Control method of gas water heater and gas water heater

Abstract

The invention relates to the technical field of water heater control, and discloses a control method of a gas water heater and the gas water heater. The control method comprises the steps that the water outlet temperature and the current water flow of a heat exchange pipe are obtained, the target duration is determined based on the current water flow, and then the pre-increased power is determined; controlling the gas water heater to increase the work target duration of the pre-increased power at a first preset rate on the basis of the first power; and under the condition that the target duration is reached, the first bypass ratio is controlled to be increased to the target bypass ratio, and the gas water heater is controlled to be reduced to the first power at the first preset speed. The energy of the heat exchange tube is quickly stored by increasing the pre-increased power and increasing the bypass ratio, the energy vacancy caused by the increase of the bypass ratio is made up, standby energy is provided for the next time of boiling water, and meanwhile the target duration and the first preset rate are determined. And the duration and sequence of increasing the pre-increased power, reducing the pre-increased power and increasing the bypass ratio are controlled, the adjusting speed of the pre-increased power is adjusted, and water temperature fluctuation is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of water heater control, and in particular to a control method 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] In order to address this problem, relevant technologies manage and regulate the excess 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 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 excess energy, and thus the heat exchange tubes will not have sufficient backup 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 to solve 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 gas water heater to solve the problems of insufficient energy and water temperature fluctuation when the gas water heater is restarted.

[0007] The first technical problem mentioned above is solved by the following technical solution:

[0008] A control method for a gas water heater, characterized in that the method comprises:

[0009] 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;

[0010] 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;

[0011] Control the gas water heater to increase the pre-increase power at a first preset rate based on the first power to work for the target duration;

[0012] When the time duration from starting to control the gas water heater to increase the pre-increase power at a first preset rate on the basis of the first power reaches the target time duration, the first bypass ratio is controlled to increase to the target bypass ratio, and the gas water heater is controlled to decrease to the first power at a first preset rate.

[0013] 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, makes up for the energy vacancy caused by the increase in the bypass ratio, and provides backup energy for the next water boiling. At the same time, by determining the target duration and the first preset rate, the duration and sequence of increasing the pre-increase power, reducing the pre-increase power and increasing the bypass ratio, as well as the adjustment speed of increasing the pre-increase power and reducing the pre-increase power, can also avoid water temperature fluctuations caused by increasing the bypass ratio, increasing the pre-increase power and reducing the pre-increase power.

[0014] In one embodiment, the first preset rate is obtained according to the first bypass ratio, the target bypass ratio and the pre-boost power.

[0015] In one embodiment, the first preset rate is obtained according to the first bypass ratio, the target bypass ratio and the pre-increase power, including:

[0016] Determining a bypass ratio adjustment duration based on the target bypass ratio, the first bypass ratio, and a second preset rate;

[0017] A first preset rate is obtained based on a ratio of the pre-increase power to the bypass ratio adjustment time.

[0018] In one embodiment, determining the target duration based on the current water flow rate includes:

[0019] 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;

[0020] 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;

[0021] The sum of the first duration and the preset duration is calculated to obtain the target duration.

[0022] 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:

[0023] Obtaining a first temperature difference based on the outlet water temperature of the heat exchange tube and the target water temperature;

[0024] 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;

[0025] The pre-increase power is obtained based on a ratio of the pre-increase energy to the first duration.

[0026] 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:

[0027] 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;

[0028] 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.

[0029] In one embodiment, obtaining the outlet water temperature of the heat exchange tube includes:

[0030] 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,

[0031] The outlet water temperature of the heat exchange tube is determined based on a heat exchanger temperature sensor.

[0032] In one embodiment, the method further comprises:

[0033] obtaining the target bypass ratio;

[0034] 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.

