Control method, controller, gas water heating device and heating system

Abstract

The present specification relates to the technical field of water heating, and specifically discloses a control method, a controller, a gas water heating device and a heating system. The method comprises: in the case of receiving a domestic water signal, controlling a flow adjusting device to adjust the flow of water flowing into a first pipeline to the inlet of a room heating device and the inlet of a first flow channel, so that part of the water flows to the inlet of the room heating device and the other part of the water flows to the inlet of the first flow channel; and according to a domestic water outlet temperature and a domestic water set temperature, controlling the flow adjusting device to adjust the ratio between the flow of water flowing into the first pipeline to the inlet of the room heating device and the flow of water flowing into the first flow channel. The domestic water outlet temperature is the temperature of water flowing out of the outlet of a second flow channel. The above scheme can effectively reduce the risk of domestic water outlet over-temperature and the volatility of domestic water outlet temperature, and improve the constant temperature experience of users.

Description

Technical Field

[0001] This specification relates to the field of water heating technology, and in particular to a control method, controller, gas-fired hot water device and heating system. Background Technology

[0002] Gas-fired wall-hung boilers provide both heating hot water and domestic hot water. During heating, the hot water from the boiler flows to the indoor heating systems. When hot water is needed, it flows to a heat exchanger where it exchanges heat with domestic hot water to produce domestic hot water.

[0003] However, when the wall-hung boiler is in heating mode, especially when using radiators, the temperature of the circulating water is relatively high (e.g., 80 degrees Celsius). When a domestic water demand signal is received during heating mode, the three-way valve is usually switched directly from the heating side to the domestic water side. Because all the high-temperature circulating water in the pipes enters the heat exchanger to exchange heat with the domestic water, the outlet temperature of the domestic water often exceeds the set temperature, resulting in a poor user experience.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This specification provides a control method, controller, gas-fired water heater, and heating system to solve the problem of excessive domestic water temperature after receiving a domestic water supply signal during heating in the prior art.

[0006] This specification provides a control method for a gas-fired water heater, comprising: a first heat exchanger; a burner for heating the first heat exchanger; a first pipeline and a second pipeline, the first pipeline for directing at least a portion of the water flowing from the outlet of the first heat exchanger to an indoor heating system, and the second pipeline for returning water flowing through the indoor heating system to the inlet of the first heat exchanger; and a second heat exchanger having a first flow channel and a second flow channel isolated from each other, the inlet of the first flow channel being connected to the first pipeline to allow at least a portion of the water in the first pipeline to flow into the inlet of the first flow channel, and the outlet of the first flow channel being connected to the second pipeline to allow water flowing out of the outlet of the first flow channel to flow into the second flow channel. The system includes: a second pipe for domestic water flow, where water flowing through the first pipe and water flowing through the second pipe can exchange heat; a flow regulating device for regulating the flow rate of water flowing into the first pipe to the inlet of the indoor heating equipment and the inlet of the first pipe; and a circulation pump installed on either the first or second pipe, which drives water flowing from the outlet of the indoor heating equipment into the second pipe to flow through the first heat exchanger and then from the first pipe to the inlet of the indoor heating equipment. The circulation pump also drives water flowing from the outlet of the first pipe into the second pipe to flow through the first heat exchanger and then from the first pipe to the inlet of the first pipe.

[0007] The control method includes:

[0008] Step S10: When a domestic water signal is received during heating, the flow regulating device is controlled to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that a portion of the water flows to the inlet of the indoor heating equipment and the other portion flows to the inlet of the first flow channel.

[0009] Step S20: Based on the domestic water outlet temperature and the domestic water set temperature, control the flow regulating device to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel; the domestic water outlet temperature is the temperature of the water flowing out of the outlet of the second flow channel.

[0010] In one embodiment, in step S10, the flow rate of the portion of water flowing to the inlet of the indoor heating equipment is greater than the flow rate of the other portion of water flowing to the inlet of the first flow channel, where the flow rate of the other portion of water is a preset flow rate; or,

[0011] Step S10 specifically includes:

[0012] Based on the temperature difference between the heating outlet water temperature and the set domestic water temperature and / or the domestic water flow rate at the inlet of the second flow channel, the flow regulating device controls the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that a portion of the water flows to the inlet of the indoor heating equipment and another portion flows to the inlet of the first flow channel; the flow rate of the other portion of water flowing to the inlet of the first flow channel is negatively correlated with the temperature difference, and / or, the flow rate of the other portion of water flowing to the inlet of the first flow channel is positively correlated with the domestic water flow rate; the heating outlet water temperature is the temperature of the water flowing out of the outlet of the first heat exchanger.

[0013] In one embodiment, step S10 specifically includes:

[0014] When a domestic water signal is received during heating mode, it is determined whether the temperature difference between the heating outlet water temperature and the set domestic water temperature is greater than a first preset temperature difference; the heating outlet water temperature is the temperature of the water flowing out of the outlet of the first heat exchanger; the first preset temperature difference is greater than zero.

[0015] If the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than the first preset temperature difference, the flow regulating device is controlled to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that a part of the water flows to the inlet of the indoor heating equipment and the other part flows to the inlet of the first flow channel.

[0016] In one embodiment, step S10 specifically includes:

[0017] When a domestic water signal is received during heating mode, it is determined whether the temperature difference between the heating outlet water temperature and the set domestic water temperature is greater than a first preset temperature difference; the heating outlet water temperature is the temperature of the water flowing out of the outlet of the first heat exchanger; the first preset temperature difference is greater than zero.

[0018] If the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than the first preset temperature difference, the burner is controlled to stop burning or maintain the stopped burning state; the flow regulating device is controlled to regulate the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that a part of the water flows to the inlet of the indoor heating equipment and the other part of the water flows to the inlet of the first flow channel.

[0019] In one embodiment, after determining whether the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than a first preset temperature difference, the method further includes:

[0020] Step S30: If the temperature difference between the heating outlet water temperature and the domestic water set temperature is not greater than the first preset temperature difference, control the burner to start combustion or maintain combustion state, and control the flow regulating device to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that all the water flowing into the first pipeline flows to the inlet of the first flow channel.

[0021] In one embodiment, after step S30, the method further includes:

[0022] The target power of the gas-fired water heater is determined based on the current required load, and the burner is controlled to ignite and heat the first heat exchanger based on the target power.

[0023] In one embodiment, after step S20, the method further includes:

[0024] Determine whether the domestic water usage time has reached the preset time;

[0025] If it is determined that the domestic water usage time has not reached the preset time, it is determined whether the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than a second preset temperature difference; the second preset temperature difference is greater than zero.

[0026] If it is determined that the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than the second preset temperature difference, return to step S20.

[0027] In one embodiment, the method further includes:

[0028] Step S40: If it is determined that the domestic water usage time has reached the preset time or if it is determined that the temperature difference between the heating outlet water temperature and the domestic water set temperature is not greater than the second preset temperature difference, the flow regulating device is controlled to adjust the flow rate of the water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that all the water flowing into the first pipeline flows to the inlet of the first flow channel.

[0029] In one embodiment, after step S40, the method further includes:

[0030] Step S50: Control the circulation pump to start or stop according to the domestic water outlet temperature and the domestic water set temperature, so that the domestic water outlet temperature is close to the domestic water set temperature.

[0031] In one embodiment, step S50 specifically includes:

[0032] If the temperature of the domestic water outlet is higher than the set temperature of the domestic water, the circulation pump shall be stopped.

[0033] When the temperature of the domestic water outlet is not higher than the set temperature of the domestic water, the circulation pump is controlled to start working.

[0034] In one embodiment, step S50 specifically includes:

[0035] If the temperature of the domestic water outlet is higher than the set temperature of the domestic water and the temperature difference between the two is greater than a first difference value, the circulation pump is controlled to stop working for a first preset time.

[0036] When the set temperature of the domestic water is higher than the outlet temperature of the domestic water and the temperature difference between the two is greater than a second difference value, the circulation pump is controlled to start working for a second preset time.

[0037] In one embodiment, after step S40 or step S50, the method further includes:

[0038] Based on the heating water outlet temperature, the domestic water set temperature, and the domestic water flow rate at the inlet of the second flow channel, determine whether the ignition conditions are met.

[0039] If the ignition conditions are met, the burner is controlled to start combustion;

[0040] The target power of the gas-fired water heater is determined based on the current required load, and the burner is controlled to ignite and heat the first heat exchanger based on the target power.

[0041] In one embodiment, step S10 specifically includes:

[0042] When a domestic water signal is received during heating mode, it is determined whether the temperature difference between the heating outlet water temperature and the set domestic water temperature is greater than a first preset temperature difference; the heating outlet water temperature is the temperature of the water flowing out of the outlet of the first heat exchanger; the first preset temperature difference is greater than zero.

[0043] If the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than the first preset temperature difference, the burner is controlled to burn according to the minimum power; the flow regulating device is controlled to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that a part of the water flows to the inlet of the indoor heating equipment and the other part flows to the inlet of the first flow channel.

[0044] In one embodiment, step S20 specifically includes:

[0045] The burner is controlled to burn according to the temperature difference between the heating water outlet temperature and the domestic water set temperature, so that the temperature difference between the heating water outlet temperature and the domestic water set temperature is close to the second preset temperature difference; according to the domestic water outlet temperature and the domestic water set temperature, the flow regulating device is controlled to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, until all the water flowing into the first pipeline flows to the inlet of the first flow channel.

[0046] In one embodiment, after step S20, the method further includes:

[0047] The target power of the gas-fired water heater is determined based on the current required load, and the burner is controlled to ignite and heat the first heat exchanger based on the target power.

[0048] In one embodiment, step S20 specifically includes:

[0049] When the domestic water outlet temperature is higher than the domestic water set temperature, the flow regulating device is controlled to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, so that the flow rate diverted to the inlet of the first flow channel is reduced.

[0050] When the domestic water outlet temperature is lower than the domestic water set temperature, the flow regulating device adjusts the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, thereby increasing the flow rate diverted to the inlet of the first flow channel.

[0051] In one embodiment, step S20 specifically includes:

[0052] Determine whether the outlet temperature of the domestic water is greater than the sum of the set domestic water temperature and the third preset temperature difference; the third preset temperature difference is greater than zero;

[0053] If it is determined that the temperature of the domestic water outlet is greater than the sum of the domestic water set temperature and the third preset temperature difference, the flow regulating device is controlled to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first channel, so that the flow rate to the inlet of the first channel is reduced.

[0054] In one embodiment, after determining whether the outlet temperature of the domestic water is greater than the sum of the set domestic water temperature and the third preset temperature difference, the method further includes:

[0055] If it is determined that the outlet temperature of the domestic water is not greater than the sum of the set domestic water temperature and the third preset temperature difference, then it is determined whether the outlet temperature of the domestic water is greater than the sum of the set domestic water temperature and the fourth preset temperature difference; the fourth preset temperature difference is greater than zero and less than the third preset temperature difference.

[0056] If it is determined that the temperature of the domestic water outlet is greater than the sum of the domestic water set temperature and the fourth preset temperature difference, the flow regulating device is controlled to keep the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first channel constant, so that the flow rate to the inlet of the first channel remains constant.

[0057] In one embodiment, step S20 specifically includes:

[0058] Determine whether the outlet temperature of the domestic water is less than the difference between the set domestic water temperature and the fifth preset temperature difference; the fifth preset temperature difference is greater than zero.

[0059] If it is determined that the temperature of the domestic water outlet is less than the difference between the domestic water set temperature and the fifth preset temperature difference, the flow regulating device is controlled to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first channel, so that the flow rate to the inlet of the first channel increases by a first magnitude.

[0060] In one embodiment, after determining whether the domestic water outlet temperature is less than the difference between the domestic water set temperature and the fifth preset temperature difference, the method further includes:

[0061] If it is determined that the domestic water outlet temperature is not less than the difference between the domestic water set temperature and the fifth preset temperature difference, then it is determined whether the domestic water outlet temperature is less than the domestic water set temperature.

