Control method and device for gas water heater and gas water heater

Abstract

The present invention relates to the technical field of water heater control, and discloses a control method and device for a gas water heater, and a gas water heater, including: when the gas water heater is ignited and combustion is stable, obtaining the outlet water temperature and current water flow rate of the heat exchange tube, and determining the target duration based on the current water flow rate, and then determining the pre-increase power; controlling the gas water heater to increase the target duration of the pre-increase power operation on the basis of the first power; when the target duration is reached, controlling the first bypass ratio to increase to the target bypass ratio, and controlling the gas water heater to directly drop to the first power before increasing the pre-increase power. The present invention quickly stores the energy of the heat exchange tube by increasing the pre-increase power and increasing the bypass ratio, providing backup energy for the next water boiling, and at the same time, by determining the target duration, controlling the duration and sequence of increasing the pre-increase power and increasing the bypass ratio, the water temperature fluctuation caused by increasing the bypass ratio and increasing the pre-increase power can be avoided.

Description

Technical Field

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

[0002] When the gas water heater is used, when the water is turned off for a short time and then used again, a period of hot water higher than the set temperature will be produced, followed by a period of cold water lower than the set temperature, and then the outlet water temperature is the target temperature set by the user. Therefore, the start and stop of water flow will inevitably cause fluctuations in the outlet water temperature, reducing the user's comfort experience.

[0003] To address this issue, related technologies manage and regulate the energy in the heat exchange tubes through bypass pipes, including the storage and timely release of this energy, to maintain the water temperature stability of the water heater after the second boiling of the water.

[0004] However, if there are multiple starts and stops within a certain period of time, the heat exchange tubes of the water heater will not have time to store energy, so that the heat exchange tubes will not have sufficient energy (i.e. overflow energy) for management and regulation when the water is boiled next time, which may ultimately have an adverse effect on the stability of the water outlet temperature and user experience. Summary of the invention

[0005] The first technical problem solved by the present invention is to provide a control method for a gas water heater, which effectively solves the problems of insufficient energy and water temperature fluctuation when the gas water heater is restarted.

[0006] The second technical problem solved by the present invention is to provide a control device for a gas water heater, which effectively solves the problems of insufficient energy and water temperature fluctuation when the gas water heater is restarted.

[0007] The third technical problem solved by the present invention is to provide a gas water heater which effectively solves the problem of water temperature fluctuation when replenishing overflow energy.

[0008] The first technical problem mentioned above is solved by the following technical solution:

[0009] A control method for a gas water heater, the method comprising:

[0010] When the gas water heater is ignited and combustion is stable, the outlet water temperature and current water flow rate of the heat exchange tube are obtained, and the target duration is determined based on the current water flow rate;

[0011] Determining the pre-increase power based on the outlet water temperature of the heat exchange tube, the target water temperature and the current water flow rate;

[0012] Controlling the gas water heater to increase the pre-increase power based on the first power to work for the target duration;

[0013] When the target duration is reached, the first bypass ratio is controlled to increase to the target bypass ratio, and the gas water heater is controlled to directly drop to the first power before the pre-increase power is increased.

[0014] Compared with the background technology, the control method of the gas water heater described in the present invention has the following beneficial effects: the method provided by the present invention quickly stores the energy of the heat exchange tube by increasing the pre-increase power and increasing the bypass ratio, providing backup energy for the next water boiling, and at the same time, by determining the target duration, controlling the duration and sequence of increasing the pre-increase power and increasing the bypass ratio, the water temperature fluctuation caused by increasing the bypass ratio and increasing the pre-increase power can be avoided.

[0015] In one embodiment, determining the target duration based on the current water flow rate includes:

[0016] Obtaining the volume of the water outlet pipe and a preset time, wherein the preset time is used to characterize the time for increasing the pre-increase power;

[0017] A first duration is obtained based on a ratio of the volume of the water outlet pipe to the current water flow rate, wherein the first duration is used to characterize the duration of the water flow from the water outlet of the heat exchange pipe to the mixing point, the water outlet pipe is used to characterize the water pipe from the water outlet of the heat exchange pipe to the mixing point, and the mixing point is used to characterize the connection point between the bypass pipe and the water outlet pipe;

[0018] The sum of the first duration and the preset duration is calculated to obtain the target duration.

[0019] In one embodiment, determining the pre-increase power based on the outlet water temperature of the heat exchange tube, the target water temperature and the current water flow rate includes:

[0020] Obtaining a first temperature difference based on the outlet water temperature of the heat exchange tube and the target water temperature;

[0021] Obtaining pre-increase energy based on the volume of the water outlet pipe, the volume of the heat exchange pipe and the first temperature difference;

[0022] The pre-increase power is obtained based on a ratio of the pre-increase energy to the first duration.

