Bathroom heating, ventilation, and drying system

Abstract

The objective is to provide a bathroom heating, ventilation, and drying system that can dry clothes in the bathroom more efficiently. [Solution] In drying mode, the control device 30 keeps the heater 25 off, ventilates using the blower 21, and calculates an estimated absolute humidity outside the bathroom 60 by estimating the convergence prediction value of the absolute humidity inside the bathroom 60 from the exponential decay of the absolute humidity inside the bathroom 60. After this, the control device 30 turns on the heater 25 and uses the estimated absolute humidity outside the bathroom 60 to determine if the clothes are dry.

Description

Technical Field

[0001] The present disclosure relates to a bathroom heating, ventilation and drying machine.

Background Art

[0002] In a conventional bathroom heating and drying machine, when drying clothes in a bathroom, if the absolute humidity becomes less than or equal to the drying determination value, or if the detected humidity does not change for a set time, the drying operation is stopped (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional bathroom heating and drying machine as described above, the drying determination value of the absolute humidity is initially set to an absolute humidity at which clothes can dry even under difficult drying conditions. Therefore, even if the clothes are sufficiently dried, the operation may not stop, and the clothes may not be dried efficiently.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to obtain a bathroom heating, ventilation and drying machine that can dry clothes in a bathroom more efficiently.

Means for Solving the Problems

[0006] The bathroom heating, ventilation and drying machine according to the present disclosure includes a dryer body having a blower and a heater, and a control device that controls the dryer body by a plurality of operation modes including a drying operation mode for drying clothes in the bathroom. In the drying operation mode, the control device performs ventilation by the blower while keeping the heater off, estimates a convergence prediction value of the absolute humidity in the bathroom from the exponential decay of the absolute humidity in the bathroom, calculates an estimated value of the absolute humidity outside the bathroom, then turns on the heater, and uses the estimated value to determine the drying of the clothes. Further, the bathroom heating, ventilation and drying machine according to the present disclosure includes a dryer body having a blower and a heater, and a control device that controls the dryer body by a plurality of operation modes including a drying operation mode for drying clothes in the bathroom. One or more conditions for determining the drying of the clothes are set in the control device. The one or more conditions include the condition that after the slope of the absolute humidity in the bathroom becomes a negative value, the absolute humidity in the bathroom passes through an inflection point, or the slope of the absolute humidity in the bathroom passes through a minimum value. In the drying determination, the control device proceeds to the drying end process after clearing all of the one or more conditions. Further, the bathroom heating, ventilation and drying machine according to the present disclosure includes a dryer body having a blower and a heater, and a control device that controls the dryer body by a plurality of operation modes including a drying operation mode for drying clothes in the bathroom. One or more conditions for determining the drying of the clothes are set in the control device. The one or more conditions include at least one of the conditions that a physical quantity obtained by dividing the difference between the current absolute humidity in the bathroom and the estimated value of the absolute humidity outside the bathroom by the difference between the current saturated absolute humidity calculated from the temperature in the bathroom and the initial value of the saturated absolute humidity is not more than an error threshold value, and that the absolute value of the slope of the physical quantity is not more than a slope threshold value. In the drying determination, the control device proceeds to the drying end process after clearing all of the one or more conditions. Furthermore, the bathroom heating, ventilation, and drying machine according to this disclosure includes a dryer body having a blower and a heater, and a control device that controls the dryer body with multiple operating modes, including a drying operation mode for drying clothes in the bathroom. The control device has one or more conditions set for determining whether the clothes are dry. When the current saturated absolute humidity calculated from the temperature in the bathroom is F, the initial value of the saturated absolute humidity is F0, the current relative humidity in the bathroom is R, and the estimated absolute humidity outside the bathroom is X0, and R0 = X0 / F0, one or more of the conditions include the condition that the absolute value of the slope of the physical quantity ((FR-F0R0)(F0R-FR0)) / ((R-R0)(F-F0)) is less than or equal to a determination threshold. In determining whether the clothes are dry, the control device proceeds to the drying completion process after clearing all one or more conditions. Furthermore, the bathroom heating, ventilation, and drying machine according to this disclosure comprises a dryer body having a blower and a heater, and a control device that controls the dryer body by multiple operating modes, including a drying operation mode for drying clothes in the bathroom. The control device has one or more conditions set for determining whether the clothes are dry, and one or more conditions include a first condition in which the absolute humidity in the bathroom passes an inflection point or the slope of the absolute humidity in the bathroom passes a minimum value after the slope of the absolute humidity in the bathroom becomes a negative value, and a second condition in which the difference between the current absolute humidity in the bathroom and the estimated absolute humidity outside the bathroom is divided by the difference between the current saturated absolute humidity calculated from the temperature in the bathroom and the initial value of the saturated absolute humidity. The system includes at least one of the following conditions: a second condition that the physical quantity is below an error threshold, and a third condition that the absolute value of the slope of the physical quantity is below a slope threshold; and a fourth condition that, when F is the current saturated absolute humidity calculated from the temperature inside the bathroom, F0 is the initial value of the saturated absolute humidity, R is the current relative humidity inside the bathroom, X0 is the estimated absolute humidity outside the bathroom, and R0 = X0 / F0, the absolute value of the slope of the physical quantity ((FR-F0R0)(F0R-FR0)) / ((R-R0)(F-F0)) is below a judgment threshold. The control device proceeds to the drying completion process only after all one or more of these conditions are met in the drying determination. Furthermore, the bathroom heating, ventilation, and drying machine according to this disclosure comprises a dryer body having a blower and a heater, and a control device that controls the dryer body with multiple operating modes, including a drying operation mode for drying clothes in the bathroom. The control device has one or more conditions set for determining whether the clothes are dry. For each of the one or more conditions, the control device accumulates the heater current value while the condition is met, resets the accumulated value of the heater current when the condition is no longer met, and proceeds to the drying completion process when the accumulated value for all one or more conditions exceeds a heat threshold. [Effects of the Invention]