[0062] If the temperature of the domestic water outlet is determined to be lower than the set temperature of the domestic water, the flow regulating device is controlled to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first channel, so that the flow rate to the inlet of the first channel increases by a second magnitude, the second magnitude being smaller than the first magnitude.

[0063] In one embodiment, after determining whether the domestic water outlet temperature is lower than the domestic water set temperature, the method further includes:

[0064] If it is determined that the domestic water outlet temperature is not less than the domestic water set temperature, it is determined whether the domestic water outlet temperature is less than the sum of the domestic water set temperature and the sixth preset temperature difference; the sixth preset temperature difference is greater than zero.

[0065] If it is determined that the temperature of the domestic water outlet is less than the sum of the domestic water set temperature and the sixth preset temperature difference, the flow regulating device is controlled to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, so that the flow rate to the inlet of the first flow channel increases by a third magnitude, the third magnitude being less than the second magnitude.

[0066] In one embodiment, after controlling the burner to burn according to the target power to heat the first heat exchanger, the method further includes:

[0067] When the heating outlet water temperature is greater than the sum of the domestic water set temperature and the first preset temperature difference, the burner is controlled to stop burning.

[0068] This specification also provides a controller, including a processor and a memory for storing processor-executable instructions, wherein the processor executes the instructions to implement the steps of the gas water heater control method described in any of the above embodiments.

[0069] This specification also provides a gas-fired water heating device, which includes:

[0070] The controller described in the above embodiments;

[0071] First heat exchanger;

[0072] A burner for heating the first heat exchanger;

[0073] A first pipeline and a second pipeline, wherein the first pipeline is used to direct at least a portion of the water flowing out of the outlet of the first heat exchanger to the indoor heating equipment, and the second pipeline is used to return the water flowing through the indoor heating equipment to the inlet of the first heat exchanger.

[0074] The second heat exchanger has a first flow channel and a second flow channel that are isolated from each other. The inlet of the first flow channel can be connected to the first pipeline so that at least part of the water in the first pipeline can flow into the inlet of the first flow channel. The outlet of the first flow channel can be connected to the second pipeline so that the water flowing out of the outlet of the first flow channel can flow into the second pipeline. The second flow channel is used for circulating domestic water. The water flowing through the first flow channel and the water flowing through the second flow channel can exchange heat.

[0075] A flow regulating device is used to regulate the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel;

[0076] A circulation pump is installed on the first pipeline or the second pipeline. The circulation pump can be used to drive water flowing from the outlet of the indoor heating equipment into the second pipeline to flow through the first heat exchanger and then from the first pipeline to the inlet of the indoor heating equipment. The circulation pump is also used to drive water flowing from the outlet of the first channel into the second pipeline to flow through the first heat exchanger and then from the first pipeline to the inlet of the first channel.

[0077] In one embodiment, the flow regulating device includes a three-way valve;

[0078] The first port of the three-way valve is connected to the first pipeline, the second port of the three-way valve is connected to the inlet of the first flow channel, and the third port of the three-way valve is connected to the inlet of the indoor heating equipment.

[0079] or,

[0080] The first port of the three-way valve is connected to the second pipeline, the second port of the three-way valve is connected to the outlet of the first flow channel, and the third port of the three-way valve is connected to the outlet of the indoor heating equipment.

[0081] In one embodiment, the gas-fired water heater further includes: a first connecting pipe for connecting the inlet of the first pipe and the inlet of the first flow channel; and a second connecting pipe for connecting the outlet of the second pipe and the first flow channel.

[0082] The flow regulating device includes:

[0083] A first valve is installed on the first connecting pipe or the second connecting pipe to regulate the flow rate of water flowing into or out of the first flow channel.

[0084] The second valve is disposed on the first pipe between the first connecting portion between the first pipe and the first connecting pipe and the inlet of the indoor heating equipment, to regulate the water flow rate into the indoor heating equipment; or, the second valve is disposed on the second pipe between the second connecting portion between the second pipe and the second connecting pipe and the outlet of the indoor heating equipment, to regulate the water flow rate out of the indoor heating equipment.

[0085] In one embodiment, the gas-fired water heater further includes:

[0086] The first temperature sensor is used to detect the heating water outlet temperature, which is the water temperature flowing out of the outlet of the first heat exchanger.

[0087] The second temperature sensor is used to detect the temperature of the domestic water outlet, which is the water temperature flowing out of the outlet of the second flow channel of the second heat exchanger.

[0088] This specification also provides a heating system in its embodiments, including:

[0089] The gas-fired water heating device described in any of the above embodiments;

[0090] An indoor heating device, wherein the inlet of the indoor heating device is connected to the outlet of the first heat exchanger via a first pipe, and the outlet of the indoor heating device is connected to the inlet of the first heat exchanger via a second pipe.

[0091] The technical solution in this specification has the following significant advantages:

[0092] The gas-fired water heater control method described in this specification allows the gas-fired water heater to operate in two states: heating and domestic hot water. In heating mode, water from the outlet of the first heat exchanger (heated by the burner) flows into the first pipe, and all the water flowing into the first pipe flows into the indoor heating equipment for heating. In domestic hot water mode, water from the outlet of the first heat exchanger (heated by the burner) flows into the first pipe, and at least a portion of the water flowing into the first channel of the second heat exchanger flows into the second channel to exchange heat with the domestic water in the second channel, thus providing domestic hot water. In heating mode, if a user water usage signal is received, the flow regulating device is controlled to adjust the flow rate of water flowing into the first pipe to the inlet of the indoor heating equipment and the inlet of the first channel, so that a portion of the water flows to the inlet of the indoor heating equipment and the other portion flows to the inlet of the first channel. Compared to existing technologies where, upon receiving a domestic water signal during heating, the flow regulating device directs the water flowing into the first pipe from the inlet of the indoor heating equipment to the inlet of the first channel, this embodiment controls the flow regulating device to divert water flowing into the first pipe to both the inlet of the indoor heating equipment and the inlet of the first channel. This results in a portion of the water flowing into the indoor heating equipment and the other portion flowing to the inlet of the first channel, thus reducing the flow rate of hot water into the inlet of the first channel. This reduces the heat exchange between the hot water in the first channel and the domestic water in the second channel, lowering the temperature of the domestic water exiting the second channel. This prevents the domestic water from overheating, reducing the risk of scalding and improving the user experience. Furthermore, after controlling a portion of the water flowing into the first pipe to flow to the inlet of the indoor heating equipment and the other portion to flow to the inlet of the first channel, the flow regulating device can adjust the ratio between the flow rate of water flowing into the first pipe to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first channel, based on the domestic water outlet temperature and the set domestic water temperature. That is, the flow regulating device is then used to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first channel, based on the temperature difference between the domestic water outlet temperature and the domestic water set temperature, so that the temperature of the domestic water flowing out of the second channel is close to the domestic water set temperature.By employing the above method, when a domestic water supply signal is received during heating mode, the heating water circuit (including the water flowing to the inlet of the indoor heating equipment) is not immediately shut off. Instead, a preliminary diversion is performed. By controlling the flow regulation device, the high-temperature water flowing out of the first heat exchanger simultaneously flows to the indoor heating equipment and the first flow channel of the second heat exchanger. This preliminary diversion reduces the amount of water entering the first flow channel of the second heat exchanger, thereby reducing heat input at the source. This ensures that only a portion of the water flows into the first flow channel of the second heat exchanger to exchange heat with the domestic water flowing into the second flow channel, preventing a sudden spike in the temperature of the domestic water exiting the second flow channel of the second heat exchanger and avoiding severe overheating. Moreover, during the preliminary diversion, the heating water circuit is not completely shut off; high-temperature water still flows through the indoor heating equipment, preventing a sudden drop in indoor temperature and minimizing the impact on heating comfort. Subsequently, dynamic proportional adjustment is performed. Based on the domestic water outlet temperature and the set domestic water temperature, the flow rate regulation device fine-tunes the ratio of water flow to the inlet of the indoor heating equipment and the inlet of the first flow channel. By adjusting this ratio, the amount of hot water entering the first flow channel of the second heat exchanger is controlled, thereby precisely controlling the heat exchange of the second heat exchanger and ultimately stabilizing the domestic water outlet temperature near the set domestic water temperature. This reduces fluctuations in the domestic water outlet temperature, improves the user's constant temperature experience, ensures user water safety, and reduces the impact of domestic water use on indoor heating comfort, thus balancing the stability and comfort of the heating system.

[0093] Specific embodiments of the invention are disclosed in detail below with reference to the description and accompanying drawings, indicating how the principles of the invention can be employed. It should be understood that the embodiments of the invention are not therefore limited in scope. Features described and / or shown for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0094] It should be emphasized that the term "comprising / including" as used herein refers to the presence of a feature, part, step, or component, but does not exclude the presence or addition of one or more other features, parts, steps, or components. Attached Figure Description

[0095] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances. In the drawings:

[0096] Figure 1A schematic diagram of the structure of a gas-fired water heater according to one embodiment of this specification is shown;

[0097] Figure 2 A schematic diagram of the structure of a gas-fired water heater according to one embodiment of this specification is shown;

[0098] Figure 3 A schematic diagram of the structure of a gas-fired water heater according to one embodiment of this specification is shown;

[0099] Figure 4 A flowchart of a control method for a gas-fired hot water device according to one embodiment of this specification is shown;

[0100] Figure 5 A flowchart of a control method for a gas-fired hot water device according to one embodiment of this specification is shown;

[0101] Figure 6 A flowchart of a control method for a gas-fired hot water device according to one embodiment of this specification is shown;

[0102] Figure 7 A flowchart of a control method for a gas-fired hot water device according to one embodiment of this specification is shown.

[0103] The reference numerals in the above figures are as follows:

[0104] 10. Gas-fired hot water unit; 101. First heat exchanger; 102. Burner; 103. First pipeline; 104. Second pipeline; 105. Second heat exchanger; 106. Flow regulating device; 107. Circulating pump; 108. First temperature sensor; 109. Second temperature sensor; 151. First flow channel; 152. Second flow channel; 153. First connecting pipeline; 154. Second connecting pipeline; 161. First three-way valve; 162. Second three-way valve; 163. First valve; 164. Second valve;

[0105] 20. Indoor heating equipment; 30. Domestic water supply system. Detailed Implementation

[0106] The principles and spirit of this specification will now be described with reference to several exemplary embodiments. It should be understood that these embodiments are given merely to enable those skilled in the art to better understand and implement this specification, and are not intended to limit the scope of this specification in any way. Rather, these embodiments are provided to make this disclosure more thorough and complete, and to fully convey the scope of this disclosure to those skilled in the art.

[0107] Those skilled in the art will recognize that the embodiments described in this specification can be implemented as a system, apparatus, method, or computer program product. Therefore, the disclosure of this specification can be specifically implemented in the following forms: entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software.

[0108] The details of the present invention can be more clearly understood by referring to the accompanying drawings and the description of specific embodiments. However, the specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on the invention, all of which should be considered within the scope of the invention. It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there may be an intervening element. The terms "mounted," "connected," and "connected" should be interpreted broadly, for example, they can refer to mechanical or electrical connections, or internal communication between two elements, and can be direct or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0109] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this specification belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this specification. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0110] This specification provides a method for controlling a gas-fired hot water device. Figures 1 to 3 A schematic diagram of a gas-fired water heater according to one embodiment of this specification is shown. Figures 1 to 3 As shown, the gas-fired hot water device 10 includes: a first heat exchanger 101, a burner 102, a first pipeline 103 and a second pipeline 104, a second heat exchanger 105, a flow regulating device 106 and a circulating pump 107.

