Electric water heater, and controller and control method therefor

Abstract

Disclosed in the present invention are an electric water heater, and a controller and control method therefor. The electric water heater comprises: an inner tank (1), which is used for storing water; a temperature measurement member (2), which is used for measuring the temperature of water in the inner tank (1); and a heating assembly, which is arranged below the temperature measurement member (2), wherein the heating assembly is used for heating the water in the inner tank (1) at a heating stage and maintaining the temperature of the water in the inner tank (1) during a temperature maintaining stage, and the heating assembly comprises upper heating members and lower heating members arranged from top to bottom in the height direction, the distance from the upper heating members to the temperature measurement member (2) being within a preset range. The control method comprises: at a temperature maintaining stage, only turning on at least some lower heating members to maintain the temperature, or making the number of instances the upper heating members maintain the temperature be less than the number of instances the lower heating members maintain the temperature. By means of optimizing a control logic at the temperature maintaining stage, the present application can effectively reduce the overall energy consumption of an electric water heater without increasing costs.

Description

Electric water heater, controller and control method thereof

[0001] Related applications

[0002] The present application claims priority to Chinese Patent Application No. 202411327896.4, filed on September 23, 2024, entitled "Electric water heater, controller and control method thereof". TECHNICAL FIELD

[0003] The present application relates to the technical field of water heater control, in particular to an electric water heater, a controller and a control method thereof. BACKGROUND

[0004] Commercial heating devices can supply hot water and are generally used in scenarios such as hotels, guesthouses, bath centers, hospitals and homes. Most commercial heating devices currently use water storage heating, and a relatively typical commercial heating device is an electric water heater.

[0005] However, the energy consumption of the current commercial electric water heater is generally large and needs to be further improved.

[0006] It should be noted that the above introduction to the technical background is only to facilitate a clear and complete description of the technical solutions of the present application, and to facilitate the understanding of those skilled in the art. The above technical solutions cannot be considered as known to those skilled in the art merely because they are described in the background section of the present application. SUMMARY

[0007] In view of the defects of the prior art, the present application provides an electric water heater, a controller and a control method thereof. By optimizing the control logic of the heat preservation stage, the energy consumption of the electric water heater can be effectively reduced without increasing the cost.

[0008] The specific technical solutions of the present application are as follows:

[0009] A control method of an electric water heater, the electric water heater comprising: an inner container for storing water, a temperature detection member for detecting the water temperature in the inner container, a heating assembly arranged below the temperature detection member, the heating assembly being used for heating the water in the inner container in a heating stage and for heat preserving the water in the inner container in a heat preservation stage, the heating assembly comprising an upper heating member and a lower heating member arranged from top to bottom along a height direction, the distance from the upper heating member to the temperature detection member being within a preset distance, the control method comprising: in the heat preservation stage, only starting at least part of the lower heating member to perform heat preservation or the number of times of heat preservation of the upper heating member is less than the number of times of heat preservation of the lower heating member.

[0010] A controller configured to perform the control method of the electric water heater as claimed in any one of the preceding claims.

[0011] An electric water heater comprising the controller as claimed in the preceding claim.

[0012] The technical solution of the present application has the following remarkable beneficial effects:

[0013] In the embodiments of the present application, the control logic of the electric water heater in the heat preservation stage is optimized. When the electric water heater enters the heat preservation stage, the number of times that the upper heating element is allowed to perform heat preservation is less than the number of times that the lower heating element is allowed to perform heat preservation, or only at least part of the lower heating element is allowed to perform heat preservation. As a result, the upper heating element with a large heat conversion yield difference is allowed to reduce the number of start-ups, or even not to start up, so that the total number of start-ups of the heating elements can be reduced, the average water temperature of the inner container can be effectively improved when a single heating element is started up, the heat preservation time after a single heating element is started up can be prolonged, and finally the purpose of reducing the overall energy consumption of the electric water heater can be achieved.

[0014] Specific embodiments of the present application are disclosed in detail in the following description and accompanying drawings, indicating the ways in which the principles of the present application can be employed. It should be understood that the embodiments of the present application are not limited in scope to the specific embodiments described. In the scope of the appended claims and their equivalents, the embodiments of the present application include many changes, modifications and equivalents. Features described and / or shown for one embodiment can be used in the same or similar way in one or more other embodiments, combined with features in other embodiments, or replaced by features in other embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0015] The following drawings are merely intended to schematically illustrate and explain the present application, and do not limit the scope of the present application. Among them:

[0016] Fig. 1 is a structural schematic view of an electric water heater provided in the embodiments of the present application;

[0017] Fig. 2 is an A-A cross-sectional view of the electric water heater provided in the embodiments of the present application in Fig. 1;

[0018] Fig. 3 is a step flow chart of a control method of an electric water heater provided in the embodiments of the present application.