[0007] According to the bathroom heating, ventilation, and drying machine of this disclosure, clothes in the bathroom can be dried more efficiently. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view of a bathroom heating, ventilation, and drying machine according to Embodiment 1. [Figure 2] Figure 1 is a flowchart showing the processing performed by the control unit during the drying operation of the bathroom heating, ventilation, and drying unit. [Figure 3] Figure 2 is a flowchart detailing the process in step S100. [Figure 4] Figure 2 is a flowchart detailing the process in step S300. [Figure 5] This graph shows an example of how absolute humidity changes over time in determining dryness. [Figure 6] This graph shows an example of the time change in the area difference of absolute humidity used in determining dryness. [Figure 7] This graph shows an example of how the estimated humidity error in dryness assessment changes over time. [Figure 8] This graph shows the relationship between the time-dependent change in absolute humidity inside a bathroom and the comparison conditions. [Figure 9] This graph shows the relationship between the time-dependent change in absolute humidity in a bathroom and equivalent conditions. [Figure 10]This graph shows the relationship between the time-dependent change in absolute humidity inside the bathroom and the second condition. [Figure 11] This graph shows an example of how the absolute value of the humidity error estimate changes over time in a dryness determination. [Figure 12] This graph shows an example of the time evolution of the absolute value of the slope |dX'| of the physical quantity dX in the drying determination. [Figure 13] This graph shows the original data before smoothing. [Figure 14] This graph shows the moving average data after smoothing. [Figure 15] This graph shows the current area in moving average data. [Figure 16] This graph shows the area difference corresponding to Figure 15. [Figure 17] This is a configuration diagram showing a first example of a processing circuit that realizes each function of the control device of Embodiment 1. [Figure 18] This is a configuration diagram showing a second example of a processing circuit that realizes each function of the control device of Embodiment 1. [Modes for carrying out the invention]

[0009] The embodiments will be described below with reference to the drawings. Embodiment 1. Figure 1 is a schematic cross-sectional view of a bathroom heating, ventilation, and drying machine according to Embodiment 1. In the figure, the bathroom heating, ventilation, and drying machine 50 is installed on the ceiling 61 of the bathroom 60, facing into the bathroom 60.

[0010] The bathroom heating, ventilation, and drying unit 50 can perform ventilation, heating, and drying operations. Heating operation is a method of heating the air taken in from the bathroom 60 and returning it to the bathroom 60. Ventilation operation is a method of exhausting the air taken in from the bathroom 60 to the outside of the bathroom 60. Drying operation is a method of exhausting the air taken in from the bathroom 60 to the outside of the bathroom 60, while simultaneously sending warm or cool air into the bathroom 60 to dry the inside of the bathroom 60.

[0011] The bathroom heating, ventilation, and drying machine 50 comprises a drying machine body 10 and a control device 30. The drying machine body 10 includes a housing 11, a blower 21, a damper 24, a heater 25, and a temperature and humidity sensor 26.

[0012] The lower part of the housing 11 is provided with an intake port 11a and an outlet port 11b. Air from inside the bathroom 60 is drawn into the housing 11 through the intake port 11a. A filter 12 is provided at the intake port 11a.

[0013] The housing 11 is provided with an exhaust duct connection section 11c. An exhaust duct (not shown) is connected to the exhaust duct connection section 11c. A decorative panel 14 is provided at the bottom of the housing 11.

[0014] The blower 21 is located directly above the intake port 11a inside the housing 11. The blower 21 also has a blower motor 22 and a fan 23. The blower motor 22 rotates the fan 23. As a result, the blower 21 draws air from the bathroom 60 into the housing 11 and sends the drawn-in air either inside the bathroom 60 or outside.

[0015] The damper 24 is located inside the housing 11. The damper 24 is rotatable between a circulation position and an exhaust position around a horizontal shaft 24a by a flow path switching motor (not shown). A stepping motor is used as the flow path switching motor. The circulation position is the position that blocks the flow path to the outside. The exhaust position is the position that blocks the flow path back into the bathroom 60, and is the position rotated counterclockwise from the circulation position as shown in Figure 1.

[0016] The damper 24 rotates between a circulation position and an exhaust position, thereby switching the airflow path within the housing 11 between a circulation path and an exhaust path. The circulation path is the path that returns the air taken into the housing 11 back into the bathroom 60. The exhaust path is the path that discharges the air taken into the housing 11 to the outside.

[0017] When the damper 24 is in the circulation position, the air inside the housing 11 is returned to the bathroom 60 through the air outlet 11b. When the damper 24 is in the exhaust position, the air inside the housing 11 is discharged to the outside through the exhaust duct connection 11c and the exhaust duct.

[0018] The heater 25 is located directly above the air outlet 11b inside the housing 11. During heating operation, the heater 25 heats the air that is returned from inside the housing 11 into the bathroom 60.

[0019] The temperature and humidity sensor 26 is located on the edge of the intake port 11a. This allows the temperature and humidity sensor 26 to detect the temperature and relative humidity of the air drawn into the housing 11. In other words, the temperature and humidity sensor 26 detects the temperature and relative humidity of the air inside the bathroom 60.

[0020] The control device 30 is located on the upper part of the housing 11. The control device 30 also controls the dryer body 10 using multiple operating modes.

[0021] The multiple operating modes include a ventilation mode, a heating mode, and a drying mode. The ventilation mode is the mode in which ventilation is performed. The heating mode is the mode in which heating is performed. The drying mode is the mode in which drying is performed.

[0022] Figure 2 is a flowchart showing the processing performed by the control device 30 during the drying operation of the bathroom heating, ventilation, and drying unit 50 shown in Figure 1. During the drying operation, warm air is sent into the bathroom 60. This dries the clothes inside the bathroom 60.

[0023] During drying operation, the damper 24 is set to a drying position between the circulation position and the exhaust position. The blower motor 22 is also operated in the "high notch" position.

[0024] When the drying operation starts, in step S100, the control device 30 estimates the absolute humidity outside the bathroom 60 with the heater 25 turned off. At this time, the control device 30 calculates the absolute humidity inside the bathroom 60 from the relative humidity inside the bathroom 60 detected by the temperature and humidity sensor 26. The control device 30 also estimates the absolute humidity outside the bathroom 60 from the time change in the absolute humidity inside the bathroom 60. Outside the bathroom 60 is, for example, the dressing room adjacent to the bathroom 60.

[0025] Next, in step S200, the control device 30 turns on the heater 25. Then, in step S300, the control device 30 determines whether the four determination conditions described later are simultaneously met. The determination of whether the four determination conditions are simultaneously met is whether the clothes are dry.