[0111] The burner 102 is used for gas combustion. In one embodiment, the burner 102 and the first heat exchanger 101 can be arranged opposite each other and the burner 102 can supply heat energy to the first heat exchanger 101. The burner 102 can be in a combustion state and an off state; in the combustion state, it is used to heat the first heat exchanger 101. The first heat exchanger 101 heats the water flowing through it under the heat energy supplied by the burner 102, thereby obtaining hot water that meets the demand.

[0112] The first pipe 103 and the second pipe 104 are internal pipes of the gas-fired water heater 10. The first pipe 103 is used to allow at least a portion of the water flowing out of the outlet of the first heat exchanger 101 to flow to the indoor heating equipment 20. At least a portion of the water flowing out of the outlet of the first heat exchanger 101 is transported to the indoor heating equipment 20 via the first pipe 103 and the indoor piping. The second pipe 104 is used to return the water flowing through the indoor heating equipment 20 to the inlet of the first heat exchanger 101. The water flowing through the indoor heating equipment 20 returns to the inlet of the first heat exchanger 101 via the indoor piping and the second pipe 104. At least a portion of the water flowing out of the outlet of the first heat exchanger 101 flows into the indoor heating equipment 20 via the first pipe 103 and the indoor piping, and then flows back to the first heat exchanger 101 via the indoor piping and the second pipe 104 to meet the user's indoor heating needs.

[0113] The second heat exchanger 105 has a first flow channel 151 and a second flow channel 152 that are isolated from each other. The inlet of the first flow channel 151 can be connected to the first pipe 103 so that at least a portion of the water in the first pipe 103 can flow into the inlet of the first flow channel 151. The outlet of the first flow channel 151 can be connected to the second pipe 104 so that water flowing out of the outlet of the first flow channel 151 can flow into the second pipe 104. The second flow channel 152 can be connected to the domestic water supply device 30 for circulating domestic water. The water flowing through the first flow channel 151 and the water flowing through the second flow channel 152 can exchange heat. By providing the second heat exchanger 105, the gas-fired water heater 10 can heat domestic water to meet the user's hot water needs.

[0114] The flow regulating device 106 is used to direct the water flowing into the first pipe 103 to the inlet of the indoor heating equipment 20 and / or the inlet of the first flow channel 151. The flow regulating device 106 can regulate the flow rate of the water flowing into the first pipe 103 to the indoor heating equipment 20 and to the first flow channel 151, and this regulation can include gradually increasing or decreasing it.

[0115] A circulation pump 107 can be installed on either the first pipe 103 or the second pipe 104. The circulation pump 107 can be used to drive water flowing from the outlet of the indoor heating equipment 20 into the second pipe 104, through the first heat exchanger 101, and then from the first pipe 103 to the inlet of the indoor heating equipment 20. The circulation pump 107 can also be used to drive water flowing from the outlet of the first flow channel 151 into the second pipe 104, through the first heat exchanger 101, and then from the first pipe 103 to the inlet of the first flow channel 151. For example, as shown... Figures 1 to 3 As shown, the circulating pump 107 can be installed on the second pipeline 104.

[0116] like Figure 1 and Figure 2 As shown, in some embodiments of this specification, the flow regulating device 106 may include a three-way valve.

[0117] like Figure 1 As shown, in some embodiments of this specification, the first port of the first three-way valve 161 is connected to the first pipeline 103, the second port of the first three-way valve 161 is connected to the inlet of the first flow channel 151, and the third port of the first three-way valve 161 is connected to the inlet of the indoor heating equipment 20.

[0118] like Figure 2 As shown, in some embodiments of this specification, the first port of the second three-way valve 162 is connected to the second pipeline 104, the second port of the second three-way valve 162 is connected to the outlet of the first flow channel 151, and the third port of the second three-way valve 162 is connected to the outlet of the indoor heating equipment 20.

[0119] like Figures 1 to 3 As shown in some embodiments of this specification, the gas-fired water heater 10 may further include: a first connecting pipe 153 and a second connecting pipe 154. The first connecting pipe 153 is used to connect the inlet of the first pipe 103 and the first flow channel 151. The second connecting pipe 154 is used to connect the outlet of the second pipe 104 and the first flow channel 151.

[0120] like Figure 3 As shown, in some embodiments of this specification, the flow regulating device 106 may include a first valve 163 and a second valve 164. The first valve 163 may be disposed on the first connecting pipe 153 or the second connecting pipe 154 to regulate the water flow rate flowing into or out of the first flow channel 151. This regulation may include gradually increasing or decreasing the flow rate. In one embodiment, the first valve 163 may be a solenoid valve. By adjusting the first valve 163, the water flow rate from the first pipe 103 to the first flow channel 151 can be regulated.

[0121] In one embodiment, a second valve 164 is disposed on the first pipe 103 between the first connecting portion between the first pipe 103 and the first connecting pipe 153 and the inlet of the indoor heating device 20, to regulate the water flow rate into the indoor heating device 20. In another embodiment, a second valve 164 is disposed on the second pipe 104 between the second connecting portion between the second pipe 104 and the second connecting pipe 154 and the outlet of the indoor heating device 20, to regulate the water flow rate out of the indoor heating device 20. This regulation may include gradually increasing or decreasing the flow rate. By adjusting the second valve 164, the water flow rate from the first pipe 103 to the indoor heating device 20 can be regulated.

[0122] like Figure 3 As shown, the first valve 163 can be installed on the first connecting pipe 153, and the second valve 164 can be installed on the first pipe 103 between the first connecting part and the inlet of the indoor heating equipment 20. In one embodiment, the second valve 164 can be a solenoid valve.

[0123] In some embodiments of this specification, the gas-fired water heater 10 further includes a first temperature sensor 108 and a second temperature sensor 109. The first temperature sensor 108 is used to detect the heating outlet water temperature, which is the water temperature flowing out of the outlet of the first heat exchanger 101. The second temperature sensor 109 is used to detect the domestic water outlet water temperature, which is the water temperature flowing out of the outlet of the second flow channel 152 of the second heat exchanger 105.

[0124] Figure 4 A flowchart of a gas-fired water heater control method according to one embodiment of this specification is shown. While this specification provides method operation steps or apparatus structures as illustrated in the following embodiments or figures, more or fewer operation steps or module units may be included in the method or apparatus based on conventional or non-inventive effort. In steps or structures where there is no logically necessary causal relationship, the execution order of these steps or the module structure of the apparatus is not limited to the execution order or module structure described in the embodiments and figures of this specification. When the method or module structure is applied in actual devices or end products, it can be executed sequentially or in parallel (e.g., in a parallel processor or multi-threaded processing environment, or even a distributed processing environment) according to the method or module structure shown in the embodiments or figures.

[0125] Specifically, such as Figure 4 As shown, the control method for a gas-fired hot water device provided in one embodiment of this specification may include the following steps.

[0126] Step S10: When a domestic water signal is received during heating, the flow regulating device is controlled to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that a portion of the water flows to the inlet of the indoor heating equipment and the other portion flows to the inlet of the first flow channel.

[0127] The control method described in this specification can be applied to the gas-fired water heater described above. The operating states of the gas-fired water heater can include heating state and domestic hot water state. In heating state, water flowing from the outlet of the first heat exchanger heated by the burner flows into the first pipe, and all the water flowing into the first pipe flows into the indoor heating equipment for heating. In domestic hot water state, water flowing from the outlet of the first heat exchanger heated by the burner flows into the first pipe, and at least a portion of the water flowing into the first channel of the second heat exchanger flows into the second channel to exchange heat with the domestic water in the second channel to provide domestic hot water. In heating state, if a user water usage signal is received, the flow regulating device is controlled to adjust the flow rate of water flowing into the first pipe to the inlet of the indoor heating equipment and the inlet of the first channel, so that a portion of the water flows to the inlet of the indoor heating equipment and the other portion flows to the inlet of the first channel.

[0128] When a domestic water signal is received during heating, compared to the prior art where the flow regulation device controls the water flowing into the first pipe to flow entirely into the inlet of the first channel, the embodiment in this specification controls the flow regulation device to divert the water flowing into the first pipe to the inlet of the indoor heating equipment and the inlet of the first channel. This results in a portion of the water flowing into the indoor heating equipment and another portion flowing into the inlet of the first channel, thereby reducing the flow rate of hot water into the inlet of the first channel. This reduces the heat exchange between the hot water in the first channel and the domestic water in the second channel, lowering the temperature of the domestic water flowing out of the second channel. This prevents the domestic water from overheating, reducing the risk of scalding for users and improving the user experience.

[0129] When a domestic water signal is received during heating, the heating water circuit (including the water inlet to the indoor heating equipment) is not immediately shut off. Instead, a preliminary diversion is performed. By controlling the flow regulation device, the high-temperature water flowing out of the outlet of the first heat exchanger flows simultaneously to the indoor heating equipment and the first flow channel of the second heat exchanger. This preliminary diversion reduces the amount of water entering the first flow channel of the second heat exchanger, thereby reducing heat input at the source. This ensures that only a portion of the water flows into the first flow channel of the second heat exchanger to exchange heat with the domestic water flowing into the second flow channel of the second heat exchanger. This avoids a sudden spike in the temperature of the domestic water flowing out of the second flow channel of the second heat exchanger and severe overheating.

[0130] Moreover, when a domestic water signal is received during heating, the water is initially diverted, but the heating water circuit is not completely cut off. High-temperature water still flows through the indoor heating equipment, which avoids a sudden drop in indoor temperature and has a relatively small impact on heating comfort.

[0131] Step S20: Based on the domestic water outlet temperature and the domestic water set temperature, control the flow regulating device to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel; the domestic water outlet temperature is the temperature of the water flowing out of the outlet of the second flow channel.

[0132] After initial diversion, dynamic proportional adjustment is performed. Specifically, after controlling a portion of the water flowing into the first pipeline to flow to the inlet of the indoor heating equipment and another portion to flow to the inlet of the first flow channel, the flow regulating device can adjust the ratio between the flow rate of the water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, based on the domestic water outlet temperature and the domestic water set temperature.

[0133] That is, the flow regulating device is then used to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first channel, based on the temperature difference between the domestic water outlet temperature and the domestic water set temperature, so that the temperature of the domestic water flowing out of the second channel is close to the domestic water set temperature.

[0134] By adjusting the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first channel, the amount of hot water entering the first channel of the second heat exchanger is controlled, thereby precisely controlling the heat exchange of the second heat exchanger and ultimately stabilizing the domestic water outlet temperature near the set domestic water temperature.

[0135] The gas-fired water heater in the above embodiments can reduce the fluctuation of domestic water temperature, improve the user's constant temperature experience, ensure user water safety, and at the same time reduce the impact of domestic water use on indoor heating comfort, thus balancing the stability and comfort of the heating system.

[0136] In some embodiments of this specification, in step S10, the flow rate of a portion of the water flowing to the inlet of the indoor heating equipment is greater than the flow rate of another portion of the water flowing to the inlet of the first flow channel, wherein the flow rate of the other portion of the water is a preset flow rate.

[0137] In this embodiment, during the initial diversion, the flow regulating device can be controlled so that the flow rate of water flowing into the first pipeline to the inlet of the first channel is less than the flow rate diverted to the inlet of the indoor heating equipment. That is, during the initial diversion, the flow regulating device is controlled to allow a small amount of water to flow into the inlet of the first channel. The flow rate of water flowing into the inlet of the first channel can be a preset flow rate. This preset flow rate can be set based on experience. The preset flow rate is usually set based on a safety threshold (empirical value) to ensure that the domestic water will not exceed the temperature limit even under high water temperature conditions. By setting the flow rate flowing into the inlet of the first channel during the initial diversion to the preset flow rate, it can be further ensured that the domestic water will not exceed the temperature limit, guaranteeing the user's water safety.

