Control device for correcting flow through temperature feedback

Abstract

The utility model discloses a control device for correcting flow by utilizing temperature feedback, and relates to the technical field of instant heating type water heating products. A detection flow signal of the flow meter and a detection temperature of the water inlet temperature sensor are combined with a set value of a target temperature to serve as a primary heating power output source; according to the difference value between the detected temperature of the outlet water temperature sensor and the target temperature, the actual flow value is reversely deduced, the reversely deduced flow value is used for replacing the detected flow value of the flow meter in an overlapping mode, the logic relation between the signal of the flow meter and the flow is corrected, and therefore the flow correction of the waterway system is achieved. The problem that flow detection is not accurate due to deviation of the flow meter is solved, the water outlet temperature can be more accurately and rapidly controlled, and the heating power can be more accurately controlled.

Description

Technical Field

[0001] The utility model relates to the technical field of instant water heating products, in particular to a control device for correcting flow rate by using temperature feedback. Background Art

[0002] In recent years, with the technological progress of household appliances and the improvement of people's living standards, the demand for water heating in daily life has increased, and a series of products with water heating functions have emerged, such as various types of water heaters, small kitchen appliances, smart toilets, etc. At present, these water heating products have changed from traditional water tank heating and heat storage type to tankless instant heating type. Due to its own principle, the instant water heating device requires its heater to have a higher heating power to achieve the demand for instant heating of cold water, which puts forward higher requirements on the control of flow and temperature.

[0003] In the prior art, in the field of instant water heating, for water systems that need to control water flow and water temperature, a flow controller is usually set to control the required water flow, a flow meter or a flow meter equivalent device (such as a liquid level sensor in a water tank to convert the flow rate) is set to detect the water flow, an inlet water temperature sensor is set to detect the inlet water temperature, and an outlet water temperature sensor is set to detect the outlet water temperature. The controller performs calculations based on the flow information, the inlet water temperature information, and the target water temperature information, and gives a power control signal for the water heater to control the heating power of the water heater so that the water is heated to the target temperature; and the power of the heater can be controlled based on the feedback signal of the outlet water temperature sensor, and it is continuously iterated so that the water temperature reaches the target value.

[0004] At present, in this control mode, the flow controller needs to rely on the feedback information of the flow meter or flow meter equivalent device to control the water flow. When the flow meter or flow meter equivalent device produces errors due to its own manufacturing, assembly, hardware, and software, the information of the detected water flow will deviate, and this deviation will lead to inaccurate flow; further, the inaccurate detection of the actual flow will cause the controller to inaccurately control the heating power of the heater, output inaccurate control heating signals, and cause the water temperature to deviate from the target temperature; further, although the actual temperature can be brought closer to the target temperature through temperature feedback at a later stage, the process of continuously iterating and correcting the heating power will consume a lot of time, and the deviation of the flow leads to changes in the amount of heated water, which leads to a power offset, thereby causing the actual power of the whole machine to deviate from the specification. Utility Model Content

[0005] In order to solve the technical problems existing in the background technology, a control device for correcting the water flow rate by using water temperature feedback is provided. On the basis of the logic of normal water flow and water temperature control, the outlet water temperature feedback and the correction flow information are realized by adding a power supply voltage detection module and additional operation logic, thereby avoiding the problem of inaccurate flow detection caused by the deviation of the flow meter or the flow meter equivalent device itself, and being able to control the outlet water temperature more accurately and quickly, and to control the heating power more accurately.

[0006] The utility model proposes a control device for correcting flow rate by using temperature feedback, comprising a controller, a flow meter, a heater, a flow regulating valve, a nozzle, a water inlet temperature sensor, a water outlet temperature sensor, and a voltage detection module;

[0007] The flow meter, heater, flow regulating valve and nozzle are sequentially arranged between the water inlet and the water outlet of the water channel.

[0008] The water inlet temperature sensor is arranged between the flow meter and the heater;

[0009] The outlet water temperature sensor is arranged between the heater and the flow regulating valve;

[0010] The flow meter, heater, flow regulating valve, water inlet temperature sensor, water outlet temperature sensor and voltage detection module are all electrically connected to the controller.

[0011] Preferably, the input and output signals to the controller include a pulse signal output by a flow meter, a heating signal received by a heater, a driving signal received by a flow control valve, an inlet water temperature signal detected by an inlet water temperature sensor, an outlet water temperature signal detected by an outlet water temperature sensor, and a voltage signal detected by a voltage detection module;

[0012] The pulse signal, heating signal, drive signal, water inlet temperature signal, and water outlet temperature signal are all connected to the controller;

[0013] The voltage signal is connected to a controller.