[0019] The reference signs of the present application: 1, inner container; 11, water inlet; 12, water outlet; 2, temperature detection member; 31, first heating rod; 32, second heating rod; 33, third heating rod; 34, fourth heating rod; 35, fifth heating rod; H1: preset distance. DETAILED DESCRIPTION

[0020] In order to make the technical features, objectives and effects of the present application clearer, the specific embodiments of the present application will be described with reference to the drawings.

[0021] The inventors of the present application have found, after in-depth research on electric water heaters, that the existing electric water heaters have unreasonable heat preservation operation logic settings after entering the heat preservation stage, thereby increasing the energy consumption of the electric water heaters.

[0022] Specifically, taking a more typical electric water heater (commercial electric water heater) as an example, after entering the heat preservation stage, the heating element closest to the temperature sensor (referred to as the top heating rod) is selected to work first. The inventors have found, after monitoring the working process of the top heating rod after entering the heat preservation stage, that the top heating rod has a very small average temperature rise of the inner container during its working process in the heat preservation stage, although the total power consumption of the top heating rod from start to exit is not high. Moreover, the time during which the inner container can meet the heat preservation requirement after starting the top heating rod is also very short. After conversion, compared with other heating rods below it, the top heating rod consumes the highest amount of power per 1 degree Celsius of temperature rise for 1 hour of heat preservation.

[0023] Further, the inventors have analyzed the main reasons for the high energy consumption of the existing electric water heaters. The specific reason analysis is as follows:

[0024] Since the top heating rod is close to the temperature sensor, when the top heating rod is started to heat, the water temperature near the top heating rod will be quickly raised in a short time, and the heat transferred upward by the raised water temperature will be detected by the temperature detection member located above the top heating rod. Generally, the controller stores a predetermined target temperature for the heat preservation stage, and when the temperature sensor detects that the water temperature in the inner container reaches the target temperature, the currently working heating rod will be controlled to stop working.

[0025] For the above-mentioned situation of starting the top heating rod to heat, when the temperature sensor detects the target temperature, the actual average water temperature of the inner container does not match the measured temperature detected by the temperature sensor at this time. As a result, the top heating rod stops working too early, which in turn causes the remaining heating elements below the top heating rod to start too early. Overall, the total start-stop times of the heating elements will increase, but the average water temperature of the entire inner container will be low, thereby increasing the energy consumption of the electric water heater.

[0026] The present application provides an electric water heater, a controller and a control method thereof, which can effectively reduce the overall energy consumption of the electric water heater without increasing the cost by optimizing the control logic of the heat preservation stage.

[0027] A control method of an electric water heater is provided in the embodiments of the present application. The control method can be applied to the electric water heater, for example, a commercial electric water heater. Of course, the control method can also be applied to other application scenarios equivalent to the electric water heater. In the embodiments of the present application, the control method is mainly taken as an example for illustration.

[0028] Please refer to FIG. 1 and FIG. 2, the electric water heater can include an inner container 1 for storing water, a temperature detecting member 2 for detecting the temperature of the water in the inner container 1, and a heating assembly arranged below the temperature detecting member 2. The heating assembly is used for heating the water in the inner container 1 in a heating stage and keeping the water in the inner container 1 in a keeping stage. The heating assembly includes an upper heating member and a lower heating member arranged from top to bottom along a height direction. The distance between the upper heating member and the temperature detecting member 2 is within a preset distance H1. Please refer to FIG. 3, the control method can include: in the keeping stage, only starting at least part of the lower heating member to keep warm or making the number of times of keeping warm of the upper heating member less than the number of times of keeping warm of the lower heating member.

[0029] In the embodiments of the present application, the electric water heater can mainly include the inner container 1, the temperature detecting member 2, the heating assembly, and the like. In addition, the electric water heater can also include a controller and the like electrically connected with the temperature detecting member 2 and the heating assembly.

[0030] The inner container 1 can include a hollow container body. The inner container 1 can be divided into a horizontal type and a vertical type according to different installation modes. For example, when the overall extension direction of the inner container 1 is horizontal, the inner container 1 is a horizontal type. Or, as shown in FIG. 1 or FIG. 2, when the overall extension direction of the inner container 1 is vertical, the inner container 1 is a vertical type. In the embodiments of the present application, the inner container 1 is mainly taken as an example for illustration as a vertical type. When the inner container 1 is in other forms, it can be analogously referred to the present application.

[0031] The inner container 1 can be provided with a water inlet 11 and a water outlet 12. The water inlet 11 is used to supply water to be heated into the inner container 1, and the water outlet 12 can output the water heated by the heating assembly in the inner container 1 to the outside. For the water in the inner container 1, the water temperature decreases from top to bottom along the direction of gravity without external disturbance. In order to output more hot water in the inner container 1 to the user during a water use process, thereby providing more hot water to the user, the water outlet 12 can be arranged close to the top of the inner container 1, and the water inlet 11 can be arranged close to the bottom of the inner container 1. For example, the water outlet 12 can be arranged on the top cover of the inner container 1, and the water inlet 11 can be arranged on the side wall close to the bottom wall of the inner container 1. When the user uses water, the external normal temperature water enters the inner container 1 through the lower water inlet 11, and the hot water with higher temperature is pushed out of the inner container 1 from the higher position water outlet 12 from bottom to top.