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

[0036] A gas water heater, characterized in that it is used to perform the above method, comprising:

[0037] A heat exchanger, wherein 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 pipe, wherein the bypass pipe is respectively connected to the water inlet pipe and the water outlet pipe; a bypass ratio adjusting component, wherein the bypass ratio adjusting component is arranged on the bypass pipe; and a water flow sensor, wherein the water flow sensor is arranged at the water inlet end of the water inlet end.

[0038] In one embodiment, the bypass ratio adjustment component is a water proportional valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] 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.

[0040] Figure 1 A schematic diagram of a gas water heater according to an embodiment of the present invention;

[0041] Figure 2 A schematic diagram of another gas water heater according to an embodiment of the present invention;

[0042] Figure 3 A schematic diagram of another gas water heater according to an embodiment of the present invention;

[0043] Figure 4 A schematic diagram of another gas water heater according to an embodiment of the present invention;

[0044] Figure 5 A flow chart of a method for controlling a gas water heater according to an embodiment of the present invention;

[0045] Figure 6 A schematic diagram of a gas water heater according to an embodiment of the present invention;

[0046] Figure 7 It is a schematic diagram of energy state of an embodiment of the present invention;

[0047] Figure 8 It is a schematic diagram of energy state of an embodiment of the present invention;

[0048] Fig. 9 It is a schematic diagram of energy state of an embodiment of the present invention;

[0049] Fig.10 It is a schematic diagram of energy state of an embodiment of the present invention;

[0050] Fig.11 Schematic diagram of the relationship between power and tube length according to an embodiment of the present invention.

[0051] Description of reference numerals:

[0052] 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

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] In the related art, in order to ensure that the water heater has sufficient spare thermal energy when the next use cycle is started, the traditional approach is to increase the bypass ratio to replenish energy. In order to ensure the stability of the outlet water temperature, the energy is replenished slowly, that is, the bypass ratio is slowly adjusted. This approach of increasing the bypass ratio may cause insufficient energy supply, which in turn leads to unstable fluctuations in the outlet water temperature of the hot water, and ultimately has an adverse effect on the user's comfort experience. Based on this, an embodiment of the present invention provides a control method for a gas water heater to solve the above problem.

[0058] The control method of the gas water heater provided in the embodiment of the present application can be applied to Figure 1The gas water heater shown in FIG. 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 pipe 1011 is provided inside the heat exchanger 101. The bypass ratio adjustment component 102 is provided in the bypass pipe, and the bypass pipe is connected to the water inlet pipe and the water outlet pipe respectively. The specific position of the bypass ratio adjustment component 102 is not limited. For example, it can be as follows Figure 1 As shown, it is arranged at the connection between the bypass pipe and the water inlet pipe; it can also be as Figure 2 As shown, it is arranged on the bypass pipe. 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.

[0059] In one embodiment, the bypass ratio adjustment component 102 is a water proportional valve.

[0060] The use of a water proportional valve as the bypass ratio adjustment component 102 can accurately control the water flow through the bypass pipe, maintain the stability of the outlet water temperature, and reduce water temperature fluctuations.

[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 3 and Figure 4 As shown, 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 5 is a flow chart of a control method for a gas water heater according to an embodiment of the present invention. Figure 5 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 applied to the scenario after the gas water heater is restarted. Specifically, after the gas water heater is turned off for a period of time, if it is turned on again within a short period of time, it means that it is restarted. After the gas water heater receives the start signal, the ignition system will immediately respond to the start command and run. Stable combustion indicates that it has started normally and started to run. 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. In this embodiment, the method of obtaining the outlet water temperature of the heat exchange tube is not specifically limited. The current water flow rate can be the default water flow rate after it is turned on, or it can be adjusted by the user. The current water flow rate can be measured by a water flow sensor set at the water inlet end of the water inlet pipe.

[0066] The mixing point is used to characterize the connection point between the bypass pipe and the outlet pipe. 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 of the high temperature section. Figure 6 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 pre-increase power working target duration at a first preset rate based on the first power.

[0071] The first power is the initial heating power of the gas water heater. The heating power is increased by increasing the pre-increase power at a first preset rate on the basis of the first power.

