standby condition, the temperature sensing probe measures the fluid temperature t in the gas water heater in real time 1 ;

[0018] When t 1 < 5°C, start the anti-freezing heating mode, and heat the fluid in the gas water heater through one auxiliary heating device;

[0019] When t 1 >= 5°C and remains for more than 5 minutes, exit the anti-freezing heating mode.

[0020] According to an embodiment of the present invention, wherein the auxiliary heating mode is applied to an environment with small flow rate and low temperature rise, where the inlet water flow rate is greater than 2.5 L and less than 5 L, the temperature rise is less than 7°C, and the power of each auxiliary heating device is 600 w, Q 预设1 = 600 w ， Q 预设2 = 1200 w.

[0021] According to an embodiment of the present invention, wherein the activation of the auxiliary heating mode includes:

[0022] Turn on the auxiliary heating mode through the controller or manually operating the control panel;

[0023] After turning on the auxiliary heating mode, the gas water heater first enters the auxiliary heating mode to heat the internal fluid, but when the inlet water flow rate exceeds 5 L or the temperature rise is greater than 7°C, it directly enters the gas operation mode.

[0024] One embodiment of the present invention has the following advantages or beneficial effects:

[0025] The present invention provides an auxiliary heating device, including a coil-less heat exchange device of the auxiliary heating device, a gas water heater including the coil-less heat exchange device, and an auxiliary heating control method for the gas water heater.

[0026] The auxiliary heating device is installed on both sides of the coil-less heat exchange device, and the heating ribbed bars are cross-set with the water box flow channel module, solving the installation requirements of the heating module of the coil-less heat exchange device.

[0027] The auxiliary heating control method can effectively meet the user's demand for bathing water with a small amount of water and a low temperature rise.

[0028] The anti-freezing heating mode can ensure the water temperature in the gas water heater with no coil heat exchange device under cold conditions. Description of the Drawings

[0029] By describing its exemplary embodiments in detail with reference to the drawings, the above and other features and advantages of the present invention will become more apparent.

[0030] Figure 1 FIG. is a schematic diagram of an auxiliary heating device shown according to an exemplary embodiment.

[0031] Figure 2 FIG. is a cross-sectional schematic diagram of an auxiliary heating device shown according to an exemplary embodiment.

[0032] Figure 3 FIG. is a partially exploded schematic diagram of a coil-less heat exchange device shown according to an exemplary embodiment.

[0033] Figure 4 FIG. is a schematic diagram of a gas water heater shown according to an exemplary embodiment.

[0034] Figure 5 FIG. is a flowchart of an auxiliary heating control method shown according to an exemplary embodiment.

[0035] Among them, the description of the reference numerals is as follows:

[0036] 1. Heating body; 110. Main body part; 111. Heating rib; 2. Heating rod; 3. Heating wire; 4. Fixed ear; 5. Stainless steel heat exchange main body; 51. Water box flow channel device; 511. Water box flow channel module; 6. Burner system; 7. Exhaust system; 8. Outlet water temperature sensor; 9. Inlet water temperature sensor; 10. Flow sensor; 11. Operation panel; 12. Temperature sensing probe; 13. Controller; 14. Filling material. Detailed Embodiments

[0037] Now, the exemplary embodiments will be described more fully with reference to the drawings. However, the exemplary embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed descriptions will be omitted.

[0038] The terms "a", "an", "the", and "said" are used to indicate the presence of one or more elements / components / etc.; the terms "comprising" and "having" are used to mean an open inclusion and refer to the possibility of the existence of additional elements / components / etc. in addition to the listed elements / components / etc.

[0039] As Figures 1 to 4 shown, Figure 1 Fig. shows a schematic diagram of an auxiliary heating device provided by the present invention. Figure 2 Fig. shows a sectional schematic diagram of an auxiliary heating device provided by the present invention. Figure 3 Fig. shows a partially exploded schematic diagram of a coil-free heat exchange device provided by the present invention. Figure 4 Fig. shows a schematic diagram of a gas water heater provided by the present invention.

