Dehumidifier and control method thereof

Abstract

The present application relates to the technical field of household appliances, in particular to a dehumidifier and a control method thereof. The control method of the dehumidifier comprises: obtaining the temperature of an evaporator to obtain a first temperature; in response to the first temperature of the evaporator being less than a first preset temperature, obtaining the weight of a condensate water collecting device; and determining whether the evaporator meets a first defrosting condition according to the weight. In the control method, when the first temperature of the evaporator is less than the first preset temperature, the weight of the condensate water collecting device is used to determine the frosting condition of the evaporator, which can improve the accuracy of defrosting determination, thereby reducing the possibility of invalid defrosting, and further avoiding the problem of reduced dehumidification efficiency caused by too long defrosting time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of household appliances, in particular to a dehumidifier and a control method thereof. BACKGROUND

[0002] At present, when the dehumidifier is running, the temperature of the evaporator surface will decrease with the decrease of the ambient temperature, especially under the condition of medium and low temperature, the temperature of the evaporator will even decrease to below 0℃, and after running in this state for a period of time, the condensate water is easy to frost or even freeze on the evaporator surface, and the frost layer with increasing thickness not only hinders the heat transfer between the evaporator and the air, but also reduces the circulation area of the air supply, eventually leading to serious attenuation of the dehumidification capacity, and the dehumidifier has to perform defrosting operation.

[0003] The existing dehumidifier defrosting method mainly determines through the evaporator coil temperature, and performs defrosting action after a fixed preset time, that is, when the evaporator coil temperature is lower than a certain preset temperature, it means that the evaporator has the risk of frosting, and after a fixed preset time, the frost layer has basically formed, so the defrosting action is performed.

[0004] Due to different temperature and humidity of the dehumidifier running condition, the frosting speed of the evaporator surface is different, the thickness of the frost layer after a fixed preset frosting time is different, the preset time is too long, which will lead to too thick frost layer under the condition of low temperature and high humidity, and serious attenuation of dehumidification capacity; the preset time is too short, which will lead to that the actual frost layer is not formed or the frost layer is too thin under the condition of medium temperature and low humidity, the defrosting time ratio in the running period increases, and the dehumidification efficiency decreases. Therefore, the influence of the running environment on the growth of the frost layer is ignored during the current frosting determination, which leads to that the frosting determination does not match the actual frosting condition, and the defrosting period ratio is unreasonable; that is to say, the existing defrosting determination method has the problem of low accuracy of defrosting determination, which easily leads to invalid defrosting caused by defrosting misjudgment. SUMMARY

[0005] In view of the above problems, the present application is proposed to provide a dehumidifier and a control method thereof which can overcome the above problems or at least partially solve the above problems, and aims to solve the problem of low accuracy of defrosting determination of the existing dehumidifier, so as to achieve the purpose of improving the accuracy of defrosting determination.

[0006] In one aspect, the present application provides a control method of a dehumidifier, comprising:

[0007] obtaining the temperature of the evaporator to obtain a first temperature;

[0008] in response to the first temperature of the evaporator being less than a first preset temperature, obtaining the weight of the condensate water collecting device;

[0009] determining whether the evaporator meets a first defrosting condition according to the weight.

[0010] Optionally, the control method further comprises:

[0011] in response to the first temperature of the evaporator being less than the first preset temperature, obtaining a first dew point temperature of a running environment;

[0012] in response to the evaporator satisfying a first defrosting condition, obtaining a second dew point temperature of the running environment;

[0013] determining whether the evaporator satisfies a second defrosting condition according to the first dew point temperature and the second dew point temperature.

[0014] Optionally, the determining whether the evaporator satisfies the first defrosting condition according to the weight comprises:

[0015] determining whether the evaporator satisfies the first defrosting condition according to an increasing speed of the weight;

[0016] if the increasing speed of the weight decreases, determining that the evaporator satisfies the first defrosting condition.

[0017] Optionally, the determining that the evaporator satisfies the first defrosting condition if the increasing speed of the weight decreases comprises:

[0018] obtaining the weight every first preset time, calculating a difference between two adjacent weights, and taking the first calculated difference as a first difference and the Nth calculated difference as an Nth difference, where N≥2;

[0019] when a ratio of the Nth difference to the first difference is less than or equal to a preset value, determining that the evaporator satisfies the first defrosting condition.

[0020] Optionally, the determining whether the evaporator satisfies the second defrosting condition according to the first dew point temperature and the second dew point temperature comprises:

[0021] calculating a temperature difference between the second dew point temperature and the first dew point temperature;

[0022] when the temperature difference is less than or equal to a preset temperature difference value, determining that the evaporator satisfies the second defrosting condition.

[0023] Optionally, when the temperature difference is greater than the preset temperature difference value, re-obtaining the first temperature after a second preset time.

[0024] Optionally, the control method further comprises:

[0025] defrosting the evaporator when the evaporator satisfies the first defrosting condition, or when the evaporator satisfies the second defrosting condition;

[0026] the defrosting the evaporator comprises:

[0027] controlling the refrigerant to circulate in a first direction opposite to a direction of circulation of the refrigerant when the dehumidifier is in the dehumidifying operation, and / or controlling the fan to rotate in a second direction opposite to a direction of rotation of the fan when the dehumidifier is in the dehumidifying operation.