[0138] In some embodiments of this specification, the flow regulating device may include a three-way valve. In one embodiment, a stepper motor can be used to drive the three-way valve to regulate the flow rate diverted to the indoor heating equipment and the first flow channel. During initial diversion, the stepper motor can be controlled to move a preset number of steps, thereby driving the three-way valve to actuate, allowing a small amount of water to flow into the inlet of the first flow channel. At this point, the water flow rate into the inlet of the first flow channel is very low. Initial diversion is equivalent to giving the three-way valve an initial value, allowing some of the water flowing into the first pipeline to quickly flow into the inlet of the first flow channel. In this embodiment, the preset flow rate may correspond to the preset number of initial steps. In one embodiment, the preset number of steps is 20 steps, 30 steps, or 50 steps, etc. The preset number of steps can be set according to actual conditions.

[0139] In some embodiments of this specification, step S10 specifically includes: controlling the flow regulating device to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel based on the temperature difference between the heating outlet water temperature and the domestic water set temperature and / or the domestic water flow rate at the inlet of the second flow channel, so that a portion of the water flows to the inlet of the indoor heating equipment and another portion flows to the inlet of the first flow channel; the flow rate of the other portion of water flowing to the inlet of the first flow channel is negatively correlated with the temperature difference, and / or the flow rate of the other portion of water flowing to the inlet of the first flow channel is positively correlated with the domestic water flow rate; the heating outlet water temperature is the temperature of the water flowing out of the outlet of the first heat exchanger.

[0140] In this embodiment, the initial flow rate of water diverted to the inlet of the first flow channel can be determined based on the temperature difference between the heating outlet water temperature and the set domestic water temperature and / or the domestic water flow rate at the inlet of the second flow channel. Then, the flow regulating device can be controlled to adjust the flow rate of water flowing into the first pipeline to the inlet of the first flow channel as the initial flow rate. In other words, in this embodiment, the initial flow rate of water diverted to the inlet of the first flow channel during the initial diversion can be determined based on the temperature difference between the heating outlet water temperature and the set domestic water temperature and / or the domestic water flow rate at the inlet of the second flow channel.

[0141] In one embodiment, the initial flow rate can be determined based on the temperature difference between the heating outlet water temperature and the domestic water set temperature. The heating outlet water temperature is higher than the domestic water set temperature. The greater the temperature difference between the two, the higher the heating outlet water temperature. To avoid overheating, a small amount of high-temperature water can flow into the inlet of the first flow channel. That is, the greater the temperature difference between the heating outlet water temperature and the domestic water set temperature, the smaller the initial flow rate. The two are negatively correlated.

[0142] In another embodiment, the initial flow rate of water diverted to the inlet of the first channel during initial diversion can be determined based on the domestic water flow rate flowing into the inlet of the second channel. A higher domestic water flow rate into the inlet of the second channel indicates a greater heat requirement for domestic water use. To ensure the domestic water outlet temperature is close to the set domestic water temperature, slightly more high-temperature water can flow into the inlet of the first channel. Therefore, a higher domestic water flow rate into the inlet of the second channel results in a higher initial flow rate, and the two are positively correlated.

[0143] In another embodiment, the initial flow rate of water diverted to the inlet of the first flow channel during initial diversion can be determined by considering both the temperature difference between the heating outlet water temperature and the domestic water set temperature, and the domestic water flow rate flowing into the inlet of the second flow channel. For example, if the temperature difference between the heating outlet water temperature and the domestic water set temperature is large and the domestic water flow rate flowing into the inlet of the second flow channel is small, a very low initial flow rate can be set. Conversely, if the temperature difference between the heating outlet water temperature and the domestic water set temperature is small and the domestic water flow rate flowing into the inlet of the second flow channel is large, a larger initial flow rate can be set.

[0144] In some embodiments of this specification, step S10 specifically includes: when a domestic water signal is received in the heating state, determining whether the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than a first preset temperature difference; the heating outlet water temperature is the temperature of the water flowing out of the outlet of the first heat exchanger; the first preset temperature difference is greater than zero; when it is determined that the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than the first preset temperature difference, controlling the flow regulating device to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that a portion of the water flows to the inlet of the indoor heating equipment and the other portion of the water flows to the inlet of the first flow channel.

[0145] In this embodiment, when a domestic water signal is received during heating, it can first be determined whether the temperature difference between the heating outlet water temperature and the set domestic water temperature is greater than a first preset temperature difference. The first preset temperature difference can be set according to actual conditions. In one embodiment, the first preset temperature difference can be set to 10℃ to 20℃, for example, it can be set to 15℃. When the temperature difference between the heating outlet water temperature and the set domestic water temperature is large, that is, when the heating outlet water temperature is high, preliminary diversion is performed, and the flow regulating device is controlled to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel. In this embodiment, by judging the temperature difference threshold, high-temperature scenarios can be identified, and preliminary diversion is only performed when the temperature is high, forming an intelligent diversion mechanism that starts on demand, taking into account both safety and economy.

[0146] In some embodiments of this specification, step S10 specifically includes: when a domestic water signal is received in the heating state, determining whether the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than a first preset temperature difference; the heating outlet water temperature is the temperature of the water flowing out of the outlet of the first heat exchanger; the first preset temperature difference is greater than zero; when it is determined that the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than the first preset temperature difference, controlling the burner to stop burning or maintain a stopped burning state; controlling the flow regulating device to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that a portion of the water flows to the inlet of the indoor heating equipment and the other portion of the water flows to the inlet of the first flow channel.

[0147] In this embodiment, when a domestic water signal is received during heating, it can first be determined whether the temperature difference between the heating outlet water temperature and the set domestic water temperature is greater than a first preset temperature difference. In one embodiment, the first preset temperature difference can be set to 10℃ to 20℃, for example, it can be set to 15℃. When the temperature difference between the heating outlet water temperature and the set domestic water temperature is large, that is, when the heating outlet water temperature is high, the burner is controlled to stop combustion or remain in a state of not burning, and preliminary diversion is performed. The flow regulating device is controlled to regulate the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel. In this embodiment, high-temperature scenarios can be identified by judging the temperature difference threshold. In high-temperature scenarios, in order to avoid domestic water overheating, on the one hand, the burner is controlled to shut down or remain in a state of not burning, and on the other hand, preliminary diversion is performed. Through the coordinated control of heat source and diversion, the risk of overheating is reduced to almost zero.

[0148] In some embodiments of this specification, after determining whether the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than a first preset temperature difference, the method further includes: step S30, if it is determined that the temperature difference between the heating outlet water temperature and the domestic water set temperature is not greater than the first preset temperature difference, controlling the burner to start combustion or maintain combustion state, and controlling the flow regulating device to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that all the water flowing into the first pipeline flows to the inlet of the first flow channel.

[0149] In this embodiment, after determining whether the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than a first preset temperature difference, if the temperature difference is not greater than the first preset temperature difference, it indicates that the heating water temperature is not high and overheating is unlikely. At this time, the burner is controlled to start combustion or maintain combustion, and the flow regulating device is controlled so that all the water flowing into the first pipeline flows to the inlet of the first flow channel. When the temperature of the heating water flowing out of the outlet of the first heat exchanger is low, by controlling the burner to ignite and controlling the flow regulating device to fully switch to the inlet of the first flow channel, since the heating outlet water temperature is low, overheating will not occur. Moreover, by controlling the burner to ignite and fully switching the flow regulating device, the domestic water temperature flowing out of the second flow channel can quickly reach the domestic water set temperature, reducing user waiting time and improving user experience.

[0150] In some embodiments of this specification, after step S30, the method may further include: determining the target power of the gas-fired water heater based on the current required load, and controlling the burner to burn according to the target power to heat the first heat exchanger.

[0151] When the heating water outlet temperature is low, after controlling the burner to ignite and fully switching the flow regulating device to the inlet of the first flow channel, constant temperature regulation can be performed based on the current required load. Specifically, the target power of the gas-fired water heater can be determined based on the current required load, and the burner can be controlled to ignite and heat the first heat exchanger based on the target power. The current required load refers to the heat load required to heat the domestic water flowing into the second flow channel to the set domestic water temperature. Performing constant temperature regulation after fully switching off the flow channel allows the domestic water outlet temperature to stabilize near the set domestic water temperature as quickly as possible, improving the user's experience of constant water temperature.

[0152] In some embodiments of this specification, after step S20, the method may further include: determining whether the domestic water usage time has reached a preset time; if the domestic water usage time has not reached the preset time, determining whether the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than a second preset temperature difference; the second preset temperature difference is greater than zero; if the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than the second preset temperature difference, returning to step S20.

[0153] In this embodiment, upon receiving a domestic water signal during heating, a preliminary diversion is first performed. This involves controlling the flow regulating device to adjust the flow rate of heating water flowing into the first pipeline to the indoor heating equipment and the inlet of the first flow channel, ensuring that only a portion of the water flows into the inlet of the first flow channel for heat exchange with the domestic water flowing into the second flow channel. Subsequently, the ratio of the water flow rate diverted to the indoor heating equipment and the inlet of the first flow channel can be fine-tuned based on the domestic water outlet temperature and the domestic water set temperature. After fine-tuning, it is determined whether the domestic water usage time has reached a preset duration. If the preset duration has not been reached, it is determined whether the temperature difference between the heating outlet temperature and the domestic water set temperature is greater than a second preset temperature difference. In one embodiment, the preset duration can be set to 40 to 80 seconds, for example, 60 seconds. In one embodiment, the second preset temperature difference can be set to 8°C to 18°C, for example, 12°C. If the temperature difference between the heating outlet water temperature and the domestic water set temperature is still large, it indicates that the heating outlet water temperature is still high, meaning the temperature reduction is insufficient to eliminate the risk of overheating. Fine-tuning can continue; that is, the process can return to step S20 to adjust the flow rate control device based on the domestic water outlet water temperature and the domestic water set temperature. In the initial stage (when the heating outlet water temperature and the domestic water set temperature are greater than the first preset temperature difference), the burner is in a shut-off state, and the high-temperature heating water is initially diverted to prevent overheating. However, in the later stages, due to heat exchange with the domestic water, the heating water temperature naturally decreases. At this point, it is necessary to determine whether the heating water temperature is still very high (whether the temperature difference is greater than the second preset temperature difference) and divert the flow to prevent overheating. If so, fine-tuning continues. Furthermore, considering that the water temperature decreases less when the domestic water usage time has not reached the preset time, the heating water temperature is still relatively high, which may necessitate further fine-tuning through flow diversion. Therefore, it is possible to determine whether the temperature difference exceeds a second preset temperature difference only within a preset time period for domestic water usage, and then determine whether to continue fine-tuning based on the judgment result. In this way, when the heating water outlet temperature is high within the preset time period for domestic water usage, the flow regulating device can continuously fine-tune the water flow rate at the inlet of the first flow channel to avoid directly switching to the domestic water side and causing overheating.

[0154] In some embodiments of this specification, the method may further include: step S40, when it is determined that the domestic water usage time has reached a preset time or when it is determined that the temperature difference between the heating outlet water temperature and the domestic water set temperature is not greater than a second preset temperature difference, controlling the flow regulating device to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that all the water flowing into the first pipeline flows to the inlet of the first flow channel.

[0155] In one embodiment, when the domestic water usage time reaches a preset duration, indicating that the usage time has been relatively long, the burner is shut off and the heating water and domestic water continue to exchange heat, resulting in a low heating water temperature and virtually eliminating the possibility of domestic water overheating. Instead, all heat needs to be concentrated to maintain the domestic water temperature. Therefore, when the domestic water usage time reaches the preset duration, the system can be completely switched to the domestic water side, i.e., the flow regulation device can be controlled to ensure that all water flowing into the first pipeline flows to the inlet of the first flow channel to meet the heat demand for domestic water.