[0032] The temperature detection member 2 is used to detect the water temperature in the inner container 1. The temperature detection member 2 is located above the heating assembly. Specifically, the form and installation method of the temperature detection member 2 can be adaptively selected according to the actual product configuration, and the present application does not make a unique limitation here. For example, the temperature detection member 2 can be in the form of a temperature probe, which can be fixed on the inner surface of the container wall of the inner container 1, or can be arranged on the outer surface of the container wall of the inner container 1, or can be arranged through the container wall of the inner container 1.

[0033] The heating assembly is used to heat the water in the inner container 1. The heating assembly is located below the temperature detection member 2, and the heating assembly can include a plurality of heating members along the height direction. Specifically, the number of heating members in the heating assembly can include at least two. For example, as shown in FIG. 1 or FIG. 2, the heating assembly can include five heating rods arranged from top to bottom along the height direction, which are first heating rod 31, second heating rod 32, third heating rod 33, fourth heating rod 34 and fifth heating rod 35. Of course, the number of the heating assembly is not limited to the above examples, and it can also be more or less, for example, it can be 3 or 4, or more than 5. The heating power of the heating members with different height positions can be the same or different. In the embodiments of the present application, a plurality of heating members with the same heating power are mainly taken as examples for illustration.

[0034] When the electric water heater is in different stages, the main functions of the heating assembly are different. The electric water heater can include a heating stage and a heat preservation stage.

[0035] The heating stage includes two cases: the inner container 1 is filled with water at the first time of water inlet, and the inner container 1 is supplemented with water through the water inlet 11 during use. In the heating stage, the heating assembly is used to heat and raise the temperature of the water in the inner container 1 to meet the user's demand for hot water. Generally, in the heating stage, all heating elements in the heating assembly can be started at the same time to quickly raise the temperature of the water in the inner container 1 to the target outlet water temperature and to increase the amount of hot water once output by the electric water heater. Of course, in the present application, the specific working mode of the heating assembly in the heating stage is not specifically limited, and it can be flexibly adjusted according to different scene requirements and user requirements.

[0036] In the heat preservation stage, the heating assembly is used to heat and preserve the water in the inner container 1, so as to maintain the water temperature in the inner container 1 above the set heat preservation temperature. The heat preservation temperature can be pre-stored in the controller, and the heat preservation temperature can also be set according to user requirements, or the heat preservation temperature can be adaptively adjusted according to the working condition of the electric water heater. Generally, in the heat preservation stage, the water inlet 11 in the inner container 1 is not supplemented with cold water. Of course, the definitions of the above heating stage and heat preservation stage can also be explained according to the general definition in the prior art.

[0037] When the electric water heater is in the heat preservation stage, the temperature detection element 2 is used to detect the water temperature in the inner container 1, and when the water temperature in the inner container 1 reaches the condition for starting the heating assembly to heat, the corresponding heating element in the heating assembly is started to raise the water temperature in the inner container 1.

[0038] The condition for starting the heating assembly to heat can be that the current water temperature in the inner container 1 decreases to the heat preservation temperature. For different heating elements, the corresponding heat preservation temperature for starting heating can be completely the same, of course, it can also be different. For example, when the heat preservation temperature for starting heating is the same, when the temperature detection element 2 detects that the current water temperature in the inner container 1 decreases to the heat preservation temperature, the corresponding heating element can be started to heat to raise the water temperature in the inner container 1.

[0039] In the present application, the heating assembly can include an upper heating element and a lower heating element arranged from top to bottom along the height direction. The distance from the upper heating element to the temperature detection element 2 is within a preset distance H1.

[0040] The upper heating element is a heating element within a preset distance H1 from the temperature detection element 2. The number of upper heating elements can be determined according to the distance from the temperature detection element 2.

[0041] As shown in FIG. 2, in the predetermined distance range, the upper heating member can include the first heating rod 31, and the number of the upper heating member is one.

[0042] The upper heating member can be a top heating member closest to the temperature detection member 2. The top heating member can be the first heating rod 31 shown in FIG. 1 or FIG. 2. The control method can be that, in the holding stage, the top heating member is not started, and only at least part of the lower heating member is started to hold or the number of times that the top heating member is started to hold is less than the number of times that the lower heating member is started to hold. In the embodiments of the present application, the upper heating member is mainly taken as the first heating rod 31 for example.

[0043] In an embodiment, the preset distance H1 of the upper heating member to the temperature detection member 2 can be within 320 mm.

