Drying control method and washing and drying all-in-one machine adopting same

Abstract

The invention discloses a drying control method and a washing and drying all-in-one machine adopting the same. The drying control method is characterized by comprising the following steps: 1, initializing setting; 2, operating at a first air volume m1; 3, the current temperature difference delta t1 of the air inlet and the air outlet is calculated; 4, judging whether delta t1 is smaller than or equal to a threshold temperature difference delta t0, and if so, executing the next step 5; if not, returning to the previous step 3; 5, reducing the air volume and operating at a second air volume m2; 6, the temperature difference delta t2 of the air inlet and the air outlet is calculated; 7, whether delta t2 is smaller than or equal to the threshold temperature difference delta t0 or not is judged, and if yes, the step 9 is executed; if not, executing the next step 8; 8, running at the first air volume m1 for the duration time t, and returning to the step 5; and 9, stopping drying. The method has the advantages that according to the heat exchange conservation principle, clothes drying is represented through the change difference of the in-out drum temperature difference value caused by air volume change and the original air volume in-out drum temperature difference value, accurate drying judgment can be achieved, implementation is easy and convenient, and the manufacturing cost is low.

Description

Technical Field

[0001] The present invention relates to a drying control method, in particular to a drying control method and a washer-dryer adopting the control method. Background Art

[0002] In the prior art, washer-dryers typically use temperature or weighting to determine if a device is dry, such as the Chinese invention patent with patent number ZL202111450588.7, "Clothing Dryness Determination Method, Device, and Clothing Treatment Device for Clothing Treatment Equipment," the Chinese invention patent application with application number 202211626761.9, "Clothing Drying Method, Device, Dryer, and Computer Storage Medium," and the Chinese invention patent application with application number 202110252144.6, "Clothing Drying Method, Device, Clothing Treatment Device, and Storage Medium." The temperature-based dryness determination method typically involves installing a temperature sensor at the outlet or between the inlet and outlet, detecting the outlet temperature or the temperature difference between the outlet and inlet. Dryness is determined when the temperature or temperature difference reaches a set threshold.

[0003] However, the above drying methods often have the following problems: 1. Small-weight clothes are over-dried, while large-weight clothes are not dried dry; 2. Regardless of the amount of clothes to be dried, the ambient temperature, or changes in the operating conditions of the compressor and fan, the same dryness judgment temperature or temperature difference threshold is used, resulting in misjudgment; 3. Weighing is used to judge dryness, but the weighing error is usually around 0.5kg, and the measurement accuracy is insufficient.

[0004] To sum up, the drying technology in the existing technology still has the above-mentioned problems. How to make clothes of different qualities and materials, under different ambient temperatures, not affected by the operating conditions of the compressor and fan, accurately judge the drying and obtain better drying effects has become a problem that needs to be solved urgently in the field of dryers. The existing drying technology needs to be further improved and perfected. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is to provide a drying control method with a simple detection method and the ability to effectively avoid misjudgment and make the detection results more accurate in response to the above-mentioned existing technical status.

[0006] The second technical problem to be solved by the present invention is to provide a washer-dryer that adopts the above-mentioned drying control method to achieve its operation in response to the above-mentioned existing technical status.

[0007] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a drying control method, characterized in that the drying control method includes the following steps:

[0008] Step 1: Start the program and initialize the settings;

[0009] Step 2: Adjust the air volume of the drying equipment to operate at the first air volume m1;

[0010] Step 3: Detect the current air inlet temperature and air outlet temperature, and calculate the current temperature difference between the air inlet and the air outlet as δt1;

[0011] Step 4: Determine whether the temperature difference δt1 in step 3 is less than or equal to the preset dry threshold temperature difference δt0. If yes, proceed to step 5; if not, return to step 3.

[0012] Step 5: Reduce the air volume of the drying equipment and operate at the second air volume m2;

[0013] Step 6: Detect the current air inlet temperature and air outlet temperature, and calculate the temperature difference between the current air inlet and air outlet as δt2;

[0014] Step 7: Determine whether the temperature difference δt2 in step 6 is less than or equal to the preset dry threshold temperature difference δt0. If so, proceed to step 9; if not, proceed to step 8.

[0015] Step 8: Increase the air volume of the drying equipment to operate at the first air volume m1 for a duration of t, and then return to step 5;

[0016] Step 9: Stop drying and the program ends.