[0156] In another embodiment, if the temperature difference between the heating outlet water temperature and the set domestic water temperature is not greater than a second preset temperature difference when the domestic water usage time is within a preset period, it indicates that the heating outlet water temperature is low and there is essentially no overheating of the domestic water. Instead, all heat needs to be concentrated to maintain the domestic water temperature. Therefore, if the domestic water usage time has not reached the preset period and the temperature difference between the heating outlet water temperature and the set domestic water temperature is not greater than the second preset temperature difference, the flow can be completely switched to the domestic water side. That is, the flow regulation device is controlled so that all the water flowing into the first pipeline flows to the inlet of the first flow channel to meet the heat demand of domestic water.

[0157] By employing the above method, when the heating outlet water temperature is not high (the domestic water usage time reaches the preset duration or the temperature difference between the heating outlet water temperature and the domestic water set temperature is not greater than the second preset temperature difference), the flow regulating device is fully switched to the domestic water side (i.e., all water flowing into the first pipe flows to the inlet of the first flow channel). This concentrates heat to maintain the domestic water temperature, causing the domestic water outlet temperature to rise to near the domestic water set temperature. Furthermore, when the heating outlet water temperature is not high, switching entirely to the domestic water side can cut off the heating circuit, preventing lower-temperature heating water from flowing into the indoor heating equipment and causing a drop in indoor temperature, thus affecting heating comfort.

[0158] In some embodiments of this specification, after step S40, the method may further include: step S50, controlling the circulation pump to start or stop according to the domestic water outlet temperature and the domestic water set temperature, so that the domestic water outlet temperature is close to the domestic water set temperature.

[0159] Specifically, after switching entirely to the domestic water side, the circulation pump can be started or stopped based on the domestic water outlet temperature and the set domestic water temperature. This allows water flowing into the first pipeline to either flow into the first flow channel or not, thereby regulating the water flow rate in the first pipeline to ensure the domestic water outlet temperature is close to the set domestic water temperature. After switching entirely to the domestic water side, the flow rate can be controlled by starting and stopping the circulation pump, further regulating the temperature to ensure the domestic water outlet temperature is close to the set domestic water temperature, thus improving the user's water experience.

[0160] In some embodiments of this specification, step S50 may specifically include: controlling the circulation pump to stop working when the domestic water outlet temperature is higher than the domestic water set temperature; and controlling the circulation pump to start working when the domestic water outlet temperature is not higher than the domestic water set temperature. In this embodiment, when the domestic water outlet temperature is higher than the domestic water set temperature, stopping the circulation pump is equivalent to cutting off the flow of heat source water, and the heat exchange between the heating water in the first flow channel and the domestic water in the second flow channel slows down or stops; when the temperature is lower than the set value, the circulation pump is restarted, allowing the heating water to flow back through the first flow channel of the second heat exchanger to heat the domestic water in the second flow channel.

[0161] In some embodiments of this specification, step S50 may specifically include: when the domestic water outlet temperature is higher than the domestic water set temperature and the temperature difference between the two is greater than a first difference, controlling the circulation pump to stop working for a first preset time; when the domestic water set temperature is higher than the domestic water outlet temperature and the temperature difference between the two is greater than a second difference, controlling the circulation pump to start working for a second preset time.

[0162] In this embodiment, when the outlet temperature of the domestic water is higher than the set domestic water temperature and the temperature difference between the two is greater than a first difference value, the circulation pump is controlled to stop working for a first preset duration. The first difference value can be set to 1 degree Celsius to 3 degrees Celsius, for example, 2 degrees Celsius. The first preset duration can be set according to actual conditions, for example, 3 seconds to 20 seconds. After the circulation pump stops working for the first preset duration, the outlet temperature of the domestic water decreases to approach the set domestic water temperature. When the set domestic water temperature is higher than the outlet temperature and the temperature difference between the two is greater than a second difference value, the circulation pump is controlled to start working for a second preset duration. After the circulation pump starts working for the second preset duration, the outlet temperature of the domestic water increases to approach the set domestic water temperature. Through this method, the fluctuation of the outlet domestic water temperature can be reduced while avoiding excessively frequent start-stop of the circulation pump, thus improving the user's constant temperature experience.

[0163] In some embodiments of this specification, after step S40 or step S50, the method may further include: determining whether ignition conditions are met based on the heating outlet water temperature, the domestic water set temperature, and the domestic water flow rate at the inlet of the second flow channel; if the ignition conditions are met, controlling the burner to start combustion; determining the target power based on the current required load, and controlling the burner to burn according to the target power to heat the first heat exchanger.

[0164] After the flow regulating device is fully switched to the domestic water side, or after controlling the circulation pump to start or stop based on the domestic water outlet temperature and the domestic water set temperature to bring the domestic water outlet temperature close to the domestic water set temperature, it can be determined whether ignition is required. Specifically, the ignition conditions can be determined based on the heating water outlet temperature, the domestic water set temperature, and the domestic water flow rate at the inlet of the second flow channel. If the heating water outlet temperature is insufficient to maintain heating the domestic water to the domestic water set temperature, it is determined that the ignition conditions are met. If the ignition conditions are met, the burner is controlled to start combustion. Afterwards, constant temperature regulation is performed based on the current required load. Specifically, the target power of the gas-fired water heater can be determined based on the current required load, and the burner is controlled to heat the first heat exchanger based on the target power. The current required load refers to the heat load required to heat the domestic water flowing into the second flow channel to the domestic water set temperature. In this way, when the heating water heat is insufficient to meet the domestic hot water demand, the burner can be controlled to meet the user's domestic hot water needs.

[0165] In some embodiments of this specification, step S10 may specifically include: when a domestic water signal is received in the heating state, determining whether the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than a first preset temperature difference; the heating outlet water temperature is the temperature of the water flowing out of the outlet of the first heat exchanger; the first preset temperature difference is greater than zero; when it is determined that the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than the first preset temperature difference, controlling the burner to burn according to the minimum power; controlling the flow regulating device to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that a portion of the water flows to the inlet of the indoor heating equipment and the other portion of the water flows to the inlet of the first flow channel.

[0166] In this embodiment, when a domestic water signal is received during heating, it can first be determined whether the temperature difference between the heating outlet water temperature and the set domestic water temperature is greater than a first preset temperature difference. In one embodiment, the first preset temperature difference can be set to 10℃ to 20℃, for example, it can be set to 15℃. When the temperature difference between the heating outlet water temperature and the set domestic water temperature is large, that is, when the heating outlet water temperature is high, the burner is controlled to ignite according to the minimum power, and preliminary diversion is performed. The flow regulating device is controlled to regulate the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel. Here, the minimum power refers to the minimum power at which the gas water heater can start combustion. From a thermodynamic point of view, minimum power combustion is equivalent to a heat buffer, which avoids the continuous generation of high-temperature water and prevents ignition delay caused by the complete cooling of the burner. The rise from minimum power to target power is faster than cold start, which is crucial for the water experience. In this embodiment, high-temperature scenarios can be identified by judging the temperature difference threshold. In high-temperature scenarios, in order to avoid domestic water overheating, the burner is controlled to ignite according to the minimum power, and preliminary diversion is performed on the other hand. By coordinating the control of the heat source and the flow divider, the risk of overheating is greatly reduced. Furthermore, by controlling the burner to operate at minimum power instead of shutting it down, repeated start-ups and shutdowns are avoided, thus extending the lifespan of burner components. In addition, compared to the process from ignition to stable combustion, the gas-fired water heater in this embodiment does not require ignition to reach the target power from minimum power, resulting in faster combustion stabilization, improved combustion response and stability, and a better user experience.

[0167] In some embodiments of this specification, after determining whether the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than a first preset temperature difference, the method further includes: if it is determined that the temperature difference between the heating outlet water temperature and the domestic water set temperature is not greater than the first preset temperature difference, controlling the burner to start combustion or maintain combustion state, and controlling the flow regulating device to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that all the water flowing into the first pipeline flows to the inlet of the first flow channel.

[0168] In this embodiment, after determining whether the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than a first preset temperature difference, if the temperature difference is not greater than the first preset temperature difference, it indicates that the heating water temperature is not high and overheating is unlikely. At this time, the burner is controlled to start combustion or maintain combustion, and the flow regulating device is controlled so that all the water flowing into the first pipeline flows to the inlet of the first flow channel. When the temperature of the heating water flowing out of the outlet of the first heat exchanger is low, by controlling the burner to ignite and controlling the flow regulating device to fully switch to the inlet of the first flow channel, since the heating outlet water temperature is low, overheating will not occur. Moreover, by controlling the burner to ignite and fully switching the flow regulating device, the domestic water temperature flowing out of the second flow channel can quickly reach the domestic water set temperature, reducing user waiting time and improving user experience.

[0169] In some embodiments of this specification, after controlling the flow regulating device to regulate the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that all the water flowing into the first pipeline flows to the inlet of the first flow channel, the method may further include: determining the target power of the gas-fired water heater according to the current required load, and controlling the burner to burn according to the target power to heat the first heat exchanger.

[0170] When the heating water outlet temperature is low, after controlling the burner combustion and fully switching the flow regulating device to the inlet of the first flow channel, constant temperature regulation can be performed according to the current required load. Specifically, the target power of the gas-fired water heater can be determined based on the current required load, and the burner combustion can be controlled according to the target power to heat the first heat exchanger. The current required load refers to the heat load required to heat the domestic water flowing into the second flow channel to the set domestic water temperature. Performing constant temperature regulation after fully switching off the flow channel allows the domestic water outlet temperature to stabilize near the set domestic water temperature as quickly as possible.

[0171] In some embodiments of this specification, step S20 may specifically include: controlling the burner to burn based on the temperature difference between the heating water outlet temperature and the domestic water set temperature, so that the temperature difference between the heating water outlet temperature and the domestic water set temperature is close to a second preset temperature difference; and controlling the flow regulating device to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, based on the domestic water outlet temperature and the domestic water set temperature, until all the water flowing into the first pipeline flows to the inlet of the first flow channel.

[0172] In this embodiment, when the temperature difference between the heating outlet water temperature and the domestic water set temperature is determined to be greater than a first preset temperature difference, after controlling the burner to ignite and perform initial flow diversion according to the minimum power, the burner is then controlled to ignite based on the temperature difference between the heating outlet water temperature and the domestic water set temperature, so that the temperature difference between the heating outlet water temperature and the domestic water set temperature approaches a second preset temperature difference. The second preset temperature difference can be set to 8-18℃, for example, it can be set to 12℃. In one embodiment, if the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than the second preset temperature difference, it indicates that the heating outlet water temperature is high. In this case, the burner's combustion power is reduced to lower the heating outlet water temperature. If the temperature difference between the heating outlet water temperature and the domestic water set temperature is not greater than the second preset temperature difference, it indicates that the heating outlet water temperature is low. In this case, the burner's combustion power is increased to raise the heating outlet water temperature. While controlling the burner's combustion based on the temperature difference between the heating water outlet temperature and the domestic water set temperature, the flow regulating device also adjusts the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, based on the domestic water outlet temperature and the domestic water set temperature. That is, while controlling the burner's combustion based on the temperature difference between the heating water outlet temperature and the domestic water set temperature, the flow rate of water diverted to the first flow channel is dynamically proportionally adjusted based on the domestic water outlet temperature and the domestic water set temperature. Controlling the burner's combustion based on the temperature difference between the heating water outlet temperature and the domestic water set temperature is to ensure that the heating water outlet temperature is at a higher temperature to meet the user's hot water needs. At this time, the flow regulating device can be used to adjust the flow rate of water flowing into the first flow channel to make the domestic water outlet temperature close to the domestic water set temperature. The above steps are repeated until the water is completely switched to the domestic water side, that is, until all the water flowing into the first pipeline flows to the inlet of the first flow channel. In this way, after receiving the domestic water signal in heating mode, if the heating outlet water temperature is very high, the burner is controlled to ignite and perform initial diversion according to the minimum power. Then, the power of the burner is adjusted to keep the heating outlet water temperature at a stable and high level. At the same time, the water flow rate diverted to the first flow channel is dynamically adjusted according to the domestic water outlet water temperature and the domestic water set temperature, so that the domestic water outlet water temperature is stabilized near the domestic water set temperature, until it is fully switched to the domestic water side. This can greatly reduce the fluctuation of the outlet water temperature and improve the user's constant temperature experience.

