Control method of water heater and water heater

Abstract

The invention relates to the technical field of water heater constant temperature control, and discloses a water heater control method and a water heater. The method comprises the steps that based on a user water closing signal, accumulated water closing time is recorded; according to the accumulated water closing time, the current bypass ratio is reduced; based on the secondary water boiling signal of the user, recording accumulated water boiling time; and adjusting the current bypass ratio according to the accumulated water boiling time. Therefore, after the user turns off the water, the current bypass ratio is gradually reduced in time, so that more hot water can be obtained from the water storage cavity when the user performs secondary water boiling, and the water outlet temperature during the secondary water boiling of the user is easier to reach the temperature set by the user; the problem that the water outlet temperature is reduced due to the fact that the water temperature in the water storage cavity is reduced but the bypass ratio is not changed in the process that the accumulated water closing time is prolonged is effectively solved, and the rapid constant temperature function of the water heater is achieved by adjusting the bypass ratio in time.

Description

Technical Field

[0001] The invention relates to the technical field of constant temperature control of water heaters, and in particular to a control method of a water heater and a water heater. Background Art

[0002] Gas water heater control technology has become increasingly advanced and intelligent, but there are still some recognized difficulties. For example, when the user stops using water and turns on the water again within a certain period of time, the residual heat of the heat exchanger continues to heat the hot water in the heat exchanger, resulting in a period of overheated high-temperature water. This phenomenon is usually called water stop temperature rise. Furthermore, when igniting and heating again, since it takes a certain amount of time to ignite and heat up, there is a problem that the cold water in the water inlet pipe is not heated in time when passing through the heat exchanger, causing part of the cold water to flow to the outlet. This phenomenon is also called secondary water temperature drop. The root cause of these two problems is the inherent problems caused by the structure of the water heater.

[0003] In the related art, there is a technical solution in which a water outlet pipe of a gas water heater is provided with a water storage chamber of a certain volume or a technical solution in which a bypass pipe is provided between a water inlet pipe and a water outlet pipe of the gas water heater.

[0004] First, in the technical solution with a water storage chamber, when the water is boiled for the second time, since the water storage chamber has stored a certain amount of hot water when the water is boiled for the last time, the overheated high-temperature water in the heat exchanger or the cold water that is not heated in time will mix with the previously stored hot water when passing through the water storage chamber, and finally reduce the water temperature fluctuation to a certain extent. However, when the overheated high-temperature water mixes with the hot water in the water storage chamber, the water temperature of the water storage chamber will still increase, and when the cold water mixes with the hot water in the water storage chamber, the water temperature of the water storage chamber will also decrease. In other words, although this technical solution can reduce the amplitude of the water temperature fluctuation when the water is boiled for the second time, there is still a certain degree of water temperature fluctuation.

[0005] Secondly, the technical solution with a bypass pipe will raise the bypass pipe when the secondary water is started, increase the mixing ratio of cold water and overheated high-temperature water to obtain water of suitable temperature, reduce the bypass ratio when the temperature drops, reduce the mixing ratio of cold water and unheated cold water to obtain water of suitable temperature, and finally reduce the water temperature fluctuation to a certain extent. However, there will still be a situation where cold water and unheated cold water are mixed, that is, this technical solution also has certain defects.

[0006] Therefore, how to further reduce the water temperature fluctuation during the second boiling water becomes a technical problem that needs to be solved urgently. Summary of the invention

[0007] In view of this, the present invention provides a control method for a water heater and a water heater to solve the defects in the related art, that is, how to further reduce the problem of water temperature fluctuation during secondary boiling of water.

[0008] In a first aspect, the present invention provides a control method for a water heater, wherein a bypass pipe is provided between a water inlet pipe and a water outlet pipe of the water heater, and a water storage chamber is provided between a connection between the bypass pipe and the water inlet pipe and a heat exchanger, the method comprising:

[0009] Based on the user's water-off signal, record the cumulative water-off time;

[0010] According to the accumulated water shut-off time, reduce the current bypass ratio;

[0011] Based on the user's secondary water-opening signal, record the cumulative water-opening time;

[0012] Adjust the current bypass ratio according to the accumulated water boiling time.

[0013] The control method of the water heater of the present invention records the cumulative water shut-off time based on the user's water shut-off signal, reduces the current bypass ratio according to the cumulative water shut-off time, and records the cumulative water boiling time based on the user's secondary water boiling signal, so as to adjust the current bypass ratio according to the cumulative water boiling time. Therefore, the structural characteristics of the water storage chamber and the bypass pipe are fully considered and the two are combined. When the water is boiled for the second time, the bypass ratio is adjusted according to the cumulative water boiling time, and the ratio of the hot water mixed once in the mixing chamber and the cold water in the bypass pipe for the second mixing can be accurately adjusted, thereby further reducing the water temperature fluctuation during the secondary water boiling.

[0014] Furthermore, when the water is turned off, the phenomenon of water temperature drop in the water storage chamber caused by the heat dissipation problem in the water storage chamber over time is taken into consideration, so as to effectively ensure that the water in the water storage chamber and the water mixed in the bypass pipe can quickly reach the user set temperature when the water is turned on again. After the user turns off the water, the current bypass ratio is timely reduced, so that when the user turns on the water for the second time, the proportion of hot water obtained from the water storage chamber increases, and the proportion of cold water obtained from the bypass pipe decreases, so that the outlet water temperature when the user turns on the water for the second time can more easily reach the user set temperature, effectively avoiding the problem of lower water outlet temperature caused by the bypass ratio remaining unchanged while the water temperature in the water storage chamber decreases as the cumulative water shut-off time increases, and the rapid constant temperature function of the water heater is achieved by timely adjustment of the bypass ratio.

