Vapor control method, device and equipment of evaporator and storage medium

Abstract

The invention discloses a steam control method, device and equipment of an evaporator and a storage medium. The method comprises the steps that the current actual steam generation amount of an evaporator in a water pump working period is obtained; the current designed steam generation amount of the evaporator in the working period of the water pump is obtained; calculating the current deviation percentage of the designed steam generation amount and the actual steam generation amount; if the absolute value of the current deviation percentage is larger than a preset threshold value, the target duty ratio of working of the water pump is obtained through a PID adjusting algorithm, and the water pump is made to operate at the target duty ratio in the next working period; and if the absolute value of the current deviation percentage is smaller than or equal to the preset threshold value, the water pump is controlled to operate at the current working duty ratio of the water pump in each later working period. When the deviation between the actual steam generation amount and the designed steam generation amount of the evaporator is not within the range below the preset threshold value, the new working duty ratio of the water pump can be obtained through the PID adjusting algorithm to adjust inlet water, the deviation is corrected, and the steam amount is more accurate.

Description

Technical Field

[0001] The present invention relates to the field of electrical appliance control, and in particular to a steam control method, device, equipment and storage medium for an evaporator. Background Art

[0002] The steam generator is the heart of the steam system. All steam is generated from here and transported to the inner cavity. The steaming function of steam cooking appliances (such as steam ovens) is to heat food by generating high-temperature steam in the evaporator.

[0003] In the steam cooking appliances with direct injection evaporators currently on the market, during the steam generation process, the water inlet amount in the evaporator will deviate from the design due to flow errors of the water pump and structural factors such as the water inlet pipe. This deviation will cause the actual amount of steam generated by the evaporator to be inconsistent with the designed steam amount. When reflected in the cooking process, it will easily lead to the cooking appliance failing to achieve the designed cooking effect. The prior art lacks a technical solution that can effectively adjust the water inlet of the evaporator to make the evaporator steam generation amount more accurate.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] The main purpose of the present invention is to solve the technical problem that the actual steam generation amount of the existing evaporator will be deviated due to the deviation of the water pump water intake amount, and the steam generation accuracy of the evaporator is not enough.

[0006] A first aspect of the present invention provides a steam control method for an evaporator, comprising the steps of:

[0007] Get the actual steam generation of the evaporator under the current water pump working cycle;

[0008] Obtaining the designed steam generation amount of the evaporator under the current working cycle of the water pump;

[0009] Calculating the current deviation percentage between the designed steam generation amount and the actual steam generation amount;

[0010] If the absolute value of the deviation percentage is greater than a preset threshold, the target duty cycle of the water pump is obtained through a preset PID adjustment algorithm, and the water pump is operated at the target duty cycle in the next water pump working cycle;

[0011] If the absolute value of the deviation percentage is less than or equal to a preset threshold, the water pump is controlled to operate at the current water pump operating duty cycle in each subsequent water pump operating cycle.

[0012] Optionally, in some implementations of the first aspect of the present invention, if the absolute value of the deviation percentage is greater than a preset threshold, obtaining a target duty cycle of the water pump operation by a preset PID adjustment algorithm includes:

[0013] Based on the multiplication of the preset proportional coefficient and the current deviation percentage, a proportional term value of the PID adjustment algorithm is obtained;

[0014] Obtain the cumulative total of all historical deviation percentages under each of the water pump working cycles up to the present, and obtain the integral term value of the PID control algorithm based on the multiplication of a preset integral coefficient and the cumulative total;

[0015] Obtaining the difference between the current deviation percentage and the previous deviation percentage in the last working cycle of the water pump, and multiplying the difference by a preset differential coefficient to obtain the differential term value of the PID control algorithm;

[0016] Adding the proportional term value, the integral term value, the differential term value and the actual average power of the evaporator in the current water pump working cycle to obtain the target actual power of the evaporator;

[0017] The target duty cycle of the water pump is obtained by dividing the target actual power by a preset power duty cycle correlation coefficient.

[0018] Optionally, in some implementations of the first aspect of the present invention, the formula of the PID adjustment algorithm is as follows:

[0019]

[0020] Wherein, γ is the power duty cycle correlation coefficient, t is the execution number mark of the water pump working cycle, the value of t is a positive integer from 1 to n, the current water pump working cycle is the t-th water pump working cycle, D(t) is the target duty cycle that needs to be calculated under the current water pump working cycle, P(t) is the actual average power of the evaporator under the current water pump working cycle, and ΔQ(t) is the current deviation percentage under the current water pump working cycle; is the cumulative total of all historical deviation percentages in each water pump working cycle up to now; ΔQ(t-1) is the previous deviation percentage in the last water pump working cycle, K p is the proportionality coefficient, K i is the integral coefficient, K d is the differential coefficient, subscript p, subscript i and subscript d are identifiers for distinguishing the coefficients from each other, and when t=1, the value of ΔQ(t-1) is zero by default.

[0021] Optionally, in some implementations of the first aspect of the present invention, causing the water pump to operate at the target duty cycle in the next water pump working cycle includes:

[0022] The on-time of the water pump in the next water pump working cycle is fixed unchanged, and the cycle time of the water pump in the next water pump working cycle is changed, so that the water pump operates at the target duty cycle in the next water pump working cycle.