[0173] In some embodiments of this specification, after step S20, the method may further include: determining the target power of the gas-fired water heater based on the current required load, and controlling the burner to burn according to the target power to heat the first heat exchanger.

[0174] Upon receiving a domestic water supply signal during heating mode, if the heating outlet water temperature is high, the burner is controlled to ignite and initially divert the water flow according to the minimum power setting. The burner power is then adjusted to maintain a stable, high heating outlet water temperature. Simultaneously, the water flow rate diverted to the first channel is dynamically adjusted based on the domestic water outlet temperature and the set domestic water temperature, ensuring the domestic water outlet temperature remains stable near the set domestic water temperature until the entire flow is switched to the domestic water side. Afterward, the target power of the gas-fired water heater can be determined based on the current required load, and the burner is controlled to ignite and heat the first heat exchanger for constant temperature regulation. Through dynamic matching control of load demand and combustion power, the gas-fired water heater evolves from a safe overheat protection mode to a high-efficiency constant temperature mode.

[0175] Next, the specific implementation method of step S20 will be described.

[0176] In some embodiments of this specification, step S20 may specifically include: when the domestic water outlet temperature is higher than the domestic water set temperature, controlling the flow regulating device to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, thereby reducing the flow rate diverted to the inlet of the first flow channel; when the domestic water outlet temperature is lower than the domestic water set temperature, controlling the flow regulating device to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, thereby increasing the flow rate diverted to the inlet of the first flow channel.

[0177] In this embodiment, when the domestic water outlet temperature is higher than the domestic water set temperature, the flow regulating device can be controlled to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, so that the flow rate diverted to the inlet of the first flow channel is reduced, thereby lowering the domestic water outlet temperature and making the domestic water outlet temperature close to the domestic water set temperature.

[0178] When the domestic water outlet temperature is lower than the domestic water set temperature, the flow regulating device can be controlled to adjust the ratio of the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the zero flow rate diverted to the inlet of the first flow channel, thereby increasing the flow rate diverted to the inlet of the first flow channel, thereby raising the domestic water outlet temperature and making the domestic water outlet temperature close to the domestic water set temperature.

[0179] In some embodiments of this specification, step S20 may specifically include: determining whether the domestic water outlet temperature is less than the difference between the domestic water set temperature and the fifth preset temperature difference; the fifth preset temperature difference is greater than zero; if it is determined that the domestic water outlet temperature is less than the difference between the domestic water set temperature and the fifth preset temperature difference, controlling the flow regulating device to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, so that the flow rate to the inlet of the first flow channel increases by a first magnitude.

[0180] In this embodiment, when dynamically adjusting the water flow rate, it can be determined whether the temperature difference between the set domestic water temperature and the domestic water outlet temperature is less than a fifth preset temperature difference. The fifth preset temperature difference is greater than zero. In one embodiment, the fifth preset temperature difference can be set to 1°C to 3°C. For example, the fifth preset temperature difference can be set to 2°C. When the set domestic water temperature is more than 2°C higher than the domestic water outlet temperature, it indicates that the domestic water outlet temperature is low. With the heat exchange of the heating water, the domestic water outlet temperature will continue to decrease, so it is necessary to increase the flow rate to the inlet of the first flow channel. In one embodiment, when the domestic water outlet temperature is less than the difference between the set domestic water temperature and the fifth preset temperature difference, the flow rate regulating device is controlled to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, so that the flow rate to the inlet of the first flow channel increases by a first magnitude. In one embodiment, the flow rate regulating device may include a three-way valve. A stepper motor drives the three-way valve to operate. When the domestic water outlet temperature is less than the set domestic water temperature minus 2°C, the three-way valve can be controlled to move 6 steps towards the domestic water side. In this embodiment, when the domestic water outlet temperature is lower than the domestic water set temperature, the flow regulating device can be controlled to increase the flow rate of the heating water flowing to the domestic water outlet by a first magnitude. This is because as heat exchange proceeds, the temperature of the heating water will continue to drop, and the domestic water outlet temperature will continue to decrease. Therefore, it is necessary to increase the flow rate to the inlet of the first flow channel to raise the domestic water outlet temperature and stabilize it near the domestic water set temperature.

[0181] In some embodiments of this specification, after determining whether the domestic water outlet temperature is less than the difference between the domestic water set temperature and the fifth preset temperature difference, the method may further include: if it is determined that the domestic water outlet temperature is not less than the difference between the domestic water set temperature and the fifth preset temperature difference, determining whether the domestic water outlet temperature is less than the domestic water set temperature; if it is determined that the domestic water outlet temperature is less than the domestic water set temperature, controlling the flow regulating device to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, such that the flow rate to the inlet of the first flow channel increases by a second magnitude, the second magnitude being less than the first magnitude.

[0182] In this embodiment, when dynamically adjusting the water flow rate, the system determines whether the domestic water outlet temperature is lower than the domestic water set temperature if the temperature difference between the domestic water set temperature and the domestic water outlet temperature is not less than a fifth preset temperature difference. In one embodiment, the fifth preset temperature difference can be set to 1°C to 3°C. For example, the fifth preset temperature difference can be set to 2°C. If the domestic water set temperature is higher than the domestic water outlet temperature and the temperature difference between them is not greater than the fifth preset temperature difference, it indicates that the domestic water outlet temperature is slightly lower than the domestic water set temperature. As the heating water undergoes heat exchange, the domestic water outlet temperature will continue to decrease, thus requiring an increase in the flow rate to the inlet of the first flow channel. In one embodiment, if the domestic water outlet temperature is lower than the domestic water set temperature and greater than or equal to the difference between the domestic water set temperature and the fifth preset temperature difference, the flow rate regulating device adjusts the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, thereby increasing the flow rate to the inlet of the first flow channel by a second magnitude. The second magnitude is less than the first magnitude. In one embodiment, the flow regulating device may include a three-way valve. A stepper motor drives the three-way valve to operate. When the domestic water outlet temperature is lower than the set domestic water temperature but greater than or equal to the set domestic water temperature minus 2°C, the three-way valve can be controlled to move four steps towards the domestic water side. In this embodiment, when the domestic water outlet temperature is slightly lower than the set domestic water temperature, the flow regulating device can be controlled to increase the flow rate of heating water flowing towards the domestic water side by a second magnitude, thereby raising the domestic water outlet temperature and stabilizing it near the set domestic water temperature.

[0183] In some embodiments of this specification, after determining whether the domestic water outlet temperature is less than the domestic water set temperature, the method may further include: if the domestic water outlet temperature is not less than the domestic water set temperature, determining whether the domestic water outlet temperature is less than the sum of the domestic water set temperature and a sixth preset temperature difference; the sixth preset temperature difference is greater than zero; if the domestic water outlet temperature is less than the sum of the domestic water set temperature and the sixth preset temperature difference, controlling the flow regulating device to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, such that the flow rate to the inlet of the first flow channel increases by a third magnitude, the third magnitude being less than the second magnitude.

[0184] In this embodiment, when dynamically adjusting the water flow rate, if the domestic water outlet temperature is determined to be not less than the domestic water set temperature, it is determined whether the domestic water outlet temperature is higher than the sum of the domestic water set temperature and the sixth preset temperature difference. The sixth preset temperature difference is greater than zero. In one embodiment, the sixth preset temperature difference can be set to 1℃ to 3℃; for example, it can be set to 2℃. In one embodiment, if the domestic water outlet temperature is greater than or equal to the domestic water set temperature but less than the domestic water set temperature plus 2℃, then when the domestic water outlet temperature is slightly higher than the domestic water set temperature, the heating water temperature will decrease as heat exchange continues, which will lead to a decrease in the domestic water outlet temperature. To avoid the domestic water outlet temperature decreasing too quickly or too much, the flow regulating device can be controlled to increase the water flow rate towards the first flow channel inlet by a third amplitude. The third amplitude is less than the second amplitude. In one embodiment, the flow regulating device may include a three-way valve, which is driven by a stepper motor. If the domestic water outlet temperature is not less than the domestic water set temperature but less than the domestic water set temperature plus 2℃, the three-way valve can be controlled to move two steps towards the domestic water side. In this embodiment, when the domestic water outlet temperature is slightly higher than the domestic water set temperature, the flow regulating device can be controlled to increase the flow rate of the heating water flowing to the domestic water outlet by a third magnitude, so as to raise the domestic water outlet temperature and stabilize it near the domestic water set temperature.

[0185] In some embodiments of this specification, step S20 may specifically include: determining whether the domestic water outlet temperature is greater than the sum of the domestic water set temperature and the third preset temperature difference; the third preset temperature difference is greater than zero; if it is determined that the domestic water outlet temperature is greater than the sum of the domestic water set temperature and the third preset temperature difference, controlling the flow regulating device to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, so that the flow rate to the inlet of the first flow channel is reduced.

[0186] In this embodiment, when dynamically adjusting the water flow rate, it can be determined whether the domestic water outlet temperature is greater than the sum of the domestic water set temperature and the third preset temperature difference. The third preset temperature difference can be set to 2℃ to 6℃, for example, 4℃. When the temperature difference between the domestic water outlet temperature and the domestic water set temperature is greater than 4℃, the flow regulating device can be controlled to adjust the ratio of the flow rate diverted to the inlet of the indoor heating equipment to the flow rate diverted to the inlet of the first flow channel, thereby reducing the flow rate to the inlet of the first flow channel. In one embodiment, the flow regulating device may include a three-way valve driven by a stepper motor. For example, when the temperature difference between the domestic water outlet temperature and the domestic water set temperature is greater than 4℃, the stepper motor can be used to control the three-way valve to move 1-3 steps towards the heating side to reduce the water flow to the domestic water side. Through this method, when the domestic water outlet temperature exceeds the domestic water set temperature by a significant amount, the water flow to the heating system can be reduced to lower the domestic water outlet temperature.

[0187] In some embodiments of this specification, after determining whether the domestic water outlet temperature is greater than the sum of the domestic water set temperature and the third preset temperature difference, the method may further include: if it is determined that the domestic water outlet temperature is not greater than the sum of the domestic water set temperature and the third preset temperature difference, determining whether the domestic water outlet temperature is greater than the sum of the domestic water set temperature and the fourth preset temperature difference; the fourth preset temperature difference is greater than zero and less than the third preset temperature difference; if it is determined that the domestic water outlet temperature is greater than the sum of the domestic water set temperature and the fourth preset temperature difference, controlling the flow regulating device to maintain a constant ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, so that the flow rate to the inlet of the first flow channel remains constant.

[0188] In this embodiment, when it is determined that the temperature of the domestic water outlet is not greater than the third preset temperature difference from the set temperature of the domestic water, it is judged whether the temperature difference between the two is greater than the fourth preset temperature difference. The fourth preset temperature difference is greater than zero and less than the third preset temperature difference. In one embodiment, the fourth preset temperature difference can be set to 1°C to 3°C. For example, the third preset temperature difference can be set to 4°C and the fourth preset temperature difference can be set to 2°C. When the temperature of the domestic water outlet is not greater than the third preset temperature difference and greater than the fourth preset temperature difference from the set temperature of the domestic water, the flow regulating device is controlled to keep the ratio between the flow rate diverted to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel unchanged, so that the flow rate flowing to the inlet of the first flow channel remains unchanged. In one embodiment, the flow regulating device may include a three-way valve. When the temperature difference between the temperature of the domestic water outlet and the set temperature of the domestic water is greater than 2°C and not greater than 4°C, the three-way valve can be controlled to maintain its current position. In this embodiment, when the temperature of the domestic water outlet is slightly higher than the set temperature of the domestic water, the water flow rate of the heating water flowing to the domestic side can be kept unchanged. This is because as heat exchange proceeds, the temperature of the heating water will naturally decrease and the temperature of the domestic water outlet will correspondingly decrease. Therefore, keeping the current water flow rate unchanged can make the temperature of the domestic water outlet stable near the set temperature of the domestic water.