[0015] In an optional implementation, reducing the current bypass ratio according to the accumulated water shut-off time includes:

[0016] Based on the accumulated water shut-off time, the current bypass ratio is controlled to decrease to a first set bypass ratio according to a preset change rate.

[0017] The control method of the water heater of the present invention controls the current bypass ratio to be reduced to a first set bypass ratio according to a preset rate of change based on the accumulated water shut-off time, thereby gradually reducing the water flow directly from the water inlet pipe to the water outlet after the user turns off the water and before the water is turned on for the second time, and gradually increasing the water flow from the water storage chamber to the water outlet, taking into full consideration the problem of the gradual decrease in the water temperature of the water storage chamber due to the heat dissipation of the water storage chamber after the user turns off the water, effectively avoiding the problem of a sudden change in water temperature caused by a sudden change in the bypass ratio when the water temperature of the water storage chamber drops, and significantly improving the user experience.

[0018] In an optional implementation, adjusting the current bypass ratio according to the accumulated water boiling time includes:

[0019] Before the accumulated water boiling time reaches the first set time, the current bypass ratio is kept unchanged.

[0020] According to the control method of the water heater of the present invention, before the cumulative boiling water time reaches the first set time, the hot water in the water storage chamber can make the water outlet temperature reach the user-set temperature based on the current bypass ratio. At this time, the current bypass ratio can be kept unchanged, and the thermal energy of the water storage chamber can be fully utilized to realize the constant temperature function of the water heater.

[0021] In an optional implementation, adjusting the current bypass ratio according to the accumulated water boiling time further includes:

[0022] When the accumulated water boiling time reaches the second set time, the current bypass ratio is adjusted to the second set bypass ratio;

[0023] wherein the second set bypass ratio is greater than the first set bypass ratio;

[0024] The second set time is greater than the first set time.

[0025] The control method of the water heater of the present invention adjusts the current bypass ratio to the second set bypass ratio when the cumulative boiling water time reaches the second set time, in order to avoid the problem of sudden increase in the outlet water temperature caused by the temperature rise of the water heater when the water is stopped, and the second set bypass ratio is greater than the first set bypass ratio, thereby increasing the amount of cold water directly flowing to the water outlet, effectively avoiding the problem of water temperature increase caused by the temperature rise of the water heater when the water is stopped, and significantly improving the user experience.

[0026] In an optional implementation manner, adjusting the current bypass ratio to a second set bypass ratio includes:

[0027] From the time when the accumulated water boiling time reaches the first set time to the time when the accumulated water boiling time reaches the second set time, the current bypass ratio is increased from the current bypass ratio to the second set bypass ratio according to the first fixed change rate.

[0028] The control method of the water heater of the present invention fully considers the hot water usage of the water storage chamber from the time when the cumulative boiling water time reaches the first set time to the time when the cumulative boiling water time reaches the second set time, and increases the current bypass ratio from the current bypass ratio to the second set bypass ratio according to the first fixed change rate, thereby effectively ensuring the uniform adjustment of the bypass ratio and avoiding sudden changes in the water outlet temperature caused by sudden changes in the bypass ratio.

[0029] In an optional implementation, adjusting the current bypass ratio according to the accumulated water boiling time further includes:

[0030] When the accumulated water boiling time reaches a third set time, the current bypass ratio is adjusted to a third set bypass ratio;

[0031] wherein the third set bypass ratio is less than the second set bypass ratio;

[0032] The third set time is greater than the second set time.

[0033] In an optional implementation manner, adjusting the current bypass ratio to a third set bypass ratio includes:

[0034] From the time when the accumulated water boiling time reaches the second set time until the accumulated water boiling time reaches the third set time, the current bypass ratio is reduced from the second set bypass ratio to the third set bypass ratio according to the second fixed change rate.

[0035] In an optional implementation, adjusting the current bypass ratio according to the accumulated water boiling time further includes:

[0036] When the accumulated water boiling time reaches a fourth set time, the current bypass ratio is adjusted to a target stable bypass ratio;

[0037] The fourth set time is greater than the third set time.

[0038] In an optional implementation manner, adjusting the current bypass ratio to a target stable bypass ratio includes:

[0039] From the time when the accumulated water boiling time reaches the third set time until the accumulated water boiling time reaches the fourth set time, the current bypass ratio is adjusted from the third set bypass ratio to the target stable bypass ratio according to the third fixed change rate.

[0040] The control method of the water heater of the present invention can determine that the water heater is successfully ignited when the cumulative water boiling time reaches the third set time. At this time, the water temperature of the heat exchanger of the water heater begins to rise, so that when the cumulative water boiling time reaches the third set time, the current bypass ratio is adjusted to the third set bypass ratio, and the third set bypass ratio is less than the second set bypass ratio, thereby increasing the proportion of cold water flowing directly from the water inlet pipe to the water outlet. And from the time when the cumulative water boiling time reaches the third set time to the time when the cumulative water boiling time reaches the fourth set time, the current bypass ratio is adjusted from the third set bypass ratio to the target stable bypass ratio according to the third fixed change rate, effectively ensuring the stability of the outlet water temperature and significantly improving the user experience.

[0041] In a second aspect, the present invention provides a water heater, comprising:

[0042] The water storage chamber is arranged before the mixing node of the bypass water mixing branch of the water heater;

[0043] A controller, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, the processor executing the control method of the water heater of the first aspect or any corresponding embodiment thereof by executing the computer instructions, so as to adjust the current bypass ratio of the water heater;

[0044] The current bypass ratio is used to characterize the ratio of the cold water directly transmitted to the mixing node but not flowing through the water storage chamber to the total flow rate flowing through the water heater. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] 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.