[0017] To facilitate detection of change data and take into account drying efficiency, the relationship between the first air volume m1 and the second air volume m2 is preferably: m2 = K × m1, where K is the air volume adjustment coefficient and the value range of K is 0.5 to 0.9. If the air volume reduction is too small, that is, the value of K is too large, the temperature difference caused by the air volume change may be too small to be detected; while if the air volume reduction is too large, it may extend the drying time.

[0018] Considering that increasing the air volume is a dynamic process, in order to ensure that the air volume can ultimately be maintained at m1 and stable operation, as a preferred embodiment, the duration t in step 8 is in the range of 2 to 6 minutes. Setting the duration t can avoid fluctuations and instability in the air volume adjustment process.

[0019] Considering that increasing the air volume is a dynamic process, in order to save time, the increase of the air volume is stopped when the air volume increases to an appropriate size. As another preferred embodiment, the time to stop increasing the air volume can be determined by judging the temperature difference. Specifically, the step eight can also be implemented by the following method:

[0020] Step 8-1, increase the air volume of the drying equipment;

[0021] Step 8-2: Detect the current air inlet temperature and air outlet temperature, and calculate the current temperature difference between the air inlet and the air outlet as δt3;

[0022] Step 8-3: Determine whether the temperature difference δt3 in step 8-2 is less than or equal to the dry threshold temperature difference δt0. If so, the air volume is considered to have reached the maximum, and the process returns to step 5. If not, the air volume is increased again, and step 8-3 is repeated. When the temperature difference is detected to be less than or equal to the preset threshold, the air volume increase is stopped and then decreased again. This alternating process of increasing and decreasing the air volume allows the clothes in the washing drum to be thoroughly dried.

[0023] In order to reduce measurement errors and improve detection accuracy, preferably, the air inlet temperature and the air outlet temperature in step three are detected in real time by an air inlet temperature sensor arranged at the air inlet and an air outlet temperature sensor arranged at the air outlet, respectively.

[0024] Taking into account the stability of equipment operation, as a further preferred embodiment, the frequency of real-time detection of the inlet air temperature sensor and the outlet air temperature sensor is once every 1 to 10 seconds.

[0025] In order to reduce measurement errors and improve detection accuracy, preferably, the air inlet temperature and the air outlet temperature in step 6 are respectively detected in real time by an air inlet temperature sensor provided at the air inlet and an air outlet temperature sensor provided at the air outlet. The frequency of the real-time detection of the air inlet temperature sensor and the air outlet temperature sensor is once every 1 to 10 seconds.

[0026] The technical solution adopted by the present invention to solve the above-mentioned second technical problem is: a washer-dryer, including an air inlet and an air outlet, characterized in that: the washer-dryer adopts the drying control method as described above to implement the drying program.

[0027] In order to obtain the best measurement effect and facilitate measurement, the air inlet is provided with an air inlet temperature sensor for detecting the air inlet temperature, and the air outlet is provided with an air outlet temperature sensor for detecting the air outlet temperature.

[0028] Compared with the prior art, the advantages of the present invention are: the drying control method of the present application is based on the principle of heat conservation. When the air volume is large, the temperature difference becomes smaller, and when the air volume is small, the temperature difference increases. Therefore, it is only necessary to adjust the air volume to judge whether the clothes are dried by the temperature difference changes under different air volumes; when the clothes are completely dried, no matter how the air volume changes, the temperature difference change is constant (will not fluctuate), therefore, the drying of the clothes is characterized by the difference between the inlet and outlet temperature difference caused by the air volume change and the change in the inlet and outlet temperature difference of the original air volume, and the drying can be accurately judged; the drying method of the present application is simple and convenient to implement, with low manufacturing cost, and no new detection instrument (such as weighing sensor) needs to be added. It can avoid misjudgment caused by external factors such as different mass, different ambient temperature, different thickness of clothes, different load types, different compressor operating conditions and fan operating conditions, and can achieve better drying effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a control flow chart of the drying control method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0031] This embodiment discloses a washer-dryer, the overall structure of which adopts existing technology. The washer-dryer includes an air inlet and an air outlet. The air inlet is provided with an air inlet temperature sensor for detecting the air inlet temperature, and the air outlet is provided with an air outlet temperature sensor for detecting the air outlet temperature.