[0023] Optionally, in some implementations of the first aspect of the present invention, causing the water pump to operate at the target duty cycle in the next water pump working cycle includes:

[0024] The cycle duration of the next water pump working cycle of the water pump is fixed and unchanged, and the opening duration of the water pump in the next water pump working cycle is changed, so that the water pump operates at the target duty cycle in the next water pump working cycle.

[0025] Optionally, in some implementations of the first aspect of the present invention, obtaining the actual steam generation amount of the evaporator under the current water pump working cycle includes:

[0026] Obtain the power-time variation curve of the evaporator under the current water pump working cycle;

[0027] Based on the power time variation curve, the actual average power of the evaporator under the working cycle of the water pump is calculated;

[0028] The actual lossless steam conversion amount of the evaporator is obtained by multiplying the actual average power by a preset steam power conversion coefficient;

[0029] Based on the subtraction of the actual lossless steam conversion amount from the preset fixed loss steam amount, the actual steam generation amount of the evaporator in the current working cycle of the water pump is obtained.

[0030] Optionally, in some implementations of the first aspect of the present invention, the calculating based on the power time variation curve to obtain the actual average power of the evaporator under the water pump working cycle currently includes:

[0031] Obtaining a target time period for the evaporator to process the water inflow during the current working cycle of the water pump from the power time variation curve;

[0032] Obtaining the working time and the stopping time of the evaporator from the target time period;

[0033] Based on the power change of the evaporator during the working time, the total work done by the evaporator is calculated;

[0034] The actual average power of the evaporator in the current working cycle of the water pump is obtained by dividing the total work done by the total duration of the target time period.

[0035] Optionally, in some implementations of the first aspect of the present invention, obtaining the designed steam generation amount of the evaporator under the current working cycle of the water pump includes:

[0036] Obtaining the current designed average power of the evaporator under the working cycle of the water pump;

[0037] The designed lossless steam conversion capacity of the evaporator is obtained by multiplying the designed average power and a preset steam power conversion coefficient;

[0038] Based on the subtraction of the designed lossless steam conversion amount from the preset fixed loss steam amount, the designed steam generation amount of the evaporator under the current working cycle of the water pump is obtained. Optionally, in some implementations of the first aspect of the present invention, the steam control method further includes:

[0039] Real-time collection of the duration of each power-on of the relay that controls the operation of the evaporator;

[0040] Compare the duration of each power-on of the relay with the preset dry-burning judgment duration;

[0041] For each power-on of the relay, if the power-on time of the relay is less than the preset dry-burning judgment time, it is determined that the evaporator is dry-burning.

[0042] A second aspect of the present invention provides a steam control device for an evaporator, the steam control device comprising:

[0043] The actual steam generation amount acquisition module is used to obtain the actual steam generation amount of the evaporator under the current water pump working cycle;

[0044] A designed steam generation amount acquisition module is used to obtain the designed steam generation amount of the evaporator under the current working cycle of the water pump;

[0045] A deviation percentage calculation module, used to calculate the current deviation percentage between the designed steam generation amount and the actual steam generation amount;

[0046] A dynamic duty cycle operation module, for obtaining a target duty cycle of the water pump through a preset PID adjustment algorithm if the absolute value of the deviation percentage is greater than a preset threshold value, and causing the water pump to operate at the target duty cycle in the next water pump working cycle;

[0047] The fixed duty cycle operation module is used to control the water pump to operate at the current water pump operating duty cycle in each subsequent water pump working cycle if the absolute value of the current deviation percentage is less than or equal to a preset threshold.

[0048] A third aspect of the present invention provides a steam control device for an evaporator, the steam control device for an evaporator comprising: a memory and at least one processor, the memory storing instructions, the memory and the at least one processor being interconnected via a line;

[0049] The at least one processor calls the instructions in the memory to enable the steam control device of the evaporator to execute the steam control method of the evaporator as described in any one of the first aspects above.

[0050] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steam control method for an evaporator as described in any one of the first aspects above is implemented.

[0051] Beneficial effects: The present invention discloses a steam control method, device, equipment and storage medium for an evaporator. The method includes obtaining the actual steam generation of the evaporator under the current working cycle of the water pump; obtaining the designed steam generation of the evaporator under the current working cycle of the water pump; calculating the current deviation percentage between the designed steam generation and the actual steam generation; if the absolute value of the current deviation percentage is greater than the preset threshold, the target duty cycle of the water pump is obtained through the PID adjustment algorithm, and the water pump is operated at the target duty cycle in the next working cycle; if the absolute value of the current deviation percentage is less than or equal to the preset threshold, the water pump is controlled to operate at the current duty cycle of the water pump in each subsequent working cycle. When the deviation between the actual steam generation and the designed steam generation of the evaporator is not within the range below the preset threshold, the present invention will obtain a new duty cycle of the water pump through the PID adjustment algorithm to adjust the water intake, correct the deviation, and make the steam volume more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 The figure is a schematic diagram of the structure of an exemplary steam cooking appliance in an embodiment of the present invention.

[0053] Figure 2 The figure is a flow chart of a steam control method for an evaporator according to an exemplary embodiment of the present invention.

[0054] Figure 3 The figure is a schematic diagram of a power time variation curve of an exemplary evaporator in an embodiment of the present invention.

