A temperature control method for an instant milk frother and an instant milk frother with high-precision temperature control

Abstract

The application discloses a temperature control method of an instant heating type milk frother and an instant heating type milk frother with high-precision temperature control, and the method comprises the following steps: in step one, a control unit collects a set temperature T1 set by a user, water inlet temperature T2 of a water inlet, water outlet temperature T3 of a water outlet and cavity volume V1 of an instant heater in the instant heating type milk frother; in step two, the control unit calculates the heating power of the instant heater when the instant heater is started according to the water inlet temperature T2 and the water outlet temperature T3, so that the water outlet at the first time is the set temperature T1.

Description

Technical Field

[0001] The invention belongs to the technical field of milk mixers, and in particular relates to a temperature control method for an instant hot milk mixer and a high-precision temperature-controlled instant hot milk mixer. Background Art

[0002] A milk mixer, also known as a milk conditioner, was originally used to warm boiled water to a suitable drinking temperature for babies. It was used to mix formula for feeding, and because it maintains a constant water temperature, it's also known as a constant-temperature milk conditioner. Currently, there are two main types of milk conditioners for mothers and infants: one uses a heating plate or tube to heat and maintain the set temperature. This can lead to over-boiling water while maintaining the temperature, or the water cooling down too slowly after heating. The other uses an instant heating method, which heats and pumps water simultaneously. However, these are currently primarily targeted at adults making tea or coffee. Temperature accuracy requirements are not strict, and there's no targeted technical development. This can lead to milk temperatures being too high or too low, especially in winter and summer when environmental impacts are severe. The accuracy is typically greater than ±5°C. Therefore, current instant heating milk conditioners lack sufficient heating temperature accuracy. The industry's standard for in-cup temperature accuracy is generally within ±5°C. Consequently, when formula is required to be prepared within a range of 40°C to 55°C, temperatures too high can cause discomfort to infants, while too low can prevent the formula from dissolving. Consequently, current instant heating milk conditioners fail to meet the precise temperature control requirements.

[0003] This type of instant milk mixer features a water temperature sampling sensor at the outlet. By comparing the outlet water temperature with the set temperature, the heater power is adjusted to control the output water temperature. This temperature control method involves comparing the user-set temperature T1 with the outlet sampled temperature T2, adjusting the heater power to ensure that the temperature T2 reaches the temperature T1. This method presents two issues: 1. The initial water outlet temperature is uncertain, and the typical temperature sensor response time is 5-8 seconds, meaning the temperature in the first 5-8 seconds of a cup of water cannot be controlled. 2. The water tank temperature is close to the ambient temperature, resulting in a significant difference in inlet water temperature between winter and summer. The outlet water dissipates energy more rapidly in the air, resulting in lower outlet water temperatures in winter and higher temperatures in summer. These factors make it difficult for existing instant milk mixers to maintain a temperature accuracy of ±5°C, which falls short of the high precision requirement of 40-55°C for infant milk mixers.

[0004] Therefore, the traditional instant milk mixer still needs improvement. Summary of the Invention

[0005] The purpose of the present invention is to address the defects of the existing technology and provide a high-precision temperature-controlled instant milk mixer and a method for controlling the temperature of the instant milk mixer, so as to achieve accurate temperature control with an accuracy of up to plus or minus 3 degrees Celsius between the outlet water temperature and the set temperature, thereby meeting the use requirements of precise water outlet temperature.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: a temperature control method of an instant hot milk mixer, wherein the instant hot milk mixer is equipped with an inlet water temperature sensor and an outlet water temperature sensor, and comprises the following steps:

[0007] Step 1: The control unit collects the set temperature T1, the water inlet temperature T2, the water outlet temperature T3, and the cavity volume V1 of the instant heater in the instant milk maker;

[0008] Step 2: The control unit calculates the heating power of the instant heater when it is started according to the water inlet temperature T2 and the water outlet temperature T3, so that the water outlet is at the set temperature T1 at the first time.

[0009] Furthermore, the step 2 is specifically as follows:

[0010] S1. The control unit calculates the mass of water contained in the cavity of the instantaneous heater, M = ρ * V1, where M represents the mass of water and ρ represents the density of water;

[0011] S2. The control unit calculates the energy required to heat the water to the set temperature T1: Q1 = C * M * (T1 – T2), where Q1 represents the energy required to heat the water in the chamber and C represents the heat capacity ratio of the water.

[0012] S3. Calculate the initial heating power P1, P1 = Q1 / (t *η) = C *ρ * V1 *(T1 – T2) / (t *η), where η represents the heating conversion efficiency of the instant heater; t represents the heating time;

[0013] S4. Compare the set temperature T1 and the water outlet temperature T3, and fine-tune the starting heating power.