[0014] Preferably, the controller is internally provided with voltage-power conversion logic and flow detection logic;

[0015] The flow detection logic includes a first flow detection logic and a second flow detection logic;

[0016] The first flow detection logic converts the pulse frequency of the flow meter into the detected flow;

[0017] The second flow rate detection logic reversely infers the actual flow rate value according to the difference between the detected temperature of the outlet water temperature sensor and the target temperature according to the heating power.

[0018] In the present invention, the control device for correcting flow rate by using temperature feedback has the following beneficial technical effects:

[0019] Through the temperature control characteristics of the water circuit itself, the flow meter's detected flow signal and the detected temperature of the water inlet temperature sensor are combined with the target temperature setting value as the initial heating power output source; then the actual flow value is reversed according to the difference between the detected temperature of the water outlet temperature sensor and the target temperature, and the reversed flow value is used to iteratively replace the flow meter's detected flow value, and the logical relationship between the flow meter signal and the flow is corrected, thereby realizing the correction of the flow of the water circuit system. The problem of inaccurate flow detection caused by the deviation of the flow meter itself is avoided, and the outlet water temperature can be controlled more accurately and quickly, and the heating power can be controlled more accurately.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the front view of the structure of the utility model;

[0022] Figure 2 This is the voltage-power conversion logic diagram of the utility model;

[0023] Figure 3 This is a flow detection logic schematic diagram of the utility model.

[0024] In the figure, 1. controller; 2. flow meter; 3. heater; 4. flow control valve; 5. nozzle; 6. water inlet temperature sensor; 7. water outlet temperature sensor; 8. voltage detection module; 101. drive signal; 102. heating signal; 201. pulse signal; 601. water inlet temperature signal; 701. water outlet temperature signal; 801. voltage signal; 11. voltage-power conversion logic; 12. flow detection logic. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar symbols throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0026] like Figure 1 A control device for correcting flow rate by temperature feedback is shown, comprising a controller 1, a flow meter 2, a heater 3, a flow regulating valve 4, a nozzle 5, a water inlet temperature sensor 6, a water outlet temperature sensor 7, and a voltage detection module 8. The voltage detection module 8 is a voltage detector or a voltage detector in the prior art;

[0027] The flow meter 2, the heater 3, the flow regulating valve 4 and the nozzle 5 are sequentially arranged between the water inlet and the water outlet of the water channel.

[0028] The water inlet temperature sensor 6 is arranged between the flow meter 2 and the heater 3 to minimize the influence of external factors on the water flow and detect the water inlet temperature closest to the point before heating;

[0029] The outlet water temperature sensor 7 is arranged between the heater 3 and the flow regulating valve 4 to minimize the influence of external factors on the water flow and detect the outlet water temperature closest to the heating;

[0030] A flow regulating valve 4 is arranged in front of the nozzle 5, and the flow regulating valve 4 is used to control the flow rate of the water flow;

[0031] The flow meter 2 , the heater 3 , the flow regulating valve 4 , the water inlet temperature sensor 6 , the water outlet temperature sensor 7 , and the voltage detection module 8 are all electrically connected to the controller 1 .

[0032] The signals of the flow meter 2, the water inlet temperature sensor 6, the water outlet temperature sensor 7, and the voltage detection module 8 are input to the controller 1, and the controller 1 performs unified calculations;

[0033] The controller 1 outputs control signals to the heater 3 and the flow regulating valve 4 to control the heating power of the heater 3 and the flow regulation of the flow regulating valve 4 .

[0034] The input and output signals to the controller 1 are: the pulse signal 201 output by the flow meter 2, the heating signal 102 received by the heater 3, the driving signal 101 received by the flow control valve 4, the inlet water temperature signal 601 detected by the inlet water temperature sensor 6, the outlet water temperature signal 701 detected by the outlet water temperature sensor 7, and the voltage signal 801 detected by the voltage detection module 8;

[0035] The pulse signal 201, the heating signal 102, the driving signal 101, the water inlet temperature signal 601, and the water outlet temperature signal 701 are all connected to the controller 1;

[0036] The voltage signal 801 is connected to the controller 1 .