[0044] When the distance of the upper heating member to the temperature detection member 2 is within 320 mm, it means that the distance of the upper heating member to the temperature detection member 2 is relatively short, and when the upper heating member is started to heat, the temperature detected by the temperature detection member 2 does not match the average water temperature of the inner container 1, which is easy to cause the temperature detection member 2 to reach the preset temperature too early, and thus the upper heating member is caused to exit heating too early. The preset temperature can be pre-stored in the controller, for example, can be a temperature value or a temperature interval. The preset temperature matches the average water temperature of the inner container 1, and the two are equivalent or equal. Generally, when the water temperature detected by the temperature detection member 2 reaches the preset temperature, it means that the average water temperature of the inner container 1 reaches the target water temperature.

[0045] The upper heating member can be a heating member with poor heat conversion benefit in the holding stage. The upper heating member has a small effect on the increase of the average water temperature of the inner container 1 in the heating process, and the upper heating member is caused to exit heating too early when the average water temperature of the inner container 1 is far from the set target water temperature after the upper heating member is started in the holding stage. The specific number of the upper heating member can be determined based on the distance of the heating member to the temperature detection member 2, and accordingly, the upper heating member and the lower heating member can be distinguished.

[0046] It should be noted that the specific value of the preset distance H1 can also be affected by the size configuration of the inner container 1, such as the volume and the diameter of the inner container 1, and in the present application, the numerical value is set mainly for the size of the conventional inner container 1. Of course, the present application also does not exclude the case that the preset distance H1 slightly exceeds the above range. When the preset distance H1 slightly exceeds the above numerical range, the same effect as the above boundary value can also be achieved.

[0047] In another embodiment, the ratio of the distance from the upper heating element to the temperature detecting element 2 to the height of the inner container 1 is in the range of 0.1-0.25.

[0048] In the present embodiment, the inner container 1 has a predetermined height. For example, the height of the inner container 1 can be the distance from the bottom wall to the top cover of the inner container 1. The distance from the upper heating element to the temperature detecting element 2 can be the distance between the highest position of the upper heating element and the lowest position of the temperature detecting element 2 in the height direction.

[0049] The ratio of the distance from the upper heating element to the temperature detecting element 2 to the height of the inner container 1 can be used to determine the number and position of the upper heating elements. Compared with the above embodiment, the determination of the upper heating elements takes into account the height of the inner container 1, and thus has better universality.

[0050] It should be noted that the specific values of the boundaries of the ratio can also be affected by the size and configuration of the inner container 1, such as the volume and the diameter of the inner container 1. In the present application, the values are mainly set according to the size of the inner container 1 in the current market. Of course, the preset distance H1 in the present embodiment can also exceed the above range. When the preset distance H1 exceeds the above range, the same effect as the boundary values can also be achieved.

[0051] The electric water heater can also be provided with a controller, and the controller can store the operation logic of the heating assembly in the heat preservation stage.

[0052] When the electric water heater enters the heat preservation stage, the number of times of starting the upper heating element for heat preservation can be less than the number of times of starting the lower heating element for heat preservation, so that the upper heating element with a lower heat conversion benefit reduces the number of start-ups, or even does not start up, thereby reducing the total number of start-ups of the heating elements, effectively increasing the average water temperature of the inner container 1 when a single heating element starts up, prolonging the heat preservation time after starting up a single heating element, and ultimately achieving the purpose of reducing the overall energy consumption of the electric water heater. Specifically, the present application can improve the original two-level energy efficiency to one-level energy efficiency.

[0053] The control method provided by the present application will be described in detail below in combination with FIG. 3 and specific embodiments.

[0054] The electric water heater includes a heating stage and a heat preservation stage. During use of the water heater, whether the heating stage needs to transition to the heat preservation stage can be determined according to the temperature parameter and / or flow parameter of the water in the inner container 1 of the electric water heater.

[0055] In one embodiment, the control method can comprise: after the heating stage of the electric water heater is completed, judging the water usage of the user according to the temperature parameter and / or flow parameter of the water in the inner container 1 of the electric water heater, and if the water usage of the user is not greater than a first preset value within a preset time, controlling the electric water heater to enter the heat preservation stage.

[0056] In the present embodiment, the temperature of the water in the inner container 1 and / or the flow parameter can be monitored by at least one of the temperature detection member 2, the flow detection member, etc., the water usage of the user is judged based on the monitoring result, and then it is judged whether the electric water heater needs to enter the heat preservation stage.

[0057] For the electric water heater, generally, a temperature detection member 2 is provided, and when the heating stage of the electric water heater is completed, the average water temperature in the inner container 1 reaches a target set temperature. The target set temperature can be a certain temperature or temperature range stored in the controller, and the specific value is not uniquely determined herein. The electric water heater can continuously detect the change of the water temperature in the inner container 1 by using the temperature detection member 2, and when the water temperature in the inner container 1 decreases greatly in a short time (i.e., the water temperature decreases rapidly), it can be indicated that the user is in the water usage state at this time, and the heating assembly can be started to continue heating. When the average water temperature in the inner container 1 reaches the target set temperature, if the subsequent temperature slowly decreases in a short time, for example, if the time required for decreasing 1 degree Celsius is greater than 2 hours, it is indicated that the electric water heater enters the heat preservation stage.