[0040] The auxiliary heating device according to an embodiment of the present invention includes a heating body 1, a heating rod 2, a heating wire 3, and a fixing ear 4. The heating body 1 includes a hollow main body portion 110 and a hollow heating rib 111 provided on one side of the main body portion 110, and the main body portion 110 and the heating rib 111 communicate with each other. The heating rod 2 is disposed within the heating rib 111. The heating wire 3 is disposed within the main body portion 110, wherein the heating wire 3 and the heating rod 2 are used to heat the fluid flowing through the heating body 1. The fixing ear 4 is fixedly connected to the heating rib 111 and is used to fix the auxiliary heating device. The main body portion 110 has a cuboid structure, and the heating ribs 111 are multiple and symmetrically disposed on one side of the main body portion 110.

[0041] Among them, the heating body 1 is a ceramic heater. The main body portion 110 has a plate-like structure in the shape of a cuboid, and the heating rib 111 also has a cuboid structure. The number of the heating ribs 111 can be one, two or more. However, the number thereof is less than that of the water box flow channel module 511. The main shape and size of the reinforcing rib 111 are determined by two adjacent water box flow channel modules 511, and the reinforcing rib 111 is embedded between the two water box flow channel modules 511 to achieve the function of enhancing heat conduction. Preferably, the number of the heating ribs 111 is 3. The fixing ear 4 can be disposed on one heating rib 111 or on all the heating ribs 111. When the number of the heating ribs 111 is 3, preferably the fixing ear 4 can be disposed on the middle heating rib 111. Through holes can be opened on the fixing ear 4 to be connected to the water box flow channel device 51 by bolts. The heating body 1, that is, the heating rib 111 and the main body portion 110, has a cavity.

[0042] In a preferred embodiment of the present invention, the heating wire 3 is arranged in a zigzag shape within the main body portion 110 to increase the heat exchange area. The filling material 14 is filled in the space between the heating wires 3 and is used for heat preservation.

[0043] As Figure 2As shown, the heating wire 3 is zigzag bent and arranged in the main body part 110, which can effectively increase the heat exchange area. The filling material 14 can not only play a heat preservation role but also support the heating wire 3.

[0044] The coil-less heat exchange device of the embodiment of the present invention includes a stainless steel heat exchange main body 5 and the auxiliary heating device as described above. Water box flow channel devices 51 are arranged on both sides of the stainless steel heat exchange main body 5. Among them, the water box flow channel device 51 includes a plurality of water box flow channel modules 511 arranged in parallel. There are 2 auxiliary heating devices, and the 2 auxiliary heating devices are respectively installed on the water box flow channel module 51 through fixing ears 4, so that each heating rib 111 is inserted between two adjacent water box flow channel modules 511 for heating the liquid flowing through the stainless steel heat exchange main body 5.

[0045] As Figure 3 shown, since the stainless steel heat exchange main body 5 is not easy to bend, the water box flow channel devices 4 are arranged on its left and right sides. At the same time, the auxiliary heating device is needed. One auxiliary heating device is fixed on the left and one on the right. At the same time, the heating rib 111 is inserted between two adjacent water box flow channel modules 511.

[0046] The gas water heater of the embodiment of the present invention includes a burner system 6, an exhaust system 7, the aforementioned coil-less heat exchange device, an outlet water temperature sensor 8, an inlet water temperature sensor 9, a flow sensor 10, an operation panel 11, a temperature sensing probe 12, and a controller 13. The burner system 6 is used for burning gas. The exhaust system 7 is communicated with the burner system 6. The coil-less heat exchange device is communicated with the burner system 6 and is used for heating the fluid flowing through it by the heat generated by the combustion of the burner system 6. The outlet water temperature sensor 8 is used for detecting the temperature of the fluid flowing out of the gas water heater. The inlet water temperature sensor 9 is used for detecting the temperature of the fluid flowing into the gas water heater. The flow sensor 10 is used for detecting the flow rate of the fluid flowing into the gas water heater. An auxiliary heating mode button is arranged on the operation panel 11 for manually activating the auxiliary heating mode. The temperature sensing probe 12 is used for sensing the temperature of the fluid in the gas water heater. The controller 13 is connected to the outlet water temperature sensor 8, the inlet water temperature sensor 9, and the flow sensor 10 and is used for selecting to turn on or off the auxiliary heating mode or the gas operation mode; the controller 13 is connected to the temperature sensing probe 12 and is used for turning on or off the anti-freezing heating mode; the controller 13 is connected to and controls the burner system 6, the coil-less heat exchange device, and the operation panel 11.