[0055] Figure 4 For the embodiment of the present invention Figure 2A schematic diagram of a specific implementation of step S100 in the flowchart.

[0056] Figure 5 The closed-loop control flow chart of an exemplary PID adjustment algorithm in an embodiment of the present invention.

[0057] Figure 6 For the embodiment of the present invention Figure 2 A schematic diagram of a specific implementation of step S400 in the flowchart.

[0058] Figure 7 The figure is a schematic diagram of the module composition of a steam control device for an evaporator according to an exemplary embodiment of the present invention.

[0059] Figure 8 It is a schematic structural diagram of a steam control device of an evaporator exemplarily in an embodiment of the present invention. DETAILED DESCRIPTION

[0060] The embodiments disclosed in the present invention are described in more detail below with reference to the accompanying drawings. Although certain embodiments disclosed in the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided for a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments disclosed in the present invention are only for exemplary purposes and are not intended to limit the scope of protection disclosed in the present invention.

[0061] In the description of the embodiments disclosed in the present invention, if there are terms, the term "including" and similar terms should be understood as open inclusion, that is, "including but not limited to". The term "based on" should be understood as "based at least in part on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc. can refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0062] To facilitate understanding, the specific process of an embodiment of the present invention is described below. The first aspect of the present invention provides a steam control method for an evaporator. An exemplary application scenario of the steam control method of the present invention is a heated direct-injection evaporator. The steam sprayed from the heated direct-injection evaporator is high-temperature steam, which can quickly increase the cavity temperature.

[0063] In the first aspect of the present invention, the household appliance used for the evaporator may be various steam cooking appliances (such as steamers and steam ovens), see Figure 1In an exemplary steam cooking appliance of the present invention, the steam cooking appliance includes a housing 10, in which a control panel 20, a water pump 30, a water inlet pipe 40, an evaporator 50, an evaporator NTC temperature sensor (arranged in the evaporator 50) and a steam outlet pipe 60 are arranged. When the steam is working, the working mode of the evaporator 50 is that when the temperature collected by the evaporator NTC temperature sensor is greater than or equal to a preset temperature value (100-160°C, for example, 140°C), the control panel 20 controls the relay of the evaporator 50 to be closed, and when the temperature collected by the evaporator NTC temperature sensor is less than the preset temperature value, the control panel 20 controls the relay of the evaporator 50 to be opened. When the evaporator 50 is working, the temperature will fluctuate around the preset temperature value (with the preset temperature value being 140°C). ℃ as an example, the temperature fluctuation range of the evaporator 50 may be 120-160℃), when the temperature of the evaporator 10 is greater than the lower limit of the temperature fluctuation range, the water pump 30 performs pulse work through a certain proportion of duty cycle (the duty cycle can be exemplarily 100ms / 2000ms, wherein 2000ms is the cycle duration of the working cycle of the water pump 30, 100ms is the on time of the water pump within the cycle duration, and the off time of the water pump 30 within the cycle duration is 1900ms) to add water to the evaporator 50.

[0064] In the existing steam generation system where water is supplied to the evaporator by a water pump, due to the flow rate of the water pump and the structural factors of the water inlet pipe, the water inlet amount will have a certain deviation from the design. This deviation will cause the actual steam amount to be inconsistent with the designed steam amount. In order to solve this technical problem of the prior art, see Figure 2 The steam control method of the evaporator of the present invention comprises the steps of:

[0065] S100, obtaining the actual steam generation of the evaporator under the current water pump working cycle; in this step of the present invention, the actual steam generation of the evaporator can be directly read from the program of the control board, or can be obtained by reading relevant data from the program and calculating.

[0066] For example, the actual steam generation is not directly stored in the control panel program, see Figure 3 The step of obtaining the actual steam generation amount in step S100 may be:

[0067] A101. Obtain the power-time variation curve of the evaporator under the current water pump working cycle. In the present invention, the evaporator works in a mode in which when the temperature collected by the NTC temperature sensor of the evaporator is greater than or equal to the preset temperature value, the relay is closed, and when the temperature collected by the NTC temperature sensor of the evaporator is less than the preset temperature value, the relay is opened. That is, the evaporator can adaptively evaporate the water pumped by the water pump. If the amount of water pumped by the water pump in each working cycle is different, it will be specifically reflected in the evaporator that the evaporator needs to work longer for each water pump working cycle, that is, the average power of the evaporator in each water pump working cycle will change. The power change of the evaporator will form a curve such as Figure 4 The power time variation curve is shown.

[0068] A102. Calculate the actual average power of the evaporator under the water pump working cycle based on the power time variation curve; specifically, step A102 includes: obtaining the target time period for the evaporator to process the water intake of the current water pump working cycle from the power time variation curve; obtaining the working time and stop time of the evaporator from the target time period; calculate the total work of the evaporator based on the power variation of the evaporator during the working time; and obtain the actual average power of the evaporator under the water pump working cycle by dividing the total work by the total time period.