[0037] Considering the instability of voltage in actual use, a voltage detection module 8 is provided at the front end of the controller 1. The voltage detection module 8 can adjust the control parameters according to the detected voltage value and the target power value of the control;

[0038] The controller 1 is internally provided with a voltage-power conversion logic 11 and a flow detection logic 12. The flow detection logic 12 includes a first flow detection logic and a second flow detection logic. The first flow detection logic converts the pulse frequency of the flow meter into a detected flow; the second flow detection logic reversely infers the actual flow value according to the heating power based on the difference between the detected temperature of the water outlet temperature sensor and the target temperature.

[0039] When the device uses the water heating function, the water flows from the water inlet through the flow meter 2, the heater 3, the flow regulating valve 4, and the nozzle 5 in sequence, and then flows out from the water outlet. The flow regulating valve 4 performs preliminary flow adjustment according to the user's flow setting; the controller 1 performs calculations based on the pulse signal 201 detected by the flow meter 2, the water inlet temperature signal 601 detected by the water inlet temperature sensor 6, and the user's water temperature setting, and outputs a heating signal 102 to the heater 3; the water outlet temperature signal 701 detected by the water outlet temperature sensor 7 is fed back to the controller 1, and the controller 1 compares and calculates the theoretical temperature and the detected temperature of the water outlet temperature sensor 7, and calculates the actual flow through the water temperature reverse calculation formula ⑥q=P / (λ·c·Δt·ρ)·60·10^6.

[0040] Working principle:

[0041] When the device uses the water heating function, the water flows from the water inlet through the flow meter 2, the heater 3, the flow regulating valve 4, the nozzle 5, and then flows out from the water outlet;

[0042] The flow regulating valve 4 performs preliminary flow regulation according to the user's usage flow setting;

[0043] The controller 1 performs calculations based on the pulse signal 201 detected by the flow meter 2, the water inlet temperature signal 601 detected by the water inlet temperature sensor 6 and the user's water temperature setting, and outputs a heating signal 102 to the heater 3;

[0044] The outlet water temperature signal 701 detected by the outlet water temperature sensor 7 is fed back to the controller 1, and the controller 1 compares the theoretical temperature and the temperature detected by the outlet water temperature sensor 7 to calculate the actual flow rate.

[0045] The basic supporting theory is:

[0046] ① Heat energy formula Q = c·m·Δt. Where: heat Q: joule (J), specific heat c: joule / kg ℃

[0047] (J / kg℃), mass m: kilogram (kg), temperature difference △t: degree Celsius (℃);

[0048] ② Density formula: ρ = m / V. Where: density ρ: kilograms / cubic meter (kg / m^3), mass m:

[0049] Kilogram (kg), volume V: cubic meter (m^3)

[0050] ③ Heat-power formula Q = P·T. Where: heat Q: joule (J), power P: watt (W), time T: second (s)

[0051] ④ In addition, water flow q = V / T·60·10^6. Where: water flow q: milliliters / minute (ml / min),

[0052] Volume V: cubic meter (m^3), time T: second (s);

[0053] Combining ①②③④, we can get the formula ⑤ for inferring water flow rate based on water temperature: water flow rate q = P / (c·Δt·ρ)·60·10^6. Among them: water flow rate q: ml / min, specific heat capacity c:

[0054] Joule / kilogram °C (J / kg °C), temperature difference △t: degrees Celsius (°C), density ρ: kilogram / cubic meter (kg / m^3).

[0055] Usually, in the actual whole system, water heating will have energy loss and conduction heat dissipation due to the influence of water channel structure and use environment. The energy cannot be completely converted into thermal energy in the water, so a coefficient λ will be added to the thermal energy formula ①, that is, Q=λ·c·m·Δt. The coefficient λ depends on the composition of the water channel system of the specific product and is generally obtained through experiments.

[0056] In this way, the formula for inferring water flow from water temperature evolves into formula ⑥q=P / (λ·c·Δt·ρ)·60·10^6.

[0057] like Figure 2 The voltage-power conversion logic diagram shown in Figure 2 Middle: high voltage U1; low voltage U2; short on-time x1; long on-time x2.

[0058] The voltage used by users usually fluctuates. The voltage detection module 8 detects the voltage signal 801 and determines whether the voltage meets the high voltage U1 or the low voltage U2. The controller 1 selects the short on time x1 or the long on time x2 of the corresponding heating time according to the result of the voltage judgment, thereby controlling the heating power of the heater 3.

