A digitalized steamer and a control method thereof

Abstract

The present application relates to a kind of digital steamer, including cavity, and the steam output device and steamer control device being arranged outside cavity, the inside of the cavity is equipped with second pressure sensor, to detect steamer air pressure, first air inlet is equipped on the inner wall of the cavity;The steam output device includes liquid pump and heating body, the liquid pump is extracted from water tank by first pipeline and is sent to the heating body, the heating body converts the liquid water into steam, is sent to the cavity by third pipeline being connected with the first air inlet, steam valve is equipped on the third pipeline, first temperature sensor is equipped in the first pipeline or the container, to detect the initial temperature of liquid water;The steamer control device is calculated according to the steamer air pressure and initial temperature, and the water flow of the liquid pump is extracted, and it is extracted based on the water flow to extract liquid water.The humidity and air pressure of the steamer can be accurately controlled by the present application.

Description

Technical Field

[0001] This invention relates to the field of digital steam oven technology, and in particular to a digital steam oven and its control method. Background Technology

[0002] A steam oven is a piece of equipment used in product processing. It's widely used not only in daily cooking but also in the textile industry. Currently, precise moisture control in textile post-processing steam ovens has a significant impact on textiles. First, precise moisture control ensures that textiles achieve the desired results during heat setting. Appropriate moisture levels help fibers better maintain their required shape and size under high temperatures and ensure strong fiber bonds. Too much or too little moisture can lead to unsatisfactory heat setting results. Second, some textiles shrink during steam treatment, and precise moisture control can regulate the shrinkage rate. By controlling the moisture content, precise control of textile dimensions can be achieved to meet product design and requirements. Precise moisture control can also affect the texture and feel of fibers. In some fibers, appropriate moisture can make them soft and elastic, improving the feel and comfort of the textile. Precise moisture control allows adjustment of fiber moisture content, thereby adjusting the texture and feel of the textile. Finally, precise moisture control can improve the processing efficiency of textile post-processing steam ovens and reduce energy consumption. Precise moisture control reduces processing time and energy waste, increasing production efficiency and saving costs. Currently, moisture control in textile post-processing steamers mainly relies on traditional manual operation and experience-based judgment, leading to problems such as inaccurate moisture content and unstable processing results. Furthermore, the required moisture content varies depending on the type of textile being processed, and atmospheric pressure differs across the country; for example, the lower atmospheric pressure in Tibet due to its high altitude may cause water to boil slowly. In addition, the increasing demand for multifunctional products necessitates more intelligent steamers. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a digital steam oven and its control method, which can accurately control the humidity and air pressure of the steam oven.

[0004] The technical solution adopted by this invention to solve its technical problem is as follows: A digital steam oven is provided, comprising a cavity serving as a steam chamber, and a steam output device and a steam oven control device disposed outside the cavity. A second pressure sensor is provided inside the cavity to detect the steam oven pressure. A first air inlet is provided on the inner wall of the cavity. The steam output device includes a liquid pump and a heating element. The liquid pump draws liquid water from a water tank through a first pipe and delivers it to the heating element. The heating element converts the liquid water into steam and delivers the steam into the cavity through a third pipe connected to the first air inlet. A steam valve is provided on the third pipe to control the steam delivery status. A first temperature sensor is provided inside the first pipe or the container to detect the initial temperature of the liquid water. The steam oven control device calculates the pumping flow rate of the liquid pump based on the steam oven pressure and the initial temperature, and controls the liquid pump to use the pumping flow rate to pump water.

[0005] Furthermore, the pumping flow rate Calculated using the heat conservation formula:

[0006]

[0007] in, This represents the operating time of the heating element. Represents the power of the heating element. This represents the thermal efficiency of the heating element. Represents the specific heat of water. Represents the boiling point of water. Represents the initial temperature. The enthalpy of vaporization of water. Represents the steam moisture content. This represents the density of water.

[0008] Furthermore, when the steam chamber pressure is not standard atmospheric pressure:

[0009] Boiling point of water Calculated using the boiling point formula

[0010]

[0011] enthalpy of vaporization of water It is calculated using the enthalpy of vaporization formula.

[0012]

[0013] in, This represents the air pressure in the steam oven.

[0014] Furthermore, the boiling point formula and the enthalpy of vaporization formula are obtained by fitting data obtained from a lookup table.

[0015] Furthermore, a pressure relief valve is also provided on the inner wall of the cavity.

[0016] The technical solution adopted by this invention to solve its technical problem is: to provide a control method for a digital steam oven, applied to the digital steam oven described above, comprising the following steps:

[0017] Ensure the steam valve is in the open position;

[0018] Obtain the steam chamber pressure;

[0019] The boiling point of water is calculated using the boiling point formula based on the steam chamber pressure, and the enthalpy of water is calculated using the enthalpy of evaporation formula.