[0058] For the electric water heater, a flow sensor can also be provided at the water outlet 12 and / or the water inlet 11. When the average water temperature in the inner container 1 reaches the target set temperature, if the water usage of the current user is less than a preset water usage (a first preset value) within a period of time based on the flow signal detected by the flow sensor, it is indicated that the electric water heater enters the heat preservation stage. The first preset value can be determined comprehensively according to the volume of the inner container 1, etc., and can be a specific value or a value range, which is not uniquely limited herein.

[0059] Further, the control method can also comprise: after the electric water heater enters the heat preservation stage, judging the water usage of the user according to the temperature parameter and / or flow parameter of the water in the inner container 1 of the electric water heater, and if the water usage of the user is not greater than a second preset value within a preset time, controlling the electric water heater to be in the heat preservation stage.

[0060] In the embodiment, when the electric water heater enters the heat preservation stage, the water use condition of the current user can be continuously determined according to the temperature parameter and / or the flow parameter of the water in the inner container 1 of the electric water heater, and when it is determined that the user does not have a large amount of water use, the electric water heater can be maintained in the heat preservation stage.

[0061] Specifically, the specific manner of determining the water use condition of the current user is the same as that described in the above embodiment, and will not be described herein again. The second preset value can be the same as the first preset value, or the second preset value can be different from the first preset value, and the specific numerical value is not limited herein.

[0062] In one embodiment, the lower heating member includes a plurality of lower heating elements, and the step of starting only at least part of the lower heating member to perform heat preservation is specifically: in the heat preservation stage, the upper heating member is not started, and only the preset lower heating element of the plurality of lower heating elements is controlled to perform heat preservation on the water in the inner container 1 in a preset order.

[0063] In the embodiment, the lower heating member can include a plurality of heating elements below the upper heating member. As shown in FIG. 2, for example, when the upper heating member is the first heating rod 31, the lower heating member includes all the heating rods below the first heating rod 31, such as the second heating rod 32, the third heating rod 33, the fourth heating rod 34, and the fifth heating rod 35. Of course, the combination of the lower heating member can be different according to the height of the inner container 1, the distance between the heating rods, the power of the heating rods, and the like, and in the present application, only the above combination is exemplified.

[0064] In the heat preservation stage, the upper heating member can be completely not started, and the lower heating member below the upper heating member is started. Specifically, the control of the preset lower heating element of the plurality of lower heating elements to perform heat preservation on the water in the inner container 1 in a preset order is that all or part of the heating elements in the lower heating member are started to perform heat preservation on the water in the inner container 1 in turn, so that the upper heating member can be avoided, thereby effectively reducing the energy consumption of the electric water heater.

[0065] When part of the heating elements are started, the number of the part of the heating elements is at least 2, so that in the heat preservation stage, a plurality of lower heating elements can work in turn, thereby being beneficial to prolong the service life of the heating elements.

[0066] In a specific embodiment, the step of only controlling the preset lower heating elements of the plurality of lower heating elements to sequentially heat the water in the inner container 1 in a preset order specifically includes: sequentially controlling at least one heating element of the plurality of lower heating elements to heat the water in the inner container 1 in an order from top to bottom in the height direction.

[0067] In the present embodiment, the plurality of lower heating elements can include a plurality of heating rods arranged sequentially from top to bottom in the height direction, for example, the second heating rod 32, the third heating rod 33, the fourth heating rod 34, and the fifth heating rod 35. The preset lower heating elements of the plurality of lower heating elements can be all the lower heating elements, or the present application does not exclude starting some of the plurality of lower heating elements to heat the water in the inner container 1.

[0068] In the heating stage, taking the case where all the plurality of heating rods participate in heating as an example, when the water temperature in the inner container 1 decreases to the heating temperature, the second heating rod 32 is started to increase the water temperature in the inner container 1. When the second heating rod 32 is heated for a period of time, the temperature detection piece 2 detects that the current water temperature reaches the preset temperature, and the second heating rod 32 stops heating, and the water in the electric water heater enters a slow cooling process.

[0069] When the water temperature in the inner container 1 decreases to the heating temperature again, the third heating rod 33 is started to increase the water temperature in the inner container 1. When the third heating rod 33 is heated for a period of time, the temperature detection piece 2 detects that the current water temperature reaches the preset temperature, and the third heating rod 33 stops heating, and the water in the electric water heater enters a slow cooling process.

[0070] When the water temperature in the inner container 1 decreases to the heating temperature again, the fourth heating rod 34 is started to increase the water temperature in the inner container 1. When the fourth heating rod 34 is heated for a period of time, the temperature detection piece 2 detects that the current water temperature reaches the preset temperature, and the fourth heating rod 34 stops heating, and the water in the electric water heater enters a slow cooling process.

[0071] When the water temperature in the inner container 1 decreases to the heating temperature again, the fifth heating rod 35 is started to increase the water temperature in the inner container 1. When the fifth heating rod 35 is heated for a period of time, the temperature detection piece 2 detects that the current water temperature reaches the preset temperature, and the fifth heating rod 35 stops heating, and the water in the electric water heater enters a slow cooling process.

