Fault determination method and device for heating device and electric water heater

Abstract

The embodiment of the present application discloses a method, device and electric water heater for determining the fault of a heating device. When the heating device includes at least two heating units in operation and arranged in parallel on a branch of the same phase line, and the heating unit includes a heating element and a switch for controlling the heating element, the method includes: obtaining the main current value of the phase line when the operation state of the heating unit is not changed, and determining that the heating element in at least one heating unit has a fault when the main current value is not greater than a first current value; obtaining the change value of the main current value caused by turning the switch on and off, and determining that the heating element controlled by the switch has a fault when the change value of the main current value is not greater than a preset change value. Through the embodiment of the present application, the fault diagnosis of multiple heating elements in the heating device can be achieved at low cost and with high reliability.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of device fault diagnosis, and in particular, to a method and device for determining a fault of a heating device, and an electric water heater. Background Art

[0002] Commercial high-power electric water heaters are generally used in high-flow bathing scenarios such as hotels, guesthouses, bath centers, hospitals, and homes. Commercial high-power electric water heaters have a large number of heating elements. If a heating element fails, it will affect the user's water experience.

[0003] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because they are described in the background technology section of the present application. Summary of the invention

[0004] In the related technology, a separate current monitoring device connected in series with the heating element can be provided for each heating element, and the faulty heating element can be found by detecting the branch current value passing through each heating element. Therefore, for the fault detection scenario of multiple heating elements, the detection cost is relatively high.

[0005] In response to at least one of the above-mentioned problems, an embodiment of the present application provides a fault determination method, device and electric water heater for a heating device, which can determine whether a heating element has a fault based on the main current value, and determine the faulty heating element based on the change value of the main current. In this way, fault diagnosis of multiple heating elements in a heating device can be achieved reliably and at low cost.

[0006] The specific technical solution of the embodiment of this application is:

[0007] According to a first aspect of an embodiment of the present application, a method for determining a fault of a heating device is provided. When the heating device includes at least two heating units in operation and arranged in parallel on a branch of the same phase line, and the heating unit includes a heating element and a switch for controlling the heating element, the method includes:

[0008] When the operation state of the heating unit is not changed, obtaining the main current value of the phase line, and determining that a heating element in at least one heating unit fails when the main current value is not greater than the first current value;

[0009] A change value of the trunk current value caused by turning the switch on and off is obtained, and when the change value of the trunk current value is not greater than a preset change value, it is determined that a heating element controlled by the switch fails.

[0010] According to a second aspect of an embodiment of the present application, a method for determining a fault of a heating device is provided. When the working current of the heating device is a three-phase power supply current, and each phase line of the three phase lines includes at least two heating units in operation and arranged in parallel in a branch, the heating unit includes a heating element and a switch for controlling the heating element, the method includes:

[0011] When the operation state of the heating unit is not changed, obtaining the main current value of each phase line, and when the main current value is not greater than the first current value, determining that a heating element in at least one heating unit on the phase line where the main current is located fails;

[0012] The change value of the main current value caused by turning on and off the switch on the phase line where the heating element fails is obtained. When the change value of the main current value is not greater than a preset change value, it is determined that the branch where the heating element controlled by the switch is located fails.

[0013] According to a third aspect of an embodiment of the present application, a fault determination device for a heating device is provided, comprising a processor, wherein the processor is configured to execute the fault determination method for the heating device described in the first aspect or the second aspect.

[0014] According to the fourth aspect of the embodiment of the present application, there is provided an electric water heater, comprising: a heating device, the heating device comprising at least two heating units connected in parallel in branches of the same phase line, the heating unit comprising a heating element and a switch for controlling the operation of the heating element; a fault determination device of the heating device described in the third aspect; a water circuit assembly, the heating element being used to heat water in the water circuit assembly.

[0015] The beneficial effect of the embodiments of the present application is that it is possible to determine whether a heating element has failed based on the main current value, and to determine the failed heating element based on the change in the main current value. Thus, fault diagnosis of multiple heating elements in a heating device can be achieved at low cost and with high reliability.

[0016] With reference to the following description and drawings, the specific embodiments of the present application are disclosed in detail, indicating the manner in which the principles of the present application can be adopted. It should be understood that the embodiments of the present application are not limited in scope. Within the spirit and scope of the appended claims, the embodiments of the present application include many changes, modifications and equivalents. The features described and / or shown for one embodiment can be used in one or more other embodiments in the same or similar manner, combined with the features in other embodiments, or replace the features in other embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are only for explanation purposes and are not intended to limit the scope of the present application in any way. In addition, the shapes and proportional dimensions of the various components in the drawings are only for illustration purposes, and are used to help understand the present application, and are not intended to specifically limit the shapes and proportional dimensions of the various components of the present application. Those skilled in the art can select various possible shapes and proportional dimensions to implement the present application according to the specific circumstances under the guidance of the present application.

