Gas water heater and control method thereof

Abstract

This invention relates to a gas water heater and its control method. The gas water heater includes a heat exchanger, a cold water pipe, a hot water pipe, an inlet pipe, an outlet pipe, a solenoid valve installed in the cold water pipe, and an automatic thermostatic device. The automatic thermostatic device includes a tank, a baffle and a temperature sensor installed in the tank, and a drive mechanism. The control method of this invention includes: receiving a water usage start signal, which indicates that water usage has started; acquiring the water temperature in the second sub-space; calculating the temperature difference between the set temperature of the gas water heater and the water temperature; adjusting the opening of the solenoid valve according to the temperature difference, thereby adjusting the water flow rate in the cold water pipe; and controlling the start and stop of the drive mechanism according to the water flow rate in the cold water pipe. This invention not only improves the water mixing effect and reduces the noise caused by frequent starts of the ignition system, but also prioritizes outputting more water from the second sub-space when the water temperature in the second sub-space is higher, minimizing the user's waiting time for water.

Description

Technical Field

[0001] This invention relates to the field of water heater technology, and in particular to a gas water heater and its control method. Background Technology

[0002] Currently, gas water heaters on the market experience a process where, after the water valve is closed and reopened, the water goes through a cycle of high-temperature hot water, cold water, and then room-temperature hot water. This phenomenon is known as the "sandwich effect" or "intercalated water." In other words, after restarting, the water heater needs time to stabilize at the set bathing temperature, significantly impacting user comfort. The main reason for this problem is that after the water valve is closed, the residual heat from the heat exchanger continues to heat the water stored inside the unit, making its temperature higher than the set temperature. When the water valve is reopened, this high-temperature stored water flows out first, forming hot water. The water heater uses the water flow signal as its start-up signal, so it only ignites and begins working when water flow is generated after the valve is reopened. There is a time lag between the water heater receiving the flow signal and the water reaching the set temperature. During this time, the flowing water is not heated before flowing out of the valve, creating a certain amount of cold water.

[0003] The following methods are commonly used in existing technologies to solve the aforementioned technical problems. First, adding a mixing device; some gas water heaters currently have a mixing tank at the outlet pipe. When the user uses hot water, some hot water is stored in the mixing tank. When the water supply is briefly interrupted and then restarted, the water in the outlet pipe mixes with the hot water in the tank before flowing out together. Second, adding an electric heating module; by adding an electric heating module to the gas water heater, when the water valve is briefly closed and then restarted, the flowing cold water is heated by the electric heating module, thus eliminating the cold water in the interlayer. Third, using energy storage materials; during normal hot water use, the energy storage material absorbs heat. When the water valve is briefly closed and then restarted, the energy storage material releases the stored heat to heat the flowing cold water.

[0004] However, electric heating modules are costly to develop, have complex control programs, and are susceptible to scale buildup from water ions, leading to a significant decrease in heating efficiency over time. Energy storage materials are expensive, the technology is immature, and their performance does not yet meet usage requirements; they remain theoretical and have not been put into practical use. Therefore, the lowest-cost and simplest-to-control solution currently is the mixing tank solution. However, existing mixing tank solutions simply connect a large water tank to the end of the outlet pipe, resulting in an unreasonable structural design. This limits the outflow of hot water from the mixing tank, leading to poor mixing and an inability to effectively solve the cold water problem. Summary of the Invention

[0005] One objective of the first aspect of this invention is to overcome at least one deficiency of the prior art and to provide a control method that can improve the mixing effect of a gas water heater, reduce its operating noise, and extend its service life.

[0006] Another objective of the first aspect of this invention is to reduce the waiting time for users to use water.

[0007] The second objective of this invention is to provide a gas water heater that has good water mixing effect, low noise, and long service life.

[0008] According to a first aspect of the present invention, the present invention provides a control method for a gas water heater, the gas water heater comprising a heat exchanger, a cold water pipe connected to an upstream side of the heat exchanger, a hot water pipe connected to a downstream side of the heat exchanger, an inlet pipe for connecting to a tap water pipe, an outlet pipe for connecting to a water user, a solenoid valve disposed within the cold water pipe to adjust the flow area of ​​the cold water pipe, and an automatic thermostatic device, the automatic thermostatic device comprising a tank, a baffle and a temperature sensor disposed within the tank, and a drive mechanism;

[0009] The baffle divides the space inside the tank into a fluid-isolated first subspace and a second subspace; the drive mechanism is connected to the baffle and configured to controllably move the baffle along the arrangement direction of the first and second subspaces to adjust the volume of the first and second subspaces; the temperature sensor is used to acquire the water temperature in the second subspace; wherein

[0010] The inlet pipe is connected to the first subspace, the hot water pipe and the outlet pipe are both connected to the second subspace, and the cold water pipe is configured to switch from being connected to the second subspace to being connected to the first subspace when water is used at the water-using end, and to switch from being connected to the first subspace to being connected to the second subspace when water is used at the water-using end; and

[0011] The control method includes:

[0012] Receive a water usage start signal, the water usage start signal being used to indicate that the water user has started water usage;

[0013] Obtain the water temperature in the second subspace;

[0014] Calculate the temperature difference between the set temperature of the gas water heater and the water temperature;

[0015] The opening degree of the solenoid valve is adjusted according to the temperature difference, thereby regulating the water flow rate in the cold water pipe;

[0016] The start and stop of the drive mechanism are controlled according to the water flow rate in the cold water pipe.

[0017] Optionally, the step of adjusting the opening degree of the solenoid valve according to the temperature difference, thereby adjusting the water flow rate in the cold water pipe, includes:

[0018] If the temperature difference is greater than the preset temperature difference value, the opening degree of the solenoid valve is adjusted to the preset maximum opening degree;

[0019] If the temperature difference is less than or equal to the preset temperature difference, the opening of the solenoid valve is adjusted to the preset minimum opening; wherein

[0020] The preset minimum opening is set so that the water flow in the cold water pipe is just enough to trigger the ignition system of the gas water heater to start.