[0014] Furthermore, in step S3, the heating conversion efficiency η of the instant heater is set to 0.7-0.95; or, the heating time t is set to 1s-3s.

[0015] Furthermore, the step S4 is specifically as follows: comparing the set temperature T1 and the outlet water temperature T3;

[0016] If the set temperature T1> the outlet water temperature T3, the initial heating power will increase by ∆P1.

[0017] ∆P1 = C *ρ * V1 * (T1 – T3) / (t *η) * K1, K1 represents the environmental correction coefficient, which is used to make corresponding compensation based on the environment determined by the inlet water temperature sampling;

[0018] If the set temperature T1 is lower than the outlet water temperature T3, the initial heating power will be reduced by ∆P2.

[0019] ∆P2 = C *ρ * V1 * (T3 – T1) / (t *η) * K2, where K2 represents the environmental correction factor. The environment is judged and compensated accordingly based on the inlet water temperature sampling.

[0020] Furthermore, the value range of K1 is: when T2<10℃, K1=1.2-1.3; when T2<25℃, K1=1.1-1.2; when T2>25℃, K1=1; or, the value range of K2 is: when T2<10℃, K2=0.9--1; when T2<25℃, K2=1.0-1.1; when T2>25℃, K2=1.

[0021] The present invention also discloses a high-precision temperature-controlled instant hot milk mixer, comprising a control unit and an operating unit, a display unit, an instant hot heater, a water tank, a water pump, an inlet water temperature sensor and an outlet water temperature sensor respectively connected to the control unit; the water tank, water inlet, water pump, instant hot heater and water outlet are connected in sequence, and the water inlet and water outlet are respectively provided with the inlet water temperature sensor and the outlet water temperature sensor; the inlet water temperature sensor and the outlet water temperature sensor respectively collect the inlet water temperature and the outlet water temperature, the operating unit is used for the user to set the set temperature for heating requirements, the display unit is used for information display, and the control unit obtains the heating power when the instant hot heater is started according to the inlet water temperature, the outlet water temperature and the set temperature, so that the water discharged at the first time is the set temperature.

[0022] Furthermore, the control unit is connected to the instant heater via a heating unit driving circuit.

[0023] Furthermore, the control unit is connected to the water pump via a water pump drive circuit.

[0024] Furthermore, the water pump drive circuit includes a MOS tube Q1, a transistor Q2, a fixed resistor R4, and a fixed resistor R6. The drain, gate, and source of the MOS tube Q1 are respectively connected to the working power supply, the collector of the transistor Q2, and the water pump. A fixed resistor R4 is also connected between the collector of the transistor Q2 and the working power supply. The base of the transistor Q2 and the emitter of the transistor Q2 are respectively connected to the fixed resistor R6 and ground.

[0025] Furthermore, the water inlet temperature sensor or the water outlet temperature sensor includes a fixed resistor, a thermistor and a capacitor, one end of the fixed resistor is connected to the driving power supply, the other end of the fixed resistor is connected to the parallel thermistor and one end of the capacitor, and the other end of the parallel thermistor and capacitor is grounded.

[0026] By adopting the technical solution of the present invention, the beneficial effects of the present invention are as follows: by introducing a water inlet temperature sensor to sample the temperature, and adopting an algorithm to calculate that the outlet water can adapt to the environment, when starting heating, the initial heating power can be calculated based on the water inlet temperature. During the process, the correction power is calculated by the water inlet temperature, the water outlet temperature, and the set temperature to achieve precise temperature control; the instant milk mixer composed of a simple structural setting is safe and reliable to use, and meets the user's needs for accurate control of the milk mixing temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a three-dimensional diagram of a high-precision temperature-controlled instant hot milk mixer;

[0028] Figure 2 It is a cross-sectional view of a high-precision temperature-controlled instant hot milk mixer;

[0029] Figure 3 This is a control principle diagram of a high-precision temperature-controlled instant milk mixer;

[0030] Figure 4 The present invention is a flow chart of a method for controlling the temperature of an instant milk mixer;

[0031] Figure 5 The present invention is a diagram of the implementation process of the temperature control method of the instant milk mixer.

[0032] In the figure, 1 is a control unit, 2 is a water inlet temperature sensor, 3 is a water outlet temperature sensor, 4 is a power supply unit, 5 is a water pump drive circuit, 6 is an instant heater, 7 is an operating unit, 8 is a display unit, 9 is a water pump, 10 is a handle, 11 is a base, 12 is a water inlet, 13 is a water outlet, and 14 is a water tank. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described below by specific embodiments to make the present invention clearer and more understandable. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the various details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, in the case of no conflict, the features in the following embodiments and embodiments can be combined with each other.