[0018] Figure 1 A schematic diagram of a fault determination method in an embodiment of the present application;

[0019] Figures 2 to 4 Schematic diagram of a heating circuit in an embodiment of the present application;

[0020] Figure 5 This is a schematic diagram of an implementation of operation 102 in an embodiment of the present application;

[0021] Figure 6 A schematic diagram of a fault determination method in an embodiment of the present application;

[0022] Figure 7 and Figure 8 This is a schematic diagram of the connection relationship of the heating units in the embodiment of the present application;

[0023] Fig. 9 A schematic diagram of a fault determination method in an embodiment of the present application;

[0024] Fig.10 A schematic diagram of the fault determination device in an embodiment of the present application;

[0025] Fig.11 This is a schematic diagram of the electric water heater in the embodiment of the present application;

[0026] Fig.12 This is a schematic diagram of the electric water heater in an embodiment of the present application. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present application by those skilled in the art all fall within the scope defined by the claims attached to the present application.

[0028] In the embodiments of the present application, the terms "first", "second", etc. are used to distinguish different elements in terms of title, but do not indicate the spatial arrangement or temporal order of these elements, etc., and these elements should not be limited by these terms. The term "and / or" includes any one and all combinations of one or more of the associated listed terms. The terms "comprising", "including", "having", etc. refer to the presence of the stated features, elements, components or components, but do not exclude the presence or addition of one or more other features, elements, components or components.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0030] Embodiments of the first aspect

[0031] An embodiment of the first aspect of the present application provides a method for determining a fault of a heating device, when the heating device comprises at least two heating units in operation and arranged in parallel on a branch of the same phase line, the heating unit comprising a heating element and a switch for controlling the heating element, Figure 1 is a schematic diagram of the fault determination method, such as Figure 1 As shown, the method includes:

[0032] 101, when the operating state of the heating unit is not changed, obtaining a main current value of the phase line, and when the main current value is not greater than a first current value, determining that a heating element in at least one heating unit fails;

[0033] 102, obtaining a change value of the trunk current value caused by turning on and off the switch, and when the change value of the trunk current value is not greater than a preset change value, determining that a heating element controlled by the switch fails.

[0034] In some embodiments, the heating device includes at least two (hereinafter referred to as M) heating units in operation and arranged in parallel on a branch of the same phase line, wherein M is an integer not less than 2, and the M heating units are arranged in parallel on the branch of the same phase line. By providing a working current to the heating unit, the heating unit is heated and generates heat, thereby realizing the heating function. The working current of the heating device can be a single-phase power supply current, a two-phase power supply current, or a three-phase power supply current, etc. The embodiments of the present application are not limited to this. For example, when the working current is a single-phase power supply current, the heating device only includes one phase line, Figure 2 It is a schematic diagram of the heating circuit. Figure 2As shown, that is, the M heating units are arranged in parallel on the M branches of the one phase line; when the working current is a three-phase supply current, the heating device comprises three phase lines, Figure 3 This is another schematic diagram of the heating circuit. Figure 3 As shown, the three phase lines are U phase, V phase and W phase, that is, on each of the three phase lines, there are M heating units arranged in parallel on M branches (M=4), and examples are not given here one by one.

[0035] In addition, when working, the heating device may include, in addition to M heating units in operation and arranged in parallel on the branch of the same phase line, P heating units in a stopped operation state (P is an integer greater than or equal to 0), and the P heating units are arranged in parallel with the aforementioned M heating units on the branch of the same phase line. Figure 4 This is another schematic diagram of the heating circuit. Figure 4 As shown, Figure 4 The dotted part refers to the heating unit in the stopped state, and the solid part refers to the heating unit in the running state. M=4, P=1. On each of the three phase lines, there are M+P heating units arranged in parallel on M+P branches.

[0036] It should be noted that, in the above examples, each branch includes a heating unit, but the embodiments of the present application are not limited to this. Each branch may include at least two heating elements connected in series, which will not be described one by one here.

[0037] In some embodiments, each heating unit includes a heating element and a switch for controlling the heating element. For example, the heating element may be a heating rod, and the switch may be a relay or a contactor.

[0038] In some embodiments, the at least two (i.e., M) heating units are in an operating state, wherein being in an operating state means that the switch controlling the heating element in the heating unit is in an on state, and being out of operation means that the switch controlling the heating element in the heating unit is in an off state.

[0039] In some embodiments, in 101, when the operating state of the heating unit is not changed, the main current value of the phase line is obtained. The operating state of the heating unit is not changed, which means that the on-off state of the switch remains unchanged (i.e., it remains in the on state) and the operating power of the heating element does not change. In addition, if the heating device also includes the aforementioned P heating units in a stopped state arranged in parallel on the branch of the same phase line, the operating state of the heating unit in the stopped state also needs to remain unchanged, that is, the on-off state of the switch remains unchanged (i.e., it remains in the off state). The main current value of the phase line can be obtained using a current sensor or a current transformer. For example, a current sensor or a current transformer can be set on the main line of the phase line to obtain the main current value. For details, please refer to the prior art and will not be repeated here.