[0032] In practical applications, conventional washer-dryers use the same dry temperature or temperature difference threshold regardless of the amount of laundry being dried, the ambient temperature, or changes in the compressor and fan operating conditions. This can easily lead to misjudgments and low dryness accuracy. As a result, small laundry items often get over-dried, while large laundry items remain under-dried. To address this issue, this embodiment implements the following drying control method to prevent environmental factors from interfering with dryness accuracy, improving dryness accuracy and achieving better drying results.

[0033] The drying control method of this embodiment includes the following steps: Figure 1 As shown:

[0034] Step 1: Start the program and initialize the settings.

[0035] Step 2: Adjust the air volume of the drying equipment to operate at the first air volume m1.

[0036] Step 3. Detect the current air inlet temperature and air outlet temperature, and calculate the current temperature difference between the air inlet and the air outlet as δt1; in order to reduce measurement errors and improve detection accuracy, the air inlet temperature and the air outlet temperature are respectively detected in real time by an air inlet temperature sensor set at the air inlet and an air outlet temperature sensor set at the air outlet. Considering the stability of equipment operation, the frequency of real-time detection of the air inlet temperature sensor and the air outlet temperature sensor is preferably once every 1 second.

[0037] Step 4: Determine whether the temperature difference δt1 in step 3 is less than or equal to the preset dry threshold temperature difference δt0. If yes, proceed to step 5; if not, return to step 3.

[0038] Step 5. Reduce the air volume of the drying equipment and operate it at the second air volume m2. In order to facilitate the detection of change data and take into account the drying efficiency, the relationship between the first air volume m1 and the second air volume m2 is: m2 = K × m1, where K is the air volume adjustment coefficient, and the value range of K is 0.5 to 0.9. If the air volume is reduced too little, that is, the value of K is too large, the temperature difference caused by the air volume change may be too small and difficult to identify. If the air volume is reduced too much, the drying time may be extended.

[0039] Step 6: Real-time detection: Detect the current air inlet temperature and air outlet temperature, and calculate the temperature difference between the current air inlet and air outlet as δt2; considering the stability of equipment operation, the frequency of real-time detection of the air inlet temperature sensor and the air outlet temperature sensor is preferably once every 1 second.

[0040] Step 7: Determine whether the temperature difference δt2 in step 6 is less than or equal to the preset dry threshold temperature difference δt0. If so, proceed to step 9; if not, proceed to step 8.

[0041] Step 8. Increase the air volume of the drying equipment again, operate at the first air volume m1, and last for t, then return to step 5; considering that increasing the air volume is a dynamic process, in order to ensure that the air volume can eventually be maintained at m1 and work stably, the duration t can range from 2 to 6 minutes. The setting of the duration t can avoid fluctuations and instability in the air volume adjustment process.

[0042] Step 9: Stop drying and the program ends.

[0043] The preset drying threshold temperature difference δt0 in this embodiment is usually the drying judgment threshold under ideal conditions. However, in the actual drying process, the amount of dried clothes, the ambient temperature, and changes in the working conditions of the compressor and fan will have a certain impact on the drying results. A single drying condition is prone to misjudgment, such as over-drying of small-mass clothes and under-drying of large-mass clothes. By changing the air volume to observe the temperature difference change, the drying status of the clothes can be indirectly reflected, which can improve the accuracy of drying judgment and enhance the drying effect.

[0044] In order to save time, the stopping time of the air volume increase process can be determined by judging the temperature difference, and the increase of the air volume can be stopped when the air volume increases to an appropriate size. Specifically, the above step eight can also be implemented by the following method:

[0045] Step 8-1, increase the air volume of the drying equipment;

[0046] Step 8-2: Detect the current air inlet temperature and air outlet temperature, and calculate the current temperature difference between the air inlet and the air outlet as δt3;

[0047] Step 8-3: Determine whether the temperature difference δt3 in step 8-2 is less than or equal to the dry threshold temperature difference δt0. If so, the air volume is considered to have reached a relatively high level, and further increases in air volume will not significantly change the temperature difference. Return to step 5. If not, continue increasing the air volume and repeat step 8-3. When the temperature difference is less than or equal to the preset threshold, the air volume increase is stopped and then reduced again. This alternating process of increasing and decreasing the air volume allows the clothes in the washing drum to be thoroughly dried.