[0021] Optionally, the drive mechanism includes a motor located outside the tank, a helical rod connected to the motor and extending into the tank, and a telescopic rod selectively retracting into or extending from the helical rod, the end of the telescopic rod being connected to the baffle; and

[0022] The steps for controlling the start and stop of the drive mechanism based on the water flow rate in the cold water pipe include:

[0023] Receive an ignition start signal, which is generated when the water flow rate in the cold water pipe reaches the preset ignition flow rate;

[0024] Start the ignition system and control the motor to rotate in the forward direction.

[0025] Optionally, if the opening degree of the solenoid valve is the preset minimum opening degree, after starting the ignition system and controlling the motor to rotate in the forward direction, the control method of the present invention further includes:

[0026] Obtain the water flow rate in the outlet pipe;

[0027] Adjust the opening of the solenoid valve according to the water flow rate in the outlet pipe until the opening of the solenoid valve reaches the preset maximum opening; and

[0028] The speed of the motor is adjusted according to the water flow rate in the outlet pipe and the opening degree of the solenoid valve, so as to adjust the speed of the baffle movement until the baffle moves to the preset position.

[0029] Optionally, the step of adjusting the opening degree of the solenoid valve according to the water flow rate of the outlet pipe includes:

[0030] The opening degree of the solenoid valve is calculated using the following formula:

[0031] y t = k×t + y0; where

[0032] y t The value represents the opening degree of the solenoid valve at time t after receiving the ignition start signal, where t represents the water usage time since receiving the ignition start signal, y0 represents the preset minimum opening degree, and k represents a coefficient proportional to the user's water flow rate.

[0033] Optionally, the step of adjusting the motor speed according to the water flow rate in the outlet pipe and the opening degree of the solenoid valve to adjust the speed of the baffle movement includes:

[0034] The water flow rate in the cold water pipe is calculated based on the opening degree of the solenoid valve;

[0035] Calculate the flow rate difference between the water flow rate in the outlet pipe and the water flow rate in the cold water pipe;

[0036] The target moving speed of the baffle is calculated using the following formula:

[0037] Q0 = (Q1 - Q2) / S; where Q0 represents the flow difference, Q1 represents the water flow rate in the outlet pipe, Q2 represents the water flow rate in the cold water pipe, and S represents the cross-sectional area of ​​the tank.

[0038] Calculate the target rotational speed of the motor based on the target moving speed of the baffle; and

[0039] Control the motor to run at the target speed.

[0040] Optionally, if the opening degree of the solenoid valve is the preset maximum opening degree, after starting the ignition system and controlling the motor to rotate in the forward direction, the control method further includes:

[0041] Control the motor to rotate forward at a preset minimum speed until the baffle moves to a preset position.

[0042] Optionally, after the baffle moves to the preset position, the control method further includes:

[0043] Receive a water usage stop signal, the water usage stop signal being used to indicate that the water-using end has stopped using water; and

[0044] The opening degree of the solenoid valve is adjusted to a preset initial opening degree, and the motor is controlled to rotate in the reverse direction; wherein

[0045] The preset initial opening degree is greater than zero and less than the preset minimum opening degree.

[0046] Optionally, after receiving the water use stop signal, the control method further includes:

[0047] Receive an ignition stop signal, which is generated when the water flow rate in the cold water pipe is less than the preset ignition flow rate; and

[0048] Stop the ignition system.

[0049] Optionally, the preset ignition flow rate is set to be greater than the maximum water flow rate in the cold water pipe when the cold water pipe is connected to the second subspace, and equal to or less than the minimum water flow rate in the cold water pipe when the cold water pipe is connected to the first subspace.

[0050] According to a second aspect of the present invention, the present invention also provides a gas water heater, comprising a heat exchanger, a cold water pipe connected to the upstream side of the heat exchanger, a hot water pipe connected to the downstream side of the heat exchanger, an inlet pipe for connecting to a tap water pipe, an outlet pipe for connecting to a water user, a solenoid valve disposed in the cold water pipe to adjust the flow area of ​​the cold water pipe, and an automatic thermostatic device, the automatic thermostatic device comprising a tank, a baffle and a temperature sensor disposed in the tank, and a drive mechanism;

[0051] The baffle divides the space inside the tank into a fluid-isolated first subspace and a second subspace; the drive mechanism is connected to the baffle and is configured to controllably drive the baffle to move along the arrangement direction of the first subspace and the second subspace to adjust the volume of the first subspace and the second subspace; the temperature sensor is used to obtain the water temperature in the second subspace;

[0052] The inlet pipe is connected to the first subspace, the hot water pipe and the outlet pipe are both connected to the second subspace, and the cold water pipe is configured to switch from being connected to the second subspace to being connected to the first subspace when water is used at the water-using end, and to switch from being connected to the first subspace to being connected to the second subspace when water is used at the water-using end; and

[0053] The gas water heater also includes a control device electrically connected to the solenoid valve and the drive mechanism. The control device includes a processor and a memory. The memory stores a machine-executable program, and when the machine-executable program is executed by the processor, it is used to implement the control method described in any of the above schemes.

[0054] This invention relates to a gas water heater that divides the traditional cold water inlet pipe and hot water outlet pipe into two sections, forming four parts: a cold water pipe, a hot water pipe, an inlet pipe, and an outlet pipe. Furthermore, it incorporates an automatic thermostatic device with a solenoid valve, a tank, a baffle, a drive mechanism, and a temperature sensor. The baffle divides the space inside the tank into a fluid-isolated first subspace and a second subspace. The inlet pipe connects to the first subspace, while the hot water pipe and outlet pipe connect to the second subspace. The cold water pipe selectively connects to either the first or second subspace. Thus, the hot water flowing from the hot water pipe first flows into the second subspace to mix with the water stored there before flowing to the outlet pipe. Compared to existing technologies where mixing occurs only within the hot water outlet pipe, this invention provides a larger mixing space, resulting in faster mixing and a better mixing effect.