[0040] The following uses the main current value of a phase line as an example to illustrate how to perform fault diagnosis. If the heating device includes multiple phase lines, the implementation method of fault diagnosis based on the main current value of each phase line is similar. For details, please refer to the embodiment of the second aspect described later, which will not be repeated here.

[0041] In some embodiments, before diagnosis, the acquired main current value can be optionally corrected and compensated to improve the reliability of fault diagnosis. When the heating element fails, compared with the case where the heating element has not failed, it can be regarded as an increase in the load in the circuit, resulting in a decrease in the main current value (for example, when the heating element fails, the branch where the heating element is located is in an open circuit state, thereby causing the load resistance in the circuit to increase, thereby causing the main current to decrease.). Therefore, when the main current value is not greater than the first current value, it is determined that the heating element in at least one heating unit has failed. It should be noted that after the acquired main current value is compensated and corrected, the compensated and corrected main current value can be compared with the first current value to determine whether the heating element has failed.

[0042] For example, the first current value may be a preset current value, or may be a main circuit current value previously detected when the heating element is not faulty, which will be described below with examples.

[0043] In some embodiments, the first current value is a preset current value, and the preset current value is set based on the total current A1 of all N heating elements in operation on the same phase line, or based on the total current A2 of N-1 heating elements among the N heating elements, where N is an integer not less than 2. For example, the first current value can be set to a value in the range of [A2, A1), and the embodiments of the present application are not limited thereto. Wherein, the total current A1 or A2 refers to the theoretical total current value when N or N-1 heating elements are not faulty and are in operation, and N is equal to M.

[0044] In some embodiments, the first current value may be a main current value previously detected when the heating element is not faulty, and the first current value represents the total current of all heating elements in operation (when none of them are faulty) on the same phase line; the method may also include: when it is determined that no heating unit is faulty, updating the acquired main current value to the first current value. For example, when it is determined that no heating unit is faulty, the first current value may be updated at predetermined intervals. Since the load of the heating element changes with the use time, the reliability of fault diagnosis may be further improved by regularly updating the first current value.

[0045] It can be seen from the above embodiments that the main current value can be compared with the first current value to determine whether a heating element has failed. When it is determined that a heating element has failed, the change in the main current value can also be used to determine which heating element has failed.

[0046] In some embodiments, in 102, the change value of the main current value caused by turning on and off the switch can be obtained, for example, one operating heating element is selected in turn, and while keeping the operating state of other heating elements unchanged (the on and off state of the switch remains unchanged and the operating power of the heating element whose corresponding switch is in the on state does not change), the first main current value when the heating element is in operation and the second main current value after the heating element stops operating are detected, and the change value of the main current value is determined according to the first main current value and the second main current value. For example, after the switch controlling the operation of the heating element is turned on, the first main current value is detected; after the switch controlling the operation of the heating element is turned off, the second main current value is detected.

[0047] In some embodiments, when the change value of the main current value is not greater than a preset change value, it is determined that the heating element controlled by the switch has failed. The preset change value is set based on the branch current A3 of the one heating element. For example, the preset change value can be a value in the range of [0, A3). For example, when the preset change value is 0, the change value of the main current value is 0, that is, the main current value does not change before and after the switch is turned on and off, which indicates that the heating element controlled by the switch has failed.

[0048] Figure 5 is a schematic diagram of an implementation method of operation 102, such as Figure 5 As shown, operation 102 includes:

[0049] 501, obtaining the current first trunk current value of the phase line;

[0050] 502, selecting the i-th heating element among the M-th heating elements in operation, when initially operating, i=1, where i is an integer greater than or equal to 1 and less than or equal to M;

[0051] 503, turning off the switch controlling the i-th heating element;

[0052] 504, obtaining a current second trunk current value of the phase line;

[0053] 505, judging whether the change value of the first trunk current value and the second trunk current value is not greater than the preset change value, if the judgment result is yes, executing 506, otherwise executing 507;

[0054] 506, determining that the i-th heating element is faulty;

[0055] 507, turn on the switch controlling the i-th heating element, so that i=i+1, and return to 501;

[0056] In some embodiments, after determining the failed heating element, the method may further include (not shown): controlling the failed heating element to stop running; starting a non-operating heating element that is not failed and is on the same phase line as the failed heating element. For example, the failed heating element may be controlled to stop running by disconnecting a switch, and in addition, the fault information may be reported to the background server; when the heating device includes at least two phase lines, if a heating element failure is detected in a branch of a phase line, the heating elements of other phase lines of the branch may be controlled (hereinafter, for convenience of description, the heating elements of the phase lines of the branch are described as follows). Figure 3 The heating elements of different phase lines in the box shown are called a group of heating elements) are also stopped to avoid multi-phase unbalanced operation. In addition, in order to ensure the heating power, the heating elements that are not running and have no faults and are on the same phase line as the faulty heating elements can be started to replace the faulty heating elements on the same phase line (or when the aforementioned group of heating elements is stopped, the heating elements of different phase lines in the same group as the replaced heating elements are also started at the same time, that is, a group of heating elements is started to replace the stopped group of heating elements). Figure 4 As shown, when the second group of U-phase heating elements fails, the heating elements on the second group of U-phase, V-phase, and W-phase can be stopped, and the fifth group of heating elements shown by the dotted line can be started (the heating elements on the U-phase, V-phase, and W-phase are all started).