[0069] In the present invention, the working mode of the evaporator is that water is pumped into the evaporator. In order to maintain the temperature at a preset temperature value, the evaporator will automatically start heating (that is, the relay controlling the evaporator is energized). When the pumped water is completely evaporated, the evaporator will turn off the heating (that is, the relay controlling the evaporator is de-energized). Therefore, the time point when the water pump starts pumping water is used as the reference time node. The power change law of the evaporator is used in the power time change curve after the reference time node (the power at the time point means that the evaporator is energized) to find the target time period for the evaporator to process the water intake volume pumped in each working cycle of the water pump. The working time (the time when the power has a value on the power time change curve) and the stop time (the time when the power has no value (that is, the value is zero) on the power time change curve) of the evaporator found in the target time period can be used to obtain the actual average power of the evaporator in the current working cycle of the water pump.

[0070] A103. The actual lossless steam conversion amount of the evaporator is obtained by multiplying the actual average power by the preset steam power conversion coefficient. Specifically, in the evaporator steam generation model of the present invention, the calculation formula of the evaporator steam generation amount should be: Q = α*TX, X is the fixed steam loss amount, X is the steam loss amount caused by the heat loss of the evaporator itself when it is working, α is the steam conversion amount per unit time of the evaporator, T is the opening time of the evaporator, and α*T is equal to the average power P of the evaporator during evaporation. 平 The product of the coefficient β (i.e., the steam power conversion coefficient), so the calculation formula of the evaporator steam generation can also be converted to Q = β * P 平 -X, in the present invention, in order to obtain the actual steam generation of the evaporator under the actual average power, firstly, the product of the actual average power and the steam power conversion coefficient β (i.e. β*P 平 ), that is, firstly obtain the actual lossless steam conversion amount of the actual average power losslessly converted into steam.

[0071] A104, based on the actual lossless steam conversion amount and the preset fixed loss steam amount, the actual steam generation amount of the evaporator under the current working cycle of the water pump is obtained. In the present invention, after the actual lossless steam conversion amount is obtained, the fixed steam loss amount T (that is, β*P 平 -X), the actual steam generation amount of the evaporator under the actual average power can be obtained.

[0072] S200, obtaining the designed steam generation of the evaporator under the current working cycle of the water pump; in this step of the present invention, the designed steam generation of the evaporator can be directly read from the program of the control panel, or can be obtained by reading relevant data from the program and calculating. The calculation formula of the steam generation of the designed steam generation of the evaporator under the current working cycle of the water pump and the calculation formula of the actual steam generation of the evaporator under the current working cycle of the water pump are the same set of formulas, both of which are Q=β*P 平 -X, the difference between the two calculation methods is that when calculating the design steam generation of the evaporator under the current working cycle of the water pump, the P 平 is the designed average power of the evaporator.

[0073] In step S200, obtaining the current designed steam generation of the evaporator under the water pump working cycle includes: obtaining the current designed average power of the evaporator under the water pump working cycle; obtaining the designed lossless steam conversion amount of the evaporator based on multiplying the designed average power and a preset steam power conversion coefficient; obtaining the current designed steam generation of the evaporator under the water pump working cycle based on subtracting the designed lossless steam conversion amount from a preset fixed loss steam amount.

[0074] S300, calculating the current deviation percentage between the designed steam generation and the actual steam generation; in the present invention, the technical problem to be solved by the present invention is the inconsistency between the designed steam generation and the actual steam generation of the evaporator, and the premise for solving the technical problem is to first compare the designed steam generation with the actual steam generation to determine whether the difference between the designed steam generation and the actual steam generation is within a reasonable range.

[0075] In step S300 of the present invention, the calculation formula of the current deviation percentage can be as follows:

[0076]

[0077] , where ΔQ is the deviation percentage, Q1 is the actual steam generation, and Q2 is the designed steam generation. Of course, in the present invention, the calculation method of the deviation percentage can also be to swap the positions of the actual steam generation and the designed steam generation, and the relevant coefficients of the subsequent calculation formulas with the deviation percentage need to be adjusted in positive and negative signs.

[0078] S400. If the absolute value of the deviation percentage is greater than a preset threshold, the target duty cycle of the water pump is obtained through a preset PID adjustment algorithm, and the water pump is operated at the target duty cycle in the next water pump working cycle; in the present invention, if the absolute value of the deviation percentage is greater than a preset threshold (e.g., 1-5%, e.g., 1%), it is considered that the accuracy of the steam generation amount of the evaporator is not within the allowable range and needs to be adjusted, and the way to adjust the actual steam generation amount of the evaporator is mainly to adjust the water intake, which is converted into specific parameters, that is, to adjust the duty cycle of the water pump. When the water pump flow rate is constant, the larger the duty cycle of the water pump, the more water the water pump delivers, and conversely, the smaller the duty cycle of the water pump, the less water the water pump delivers.

[0079] In the present invention, the duty cycle of the water pump is adjusted by a preset PID adjustment algorithm. The PID adjustment algorithm is a common "maintain stability" control algorithm, which consists of three parts: proportional, integral, and derivative. It is used to automatically and accurately correct the control system. Proportional part: directly adjust the control amount proportionally according to the size of the error to reduce the error. Integral part: adjust the control amount by accumulating the error to eliminate the static error. Derivative part: adjust the control amount in advance according to the rate of change of the error to speed up the response speed of the system and reduce overshoot. The differential control effect helps the system reduce overshoot, overcome oscillation, speed up the response speed, and reduce the adjustment time, thereby improving the dynamic performance of the system.