[0026] If all four conditions are met simultaneously, the control device 30 proceeds to the finishing operation as the drying completion process in step S400. In other words, the drying completion process in Embodiment 1 is the process of performing the finishing operation.

[0027] Subsequently, in step S500, the control device 30 determines whether the set time has elapsed. The set time is the time set by the user. The control device 30 continues the drying operation as a finishing operation until the set time has elapsed.

[0028] When the set time has elapsed, the control device 30 stops the operation of the dryer unit 10 in step S600 and terminates the process. In other words, in the finishing operation, the drying operation mode continues for a time set by the user before the operation of the dryer unit 10 is stopped.

[0029] <Estimation of absolute humidity outside the bathroom> Next, we will explain the details of the process in step S100 in Figure 2. First, we will explain the differential equation for the absolute humidity in bathroom 60 and the method for deriving its solution. We will assume that there are only the following two absolute humidity balances in bathroom 60. (i) Evaporation and absorption of moisture from clothing, floors, walls, etc. (ii) Exhaustion of moisture from inside the bathroom 60 through ventilation and intake of dry air from outside the bathroom 60.

[0030] Here, V[m 3 ] is the volume of the bathroom, U[m 3 / s] is the ventilation air volume, v(t)[g / s] is the evaporation rate, x(t)[g / m 3 ] The absolute humidity inside the bathroom 60, x out [g / m 3 If we take ] as the absolute humidity outside bathroom 60, then the following differential equation holds true based on the absolute humidity balance inside bathroom 60.

[0031]

number

[0032] This differential equation can be solved using the method of variation of parameters, as shown below.

[0033]

number

[0034] Substituting this, we obtain the following equation.

[0035]

number

[0036] Using the fact that x(0)=D(0)=x0, D(t) becomes as follows:

[0037]

number

[0038] The absolute humidity inside the bathroom is,

[0039]

number

[0040] By substituting D(t), it can be expressed in the following form.

[0041]

Number

[0042] Next, a method for estimating the absolute humidity outside the bathroom 60 will be described. The evaporation rate when the heater 25 is turned off and the drying operation is in progress is assumed to be a constant value

[0043]

Number

[0044] Let's assume it becomes.

[0045] If the time at the start of operation at each notch is set as t0 and the absolute humidity in the bathroom 60 at that time is set as x0, x(t) is expressed in the following form.

[0046]

Number

[0047] Here, consider measuring the absolute humidity x(t) in the bathroom 60 at the sampling time Δt. Substituting with t = t i = t0 + iΔt, then x(t i ) = x i is expressed in the following form.

[0048]

Number

[0049] Taking the sum from x0 to x p-1 up to,

[0050]

Number

[0051] If we define it as follows, we obtain the following equation.

[0052]

number

[0053] Rearranging this equation, we get the following:

[0054]

number

[0055] Here, we prepare two equations for p in the above formula: p=m>0 and p=n>m. In this case, if we assume that m is approximately equal to n / 2, we can expect the estimation accuracy to improve.

[0056] Since the left-hand sides of the two equations are common, they cancel each other out.

[0057]

number

[0058] This can be estimated using the following formula.

[0059]

number

[0060] This estimation is performed under the assumption that the ventilation airflow rate and bathroom volume are known. The control device 30 calculates the estimated value by estimating two or more convergent predicted values ​​for two or more ventilation airflow rates. By performing estimation with multiple notches, the absolute humidity outside the bathroom 60 x out It is possible to estimate this.

[0061] However, operating with multiple notches each time an estimation is performed could affect product lifespan and other factors. Therefore,

[0062]

number

[0063] Assuming this is the case, with only one notch, x is as follows: out We estimate this.

[0064]

number

[0065] The control device 30 has preset measurement time, variation confirmation time, variation threshold, and upper limit time.

[0066] The control device 30 measures the average value of the absolute humidity inside the bathroom 60 at each measurement time. The control device 30 also checks at each fluctuation check time whether the amount of fluctuation in the average value of the absolute humidity has fallen below the fluctuation threshold.

[0067] When the fluctuation amount of the average value of absolute humidity falls below the fluctuation threshold, the control device 30 estimates the absolute humidity outside the bathroom 60 using the average value up to that point. Furthermore, when the elapsed time since the start of absolute humidity measurement reaches the upper limit, the control device 30 estimates the absolute humidity outside the bathroom 60 using the average value up to that point, regardless of the fluctuation amount of the average value.

[0068] Figure 3 is a flowchart detailing the process in step S100 of Figure 2. In this example, the measurement time is set to 1 minute. The variation confirmation time is set to 2 minutes. The upper limit time is set to 10 minutes.

[0069] When the drying operation starts, in step S101, the control device 30 sets the damper 24 to the drying position and operates the blower motor 22 at the high setting. The heater 25 remains off.

[0070] In this state, the control device 30 waits for a preset waiting time in step S102. The waiting time is preset to, for example, 1 minute. The reason for setting a waiting time is that the measured values ​​are not stable immediately after the start of operation.

[0071] Next, in step S103, the control device 30 calculates the count value t of the elapsed time since the start of absolute humidity measurement. est , the count value Δt of the time for checking the change est The measurement count k and the number of measurements are reset to their initial values ​​of 0. Additionally, the storage location Lx for the measured values ​​is reset.

[0072] Subsequently, in step S104, the control device 30 starts acquiring measurement data from the temperature and humidity sensor 26. Then, in step S105, the control device 30 acquires the count value Δt est However, it waits until the measurement time interval of 1 minute has been reached.

[0073] Count value Δt est When this reaches 1 minute, the control device 30, in step S106, calculates the average absolute humidity for the most recent 1 minute, and the latest measured value x k It will be stored in storage location Lx.

[0074] Next, in step S107, the control device 30 calculates the count value Δt est Until another minute is added, i.e., the count value Δt est Wait until the 2-minute fluctuation confirmation time has been reached.

[0075] Count value Δt est When this reaches 2 minutes, the control device 30, in step S108, calculates the average absolute humidity for the most recent 1 minute, and the latest measured value x k It is stored in storage location Lx. The control device 30 also stores the count value Δt est Reset it.

[0076] Subsequently, in step S109, the control device 30 controls the count value t estIt determines whether the time limit of 10 minutes has been reached.