[0057] In some embodiments, the method may further include: (not shown)

[0058] When the main current value is not less than the second current value, it is determined that a switch in at least one heating unit fails.

[0059] In some embodiments, the second current value is determined in a similar manner to the first current value and will not be described in detail here. The second current value is greater than or equal to the first current value. When the main current value is not less than the second current value, it is determined that a switch in at least one heating unit has failed. The switch failure may be a relay or contactor sticking, etc., and examples will not be given one by one here.

[0060] In some embodiments, after determining that a switch in at least one heating unit fails, the power switch of the heating device is turned off, and optionally, the fault information may be reported to a background server.

[0061] In some embodiments, when the heating time (operating time) of each heating element is unevenly distributed, it is easy to cause differences in the service life of each heating element. In order to avoid a higher failure rate of the heating elements, the method may also include: (not shown) counting the cumulative operating time of the at least two heating units arranged in parallel on the branches of the same phase line according to the main current value; adjusting the start-up order of each heating element according to the cumulative operating time.

[0062] For example, when the main current value does not satisfy the requirement of not being greater than the first current value and not being less than the second current value, it indicates that the heating elements and switches in the current heating device are not faulty, that is, the aforementioned M heating elements arranged in parallel on the same phase line are always in operation. Then, the operation time of each heating element is counted in real time. If a faulty heating element is found, the heating element is stopped. For the heating element, the operation time up to the detection time is used as the cumulative operation time. At the same time, the non-operating, non-faulty alternative heating element on the same phase line as the faulty heating element is turned on, and the cumulative operation time of the alternative heating element is accumulated from the detection time. In addition, for other heating elements that are not faulty and are always in operation, their operation time is accumulated continuously. When the heating device includes at least two phase lines, the cumulative operation time of the entire group of heating elements can be counted in units of the aforementioned group of heating elements. The specific statistical method will not be described in detail.

[0063] In some embodiments, the startup priority of each (or each group) of heating elements is dynamically adjusted according to the length of the accumulated running time, wherein the startup priority of the heating element (group) with a long accumulated running time is lowered, and the startup priority of the heating element (group) with a short accumulated running time is higher; the heating element (group) is started according to the startup priority. In this way, the life of multiple heating elements can be balanced, so as to extend the use and reduce the failure rate.

[0064] For example, Figure 4As shown, from the start time T1, the heating elements of the first to fourth groups are in operation. When the heating element of the second group U phase is detected to have a fault (T2 time), the heating elements of the second group U phase, V phase, and W phase are all stopped, and the heating elements of the fifth group shown by the dotted line are started (the heating elements of the U phase, V phase, and W phase are all started). Assuming that the current time is T3, the cumulative operation time of the first group, the third group, and the fourth group is T3-T1, the cumulative operation time of the second group is T2-T1, and the cumulative operation time of the fifth group is T3-T2. The startup priority of each group of heating elements is dynamically adjusted according to the length of the cumulative running time. For example, when T3-T2 is less than T2-T1 and less than T3-T1, the startup priority of the 5th group is adjusted to the highest, the startup priority of the 2nd group is the second highest, and the startup priority of the 1st, 3rd and 4th groups is the lowest. Then, at the next startup, when it is necessary to start 4 groups of heating elements, the 5th group and the 2nd group of heating elements will be started first, and 2 groups of heating elements will be randomly selected from the 1st, 3rd and 4th groups. The cumulative running time of the started heating elements will continue to be counted, and the startup priority of each heating element will be dynamically adjusted. Examples will not be given one by one here.

[0065] In some embodiments, the main circuit current value can also be used to calculate the power consumption of the heating device and the average power consumption of the heating element to facilitate management and maintenance by users and maintenance personnel.

[0066] Figure 6 Schematic diagram of the implementation of the fault determination method of this embodiment. Figure 6 As shown, for M heating elements in operation and arranged in parallel on a branch of a phase line, the method includes:

[0067] 601, obtaining a main circuit current value of the phase line when the operating state of the heating unit is not changed;

[0068] 602, determine whether the trunk current value is not greater than the first current value, if the determination result is yes, execute 603-606, otherwise execute 607;

[0069] 603, determining that a heating element in at least one heating unit fails;

[0070] 604, obtaining a change value of the trunk current value caused by turning on and off each switch, and determining a failed heating element (locating a fault point) according to the change value;

[0071] 605, controlling the failed heating element to stop operating;

[0072] 606, start a heating element that is not in operation and has no fault and is on the same phase line as the heating element with the fault;

[0073] 607, judging whether the trunk current value is not less than the second current value, if the judgment result is yes, executing 608-609, otherwise ending;

[0074] 608, determining that a switch in at least one heating unit is faulty;

[0075] 609, turn off the power switch of the heating device.