[0189] Please refer to Figure 5 , which shows the flowchart of step S20 in the embodiment of the present specification. As Figure 5 shown, in step S20, the following sub-steps are included. In this embodiment, the flow regulating device is a three-way valve, and a stepper motor is used to drive the three-way valve to act.

[0190] Step 1: Judge whether T2 < Ts - 2 is satisfied. If so, execute step 2; otherwise, execute step 3. Here, T2 is the temperature of the domestic water outlet and Ts is the set temperature of the domestic water.

[0191] Step 2: Control the three-way valve to move 6 steps towards the domestic water side.

[0192] Step 3: Judge whether T2 < Ts is satisfied. If so, execute step 4; otherwise, execute step 5.

[0193] Step 4: Control the three-way valve to move 4 steps towards the domestic water side.

[0194] Step 5: Judge whether T2 < Ts + 2 is satisfied. If so, execute step 6; otherwise, execute step 7.

[0195] Step 6: Control the three-way valve to move 2 steps towards the domestic water side. [[ID=二十六]]

[0196] Step 7: Judge whether T2 < Ts + 4 is satisfied. If so, execute step 8; otherwise, execute step 9.

[0197] Step 8: Control the three-way valve to maintain its current position.

[0198] Step 9: Move the three-way valve one step towards the heating side.

[0199] In some embodiments of this specification, after controlling the burner to burn according to the target power to heat the first heat exchanger, the method may further include: controlling the burner to stop burning when the heating outlet water temperature is greater than the sum of the domestic water set temperature and the first preset temperature difference.

[0200] In this embodiment, after controlling the burner to burn according to the target power for constant temperature regulation, the burner can be controlled to stop burning when the heating outlet water temperature is greater than the sum of the domestic water set temperature and the first preset temperature difference, so as to avoid overheating on the domestic water side.

[0201] Please refer to Figure 6 A flowchart illustrating the control method of a gas-fired water heater according to an embodiment of this specification is shown. Figure 6 As shown, the control method in this specific embodiment includes the following steps. In this embodiment, the flow regulating device is a three-way valve, which is driven by a stepper motor.

[0202] Step 1: Receive domestic water usage signals.

[0203] Step 2: Determine if T1 - Ts > Δt1. If yes, proceed to Step 3; otherwise, proceed to Step 4. Here, T1 is the heating outlet water temperature, i.e., the temperature of the water flowing out of the first heat exchanger. Ts is the domestic water set temperature. Δt1 is the first preset temperature difference, which can be set to, for example, 15℃.

[0204] Step 3: Control the burner to shut down or maintain the shut-off state. Proceed to Step 5.

[0205] Step 4: Control the burner to start combustion or maintain combustion, and control the three-way valve to move fully to the domestic water side. Skip to step 15.

[0206] Step 5: Control the three-way valve to move away from the heating side by a first preset number of steps. For example, the first preset number of steps can be 30 steps.

[0207] Step 6: Control the movement of the three-way valve based on the temperature difference between T2 and Ts. Wherein, T2 is the domestic water outlet temperature.

[0208] Step 7: Determine if the preset time for domestic water usage has been met. If yes, proceed to step 8; otherwise, proceed to step 9.

[0209] Step 8: Move all three-way valves to the domestic water side. Proceed to step 10.

[0210] Step 9: Determine if T1-Ts>△t2. △t2 is a second preset temperature difference, for example, it can be set to 12℃. If yes, return to step 6; otherwise, proceed to step 8.

[0211] Step 10: Determine if T2 > Ts. If yes, proceed to step 11; otherwise, proceed to step 12.

[0212] Step 11: Control the circulation pump to stop working. Proceed to step 13.

[0213] Step 12: Control the circulation pump to start working. Proceed to step 13.

[0214] Step 13: Determine whether the ignition conditions are met based on T1, Ts, and F. If yes, proceed to step 14; otherwise, return to step 10. Here, F is the flow rate of domestic water in the second flow channel.

[0215] Step 14: Control the burner to start combustion.

[0216] Step 15: Control the burner combustion according to the current required load to achieve constant temperature regulation.

[0217] Please refer to Figure 7 A flowchart illustrating the control method of a gas-fired water heater according to an embodiment of this specification is shown. Figure 7 As shown, the control method in this specific embodiment includes the following steps. In this embodiment, the flow regulating device is a three-way valve, which is driven by a stepper motor.

[0218] Step 1: Receive domestic water usage signals.

[0219] Step 2: Determine if T1 - Ts > Δt1. If yes, proceed to Step 3; otherwise, proceed to Step 4. Here, T1 is the heating outlet water temperature, i.e., the temperature of the water flowing out of the first heat exchanger. Ts is the domestic water set temperature. Δt1 is the first preset temperature difference, which can be set to, for example, 15℃.

[0220] Step 3: Control the burner combustion according to the minimum power. Proceed to Step 5.

[0221] Step 4: Control the burner to start combustion or maintain combustion, and control the three-way valve to move fully to the domestic water side. Skip to step 7.

[0222] Step 5: Control the three-way valve to move away from the heating side a second preset number of steps. The second preset number of steps is less than the first preset number of steps. For example, the first preset number of steps can be 25 steps.

[0223] Step 6: Adjust the burner's combustion power so that T1-Ts approaches Δt2; control the movement of the three-way valve based on the temperature difference between T2 and Ts until the three-way valve is fully moved to the domestic water side. Here, Δt2 is the second preset temperature difference, for example, it can be set to 12℃. T2 is the domestic water outlet temperature.

[0224] Step 7: Control the burner combustion according to the current required load to achieve constant temperature regulation.

[0225] This specification also provides a controller, which may include a processor and a memory for storing processor-executable instructions. When the processor executes the instructions, it implements the steps of the gas-fired water heater control method described in any of the above embodiments.

[0226] This specification also provides a gas-fired water heating device, which may include the controller described in the above embodiments. For example... Figures 1 to 3 As shown, the gas-fired water heater 10 may further include: a first heat exchanger 101, a burner 102, a first pipeline 103 and a second pipeline 104, a second heat exchanger 105, a flow regulating device 106, and a circulating pump 107. For a detailed description of the gas-fired water heater, please refer to the description in the above embodiments; further details will not be repeated here.

[0227] This specification also provides a heating system in its embodiments. The heating system may include the gas-fired water heater as described in any of the above embodiments. The heating system may also include indoor heating equipment. The inlet of the indoor heating equipment is connected to the outlet of the first heat exchanger via a first pipe, and the outlet of the indoor heating equipment is connected to the inlet of the first heat exchanger via a second pipe.

[0228] This specification also provides a computer storage medium based on a gas-fired water heater control method, wherein the computer storage medium stores computer program instructions that, when executed, implement the steps of the gas-fired water heater control method described in any of the above embodiments.

[0229] In this embodiment, the storage medium includes, but is not limited to, Random Access Memory (RAM), Read-Only Memory (ROM), cache, hard disk drive (HDD), or memory card. The memory can be used to store computer program instructions. The network communication unit can be an interface configured according to standards specified in the communication protocol for network connection communication.

[0230] In this embodiment, the specific functions and effects implemented by the program instructions stored in the computer storage medium can be explained by comparison with other embodiments, and will not be repeated here.

[0231] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. For details, please refer to the foregoing descriptions of the relevant processing embodiments; they will not be repeated here.

[0232] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0233] Obviously, those skilled in the art will understand that the modules or steps of the embodiments described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby storing them in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the embodiments of this specification are not limited to any particular combination of hardware and software.

[0234] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this specification should not be determined by reference to the above description, but rather by reference to the foregoing claims and the full scope of their equivalents.

[0235] The above description is merely a preferred embodiment of this specification and is not intended to limit this specification. Various modifications and variations can be made to the embodiments described herein by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this specification should be included within the scope of protection of this specification.

Claims

1. A control method for a gas-fired hot water device, characterized in that, The gas-fired water heater includes: a first heat exchanger; a burner for heating the first heat exchanger; a first pipeline and a second pipeline, the first pipeline for directing at least a portion of the water flowing from the outlet of the first heat exchanger to an indoor heating system, and the second pipeline for returning water flowing through the indoor heating system to the inlet of the first heat exchanger; and a second heat exchanger having a first flow channel and a second flow channel isolated from each other, the inlet of the first flow channel being connected to the first pipeline to allow at least a portion of the water in the first pipeline to flow into the inlet of the first flow channel, and the outlet of the first flow channel being connected to the second pipeline to allow water flowing out of the outlet of the first channel to flow into the second pipeline. The flow channel is used for circulating domestic water, and the water flowing through the first flow channel and the water flowing through the second flow channel can exchange heat; the flow regulating device is used to regulate the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel; the circulation pump is installed on the first pipeline or the second pipeline, and the circulation pump can be used to drive water flowing from the outlet of the indoor heating equipment into the second pipeline to flow through the first heat exchanger and then from the first pipeline to the inlet of the indoor heating equipment, and the circulation pump can also be used to drive water flowing from the outlet of the first flow channel into the second pipeline to flow through the first heat exchanger and then from the first pipeline to the inlet of the first flow channel; The control method includes: Step S10: When a domestic water signal is received during heating, the flow regulating device is controlled to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that a portion of the water flows to the inlet of the indoor heating equipment and the other portion flows to the inlet of the first flow channel. Step S20: Based on the domestic water outlet temperature and the domestic water set temperature, control the flow regulating device to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel; the domestic water outlet temperature is the temperature of the water flowing out of the outlet of the second flow channel.

2. The control method for a gas-fired hot water device according to claim 1, characterized in that, In step S10, the flow rate of the portion of water flowing to the inlet of the indoor heating equipment is greater than the flow rate of the other portion of water flowing to the inlet of the first flow channel, and the flow rate of the other portion of water is a preset flow rate. or, Step S10 specifically includes: Based on the temperature difference between the heating outlet water temperature and the set domestic water temperature and / or the domestic water flow rate at the inlet of the second flow channel, the flow regulating device controls the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that a portion of the water flows to the inlet of the indoor heating equipment and another portion flows to the inlet of the first flow channel; the flow rate of the other portion of water flowing to the inlet of the first flow channel is negatively correlated with the temperature difference, and / or, the flow rate of the other portion of water flowing to the inlet of the first flow channel is positively correlated with the domestic water flow rate; the heating outlet water temperature is the temperature of the water flowing out of the outlet of the first heat exchanger.

3. The control method for a gas-fired hot water device according to claim 1, characterized in that, Step S10 specifically includes: When a domestic water signal is received during heating mode, it is determined whether the temperature difference between the heating outlet water temperature and the set domestic water temperature is greater than a first preset temperature difference; the heating outlet water temperature is the temperature of the water flowing out of the outlet of the first heat exchanger; the first preset temperature difference is greater than zero. If the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than the first preset temperature difference, the flow regulating device is controlled to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that a part of the water flows to the inlet of the indoor heating equipment and the other part flows to the inlet of the first flow channel.

4. The control method for a gas-fired hot water device according to claim 1, characterized in that, Step S10 specifically includes: When a domestic water signal is received during heating mode, it is determined whether the temperature difference between the heating outlet water temperature and the set domestic water temperature is greater than a first preset temperature difference; the heating outlet water temperature is the temperature of the water flowing out of the outlet of the first heat exchanger; the first preset temperature difference is greater than zero. If the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than the first preset temperature difference, the burner is controlled to stop burning or maintain the stopped burning state; the flow regulating device is controlled to regulate the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that a part of the water flows to the inlet of the indoor heating equipment and the other part of the water flows to the inlet of the first flow channel.

