Temperature rise control method adopting microswitch to replace water flow sensor

Abstract

The invention discloses a temperature rise control method adopting a microswitch to replace a water flow sensor. The temperature rise control method comprises the following steps that the microswitch detects that water flow passes through, heating is conducted for a period of time with the initial power P0, the temperature is made to rise from T0 to T1, the pre-judged water flow q0 in a pipeline is calculated according to a formula, and then the first heating power P1 is calculated according to the set temperature T and the water flow q0; the water body is heated at the first heating power P1, the power is finely adjusted through a PID algorithm, after the time delta t, the water temperature constantly reaches T < set >, at the moment, the second power P < constant > is recorded, the temperature rise rate v is calculated, and then the temperature rise rate v is compared with the standard temperature rise rate v < standard >; if the deviation between the temperature rise rate and the standard rate is within + / -10% and the output power is Pconstant, the PID algorithm is used for fine adjustment to control the heating power, so that the water temperature is constant to be Tconstant, the temperature rise rate is calculated and compared with the standard rate every time interval t1, and the previous step is returned to judge whether the deviation between the temperature rise rate and the standard rate is within + / -10%; if the temperature rise rate and the standard rate are not within the deviation range of + / -10%, constant heating is conducted for a period of time with P, the temperature rise delta T3 is calculated, qA is calculated, PA and output power PA are calculated according to qA, and the heating power is finely adjusted and controlled through a PID algorithm. The accuracy of water flow detection is not affected by incrustation, temperature rise is regulated and controlled according to the measured water flow, the constant temperature speed is high, better use experience is provided for a user, and the service life of a product is also prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of water heaters, and in particular to a method for controlling temperature rise by using a micro switch instead of a water flow sensor. Background Art

[0002] At present, instant water heaters on the market usually use water flow sensors to detect water flow. However, after long-term use of the instant water heater, scale will adhere to the impeller of the water flow sensor, causing the impeller's rotation speed to decrease, resulting in a low measured water flow, and thus the calculated power will also be low, ultimately resulting in a slow constant temperature speed, affecting the user experience. Summary of the invention

[0003] The purpose of the present invention is to provide a method for controlling temperature rise by using a micro switch instead of a water flow sensor. The method uses a micro switch combined with a PD algorithm to determine whether water is flowing and detect the water flow rate, thereby solving the problem that scale affects the accuracy of water flow detection due to long-term use, thereby overcoming the shortcomings of the prior art.

[0004] The present invention provides a method for controlling temperature rise by using a micro switch instead of a water flow sensor through the following technical scheme, which is characterized by comprising the following steps:

[0005] S1, the micro switch detects the water flow, and uses the initial power P0 to heat for a period of time, so that the temperature rises from T0 to T1, and the predicted water flow q0 in the pipeline is calculated according to the formula:

[0006] ΔT0=T1-T0 (1)

[0007]

[0008] Then press the set temperature T 设 And water flow q0 calculate the first heating power P1:

[0009] ΔT1=T 设 -T 环 (3)

[0010]

[0011] In formula (1), (2), and (3), C is the specific heat capacity of water, T 环 is the ambient temperature, k is the conversion efficiency calibration coefficient, and the range of k is 70%-100%;

[0012] S2, heating the water body with the first heating power P1 and fine-tuning the power through the PID algorithm so that after a time Δt, the water temperature reaches a constant T 设 , at this time record the second power P 恒 , calculate the temperature rise rate v, and then compare it with the standard temperature rise rate v 标contrast:

[0013] v=ΔT1 / Δt (5)

[0014] S3. If the temperature rise rate is within ±10% deviation from the standard rate, execute step S4; if the temperature rise rate is not within ±10% deviation from the standard rate, execute step S5.

[0015] S4, output power P 恒 PID algorithm is used to fine-tune the heating power to keep the water temperature constant at T 恒 , at each time interval t1, calculate the temperature rise rate and compare it with the standard rate, and return to step S3;

[0016] S5, P 恒 After heating for a period of time, calculate the temperature rise ΔT3 and calculate q A , according to q A Calculate P A , output power P A , the heating power is fine-tuned and controlled by the PID algorithm.

[0017] ΔT A =T 设 -T 环 (6)

[0018]

[0019] Furthermore, the standard deviation is determined by a standard deviation table prepared by a laboratory, in which the water flow rate is divided into several levels, each level corresponding to a standard temperature rise rate.

[0020] Furthermore, in step S1, heating is performed with initial power P0 for a period of time, and the duration of this period of time is 5 seconds.

[0021] Furthermore, in step S4, the interval time t1 is 2s.