[0076] In some embodiments, the implementation of 604 can refer to Figure 5 The implementation methods of other operations are as described above and will not be repeated here.

[0077] It is worth noting that the above Figure 1 , Figure 5 , Figure 6 The embodiments of the present application are only schematically described, but the present application is not limited thereto. For example, the execution order of the various operations can be appropriately adjusted, and other operations can be added or some operations can be reduced. Those skilled in the art can make appropriate modifications based on the above content, and are not limited to the above appended Figure 1 , Figure 5 , Figure 6 Records

[0078] It can be seen from the above embodiments that whether a heating element is faulty can be determined based on the main current value, and the faulty heating element can be determined based on the change in the main current. In this way, fault diagnosis of multiple heating elements in a heating device can be achieved at low cost and with high reliability.

[0079] Embodiments of the second aspect

[0080] An embodiment of the second aspect of the present application provides a fault determination method for a heating device. In this embodiment, the working current of the heating device is a three-phase power supply current, and the heating device includes three phase lines. That is to say, when the heating device is working, each phase line of the three phase lines can include at least two (for example, M) heating units in parallel in the branch and in operation, and each heating unit includes a heating element and a switch for controlling the heating element.

[0081] In addition, as described in the embodiment of the first aspect, each of the three phase lines may also include P heating units in a stopped state (P is an integer greater than or equal to 0), and the P heating units are arranged in parallel with the aforementioned M heating units on the branch of the same phase line. That is to say, on each of the three phase lines, there are M+P heating units arranged in parallel on M+P branches.

[0082] In addition, as described in the embodiment of the first aspect, each branch may include one heating element or at least two (G, G is an integer greater than or equal to 1) heating elements connected in series, that is, the heating device may include 3×(M+P)×G heating elements, and each of the three phase lines is provided with (M+P)×G heating elements. In other words, the heating device includes M+P groups of heating elements, and a group of heating elements includes 3×G heating elements. Figure 3 As shown, the three phase lines are U phase, V phase and W phase. On each of the three phase lines, M operating heating elements are arranged in parallel on M branches (P=0), including M groups of heating elements, each group of heating units includes 3 heating elements, such as Figure 4 As shown, the three phase lines are U phase, V phase and W phase. On each of the three phase lines, there are M heating elements in operation and P heating elements that are stopped, which are arranged in parallel on M+P branches, including M+P groups of heating elements. Each phase line of each group of heating elements is connected in series with one heating element. Therefore, each group of heating elements includes 3 heating elements, which are not given examples one by one here.

[0083] In some embodiments, the heating elements on the three phase lines are connected in star or triangle. Figure 7 and Figure 8 They are schematic diagrams of the connection relationship of the heating elements on the three phase lines, such as Figure 7 As shown, the heating elements on the three phase lines are connected in star shape, such as Figure 8 As shown, the heating elements on the three phase lines are connected in a delta configuration.

[0084] Fig. 9 is a schematic diagram of the fault determination method of the heating device, such as Fig. 9 As shown, the method includes:

[0085] 901, when the operation state of the heating unit is not changed, obtaining the main current value of each phase line, and when the main current value is not greater than the first current value, determining that a heating element in at least one heating unit on the phase line where the main current is located fails;

[0086] 902, obtaining a change in the main current value caused by turning on and off the switch on the phase line where the heating element fails, and when the change in the main current value is not greater than a preset change value, determining that a branch where the heating element controlled by the switch is located fails.

[0087] In some embodiments, in the implementation of 901-902, it is necessary to judge the main current values ​​of the three phase lines respectively. The judgment method for the main current value of each phase line is the same. For details, please refer to 101-102 in the embodiment of the first aspect, and the repeated parts will not be repeated.

[0088] For example, in 902, when locating the fault point for each of the three phase lines, it is necessary to select a running heating element on the phase line where the heating element fault occurs in turn, and detect the first main current value of the heating element when it is running and the second main current value of the heating element after it stops running while keeping the operating status of other heating elements unchanged. The specific implementation method can refer to the embodiment of the first aspect and will not be repeated here.

[0089] In some embodiments, for each of the three phase lines, a respective first current value, a second current value and a preset current value are set. The method for determining the first current value, the second current value and the preset current value of each phase line can refer to the embodiment of the first aspect and will not be repeated here.

[0090] It is worth noting that the above Fig. 9 The embodiments of the present application are only schematically described, but the present application is not limited thereto. For example, the execution order of the various operations can be appropriately adjusted, and other operations can be added or some operations can be reduced. Those skilled in the art can make appropriate modifications based on the above content, and are not limited to the above appended Fig. 9 Records of.

[0091] It can be seen from the above embodiments that whether a heating element is faulty can be determined based on the main current value, and the faulty heating element can be determined based on the change in the main current. In this way, fault diagnosis of multiple heating elements in a heating device can be achieved at low cost and with high reliability.