[0046] Figure 1 A schematic diagram showing the water supply principle of a water heater in the related art is shown;

[0047] Figure 2 A schematic diagram of a water supply principle of a water heater showing a method for controlling a water heater according to an embodiment of the present invention;

[0048] Figure 3 Another schematic diagram of water supply principle of a water heater showing a control method of a water heater according to an embodiment of the present invention;

[0049] Figure 4 is a flow chart of a method for controlling a water heater according to an embodiment of the present invention;

[0050] Figure 5is a flow chart of another water heater control method according to an embodiment of the present invention;

[0051] Figure 6 is a flowchart of a specific application example of a control method for a water heater according to an embodiment of the present invention;

[0052] Figure 7 is a schematic diagram of a bypass ratio variation curve of a water heater after adopting the control method of the water heater according to an embodiment of the present invention;

[0053] Figure 8 is a comparison diagram of a water tank water temperature variation curve of a water storage chamber after adopting the control method of a water heater according to an embodiment of the present invention and a water outlet water temperature variation curve of a water heater without adopting the control method of a water heater according to an embodiment of the present invention;

[0054] Fig. 9 is a schematic diagram of temperature analysis of the straight tube and water storage chamber inside the heat exchanger of the water heater according to an embodiment of the present invention;

[0055] Fig.10 is a schematic diagram of a structural block diagram of a water heater according to an embodiment of the present invention;

[0056] Fig.11 is a schematic diagram of the hardware structure of a controller of a water heater according to an embodiment of the present invention;

[0057] 101 heat exchanger; 102 main controller; 103 electric control diverter valve;

[0058] 104 water flow sensor; 105 water pump; 106 one-way valve;

[0059] 107 cold water pipe; 108 water storage chamber; 109 water use device;

[0060] J1 water inlet temperature detection point; J2 water tank water temperature detection point; J3 water outlet temperature detection point;

[0061] LJ cold water inlet; RC hot water outlet. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0063] In order to better illustrate the control method of the water heater and the water heater provided by the present invention, an application scenario of the control method of the water heater in the embodiment of the present invention is first exemplarily illustrated here. Figure 1 The schematic diagram of the water supply principle of the water heater in the related art is shown as follows: Figure 1 As shown, the water heater includes a burner (not shown in the figure), a main controller 102 and a hot water exchanger, a cold water inlet LJ, a water pump 105, a water flow sensor 104, a water inlet temperature detection point J1 and an electrically controlled diverter valve 103 are sequentially arranged on the cold water pipe 107 along the water flow direction, a water tank temperature detection point is arranged at the water outlet of the heat exchanger 101, and an outlet water temperature detection point J3 is arranged at a position close to the hot water outlet RC. Part of the cold water can be bypassed to the hot water outlet RC through a water pipe CD connected to the second outlet C of the electrically controlled diverter valve 103. An outlet water temperature detection point J3 is arranged between the node D and the hot water outlet RC. A one-way valve 106 is arranged between the cold water pipe 107 and the hot water pipe of the terminal water use device 109, and the one-way valve 106 is used to realize an external circulation with a zero cold water function.

[0064] When the user turns on the water for the second time after turning off the water, by quickly adjusting the bypass ratio of the electrically controlled diverter valve 103, the ratio of cold water to hot water can be adjusted immediately. In the case of water outage temperature rise, the bypass ratio is increased, and the proportion of cold water directly flowing out through the CD tube is increased, effectively avoiding the excessively high outlet water temperature caused by water outage temperature rise. In the case of a temperature drop after a long water outage, the hot water stored in the heat exchanger 101, which is higher than the normal water temperature, is used to reduce the bypass ratio, thereby increasing the proportion of hot water flowing out of the heat exchanger 101 and avoiding the outlet water temperature drop. This avoids the problems of water outage temperature rise and water outage temperature drop. However, this solution is limited by the water storage capacity and water temperature of the heat exchanger 101. When the water temperature inside the heat exchanger 101 is low, it is impossible to achieve rapid constant temperature.

[0065] In this regard, the water heater used in the control method of the water heater of the embodiment of the present invention has an energy storage water tank ( Figure 2 and Figure 3 The energy storage water tank has a water storage chamber 108. The specific position of the water storage chamber 108 can be referred to Figure 2 and Figure 3 .

[0066] Figure 2 A schematic diagram of a water supply principle of a water heater showing a control method of a water heater according to an embodiment of the present invention, Figure 3 Another schematic diagram of water supply principle of a water heater is shown in the control method of a water heater according to an embodiment of the present invention. Figure 2 and Figure 3The difference between the schematic diagram of the water supply principle of the water heater in FIG. 1 is that the position of the electric control diverter valve 103 is slightly different, but whether the electric control diverter valve 103 is set as Figure 2 The position shown is still Figure 3 At the position shown, the water supply principle of the control method of the water heater in the embodiment of the present invention is the same.

[0067] like Figure 2 and Figure 3 As shown, the water heater is a zero cold water gas water heater, which has a burner (not shown in the figure), a heat exchanger 101, a water pump 105, a water flow sensor 104, etc. The water pump 105, the water flow sensor 104, and the water inlet temperature detection point J1 are arranged in sequence after the cold water inlet LJ along the water flow direction on the cold water pipe 107. Before the water in the cold water pipe 107 is connected to the heat exchanger 101, an electric-controlled diverter valve 103 is arranged. The electric-controlled diverter valve 103 includes a valve inlet A, a first outlet B, and a second outlet C. The first outlet B is connected to the heat exchanger 101, and the second outlet C is connected to the outlet pipe of the heat exchanger 101 and connected to the D node. A water tank temperature detection point and a water storage chamber 108 are arranged between the node D and the heat exchanger 101. An outlet water temperature detection point J3 is arranged between the node D and the hot water outlet RC. A one-way valve 106 is provided between the cold water pipe 107 and the hot water pipe of the terminal water-using device 109 , and the one-way valve 106 is used to realize external circulation with zero cold water function.