[0023] In one embodiment, obtaining the pre-increase energy based on the volume of the water outlet pipe, the volume of the heat exchange pipe and the first temperature difference includes:

[0024] respectively calculating the product of the volume of the water outlet pipe and the first temperature difference and the product of the volume of the heat exchange pipe and the first temperature difference;

[0025] The pre-increase energy is determined based on the product of the volume of the water outlet pipe and the first temperature difference and the product of the volume of the heat exchange pipe and the first temperature difference.

[0026] In one embodiment, obtaining the outlet water temperature of the heat exchange tube includes:

[0027] Determine the inlet and outlet water temperature difference based on the outlet water temperature and the inlet water temperature, and

[0028] The outlet water temperature of the heat exchange tube is calculated based on the first bypass ratio and the inlet and outlet water temperature difference; or,

[0029] The outlet water temperature of the heat exchange tube is determined based on a heat exchanger temperature sensor.

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

[0031] obtaining the target bypass ratio;

[0032] A target water temperature is determined based on the target bypass ratio, the outlet water temperature and the inlet water temperature of the heat exchange tube.

[0033] In one embodiment, controlling the first bypass ratio to increase to the target bypass ratio includes:

[0034] The first bypass ratio is increased to a target bypass ratio based on a bypass ratio adjusting component, wherein the bypass ratio adjusting component is a combined valve body composed of a plurality of on-off valves connected in parallel.

[0035] The above second technical problem is solved by the following technical solution:

[0036] A control device for a gas water heater, the device comprising:

[0037] The duration determination module is used to obtain the outlet water temperature and current water flow rate of the heat exchange tube when the gas water heater is ignited and the combustion is stable, and determine the target duration based on the current water flow rate;

[0038] A pre-increase power determination module, used to determine the pre-increase power based on the outlet water temperature of the heat exchange tube, the target water temperature and the current water flow rate;

[0039] A target power determination module, used for controlling the gas water heater to increase the pre-increase power to work for the target duration based on the first power;

[0040] The bypass ratio adjustment module is used to control the first bypass ratio to increase to the target bypass ratio when the target duration is reached, and control the gas water heater to directly drop to the first power before increasing the pre-increase power.

[0041] The third technical problem mentioned above is solved by the following technical solution:

[0042] A gas water heater comprises: a memory and a processor, wherein the memory and the processor are communicatively connected with each other, the memory stores computer instructions, and the processor executes the control method by executing the computer instructions.

[0043] A gas water heater, used to execute the above method, comprising: a heat exchanger, wherein the water inlet end of the heat exchanger is provided with a water inlet pipe, the water outlet end of the heat exchanger is provided with a water outlet pipe, and the heat exchange tube is provided inside the heat exchanger; a bypass ratio adjustment component, wherein the bypass ratio adjustment component is arranged in the bypass pipe, the bypass ratio adjustment component is a combined valve body composed of a plurality of switch valves connected in parallel, and the bypass pipe is respectively connected to the water inlet pipe and the water outlet pipe; and a water flow sensor, wherein the water flow sensor is arranged at the water inlet end of the water inlet pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 A schematic diagram of a gas water heater according to an embodiment of the present invention Figure 1 ;

[0046] Figure 2 A schematic diagram of a gas water heater according to an embodiment of the present invention Figure 2 ;

[0047] Figure 3 A flow chart of a method for controlling a gas water heater according to an embodiment of the present invention;

[0048] Figure 4 Schematic diagram of a gas water heater according to an embodiment of the present invention Figure 3 ;

[0049] Figure 5 This is a schematic diagram of the initial energy state of an embodiment of the present invention;

[0050] Figure 6 A schematic diagram of energy states of increasing pre-increase power in an embodiment of the present invention;

[0051] Figure 7 This is a schematic diagram of energy status after increasing the target duration of pre-increase power operation according to an embodiment of the present invention;

[0052] Figure 8 Schematic diagram of a control device for a gas water heater according to an embodiment of the present invention.

[0053] Description of reference numerals:

[0054] 101. Heat exchanger; 102. Bypass ratio adjustment component; 103. Water flow sensor; 104. Water inlet temperature sensor; 105. Water tank temperature sensor; 106. Water outlet temperature sensor; 107. Water mixing tank; 1011. Heat exchange tube. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0056] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0057] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0058] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0059] In the related art, in order to ensure that the water heater has sufficient backup energy at the beginning of the next use cycle, energy replenishment is usually performed by increasing the bypass ratio. Increasing the bypass ratio may cause an energy gap, causing the outlet water temperature to fluctuate, affecting the user experience. Based on this, the present invention provides a control method for a gas water heater to solve the above problem.