[0055] Furthermore, upon receiving a water usage start signal, the system first acquires the water temperature in the second sub-space. Based on the temperature difference between the gas water heater's set temperature and the water temperature in the second sub-space, it adjusts the opening of the solenoid valve. This control of the solenoid valve opening controls the water flow rate in the cold water pipe (i.e., the flow rate to the heat exchanger and from the hot water pipe to the second sub-space). Given a fixed user water flow rate, this indirectly controls the proportion of water stored in the second sub-space in the water flowing out of the outlet pipe. In this way, when the water temperature in the second sub-space is close to the set temperature, more water stored in the second sub-space is preferentially output; when the water temperature in the second sub-space differs significantly from the set temperature, more hot water, after heat exchange in the heat exchanger, is added to the second sub-space to mix with the stored water before flowing out through the outlet pipe. It is understandable that if the water consumption at the user's end is small, the water stored in the second sub-space is sufficient to meet the user's needs, and in this case, there is no need to start the ignition system. This invention, while meeting users' water temperature requirements, minimizes the need for frequent ignition system starts, reduces noise caused by frequent ignition system starts, avoids component fatigue failure, thereby extending service life and reducing the probability of safety accidents.

[0056] Furthermore, if the water consumption at the water-using end is large, the water temperature output by the ignition system will need to stabilize to the set temperature after a period of time after startup. Before that, if more water stored in the second subspace with a temperature close to the set temperature is output first, the user's waiting time for water can be reduced, thus improving the user experience.

[0057] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0058] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0059] Figure 1 This is a schematic structural diagram of a gas water heater in a stopped water supply state according to an embodiment of the present invention;

[0060] Figure 2 This is a schematic structural diagram of a gas water heater in a state switching process according to an embodiment of the present invention;

[0061] Figure 3 This is a schematic structural diagram of a gas water heater in a continuous water output state according to an embodiment of the present invention;

[0062] Figure 4 This is a schematic flowchart of a control method for a gas water heater according to an embodiment of the present invention;

[0063] Figure 5 This is a schematic flowchart of a control method for a gas water heater according to another embodiment of the present invention;

[0064] Figure 6 This is a schematic structural diagram of a drive mechanism according to an embodiment of the present invention;

[0065] Figure 7 This is a schematic flowchart of a control method for a gas water heater according to yet another embodiment of the present invention;

[0066] Figure 8 This is a schematic flowchart illustrating the adjustment of motor speed according to the water flow rate in the outlet pipe 24 and the opening degree of the solenoid valve 50 according to an embodiment of the present invention.

[0067] Figure 9 This is a schematic flowchart of a control method for a gas water heater according to another embodiment of the present invention;

[0068] Figure 10 This is a schematic structural block diagram of a gas water heater according to an embodiment of the present invention. Detailed Implementation

[0069] This invention first provides a control method for a gas water heater, which is applicable to gas water heaters with special structures. Figure 1 This is a schematic structural diagram of a gas water heater in a stopped water supply state according to an embodiment of the present invention. Figure 2 This is a schematic structural diagram of a gas water heater in a state switching process according to an embodiment of the present invention. Figure 3This is a schematic structural diagram of a gas water heater in a continuous water supply state according to an embodiment of the present invention. (See also...) Figures 1 to 3 The gas water heater 1 of the present invention includes a heat exchanger 10, a cold water pipe 21 connected to the upstream side of the heat exchanger 10, a hot water pipe 22 connected to the downstream side of the heat exchanger 10, an inlet pipe 23 for connecting to a tap water pipe, an outlet pipe 24 for connecting to a water outlet, and an automatic thermostatic device 30. It is understood that the water outlet can specifically be a faucet, a shower head, etc.

[0070] Specifically, the gas water heater 1 of the present invention further includes a solenoid valve 50 disposed within the cold water pipe 21 to adjust the flow area of ​​the cold water pipe 21, and an automatic thermostatic device 30. The automatic thermostatic device 30 includes a tank 31, a baffle 32 disposed within the tank 31, a temperature sensor (not shown in the figure), and a drive mechanism 33. The baffle 32 divides the space within the tank 31 into a fluid-isolated first subspace 311 and a second subspace 312. That is, the first subspace 311 and the second subspace 312 are fluidly isolated by the baffle 32, and there is no fluid communication between them. The drive mechanism 33 is connected to the baffle 32, and the drive mechanism 33 is configured to controllably drive the baffle 32 to move along the arrangement direction of the first subspace 311 and the second subspace 312 to adjust the volume of the first subspace 311 and the second subspace 312. Specifically, the baffle 32 can move along the first direction a and the second direction b in the figure under the action of the drive mechanism 33. The temperature sensor is used to obtain the water temperature in the second subspace 312. The inlet pipe 23 is connected to the first subspace 311, and both the hot water pipe 22 and the outlet pipe 24 are connected to the second subspace 312. The cold water pipe 21 is configured to switch from being connected to the second subspace 312 to being connected to the first subspace 311 when water use is started at the water-using end, and to switch from being connected to the first subspace 311 to being connected to the second subspace 312 when water use is stopped at the water-using end. That is to say, when water use is started at the water-using end, the cold water pipe 21 is in the state of being connected to the second subspace 312. As the water use time increases, the distance that the baffle 32 moves along the first direction a gradually increases, the volume of the second subspace 312 becomes smaller and smaller, and the volume of the first subspace 311 becomes larger and larger, so the cold water pipe 21 can switch to the state of being connected to the first subspace 311. When water usage is stopped at the water-using end, the cold water pipe 21 is in a state of being connected to the first subspace 311. As the time of water usage cessation increases, the distance that the baffle 32 moves along the second direction b becomes larger and larger, the volume of the second subspace 312 becomes larger and larger, and the volume of the first subspace 311 becomes smaller and smaller. The cold water pipe 21 can then switch to a state of being connected to the second subspace 312.