[0077] If the upper limit time has not been reached, in step S110, the control device 30 determines that the amount of variation in the average value of absolute humidity is the variation threshold ε. est Check if the following conditions are met: The amount of change is the variation threshold ε. est If the following conditions are not met, the control device 30 returns to the process of step S105.

[0078] In the process of step S109, the count value t est If the upper limit time is reached, and in the processing of step S110 the amount of variation is the variation threshold ε est If the following conditions are met, the control device 30 estimates the absolute humidity outside the bathroom 60 in step S111.

[0079] At this time, the control device 30 calculates an estimated absolute humidity outside the bathroom 60 by estimating the convergence prediction value of the absolute humidity inside the bathroom 60 from the exponential decay of the absolute humidity inside the bathroom 60.

[0080] Specifically, the control device 30 sets the estimated absolute humidity X0 outside the bathroom 60 as the minimum absolute humidity X during the measurement period. min And the convergence prediction value X calculated from the theoretical formula. est The smaller of the two values ​​will be used.

[0081] That is, X0 = MIN(X min , X est ), X min =MIN(Lx). And the convergence prediction value X est It can be calculated using the following formula, where n=k and m=2 / k.

[0082]

number

[0083] Furthermore, the control device 30 calculates the saturated absolute humidity from the temperature inside the bathroom 60 when calculating the estimated value X0, and records it as the initial value F0 of the saturated absolute humidity.

[0084] After determining the estimated value X0, the control device 30 proceeds to the process of step S200 in Figure 2.

[0085] <Dry judgment> Next, the details of the process in step S300 in Figure 2 will be described. Figure 4 is a flowchart detailing the process in step S300 in Figure 2. One or more conditions are set in the control device 30. In the control device 30 of Embodiment 1, a first condition, a second condition, a second condition, and a fourth condition are set.

[0086] Furthermore, the control device 30 is configured with a first heat threshold σ1, a second heat threshold σ2, a third heat threshold σ3, and a fourth heat threshold σ4 as current area thresholds. The current area is the area of ​​the waveform that shows the time change of the current value of the heater 25, that is, the time integral of the current value.

[0087] The control device 30 accumulates the current value of the heater 25 for each of the four conditions while the condition is met, and resets the accumulated value of the heater 25's current value to 0 when the condition is no longer met. Then, for all conditions, when the accumulated value exceeds the heat threshold, the control device 30 proceeds to the drying completion process.

[0088] When the drying determination is started, the control device 30 determines in step S301 whether the first condition has been met. The control device 30 then determines in step S302 whether the second condition has been met. The control device 30 then determines in step S303 whether the third condition has been met. The control device 30 then determines in step S304 whether the fourth condition has been met.

[0089] Details of the first, second, third, and fourth conditions will be described later. The control device 30 executes the processes in steps S301 to S304, for example, every minute.

[0090] If the first condition is met, the control device 30 counts the current area Z in step S311. Then, in step S312, the control device 30 determines whether the current area Z is greater than or equal to the first heat threshold σ1.

[0091] If the current area Z is greater than or equal to the first heat threshold σ1, the control device 30 sets the first determination result J1 to "1" in step S313.

[0092] If the first condition is not met, and the current area Z is not equal to or greater than the first heat threshold σ1, the control device 30 resets the current area Z in step S314. Then, in step S315, the control device 30 sets the first determination result J1 to "0".

[0093] If the second condition is met, the control device 30 counts the current area Z in step S321. Then, in step S322, the control device 30 determines whether the current area Z is greater than or equal to the second heat threshold σ2.

[0094] If the current area Z is greater than or equal to the second heat threshold σ2, the control device 30 sets the second determination result J2 to "1" in step S323.

[0095] If the second condition is not met, and the current area Z is not equal to or greater than the second heat threshold σ2, the control device 30 resets the current area Z in step S324. Then, in step S325, the control device 30 sets the second determination result J2 to "0".

[0096] If the third condition is met, the control device 30 counts the current area Z in step S331. Then, in step S332, the control device 30 determines whether the current area Z is greater than or equal to the third heat threshold σ3.

[0097] If the current area Z is greater than or equal to the third heat threshold σ3, the control device 30 sets the third determination result J3 to "1" in step S333.

[0098] If the third condition is not met, and the current area Z is not equal to or greater than the third heat threshold σ3, the control device 30 resets the current area Z in step S334. Then, in step S335, the control device 30 sets the third determination result J3 to "0".

[0099] If the fourth condition is met, the control device 30 counts the current area Z in step S341. Then, in step S342, the control device 30 determines whether the current area Z is greater than or equal to the fourth heat threshold σ4.

[0100] If the current area Z is greater than or equal to the fourth heat threshold σ4, the control device 30 sets the fourth determination result J4 to "1" in step S343.

[0101] If the fourth condition is not met, and the current area Z is not equal to or greater than the fourth heat threshold σ4, the control device 30 resets the current area Z in step S344. Then, in step S345, the control device 30 sets the fourth determination result J4 to "0".

[0102] Subsequently, in step S305, the control device 30 determines whether all of the first determination result J1, the second determination result J2, the third determination result J3, and the fourth determination result J4 are "1", that is, whether all four determination conditions are met simultaneously.

[0103] If all four determination conditions are met simultaneously, the control device 30 proceeds to the process of step S400 in Figure 2.

[0104] If one or more of the four determination conditions are not met, the control device 30 returns to the processing of steps S301 to S304.

[0105] In addition, to reduce the risk of misjudgment during the drying process, the raw data is smoothed using a moving average before determining whether each condition is met. Details of the smoothing process will be described later.

[0106] Furthermore, in determining dryness, the area difference is used instead of the slope. Also, when the heater 25 is off, the area difference becomes small even if the clothes are not dry, which carries a risk of misjudgment, so the area difference is corrected by the current area. Details of the area difference calculation will be described later.

[0107] <Condition 1> The first condition is that after the slope of the absolute humidity in the bathroom 60 becomes a negative value, the absolute humidity in the bathroom 60 passes through an inflection point, or the slope of the absolute humidity in the bathroom 60 passes through its minimum value.

[0108] Figure 5 is a graph showing an example of the time change in absolute humidity in the dryness determination. Figure 6 is a graph showing an example of the time change in the area difference of absolute humidity in the dryness determination. As shown in Figures 5 and 6, the absolute humidity in the bathroom 60 passing through an inflection point is approximately equivalent to the slope of the absolute humidity in the bathroom 60 passing through its minimum value.