[0060] The control method of the gas water heater provided in the embodiment of the present application can be applied to Figure 1 The gas water heater shown, Figure 1 A schematic diagram of a gas water heater according to an embodiment of the present invention Figure 1 The gas water heater includes a heat exchanger 101, a bypass ratio adjustment component 102, and a water flow sensor 103. The water inlet end of the heat exchanger 101 is provided with a water inlet pipe, the water outlet end of the heat exchanger 101 is provided with a water outlet pipe, and a heat exchange tube 1011 is provided inside the heat exchanger 101. The bypass ratio adjustment component 102 is arranged in the bypass pipe, and the bypass pipe is connected to the water inlet pipe and the water outlet pipe respectively. The bypass ratio adjustment component 102 is a combined valve body composed of multiple switch valves in parallel. The water flow sensor 103 is arranged at the water inlet end of the water inlet pipe, and is used to measure the water flow of the inlet water. The bypass ratio adjustment component 102 can adjust the bypass ratio as needed. Since the bypass ratio adjustment component 102 is a combined valve body, each unit of which is a switch valve, the bypass ratio adjustment component 102 can adjust the bypass ratio by controlling the parallel working state of multiple switch valves. Since the switch valve has the characteristics of full opening or full closing, and the valves are connected in parallel, the adjustment process is highly direct and rapid. When an adjustment command is received, the corresponding switch valve will respond immediately and open or close according to the adjustment command to achieve rapid adjustment of the bypass ratio.

[0061] In one embodiment, the gas water heater is further provided with an inlet water temperature sensor 104, a water tank temperature sensor 105, and an outlet water temperature sensor 106. The inlet water temperature sensor 104 is provided at the water inlet end of the water inlet pipe, and is used to measure the inlet water temperature of the water inlet. The water tank temperature sensor 105 is provided at the water outlet end of the heat exchanger 101, and is used to measure the outlet water temperature of the heat exchange pipe. The outlet water temperature sensor 106 is provided at the outlet end of the outlet pipe, and is used to measure the outlet water temperature.

[0062] In one embodiment, Figure 2 As shown, Figure 2 A schematic diagram of a gas water heater according to an embodiment of the present invention Figure 2 A water mixing tank 107 may be provided at the intersection of the bypass pipe and the water outlet pipe to store water flowing out of the bypass pipe and the water outlet pipe.

[0063] According to an embodiment of the present invention, a control method for a gas water heater is provided, which can be used for the above-mentioned gas water heater. Figure 3 is a flow chart of a control method for a gas water heater according to an embodiment of the present invention. Figure 3 As shown, the process includes the following steps:

[0064] Step S101, when the gas water heater is ignited and combustion is stable, the outlet water temperature of the heat exchange tube and the current water flow rate are obtained, and the target duration is determined based on the current water flow rate.

[0065] This method is used in the scenario after the gas water heater is restarted. When the gas water heater is started and turned off, it is restarted in a short time. According to the received start signal (for example, turning on the tap), the ignition system will immediately respond to the ignition and run. At this time, the outlet water temperature of the heat exchanger and the current water flow rate are obtained. The current water flow rate can be adjusted by the user, and the current water flow rate can be measured by the water flow sensor set at the water inlet end of the water inlet pipe. The outlet water temperature of the heat exchange tube can be directly measured by the corresponding temperature sensor, or it can be calculated based on the current bypass ratio and the inlet and outlet water temperature difference, which is not specifically limited in this embodiment.

[0066] The connection point between the bypass pipe and the outlet pipe is called the mixing point. The target duration includes at least the duration of the heat exchange pipe power increase, the duration of water heating, and the duration of water flowing from the outlet of the heat exchange pipe to the mixing point after being heated. The duration of water flowing from the outlet of the heat exchange pipe to the mixing point after being heated can be calculated based on the current water flow rate and the parameters of the outlet pipe in the high-temperature section. Figure 4 A schematic diagram of a gas water heater according to an embodiment of the present invention Figure 3 , the outlet pipe of the high temperature section is as follows Figure 4 As shown, it is the part from the outlet pipe to the mixing point. The parameters of the outlet pipe in the high temperature section include the cross-sectional radius and length of the outlet pipe, or it can be directly the volume of the outlet pipe in the high temperature section that has been pre-stored, and there is no specific limitation. The power increase time of the heat exchange tube and the heating time of the heat exchange tube for water need to be determined in combination with the power of the heat exchange tube. The corresponding relationship between the heating power of the heat exchange tube and the corresponding time can be pre-stored in advance according to the experiment, and then this part of the time can be directly determined according to the heating power.