[0068] It should be noted that the above Figure 2 and Figure 3 This is an exemplary description of the water supply principle of the water heater control method of the embodiment of the present invention. In actual application, the positions of the components such as the electric control diverter valve and the water storage chamber can be adjusted according to actual needs. For example, the water storage chamber can be as follows: Figure 2 and Figure 3 The arrangement shown is before the node D of the water heater, and may also be arranged directly at the location where the node D is located.

[0069] According to an embodiment of the present invention, a control method embodiment of a water heater is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0070] In this embodiment, a control method for a water heater is provided, which can be used for the above water heater. Figure 4 is a flow chart of a method for controlling a water heater according to an embodiment of the present invention. Figure 4 As shown, the process includes the following steps:

[0071] Step S401, based on the user's water-off signal, record the accumulated water-off time.

[0072] In an optional embodiment of the present invention, the user water shut-off signal may be a signal of the user turning off the water device switch, or may be a current water flow signal lower than the water shut-off flow rate sent by the water flow sensor 104. When the main controller of the water heater receives the user water shut-off signal, it may start recording the accumulated water shut-off time.

[0073] Step S402, reducing the current bypass ratio according to the accumulated water shut-off time.

[0074] In an optional embodiment, a preset bypass ratio is set inside the water heater, and the bypass ratio is the ratio of the water flow through CD to the total flow through the water heater, wherein the current bypass ratio S can be calculated using the following formula (1):

[0075] S=(T2-Ts) / (T2-T1) (1)

[0076] Wherein, S represents the current bypass ratio;

[0077] T2 represents the water tank temperature collected by the water tank temperature detection point J2;

[0078] Ts represents the user-set temperature;

[0079] T1 represents the inlet water temperature collected by the inlet water temperature detection point J1.

[0080] The current bypass ratio may be used to represent the ratio of the cold water directly transmitted from the cold water pipe to the node D but not flowing through the water storage chamber to the total water flow flowing through the node D.

[0081] In an optional embodiment, in order to have enough energy for bypass regulation when the water is boiled for the second time, the bypass ratio will be adjusted to the target stable bypass ratio when the water heater is in steady-state combustion, and the water tank temperature T2 will be increased as much as possible. Relative to a certain moment, the larger the bypass ratio, the larger the value of the water temperature T2 in the heat exchanger, and the more hot water can be used in the heat exchanger and the water storage chamber. It should be noted here that the water storage chamber can also store hot water with very high temperature, but when the temperature of the hot water stored in the heat exchanger and the water storage chamber exceeds the limit temperature, scale is easily generated, so T2 here is preferably the limit temperature, which is related to the material of the heat exchanger and the water storage chamber. It can be understood that the limit temperature can be measured experimentally, such as 60°C. Therefore, when the water is turned off in the case of steady-state combustion of the water heater, the bypass ratio will be reduced from the target stable bypass ratio.

[0082] Specifically, after the user turns off the water this time, the hot water in the water storage chamber will gradually decrease as the water storage chamber dissipates heat. In order to ensure that when the user turns on the water for the second time, the bypass cold water can continue to maintain the outlet water temperature at the temperature set by the user, the bypass ratio needs to be reduced in advance. The reduction method can be linear reduction according to a preset change rate, or the bypass ratio can be reduced in a step-by-step manner by reducing it for a certain period of time.

[0083] In an optional implementation, the current bypass ratio may be controlled to decrease to a first set bypass ratio according to a preset change rate based on the accumulated water shut-off time.

[0084] Specifically, after the user turns off the water this time, the hot water in the water storage chamber will gradually decrease as the water storage chamber dissipates heat. In order to ensure that when the user turns on the water for the second time, the bypassed cold water can continue to maintain the outlet water temperature at the temperature set by the user, the current bypass ratio can be controlled to decrease to the first set bypass ratio according to the preset change rate, and the preset change rate can be set according to actual needs. The preset change rate can be an empirical value obtained from experiments, such as reducing the bypass ratio by 3% every 10 seconds.

[0085] The control method of the water heater of the present invention controls the current bypass ratio to be reduced to a first set bypass ratio according to a preset rate of change based on the accumulated water shut-off time, thereby gradually reducing the water flow directly from the water inlet pipe to the water outlet after the user turns off the water and before the water is turned on for the second time, and gradually increasing the water flow from the water storage chamber to the water outlet, taking into full consideration the problem of the gradual decrease in the water temperature of the water storage chamber due to the heat dissipation of the water storage chamber after the user turns off the water, effectively avoiding the problem of a sudden change in water temperature caused by a sudden change in the bypass ratio when the water temperature of the water storage chamber drops, and significantly improving the user experience.

[0086] Step S403, based on the user's second water-on signal, record the accumulated water-on time.

[0087] In an optional embodiment of the present invention, in order to fully consider the influence of factors such as the hot water usage of the water storage chamber and the water stop temperature rise of the water heater on the water outlet temperature, the current bypass ratio of the water heater is further adjusted based on the time change. Therefore, here, based on the user's secondary water-opening signal, the cumulative water-opening time is recorded. The user's secondary water-opening signal can be a signal of the switch of the user terminal's water-using device being turned on within a certain period of time after the water is turned off, or it can be a current water flow signal higher than the water flow of boiling water emitted by the water flow sensor 104 within a certain period of time after the water is turned off. The main controller of the water heater can detect the user's secondary water-opening signal by communicating with the switch of the water-using device.