[0080] In an exemplary implementation of the first aspect of the present invention, the formula of the PID adjustment algorithm can be summarized as follows:

[0081]

[0082] Wherein, γ is the power duty cycle correlation coefficient, t is the execution number mark of the water pump working cycle, the value of t is a positive integer from 1 to n, the current water pump working cycle is the t-th water pump working cycle, D(t) is the target duty cycle that needs to be calculated under the current water pump working cycle, P(t) is the actual average power of the evaporator under the current water pump working cycle, and ΔQ(t) is the current deviation percentage under the current water pump working cycle; is the cumulative total of all historical deviation percentages in each water pump working cycle up to now; ΔQ(t-1) is the previous deviation percentage in the last water pump working cycle, K p is the proportionality coefficient, K i is the integral coefficient, K d is the differential coefficient, subscript p, subscript i and subscript d are identifiers for distinguishing the coefficients from each other, and when t=1, the value of ΔQ(t-1) defaults to zero. The closed-loop control flow chart of the PID adjustment algorithm of the present invention can be as follows: Figure 5 As shown, in Figure 5 In the figure, Q2(t) is the designed steam generation of the evaporator under the t-th working cycle of the water pump, and Q1(t) is the actual steam generation of the evaporator under the t-th working cycle of the water pump.

[0083] In some optional implementations of step S400 of the present invention, see Figure 6If the absolute value of the deviation percentage is greater than a preset threshold, the target duty cycle of the water pump is obtained by a preset PID adjustment algorithm, including:

[0084] A401, based on the preset proportional coefficient and the current deviation percentage multiplied, obtain the proportional term value of the PID adjustment algorithm; in this step, it is to calculate the K in the formula of the PID adjustment algorithm. p *The value of ΔQ(t).

[0085] A402, obtain the cumulative deviation percentages of all the pump working cycles so far, and obtain the integral term value of the PID control algorithm based on the preset integral coefficient and the cumulative multiplication; in this step, it is necessary to calculate the formula of the PID control algorithm. The numerical value of .

[0086] A403, obtain the difference between the current deviation percentage and the deviation percentage of the previous pump working cycle, and multiply the difference by the preset differential coefficient to obtain the differential term value of the PID adjustment algorithm; in this step, K is calculated. d *(ΔQ(t)-ΔQ(t-1) value.

[0087] A404, adding the proportional term value, the integral term value, the differential term value and the actual average power of the evaporator under the current water pump working cycle to obtain the target actual power of the evaporator; in this step, the target actual power of the evaporator is calculated. In this step, and The sum of the three can be understood as the average power ΔP(t) that the evaporator needs to change under the condition of the actual average power of the evaporator under the tth working cycle of the water pump in order to enable the evaporator to generate the designed steam generation amount of steam. Through P(t)+ΔP(t), the target actual power that the evaporator needs to achieve is obtained.

[0088] A405: Divide the target actual power by the preset power duty cycle correlation coefficient to obtain the target duty cycle of the water pump. The accumulation of is divided by the coefficient γ in the PID adjustment algorithm, so as to obtain the target duty cycle of the water pump, i.e. D(t). In the present invention, the coefficient γ can be an empirical value set manually, or it can be obtained by dividing the actual average power of the evaporator in the first water pump working cycle and the duty cycle of the water pump in the first water pump working cycle. The latter acquisition method is intended to simplify the number of simulation experiments required to obtain the empirical value. When the coefficient γ is obtained by the latter acquisition method, when the PID adjustment algorithm is adjusted, only the number of water pump working cycles that need to be executed is slightly increased when the absolute value of the deviation percentage between the actual steam generation and the designed steam generation finally meets the preset threshold requirement.

[0089] In the present invention, the duty cycle of the water pump is obtained by dividing the on-time of the water pump in the working cycle of the water pump by the cycle time of the working cycle of the water pump. That is to say, there are two ways to change the duty cycle of the water pump, one is to change the on-time of the water pump in the working cycle of the water pump, and the other is to change the cycle time of the working cycle of the water pump. Specifically, in the first aspect of the present invention, the water pump is operated at the target duty cycle in the next working cycle of the water pump, including the following two ways:

[0090] (1) The on-time of the water pump in the next water pump working cycle is fixed and the cycle time of the water pump in the next water pump working cycle is changed so that the water pump operates at the target duty cycle in the next water pump working cycle.

[0091] (2) The cycle duration of the next water pump working cycle of the water pump is fixed and the opening duration of the water pump in the next water pump working cycle is changed so that the water pump operates at the target duty cycle in the next water pump working cycle.

[0092] S500, if the absolute value of the deviation percentage is less than or equal to the preset threshold, the water pump is controlled to operate at the current water pump duty cycle in each subsequent water pump working cycle. In the present invention, if the absolute value of the deviation percentage is less than or equal to the preset threshold, it is considered that the difference between the designed steam generation amount and the actual steam generation amount of the evaporator is within a reasonable range, and the duty cycle of the water pump and the actual average power of the evaporator to achieve the designed steam generation amount are matched, so there is no need to adjust the current water pump duty cycle.

[0093] By quantifying the steam volume using the steam control method data of the evaporator of the present invention, the error between the actual steam generation volume and the designed steam generation volume of the evaporator can be made smaller. When used in a steam cooking appliance, different set steam volumes are set according to different recipes for cooking tests, and the cooking parameters of the recipe finally debugged will also be more accurate, thereby achieving better cooking effects.