[0067] Step S102, determining the pre-increase power based on the outlet water temperature of the heat exchange tube, the target water temperature and the current water flow rate.

[0068] The target water temperature refers to the temperature of the water flowing out of the water outlet pipe, which is the temperature after the hot water flowing out of the water outlet of the heat exchange tube and the water flowing out of the bypass pipe are mixed. The target water temperature can be calculated by the corresponding target bypass ratio, or the corresponding relationship between the target water temperature and the set water temperature can be determined in advance by testing and the corresponding relationship is stored, and then the corresponding target water temperature is determined according to the set water temperature. In order to replenish the overflow energy after the gas water heater is started again, the bypass ratio needs to be increased to the target bypass ratio, so the target bypass ratio is a pre-set value. There is a corresponding relationship between the bypass ratio, the inlet water temperature, the outlet water temperature and the outlet water temperature of the heat exchange tube. Therefore, when the target bypass ratio, the inlet water temperature and the outlet water temperature of the heat exchange tube are known, the target water temperature can be calculated according to the corresponding relationship. Among them, the inlet water temperature can be measured according to the inlet water temperature sensor provided at the inlet end of the inlet pipe.

[0069] The outlet water temperature of the heat exchange tube is increased so that the outlet water temperature reaches the target water temperature. The outlet water temperature of the heat exchange tube is increased by increasing the heating power of the gas water heater. The pre-increase power is the power change that the gas water heater needs to increase. Increasing the pre-increase power is used to make up for the energy gap caused by the subsequent increase in the bypass ratio in advance. The pre-increase power can be obtained by calculating the ratio of the energy change to the target duration. Furthermore, the energy change can be calculated from the outlet water temperature of the heat exchange tube and the target water temperature. The size parameters of the heat exchange tube and the high-temperature section outlet water pipe can also be used in the calculation process. The calculation method of the pre-increase power is specifically described in the following embodiment.

[0070] Step S103, controlling the gas water heater to increase the target working time of the pre-increase power based on the first power.

[0071] The first power is the initial heating power of the gas water heater. The pre-increase power is increased on the basis of the first power, and the gas water heater is controlled to operate at the increased power.

[0072] Step S104, when the target duration is reached, the first bypass ratio is controlled to increase to the target bypass ratio, and the gas water heater is controlled to directly decrease to the first power before the pre-increase power is increased.

[0073] The first bypass ratio represents the initial bypass ratio, and the size of the first bypass ratio can be 0. If the gas water heater continues to work for a target duration with the power increased by the pre-increased power, the heated water flows from the outlet of the heat exchange tube to the mixing point, the first bypass ratio is increased to the target bypass ratio, and the power is reduced to the first power, and the bypass ratio and the power are adjusted to be consistent. In this embodiment, the bypass ratio is directly increased, and the power is directly reduced to the first power.

[0074] The control method of the gas water heater provided in the embodiment of the present invention obtains the outlet water temperature and the current water flow rate of the heat exchange tube when the gas water heater is ignited and the combustion is stable, and determines the target duration based on the current water flow rate; determines the pre-increase power based on the outlet water temperature of the heat exchange tube, the target water temperature and the current water flow rate; controls the gas water heater to increase the target duration of the pre-increase power operation on the basis of the first power; when the target duration is reached, controls the first bypass ratio to increase to the target bypass ratio, and controls the gas water heater to directly drop to the first power before increasing the pre-increase power. The method provided in this embodiment quickly stores the energy of the heat exchange tube by increasing the pre-increase power and increasing the bypass ratio, and provides backup energy for the next water boiling. At the same time, by determining the target duration, controlling the duration and sequence of increasing the pre-increase power and increasing the bypass ratio, the water temperature fluctuation caused by increasing the bypass ratio and increasing the pre-increase power can be avoided.

[0075] It should be noted that this embodiment first increases the pre-increase power to quickly store the energy of the heat exchange tube, calculates the target duration by the water flow rate, and can quickly increase the bypass ratio and cancel the pre-increase power when the hot water after the pre-increase power flows to the mixing point, so as to prevent the hot water after the pre-increase power from being too hot and causing water temperature fluctuations. If the pre-increase power is simply increased or the bypass ratio is quickly increased, the water temperature of the water supply will inevitably fluctuate. And because the bypass ratio is quickly increased, the amount of cold water flowing to the heat exchange tube becomes less. Therefore, even if the gas water heater uses the power before canceling the pre-increase power for combustion, the water temperature in the heat exchange tube is higher than the water temperature before increasing the pre-increase power, so that the energy of the heat exchange tube can continue to be stored, providing energy for the next water boiling, and management and regulation.