[0072] Thus, a heating and heating cycle is formed, and in the subsequent heating stage, each heating rod in the lower heating element can be controlled according to the control logic of the above-mentioned heating and heating cycle to work periodically.

[0073] In the present embodiment, when the lower heating element is started to heat the water in the inner container 1, the upper heating rod is preferentially started to heat, i.e. the heating is started in a top-down sequence, so that the water near the upper part of the water outlet 12 can be preferentially heated in a small amount, thereby being able to timely and efficiently meet the user's use demand when the user has a water demand. In addition, since the user's water demand is relatively small during the heat preservation stage, when the upper heating rod is started to heat first, the lower heating rod is avoided to start to heat and heat all the water in the inner container 1 at one time, and at this time the user has no use demand, all the heated water is not utilized, and energy is wasted.

[0074] In the above-mentioned embodiments of the present application, the embodiment in which the upper heating element, specifically the top heating element (i.e. the first heating rod 31), is not started to heat during the heat preservation stage, and only at least part of the lower heating element is started to heat, is mainly exemplified.

[0075] For the embodiment in which the number of times of heat preservation of the top heating element is less than the number of times of heat preservation of the lower heating element, the first heating rod 31 can be started in a certain heating period, and the first heating rod 31 can not be started in the adjacent next period. Specifically, the frequency of starting the first heating rod 31 in different periods can be designed according to the actual working condition, etc. In theory, the fewer the number of times of starting the first heating rod 31, the more conducive to reducing the energy consumption of the electric water heater.

[0076] For the electric water heater, when it is converted from the heating stage to the heat preservation stage, it can include a plurality of different sub-stages.

[0077] In one embodiment, the lower heating element includes a plurality of lower heating elements, and the control method comprises: from the time when the electric water heater enters the heat preservation stage to the first preset time, if the electric water heater is still in the heat preservation stage and the heat preservation trigger condition is met, only the lowermost lower heating element of the plurality of lower heating elements is controlled to heat preservation or the lower heating element other than the top lower heating element of the plurality of lower heating elements is controlled to heat preservation.

[0078] In the embodiment, the lower heating element includes a plurality of lower heating elements, for example, at least two lower heating elements. When the electric water heater just enters the heat preservation stage from the heating stage, that is, from the beginning of entering the heat preservation stage to the first preset time period, the user still has a large water demand. At this time, in order to better meet the user's water demand, the bottommost lower heating element can be controlled to heat preservation when the electric water heater meets the heat preservation trigger condition, so as to effectively raise the temperature of all the water in the inner container 1, and provide the user with the most amount of hot water when the user uses water. Since the bottommost lower heating element (for example, the fifth heating rod 35) is farthest from the temperature detection element 2, when the bottommost lower heating element is started, the average water temperature in the inner container 1 can be maximally raised.

[0079] Alternatively, when the electric water heater meets the heat preservation trigger condition, the non-top lower heating element of the plurality of lower heating elements can also be controlled to heat preservation. The main purpose of controlling the non-top lower heating element of the plurality of lower heating elements is also to use the heating element close to the bottom as much as possible, which can produce an effect similar to that of using the bottommost lower heating element. The difference is that when multiple non-top lower heating elements are used for heat preservation at the same time, for example, the fourth heating rod 34 and the fifth heating rod 35 are started at the same time, the water temperature is raised faster than when only the fifth heating rod 35 is started, which is more suitable for the scenario that the user is likely to have a water demand in a short time.

[0080] The heat preservation trigger condition includes that the temperature detection element 2 detects that the water temperature in the inner container 1 drops to below the difference between the set outlet water temperature and the preset hysteresis temperature.

[0081] The time period from entering the heat preservation stage to the first preset time can be a fixed time length stored in the controller, of course, it can also be adjusted according to different water habits of the user, or it can also be determined after learning the water habits of the user by the self-learning module, and the specific value is not limited herein.

[0082] Overall, the set outlet water temperature and the preset hysteresis temperature can be set and adjusted by the user. Overall, the set outlet water temperature is theoretically the temperature output by the electric water heater to the water end, and the user can adjust the set outlet water temperature according to the water demand, and the specific value is not limited herein. In different use scenarios, the user has different demands for the preset hysteresis temperature.

[0083] Scenario one: for example, when the water outlet of the electric water heater is directly provided to the user for use, the general human body temperature is 2-3 degrees Celsius, at this time, in order to ensure that the user has a constant temperature experience, the return difference temperature can be set to about 2 degrees Celsius;

[0084] Scenario two: for example, in a commercial scenario, the water outlet of the electric water heater first flows into a water tank, and then is output to the user after mixing water, and under the mixing effect of the water tank (assuming that 48 degrees Celsius of water is added to a water tank with a water temperature of 60 degrees Celsius, the outlet water temperature can still reach about 55 degrees Celsius), the return difference temperature value can be increased, for example, it can be set to about 11 degrees Celsius. When the preset return difference temperature is set to be larger, the starting frequency of the electric device in the water heater can be reduced, and the service life can be prolonged.