[0088] Step S404, adjusting the current bypass ratio according to the accumulated water boiling time.

[0089] In an optional embodiment of the present invention, the hot water in the water storage chamber can be fully utilized, and the current bypass ratio is kept unchanged before the cumulative first set time is reached. It is also possible to fully consider the water stop temperature rise after the water heater is started, and gradually increase the current bypass ratio to the second set bypass ratio. It is also possible to fully consider the end of the water stop temperature rise phenomenon of the water heater, and the stabilization of the water tank temperature at the water outlet of the heat exchanger of the water heater. After the cumulative boiling time reaches the second set time, the current bypass ratio begins to be gradually reduced, and when the cumulative boiling time reaches the third set time, the current bypass ratio is adjusted to the third set bypass ratio. In practical applications, the first set time, the second set time, the third set time, the first set bypass ratio, the second set bypass ratio, and the third set bypass ratio can also be set according to the characteristics and actual needs of different water heaters. It is also possible to set different adjustment methods to adjust the current bypass ratio based on the cumulative boiling time according to the characteristics of the water heater and the actual needs of the user.

[0090] The control method of the water heater of the present invention records the cumulative water shut-off time based on the user's water shut-off signal, reduces the current bypass ratio according to the cumulative water shut-off time, and records the cumulative water boiling time based on the user's second water-on signal, so as to adjust the current bypass ratio according to the cumulative water boiling time. Thus, the phenomenon of water temperature drop in the water storage chamber caused by the heat dissipation problem of the water storage chamber over time is fully considered, and it is effectively guaranteed that the water in the water storage chamber and the water mixed with the bypass pipe can quickly reach the user set temperature when the water is turned on again. After the user turns off the water, the current bypass ratio is timely reduced, so that when the user turns on the water for the second time, the proportion of hot water obtained from the water storage chamber increases, and the proportion of cold water obtained from the bypass pipe decreases, so that the outlet water temperature when the user turns on the water for the second time is easier to reach the user set temperature, effectively avoiding the problem of the outlet water temperature drop caused by the water temperature in the water storage chamber decreasing as the cumulative water shut-off time becomes longer but the bypass ratio remains unchanged, and the rapid constant temperature function of the water heater is realized by timely adjusting the bypass ratio.

[0091] In this embodiment, a control method for a water heater is provided, which can be used for the above water heater. Figure 5 is a flow chart of a method for controlling a water heater according to an embodiment of the present invention. Figure 5 As shown, the process includes the following steps:

[0092] Step S501, based on the user's water-off signal, record the accumulated water-off time.

[0093] For details, please see Figure 4 Step S401 of the illustrated embodiment will not be described in detail here.

[0094] Step S502, reducing the current bypass ratio according to the accumulated water shut-off time.

[0095] For details, please see Figure 4 Step S402 of the illustrated embodiment will not be described in detail here.

[0096] Step S503, based on the user's second water-on signal, record the accumulated water-on time.

[0097] For details, please see Figure 4 Step S403 of the illustrated embodiment will not be described in detail here.

[0098] Step S504, adjusting the current bypass ratio according to the accumulated water boiling time.

[0099] Specifically, the above step S504 includes:

[0100] Step S5041, before the accumulated water boiling time reaches the first set time, the current bypass ratio is kept unchanged.

[0101] In some optional embodiments, after the user turned off the water for the last time, the current bypass ratio has been reduced to the first set bypass ratio S1 according to the accumulated water-off time. After the user turns on the water for the second time, before the accumulated water-on time reaches the first set time, since there is hot water in the water storage chamber, the hot water obtained at the water-using device can be maintained at the temperature set by the user, so the first set bypass ratio S1 can be maintained unchanged.

[0102] In addition, there is a situation where the current bypass ratio has not yet been reduced to the first set bypass ratio S1. Usually, as long as the current bypass ratio is greater than the first set bypass ratio S1, the current bypass ratio can be kept unchanged before the cumulative boiling water time reaches the first set time.

[0103] In some optional embodiments, the first set time t1 can be calculated based on the volume of the water storage chamber and the water flow rate after the water heater is turned on again. According to the volume of the water storage chamber divided by the water flow rate after the water heater is turned on again, a time can be obtained, and then a correction compensation processing is performed on this time to obtain the first set time t1. For example, the volume of the water storage chamber is 0.5L, and the water flow rate after the water heater is turned on again is 7L / min, then the first set time t1 = 0.5 / 7*60*80% = 3.4s, where 80% represents a correction compensation coefficient. In addition, the first set time t1 can also be selected based on the actual test data.

[0104] The control method of the water heater of the present invention enables the hot water in the water storage chamber to reach the user-set water outlet temperature based on the current bypass ratio before the cumulative boiling water time reaches the first set time. At this time, the current bypass ratio can be kept unchanged, and the thermal energy of the water storage chamber can be fully utilized to realize the constant temperature function of the water heater.

[0105] Step S5042: When the accumulated water boiling time reaches the second set time, the current bypass ratio is adjusted to the second set bypass ratio.

[0106] The second set bypass ratio is greater than the first set bypass ratio, and the second set time is greater than the first set time.

[0107] For example, after the cumulative boiling time reaches the first set time, the water heater stops the water and the temperature rise phenomenon gradually appears. At this time, by increasing the current bypass ratio, the cold water ratio is increased to neutralize the water stop temperature rise. Specifically, from the first set time to the second set time, the current bypass ratio can be evenly increased from the first set bypass ratio S2 to the second set bypass ratio S3.