[0034] like Figure 4 As shown, this embodiment relates to a temperature control method for an instant hot milk mixer, which is equipped with an inlet water temperature sensor 2 and an outlet water temperature sensor 3, and includes the following steps:

[0035] Step 1: The control unit collects the set temperature T1, the water inlet temperature T2, the water outlet temperature T3, and the cavity volume V1 of the instant heater in the instant milk maker;

[0036] Step 2: The control unit calculates the heating power of the instant heater when it is started according to the water inlet temperature T2 and the water outlet temperature T3, so that the water outlet is at the set temperature T1 at the first time.

[0037] Specifically, the control unit 1 uses the user-entered set temperature T1 via the user-operated operation unit 7 (i.e., various function buttons) and display unit 8 (displaying various parameters) of the high-precision temperature-controlled instant milk mixer. The control unit 1 obtains the inlet water temperature T2 through sampling by the inlet water temperature sensor 2, and the outlet water temperature T3 through sampling by the outlet water temperature sensor 3. The chamber volume V1 of the instant heater in this embodiment is 1. Because the inlet water temperature T2 can be sampled, the inlet water temperature sensor 2 is always at the water inlet (where water is present), eliminating the 5-8 second sensor lag issue. Furthermore, the control unit 1 calculates the heating power at startup based on the inlet water temperature, the user-set temperature, and the chamber volume of the instant heater, ensuring that the water immediately outflows at the user-set temperature T1.

[0038] The calculation method is as follows:

[0039] (1) Calculate the water mass that the heater cavity can hold:

[0040] M=ρ* V1, M represents the mass of water, ρ represents the density of water (physical parameter);

[0041] (2) Calculate the energy required to reach the set temperature:

[0042] Q1 = C * M * (T1–T2), Q1 represents the energy required to heat a certain volume of water, C: heat capacity ratio of water (physical parameter);

[0043] (3) Calculate the initial heating power P1:

[0044] P1= Q1 / (t *η), η represents the conversion efficiency of the heater heating system (0.7-0.95, depending on the product system debugging setting), t represents the heating time (the product defines the water discharge time, 1s-3s);

[0045] (4) Substitute the formulas in (1) and (2) into step (3) to obtain the starting heating power:

[0046] P1 = C *ρ * V1 * (T1–T2) / (t *η).

[0047] After entering the formal operation for 5 s (the water outlet temperature sampling sensor can accurately sample the water outlet temperature), in this embodiment, the heating power ∆P is finely adjusted based on the temperature difference between the water outlet temperature sampled by the water outlet temperature sampling sensor and the set temperature.

[0048] The calculation method of the finely adjusted heating power ∆P is as follows:

[0049] Judge that if T1 > T3, the heating power increases by ∆P1:

[0050] ∆P1 = C * ρ * V1 * (T1 – T3) / (t * η) * K1

[0051] K1: Environmental correction coefficient. Based on the sampling of the inlet water temperature, judge the replacement parts and make corresponding compensations.

[0052] Value range: When T2 < 10 °C, K1 = 1.2 - 1.3; when T2 < 25 °C, K1 = 1.1 - 1.2; when T2 > 25 °C, K1 = 1.

[0053] Judge that if T1 < T3, the heating power is reduced by ∆P2:

[0054] ∆P2 = C * ρ * V1 * (T3 – T1) / (t * η) * K2

[0055] K2: Environmental correction coefficient. Based on the sampling of the inlet water temperature, judge the replacement parts and make corresponding compensations;

[0056] Value range: When T2 < 10 °C, K2 = 0.9 - 1; when T2 < 25 °C, K2 = 1.0 - 1.1; when T2 > 25 °C, K2 = 1.

[0057] Through the above calculations and cyclic control, the accuracy of the water outlet temperature of the instant hot water dispenser of the present invention can be controlled within ±3 °C.

[0058] The implementation process of this method is as Figure 5 shown. When the power of the high-precision temperature-controlled instant hot water dispenser is started, the control unit of the control unit is initialized, the inlet water temperature of the water inlet, the water outlet temperature of the water outlet, and the set temperature are scanned and read for user operations, and then the heating is started, the starting heating power is calculated, the water pump is started after the heating delay setting time, and it is judged whether the water outlet temperature is higher or lower than the set temperature to determine whether to increase or decrease the starting heating power, and then the heating is carried out. When the preset temperature is reached, the heating is stopped.