[0092] Embodiments of the third aspect

[0093] The third aspect of the present application provides a device, Fig.10 is a schematic diagram of the fault determination device of the heating device, Fig.10 is a schematic diagram of a fault determination device according to an embodiment of the present application. Fig.10 As shown, the fault determination device 1000 of the embodiment of the present application may include: at least one interface ( Fig.101001), a processor (e.g., a central processing unit (CPU)) 1001, and a memory 1002; the memory 1002 is coupled to the processor 1001. The memory 1002 can store various data; in addition, the memory 1002 stores a program 1003 for determining a fault, and executes the program 1003 under the control of the processor 1001, and stores various preset thresholds and predetermined conditions.

[0094] In some embodiments, the processor 1001 can implement the fault determination method described in the embodiments of the first aspect or the second aspect. For example, the processor 1001 can be configured to: obtain the main current value of the phase line when the operating state of the heating unit is not changed, and determine that a heating element in at least one heating unit is faulty when the main current value is not greater than the first current value; obtain the change value of the main current value caused by turning on and off the switch, and determine that the heating element controlled by the switch is faulty when the change value of the main current value is not greater than a preset change value.

[0095] In some embodiments, the processor 1001 can also be configured to: obtain the main current value of each phase line when the operating state of the heating unit is not changed, and when the main current value is not greater than the first current value, determine that the heating element in at least one heating unit on the phase line where the main line is located is faulty; obtain the change value of the main current value caused by turning on and off the switch on the phase line where the heating element failure occurs, and when the change value of the main current value is not greater than the preset change value, determine that the branch where the heating element controlled by the switch is located is faulty.

[0096] It is worth noting that the fault determination device 1000 may also include a communication module 1004, or it is not necessary to include Fig.10 In addition, the fault determination device 1000 may also include Fig.10 For components not shown, reference may be made to related technologies and examples are not given one by one here. For example, the fault determination device 1000 may also include a current transformer for detecting a main current value. The processor 1001 is connected to the current transformer for obtaining the main current value.

[0097] In the embodiment of the present application, the processor 1001 is sometimes also referred to as a controller or an operation control, and may include a microprocessor or other processor device and / or logic device. The processor 1001 receives input and controls the operation of various components of the fault determination device 1000.

[0098] In the embodiment of the present application, the memory 1002 can be, for example, one or more of a cache, a flash memory, a hard drive, a removable medium, a volatile memory, a non-volatile memory or other suitable devices. Various information can be stored, and programs for executing relevant information can also be stored. And the processor 1001 can execute the program stored in the memory 1002 to implement information storage or processing, etc. The functions of other components are similar to those of the prior art and will not be repeated here. The various components of the fault determination device 1000 can be implemented by dedicated hardware, firmware, software or a combination thereof without departing from the scope of the present application.

[0099] For example, when the heating device is applied to an electric water heater, the processor 1001 can be configured separately from the processor of the electric water heater. For example, the processor 1001 can be configured as a chip connected to the processor of the electric water heater, and the two can control each other. Alternatively, the functions of the processor 1001 can be integrated into the processor of the electric water heater itself. The embodiments of the present application are not limited to this.

[0100] It can be seen from the above embodiments that whether a heating element is faulty can be determined based on the main current value, and the faulty heating element can be determined based on the change in the main current. In this way, fault diagnosis of multiple heating elements in a heating device can be achieved at low cost and with high reliability.

[0101] Embodiments of the fourth aspect

[0102] An embodiment of the fourth aspect of the present application provides an electric water heater. Fig.11 Schematic diagram of an electric water heater according to an embodiment of the present application. Fig.11 As shown, the electric water heater 1100 includes:

[0103] A heating device 1101, the heating device comprising at least two heating units arranged in parallel in a branch of the same phase line, the heating unit comprising a heating element and a switch for controlling the operation of the heating element;

[0104] Heating device fault determination device 1102;

[0105] Water channel assembly 1103, the heating element is used to heat the water in the water channel assembly.

[0106] In some embodiments, the working current of the heating device 1101 can be a single-phase power supply current or a three-phase power supply current. Its specific structure can refer to the first aspect or the second aspect. The implementation method of the fault determination device 1102 of the heating device can refer to the fault determination device 1000 of the third aspect, which will not be repeated here.

[0107] In some embodiments, the fault determination device 1102 of the heating device further includes: a current transformer for obtaining a main current value, the heating element is a heating rod, and the water circuit assembly 1103 includes an inner tank for storing water.

[0108] In some embodiments, the fault determination device 1102 can be configured separately from the processor of the electric water heater. For example, the fault determination device 1102 can be configured as a chip connected to the processor of the electric water heater, etc. The two can control each other, or the function of the fault determination device 1102 can be integrated into the processor of the electric water heater itself. The embodiments of the present application are not limited to this.

[0109] In some embodiments, the electric water heater can be a commercial high-power electric water heater. For example, the electric water heater can include at least two cascaded sub-electric water heaters, each of which is provided with a water circuit component and at least one heating unit in operation; and at least one heating unit in operation of each sub-electric water heater is connected in parallel on the same phase line.