[0071] Specifically, the tank 31 may have four connection ports that are respectively connected to the cold water pipe 21, the hot water pipe 22, the inlet pipe 23 and the outlet pipe 24, so as to allow the cold water pipe 21, the hot water pipe 22, the inlet pipe 23 and the outlet pipe 24 to connect to the first subspace 311 or the second subspace 312 inside the tank 31 through the corresponding connection ports.

[0072] The gas water heater 1 of the present invention divides the conventional cold water inlet pipe and hot water outlet pipe into two sections, forming four parts: cold water pipe 21, hot water pipe 22, inlet pipe 23, and outlet pipe 24. Furthermore, it is specially equipped with an automatic thermostatic device 30 comprising a tank 31, a baffle 32, a drive mechanism 33, and a temperature sensor. The baffle 32 divides the space within the tank 31 into a fluid-isolated first subspace 311 and a second subspace 312. The inlet pipe 23 is connected to the first subspace 311, while the hot water pipe 22 and the outlet pipe 24 are both connected to the second subspace 312. The cold water pipe 21 is selectively connected to either the first subspace 311 or the second subspace 312. Therefore, the hot water flowing out of the hot water pipe 22 first flows to the second subspace 312 to mix with the water stored in the second subspace 312 before flowing to the outlet pipe 24. Compared with the prior art, which mixes in the hot water outlet pipe, the present invention has a specially set mixing space (second subspace 312), which is larger. Therefore, the mixing speed is faster and the water mixing effect is better.

[0073] The control method of the present invention is designed based on a gas water heater 1 having at least the above-described structure. Figure 4 This is a schematic flowchart of a control method for a gas water heater according to an embodiment of the present invention. The control method of the present invention includes:

[0074] Step S10: Receive a water usage start signal, which indicates that the water user has started using water.

[0075] Step S20: Obtain the water temperature in the second subspace 312;

[0076] Step S30: Calculate the temperature difference between the set temperature of the gas water heater 1 and the water temperature in the second subspace 312;

[0077] Step S40: Adjust the opening degree of the solenoid valve 50 according to the temperature difference, thereby adjusting the water flow rate in the cold water pipe 21; and

[0078] Step S50: Control the start and stop of the drive mechanism 33 according to the water flow rate in the cold water pipe 21.

[0079] When the gas water heater 1 of the present invention receives a water usage start signal, it first obtains the water temperature in the second sub-space 312. Based on the temperature difference between the set temperature of the gas water heater 1 and the water temperature in the second sub-space 312, it adjusts the opening of the solenoid valve 50. By controlling the opening of the solenoid valve 50, it controls the water flow rate in the cold water pipe 21 (i.e., controls the water flow to the heat exchanger 10 and from the hot water pipe 23 to the second sub-space 312), thereby controlling the start and stop of the drive mechanism 33. When the user's water usage is constant, it indirectly controls the proportion of water stored in the second sub-space 312 in the water flowing out of the outlet pipe 24. In this way, when the water temperature in the second sub-space 312 is close to the set temperature, more water stored in the second sub-space 312 is preferentially output; when the water temperature in the second sub-space 312 differs significantly from the set temperature, more hot water that has undergone heat exchange in the heat exchanger 10 is added to the second sub-space 312 to mix with the stored water before flowing out through the outlet pipe 24. Understandably, if the water consumption at the water-using end is small, the water stored in the second subspace 312 is sufficient to meet the user's needs, and there is no need to start the ignition system at all. This invention, while meeting the user's water temperature requirements, minimizes the need for frequent ignition system starts, reduces noise caused by frequent starts, avoids component fatigue failure, thereby extending service life and reducing the probability of safety accidents.

[0080] Furthermore, if the water consumption at the water-using end is large, the water temperature output by the ignition system will need to stabilize to the set temperature after a period of time after startup. Before that, if more water stored in the second subspace with a temperature close to the set temperature is output first, the user's waiting time for water can be reduced, thus improving the user experience.

[0081] It should be noted that the ignition system of the present invention has a broad meaning that includes a gas valve, and is used to control the ignition and extinguishing of a gas water heater. The start of the ignition system means controlling the gas water heater to ignite, and the stop of the ignition system means controlling the gas water heater to extinguish.

[0082] In some embodiments, step S40, which adjusts the opening of the solenoid valve 50 according to the temperature difference to regulate the water flow rate in the cold water pipe 21, may specifically include:

[0083] If the temperature difference is greater than the preset temperature difference value, the opening degree of the solenoid valve 50 will be adjusted to the preset maximum opening degree.

[0084] If the temperature difference is less than or equal to the preset temperature difference, the opening of the solenoid valve 50 is adjusted to the preset minimum opening. The preset minimum opening is set so that the water flow in the cold water pipe 21 is exactly the preset ignition flow that triggers the ignition system of the gas water heater 1.

[0085] Specifically, if the temperature difference is greater than the preset temperature difference value, it indicates that the water temperature in the second subspace 312 differs significantly from the set temperature of the gas water heater 1, and the water stored in the second subspace 312 alone is insufficient to meet the user's water temperature requirements. Therefore, in this case, the invention adjusts the opening of the solenoid valve 50 to the preset maximum opening, so that more water flows into the cold water pipe 21 after water is started at the water-using end, thereby allowing more water to flow into the second subspace 312 after heat exchange through the heat exchanger 10, thereby increasing the mixed water temperature in the second subspace 312 and quickly meeting the user's water temperature requirements.

[0086] Preferably, the preset maximum opening can be 100%.

[0087] If the temperature difference is less than or equal to the preset temperature difference value, it indicates that the water temperature in the second subspace 312 is close to the set temperature of the gas water heater 1, and the water stored in the second subspace 312 can basically meet the user's water temperature requirements. Therefore, at this time, the present invention adjusts the opening of the solenoid valve 50 to the preset minimum opening. On the one hand, when the water consumption at the water end is large, it can ensure that the water flow in the cold water pipe 21 can reach the preset ignition flow to start the ignition system, thereby ensuring that the ignition system can start normally to meet the user's large water demand. On the other hand, it also minimizes the water flow in the cold water pipe 21 as much as possible when the water consumption at the water end just begins to flow, causing more of the water stored in the second subspace 312 to flow to the outlet pipe 24, that is, to prioritize the output of the water stored in the second subspace 312. In this way, when the water consumption at the water end is small, the water stored in the second subspace 312 can meet the user's needs. At this time, there is no need to start the ignition system, avoiding frequent starting of the ignition system, reducing the noise caused by frequent starting of the ignition system, avoiding fatigue failure of components, thereby extending the service life and reducing the probability of safety accidents.