[0020] Obtain the initial temperature of the liquid water;

[0021] The pumping flow rate of the liquid pump is calculated using the heat conservation formula based on the steam chamber pressure, initial temperature, boiling point, and enthalpy of evaporation.

[0022] The pump is controlled to pump water using the specified pumping flow rate.

[0023] Furthermore, after the step of controlling the liquid pump to pump water using the specified pumping flow rate, the method further includes adjusting the humidity of the steam chamber by adjusting the pumping time of the liquid pump.

[0024] Furthermore, it also includes the step of adjusting the steam chamber pressure by adjusting the power of the heating element based on the water pumping flow rate, including:

[0025] Set the desired operating air pressure of the steam oven, and set the desired air pressure range based on the desired operating air pressure;

[0026] Real-time monitoring of steam oven pressure to obtain real-time steam oven pressure;

[0027] When the real-time steam chamber pressure is higher or lower than the desired pressure range, the real-time steam chamber pressure is adjusted to the desired pressure range by adjusting the power of the heating element.

[0028] Furthermore, the power of the heating element is calculated using the heat conservation formula, boiling point formula, and enthalpy of vaporization formula.

[0029] Beneficial effects

[0030] By adopting the above-mentioned technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0031] (1) The present invention collects relevant data in real time by setting temperature and pressure sensors in the digital steam oven system device, and calculates the water flow rate by substituting the above data into the law of conservation of energy, thereby realizing precise control of the humidity of the steam oven;

[0032] (2) The present invention can automatically adjust the humidity and pressure of the steam box according to the parameters set by the user without manual intervention, realizing intelligent automatic control function, improving the convenience, safety and production efficiency of use. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the system structure according to the first embodiment of the present invention;

[0034] Figure 2 This is a linear relationship between atmospheric pressure and the boiling point of water when the atmospheric pressure is in the range of 0.1MPa to 0.2MPa.

[0035] Figure 3 This is a linear relationship between atmospheric pressure and the enthalpy of vaporization of water when the atmospheric pressure is in the range of 0.1MPa to 0.2MPa.

[0036] Figure 4 This is a flowchart of the second embodiment of the present invention. Detailed Implementation

[0037] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0038] The first embodiment of the present invention relates to a digital steam oven, such as... Figure 1 As shown, the device includes a cavity serving as a steam chamber, and a steam output device and a steam chamber control device disposed outside the cavity. A second pressure sensor is installed inside the cavity to detect the steam chamber pressure, and a first air inlet is provided on the inner wall of the cavity. In some embodiments, a third temperature sensor is also installed inside the cavity to detect the temperature inside the steam chamber, and a pressure relief valve may also be installed on the inner wall of the cavity.

[0039] The steam output device includes a liquid pump and a heating element. One end of the liquid pump is connected to a container holding pure water via a first pipe, and the other end is connected to the first liquid inlet of the heating element via a second pipe. The first steam outlet of the heating element is connected to one end of a steam valve via a third pipe, and the other end of the steam valve is connected to the first air inlet via a fourth pipe. A first temperature sensor is installed inside the first pipe or container to detect the initial temperature of the pure water. In some embodiments, a first pressure sensor is also installed inside the third pipe, near the first steam outlet, to monitor the internal air pressure in real time. Furthermore, a second temperature sensor can be installed inside the heating element near the first steam outlet to monitor the temperature of the output steam. A water level sensor and a UV lamp can be installed in the container holding the pure water. The water level sensor alerts the user to replace the pure water when the water level reaches the bottom, and the UV lamp is used to disinfect and sterilize the pure water. Some steam oven systems may also include a hot water valve to control the hot water supply.

[0040] The steam chamber control device calculates the pumping flow rate of the liquid extraction pump based on the steam chamber's air pressure and initial temperature using the energy conservation formula. Based on this flow rate, it controls the pump to extract a certain volume of pure water, which is then heated by the heating element to generate steam, which is then delivered to the steam chamber. The specific formula is as follows:

[0041] in, This indicates the amount of heat released by the heating element in the device. This indicates the thermal efficiency of the heating element. Based on the efficiency ratings of heating elements currently on the market, the value is generally between 80% and 95%. This represents the heat absorbed by the water in the heating element, and is divided into two parts. This represents the amount of heat used to heat liquid water. This indicates the amount of heat carried away by water vapor.

[0042] The above formula can be further specified as follows:

[0043]

[0044] In the formula, For working hours, The boiling point of water (at standard atmospheric pressure). ), The raw water temperature is [temperature value], and the heating element power is [power value]. thermal efficiency Pumping flow rate Steam moisture content (The proportion of liquid water in the steam), the density of water is... The specific heat of water is enthalpy of vaporization of water (The amount of heat required for 1 kg of water to evaporate at its boiling point under standard atmospheric pressure) ).