[0076] See also Figures 5 to 7 Energy state diagram, Figure 5 Schematic diagram of the initial energy state, indicating the energy state before the initial bypass ratio increases, and the initial bypass ratio is 0. Figure 6 It is a schematic diagram of the energy state of increasing the pre-increase power, which indicates the energy change of the gas water heater when the pre-increase power is increased on the basis of the first power. The shaded area different from the basic energy indicates the size of the pre-increase energy. Figure 7 It is a schematic diagram of the energy state after increasing the pre-increase power working target duration, which represents the pre-increase energy state after controlling the gas water heater to increase the pre-increase power working target duration on the basis of the first power. At the mixing point, the power directly drops to the first power before the pre-increase power, and at the same time, the initial bypass ratio directly increases to the target bypass ratio.

[0077] In one embodiment, the step S104 of controlling the first bypass ratio to increase to the target bypass ratio in the above embodiment includes: increasing the first bypass ratio to the target bypass ratio based on a bypass ratio adjustment component, wherein the bypass ratio adjustment component is a combined valve body composed of a plurality of switch valves connected in parallel.

[0078] The bypass ratio adjustment component can adjust the bypass ratio by controlling the parallel working state of multiple switch valves. Since the switch valve has the characteristics of full open or full closed, and the valves are connected in parallel, the adjustment process is highly direct and rapid. When receiving an adjustment command, the corresponding switch valve will respond immediately and open or close according to the adjustment command to achieve rapid adjustment of the bypass ratio.

[0079] In one embodiment, the step S101 in the above embodiment, determining the target duration based on the current water flow, includes the following steps:

[0080] Step S201, obtaining the volume of the water outlet pipe and the preset duration.

[0081] The preset duration is used to represent the duration of increasing the pre-boost power.

[0082] It takes a certain amount of time to control the heat exchange tube to increase the pre-increase power and heat the water. This time period is the preset time period.

[0083] The outlet pipe in this step refers to the outlet pipe of the high temperature section. The volume of the outlet pipe can be determined by the cross-sectional radius and length of the outlet pipe, or the volume of the outlet pipe of the high temperature section can be pre-stored.

[0084] When the heat exchange tube increases the power, it also heats the water. When the heating power is increased, the heating process needs a certain amount of time to respond to the change in power and reach a new steady state (i.e., the water temperature reaches a new equilibrium state). It can be determined based on the actual pre-increase power and the preset power change rate. It can also be calculated and determined in advance by experiment to determine the correspondence between the pre-increase power and the duration, and the correspondence is stored. According to the actual pre-increase power, the corresponding preset duration can be directly determined based on the correspondence. Step S202, the first duration is obtained based on the ratio of the outlet pipe volume to the current water flow rate.

[0085] The first duration is used to characterize the duration of water flow from the outlet of the heat exchange tube to the mixing point, the outlet pipe is used to characterize the water pipe from the outlet of the heat exchange tube to the mixing point, and the mixing point is used to characterize the connection point between the bypass pipe and the outlet pipe.

[0086] For example, if the length of the outlet pipe of the high-temperature section is L1, the radius is R1, and the current water flow rate is v, the first time length = (L1×π×R1²) / v.

[0087] Step S203, calculating the sum of the first duration and the preset duration to obtain the target duration.

[0088] The target duration is the sum of the first duration and the preset duration.

[0089] In one embodiment, step S102 in the above embodiment includes the following steps:

[0090] Step S301, obtaining a first temperature difference based on the outlet water temperature of the heat exchange tube and the target water temperature.

[0091] When Th represents the outlet water temperature of the heat exchange tube, Tc represents the target water temperature, and the first temperature difference = Th-Tc.

[0092] Step S302, obtaining pre-increase energy based on the volume of the water outlet pipe, the volume of the heat exchange pipe and the first temperature difference.

[0093] Further, step S302 includes the following steps:

[0094] Step S3021, respectively calculating the product of the water pipe volume and the first temperature difference and the product of the heat exchange tube volume and the first temperature difference.

[0095] Step S3022: determine the pre-increase energy based on the product of the volume of the water outlet pipe and the first temperature difference and the product of the volume of the heat exchange tube and the first temperature difference.