[0047] As Figure 4As shown, when the controller 13 determines that it is necessary to enter the gas operation mode, the burner system 6 is activated and air is provided to the burner system 6 from the exhaust system 7 at the same time so that the gas in the burner system 6 burns, and the generated heat is input into the coil-less heat exchange device to exchange heat with the fluid flowing through it. The outlet water temperature sensor 8 is installed at the outlet pipe of the gas water heater. The inlet water temperature sensor 9 is installed at the inlet pipe of the gas water heater. The flow sensor 10 is also installed at the inlet pipe of the gas water heater. The outlet water temperature sensor 8, the inlet water temperature sensor 9 and the flow sensor 10 can perform real-time detection and calculate the real-time temperature difference between the inlet and outlet water and the inlet water flow. The controller 13 can calculate the real-time demand load based on the data fed back. The temperature sensing probe 12 is used to detect the temperature of the fluid existing in the gas water heater in real time. The controller 13 determines whether to enter the anti-freezing heating mode based on the data fed back by the temperature sensing probe 12. The temperature sensing probe is a mechanical control switch and can be automatically disconnected or closed under the set temperature condition.

[0048] Figure 5 The flowchart of an auxiliary heating control method provided by the present invention is shown.

[0049] The auxiliary heating control method for the aforementioned gas water heater according to an embodiment of the present invention includes:

[0050] S1: Activate the auxiliary heating mode;

[0051] S2: Measure the inlet water temperature, the outlet water temperature, and the inlet water flow in real time and calculate the real-time demand load Q according to the formula Q = CMΔt 实 ;

[0052] S3: If 0 < Q 实 <= Q 预设1 , then start one of the auxiliary heating devices;

[0053] S4: If Q 预设1 < Q 实 <= Q 预设2 , then start two auxiliary heating devices simultaneously, where Q 预设2 > Q 预设1 ;

[0054] S5: If Q 实 > Q 预设2 , then exit the auxiliary heating mode and start the gas operation mode.

[0055] Such as Figure 5As shown, when the auxiliary heating mode is enabled, the system calculates the required load Q according to the formula: Q = CMΔt. As a further explanation of the above solution, Q represents the energy magnitude with the unit of joule (J). C represents the specific heat. M represents the mass of the fluid, and the calculation method is well-known and can be calculated through the flow rate of the fluid and the cross-sectional area of the pipeline, etc. ΔT represents the temperature rise of the fluid, and the calculation method is also well-known and can be calculated through the inlet water temperature sensor 9 and the outlet water temperature sensor 8. Q 预设1 and Q 预设2 The values of can be calculated. They are calculated according to the magnitude intervals of the inlet water flow rate and the temperature rise, and this value will ultimately also correspond to the power of the auxiliary heating device.

[0056] In a preferred embodiment of the present invention, when the gas water heater is in the standby condition, the temperature sensor 12 measures the temperature t of the fluid in the gas water heater in real time 1 ; when t 1 < 5°C, the anti-freezing heating mode is started, and a fluid in the gas water heater is heated by an auxiliary heating device; when t 1 ≥ 5°C and remains for more than 5 minutes, the anti-freezing heating mode is exited.

[0057] Among them, when the gas water heater is in the standby state, it is easy to burst due to the freezing of the water in the water pipe in an environment below zero. However, the gas water heater itself requires a reaction time, so the lower limit of the water temperature in the water pipe is set to 5°C. The temperature sensor 12 measures this temperature t 1 . The controller determines whether to enter the anti-freezing heating mode according to the relationship between t 1 and 5°C. According to the characteristics of the gas water heater and a large number of experiments, it is obtained that the anti-freezing heating mode can be exited when the temperature is higher than 5°C for 5 minutes continuously.