[0088] Specifically, Figure 5 This is a schematic flowchart of a control method for a gas water heater according to another embodiment of the present invention. The control method of the present invention includes:

[0089] Step S10: Receive a water usage start signal, which indicates that the water user has started using water.

[0090] Step S20: Obtain the water temperature in the second subspace 312;

[0091] Step S30: Calculate the temperature difference between the set temperature of the gas water heater 1 and the water temperature in the second subspace 312;

[0092] Step S41: Determine whether the temperature difference is greater than the preset temperature difference value; if yes, proceed to step S42; if no, proceed to step S43.

[0093] Step S42: Adjust the opening of the solenoid valve 50 to the preset maximum opening.

[0094] Step S43: Adjust the opening of the solenoid valve 50 to the preset minimum opening; and

[0095] Step S50: Control the start and stop of the drive mechanism 33 according to the water flow rate in the cold water pipe 21.

[0096] Figure 6 This is a schematic structural diagram of a drive mechanism according to an embodiment of the present invention. In some embodiments, the drive mechanism 33 includes a motor 331 located outside the tank body 31, a helical rod 332 connected to the motor 331 and extending into the tank body 31, and a telescopic rod 333 that selectively retracts into or extends from the helical rod 332, the end of which is connected to a baffle 32. Specifically, one end of the telescopic rod 333 can be sleeved with the helical rod 332 by a spring 334, so that it selectively retracts into or extends from the helical rod 332 as the spring 334 extends or retracts.

[0097] In these embodiments, see Figure 7 The schematic flowchart shown here is a control method for a gas water heater according to another embodiment of the present invention. The steps of controlling the start and stop of the drive mechanism 33 based on the water flow in the cold water pipe 21 may specifically include:

[0098] Step S51: Receive ignition start signal, which is generated when the water flow rate in the cold water pipe 21 reaches the preset ignition flow rate;

[0099] Step S52: Start the ignition system and control the motor 331 to rotate in the forward direction.

[0100] In other words, motor 331 only starts to rotate in the forward direction when the ignition system is started.

[0101] Specifically, when the water supply is continuously stopped at the water-using end, the inlet pressure at the inlet pipe 23 is the same as the outlet pressure at the outlet pipe 24. The forces on both sides of the baffle 32 are balanced and maintained at the first position A. The motor 31 is in a stopped state. Therefore, the spring connecting the telescopic rod 333 and the screw rod 332 is in a natural state, and the telescopic rod 333 is retracted into the screw rod 332. At this time, the larger second subspace 312 stores the hot water that flowed from the heat exchanger 10 after the last water use at the water-using end.

[0102] After the user starts using water, and before the ignition system starts, the pressure at the outlet pipe 24 drops sharply. The inlet pressure at the inlet pipe 23 is greater than the outlet pressure at the outlet pipe 24. Water flows into the first subspace 311 through the inlet pipe 23, squeezing the baffle 32. This causes the baffle 32 to move together with the telescopic rod 333 from the first position A towards the first direction a, pushing the hot water in the second subspace 312 towards the outlet pipe 24 so that the user can obtain hot water in time. During this process, the spring 33 undergoes elastic deformation. Since the cold water pipe 21 is connected to the second subspace 312 at this time, the water volume in the second subspace 312 is limited, and most of the water flows to the outlet pipe 24. Therefore, the water flow to the cold water pipe 21 is very small. At this time, the ignition system will not start, and the motor 331 will not rotate.

[0103] As the baffle 32 moves further in the first direction a, the cold water pipe 21 switches to be connected to the first subspace 311. At this time, the flow rate in the cold water pipe 21 reaches the preset ignition flow rate, the ignition system starts, the motor 331 rotates forward, driving the screw rod 332 to move in the first direction a. The screw rod 332 pushes the baffle 32 to continue moving in the first direction a until the baffle 32 moves to the third position C (i.e., the aforementioned preset position). At this point, the motor 331 stops rotating forward, the baffle 31 stops moving and remains at the third position C. After the cold water pipe 21 switches to be connected to the first subspace 311, most of the water flowing in through the inlet pipe 23 flows into the cold water pipe 21, with a small portion remaining in the first subspace 311. When the baffle 31 stops moving, the flow rate of water flowing in through the inlet pipe 23 is the same as the flow rate of water flowing into the cold water pipe 21 through the first subspace 311. When the cold water pipe 21 is connected to the first subspace 311, the water flow rate in the cold water pipe 21 increases, reaching the standard for starting the ignition system. The ignition system starts ignition, and the heat exchanger continuously generates hot water, which flows into the second subspace 312 through the hot water pipe 22, and then flows from the second subspace 312 to the outlet pipe 24.

[0104] In some embodiments, if the opening degree of the solenoid valve 50 is a preset minimum opening degree, after the ignition system is started and the motor 331 is controlled to rotate in the forward direction, the control method of the present invention further includes:

[0105] Step S61: Obtain the water flow rate in the outlet pipe 24;

[0106] Step S62: Adjust the opening of the solenoid valve 50 according to the water flow rate in the outlet pipe 24 until the opening of the solenoid valve 50 reaches the preset maximum opening; and

[0107] In step S63, the speed of motor 331 is adjusted according to the water flow rate in water outlet pipe 24 and the opening degree of solenoid valve 50, so as to adjust the moving speed of baffle 32 until baffle 32 moves to the preset position.