[0059] As Figure 1-3As shown, this embodiment also provides a high-precision temperature-controlled instant hot milk mixer, comprising a control unit 1 and an operating unit 7, a display unit 8, an instant hot heater 6, a water tank 14, a water pump 9, an inlet water temperature sensor 2, and an outlet water temperature sensor 3, each connected to the control unit. The water tank 14, the water inlet, the water pump 9, the instant hot heater 6, and the water outlet 13 are sequentially connected. The water inlet 12 and the water outlet 13 are respectively provided with the inlet water temperature sensor 2 and the outlet water temperature sensor 3. The inlet water temperature sensor 2 and the outlet water temperature sensor 3 respectively collect the inlet water temperature and the outlet water temperature. The operating unit 7 is used for the user to set the set temperature for heating requirements. The display unit 8 is used for information display. The control unit 1 calculates the heating power of the instant hot heater when it is activated based on the inlet water temperature, the outlet water temperature, and the set temperature, so that the water discharged immediately is the set temperature. When in use, a container such as a cup or bottle containing milk powder is placed at the water outlet, and hot water of the preset temperature flows from the water outlet of the high-precision temperature-controlled instant hot milk mixer into the container for milk powder brewing.

[0060] Because the entire high-precision temperature-controlled instant milk mixer is relatively cumbersome to move and access, the water tank is designed to be detachably mounted on the overall housing of the milk mixer. The bottom of the water tank is connected to the water inlet, making it easy to use the water tank alone to access water. A handle 10 is also provided on the water tank to facilitate lifting and moving the water tank when filled with water. A base 11 is also provided on one side of the water outlet 1 for placing containers such as milk bottles to receive water from the outlet. The base 11 is equipped with a drain trough and drain plate.

[0061] The control unit (i.e., the control unit) of this milk mixer is connected to the water pump via a water pump drive circuit. This water pump drive circuit includes a MOS transistor Q1, a transistor Q2, a fixed resistor R4, and a fixed resistor R6. The drain, gate, and source of the MOS transistor Q1 are connected to a power supply, the collector of the transistor Q2, and the water pump, respectively. A fixed resistor R4 is also connected between the collector of the transistor Q2 and the power supply. The base and emitter of the transistor Q2 are connected to the fixed resistor R6 and ground, respectively.

[0062] The water inlet temperature sensor or the water outlet temperature sensor of this embodiment includes a fixed resistor, a thermistor and a capacitor. One end of the fixed resistor is connected to a driving power supply, and the other end of the fixed resistor is connected to one end of the thermistor and the capacitor in parallel. The other ends of the thermistor and the capacitor in parallel are grounded.

[0063] The control unit of the milk mixer is connected to the instant heating heater via a heating unit drive circuit. The heating unit drive circuit includes a capacitor C4, a capacitor C5, a fixed resistor R8, a fixed resistor R9, a fixed resistor R10, a fixed resistor R11, a transistor Q3, and a bidirectional trigger diode Q4. One end of the capacitor C5 and the fixed resistor R8 connected in parallel is connected to the first pin of the bidirectional trigger diode Q4 and an AC power supply, respectively. The other end of the capacitor C5 and the fixed resistor R8 connected in parallel is simultaneously connected to the third pin of the bidirectional trigger diode Q4 and one end of the fixed resistor R9. The second pin of the bidirectional trigger diode Q4 is connected to the instant heating heater. The other end of the fixed resistor R9 is connected to the collector of the transistor Q3. One end of the fixed resistor R11 and the capacitor C4 connected in parallel is connected to the base of the transistor Q3 and one end of the fixed resistor R10, respectively. The emitter of the transistor Q3, the fixed resistor R11, and the capacitor C4 connected in parallel are grounded.

[0064] In this embodiment, the operating unit 7 is implemented using a knob, button, or touch screen. For example, the + and - keys are used to increase or decrease the set temperature. The display unit 8 is a screen that displays various temperature and switch status information. The power supply unit 4 uses a voltage converter to convert 220V AC power to the 5V and 12V voltages required for the operation of various units or circuits. The control unit 1 can also use various processors with information and data processing capabilities, such as a single-chip microcomputer.

[0065] It should be noted that the diagrams provided in the above embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the diagrams only show components relevant to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be varied at will, and the component layout may be more complex. The present invention may also include many other equivalent embodiments. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this disclosure shall be included within the scope of protection of this disclosure.