[0085] It should be noted that the controller of the electric water heater can be provided with a self-learning module, which can learn the user's water usage habits, thereby identifying the user's water usage habits. Based on the user's water usage habits, specific control can be performed, and it can be selected whether to control only the bottommost lower heating element of the plurality of lower heating elements for heat preservation or to control the lower heating element other than the top of the plurality of lower heating elements for heat preservation, thereby intelligently matching the user's use demand, and also taking into account the energy efficiency of the electric water heater.

[0086] In one embodiment, the lower heating element includes a plurality of lower heating elements, and the control method can further include: from a first preset time after the electric water heater enters the heat preservation stage to a second preset time, if the electric water heater is still in the heat preservation stage and meets the heat preservation trigger condition, controlling the preset lower heating element of the plurality of lower heating elements to heat the water in the inner container 1 in a preset order.

[0087] In the above embodiment, when the electric water heater enters the heat preservation stage to the first preset time, it belongs to the first heat preservation stage in the heat preservation stage. From the first preset time after the electric water heater enters the heat preservation stage to the second preset time, it belongs to the second heat preservation stage in the heat preservation stage. In the second heat preservation stage, the user's water demand is relatively low, and if the electric water heater is still in the heat preservation stage and meets the heat preservation trigger condition, the preset lower heating element of the plurality of lower heating elements can be controlled to heat the water in the inner container 1 in a preset order.

[0088] The heat preservation trigger condition can refer to the specific description in the above embodiment, which will not be repeated here.

[0089] The first preset time to the second preset time period can be a fixed time length stored in the controller, of course, it can also be adjusted according to the different water habits of the user, or it can also be determined by learning the water habits of the user using a self-learning module. The specific value is not uniquely limited herein.

[0090] The step of controlling the preset heating elements in the plurality of lower heating elements to sequentially heat the water in the inner container 1 in a preset order, specifically includes: sequentially controlling at least one lower heating element in the plurality of lower heating elements to heat the water in the inner container 1 in the order from top to bottom in the height direction.

[0091] The control of the lower heating elements in the preset order to sequentially heat the water in the inner container 1 can refer to the description of the above embodiments, for example, sequentially starting the second heating rod 32, the third heating rod 33, the fourth heating rod 34, and the fifth heating rod 35 to form a heating cycle, and then repeating the heating cycle.

[0092] Of course, in some special cases, the application also does not exclude skipping the start of one or more heating rods in a certain period or certain periods. For example, when a certain heating rod is out of order, the out-of-order heating rod can be automatically skipped (not started); or the heating power of a certain heating rod is special and does not meet the heating requirement, the heating rod can also be not started.

[0093] In an embodiment, the heating stage of the electric water heater can also include a third heating stage, which is located after the second heating stage. After the second heating stage, the user's water habits are monitored, and it is found that the user does not use water in the second heating stage. On the basis of the second heating stage, the temperature detection member 2 can be used to further monitor the water temperature in the inner container 1. If it is monitored that the user does not use water in a longer period of time (for example, in 48 hours, the time required for the temperature to decrease by 1℃ is greater than 2h), it can be inferred that the user may not use water in the future. On the basis of the operation logic of the second heating stage, the preset temperature of the temperature detection member 2 can be further optimized to reduce the overall energy consumption of the electric water heater.

[0094] The electric water heater provided in the embodiments of the application includes the above-mentioned controller. The electric water heater can achieve the technical effects realized by the controller embodiments by setting the controller. For details, please refer to the specific description of the above embodiments, which will not be repeated here.

[0095] In one embodiment, the electric water heater can further comprise: an inner container 1 for storing water; a temperature detecting member 2 for detecting the temperature of the water in the inner container 1; a heating assembly arranged below the temperature detecting member 2, the heating assembly being used for heating the water in the inner container 1 in a heating stage and for keeping the water in the inner container 1 in a keeping stage, the heating assembly comprising an upper heating member and a lower heating member arranged from top to bottom along a height direction, the distance from the upper heating member to the temperature detecting member 2 being within a preset distance H1.

[0096] In one embodiment, the distance from the upper heating member to the temperature detecting member 2 is within 320 mm. In one embodiment, the ratio of the distance from the upper heating member to the temperature detecting member 2 to the height of the inner container 1 is between 0.1 and 0.25.

[0097] In the present embodiment, the inner container 1, the temperature detecting member 2, the heating assembly and other components in the electric water heater and the technical effects that can be achieved by the electric water heater can be referred to the specific description of the control method embodiments of the electric water heater, which will not be repeated here.

[0098] The above description is merely illustrative of the embodiments of the present application, and is not intended to limit the scope of the present application. Any equivalent changes and modifications made by those skilled in the art without departing from the spirit and principle of the present application shall fall within the scope of the present application.