[0109] Near the inflection point of absolute humidity, the evaporation of moisture from clothing slows down to some extent, and the absolute humidity inside bathroom 60 converges to the absolute humidity outside bathroom 60. In order to ensure that the minimum value of the slope of absolute humidity is passed, the condition is set that it becomes less than or equal to α1 times the absolute value of the current slope of absolute humidity, where 0 < α1 < 1.

[0110] <Condition 2> The second condition is the physical quantity e RThe condition is that (X-X0) / (F-F0) is less than or equal to the error threshold α2. X-X0 is the difference between the current absolute humidity X inside bathroom 60 and the estimated absolute humidity X0 outside bathroom 60. F-F0 is the difference between the current saturated absolute humidity F inside bathroom 60 and the initial saturated absolute humidity F0 inside bathroom 60. The saturated absolute humidity F and the initial value F0 are calculated from the temperature inside bathroom 60.

[0111] The control device 30 calculates the physical quantity e by dividing the difference between absolute humidity X and the estimated value X0 by the difference between the saturated absolute humidity F in the bathroom 60 and the initial value F0 of the saturated absolute humidity. R Calculate and record the physical quantity e. R It is determined whether the result falls below the error threshold α2.

[0112] Figure 7 is a graph showing an example of the time change in the estimated humidity error value for drying determination. If the absolute humidity outside the bathroom 60 is nearly constant during clothes drying, and the estimated absolute humidity X0 outside the bathroom 60 at the start of operation is accurate, then the absolute humidity X inside the bathroom 60 when the clothes are dry will be approximately the same as the estimated value X0 outside the bathroom 60.

[0113] Focusing on this property, it is conceivable to perform a dryness determination under the condition X-X0≦a (where a is a constant). Hereafter, this condition will be referred to as the comparison condition. However, the comparison condition is not suitable when there is a significant error in the humidity sensor's measurement.

[0114] In fact, humidity sensors have been observed where the relative humidity measurement is offset by as much as 10%RH, and in the case of significant errors, the time at which the comparison conditions are met varies greatly. Therefore, in Embodiment 1, the above second condition, which is robust to the offset error of the temperature and humidity sensor 26, is adopted.

[0115] The second condition can be rewritten as the equivalent condition X-X0 ≤ α2(F-F0). We will compare the robustness of the humidity sensor against errors with respect to this equivalent condition and the comparison condition.

[0116] Figure 8 is a graph showing the relationship between the time change in absolute humidity in bathroom 60 and the comparison conditions. Figure 9 is a graph showing the relationship between the time change in absolute humidity in bathroom 60 and the equivalent conditions. Figure 10 is a graph showing the relationship between the time change in absolute humidity in bathroom 60 and the second condition.

[0117] Comparing these graphs, it can be seen that the difference in the time it takes for the conditions to be met is smaller for the equivalent condition and the second condition than for the comparison condition. Also, assuming there is an error ΔR in the humidity sensor measurement, the absolute humidity fluctuation ΔX when the comparison condition is met can be expressed by the following equation.

[0118] X1-X0=a

[0119] X2 + F2ΔR - X0 - F0ΔR = a

[0120] Therefore, ΔX = X2 - X1 = -(F2 - F0)ΔR

[0121] Furthermore, the absolute humidity fluctuation ΔX when the equivalence conditions are met can be expressed by the following equation.

[0122] X1-X0=α2(F-F0)

[0123] X3 + F3ΔR - X0 - F0ΔR = α2(F3 - F0)

[0124] ∴ΔX=X3-X1=-(F3-F0)ΔR+α2(F3-F1)

[0125] From the above equation, we can see that the equivalence condition includes a term α2(F3-F1), which relaxes the variation ΔX.

[0126] Therefore, it can be said that the second condition is more robust to the error of the humidity sensor than the comparison condition.

[0127] Here, e RLet's consider the physical meaning of this value. Let's consider the case where the humidity sensor has an offset error of ΔR, and the true value of the initial absolute humidity is equal to the true value of the current absolute humidity. The observed value of the initial absolute humidity X0 and the observed value of the current absolute humidity X are both affected by the humidity error, and if we subtract that and set up the relationship, it becomes as follows.

[0128] X0 - F0ΔR = X - FΔR

[0129] Rearranging this equation for ΔR, we get the following:

[0130] ΔR=(X-X0) / (F-F0)=e R

[0131] From the results, e R This value represents the error of the humidity sensor, assuming that the entire difference between the initial observed absolute humidity and the current observed absolute humidity is due to the error of the humidity sensor. Naturally, the true value of absolute humidity fluctuates during the drying process of clothes, so e R This value may not always be close to the actual error value of the humidity sensor.

[0132] However, except in exceptional cases, the absolute humidity when clothing is dry and no more moisture evaporates is approximately equal to the initial absolute humidity, so e R Ultimately, this will approach the error value of the actual humidity sensor.

[0133] <Third condition> The third condition is the physical quantity e R The condition is that the absolute value of the slope is less than or equal to the slope threshold α3. Figure 11 is a graph showing an example of the time change in the absolute value of the humidity error estimate in the dryness determination.

[0134] The slope threshold α3 is set so that the judgment becomes stricter for short and long periods of time. In other words, the slope threshold α3 is set so that the judgment becomes stricter when there is a small amount of clothing and when some of the clothing dries slowly.

[0135] In fact, e R The derivative of =(X-X0) / (F-F0) e R When we calculate ', we get the following:

[0136] e R '=((F'R+FR')(F-F0)-(FR-F0R0)F') / (F-F0) 2 =(F0F'(R0-R)+FR'(F-F0)) / (F-F0) 2

[0137] Here, if an offset error of ΔR occurs in the humidity sensor, e R Let's check how much it shifts. Substituting R0+ΔR for R0 in the above equation and R+ΔR for R, we get the following.

[0138] e R '=(F0F'(R0+ΔR-R+ΔR)+F(R+ΔR)'(F-F0)) / (F-F0) 2 =(F0F'(R0-R)+FR'(F-F0)) / (F-F0) 2

[0139] As can be seen from this formula, e differs between the case where there is no error in the humidity sensor and the case where an offset error occurs. R ' becomes equal. Therefore, the third condition can also be said to be a condition that provides high robustness against errors in the humidity sensor. <Condition 4> The fourth condition is the physical quantity d shown in the following equation. X The condition is that the absolute value of the slope is less than or equal to the judgment threshold α4.