[0108] It should be noted that the water heater does not have a problem of temperature rise when the water supply is cut off under some working conditions, and there is no temperature rise phenomenon when the water supply is cut off. For example, when the water heater is running at a small load, the water is turned off and then turned on again. At this time, the water heater will not have a problem of temperature rise when the water supply is cut off, or the temperature rise is not obvious. Then the moment when the cumulative boiling water time reaches the first set time t1 and the moment when it reaches the second set time t2 can be determined as the same moment, and the first set bypass ratio is equal to the second set bypass ratio.

[0109] The control method of the water heater of the present invention adjusts the current bypass ratio to the second set bypass ratio when the cumulative boiling water time reaches the second set time, in order to avoid the problem of sudden increase in the outlet water temperature caused by the temperature rise of the water heater when the water is stopped, and the second set bypass ratio is greater than the first set bypass ratio, thereby increasing the amount of cold water directly flowing to the water outlet, effectively avoiding the problem of water temperature increase caused by the temperature rise of the water heater when the water is stopped, and significantly improving the user experience.

[0110] In some optional implementations, step S5042 includes:

[0111] Step a1, from the time when the accumulated water boiling time reaches the first set time to the time when the accumulated water boiling time reaches the second set time, the current bypass ratio is increased from the current bypass ratio to the second set bypass ratio according to the first fixed change rate.

[0112] Here, the first fixed change rate is mainly to ensure a uniform increase in the current bypass ratio and avoid a sudden change in the outlet water temperature of the water heater caused by a sudden change in the current bypass ratio. The first fixed change rate can be determined based on the first set time, the second set time, the first set bypass ratio and the second set bypass ratio measured in experiments.

[0113] In some optional embodiments, the time between the second set time t2 and the first set time t1 can be calculated based on the volume of the last two straight tubes of the main heat exchanger of the heat exchanger and the water flow rate. For example, the volume of the last two straight tubes of the main heat exchanger of the heat exchanger is 0.06L, and the water flow rate is 7L / min, then t2-t1=0.06 / 7*60*120%=0.6s, where 120% is a compensation coefficient. Further, t2-t1 can also be selected based on actual test data.

[0114] The second set bypass ratio S3 is a series of empirical values ​​obtained based on experimental data. The second set bypass ratio S3 is mainly related to the user set temperature TS and the thermal load of the water heater. For example, the second set bypass ratio S3 can be set to 65°C. When the thermal load is at the maximum thermal load, the second set bypass ratio S3 is 20% larger than the first set bypass ratio S2. Under some operating conditions, because there is no water stop temperature rise, this step S5042 can be directly omitted, that is, t2-t1=0, S3=S2, and the parameters of these different operating conditions can be obtained through experimental tests.

[0115] The control method of the water heater of the present invention fully considers the hot water usage of the water storage chamber from the time when the cumulative boiling water time reaches the first set time to the time when the cumulative boiling water time reaches the second set time, and increases the current bypass ratio from the current bypass ratio to the second set bypass ratio according to the first fixed change rate, thereby effectively ensuring the uniform adjustment of the bypass ratio and avoiding sudden changes in the water outlet temperature caused by sudden changes in the bypass ratio.

[0116] Step S5043, when the accumulated water boiling time reaches the third set time, the current bypass ratio is adjusted to the third set bypass ratio.

[0117] The third set bypass ratio is smaller than the second set bypass ratio, and the third set time is larger than the second set time.

[0118] Specifically, the time difference t3-t2 between the moment t3 when the cumulative water-boiling time reaches the third set time and the moment t2 when the cumulative water-boiling time reaches the second set time can be calculated based on the volume and water flow of the first two straight pipes of the main heat exchanger of the water heater. For example, the volume of the first two straight pipes of the main heat exchanger of the heat exchanger is 0.06L, and the water flow is 7L / min. t3-t2=0.06 / 7*60*0.8%=0.4s, where 80% is a compensation coefficient. In addition, t3-t2 can also be selected based on the actual test data.

[0119] The third set bypass ratio S4 can be selected based on experimental test results. Usually, S4 can be between 50% and 0% of the second set bypass ratio S3. It is related to the user-set temperature and water flow rate. A series of parameters can be obtained through testing and used to call during the control process of the water heater.

[0120] In some optional implementations, step S5043 includes:

[0121] Step b1, from the time when the accumulated water boiling time reaches the second set time to the time when the accumulated water boiling time reaches the third set time, the current bypass ratio is reduced from the second set bypass ratio to the third set bypass ratio according to the second fixed change rate.

[0122] Step S5044, when the accumulated water boiling time reaches a fourth set time, the current bypass ratio is adjusted to a target stable bypass ratio, wherein the fourth set time is greater than the third set time.

[0123] In some optional implementations, step S5044 includes:

[0124] Step c1, from the time when the accumulated water boiling time reaches the third set time to the time when the accumulated water boiling time reaches the fourth set time, the current bypass ratio is adjusted from the third set bypass ratio to the target stable bypass ratio according to the third fixed change rate.

[0125] Specifically, after the cumulative boiling time reaches the third set time t3, the water heater is successfully ignited, the water temperature of the heat exchanger begins to rise, and the current bypass ratio increases uniformly from the cumulative boiling time reaching the third set time to the cumulative boiling time reaching the fourth set time, and is adjusted from the third set bypass ratio S3 to the target stable bypass ratio S4. Thus, the cold water ratio is uniformly increased, and the stable high-temperature water and cold water mixing state is restored, so that the water outlet temperature of the water heater is maintained at the user-set temperature Ts.