[0072] The gas water heater is controlled to operate at a power obtained by increasing the pre-increase power by the first power, and the continuous operating time reaches at least the target time.

[0073] Step S104, when the time from starting to control the gas water heater to increase the pre-increase power at a first preset rate on the basis of the first power reaches the target time, the first bypass ratio is controlled to increase to the target bypass ratio, and the gas water heater is controlled to decrease to the first power at the first preset rate.

[0074] The first bypass ratio represents the initial bypass ratio, and the size of the first bypass ratio can be 0. If the continuous working time of the gas water heater after the pre-increase power is increased at the first preset rate reaches the target time, the heated water flows from the outlet of the heat exchange tube to the mixing point, and the first bypass ratio is increased to the target bypass ratio, and the gas water heater is controlled to decrease to the first power at the first preset rate. In order to ensure that the water temperature does not fluctuate, the time for controlling the bypass ratio to increase is consistent with the time for controlling the power to decrease, and the rate of adjusting the bypass ratio can be pre-set as a fixed value, so the first preset rate of power decrease can be calculated by the first bypass ratio and the target bypass ratio. In this embodiment, the bypass ratio and the power can both change slowly, and this process can maintain water temperature balance.

[0075] The control method of the gas water heater provided by the embodiment of the present invention obtains the outlet water temperature and the current water flow 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; determines the pre-increase power based on the outlet water temperature, the target water temperature and the current water flow of the heat exchange tube; controls the gas water heater to increase the target duration of the pre-increase power operation at a first preset rate 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 decrease to the first power at a first preset rate. 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, makes up for the energy vacancy caused by the increase of the bypass ratio, and provides backup energy for the next water boiling. At the same time, by determining the target duration and the first preset rate, controls the duration and sequence of increasing the pre-increase power, reducing the pre-increase power and increasing the bypass ratio, as well as the adjustment speed of increasing the pre-increase power and reducing the pre-increase power, and can also avoid water temperature fluctuations caused by increasing the bypass ratio, increasing the pre-increase power and reducing the pre-increase power.

[0076] 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 time by the water flow rate, and can increase the bypass ratio when the hot water after the pre-increase power flows to the mixing point to prevent the hot water after the pre-increase power from being too hot and causing water temperature fluctuations. At the same time, since the pre-increase power is increased at a first preset rate, when it flows to the mixing point, the water temperature is constantly rising. At this time, since the bypass ratio needs a certain time to adjust to the target bypass ratio, the adjustment rates of the two correspond, resulting in stable outlet water temperature. At the same time, due to the adjustment of the bypass ratio, the water flow rate of the water in the heat exchange tube will be reduced. By canceling the pre-increase power and reducing it at the first preset rate, the stability of the water temperature of the heat exchange tube before and after reducing the pre-increase power can be guaranteed. If energy is stored by simply increasing the pre-increase power or increasing the bypass ratio, it will bring inevitable fluctuations to the outlet water temperature. And because the bypass ratio is 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 the pre-increase power is canceled for combustion, the water temperature in the heat exchange tube is higher than the water temperature before the pre-increase power is increased, so that the energy of the heat exchange tube can continue to be stored, providing energy for the next time the water is boiled, and management and regulation can be carried out.

[0077] See also Figures 7 to 10 Energy state diagram, Figure 7 It shows the water temperature distribution before increasing the bypass ratio, and the shadow is the basic energy state. Figure 8 The water outlet pipe (high temperature section) shows the heating power increase process, where the shaded part different from the basic energy represents the pre-increase energy state. Figures 7 and 8 Indicates the power increase process, during which the power change is the pre-increase power. Figures 9 and 10It indicates the process that the bypass ratio starts to increase while the power decreases. The shaded part different from the basic energy indicates the pre-increase energy state. It can be seen that both the bypass ratio and the power change gradually. This process can prevent the energy gap from being caused by the increase of the bypass ratio. Fig.11 It is a schematic diagram of the relationship between power and tube length. It can be seen that before the bypass ratio increases, the process of increasing the pre-increase power increases slowly. Starting from the mixing point, the heating power gradually decreases. The shaded part represents the total pre-increase energy.