[0110] Fig.12 This is a schematic diagram of the cascade electric water heater. Fig.12 As shown, the electric water heater 1200 includes at least two cascaded sub-electric water heaters 1201 and a heating device fault determination device 1202. In each sub-electric water heater 1201, a water circuit assembly 12011 and at least one heating unit 12012 in operation are provided, and at least one heating unit 12012 of each sub-electric water heater is connected in parallel on the same phase line. For example, when the working current is a single-phase power supply current, the electric water heater includes only one phase line, and the heating units in each sub-electric water heater are connected in parallel to the phase line; when the working current is a three-phase power supply current, the electric water heater includes three phase lines, and on each phase line of the three phase lines, at least one heating unit in each sub-electric water heater is connected in parallel to the phase line; in other words, each sub-electric water heater includes at least one group of heating elements.

[0111] In addition, as described in the embodiment of the first aspect, on each of the three phase lines, each sub-electric water heater may include P heating units (P is an integer greater than or equal to 0) in a stopped state, and the P heating units are arranged in parallel with the at least one heating unit on the branch of the same phase line. Each sub-electric water heater may include one heating element or at least two (G, G is an integer greater than or equal to 1) heating elements connected in series on each branch, such as Figure 3 As shown, the M groups of heating elements in operation can be distributed in each sub-electric water heater 1201, so that each sub-electric water heater 1201 includes at least one group of heating elements in operation, such as Figure 4As shown, the M group of heating elements in operation can be distributed in each sub-electric water heater 1201, so that each sub-electric water heater 1201 includes at least one group of heating elements in operation. In addition, the P group of heating elements in the stopped operation state can also be distributed in each sub-electric water heater 1201, and each sub-electric water heater 1201 may or may not include the aforementioned heating elements in the stopped operation state.

[0112] In some embodiments, the fault determination device 1202 can be configured separately from the processor of each sub-electric water heater. For example, the fault determination device 1202 can be configured as a chip connected to the processor of each sub-electric water heater, etc. The two can control each other. Alternatively, the function of the fault determination device 1202 can be integrated into the processor of one of the sub-electric water heaters (for example, the first sub-electric water heater). The embodiments of the present application are not limited to this.

[0113] In some embodiments, the fault determination device is configured to execute the fault determination method in the first or second aspect embodiment. For details, please refer to the first or second aspect embodiment, and the repeated parts will not be repeated.

[0114] It is worth noting that the electric water heater 1100 or 1200 may also include Fig.11 or Fig.12 For components not shown in the figure, reference can be made to the relevant technology and no further examples are given here.

[0115] It can be seen from the above embodiments that whether a heating element is faulty can be determined based on the main current value, and the faulty heating element can be determined based on the change in the main current. In this way, fault diagnosis of multiple heating elements in a heating device can be achieved at low cost and with high reliability.

[0116] An embodiment of the present application also provides a computer program, wherein when the program is executed in a fault determination device or an electric water heater, the program causes the main controller to execute the fault determination method described in the embodiment of the first or second aspect.

[0117] An embodiment of the present application also provides a storage medium storing a computer program, wherein the computer program enables a fault determination device or an electric water heater to execute the fault determination method described in the embodiment of the first or second aspect.

[0118] The data transmission device described in the embodiments of the present application may be directly embodied as hardware, a software module executed by a processor, or a combination of the two. For example, one or more of the functional block diagrams shown in the figure and / or one or more combinations of the functional block diagrams may correspond to various software modules of the computer program flow or to various hardware modules. These software modules may correspond to Figure 1 , Figure 5, Figure 6 , Fig. 9 These hardware modules can be implemented by solidifying these software modules using, for example, a field programmable gate array (FPGA).

[0119] The software module may be located in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM or any other form of storage medium known in the art. A storage medium may be coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium; or the storage medium may be an integral part of the processor. The processor and the storage medium may be located in an ASIC. The software module may be stored in a memory of an information processing system or in a memory card that can be inserted into the information processing system.

[0120] For one or more of the functional block diagrams described in the figure and / or one or more combinations of the functional block diagrams, it can be implemented as a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, or any appropriate combination thereof for performing the functions described in the present application. For one or more of the functional block diagrams described in the figure and / or one or more combinations of the functional block diagrams, it can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in communication with a DSP, or any other such configuration.

[0121] The present application is described above in conjunction with specific implementation methods, but it should be clear to those skilled in the art that these descriptions are exemplary and are not intended to limit the scope of protection of the present application. Those skilled in the art can make various modifications and variations to the present application based on the spirit and principles of the present application, and these modifications and variations are also within the scope of the present application.

Claims

1. A method for determining a fault of a heating device, characterized in that: When the heating device comprises at least two heating units in operation and arranged in parallel on a branch of the same phase line, and the heating unit comprises a heating element and a switch for controlling the heating element, the method comprises: When the operation state of the heating unit is not changed, obtaining the main current value of the phase line, and determining that a heating element in at least one heating unit fails when the main current value is not greater than a first current value; A change value of the main current value caused by turning the switch on and off is obtained, and when the change value of the main current value is not greater than a preset change value, it is determined that a heating element controlled by the switch fails.