[0126] The time from when the cumulative boiling water time reaches the third set time to when the cumulative boiling water time reaches the fourth set time t4-t3 can be set to within 5 seconds according to experience, and the target stable bypass ratio S4 can be obtained according to the latest state of the water heater operation. That is, the above formula (1) is used to obtain the target stable bypass ratio S4 according to the real-time inlet water temperature T1, the water tank temperature T2 and the user-set temperature TS.

[0127] The purpose of adjusting the current bypass ratio from the third set bypass ratio to the target stable bypass ratio according to the third fixed change rate is mainly to avoid sudden changes in the current bypass ratio and ensure uniform changes in the current bypass ratio, thereby effectively ensuring the stability of the outlet water temperature.

[0128] The control method of the water heater of the present invention can determine that the water heater is successfully ignited when the cumulative water boiling time reaches the third set time. At this time, the water temperature of the heat exchanger of the water heater begins to rise, so that when the cumulative water boiling time reaches the third set time, the current bypass ratio is adjusted to the third set bypass ratio, and the third set bypass ratio is less than the second set bypass ratio, thereby increasing the proportion of cold water flowing directly from the water inlet pipe to the water outlet. And from the time when the cumulative water boiling time reaches the third set time to the time when the cumulative water boiling time reaches the fourth set time, the current bypass ratio is adjusted from the third set bypass ratio to the target stable bypass ratio according to the third fixed change rate, effectively ensuring the stability of the outlet water temperature and significantly improving the user experience.

[0129] In this embodiment, a control method for a water heater is provided, which can be used for the above water heater. Figure 6 is a flow chart of a method for controlling a water heater according to an embodiment of the present invention. Figure 6 As shown, the process includes the following steps:

[0130] Step S601, based on the user's water-off signal, record the accumulated water-off time.

[0131] For details, please see Figure 4 Step S401 of the illustrated embodiment will not be described in detail here.

[0132] Step S602, reducing the current bypass ratio according to the accumulated water shut-off time.

[0133] Specifically, Figure 7 FIG. 4 shows a schematic diagram of a bypass ratio variation curve of a water heater after adopting the control method of the water heater according to an embodiment of the present invention. Figure 7 As shown, the moment when the user's water-off signal is received can be recorded as tg, and the bypass ratio at this time can be recorded as S0. S0 can be a bypass ratio preset inside the water heater, which can be calculated and determined by referring to the above formula (1). From this moment to t0, the current bypass ratio can be reduced to a first preset bypass ratio S1 according to a preset change rate. The preset change rate can be an empirical value obtained from experimental tests, such as reducing the bypass ratio by 3% every 10 seconds, and the first preset bypass ratio S1 is determined accordingly.

[0134] like Figure 7 In the bypass ratio variation curve diagram shown, the bypass ratio variation curve is illustrated by taking the time t0 as the same time as the time when the user turns on the water for the second time. In practical applications, the time when the user turns on the water for the second time can be between the time tg and the time t0, or after the time t0.

[0135] For other implementation details, see Figure 4 Step S402 of the illustrated embodiment will not be described in detail here.

[0136] Step S603, based on the user's second water-on signal, record the accumulated water-on time.

[0137] In this embodiment of the present invention, the time when the user's second water-turning signal is received can be recorded as tk, and the timing can be started from this moment.

[0138] For other implementation details, see Figure 4 Step S403 of the illustrated embodiment will not be described in detail here.

[0139] Step S604, adjusting the current bypass ratio according to the accumulated water boiling time.

[0140] Specifically, step S604 may include:

[0141] Step S6041, before the accumulated water boiling time reaches the first set time t1, maintain the current bypass ratio.

[0142] In some optional implementations of the present invention, time tk may be considered as time 0, so time t1 may also be considered as the cumulative boiling water time reaching the first set time t1.

[0143] In practical applications, time tk can be before or after time t0. The current bypass ratio at time tk can be greater than S1 or less than S1. Times t1, t2, t3, and t4 are all accumulated with time tk as time 0.

[0144] Step S6042, after the accumulated water boiling time reaches the first setting time t1 and after the accumulated water boiling time reaches the second setting time t2, the current bypass ratio is adjusted to the second setting bypass ratio S2.

[0145] Step S6043, after the cumulative boiling water time reaches the second set time t2, start to gradually reduce the current bypass ratio, and when the cumulative boiling water time reaches the third set time t3, adjust the current bypass ratio to the third set bypass ratio S3.

[0146] Step S6044: when the accumulated water boiling time reaches the fourth set time t4, the current bypass ratio is adjusted to the target stable bypass ratio S4.

[0147] Figure 8 A comparison diagram of a water tank water temperature variation curve of a water storage chamber after adopting the control method of a water heater according to an embodiment of the present invention and a water outlet water temperature variation curve of a water heater without adopting the control method of a water heater according to an embodiment of the present invention is shown.

[0148] like Figure 8As shown, W1 is used to characterize the phenomenon of water stop temperature rise of the water heater after receiving the second water-boiling signal from the user. W2 is used to characterize the phenomenon of secondary water-boiling temperature drop of the water heater after the water heater is successfully ignited after receiving the second water-boiling signal from the user. W3 is used to characterize the outlet water temperature change curve of an ordinary water heater without bypass cold water and water storage chamber that does not adopt the control method of the water heater of the embodiment of the present invention, after receiving the second water-boiling signal from the user. W4 is used to characterize the change curve of the water tank temperature of the water storage chamber of the water heater that adopts the control method of the water heater of the embodiment of the present invention. W5 is used to characterize the change curve of the outlet water temperature of the water heater that adopts the control method of the water heater of the embodiment of the present invention. According to Figure 8 It can be seen that, compared with a common water heater without bypass cold water and water storage chamber that does not adopt the control method of the water heater of the embodiment of the present invention, the water outlet temperature can be kept basically unchanged by adopting the control method of the water heater of the embodiment of the present invention.