[0140] d X =((FR-F0R0)(F0R-FR0)) / ((R-R0)(F-F0))

[0141] F is the current saturated absolute humidity calculated from the temperature inside bathroom 60. F0 is the initial value of the saturated absolute humidity. R is the current relative humidity inside bathroom 60. R0 is the value obtained by dividing the estimated absolute humidity X0 outside bathroom 60 by the initial value F0. That is, R0 = X0 / F0.

[0142] Figure 12 shows the physical quantity d in the drying determination. X The absolute value of the slope |d X This graph shows an example of how the value of '|' changes over time.

[0143] The judgment threshold α4 is set so that the judgment becomes stricter for short and long periods of time. In other words, the judgment threshold α4 is set so that the judgment becomes stricter when there is a small amount of clothing and when some of the clothing dries slowly.

[0144] d X d is a physical quantity with the same dimensions as absolute humidity, and it asymptotically approaches a constant value as the clothes dry. Therefore, the derivative value d X ' will eventually asymptotically approach 0. Also, the derivative value d X ' is easy to use for determining dryness because the amount of change is large. Differential value d X When we actually calculate ', we get the following:

[0145]

number

[0146] <Smoothing process> In this process, to reduce the risk of misjudgment during the drying process, the data is smoothed. Figure 13 is a graph showing the original data before smoothing. Figure 14 is a graph showing the moving average data after smoothing.

[0147] The data detected by the temperature and humidity sensor 26 should preferably be formatted to reduce the risk of misinterpretation. In Embodiment 1, the original data is smoothed by the following procedure.

[0148] (i) Record temperature, relative humidity, and absolute humidity as raw data every 5 seconds. (ii) Use the original data to calculate the average value over one minute. (iii) Take a moving average using 30 average values.

[0149] <Calculation of area difference> In the dryness determination, area difference is used instead of slope. Furthermore, to reduce the risk of misjudgment, the area difference is corrected by the current area. Figure 15 is a graph showing the current area in the moving average data. Figure 16 is a graph showing the area difference corresponding to Figure 15.

[0150] The area difference is calculated using the following procedure.

[0151] (i) Using 30 moving average data points, calculate (sum of the last 15 moving average data points) - (sum of the first 15 moving average data points). That is, calculate the area difference for each 15-minute period. (ii) κ0 / (MAX(S I ,κ min Multiply the area difference calculated in (i) by (MAX(measured current area, minimum current area)) = current area reference value / (MAX(measured current area, minimum current area)). However, κ0 and κ min These are all constants.

[0152] <Finishing operation> In the finishing cycle, drying continues for a set time after the drying judgment is completed. The user can change the set time using the control switch, etc. Furthermore, by incorporating the finishing cycle into the automatic drying flow, the degree of drying of clothes can be adjusted according to the user's preference. The remaining time until automatic stop can also be displayed on a timer.

[0153] In this type of bathroom heating, ventilation, and drying unit 50, the heater 25 is kept off while ventilation is performed by the blower 21. By estimating the convergence prediction value of the absolute humidity inside the bathroom 60 from the exponential decay of the absolute humidity inside the bathroom 60, an estimated value of the absolute humidity outside the bathroom 60 is calculated. Then, the drying status of the clothes is determined using the calculated estimated value.

[0154] Therefore, the operation of the dryer unit 10 is prevented from stopping before the clothes are dry, and the operation of the dryer unit 10 is prevented from continuing after the clothes are sufficiently dry. As a result, the clothes in the bathroom 60 can be dried more efficiently.

[0155] Furthermore, the control device 30 calculates an estimated absolute humidity outside the bathroom 60 by estimating two or more convergence prediction values ​​for two or more ventilation airflow rates. This reduces the influence of moisture evaporation from clothing, walls, and the water in the bathtub.

[0156] Furthermore, the control device 30 proceeds to the drying completion process only after all one or more conditions have been met. This allows for more reliable and efficient drying of the clothes in the bathroom 60.

[0157] Furthermore, the control device 30 is configured with the above-mentioned first condition. As a result, the clothes in the bathroom 60 can be dried more efficiently.

[0158] Furthermore, the control device 30 is configured with the above-mentioned second and third conditions. This makes it more robust against offset errors due to the aging of the temperature and humidity sensor 26. Consequently, clothes in the bathroom 60 can be dried more efficiently.

[0159] Furthermore, the control device 30 is configured with the above-mentioned fourth condition. This allows the clothes in the bathroom 60 to be dried more efficiently.

[0160] Furthermore, for each of the one or more conditions, the control device 30 accumulates the current value of the heater 25 while the condition is met, and resets the accumulated value of the heater 25's current value when the condition is no longer met. Then, when the accumulated value for all one or more conditions exceeds the heat threshold, the control device 30 proceeds to the drying completion process.

[0161] Therefore, it is possible to suppress the system from mistakenly transitioning to the termination process when the number of powered heaters 25 is low, thereby suppressing misjudgments in the drying judgment and allowing clothes in the bathroom 60 to be dried more efficiently.

[0162] Furthermore, the drying completion process is a finishing operation. In the finishing operation, the drying mode continues for a time set by the user, after which the dryer unit 10 stops operating. This allows the user to adjust the degree of drying of the clothes according to their preference.

[0163] Furthermore, the control device 30 does not necessarily need to have all of the first, second, third, and fourth conditions set. In other words, the control device 30 only needs to have one or more of the first, second, third, and fourth conditions set.

[0164] Furthermore, each function of the control device 30 in Embodiment 1 is realized by a processing circuit. Figure 17 is a configuration diagram showing a first example of a processing circuit that realizes each function of the control device 30 in Embodiment 1. The processing circuit 100 in the first example is dedicated hardware.

[0165] Furthermore, the processing circuit 100 can be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. In addition, each function of the control device 30 may be implemented by an individual processing circuit 100, or all functions may be implemented together by the processing circuit 100.

[0166] Figure 18 is a configuration diagram showing a second example of a processing circuit that realizes each function of the control device 30 of Embodiment 1. The processing circuit 200 of the second example includes a processor 201 and a memory 202.