[0059] like Figure 3The flow detection logic diagram shown is initially executed according to the first flow logic, and the flow rate a is calculated based on the pulse frequency of the pulse signal 201 output by the flow meter 2. After the controller 1 controls the heater 3 for heating, the controller 1 reversely calculates the actual water flow rate b based on the outlet water temperature signal 701 detected by the outlet water temperature sensor 7. The flow rate b is used instead of the flow rate a to control the water channel, and it is iteratively corresponded to the pulse signal 201 of the flow meter 2, thereby realizing the correction of the flow rate.

[0060] Synchronously, the controller 1 outputs a drive signal 101 to the flow regulating valve 4 according to the correct flow b, driving the flow regulating valve 4 to adjust to the correct user-set flow value; the controller 1 detects the voltage signal 801 according to the correct flow b in combination with the voltage detection module 8, selects the corresponding voltage-power conversion logic, and outputs the correct heating signal 102 to the heater 3 to achieve the target temperature value.

[0061] This design is applied to the field of instant water heating products.

[0062] Through the temperature control characteristics of the water path itself, an initial control logic is applied, using the flow rate signal detected by the flow meter 2 and the temperature detected by the water inlet temperature sensor 6 combined with the set value of the target temperature as the initial heating power output source;

[0063] Then, the actual flow value is inferred according to the difference between the detected temperature of the outlet water temperature sensor 7 and the target temperature, and the detected flow value of the flow meter 2 is iteratively replaced with the inferred flow value to correct the logical relationship between the signal of the flow meter 2 and the flow, thereby realizing the correction of the flow of the water system.

[0064] The control method and implementation mode of the water flow rate correction by water temperature feedback of the present design, through the temperature control characteristics of the water circuit itself, uses the flow rate signal detected by the flow meter 2 and the temperature detected by the water inlet temperature sensor 6 combined with the target temperature setting value as the initial heating power output source; then the actual flow value is reversed according to the difference between the temperature detected by the water outlet temperature sensor 7 and the target temperature, and the reversed flow value is used to iteratively replace the flow rate value detected by the flow meter 2, and the logical relationship between the signal of the flow meter 2 and the flow rate is corrected, thereby realizing the correction of the flow rate of the water circuit system. The problem of inaccurate flow detection caused by the deviation of the flow meter 2 itself is avoided, and the outlet water temperature can be controlled more accurately and quickly, and the heating power can be controlled more accurately.

[0065] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0066] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0067] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0068] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0069] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0070] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A control device for correcting flow rate using temperature feedback, characterized in that: It comprises a controller (1), a flow meter (2), a heater (3), a flow regulating valve (4), a nozzle (5), a water inlet temperature sensor (6), a water outlet temperature sensor (7), and a voltage detection module (8); The flow meter (2), the heater (3), the flow regulating valve (4) and the nozzle (5) are sequentially arranged between the water inlet and the water outlet of the water channel. The water inlet temperature sensor (6) is arranged between the flow meter (2) and the heater (3); The water outlet temperature sensor (7) is arranged between the heater (3) and the flow regulating valve (4); The flow meter (2), the heater (3), the flow regulating valve (4), the water inlet temperature sensor (6), the water outlet temperature sensor (7), and the voltage detection module (8) are all electrically connected to the controller (1).

2. The control device for correcting flow rate by temperature feedback according to claim 1, characterized in that: The input and output signals of the controller (1) include a pulse signal (201) output by the flow meter (2), a heating signal (102) received by the heater (3), a drive signal (101) received by the flow control valve (4), an inlet water temperature signal (601) detected by the inlet water temperature sensor (6), an outlet water temperature signal (701) detected by the outlet water temperature sensor (7), and a voltage signal (801) detected by the voltage detection module (8); The pulse signal (201), the heating signal (102), the drive signal (101), the water inlet temperature signal (601), and the water outlet temperature signal (701) are all connected to the controller (1); The voltage signal (801) is connected to the controller (1).

3. The control device for correcting flow rate by temperature feedback according to claim 1, characterized in that: The controller (1) is internally provided with voltage-power conversion logic (11) and flow detection logic (12); The flow detection logic (12) includes a first flow detection logic (12) and a second flow detection logic (12); The first flow detection logic (12) converts the pulse frequency of the flow meter (2) into a detected flow rate; The second flow detection logic (12) reversely infers the actual flow value based on the difference between the detected temperature of the water outlet temperature sensor (7) and the target temperature according to the heating power.

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