2. The method according to claim 1, characterized in that The first current value is a preset current value, and the preset current value is set based on the total current of all N heating elements in operation on the same phase line, or based on the total current of N-1 heating elements among the N heating elements, wherein N is an integer not less than 2.

3. The method according to claim 1, characterized in that The method further comprises: When it is determined that no heating unit fails, the acquired main current value is updated to the first current value.

4. The method according to claim 1, characterized in that: The step of obtaining a change in the trunk current value caused by turning on and off the switch comprises: A running heating element is selected in turn, and while keeping the running states of other heating elements unchanged, a first main current value of the one heating element when it is running and a second main current value of the one heating element after it stops running are detected.

5. The method according to claim 4, characterized in that After the switch controlling the operation of the one heating element is turned on, the first main current value is detected; after the switch controlling the operation of the one heating element is turned off, the second main current value is detected.

6. The method according to claim 1, characterized in that The method further comprises: Control the failed heating element to stop operating; Start the non-operating, non-faulty heating element that is on the same phase as the faulty heating element.

7. The method according to claim 1, characterized in that The method further comprises: When the main current value is not less than the second current value, it is determined that a switch in at least one heating unit fails.

8. The method according to claim 7, characterized in that The method further includes disconnecting a power switch of the heating device after determining that a switch in at least one heating unit fails.

9. The method according to claim 1, characterized in that: The method further comprises: Counting the accumulated operation time of the at least two heating units connected in parallel on the branches of the same phase line according to the main current value; The activation sequence of each heating element is adjusted according to the accumulated operating time.

10. The method according to claim 9, characterized in that The step of adjusting the start-up sequence of each heating element according to the accumulated running time comprises: Dynamically adjust the startup priority of each heating element according to the length of the accumulated running time, wherein the startup priority of the heating element with a long accumulated running time is lowered, and the startup priority of the heating element with a short accumulated running time is high; The heating elements are activated according to the activation priorities.

11. A method for determining a fault of a heating device, characterized in that: When the working current of the heating device is a three-phase power supply current, and each phase line of the three phase lines includes at least two heating units in operation and arranged in parallel on the branch, and the heating unit includes a heating element and a switch for controlling the heating element, the method includes: When the operation state of the heating unit is not changed, obtaining the main current value of each phase line, and when the main current value is not greater than the first current value, determining that a heating element in at least one heating unit on the phase line where the main current is located fails; The change value of the main current value caused by turning on and off the switch on the phase line where the heating element fails is obtained. When the change value of the main current value is not greater than a preset change value, it is determined that the branch where the heating element controlled by the switch is located fails.

12. The method according to claim 11, characterized in that The step of obtaining a change value of the main circuit current value caused by turning on and off the switch on the phase line where the heating element failure occurs comprises: A running heating element is selected in turn on the phase line where a heating element failure occurs, and a first main circuit current value when the heating element is running and a second main circuit current value after the heating element stops running are detected while keeping the operating states of other heating elements unchanged.

13. The method according to claim 12, characterized in that After the switch controlling the operation of the one heating element is turned on, the first main current value is detected, and after the switch controlling the operation of the one heating element is turned off, the second main current value is detected.

14. The method according to claim 11, characterized in that The first current value is a preset current value, and the preset current value is set based on the total current of all N heating elements in operation on the same phase line, or based on the total current of N-1 heating elements among the N heating elements, where N is not less than 2.

15. The method according to claim 11, characterized in that The method further comprises: When it is determined that no heating unit fails, the main current value of each phase line is obtained and updated to the first current value corresponding to each phase line. 16 . A failure determination device for a heating device, comprising a processor, wherein the processor is configured to execute the failure determination method for a heating device according to claim 1 .

17. An electric water heater, characterized in that: The electric water heater comprises: A heating device, the heating device comprising at least two heating units arranged in parallel on a branch of the same phase line, the heating unit comprising a heating element and a switch for controlling the operation of the heating element; A fault determination device for the heating device according to claim 16; The water channel assembly is used for heating the water in the water channel assembly.

18. The electric water heater according to claim 17, wherein the working current of the heating device is a three-phase power supply current, and each of the three phase lines includes at least two heating units arranged in parallel in a branch, and the heating elements on the three phase lines are connected in a star shape or a triangle shape.

19. The electric water heater according to claim 17, characterized in that: The electric water heater comprises at least two cascaded sub-electric water heaters, each of which is provided with a water circuit assembly and at least one heating unit; and at least one heating unit of each sub-electric water heater is connected in parallel on the same phase line.

20. The electric water heater according to any one of claims 17 to 19, characterized in that: The fault determination device of the heating device further comprises: a current transformer for obtaining a main circuit current value; the heating element is a heating rod; and the water circuit assembly comprises an inner tank for storing water.

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