[0096] In order to make up for the energy gap caused by increasing the bypass ratio, the pre-increase energy is increased by increasing the heating power. Specifically, the pre-increase energy = L0×π×R0²×(Th-Tc) / 2+L1×π×R1²×(Th-Tc), where L0 represents the length of the heat exchange tube, R0 represents the radius of the heat exchange tube, L1 represents the length of the water outlet pipe, and R1 represents the radius of the water outlet pipe.

[0097] Step S303: obtaining the pre-increase power based on the ratio of the pre-increase energy to the first duration.

[0098] Specifically, the first time length = (L1×π×R1²) / v. According to the pre-increase energy in the above steps, the pre-increase power can be obtained as (L0×π×R0²×(Th-Tc) / 2+L1×π×R1²×(Th-Tc)) / (L1×π×R1² / v).

[0099] In one embodiment, the outlet water temperature of the heat exchange tube is obtained in step S101 of the above embodiment, including: determining the inlet and outlet water temperature difference based on the outlet water temperature and the inlet water temperature, and calculating the outlet water temperature of the heat exchange tube based on the first bypass ratio and the inlet and outlet water temperature difference; or, determining the outlet water temperature of the heat exchange tube based on the heat exchanger temperature sensor.

[0100] There is a corresponding relationship between the bypass ratio, the inlet water temperature, the outlet water temperature and the outlet water temperature of the heat exchange tube. Specifically, the corresponding relationship between the bypass ratio, the inlet water temperature, the outlet water temperature and the outlet water temperature of the heat exchange tube is as follows:

[0101] P=1-(Tc-Tj) / (Th-Tj)

[0102] Wherein, P represents the bypass ratio, Tc represents the outlet water temperature, Tj represents the inlet water temperature, and Th represents the outlet water temperature of the heat exchange tube.

[0103] In this embodiment, the outlet water temperature corresponds to the first bypass ratio, which is the outlet water temperature before increasing the heating power and adjusting the bypass ratio, and can be measured by the outlet water temperature sensor provided at the outlet end of the outlet pipe, and the inlet water temperature can be measured by the inlet water temperature sensor provided at the inlet end of the water inlet. By the known first bypass ratio, inlet water temperature and outlet water temperature, the inlet and outlet water temperature difference = Tc-Tj, and the outlet water temperature of the heat exchange tube is calculated according to the above formula.

[0104] The heat exchanger temperature sensor, that is, the water tank temperature sensor, is arranged at the water outlet of the heat exchange tube, and can also be directly measured by the heat exchanger temperature sensor.

[0105] In one embodiment, the control method of the gas water heater in the above embodiment further includes the following steps:

[0106] Step S501: Obtain a target bypass ratio.

[0107] In order to replenish the overflow energy after the gas water heater is restarted, the bypass ratio needs to be increased to the target bypass ratio, so the target bypass ratio is a preset value, and the target bypass ratio is stored in advance.

[0108] Step S502: Determine the target water temperature based on the target bypass ratio, the outlet water temperature of the heat exchange tube, and the inlet water temperature.

[0109] The target water temperature refers to the temperature of the water flowing out of the outlet pipe, which is the temperature after the hot water flowing out of the outlet of the heat exchange tube and the water flowing out of the bypass pipe are mixed. There is a corresponding relationship between the bypass ratio, the inlet water temperature, the outlet water temperature and the outlet water temperature of the heat exchange tube.

[0110] Specifically, the corresponding relationship between the bypass ratio, the inlet water temperature, the outlet water temperature and the outlet water temperature of the heat exchange tube is as follows:

[0111] P=1-(Tc-Tj) / (Th-Tj)

[0112] Wherein, P represents the bypass ratio, Tc represents the outlet water temperature, Tj represents the inlet water temperature, and Th represents the outlet water temperature of the heat exchange tube.

[0113] When the target bypass ratio, water inlet temperature and water outlet temperature of the heat exchange tube are known, the target water temperature (i.e., water outlet temperature) can be calculated according to the above corresponding relationship. The water inlet temperature can be measured by a water inlet temperature sensor provided at the water inlet end of the water inlet pipe.

[0114] In this embodiment, a control device for a gas water heater is also provided, which is used to implement the above-mentioned embodiments and implementation methods, and the descriptions that have been made will not be repeated. As used below, the term "module" can implement a combination of software and / or hardware of a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0115] This embodiment provides a control device for a gas water heater, such as Figure 8 As shown, including:

[0116] The duration determination module 601 is used to obtain the outlet water temperature and current water flow rate of the heat exchange tube when the gas water heater is ignited and the combustion is stable, and determine the target duration based on the current water flow rate;

[0117] A pre-increase power determination module 602 is used to determine the pre-increase power based on the outlet water temperature of the heat exchange tube, the target water temperature and the current water flow rate;

[0118] A target power determination module 603 is used to control the gas water heater to increase the pre-increase power to work for the target duration based on the first power;

[0119] The bypass ratio adjustment module 604 is used to control the first bypass ratio to increase to the target bypass ratio when the target duration is reached, and control the gas water heater to directly drop to the first power before increasing the pre-increase power.