[0108] In other words, after the ignition system is started, the opening degree of the solenoid valve is not constant, but a variable related to the water flow rate in the outlet pipe 24. After the motor 331 starts to rotate in the forward direction, the speed of the motor 331 is also not constant, but a variable related to both the water flow rate in the outlet pipe 24 and the opening degree of the solenoid valve 50.

[0109] Specifically, the water flow rate in the outlet pipe 24 can be measured by the flow sensor 42 installed in the outlet pipe 24.

[0110] In some embodiments, the step of adjusting the opening degree of the solenoid valve 50 according to the water flow rate of the outlet pipe 24 may specifically include:

[0111] The opening degree of solenoid valve 50 is calculated using the following formula:

[0112] y t = k×t + y0; where

[0113] y t This indicates the opening degree of solenoid valve 50 at time t after receiving the ignition start signal, where t represents the water usage time since receiving the ignition start signal, y0 represents the preset minimum opening degree, and k represents a coefficient proportional to the user's water flow rate. In other words, multiple different k values ​​can be preset; the greater the user's water flow rate (e.g., the larger the faucet opening), the larger the value of k.

[0114] Based on the above-mentioned determination of the opening degree of the solenoid valve 50, the present invention can gradually increase the opening degree of the solenoid valve 50 from the preset minimum opening degree after receiving the ignition start signal, so as to ensure that enough water is heated by the heat exchanger 10 and replenished into the second subspace 312 to meet the user's water consumption needs.

[0115] Figure 8 This is a schematic flowchart illustrating the adjustment of motor speed based on the water flow rate in the outlet pipe 24 and the opening degree of the solenoid valve 50 according to an embodiment of the present invention. In some embodiments, step S55, which adjusts the motor speed based on the water flow rate in the outlet pipe 24 and the opening degree of the solenoid valve 50 to adjust the moving speed of the baffle 32, may specifically include:

[0116] Step S631: Calculate the water flow rate in the cold water pipe 21 based on the opening degree of the solenoid valve 50;

[0117] Step S632: Calculate the flow rate difference between the water flow rate in water pipe 24 and the water flow rate in cold water pipe 21;

[0118] Step S633: Calculate the target moving speed of the baffle 32 according to the following formula:

[0119] Q0 = (Q1 - Q2) / S; where Q0 represents the flow difference, Q1 represents the water flow rate in the outlet pipe 24, Q2 represents the water flow rate in the cold water pipe 21, and S represents the cross-sectional area of ​​the tank 31.

[0120] Step S634: Calculate the target rotational speed of motor 331 based on the target moving speed of baffle 32; and

[0121] Step S635: Control motor 331 to run at the target speed.

[0122] The present invention controls the speed of motor 331 according to the water flow rate in outlet pipe 24 and the water flow rate in cold water pipe 21, which not only meets the different water consumption needs of users, but also controls the water flow rate in cold water pipe 21 in a targeted manner, thereby controlling the ratio between the water consumption in the second subspace 312 and the hot water consumption after heat exchange by heat exchanger 10.

[0123] In some embodiments, see Figure 7 If the opening degree of the solenoid valve 50 is the preset maximum opening degree, then after starting the ignition system and controlling the motor 331 to rotate in the forward direction, the control method of the present invention further includes:

[0124] Step S61': Control motor 331 to rotate forward at a preset minimum speed until baffle 32 moves to a preset position.

[0125] In other words, when the water temperature in the second subspace 312 differs significantly from the set temperature of the gas water heater 1, after the ignition system is started, the motor 331 rotates at a preset minimum speed until the baffle 32 moves to a preset position (e.g., the third position C) and stops rotating in the forward direction. This ensures that more water flows into the second subspace 312 after heat exchange through the heat exchanger 10, and then mixes with the water stored in the second subspace 312 before flowing to the outlet pipe 24 to meet the user's water temperature requirements.

[0126] Figure 9 This is a schematic flowchart of a control method for a gas water heater according to another embodiment of the present invention. In some embodiments, after the opening degree of the solenoid valve 50 is set to a preset maximum opening degree, the control method of the present invention further includes:

[0127] Step S71: Receive a water usage stop signal, which indicates that the water user has stopped using the water.

[0128] Step S72: Adjust the opening of the solenoid valve 50 to the preset initial opening, and control the motor 331 to rotate in the reverse direction; wherein

[0129] The initial opening is set to be greater than zero and less than the minimum opening.

[0130] In other words, when the water supply stops, fluid is allowed to continue flowing through the cold water pipe 21, but the maximum allowable flow rate is less than the preset ignition flow rate. This is because when a water supply stop signal is received, the motor 331 starts to rotate in the reverse direction, driving the screw rod 332 to move the baffle 32 in the second direction b. The baffle 32 pushes the water in the first subspace 311 from the cold water pipe 21 into the heat exchanger 10, and after flowing through the heat exchanger 10, it enters the second subspace 312. During this process, by controlling the opening of the solenoid valve 50, the water flow rate in the cold water pipe 21 can be prevented from reaching the preset ignition flow rate, thus preventing the ignition system from restarting.

[0131] Furthermore, the motor 331 automatically stops rotating in the reverse direction after rotating a preset angle. This preset angle is the angle that the motor 331 rotates from starting to rotating in the forward direction until it stops rotating in the forward direction. That is, the motor 331 stops rotating in the reverse direction when it returns to its original state.

[0132] Furthermore, after receiving the water usage stop signal, the control method of the present invention further includes:

[0133] Receives an ignition stop signal; the ignition stop signal is generated when the water flow rate in the cold water pipe 21 is less than the preset ignition flow rate; and

[0134] Stop the ignition system.

[0135] As mentioned earlier, when water usage stops at the water-using end, the opening degree of the solenoid valve 50 is greater than zero and less than the preset minimum opening degree. At this time, the water flow rate in the cold water pipe 21 will inevitably be less than the preset ignition flow rate. Therefore, the ignition system stops when water usage stops at the water-using end to control flameout. Specifically, the water flow rate in the cold water pipe 21 can be obtained by the flow sensor 41 installed in the cold water pipe 21.