5. The control method for a gas-fired hot water device according to claim 3 or 4, characterized in that, After determining whether the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than the first preset temperature difference, the method further includes: Step S30: If the temperature difference between the heating outlet water temperature and the domestic water set temperature is not greater than the first preset temperature difference, control the burner to start combustion or maintain combustion state, and control the flow regulating device to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that all the water flowing into the first pipeline flows to the inlet of the first flow channel.

6. The control method for a gas-fired hot water device according to claim 5, characterized in that, Following step S30, the method further includes: The target power of the gas-fired water heater is determined based on the current required load, and the burner is controlled to ignite and heat the first heat exchanger based on the target power.

7. The control method for a gas-fired hot water device according to claim 4, characterized in that, Following step S20, the following is also included: Determine whether the domestic water usage time has reached the preset time; If it is determined that the domestic water usage time has not reached the preset time, it is determined whether the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than a second preset temperature difference; the second preset temperature difference is greater than zero. If it is determined that the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than the second preset temperature difference, return to step S20.

8. The control method for a gas-fired hot water device according to claim 7, characterized in that, Also includes: Step S40: If it is determined that the domestic water usage time has reached the preset time or if it is determined that the temperature difference between the heating outlet water temperature and the domestic water set temperature is not greater than the second preset temperature difference, the flow regulating device is controlled to adjust the flow rate of the water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that all the water flowing into the first pipeline flows to the inlet of the first flow channel.

9. The control method for a gas-fired hot water device according to claim 8, characterized in that, Following step S40, the method further includes: Step S50: Control the circulation pump to start or stop according to the domestic water outlet temperature and the domestic water set temperature, so that the domestic water outlet temperature is close to the domestic water set temperature.

10. The control method for a gas-fired hot water device according to claim 9, characterized in that, Step S50 specifically includes: If the temperature of the domestic water outlet is higher than the set temperature of the domestic water, the circulation pump shall be stopped. When the temperature of the domestic water outlet is not higher than the set temperature of the domestic water, the circulation pump is controlled to start working.

11. The control method for a gas-fired hot water device according to claim 9, characterized in that, Step S50 specifically includes: If the temperature of the domestic water outlet is higher than the set temperature of the domestic water and the temperature difference between the two is greater than a first difference value, the circulation pump is controlled to stop working for a first preset time. When the set temperature of the domestic water is higher than the outlet temperature of the domestic water and the temperature difference between the two is greater than a second difference value, the circulation pump is controlled to start working for a second preset time.

12. The control method for a gas-fired hot water device according to claim 9, characterized in that, Following step S40 or step S50, the method further includes: Based on the heating water outlet temperature, the domestic water set temperature, and the domestic water flow rate at the inlet of the second flow channel, determine whether the ignition conditions are met. If the ignition conditions are met, the burner is controlled to start combustion; The target power of the gas-fired water heater is determined based on the current required load, and the burner is controlled to ignite and heat the first heat exchanger based on the target power.

13. The control method for a gas-fired hot water device according to claim 1, characterized in that, Step S10 specifically includes: When a domestic water signal is received during heating mode, it is determined whether the temperature difference between the heating outlet water temperature and the set domestic water temperature is greater than a first preset temperature difference; the heating outlet water temperature is the temperature of the water flowing out of the outlet of the first heat exchanger; the first preset temperature difference is greater than zero. If the temperature difference between the heating outlet water temperature and the domestic water set temperature is greater than the first preset temperature difference, the burner is controlled to burn according to the minimum power; the flow regulating device is controlled to adjust the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel, so that a part of the water flows to the inlet of the indoor heating equipment and the other part flows to the inlet of the first flow channel.

14. The control method for a gas-fired hot water device according to claim 13, characterized in that, Step S20 specifically includes: The burner is controlled to burn according to the temperature difference between the heating water outlet temperature and the domestic water set temperature, so that the temperature difference between the heating water outlet temperature and the domestic water set temperature is close to the second preset temperature difference; according to the domestic water outlet temperature and the domestic water set temperature, the flow regulating device is controlled to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, until all the water flowing into the first pipeline flows to the inlet of the first flow channel.

15. The control method for a gas-fired hot water device according to claim 14, characterized in that, Following step S20, the method further includes: The target power of the gas-fired water heater is determined based on the current required load, and the burner is controlled to ignite and heat the first heat exchanger based on the target power.

16. The control method for a gas-fired hot water device according to claim 1, characterized in that, Step S20 specifically includes: When the domestic water outlet temperature is higher than the domestic water set temperature, the flow regulating device is controlled to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, so that the flow rate diverted to the inlet of the first flow channel is reduced. When the domestic water outlet temperature is lower than the domestic water set temperature, the flow regulating device adjusts the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, thereby increasing the flow rate diverted to the inlet of the first flow channel.

17. The control method for a gas-fired hot water device according to claim 1, characterized in that, Step S20 specifically includes: Determine whether the outlet temperature of the domestic water is greater than the sum of the set domestic water temperature and the third preset temperature difference; the third preset temperature difference is greater than zero; If it is determined that the temperature of the domestic water outlet is greater than the sum of the domestic water set temperature and the third preset temperature difference, the flow regulating device is controlled to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first channel, so that the flow rate to the inlet of the first channel is reduced.

18. The control method for a gas-fired hot water device according to claim 17, characterized in that, After determining whether the outlet temperature of the domestic water is greater than the sum of the set domestic water temperature and the third preset temperature difference, the method further includes: If it is determined that the outlet temperature of the domestic water is not greater than the sum of the set domestic water temperature and the third preset temperature difference, then it is determined whether the outlet temperature of the domestic water is greater than the sum of the set domestic water temperature and the fourth preset temperature difference; the fourth preset temperature difference is greater than zero and less than the third preset temperature difference. If it is determined that the temperature of the domestic water outlet is greater than the sum of the domestic water set temperature and the fourth preset temperature difference, the flow regulating device is controlled to keep the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first channel constant, so that the flow rate to the inlet of the first channel remains constant.

19. The control method for a gas-fired hot water device according to claim 1, characterized in that, Step S20 specifically includes: Determine whether the outlet temperature of the domestic water is less than the difference between the set domestic water temperature and the fifth preset temperature difference; the fifth preset temperature difference is greater than zero. If it is determined that the temperature of the domestic water outlet is less than the difference between the domestic water set temperature and the fifth preset temperature difference, the flow regulating device is controlled to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first channel, so that the flow rate to the inlet of the first channel increases by a first magnitude.

20. The control method for a gas-fired hot water device according to claim 19, characterized in that, After determining whether the outlet temperature of the domestic water is less than the difference between the set domestic water temperature and the fifth preset temperature difference, the method further includes: If it is determined that the domestic water outlet temperature is not less than the difference between the domestic water set temperature and the fifth preset temperature difference, then it is determined whether the domestic water outlet temperature is less than the domestic water set temperature. If the temperature of the domestic water outlet is determined to be lower than the set temperature of the domestic water, the flow regulating device is controlled to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first channel, so that the flow rate to the inlet of the first channel increases by a second magnitude, the second magnitude being smaller than the first magnitude.

21. The control method for a gas-fired hot water device according to claim 20, characterized in that, After determining whether the outlet temperature of the domestic water is lower than the set temperature of the domestic water, the method further includes: If it is determined that the domestic water outlet temperature is not less than the domestic water set temperature, it is determined whether the domestic water outlet temperature is less than the sum of the domestic water set temperature and the sixth preset temperature difference; the sixth preset temperature difference is greater than zero. If it is determined that the temperature of the domestic water outlet is less than the sum of the domestic water set temperature and the sixth preset temperature difference, the flow regulating device is controlled to adjust the ratio between the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the flow rate diverted to the inlet of the first flow channel, so that the flow rate to the inlet of the first flow channel increases by a third magnitude, the third magnitude being less than the second magnitude.

22. The control method for a gas-fired hot water device according to any one of claims 6, 12, and 15, characterized in that, After controlling the burner to burn according to the target power to heat the first heat exchanger, the method further includes: When the heating outlet water temperature is greater than the sum of the domestic water set temperature and the first preset temperature difference, the burner is controlled to stop burning.

23. A controller, characterized in that, The controller includes a processor and a memory for storing processor-executable instructions, wherein the processor executes the instructions to implement the steps of the gas-fired water heater control method according to any one of claims 1 to 22.

24. A gas-fired hot water device, characterized in that, The gas-fired hot water device includes: The controller according to claim 23; First heat exchanger; A burner for heating the first heat exchanger; A first pipeline and a second pipeline, wherein the first pipeline is used to direct at least a portion of the water flowing out of the outlet of the first heat exchanger to the indoor heating equipment, and the second pipeline is used to return the water flowing through the indoor heating equipment to the inlet of the first heat exchanger. The second heat exchanger has a first flow channel and a second flow channel that are isolated from each other. The inlet of the first flow channel can be connected to the first pipeline so that at least part of the water in the first pipeline can flow into the inlet of the first flow channel. The outlet of the first flow channel can be connected to the second pipeline so that the water flowing out of the outlet of the first flow channel can flow into the second pipeline. The second flow channel is used for circulating domestic water. The water flowing through the first flow channel and the water flowing through the second flow channel can exchange heat. A flow regulating device is used to regulate the flow rate of water flowing into the first pipeline to the inlet of the indoor heating equipment and the inlet of the first flow channel; A circulation pump is installed on the first pipeline or the second pipeline. The circulation pump can be used to drive water flowing from the outlet of the indoor heating equipment into the second pipeline to flow through the first heat exchanger and then from the first pipeline to the inlet of the indoor heating equipment. The circulation pump is also used to drive water flowing from the outlet of the first channel into the second pipeline to flow through the first heat exchanger and then from the first pipeline to the inlet of the first channel.

25. The gas-fired hot water device according to claim 24, characterized in that, The flow regulating device includes a three-way valve; The first port of the three-way valve is connected to the first pipeline, the second port of the three-way valve is connected to the inlet of the first flow channel, and the third port of the three-way valve is connected to the inlet of the indoor heating equipment. or, The first port of the three-way valve is connected to the second pipeline, the second port of the three-way valve is connected to the outlet of the first flow channel, and the third port of the three-way valve is connected to the outlet of the indoor heating equipment.

26. The gas-fired hot water device according to claim 24, characterized in that, The gas-fired water heater further includes: a first connecting pipe, which connects the inlet of the first pipe and the inlet of the first flow channel; and a second connecting pipe, which connects the outlet of the second pipe and the first flow channel. The flow regulating device includes: A first valve is installed on the first connecting pipe or the second connecting pipe to regulate the flow rate of water flowing into or out of the first flow channel. The second valve is disposed on the first pipe between the first connecting portion between the first pipe and the first connecting pipe and the inlet of the indoor heating equipment, to regulate the water flow rate into the indoor heating equipment; or, the second valve is disposed on the second pipe between the second connecting portion between the second pipe and the second connecting pipe and the outlet of the indoor heating equipment, to regulate the water flow rate out of the indoor heating equipment.

27. The gas-fired hot water device according to claim 24, characterized in that, The gas-fired hot water device also includes: The first temperature sensor is used to detect the heating water outlet temperature, which is the water temperature flowing out of the outlet of the first heat exchanger. The second temperature sensor is used to detect the temperature of the domestic water outlet, which is the water temperature flowing out of the outlet of the second flow channel of the second heat exchanger.

28. A heating system, characterized in that, include: Gas-fired hot water device according to any one of claims 24 to 27; An indoor heating device, wherein the inlet of the indoor heating device is connected to the outlet of the first heat exchanger via a first pipe, and the outlet of the indoor heating device is connected to the inlet of the first heat exchanger via a second pipe.

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