[0120] In one embodiment, the duration determination module 601 includes:

[0121] A volume acquisition unit, used to acquire the volume of the water outlet pipe and a preset time, wherein the preset time is used to represent the time for increasing the pre-increase power;

[0122] a first duration calculation unit, configured to obtain a first duration based on a ratio of the volume of the water outlet pipe to the current water flow rate, wherein the first duration is used to characterize the duration of the water flow from the water outlet of the heat exchange pipe to the mixing point, wherein the water outlet pipe is used to characterize the water pipe from the water outlet of the heat exchange pipe to the mixing point, and the mixing point is used to characterize the connection point between the bypass pipe and the water outlet pipe;

[0123] The target duration calculation unit is used to calculate the sum of the first duration and the preset duration to obtain the target duration.

[0124] In one embodiment, the pre-increase power determination module 602 includes:

[0125] A first temperature difference calculation unit, configured to obtain a first temperature difference based on the outlet water temperature of the heat exchange tube and the target water temperature;

[0126] a pre-increase energy determination unit, configured to obtain the pre-increase energy based on the volume of the water outlet pipe, the volume of the heat exchange pipe and the first temperature difference;

[0127] A pre-increase power determination unit is used to obtain the pre-increase power based on a ratio of the pre-increase energy to the first duration.

[0128] In one embodiment, the pre-increase energy determination unit includes:

[0129] a product calculation subunit, used to calculate the product of the volume of the water outlet pipe and the first temperature difference and the product of the volume of the heat exchange pipe and the first temperature difference respectively;

[0130] The pre-increase energy calculation subunit is used to determine the pre-increase energy based on the product of the volume of the water outlet pipe and the first temperature difference and the product of the volume of the heat exchange tube and the first temperature difference.

[0131] In one embodiment, the duration determination module 601 includes:

[0132] an inlet and outlet water temperature difference determining unit, configured to determine the inlet and outlet water temperature difference based on the outlet water temperature and the inlet water temperature, and calculate the outlet water temperature of the heat exchange tube based on the first bypass ratio and the inlet and outlet water temperature difference;

[0133] The temperature measuring unit is used to determine the outlet water temperature of the heat exchange tube based on the heat exchanger temperature sensor.

[0134] In one embodiment, the apparatus further comprises:

[0135] a target bypass ratio obtaining unit, configured to obtain the target bypass ratio;

[0136] The target water temperature determination unit is used to determine the target water temperature based on the target bypass ratio, the outlet water temperature and the inlet water temperature of the heat exchange tube.

[0137] In one embodiment, the bypass ratio adjustment module 604 is further configured to increase the first bypass ratio to a target bypass ratio based on a bypass ratio adjustment component, wherein the bypass ratio adjustment component is a combined valve body formed by a plurality of switch valves connected in parallel.

[0138] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0139] The control device of the gas water heater in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0140] An embodiment of the present invention also provides a gas water heater having the control device of the above-mentioned gas water heater. The gas water heater includes: one or more processors, a memory, and an interface for connecting various components, including a high-speed interface and a low-speed interface. The various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process instructions executed in the gas water heater, including instructions stored in or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple gas water heaters can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system).

[0141] The processor may be a central processing unit, a network processor or a combination thereof. The processor may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0142] The memory stores instructions executable by at least one processor, so that the at least one processor executes the method shown in the above embodiment.

[0143] The memory may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required by at least one function; the data storage area may store data created according to the use of the gas water heater, etc. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the gas water heater via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0144] The memory may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid state drive; the memory may also include a combination of the above types of memory. The gas water heater also includes a communication interface for communicating with other devices or communication networks.