[0045] The pumping flow rate of the water pump can be calculated using the above formula, which is a formula relating to power, pressure, temperature, and the evaporation rate of water. Based on the set water demand, it can calculate the working time at that pumping flow rate and control the water pump to perform pumping operations.

[0046] like Figure 2 and Figure 3 As shown, when the pressure p is not at standard atmospheric pressure, the boiling point of water is... enthalpy of vaporization of water It is variable. The pressure range used in steam ovens is usually 0.1MPa to 0.2MPa. After consulting tables and conducting data analysis, it can be seen that within this atmospheric pressure range, the pressure, the boiling point of water, and the enthalpy of vaporization of water can be approximately linearly related. After data fitting, the relevant formula can be obtained.

[0047] The formula relating pressure and the boiling point of water is: Where Y1 represents the boiling point and X represents the local atmospheric pressure.

[0048] The formula relating pressure and the enthalpy of vaporization of water is: Where Y2 represents the enthalpy of water evaporation, and X represents the local atmospheric pressure.

[0049] The boiling point and enthalpy of vaporization of water can be calculated using the above formulas. Substituting these values ​​into the pumping flow rate calculation formula yields the pumping flow rate of the water pump, thus enabling precise control.

[0050] The second embodiment of the present invention relates to a control method for a digital steam oven, applied to the digital steam oven in the first embodiment, such as... Figure 4 As shown, the specific steps include:

[0051] Ensure the steam valve is in the open position;

[0052] Obtain the steam chamber pressure;

[0053] Based on the steam chamber pressure, the boiling point of water is calculated using the boiling point formula, and the enthalpy of evaporation of water is calculated using the enthalpy of evaporation formula.

[0054] Obtain the initial temperature of the liquid water;

[0055] The pumping flow rate of the liquid pump is calculated using the heat conservation formula based on the steam chamber pressure, initial temperature, boiling point, and enthalpy of evaporation.

[0056] The pump is controlled to pump water using the specified pumping flow rate.

[0057] Among them, the boiling point formula and the enthalpy of vaporization formula can be obtained by looking up relevant data in tables and then fitting the data.

[0058] The following section uses the textile post-processing process as an example to further explain the above method.

[0059] During textile post-processing, the liquid pump and heating element operate, and the steam valve is open. Let the heating element power be P, the thermal efficiency be η, the pump flow rate be u, the steam water content be k (the proportion of liquid water in the steam), and the water density be ρ = 1.0. 103 kg / m³, specific heat of water is C = 4.2 103 J / (kg·K), heat of vaporization of water H=2.256 106 J / kg (the amount of heat required to evaporate 1 kg of water at its boiling point under standard atmospheric pressure). This can be obtained from Qaddition·η = Qabsorption.

[0060] In the formula, t is the working time, Ta is the boiling point of water (Ta = 100° at standard atmospheric pressure), and T0 is the initial temperature of pure water.

[0061] Eliminating time t from both sides of the formula, we get

[0062]

[0063] Among them, the heating element power P or steam water content k are preset parameters, the raw water temperature T0 is measured by temperature sensor 1, and the thermal efficiency η is determined by the heating element itself. The pumping flow rate u of the pumping pump can be calculated according to the above formula.

[0064] For example, if the heating power of a steam oven for processing a certain textile material is P=1000W, the steam water content is k=0.5, the raw water temperature is T0=25°, Ta=100°, and the thermal efficiency is η=90%, then by substituting into the formula, we can get u=4.95*10-7m3 / s=29.7mL / min.

[0065] If the vapor pressure p is not standard atmospheric pressure, and is measured by pressure sensor 2, then

[0066] T(p) and H(p) can be calculated using the boiling point formula and the enthalpy of vaporization formula.

[0067] For example, p is 1.5 atmospheres, or 0.15 MPa. Using the formula, we can obtain T(0.15 MPa) and H(0.15 MPa) as 110.71°C and 2692.679 KJ·Kg⁻¹, respectively. The heating power of the steam oven for processing a certain textile material is P=1000W, the steam water content is k=0.5, the raw water temperature is T0=25°, Ta=110.71°, and the thermal efficiency is η=90%. Substituting these values ​​into the formula, we can obtain u=22.4 ml / min.

[0068] After calculating the water flow rate, the steam oven control device can control the liquid pump to pump water at that flow rate. By adjusting the working time of the liquid pump, the amount of water entering the steam oven can be adjusted, thereby regulating the humidity of the steam oven.