Claims

1. A control method of an electric water heater, wherein, the electric water heater comprises: an inner container for storing water, a temperature detecting member for detecting a water temperature in the inner container, a heating assembly arranged below the temperature detecting member, the heating assembly being configured to heat the water in the inner container in a heating phase and to keep the water in the inner container in a keeping phase, the heating assembly comprising an upper heating member and a lower heating member arranged from top to bottom along a height direction, the upper heating member being within a preset distance from the temperature detecting member, and the control method comprises: in the keeping phase, only starting at least part of the lower heating member to keep the water or causing the upper heating member to keep the water less frequently than the lower heating member.

2. The control method of the electric water heater according to claim 1, wherein the lower heating member comprises a plurality of lower heating elements, and the step of only starting at least part of the lower heating member to keep the water in the keeping phase specifically comprises: in the keeping phase, not starting the upper heating member, and only controlling preset lower heating elements of the plurality of lower heating elements to keep the water in the inner container in a preset order.

3. The control method of the electric water heater according to claim 2, wherein the step of only controlling preset lower heating elements of the plurality of lower heating elements to keep the water in the inner container in a preset order specifically comprises: controlling at least one lower heating element of the plurality of lower heating elements to keep the water in the inner container in a top-to-bottom order along the height direction.

4. The control method of an electric water heater according to claim 1, wherein the lower heating member comprises a plurality of lower heating elements, and the control method comprises: from a time period starting from when the electric water heater enters the keeping phase to a first preset time, if the electric water heater is still in the keeping phase and a keeping trigger condition is met, only controlling a bottommost lower heating member of the plurality of lower heating elements to keep the water or controlling non-top lower heating members of the plurality of lower heating elements to keep the water.

5. The control method of an electric water heater according to claim 4, wherein the lower heating member comprises a plurality of lower heating elements, and the control method further comprises: from a time period starting from a first preset time after the electric water heater enters the keeping phase to a second preset time, if the electric water heater is still in the keeping phase and a keeping trigger condition is met, controlling preset lower heating elements of the plurality of lower heating elements to keep the water in the inner container in a preset order.

6. The control method of an electric water heater according to claim 4 or 5, wherein the keeping trigger condition comprises: the temperature detecting member detecting that the water temperature in the inner container drops to below a difference between a set water outlet temperature and a preset back-off temperature.

7. The control method of an electric water heater according to claim 5, wherein the step of controlling preset lower heating elements of the plurality of lower heating elements to keep the water in the inner container in a preset order specifically comprises: controlling at least one lower heating element of the plurality of lower heating elements to keep the water in the inner container in a top-to-bottom order along the height direction.

8. The control method of an electric water heater according to claim 1, wherein the distance from the upper heating member to the temperature detecting member is within 320 mm.

9. The control method of an electric water heater according to claim 1, wherein a ratio of the distance from the upper heating member to the temperature detecting member to a height of the inner container is within 0.1-0.

25.

10. The control method of an electric water heater according to claim 1, wherein The control method further comprises: after the heating stage of the electric water heater is completed, determining the water usage of the user according to the temperature parameter and / or flow parameter of the water in the inner container of the electric water heater, and if the water usage of the user is not greater than a first preset value within a preset time, controlling the electric water heater to enter the heat preservation stage.

11. The control method of an electric water heater according to claim 10, wherein The control method further comprises: after the electric water heater enters the heat preservation stage, determining the water usage of the user according to the temperature parameter and / or flow parameter of the water in the inner container of the electric water heater, and if the water usage of the user is not greater than a second preset value within a preset time, controlling the electric water heater to be in the heat preservation stage.

12. The control method of an electric water heater according to claim 1, wherein The upper heating member is a top heating member closest to the temperature detecting member, and the control method specifically comprises: in the heat preservation stage, the top heating member is not started, and only at least part of the lower heating members are started to perform heat preservation or the number of times that the top heating member performs heat preservation is less than the number of times that the lower heating members perform heat preservation.

13. A controller, wherein, The controller is configured to perform the control method of the electric water heater according to any one of claims 1 to 12.

14. An electric water heater wherein, The electric water heater comprises the controller according to claim 13.

15. The electric water heater as claimed in claim 14, wherein, The electric water heater further comprises: an inner container for storing water; a temperature detecting member for detecting the water temperature in the inner container; a heating assembly arranged below the temperature detecting member, the heating assembly being used for heating the water in the inner container in a heating stage and for heat preserving the water in the inner container in a heat preservation stage, the heating assembly comprising upper heating members and lower heating members arranged from top to bottom along a height direction, and the distance from the upper heating members to the temperature detecting member being within a preset distance.

16. The electric water heater as claimed in claim 15, wherein, The distance from the upper heating members to the temperature detecting member is within 320 mm.

17. The electric water heater as claimed in claim 15, wherein, The ratio of the distance from the upper heating members to the temperature detecting member to the height of the inner container is between 0.1 and 0.25.

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