[0145] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0146] In the specific contents of the above-mentioned specific implementation methods, the various technical features can be combined in any non-contradictory manner. In order to make the description concise, not all possible combinations of the above-mentioned technical features are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0147] The specific contents of the above specific embodiments only express several embodiments of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A control method for a gas water heater, the control method is used in a scenario where the gas water heater is started and shut down and then restarted within a short period of time, characterized in that: The gas water heater comprises a heat exchanger, a water inlet pipe is provided at the water inlet end of the heat exchanger, a water outlet pipe is provided at the water outlet end of the heat exchanger, and a heat exchange pipe is provided inside the heat exchanger; a bypass ratio adjustment component is provided in the bypass pipe, the bypass ratio adjustment component is a combined valve body composed of a plurality of switch valves connected in parallel, and the bypass pipe is connected to the water inlet pipe and the water outlet pipe respectively; A water flow sensor, wherein the water flow sensor is disposed at the water inlet end of the water inlet pipe, and the method comprises: When the gas water heater is ignited and combustion is stable, the outlet water temperature and current water flow rate of the heat exchange tube are obtained, and the target duration is determined based on the current water flow rate; Determine the pre-increase power based on the outlet water temperature of the heat exchange tube, the target water temperature and the current water flow rate, wherein the target water temperature is the temperature after the hot water flowing out of the outlet of the heat exchange tube and the water flowing out of the bypass pipe are mixed; Control the gas water heater to increase the pre-increase power to work for the target duration based on the first power, where the first power is the initial heating power of the gas water heater; When the target duration is reached, controlling the first bypass ratio to increase to the target bypass ratio, and controlling the gas water heater to directly decrease to the first power before increasing the pre-increase power, wherein the first bypass ratio represents the initial bypass ratio; The determining of the target duration based on the current water flow rate includes: obtaining the volume of the high-temperature section water outlet pipe and a preset duration, wherein the preset duration is used to characterize the duration of increasing the pre-increase power; obtaining a first duration based on the ratio of the volume of the high-temperature section water outlet pipe to the current water flow rate, wherein the first duration is used to characterize the duration of the water flow from the water outlet of the heat exchange tube to the mixing point, wherein the high-temperature section water outlet pipe is used to characterize the water pipe from the water outlet of the heat exchange tube to the mixing point, and the mixing point is used to characterize the connection point between the bypass pipe and the water outlet pipe; calculating the sum of the first duration and the preset duration to obtain the target duration; The pre-increase power is determined based on the outlet water temperature of the heat exchange tube, the target water temperature and the current water flow rate, including: obtaining a first temperature difference based on the outlet water temperature of the heat exchange tube and the target water temperature; obtaining a pre-increase energy based on the volume of the high-temperature section outlet water pipe, the volume of the heat exchange tube and the first temperature difference; and obtaining the pre-increase power based on the ratio of the pre-increase energy to the first time length.

2. The method according to claim 1, characterized in that The obtaining of the pre-increase energy based on the volume of the high temperature section water outlet pipe, the volume of the heat exchange pipe and the first temperature difference comprises: respectively calculating the product of the volume of the high temperature section water outlet pipe and the first temperature difference and the product of the volume of the heat exchange tube and the first temperature difference; The pre-increase energy is determined based on the product of the volume of the high-temperature section water outlet pipe and the first temperature difference and the product of the volume of the heat exchange tube and the first temperature difference.

3. The method according to claim 1, characterized in that: The step of obtaining the outlet water temperature of the heat exchange tube comprises: Determine the inlet and outlet water temperature difference based on the outlet water temperature and the inlet water temperature, and calculate the outlet water temperature of the heat exchange tube based on the first bypass ratio and the inlet and outlet water temperature difference; or, The outlet water temperature of the heat exchange tube is determined based on a heat exchanger temperature sensor.

4. The method according to claim 1, characterized in that: The method further comprises: obtaining the target bypass ratio; A target water temperature is determined based on the target bypass ratio, the outlet water temperature and the inlet water temperature of the heat exchange tube.

5. The method according to claim 1, characterized in that The controlling the first bypass ratio to increase to the target bypass ratio includes: The first bypass ratio is increased to a target bypass ratio based on the bypass ratio adjustment component.

6. A control device for a gas water heater, used to implement the control method for a gas water heater according to any one of claims 1 to 5, characterized in that: The device comprises: The duration determination module is used to obtain the outlet water temperature and current water flow rate of the heat exchange tube when the gas water heater is ignited and the combustion is stable, and determine the target duration based on the current water flow rate; A pre-increase power determination module, used to determine the pre-increase power based on the outlet water temperature of the heat exchange tube, the target water temperature and the current water flow rate; A target power determination module, used for controlling the gas water heater to increase the pre-increase power to work for the target duration based on the first power; The bypass ratio adjustment module is used to control the first bypass ratio to increase to the target bypass ratio when the target duration is reached, and control the gas water heater to directly drop to the first power before increasing the pre-increase power.

7. A gas water heater, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the control method of the gas water heater according to any one of claims 1 to 5 by executing the computer instructions.

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