[0058] In a preferred embodiment of the present invention, the auxiliary heating mode is applied to an environment with a small flow rate and a low temperature rise. Among them, the inlet water flow rate is greater than 2.5 L and less than 5 L, the temperature rise is less than 7°C, and the power of each auxiliary heating device is 600 w, Q 预设1 = 600 w, Q 预设2 = 1200 w.

[0059] Among them, the auxiliary heating is generally applicable to the user's usage environment with small water flow and low temperature rise requirements. Preferably, the conditions for the need of auxiliary heating generally have an inlet water flow of less than 5L. Combining with the start-up flow rate of the water heater of 2.5L, so it should be a usage environment of 2.5 - 5L. The usage environment with the need of auxiliary heating has an inlet water temperature of 28 - 32 degrees in summer. Combining with the lowest set temperature of the water heater of 35 degrees, so the required temperature is 3 - 7°C. According to the formula: Q = CM△t, it is more appropriate that the power of the auxiliary heating device is approximately in the range of 600W - 1200W. Therefore, the power of a single auxiliary heating device is taken as 600W. Different powers can also be selected according to the situation.

[0060] In a preferred embodiment of the present invention, activating the auxiliary heating mode includes: turning on the auxiliary heating mode through the controller 13 or manually controlling the operation panel 11; after turning on the auxiliary heating mode, the gas water heater first enters the auxiliary heating mode to heat the internal fluid, but when the inlet water flow exceeds 5L or the temperature rise is greater than 7°C, it directly enters the gas operation mode.

[0061] Among them, in order to improve the user experience, the user can turn on the auxiliary heating mode through the manually controlled operation panel 11. At the same time, if the user forgets to turn it on, it can also be automatically turned on when the controller 13 detects suitable conditions. The gas water heater preferably first enters the auxiliary heating mode to heat the fluid with small flow and low temperature rise. When the inlet water flow exceeds 5L or the temperature rise exceeds 7°C, the auxiliary heating mode is skipped and the gas operation mode is entered.

[0062] The auxiliary heating control method of the present invention is applicable to the application environment with small flow and low temperature rise. The inlet water flow is generally between 2.5L and 5L, and the temperature rise is generally within 7°C. The water temperature in the gas water heater is detected in real time through the temperature sensor probe 12, so as to turn on the anti-freezing heating mode when the water temperature is lower than 5°C, ensuring that the water pipe of the gas water heater will not be frozen. The heating ribs 111 of the auxiliary heating device are arranged crosswise with the box flow channel module 511, and are also fixed to the water box flow channel device 51 through the fixing ears 4. Thus, an auxiliary heating device is added in the case of using the stainless steel heat exchange main body 5 without a coil heat exchange device. The auxiliary heating device is provided with a heating wire 3 and a heating rod 2. The heating wire 3 adopts a zigzag layout, increasing the heat exchange area. The filling material 14 between the heating wires 3 can play a good heat preservation effect and can also support the heating wire 3.

[0063] In the embodiments of the present invention, the term "plurality" refers to two or more, unless otherwise clearly defined. Terms such as "installation", "connection", "fixation" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0064] In the description of the embodiments of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the embodiments of the present invention.

[0065] In the description of this specification, the description of terms such as "one embodiment" and "one preferred embodiment" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0066] The above are only the preferred embodiments of the embodiments of the present invention, and are not used to limit the embodiments of the present invention. For those skilled in the art, the embodiments of the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present invention shall be included in the protection scope of the embodiments of the present invention.