[0167] Processor 201 can include, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a microprocessor, a microcontroller, or a DSP (Digital Signal Processor).

[0168] In the processing circuit 200, each function of the control device 30 is realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in memory 202. The processor 201 realizes each function by reading and executing the programs stored in memory 202.

[0169] The program stored in memory 202 can be said to cause the computer to execute the procedures or methods of each of the parts described above. Here, memory 202 refers to non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), and EEPROM (Electrically Erasable and Programmable Read Only Memory). Magnetic disks, flexible disks, optical disks, compact disks, minidiscs, DVDs, etc., also fall under the category of memory 202.

[0170] Furthermore, some of the functions of the above-mentioned parts may be implemented using dedicated hardware, while others may be implemented using software or firmware.

[0171] Thus, the processing circuit can realize the functions of each of the parts described above through hardware, software, firmware, or a combination thereof.

[0172] Although preferred embodiments have been described in detail above, the invention is not limited to the embodiments described above, and various modifications and substitutions can be made to the embodiments described above without departing from the scope of the claims.

[0173] The various aspects of this disclosure are summarized below as an appendix.

[0174] (Note 1) A dryer body having a blower and a heater, and A control device that controls the dryer unit using multiple operating modes, including a drying mode for drying clothes in the bathroom. Equipped with, In the drying operation mode, the control device With the heater turned off, ventilation is performed using the fan, and the convergence prediction value of the absolute humidity inside the bathroom is estimated from the exponential decay of the absolute humidity inside the bathroom. After calculating the estimated absolute humidity outside the bathroom, the heater is turned on. A bathroom heating, ventilation, and drying machine that uses the estimated value to determine if the clothes are dry. (Note 2) The control device calculates the estimated value by estimating two or more convergence prediction values ​​for two or more ventilation airflow rates, as described in Appendix 1 of the bathroom heating, ventilation, and drying machine. (Note 3) A dryer body having a blower and a heater, and A control device that controls the dryer unit using multiple operating modes, including a drying mode for drying clothes in the bathroom. Equipped with, The control device has one or more conditions set for determining whether the clothes are dry. The one or more of the above conditions include the condition that, after the slope of the absolute humidity in the bathroom becomes a negative value, the absolute humidity in the bathroom passes through an inflection point, or the slope of the absolute humidity in the bathroom passes through a minimum value. The control device is a bathroom heating, ventilation, and drying machine that, in the drying determination, proceeds to the drying completion process after all one or more of the above conditions have been met. (Note 4) A dryer body having a blower and a heater, and A control device that controls the dryer unit using multiple operating modes, including a drying mode for drying clothes in the bathroom. Equipped with, The control device has one or more conditions set for determining whether the clothes are dry. The one or more of the above conditions include: The condition includes at least one of the following two conditions: the physical quantity obtained by dividing the difference between the current absolute humidity inside the bathroom and the estimated absolute humidity outside the bathroom by the difference between the current saturated absolute humidity calculated from the temperature inside the bathroom and the initial value of the saturated absolute humidity is less than or equal to an error threshold; and the absolute value of the slope of the physical quantity is less than or equal to a slope threshold. The control device is a bathroom heating, ventilation, and drying machine that, in the drying determination, proceeds to the drying completion process after all one or more of the above conditions have been met. (Note 5) A dryer body having a blower and a heater, and A control device that controls the dryer unit using multiple operating modes, including a drying mode for drying clothes in the bathroom. Equipped with, The control device has one or more conditions set for determining whether the clothes are dry. Let F be the current saturated absolute humidity calculated from the temperature inside the bathroom, let F0 be the initial value of the saturated absolute humidity, let R be the current relative humidity inside the bathroom, and let X0 be the estimated absolute humidity outside the bathroom, with R0 = X0 / F0. The one or more of the above conditions include: The condition includes the requirement that the absolute value of the slope of the physical quantity ((FR-F0R0)(F0R-FR0)) / ((R-R0)(F-F0)) is less than or equal to the judgment threshold. The control device is a bathroom heating, ventilation, and drying machine that, in the drying determination, proceeds to the drying completion process after all one or more of the above conditions have been met. (Note 6) A dryer body having a blower and a heater, and A control device that controls the dryer unit using multiple operating modes, including a drying mode for drying clothes in the bathroom. Equipped with, The control device has one or more conditions set for determining whether the clothes are dry. The one or more of the above conditions include: The first condition is that after the slope of the absolute humidity in the bathroom becomes a negative value, the absolute humidity in the bathroom passes through an inflection point, or the slope of the absolute humidity in the bathroom passes through a minimum value. A second condition is that the difference between the current absolute humidity inside the bathroom and the estimated absolute humidity outside the bathroom, divided by the difference between the current saturated absolute humidity calculated from the temperature inside the bathroom and the initial value of the saturated absolute humidity, is less than or equal to an error threshold; and a third condition is that the absolute value of the slope of the physical quantity is less than or equal to a slope threshold; and at least one of these conditions is met. Let F be the current saturated absolute humidity calculated from the temperature inside the bathroom, let F0 be the initial value of the saturated absolute humidity, let R be the current relative humidity inside the bathroom, and let X0 be the estimated absolute humidity outside the bathroom, with R0 = X0 / F0. The fourth condition is that the absolute value of the slope of the physical quantity ((FR-F0R0)(F0R-FR0)) / ((R-R0)(F-F0)) is less than or equal to the judgment threshold. The control device is a bathroom heating, ventilation, and drying machine that, in the drying determination, proceeds to the drying completion process after all one or more of the above conditions have been met. (Note 7) A dryer body having a blower and a heater, and A control device that controls the dryer unit using multiple operating modes, including a drying mode for drying clothes in the bathroom. Equipped with, The control device has one or more conditions set for determining whether the clothes are dry. The control device is For each of the one or more conditions mentioned above, the current value of the heater is accumulated while the condition is met, and when the condition is no longer met, the accumulated value of the heater's current is reset. A bathroom heating, ventilation, and drying machine that, when the cumulative value for all one or more of the above conditions exceeds a heat threshold, proceeds to the drying completion process. (Note 8) The control device is For each of the one or more conditions mentioned above, the current value of the heater is accumulated while the condition is met, and when the condition is no longer met, the accumulated value of the heater's current is reset. A bathroom heating, ventilation, and drying machine as described in any one of the items in Appendix 3 to Appendix 6, which proceeds to the drying termination process when the cumulative value exceeds the heat threshold for all of the above one or more conditions. (Note 9) The bathroom heating, ventilation and drying machine described in any one of the appendices 3 to 8, wherein the drying completion process is a process in which the drying operation mode is continued for a time set by the user, and then a finishing operation is performed to stop the operation of the dryer unit. [Explanation of Symbols]

[0175] 10 Dryer unit, 21 Blower, 25 Heater, 30 Control unit, 50 Bathroom heating, ventilation, and drying unit, 60 Bathroom.