[0069] In some implementations, a second pressure sensor can be used to monitor the steam chamber pressure in real time to obtain the real-time steam chamber pressure, and the power of the heating element can be adjusted according to the water pumping flow rate to keep the real-time pressure near the preset pressure value.

[0070] According to the law of conservation of energy, steam quantity, inlet water flow rate, power, and pressure are corresponding. That is, if the heating power and steam quantity are fixed, the corresponding pressure can be calculated using the formula. Pressure, temperature, and enthalpy of vaporization are also fixed; if the pressure is fixed, the temperature is fixed because there is a linear relationship between pressure and temperature, and also a linear relationship between pressure and enthalpy of vaporization. During the operation of the steam oven, the pressure changes. A pressure value (P ± ᴧP) is set; exceeding or falling below this range will activate the system. Based on this formula, while ensuring a constant steam quantity, adjusting the power of the heating element is sufficient to regulate the steam oven pressure.

[0071] Specifically, the following steps are included:

[0072] Set the desired working air pressure of the steam oven, and set the desired air pressure range based on the desired working air pressure;

[0073] Real-time monitoring of steam oven pressure to obtain real-time steam oven pressure;

[0074] When the real-time steam chamber pressure is higher or lower than the desired pressure range, the real-time steam chamber pressure is adjusted to within the desired pressure range by adjusting the power of the heating element. (Heating element power) It can be calculated using the heat conservation formula, the boiling point formula, and the enthalpy of vaporization formula.

[0075] In summary, the present invention can achieve precise control of humidity and pressure in the steam oven, thereby enabling accurate control of moisture content during textile processing, improving heat setting effect, shrinkage control, dyeing and printing effects, as well as fiber texture and hand feel.

Claims

1. A digital steam oven, characterized in that, The device includes a cavity serving as a steam chamber, and a steam output device and a steam chamber control device disposed outside the cavity. The cavity is equipped with a second pressure sensor to detect the steam chamber pressure, and a first air inlet is located on the inner wall of the cavity. The steam output device includes a liquid pump and a heating element. The liquid pump draws liquid water from a water tank through a first pipe and delivers it to the heating element. The heating element converts the liquid water into steam and delivers the steam into the cavity through a third pipe connected to the first air inlet. The third pipe is equipped with a steam valve to control the steam delivery status. A first temperature sensor is located inside the first pipe to detect the initial temperature of the liquid water. The steam chamber control device calculates the pumping flow rate of the liquid pump based on the steam chamber pressure and the initial temperature, controls the liquid pump to use the pumping flow rate, and adjusts the power of the heating element based on the pumping flow rate to keep the steam chamber pressure within a set desired pressure range. The pumping flow rate Calculated using the heat conservation formula: in, This represents the operating time of the heating element. Represents the power of the heating element. This represents the thermal efficiency of the heating element. Represents the specific heat of water. Represents the boiling point of water. Represents the initial temperature. The enthalpy of vaporization of water. Represents the steam moisture content. Represents the density of water; When the steam oven pressure is not standard atmospheric pressure: Boiling point of water Calculated using the boiling point formula enthalpy of vaporization of water It is calculated using the enthalpy of vaporization formula. in, This represents the air pressure in the steam oven.

2. The digital steam oven according to claim 1, characterized in that, The boiling point formula and the enthalpy of vaporization formula are obtained by fitting data obtained from a lookup table.

3. A control method for a digital steam oven, characterized in that, The digital steam oven described in any one of claims 1-2 includes the following steps: Ensure the steam valve is in the open position; Obtain the steam chamber pressure; The boiling point of water is calculated using the boiling point formula based on the steam chamber pressure, and the enthalpy of evaporation of water is calculated using the enthalpy of evaporation formula. Obtain the initial temperature of the liquid water; The pumping flow rate of the liquid pump is calculated using the heat conservation formula based on the steam chamber pressure, initial temperature, boiling point, and enthalpy of evaporation. The pump is controlled to pump water using the specified pumping flow rate.

4. The control method according to claim 3, characterized in that, After the step of controlling the liquid pump to pump water using the specified pumping flow rate, the method further includes adjusting the humidity of the steam chamber by adjusting the pumping time of the liquid pump.

5. The control method according to claim 3, characterized in that, It also includes the step of adjusting the steam chamber pressure by adjusting the power of the heating element based on the water flow rate, including: Set the desired working air pressure of the steam oven, and set the desired air pressure range based on the desired working air pressure; Real-time monitoring of steam oven pressure to obtain real-time steam oven pressure; When the real-time steam chamber pressure is higher or lower than the desired pressure range, the real-time steam chamber pressure is adjusted to the desired pressure range by adjusting the power of the heating element.

6. The control method according to claim 5, characterized in that, The power of the heating element is calculated using the heat conservation formula, boiling point formula, and enthalpy of vaporization formula.

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