[0094] In some optional implementations of the first aspect of the present invention, the steam control method further includes: real-time collection of the duration of each power-on of the relay that controls the operation of the evaporator; comparing the duration of each power-on of the relay with a preset dry-burn judgment duration; for each power-on of the relay, if the duration of the power-on of the relay is less than the preset dry-burn judgment duration, it is determined that the evaporator is dry-burned.

[0095] Specifically, as described in the opening paragraph, and taking the preset temperature of 140°C as an example, the working mode of the evaporator of the present invention is that when the temperature collected by the NTC temperature sensor of the evaporator is greater than 140°C, the relay controlling the operation of the evaporator will be closed, and when the temperature collected by the NTC temperature sensor is less than 140°C, the relay controlling the operation of the evaporator will be opened, and the temperature of the evaporator will be maintained between 120-160°C when it is working.

[0096] If no water is added to the evaporator, after the evaporator reaches above 140℃, the temperature will drop due to heat dissipation. After dropping below 140℃, the relay controlling the operation of the evaporator will open. However, the relay controlling the operation of the evaporator is turned on for a short time before the temperature of the evaporator rises to above 140℃ again. When water is added to the evaporator, the added water needs to be heated when the evaporator temperature rises back to above 140℃. Therefore, the opening time of the relay controlling the operation of the evaporator will be greatly extended. By judging whether the power-on time of the relay controlling the operation of the evaporator is less than a preset dry-burning judgment time each time, it can be judged whether the evaporator has dry-burned. If the power-on time of the relay each time is greater than the preset dry-burning judgment time, it proves that the evaporator is not dry-burned after water is added, and vice versa.

[0097] See also Figure 7 According to a second aspect of the present invention, there is provided a steam control device for an evaporator, the steam control device comprising:

[0098] The actual steam generation amount acquisition module 70 is used to acquire the actual steam generation amount of the evaporator under the current water pump working cycle;

[0099] The designed steam generation amount acquisition module 80 is used to acquire the designed steam generation amount of the evaporator under the current working cycle of the water pump;

[0100] A deviation percentage calculation module 90 is used to calculate the current deviation percentage between the designed steam generation amount and the actual steam generation amount;

[0101] The dynamic duty cycle operation module 100 is used to obtain the target duty cycle of the water pump through a preset PID adjustment algorithm if the absolute value of the deviation percentage is greater than a preset threshold value, and to make the water pump operate at the target duty cycle in the next water pump working cycle;

[0102] The fixed duty cycle operation module 110 is used to control the water pump to operate at the current water pump operating duty cycle in each subsequent water pump working cycle if the absolute value of the current deviation percentage is less than or equal to a preset threshold.

[0103] In some optional implementations of the second aspect of the present invention, the dynamic duty cycle operation module includes:

[0104] A proportional term calculation unit, used to obtain a proportional term value of the PID adjustment algorithm based on multiplying a preset proportional coefficient by the current deviation percentage;

[0105] An integral term calculation unit, used to obtain the accumulation of all historical deviation percentages under each of the water pump working cycles up to the present, and obtain the integral term value of the PID control algorithm based on the multiplication of a preset integral coefficient and the accumulation;

[0106] A differential term calculation unit, used to obtain the difference between the current deviation percentage and the previous deviation percentage of the last working cycle of the water pump, and obtain the differential term value of the PID adjustment algorithm based on multiplying the difference by a preset differential coefficient;

[0107] a target actual power calculation unit, configured to add the proportional term value, the integral term value, the differential term value and the actual average power of the evaporator in the current water pump working cycle to obtain the target actual power of the evaporator;

[0108] The target duty cycle calculation unit is used to obtain the target duty cycle of the water pump based on the division of the target actual power and the preset power duty cycle correlation coefficient.

[0109] In some optional implementations of the second aspect of the present invention, the dynamic duty cycle operation module further includes:

[0110] The cycle duration adjusting operation unit is used to fix the opening duration of the water pump in the next water pump working cycle and change the cycle duration of the water pump in the next water pump working cycle so that the water pump runs at the target duty cycle in the next water pump working cycle.

[0111] In some optional implementations of the second aspect of the present invention, the dynamic duty cycle operation module further includes:

[0112] The on-time adjustment operation unit fixes the cycle duration of the water pump in the next water pump working cycle and changes the on-time of the water pump in the next water pump working cycle, so that the water pump runs at the target duty cycle in the next water pump working cycle.

[0113] In some optional implementations of the second aspect of the present invention, the actual steam generation amount acquisition module includes:

[0114] A power time curve acquisition unit is used to acquire the power time variation curve of the evaporator under the current water pump working cycle;

[0115] An actual average power calculation unit, used for calculating the actual average power of the evaporator under the working cycle of the water pump based on the power time variation curve;

[0116] an actual lossless steam conversion amount calculation unit, configured to obtain an actual lossless steam conversion amount of the evaporator based on multiplying the actual average power by a preset steam power conversion coefficient;

[0117] The actual steam generation amount calculation unit is used to obtain the actual steam generation amount of the evaporator under the current working cycle of the water pump based on the subtraction of the actual lossless steam conversion amount from the preset fixed loss steam amount.