[0136] When the motor 331 stops reversing, the spring 334 begins to recover its deformation. Under the action of the elastic deformation recovery force of the spring 334, the baffle 32 continues to move in the second direction b. A small amount of water in the second subspace 312 flows to the heat exchanger 10 through the cold water pipe 21, absorbs a small amount of residual heat from the heat exchanger 10, and then flows into the second subspace 312 through the hot water pipe 22 until the spring 334 has completely recovered its deformation. Then the baffle 32 stops moving and returns to the first position A. At this time, the second subspace 312 stores a large amount of warm water at a suitable temperature for the user to use next time.

[0137] In some embodiments, the preset ignition flow rate is set to be greater than the maximum water flow rate in the cold water pipe 21 when it is connected to the second subspace 312, and equal to or less than the minimum water flow rate in the cold water pipe 21 when it is connected to the first subspace 311. That is, when the cold water pipe 21 is connected to the second subspace 312, the ignition system will not start; when the cold water pipe 21 is switched to a state where it is just fully connected to the first subspace 311 (e.g., ...), the ignition system will not start. Figure 2 When water flows into the inlet pipe 23 (position B in the second subspace), the ignition system will start immediately. This ensures that when the water consumption at the water end is low, the pre-stored warm water in the second subspace 312 is used to meet the user's water needs without having to start the ignition system, thus avoiding frequent starts of the ignition system; and it also ensures that the ignition system can start stably when the water consumption at the water end is high, so as to meet the user's higher water consumption needs.

[0138] The present invention also provides a gas water heater, see below. Figures 1 to 3 The gas water heater 1 of the present invention includes a heat exchanger 10, a cold water pipe 21 connected to the upstream side of the heat exchanger 10, a hot water pipe 22 connected to the downstream side of the heat exchanger 10, an inlet pipe 23 for connecting to a tap water pipe, an outlet pipe 24 for connecting to a water user, and an automatic thermostat 30. The automatic thermostat 30 includes a tank 31, a baffle 32 and a temperature sensor disposed within the tank 31, and a drive mechanism 33.

[0139] A baffle 32 divides the space within the tank 31 into a fluid-isolated first subspace 311 and a second subspace 312. A drive mechanism 33 is connected to the baffle 32 and is configured to controllably move the baffle 32 along the arrangement direction of the first subspace 311 and the second subspace 312 to adjust the volume of the first subspace 311 and the second subspace 312. A temperature sensor is used to obtain the water temperature in the second subspace 312. The inlet pipe 23 is connected to the first subspace 311, and both the hot water pipe 22 and the outlet pipe 24 are connected to the second subspace 312. The cold water pipe 21 is configured to switch from being connected to the second subspace 312 to being connected to the first subspace 311 when water is started at the water-using end, and to switch from being connected to the first subspace 311 to being connected to the second subspace 312 when water is stopped at the water-using end.

[0140] In particular, Figure 10 This is a schematic structural block diagram of a gas water heater according to an embodiment of the present invention. The gas water heater 1 also includes a solenoid valve 50 disposed in the cold water pipe 21 to adjust the flow area of ​​the cold water pipe 21, and a control device 60 electrically connected to the solenoid valve 50 and the drive mechanism 33. The control device 60 includes a processor 61 and a memory 62. The memory 62 stores a machine-executable program 63, and when the machine-executable program 63 is executed by the processor 61, it is used to implement the control method described in any of the above embodiments.

[0141] Furthermore, the automatic thermostat 30 also includes an insulation layer (not shown in the figure), which covers the outside of the tank 31 to prevent heat loss from the water stored in the second subspace 312, so that hot water can still be obtained in time when the water is turned on again after a long period of inactivity.

[0142] Those skilled in the art should understand that the embodiments described above are merely some embodiments of the present invention, and not all embodiments of the present invention. These embodiments are intended to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Based on the embodiments provided by the present invention, all other embodiments obtained by those skilled in the art without creative effort should still fall within the scope of protection of the present invention.

[0143] It should be noted that in the description of this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0144] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can also refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0145] Furthermore, it should be noted that in the description of this invention, each functional module can be a physical module composed of multiple structures, components, or electronic devices, or a virtual module composed of multiple programs; each functional module can be an independent module or a module divided from a whole module according to its function. Those skilled in the art should understand that, provided the technical solution described in this invention can be implemented, any changes in the configuration, implementation, or positional relationship of the functional modules will not deviate from the technical principles of this invention, and therefore should all fall within the protection scope of this invention.

[0146] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A control method for a gas water heater, the gas water heater comprising a heat exchanger, a cold water pipe connected to the upstream side of the heat exchanger, a hot water pipe connected to the downstream side of the heat exchanger, an inlet pipe for connecting to a tap water pipe, an outlet pipe for connecting to a water user, a solenoid valve disposed within the cold water pipe to adjust the flow area of ​​the cold water pipe, and an automatic thermostatic device, the automatic thermostatic device comprising a tank, a baffle and a temperature sensor disposed within the tank, and a drive mechanism; The baffle divides the space inside the tank into a fluid-isolated first subspace and a second subspace; the drive mechanism is connected to the baffle and is configured to controllably drive the baffle to move along the arrangement direction of the first subspace and the second subspace to adjust the volume of the first subspace and the second subspace; the temperature sensor is used to obtain the water temperature in the second subspace; in The inlet pipe is connected to the first subspace, and the hot water pipe and the outlet pipe are both connected to the second subspace. The cold water pipe is configured to switch from being connected to the second subspace to being connected to the first subspace when water is started at the water-using end, and to switch from being connected to the first subspace to being connected to the second subspace when water is stopped at the water-using end. When water is started at the water-using end, the cold water pipe is connected to the second subspace. As the water usage time increases, the distance the baffle moves along the first direction a gradually increases, the volume of the second subspace becomes smaller and smaller, the volume of the first subspace becomes larger and larger, and the cold water pipe switches to being connected to the first subspace. When water is stopped at the water-using end, the cold water pipe is connected to the first subspace. As the water usage time decreases, the distance the baffle moves along the second direction b increases, the volume of the second subspace becomes larger and larger, the volume of the first subspace becomes smaller and smaller, and the cold water pipe switches to being connected to the second subspace. and The control method includes: Receive a water usage start signal, the water usage start signal being used to indicate that the water user has started water usage; Obtain the water temperature in the second subspace; Calculate the temperature difference between the set temperature of the gas water heater and the water temperature; The opening degree of the solenoid valve is adjusted according to the temperature difference, thereby regulating the water flow rate in the cold water pipe; The start and stop of the drive mechanism are controlled according to the water flow rate in the cold water pipe.