[0078] In one embodiment, the first preset rate is obtained according to the first bypass ratio, the target bypass ratio and the pre-boost power.

[0079] The pre-increase power represents the amount of change in power. The adjustment time of the bypass ratio can be determined according to the set first bypass ratio and the target bypass ratio. The adjustment time of the bypass ratio is consistent with the power change time, thereby obtaining the first preset rate.

[0080] Further, the following steps are included:

[0081] Step S201, determining a bypass ratio adjustment duration based on a target bypass ratio, a first bypass ratio and a second preset rate.

[0082] Step S202: obtaining a first preset rate based on a ratio of the pre-boost power to the bypass ratio adjustment time.

[0083] The bypass ratio adjustment component provided in the gas water heater for executing the control method of the gas water heater of the present invention is a water proportional valve, and the adjustment speed of the bypass ratio can be controlled by adjusting the water proportional valve. The second preset rate is the adjustment rate of the bypass ratio increasing from the first bypass ratio to the target bypass ratio, and the second preset rate can be set in advance by the water proportional valve. The change of the bypass ratio can be determined according to the target bypass ratio and the first bypass ratio, and the bypass ratio adjustment duration can be obtained by calculating the ratio of the change of the bypass ratio and the second preset rate. The first preset rate can be obtained by calculating the ratio of the pre-increase power and the bypass ratio adjustment duration. The method of determining the first preset rate in this way can ensure that the time for the power to be reduced to the first power is consistent with the time for the bypass ratio to be increased, thereby maintaining the outlet water temperature of the outlet pipe constant.

[0084] In one embodiment, determining the target duration based on the current water flow in step S101 in the above embodiment includes the following steps:

[0085] Step S301, obtaining the volume of the water outlet pipe and the preset duration.

[0086] The preset duration is used to characterize the duration of increasing the pre-increase power. It takes a certain amount of time to control the heat exchange tube to increase the pre-increase power, and this part of the time is the preset duration. 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.

[0087] The duration for which the heat exchange tube increases the pre-increase power can be determined based on actual pre-increase power calculation, or the correspondence between the pre-increase power and the preset duration can be pre-calculated through experiments and stored. The corresponding preset duration can be directly determined based on the actual pre-increase power.

[0088] Step S302, obtaining a first duration based on a ratio of the outlet pipe volume to the current water flow rate.

[0089] Step S303, calculating the sum of the first duration and the preset duration to obtain the target duration.

[0090] The first duration is used to characterize the time it takes for the water to flow from the outlet of the heat exchange tube to the mixing point, and the outlet pipe is used to characterize the water pipe from the outlet of the heat exchange tube to the mixing point. For example, if the length of the outlet pipe in the high temperature section is L1, the radius is R1, and the current water flow rate is v, the first duration = (L1*π*R1 2 ) / v. The target duration is the sum of the first duration and the preset duration.

[0091] In one embodiment, step S102 in the above embodiment includes the following steps:

[0092] Step S401, obtaining a first temperature difference based on the outlet water temperature of the heat exchange tube and the target water temperature.

[0093] 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.

[0094] Step S402, 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.

[0095] Further, step S402 includes the following steps:

[0096] Step S4021, 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.

[0097] Step S4022: 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.

[0098] 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, pre-increase energy = L0*π*R0 2*(Th-Tc) / 2+L1*π*R1 2 *(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.

[0099] Step S403: obtaining the pre-increase power based on a ratio of the pre-increase energy to the first duration.

[0100] Specifically, the first duration = (L1*π*R1 2 ) / v, according to the pre-increase energy in the above steps, the pre-increase power can be obtained = (L0*π*R0 2 *(Th-Tc) / 2+L1*π*R1 2 *(Th-Tc)) / (L1*π*R1 2 / v).