[0118] In some optional implementations of the second aspect of the present invention, the actual average power calculation unit includes:

[0119] A target time period acquisition subunit, used to acquire a target time period for the evaporator to process the water inflow during the current working cycle of the water pump from the power time variation curve;

[0120] A time period analysis subunit, used for obtaining the working time and the stopping time of the evaporator from the target time period;

[0121] a work calculation subunit, configured to calculate the total work of the evaporator based on the power change of the evaporator during the working time;

[0122] The power calculation subunit is used to obtain the actual average power of the evaporator under the current working cycle of the water pump by dividing the total work done by the total duration of the target time period.

[0123] In some optional implementations of the second aspect of the present invention, the designed steam generation amount acquisition module includes:

[0124] A designed average power acquisition unit, used to acquire the designed average power of the evaporator under the current working cycle of the water pump;

[0125] a designed lossless steam conversion amount calculation unit, used for obtaining the designed lossless steam conversion amount of the evaporator based on the multiplication of the designed average power and a preset steam power conversion coefficient;

[0126] The designed steam generation amount calculation unit is used to obtain the designed steam generation amount of the evaporator under the current working cycle of the water pump based on the subtraction of the designed lossless steam conversion amount from the preset fixed loss steam amount.

[0127] In some optional implementations of the second aspect of the present invention, the steam control device further includes:

[0128] The evaporator continuous opening time acquisition unit is used to collect the duration of each power-on of the relay controlling the operation of the evaporator in real time;

[0129] A duration comparison unit, used for comparing the duration of each power-on of the relay with a preset dry-burning judgment duration;

[0130] The dry-burn determination unit is used for determining that the evaporator is dry-burned if the duration of the relay being powered on is less than a preset dry-burn determination duration each time the relay is powered on.

[0131] Figure 8 1 is a schematic diagram of the structure of a steam control device for an evaporator provided in an embodiment of the present invention. The steam control device 120 for the evaporator may have relatively large differences due to different configurations or performances, and may include one or more processors (central processing units, CPU) 130 (for example, one or more processors) and a memory 140, and one or more storage media 160 (for example, one or more mass storage devices) for storing application programs 150 or data. Among them, the memory and the storage medium may be short-term storage or permanent storage. The program stored in the storage medium may include one or more modules (not shown in the figure), and each module may include a series of instruction operations in the steam control device of the evaporator. Furthermore, the processor may be configured to communicate with the storage medium to execute a series of instruction operations in the storage medium on the steam control device of the evaporator.

[0132] The steam control device of the evaporator of the present invention may also include one or more power supplies 170, one or more wired or wireless network interfaces 180, one or more input and output interfaces 190, and / or one or more operating systems 200, such as Windows Serve, Mac OS X, Unix, Linux, FreeBSD, etc. It will be understood by those skilled in the art that Figure 8 The illustrated steam control device structure of the evaporator does not constitute a limitation on the steam control device based on the evaporator, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0133] The present invention also provides a computer-readable storage medium, which may be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium. Instructions are stored in the computer-readable storage medium. When the instructions are executed on a computer, the computer executes the steps of the steam control method of the evaporator.

[0134] In the context of the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0135] In addition, although each operation is described in a specific order, this should be understood as requiring such operation to be performed in the specific order shown or in a sequential order, or requiring that all illustrated operations should be performed to obtain desired results. Under certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although some specific implementation details are included in the above discussion, these should not be interpreted as limiting the scope of the present disclosure. Some features described in the context of a separate embodiment can also be implemented in a single implementation in combination. On the contrary, the various features described in the context of a single implementation can also be implemented in multiple implementations individually or in any suitable sub-combination mode.

[0136] Although the subject matter has been described in language specific to structural features and / or methodological logical actions, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. On the contrary, the specific features and actions described above are merely example forms of implementing the claims.

Claims

1. A steam control method for an evaporator, characterized in that: Includes steps: Get the actual steam generation of the evaporator under the current water pump working cycle; Obtaining the designed steam generation amount of the evaporator under the current working cycle of the water pump; Calculating the current deviation percentage between the designed steam generation amount and the actual steam generation amount; If the absolute value of the deviation percentage is greater than a preset threshold, the target duty cycle of the water pump is obtained through a preset PID adjustment algorithm, and the water pump is operated at the target duty cycle in the next water pump working cycle; If the absolute value of the deviation percentage is less than or equal to a preset threshold, the water pump is controlled to operate at the current water pump operating duty cycle in each subsequent water pump operating cycle.

2. The steam control method of the evaporator according to claim 1, characterized in that: If the absolute value of the deviation percentage is greater than a preset threshold, the target duty cycle of the water pump is obtained by a preset PID adjustment algorithm, including: Based on the multiplication of the preset proportional coefficient and the current deviation percentage, a proportional term value of the PID adjustment algorithm is obtained; Obtain the cumulative total of all historical deviation percentages under each of the water pump working cycles up to the present, and obtain the integral term value of the PID control algorithm based on the multiplication of a preset integral coefficient and the cumulative total; Obtaining the difference between the current deviation percentage and the previous deviation percentage in the last working cycle of the water pump, and multiplying the difference by a preset differential coefficient to obtain the differential term value of the PID control algorithm; Adding the proportional term value, the integral term value, the differential term value and the actual average power of the evaporator in the current water pump working cycle to obtain the target actual power of the evaporator; The target duty cycle of the water pump is obtained based on dividing the target actual power by a preset power duty cycle correlation coefficient.