[0048] This embodiment uses the heat transfer formula Q=cmΔT, where Q represents the heat transfer amount, c represents the constant-pressure specific heat of the wind, m represents the air volume, and ΔT represents the temperature drop of the wind. It can be seen that according to the principle of conservation of heat transfer, under the premise of the same heat transfer amount, m and ΔT are inversely proportional, that is, when the air volume is large, the temperature difference becomes smaller; when the air volume is small, the temperature difference increases.

[0049] This embodiment, based on the heat and mass transfer mechanisms of the clothes drying process, proposes a method for determining whether clothes are dry. This method addresses the issue of clothes of varying weight and material, under varying ambient temperatures, and is unaffected by the operating conditions of the compressor and fan. When the wind speed decreases, the temperature difference increases, thereby promoting drying. If the clothes are completely dry, heat is no longer exchanged between the air and the clothes, and the temperature difference remains constant. Therefore, the temperature difference caused by varying air volume can be used to detect whether the clothes are dry.

[0050] In the present specification and claims, directional terms such as "front," "back," "up," "down," "left," "right," "side," "top," and "bottom" are used to describe various exemplary structural parts and components of the present invention. However, these terms are used herein for convenience of description only and are based on the exemplary orientations shown in the accompanying drawings. Because the embodiments disclosed herein can be arranged in various orientations, these directional terms are intended for illustrative purposes only and should not be construed as limiting. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

Claims

1. A drying control method, characterized in that: The drying control method comprises the following steps: Step 1: Start the program and initialize the settings; Step 2: Adjust the air volume of the drying equipment to operate at the first air volume m1; Step 3: Detect the current air inlet temperature and air outlet temperature, and calculate the current temperature difference between the air inlet and the air outlet as δt1; Step 4: Determine whether the temperature difference δt1 in step 3 is less than or equal to the preset dry threshold temperature difference δt0. If yes, proceed to step 5; if not, return to step 3. Step 5: Reduce the air volume of the drying equipment and operate at the second air volume m2; Step 6: Detect the current air inlet temperature and air outlet temperature, and calculate the temperature difference between the current air inlet and air outlet as δt2; Step 7: Determine whether the temperature difference δt2 in step 6 is less than or equal to the preset dry threshold temperature difference δt0. If so, proceed to step 9; if not, proceed to step 8. Step 8: Increase the air volume of the drying equipment to operate at the first air volume m1 for a duration of t, and then return to step 5; Step 9: Stop drying and the program ends.

2. The drying control method according to claim 1, characterized in that: The relationship between the first air volume m1 and the second air volume m2 is: m2=K×m1, where K is an air volume adjustment coefficient, and the value range of K is 0.5 to 0.

9.

3. The drying control method according to claim 1, wherein: The duration t in step eight ranges from 2 to 6 minutes.

4. The drying control method according to claim 1, characterized in that: The step eight can also be achieved by the following method: Step 8-1, increase the air volume of the drying equipment; Step 8-2: Detect the current air inlet temperature and air outlet temperature, and calculate the current temperature difference between the air inlet and the air outlet as δt3; Step 8-3: Determine whether the temperature difference δt3 in step 8-2 reaches the dry threshold temperature difference δt0. If so, return to step 5; if not, continue to increase the air volume and loop through step 8-3.

5. The drying control method according to claim 1, characterized in that: The air inlet temperature and the air outlet temperature in step three are respectively detected in real time by an air inlet temperature sensor arranged at the air inlet and an air outlet temperature sensor arranged at the air outlet.

6. The drying control method according to claim 5, characterized in that: The frequency of real-time detection of the inlet air temperature sensor and the outlet air temperature sensor is once every 1 to 10 seconds.

7. The drying control method according to claim 1, characterized in that: The air inlet temperature and the air outlet temperature in step six are respectively detected in real time by an air inlet temperature sensor provided at the air inlet and an air outlet temperature sensor provided at the air outlet.

8. The drying control method according to claim 7, characterized in that: The frequency of real-time detection of the inlet air temperature sensor and the outlet air temperature sensor is once every 1 to 10 seconds.

9. A washer-dryer comprising an air inlet and an air outlet, characterized in that: The washer-dryer adopts the drying control method described in any one of claims 1 to 8 to implement the drying process.

10. The drying control method according to claim 9, characterized in that: The air inlet is provided with an air inlet temperature sensor for detecting the air inlet temperature, and the air outlet is provided with an air outlet temperature sensor for detecting the air outlet temperature.

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