[0101] In one embodiment, in step S101 in the above embodiment, obtaining the outlet water temperature of the heat exchange tube includes:

[0102] The inlet and outlet water temperature difference is determined based on the outlet water temperature and the inlet water temperature, and 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, the outlet water temperature of the heat exchange tube is determined based on the heat exchanger temperature sensor.

[0103] 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:

[0104] P = 1-(Tc-Tj) / (Th-Tj)

[0105] 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.

[0106] 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.

[0107] 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.

[0108] In one embodiment, the control method of the gas water heater in the above embodiment further includes the following steps:

[0109] Step S501, obtaining a target bypass ratio.

[0110] 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.

[0111] Step S502, determining a target water temperature based on a target bypass ratio, an outlet water temperature of a heat exchange tube, and an inlet water temperature.

[0112] 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.

[0113] 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:

[0114] P = 1-(Tc-Tj) / (Th-Tj)

[0115] 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.

[0116] 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 (i.e. the outlet water temperature) can be calculated according to the above corresponding relationship. The inlet water temperature can be measured by an inlet water temperature sensor provided at the inlet end of the inlet pipe.

[0117] 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.

[0118] The present embodiment provides a control device for a gas water heater, comprising: a duration determination module, used to obtain the outlet water temperature of the heat exchange tube and the current water flow rate when the gas water heater is ignited and 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 to control the gas water heater to increase the pre-increase power at a first preset rate on the basis of a first power for the target duration; a bypass ratio adjustment module, used to control the first bypass ratio to increase to the target bypass ratio when the duration from the start of controlling the gas water heater to increase the pre-increase power at a first preset rate on the basis of the first power reaches the target duration, and control the gas water heater to decrease to the first power at a first preset rate.

[0119] An embodiment of the present invention also provides a gas water heater having the above-mentioned control device of the gas water heater, and 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).

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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, characterized in that: 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; 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; Controlling the gas water heater to increase the pre-increase power at a first preset rate based on the first power; When the time duration from starting to control the gas water heater to increase the pre-increase power at a first preset rate on the basis of the first power reaches the target time duration, the first bypass ratio is controlled to increase to the target bypass ratio, and the gas water heater is controlled to decrease to the first power at a first preset rate.

2. The method according to claim 1, characterized in that The first preset rate is obtained according to the first bypass ratio, the target bypass ratio and the pre-boost power.

3. The method according to claim 2, characterized in that The first preset rate is obtained according to the first bypass ratio, the target bypass ratio and the pre-increase power, and includes: Determining a bypass ratio adjustment duration based on the target bypass ratio, the first bypass ratio, and a second preset rate; A first preset rate is obtained based on a ratio of the pre-increase power to the bypass ratio adjustment time.

4. The method according to claim 1, characterized in that: The step of determining the target duration based on the current water flow rate includes: 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; 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; The sum of the first duration and the preset duration is calculated to obtain the target duration.

5. The method according to claim 4, characterized in that The determining of 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: Obtaining a first temperature difference based on the outlet water temperature of the heat exchange tube and the target water temperature; 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; The pre-increase power is obtained based on a ratio of the pre-increase energy to the first duration.

6. The method according to claim 5, characterized in that The obtaining of 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 comprises: 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; 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.

7. 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.

8. 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.

9. A gas water heater, characterized in that: A control method for executing a gas water heater according to any one of claims 1 to 9, comprising: A heat exchanger, wherein 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 pipe, wherein the bypass pipe is respectively connected to the water inlet pipe and the water outlet pipe; a bypass ratio adjusting component, wherein the bypass ratio adjusting component is arranged on the bypass pipe; and a water flow sensor, wherein the water flow sensor is arranged at the water inlet end of the water inlet end.

10. The gas water heater according to claim 9, characterized in that: The bypass ratio adjusting component is a water proportional valve.

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