3. The steam control method of the evaporator according to claim 2, characterized in that: The formula of the PID adjustment algorithm is as follows: Wherein, γ is the power duty cycle correlation coefficient, t is the execution number mark of the water pump working cycle, the value of t is a positive integer from 1 to n, the current water pump working cycle is the t-th water pump working cycle, D(t) is the target duty cycle that needs to be calculated under the current water pump working cycle, P(t) is the actual average power of the evaporator under the current water pump working cycle, and ΔQ(t) is the current deviation percentage under the current water pump working cycle; is the cumulative total of all historical deviation percentages in each water pump working cycle up to now; ΔQ(t-1) is the previous deviation percentage in the last water pump working cycle, K p is the proportionality coefficient, K i is the integral coefficient, K d is the differential coefficient, subscript p, subscript i and subscript d are identifiers for distinguishing the coefficients from each other, and when t=1, the value of ΔQ(t-1) is zero by default.

4. The steam control method of an evaporator according to claim 1, characterized in that: The step of causing the water pump to operate at the target duty cycle in the next water pump working cycle includes: The on-time of the water pump in the next water pump working cycle is fixed unchanged, and the cycle time of the water pump in the next water pump working cycle is changed, so that the water pump operates at the target duty cycle in the next water pump working cycle.

5. The steam control method of the evaporator according to claim 1, characterized in that: The step of causing the water pump to operate at the target duty cycle in the next water pump working cycle includes: The cycle duration of the next water pump working cycle of the water pump is fixed and unchanged, and the opening duration of the water pump in the next water pump working cycle is changed, so that the water pump operates at the target duty cycle in the next water pump working cycle.

6. The steam control method of an evaporator according to claim 1, characterized in that: The step of obtaining the actual steam generation amount of the evaporator under the current water pump working cycle includes: Obtain the power-time variation curve of the evaporator under the current water pump working cycle; Based on the power time variation curve, the actual average power of the evaporator under the working cycle of the water pump is calculated; The actual lossless steam conversion amount of the evaporator is obtained by multiplying the actual average power by a preset steam power conversion coefficient; Based on the subtraction of the actual lossless steam conversion amount from the preset fixed loss steam amount, the actual steam generation amount of the evaporator in the current working cycle of the water pump is obtained.

7. The steam control method of the evaporator according to claim 6, characterized in that: The actual average power of the evaporator currently calculated based on the power time variation curve under the water pump working cycle includes: Obtaining a target time period for the evaporator to process the water inflow during the current working cycle of the water pump from the power time variation curve; Obtaining the working time and the stopping time of the evaporator from the target time period; Based on the power change of the evaporator during the working time, the total work done by the evaporator is calculated; The actual average power of the evaporator in the current working cycle of the water pump is obtained by dividing the total work done by the total duration of the target time period.

8. The steam control method of an evaporator according to claim 1, characterized in that: The obtaining of the designed steam generation amount of the evaporator under the current working cycle of the water pump comprises: Obtaining the current designed average power of the evaporator under the working cycle of the water pump; The designed lossless steam conversion capacity of the evaporator is obtained by multiplying the designed average power and a preset steam power conversion coefficient; Based on the subtraction of the designed lossless steam conversion amount from the preset fixed loss steam amount, the designed steam generation amount of the evaporator under the current working cycle of the water pump is obtained.

9. The steam control method of an evaporator according to any one of claims 1 to 8, characterized in that: The steam control method further comprises: Real-time collection of the duration of each power-on of the relay that controls the operation of the evaporator; Compare the duration of each power-on of the relay with the preset dry-burning judgment duration; For each power-on of the relay, if the power-on time of the relay is less than the preset dry-burning judgment time, it is determined that the evaporator is dry-burning.

10. A steam control device for an evaporator, characterized in that: The steam control device comprises: The actual steam generation amount acquisition module is used to obtain the actual steam generation amount of the evaporator under the current water pump working cycle; A designed steam generation amount acquisition module is used to obtain the designed steam generation amount of the evaporator under the current working cycle of the water pump; A deviation percentage calculation module, used to calculate the current deviation percentage between the designed steam generation amount and the actual steam generation amount; A dynamic duty cycle operation module, for obtaining a target duty cycle of the water pump through a preset PID adjustment algorithm if the absolute value of the deviation percentage is greater than a preset threshold value, and causing the water pump to operate at the target duty cycle in the next water pump working cycle; The fixed duty cycle operation module is used to control the water pump to operate at the current water pump operating duty cycle in each subsequent water pump working cycle if the absolute value of the current deviation percentage is less than or equal to a preset threshold.

11. A steam control device for an evaporator, characterized in that: The steam control device of the evaporator comprises: a memory and at least one processor, the memory stores instructions, and the memory and the at least one processor are interconnected via a line; The at least one processor calls the instructions in the memory to enable the steam control device of the evaporator to execute the steam control method of the evaporator according to any one of claims 1-9.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steam control method of the evaporator according to any one of claims 1 to 9 is implemented.

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