[0149] By using the control method of the water heater of the embodiment of the present invention, the outlet water temperature can be kept basically constant. Fig. 9 The temperature analysis diagram of the straight tube and water storage chamber inside the heat exchanger of the water heater is analyzed. Fig. 9 As shown, if a water storage chamber is added inside the water heater, the hot water in the water storage chamber and the heat exchanger with a temperature higher than the user-set temperature Ts can be fully utilized.

[0150] The present invention also provides a water heater. Fig.10 , Fig.10 is a schematic diagram of the structure of a water heater provided by an optional embodiment of the present invention, such as Fig.10 As shown, the water heater includes:

[0151] The water storage chamber 108 is arranged before the mixing node of the bypass water mixing branch of the water heater;

[0152] The controller 1001 includes: a memory and a processor, 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 water heater of the first aspect or any corresponding embodiment thereof by executing the computer instructions to adjust the current bypass ratio of the water heater;

[0153] The current bypass ratio is used to characterize the ratio of the cold water directly transmitted to the mixing node but not flowing through the water storage chamber to the total flow rate flowing through the water heater.

[0154] The present invention also provides a water heater controller. Fig.11 , Fig.11 is a schematic diagram of the structure of a controller of a water heater provided by an optional embodiment of the present invention, such as Fig.11As shown, the controller of the water heater includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. The various components are connected to each other using different buses for communication, and can be installed on a common motherboard or installed in other ways as needed. The processor can process instructions executed in the controller of the 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 water heater controllers can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Fig.11 A processor 10 is taken as an example.

[0155] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 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.

[0156] The memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiment.

[0157] The memory 20 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 water heater controller, etc. In addition, the memory 20 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 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the water heater controller 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.

[0158] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0159] The controller of the water heater further includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Fig.11 The example of connecting through bus is taken in the following.

[0160] The input device 30 can receive input digital or character information, and generate key signal input related to the user settings and function control of the controller of the water heater, such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator bar, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (e.g., an LED) and a tactile feedback device (e.g., a vibration motor), etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0161] 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.

[0162] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0163] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for controlling a water heater, characterized in that: A bypass pipe is provided between the water inlet pipe and the water outlet pipe of the water heater, and a water storage chamber is provided between the connection between the bypass pipe and the water inlet pipe and the heat exchanger. The method comprises: Based on the user's water-off signal, record the cumulative water-off time; According to the accumulated water shut-off time, reducing the current bypass ratio; Based on the user's secondary water-opening signal, record the cumulative water-opening time; The current bypass ratio is adjusted according to the accumulated water boiling time.

2. The method according to claim 1, characterized in that The reducing the current bypass ratio according to the accumulated water shut-off time includes: Based on the accumulated water shut-off time, the current bypass ratio is controlled to decrease to a first set bypass ratio according to a preset change rate.

3. The method according to claim 1, characterized in that The adjusting the current bypass ratio according to the accumulated water boiling time includes: Before the accumulated water boiling time reaches the first set time, the current bypass ratio is kept unchanged.

4. The method according to claim 3, characterized in that: The adjusting the current bypass ratio according to the accumulated water boiling time also includes: When the accumulated water boiling time reaches a second set time, adjusting the current bypass ratio to a second set bypass ratio; wherein the second set bypass ratio is greater than the first set bypass ratio; The second set time is greater than the first set time.

5. The method according to claim 4, characterized in that The step of adjusting the current bypass ratio to a second set bypass ratio includes: From the time when the accumulated water boiling time reaches the first set time until the accumulated water boiling time reaches the second set time, the current bypass ratio is increased from the current bypass ratio to the second set bypass ratio according to a first fixed change rate.

6. The method according to claim 5, characterized in that The adjusting the current bypass ratio according to the accumulated water boiling time also includes: When the accumulated water boiling time reaches a third set time, adjusting the current bypass ratio to a third set bypass ratio; wherein the third set bypass ratio is smaller than the second set bypass ratio; The third set time is greater than the second set time.

7. The method according to claim 6, characterized in that The step of adjusting the current bypass ratio to a third set bypass ratio includes: From the time when the accumulated water boiling time reaches the second set time until the accumulated water boiling time reaches the third set time, the current bypass ratio is reduced from the second set bypass ratio to the third set bypass ratio according to a second fixed change rate.

8. The method according to claim 6, characterized in that The adjusting the current bypass ratio according to the accumulated water boiling time also includes: When the accumulated water boiling time reaches a fourth set time, adjusting the current bypass ratio to a target stable bypass ratio; The fourth set time is greater than the third set time.

9. The method according to claim 8, characterized in that The adjusting the current bypass ratio to a target stable bypass ratio comprises: From the time when the accumulated water boiling time reaches the third set time until the accumulated water boiling time reaches the fourth set time, the current bypass ratio is adjusted from the third set bypass ratio to the target stable bypass ratio according to a third fixed change rate.

10. A water heater, characterized in that: include: A water storage chamber is arranged before a mixing node of a bypass water mixing branch of the water heater; A controller, comprising: 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 water heater according to any one of claims 1 to 9 by executing the computer instructions to adjust the current bypass ratio of the water heater; The current bypass ratio is used to represent the ratio of the cold water directly transmitted to the mixing node but not flowing through the water storage chamber to the total flow of the water heater.

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