2. The control method according to claim 1, wherein... The step of adjusting the opening degree of the solenoid valve according to the temperature difference, thereby adjusting the water flow rate in the cold water pipe, includes: If the temperature difference is greater than the preset temperature difference value, the opening degree of the solenoid valve is adjusted to the preset maximum opening degree; If the temperature difference is less than or equal to the preset temperature difference, the opening of the solenoid valve is adjusted to the preset minimum opening. in The preset minimum opening is set so that the water flow in the cold water pipe is just enough to trigger the ignition system of the gas water heater to start.

3. The control method according to claim 2, wherein, The drive mechanism includes a motor located outside the tank, a helical rod connected to the motor and extending into the tank, and a telescopic rod that selectively retracts into or extends from the helical rod, the end of which is connected to the baffle. and The steps for controlling the start and stop of the drive mechanism based on the water flow rate in the cold water pipe include: Receive an ignition start signal, which is generated when the water flow rate in the cold water pipe reaches the preset ignition flow rate; Start the ignition system and control the motor to rotate in the forward direction.

4. The control method according to claim 3, wherein, If the opening degree of the solenoid valve is the preset minimum opening degree, then after starting the ignition system and controlling the motor to rotate in the forward direction, the control method of the present invention further includes: Obtain the water flow rate in the outlet pipe; Adjust the opening of the solenoid valve according to the water flow rate in the outlet pipe until the opening of the solenoid valve reaches the preset maximum opening; and The speed of the motor is adjusted according to the water flow rate in the outlet pipe and the opening degree of the solenoid valve, so as to adjust the speed of the baffle movement until the baffle moves to the preset position.

5. The control method according to claim 4, wherein The steps for adjusting the opening degree of the solenoid valve according to the water flow rate of the outlet pipe include: The opening degree of the solenoid valve is calculated using the following formula: y t =k×t+y0; where y t The value represents the opening degree of the solenoid valve at time t after receiving the ignition start signal, where t represents the water usage time since receiving the ignition start signal, y0 represents the preset minimum opening degree, and k represents a coefficient proportional to the user's water flow rate.

6. The control method according to claim 4, wherein The step of adjusting the motor speed according to the water flow rate in the outlet pipe and the opening degree of the solenoid valve to adjust the speed of the baffle movement includes: The water flow rate in the cold water pipe is calculated based on the opening degree of the solenoid valve; Calculate the flow rate difference between the water flow rate in the outlet pipe and the water flow rate in the cold water pipe; The target moving speed of the baffle is calculated using the following formula: Q0 = (Q1 - Q2) / S; where Q0 represents the flow difference, Q1 represents the water flow rate in the outlet pipe, Q2 represents the water flow rate in the cold water pipe, and S represents the cross-sectional area of ​​the tank. The target rotational speed of the motor is calculated based on the target moving speed of the baffle. as well as Control the motor to run at the target speed.

7. The control method according to claim 3, wherein If the opening degree of the solenoid valve is the preset maximum opening degree, after starting the ignition system and controlling the motor to rotate in the forward direction, the control method further includes: Control the motor to rotate forward at a preset minimum speed until the baffle moves to a preset position.

8. The control method according to claim 4 or 7, wherein After the baffle moves to the preset position, the control method further includes: Receive a water usage stop signal, the water usage stop signal being used to indicate that the water-using end has stopped using water; and Adjust the opening of the solenoid valve to a preset initial opening, and control the motor to rotate in the reverse direction; in The preset initial opening degree is greater than zero and less than the preset minimum opening degree.

9. The control method according to claim 8, wherein After receiving the water usage stop signal, the control method further includes: Receive an ignition stop signal, which is generated when the water flow rate in the cold water pipe is less than the preset ignition flow rate; as well as Stop the ignition system.

10. The control method according to claim 2, wherein The preset ignition flow rate is set to be greater than the maximum water flow rate in the cold water pipe when the cold water pipe is connected to the second subspace, and equal to or less than the minimum water flow rate in the cold water pipe when the cold water pipe is connected to the first subspace.

11. A gas water heater, comprising a heat exchanger, a cold water pipe connected to the upstream side of the heat exchanger, a hot water pipe connected to the downstream side of the heat exchanger, an inlet pipe for connecting to a tap water pipe, an outlet pipe for connecting to a water user, a solenoid valve disposed within the cold water pipe to adjust the flow area of ​​the cold water pipe, and an automatic thermostatic device, the automatic thermostatic device comprising a tank, a baffle and a temperature sensor disposed within the tank, and a drive mechanism; The baffle divides the space inside the tank into a fluid-isolated first subspace and a second subspace; the drive mechanism is connected to the baffle and is configured to controllably drive the baffle to move along the arrangement direction of the first subspace and the second subspace to adjust the volume of the first subspace and the second subspace; the temperature sensor is used to obtain the water temperature in the second subspace; The inlet pipe is connected to the first subspace, the hot water pipe and the outlet pipe are both connected to the second subspace, and the cold water pipe is configured to switch from being connected to the second subspace to being connected to the first subspace when water is used at the water-using end, and to switch from being connected to the first subspace to being connected to the second subspace when water is used at the water-using end; and The gas water heater further includes a control device electrically connected to the solenoid valve and the drive mechanism. The control device includes a processor and a memory. The memory stores a machine-executable program, and when executed by the processor, the machine-executable program is used to implement the control method according to any one of claims 1-10.

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