Claims

1. A dryer body having a blower and a heater, and A control device that controls the dryer unit using multiple operating modes, including a drying mode for drying clothes in the bathroom. Equipped with, In the drying operation mode, the control device With the heater turned off, ventilation is performed using the fan, and the convergence prediction value of the absolute humidity inside the bathroom is estimated from the exponential decay of the absolute humidity inside the bathroom. After calculating the estimated absolute humidity outside the bathroom, the heater is turned on. A bathroom heating, ventilation, and drying machine that uses the estimated value to determine if the clothes are dry.

2. The bathroom heating, ventilation, and drying machine according to claim 1, wherein the control device calculates the estimated value by estimating two or more convergence prediction values ​​for two or more ventilation airflow rates.

3. A dryer body having a blower and a heater, and A control device that controls the dryer unit using multiple operating modes, including a drying mode for drying clothes in the bathroom. Equipped with, The control device has one or more conditions set for determining whether the clothes are dry. The one or more of the above conditions include the condition that, after the slope of the absolute humidity in the bathroom becomes a negative value, the absolute humidity in the bathroom passes through an inflection point, or the slope of the absolute humidity in the bathroom passes through a minimum value. The control device is a bathroom heating, ventilation, and drying machine that, in the drying determination, proceeds to the drying completion process after all one or more of the above conditions have been met.

4. A dryer body having a blower and a heater, and A control device that controls the dryer unit using multiple operating modes, including a drying mode for drying clothes in the bathroom. Equipped with, The control device has one or more conditions set for determining whether the clothes are dry. The one or more of the above conditions include: The condition includes at least one of the following two conditions: the physical quantity obtained by dividing the difference between the current absolute humidity inside the bathroom and the estimated absolute humidity outside the bathroom by the difference between the current saturated absolute humidity calculated from the temperature inside the bathroom and the initial value of the saturated absolute humidity is less than or equal to an error threshold; and the absolute value of the slope of the physical quantity is less than or equal to a slope threshold. The control device is a bathroom heating, ventilation, and drying machine that, in the drying determination, proceeds to the drying completion process after all one or more of the above conditions have been met.

5. A dryer body having a blower and a heater, and A control device that controls the dryer unit using multiple operating modes, including a drying mode for drying clothes in the bathroom. Equipped with, The control device has one or more conditions set for determining whether the clothes are dry. Let F be the current saturated absolute humidity calculated from the temperature inside the bathroom, and let F be the initial value of saturated absolute humidity. ０ Let R be the current relative humidity inside the bathroom, and X be the estimated absolute humidity outside the bathroom. ０ Toshi, R ０ = X ０ / F ０ In that case, The one or more of the above conditions include: The physical quantity ((FR - F ０ R ０ )(F ０ R - FR ０ )) / ((R - R ０ )(F - F ０ )) includes the condition that the absolute value of the slope becomes less than or equal to the determination threshold value. The control device is a bathroom heating, ventilation, and drying machine that, in the drying determination, proceeds to the drying completion process after all one or more of the above conditions have been met.

6. A dryer body having a blower and a heater, and A control device that controls the dryer unit using multiple operating modes, including a drying mode for drying clothes in the bathroom. Equipped with, The control device has one or more conditions set for determining whether the clothes are dry. The one or more of the above conditions include: The first condition is that after the slope of the absolute humidity in the bathroom becomes a negative value, the absolute humidity in the bathroom passes through an inflection point, or the slope of the absolute humidity in the bathroom passes through a minimum value. A second condition is that the difference between the current absolute humidity inside the bathroom and the estimated absolute humidity outside the bathroom, divided by the difference between the current saturated absolute humidity calculated from the temperature inside the bathroom and the initial value of saturated absolute humidity, is less than or equal to an error threshold; and a third condition is that the absolute value of the slope of the physical quantity is less than or equal to a slope threshold; and at least one of these conditions is met. Let F be the current saturated absolute humidity calculated from the temperature inside the bathroom, and let F be the initial value of the saturated absolute humidity. ０ Let R be the current relative humidity inside the bathroom, and X be the estimated absolute humidity outside the bathroom. ０ Toshi, R ０ = X ０ / F ０ In that case, Physical quantity ((FR-F ０ R ０ )(F ０ R-FR ０ )) / ((R-R ０ )(F-F ０ The fourth condition is that the absolute value of the slope of )) is less than or equal to the judgment threshold. The control device is a bathroom heating, ventilation, and drying machine that, in the drying determination, proceeds to the drying completion process after all one or more of the above conditions have been met.

7. A dryer body having a blower and a heater, and A control device that controls the dryer unit using multiple operating modes, including a drying mode for drying clothes in the bathroom. Equipped with, The control device has one or more conditions set for determining whether the clothes are dry. The control device is For each of the one or more conditions mentioned above, the current value of the heater is accumulated while the condition is met, and when the condition is no longer met, the accumulated value of the heater's current is reset. A bathroom heating, ventilation, and drying machine that, when the cumulative value for all one or more of the above conditions exceeds a heat threshold, proceeds to the drying completion process.

8. The control device is For each of the one or more conditions mentioned above, the current value of the heater is accumulated while the condition is met, and when the condition is no longer met, the accumulated value of the heater's current is reset. A bathroom heating, ventilation, and drying machine according to any one of claims 3 to 6, wherein when the cumulative value for all one or more of the above conditions exceeds a heat threshold, the machine proceeds to the drying completion process.

9. The bathroom heating, ventilation and drying machine according to any one of claims 3 to 7, wherein the drying completion process is a process of performing a finishing operation in which the operation of the dryer body is stopped after continuing the drying operation mode for a time set by the user.

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