[0022] The present invention has the following beneficial effects: The present invention provides a method for controlling temperature rise by using a micro switch instead of a water flow sensor, which uses a micro switch and combines a software algorithm to determine whether water is flowing and detect the water flow, and adjusts the output power of the instant heating membrane according to the water flow. The accuracy of the water flow detection of the present invention will not be affected by scale, the constant temperature speed is fast, the user is given a better use experience, and the service life of the product is also extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention provides a flow chart of a method for controlling temperature rise by using a micro switch instead of a water flow sensor. DETAILED DESCRIPTION

[0024] The technical solution of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0025] The components of the embodiments of the present application generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed, but merely represents the selected embodiments of the present application.

[0026] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of this application.

[0027] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0028] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0029] Refer to the following Figure 1 A method for controlling temperature rise using a micro switch instead of a water flow sensor according to some embodiments of the present application is described, comprising the following steps:

[0030] S1, water flows through, the valve opens, the micro switch is pressed, the water flow signal is transmitted to the software, and the initial power P0 = 500W is used for heating for 5s, so that the temperature rises from T0 to T1. The predicted water flow q0 in the pipeline is calculated according to formula (2):

[0031] ΔT0=T1-T0 (1)

[0032]

[0033] Then press the set temperature T设 And water flow q0 calculate the first heating power P1:

[0034] ΔT1=T 设 -T 环 (3)

[0035]

[0036] In formula (3), T 环 is the ambient temperature, in °C;

[0037] S2, heating the water body with the first heating power P1 and fine-tuning the power through the PID algorithm so that after a time Δt, the water temperature reaches a constant T 设 , at this time record the second power P 恒， Calculate the temperature rise rate v and compare it with the standard temperature rise rate v 标 contrast:

[0038] v=ΔT1 / Δt (5)

[0039] S3, if the temperature rise rate is within ±10% of the standard rate, execute step S4; if the temperature rise rate is not within ±10% of the standard rate, execute step S5. The standard deviation is determined by the standard deviation table developed by the laboratory, which divides the water flow into several levels, each level corresponding to a standard temperature rise rate.

[0040] S4, output power P 恒 PID algorithm is used to fine-tune the heating power to keep the water temperature constant at T 恒 , every 5s, calculate the temperature rise rate and compare it with the standard rate, and return to step S3;

[0041] S5, P 恒 After heating for a period of time, calculate the temperature rise ΔT3 and calculate q A , according to q A Calculate P A , output power P A , the heating power is fine-tuned and controlled by the PID algorithm.

[0042] ΔT A =T 设 -T 环 (6)

[0043]

[0044]

[0045] In formulas (1)(2)(3)(4)(5)(6)(7)(8), C is the specific heat capacity of water 4.2×10 38J / (kg·℃); k is the conversion efficiency calibration coefficient, and the range of k is 70%-100%; P is the output power of the instant thermal film, in W; ΔT is the temperature rise, in ℃; q is the water flow rate, in mL / min.

[0046] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for controlling temperature rise by using a micro switch instead of a water flow sensor, characterized in that: The following steps are involved: S1, the micro switch detects the water flow, and uses the initial power P0 to heat for a period of time, so that the temperature rises from T0 to T1, and the predicted water flow q0 in the pipeline is calculated according to the formula: ΔT0=T1-T0 (1) Then press the set temperature T 设 And water flow q0 calculate the first heating power P1: ΔT1=T 设 -T 环 (3) In formula (1), (2), (3), and (4), C is the specific heat capacity of water, T 环 is the ambient temperature, k is the conversion efficiency calibration coefficient, and the range of k is 70%-100%; S2, heating the water body with the first heating power P1 and fine-tuning the power through the PID algorithm so that after a time Δt, the water temperature reaches a constant T 设 , at this time record the second power P 恒 , calculate the temperature rise rate v, and then compare it with the standard temperature rise rate v 标 contrast: v=ΔT1 / Δt(5) S3. If the temperature rise rate is within ±10% deviation from the standard rate, execute step S4; if the temperature rise rate is not within ±10% deviation from the standard rate, execute step S5. S4, output power P 恒， The PID algorithm is used to fine-tune the heating power to keep the water temperature constant at T 恒 , at each time interval t1, calculate the temperature rise rate and compare it with the standard rate, and return to step S3; S5, P 恒 After heating for a period of time, calculate the temperature rise ΔT3 and calculate q A , according to q A Calculate P A , output power P A , the heating power is fine-tuned and controlled by the PID algorithm. ΔT A =T 设 -T 环 (6) 2. A method for controlling temperature rise by using a micro switch instead of a water flow sensor according to claim 1, characterized in that: The standard deviation is determined by a standard deviation table developed by the laboratory, in which the water flow rate is divided into several levels, each level corresponding to a standard temperature rise rate.

3. The method for controlling temperature rise by using a micro switch instead of a water flow sensor according to claim 1, characterized in that: In the step S1, heating is performed with the initial power P0 for a period of time, which is 5 seconds.

4. The method for controlling temperature rise by using a micro switch instead of a water flow sensor according to claim 1, characterized in that: In step S4, the interval time t1 is 2s.

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