Claims

1. A coil-less heat exchange device, characterized in that, it includes: a stainless steel heat exchange main body (5), with water box flow channel devices (51) arranged on both sides of the stainless steel heat exchange main body (5), wherein the water box flow channel devices (51) include a plurality of water box flow channel modules (511) arranged in parallel; an auxiliary heating device, the auxiliary heating device includes: a heating body (1), the heating body (1) includes a hollow main body part (110) and a hollow heating rib (111) arranged on one side of the main body part (110), the main body part (110) and the heating rib (111) communicate with each other; the main body part (110) is of a cuboid structure; a heating rod (2), the heating rod (2) is arranged in the heating rib (111); a heating wire (3), the heating wire (3) is arranged in the main body part (110), wherein the heating wire (3) and the heating rod (2) are used to heat the fluid flowing through the heating body (1); and a fixing ear (4), the fixing ear (4) is fixedly connected to the heating rib (111) for fixing the auxiliary heating device; there are a plurality of heating ribs (111) and they are symmetrically arranged on one side of the main body part (110); the heating wire (3) is arranged in a zigzag shape in the main body part (110) to increase the heat exchange area; the auxiliary heating device further includes a filling material (14), the filling material (14) is filled in the space between the heating wires (3) for heat preservation; wherein, there are 2 auxiliary heating devices, and the 2 auxiliary heating devices are respectively installed on the water box flow channel module (511) through the fixing ears (4) so that each heating rib (111) is inserted between two adjacent water box flow channel modules (511) for heating the liquid flowing through the stainless steel heat exchange main body (5).

2. A gas water heater, characterized in that, it includes: a burner system (6) for burning gas; an exhaust system (7) communicated with the burner system (6); the coil-less heat exchange device as described in claim 1, communicated with the burner system (6) for heating the fluid flowing through it by the heat generated by the combustion of the burner system (6); an outlet water temperature sensor (8) for detecting the temperature of the fluid flowing out of the gas water heater; an inlet water temperature sensor (9) for detecting the temperature of the fluid flowing into the gas water heater; a flow sensor (10) for detecting the flow rate of the fluid flowing into the gas water heater; an operation panel (11), with an auxiliary heating mode button arranged on the operation panel (11) for manually activating the auxiliary heating mode; a temperature sensing probe (12) for detecting the temperature of the fluid in the gas water heater; and A controller (13) is connected to the outlet water temperature sensor (8), the inlet water temperature sensor (9), and the flow sensor (10) and is configured to select to turn on or off the auxiliary heating mode or the gas operation mode; the controller (13) is connected to the temperature sensing probe (12) and is configured to turn on or off the anti-freezing heating mode; the controller (13) is connected to and controls the burner system (6), the coil-less heat exchange device, and the operation panel (11).

3. An auxiliary heating control method for a gas water heater as claimed in claim 2, characterized in that, it includes: Activating the auxiliary heating mode; Measure the inlet water temperature, outlet water temperature, and inlet water flow rate in real time and calculate the real-time demand load Q according to the formula Q = CMΔt 实 ; If 0 < Q 实 <= Q 预设1 , then start one of the auxiliary heating devices; If Q 预设1 < Q 实 <= Q 预设2 , then start two auxiliary heating devices simultaneously, where Q 预设2 > Q 预设1 ; If Q 实 > Q 预设2 , then exit the auxiliary heating mode and start the gas operation mode.

4. The auxiliary heating control method according to claim 3, characterized in that, it further includes: When the gas water heater is in the standby condition, the temperature sensing probe (12) measures the fluid temperature t inside the gas water heater in real time 1 ; When t 1 <When it is lower than 5°C, start the anti-freezing heating mode, and heat the fluid in the gas water heater through an auxiliary heating device; When t 1 >= 5°C and remains at this temperature for more than 5 minutes, the anti-freeze heating mode is exited.

5. The auxiliary heating control method according to claim 3, characterized in that, The auxiliary heating mode is applied to an environment with low flow rate and low temperature rise, where the inlet water flow rate is greater than 2.5 L and less than 5 L, the temperature rise is less than 7 °C, and the power of each auxiliary heating device is 600 w, Q 预设1 = 600 w, Q 预设2 = 1200 w.

6. The auxiliary heating control method according to claim 5, characterized in that, Activating the auxiliary heating mode includes: Turning on the auxiliary heating mode through the controller (13) or manually controlling the operation panel (11); After the auxiliary heating mode is turned on, the gas water heater first enters the auxiliary heating mode to heat the internal fluid, but when the inlet water flow rate exceeds 5 L or the temperature rise is greater than 7 °C, it directly enters the gas operation mode.

Images