Claims

1. A temperature control method for an instant hot milk mixer, characterized in that: The instant-heating milk warmer is equipped with an inlet water temperature sensor and an outlet water temperature sensor, and comprises the following steps: Step 1: The control unit collects the set temperature T1 set by the user, the inlet water temperature T2 at the water inlet, and the outlet water temperature T3 at the water outlet, and the cavity volume V1 of the instant heater in the instant-heating milk warmer; Step 2: The control unit calculates the heating power when the instant heater starts according to the inlet water temperature T2 and the outlet water temperature T3, so that the water discharged for the first time is the set temperature T1; The specific content of the said Step 2 is as follows: S1: The control unit calculates the mass of water contained in the cavity of the instant heater, M = ρ * V1, where M represents the mass of water and ρ represents the water density; S2: The control unit calculates the energy required to heat to the set temperature T1, Q1 = C * M * (T1–T2), where Q1 represents the energy required to heat the water in the heating cavity and C represents the specific heat capacity ratio of water; S3: Calculate the starting heating power P1, P1 = Q1 / (t * η) = C * ρ * V1 * (T1–T2) / (t * η), where η represents the heating conversion efficiency of the instant heater; t represents the heating time; S4: Compare the magnitudes of the set temperature T1 and the outlet water temperature T3, and finely adjust the starting heating power; The specific content of the said Step S4 is: Compare the magnitudes of the set temperature T1 and the outlet water temperature T3; If the set temperature T1 > the outlet water temperature T3, the starting heating power is increased by ΔP1, ΔP1 = C * ρ * V1 * (T1–T3) / (t * η) * K1, where K1 represents the environmental correction coefficient, and corresponding compensation is made according to the judgment of the environment based on the sampling of the inlet water temperature; If the set temperature T1 < the outlet water temperature T3, the starting heating power is decreased by ΔP2, ΔP2 = C * ρ * V1 * (T3–T1) / (t * η) * K2, where K2 represents the environmental correction coefficient, and corresponding compensation is made according to the judgment of the environment based on the sampling of the inlet water temperature.

2. The temperature control method of an instant hot milk mixer according to claim 1, characterized in that: In the said Step S3, the heating conversion efficiency η of the instant heater takes a value of 0.7 - 0.95; or, the heating time t takes a value of 1 s - 3 s.

3. The temperature control method of an instant hot milk mixer according to claim 1, characterized in that: The value range of the said K1 is: when T2 < 10°C, K1 = 1.2 - 1.3; when 10°C < T2 < 25°C, K1 = 1.1 - 1.2; when T2 > 25°C, K1 = 1; Or, the value range of the said K2 is: when T2 < 10°C, K2 = 0.9 - 1; when 10°C < T2 < 25°C, K2 = 1.0 - 1.1; when T2 > 25°C, K2 = 1.

4. A high-precision temperature-controlled instant milk mixer, characterized in that: Adopt the instant-heating milk warmer temperature control method as described in any one of Claims 1 - 3, which comprises a control unit and an operation unit, a display unit, an instant heater, a water tank, a water pump, an inlet water temperature sensor and an outlet water temperature sensor respectively connected to the control unit; the water tank, the water inlet, the water pump, the instant heater, and the water outlet are connected in sequence, and the inlet water temperature sensor and the outlet water temperature sensor are respectively arranged at the water inlet and the water outlet; The water inlet temperature sensor and the water outlet temperature sensor respectively collect the water inlet temperature and the water outlet temperature. The operating unit is used for the user to set the set temperature for heating requirements. The display unit is used for information display. The control unit calculates the heating power of the instant heater when it is started based on the water inlet temperature, the water outlet temperature and the set temperature, so that the water outlet is the set temperature at the first time.

5. The high-precision temperature-controlled instant hot milk mixer according to claim 4, characterized in that: The control unit is connected to the instant heater via a heating unit driving circuit.

6. The high-precision temperature-controlled instant hot milk mixer according to claim 4, characterized in that: The control unit is connected to the water pump via a water pump driving circuit.

7. The high-precision temperature-controlled instant hot milk mixer according to claim 6, characterized in that: The water pump drive circuit includes a MOS tube Q1, a transistor Q2, a fixed resistor R4, and a fixed resistor R6. The drain, gate, and source of the MOS tube Q1 are respectively connected to a working power supply, a collector of the transistor Q2, and a water pump. A fixed resistor R4 is also connected between the collector of the transistor Q2 and the working power supply. The base of the transistor Q2 and the emitter of the transistor Q2 are respectively connected to the fixed resistor R6 and ground.

8. The high-precision temperature-controlled instant hot milk mixer according to claim 4, characterized in that: The water inlet temperature sensor or the water outlet temperature sensor includes a fixed resistor, a thermistor and a capacitor. One end of the fixed resistor is connected to a driving power supply, and the other end of the fixed resistor is connected to one end of the thermistor and the capacitor in parallel. The other ends of the thermistor and the capacitor in parallel are grounded.

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