[0028] Optionally, the defrosting the evaporator further comprises:

[0029] The first operating frequency of the compressor and the second temperature of the evaporator are obtained before the controlling the refrigerant to circulate in the first direction and / or the controlling the fan to rotate in the second direction.

[0030] The compressor is controlled to operate at a preset frequency when the refrigerant is controlled to circulate in the first direction and the fan is controlled to rotate in the second direction, and the preset frequency is inversely related to the second temperature of the evaporator.

[0031] Optionally, the third dry-bulb temperature of an operating environment is obtained before the controlling the refrigerant to circulate in the first direction and / or the controlling the fan to rotate in the second direction.

[0032] The compressor is controlled to operate at a preset frequency when the refrigerant is controlled to circulate in the first direction and the fan is controlled to rotate in the second direction, and the preset frequency is inversely related to the second temperature of the evaporator.

[0033] The temperature of the evaporator is obtained to obtain a third temperature.

[0034] It is determined whether the third temperature is greater than or equal to a second preset temperature, and the second preset temperature is positively related to the third dry-bulb temperature.

[0035] If yes, the dehumidifier is controlled to operate in the dehumidifying operation after a third preset time, and the compressor is controlled to operate at the first operating frequency.

[0036] The application further provides a dehumidifier, which comprises a control device, the control device comprising a memory and a processor, and the memory storing a control program, and the control program being executed by the processor to control the dehumidifier according to any one of the control methods.

[0037] In the control method, when the first temperature of the evaporator is less than a first preset temperature, the frosting condition of the evaporator is determined by the weight of the condensate water collection device, which can improve the accuracy of defrosting determination, thereby reducing the possibility of invalid defrosting, and further avoiding the problem of reduced dehumidifying efficiency due to too long defrosting time.

[0038] Therefore, the above and other objects, advantages and features of the application will become more apparent from the following detailed description of specific embodiments of the application, when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0039] Some specific embodiments of the present application will be described in detail in the following with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar components or parts. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the drawings:

[0040] Figure 1 is a schematic flow chart of a control method of a dehumidifier according to an embodiment of the present application;

[0041] Figure 2 is a schematic flow chart of a control method of a dehumidifier according to another embodiment of the present application;

[0042] Figure 3 is a schematic flow chart of a control method of a dehumidifier according to another embodiment of the present application;

[0043] Figure 4 is a schematic schematic diagram of a dehumidifier according to an embodiment of the present application;

[0044] Figure 5 is a schematic schematic diagram of a dehumidifier according to another embodiment of the present application;

[0045] Figure 6 is a schematic use state diagram of a dehumidifier in dehumidifying operation according to another embodiment of the present application;

[0046] Figure 7 is a schematic use state diagram of a dehumidifier in defrosting operation according to another embodiment of the present application. DETAILED DESCRIPTION

[0047] In the description of the present embodiments, references to "one embodiment", "some embodiments", "an exemplary embodiment", "an example", "a specific example", or "some examples" mean that a particular feature, structure, material or characteristic is included in at least one embodiment or example of the present application. The appearances of the phrases "in one embodiment" or "in some embodiments" in various places in the specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0048] Figure 1 is a schematic flow chart of a control method of a dehumidifier according to an embodiment of the present application, and in combination with Figures 2-7 The present application provides a control method of a dehumidifier, the control method comprising the following steps:

[0049] obtaining a temperature of the evaporator to obtain a first temperature;

[0050] In response to the first temperature of the evaporator being less than the first preset temperature, a weight of the condensed water collecting device is obtained;

[0051] It is determined whether the evaporator meets a first defrosting condition according to the weight.

[0052] Specifically, the control method comprises the following steps:

[0053] In step S11, a temperature of the evaporator is obtained to obtain a first temperature;

[0054] In step S12, it is determined whether the first temperature is less than a first preset temperature;

[0055] In step S13, if yes, a weight of the condensed water collecting device is obtained;

[0056] In step S14, it is determined whether the evaporator meets a first defrosting condition according to the weight.

[0057] Specifically, the condensed water collecting device is used for collecting condensed water. A weight sensor is arranged on the condensed water collecting device to obtain the weight of the condensed water collecting device. The first preset temperature is -3-0℃ (for example, -3℃, -2℃, -1℃ or 0℃).

[0058] In the embodiment, when the first temperature of the evaporator is less than the first preset temperature, it indicates that there is a risk of frosting on the surface of the evaporator. With the formation of the frost layer on the surface of the evaporator, the heat exchange effect between the refrigerant and the air becomes poor, the flow area of the air supply is reduced, and the dehumidification capacity of the dehumidifier is reduced. The most direct performance is that the weight of the condensed water in the condensed water collecting device increases at a slower speed. Therefore, when the first temperature of the evaporator is less than the first preset temperature, the frosting condition of the evaporator is determined by the weight of the condensed water collecting device, which can improve the accuracy of the defrosting determination, thereby reducing the possibility of invalid defrosting, and further avoiding the problem of dehumidification efficiency reduction caused by too long defrosting time.

[0059] As shown in FIG. 1, Figure 2 In some optional embodiments of the present application, the control method further comprises:

[0060] In response to the first temperature of the evaporator being less than the first preset temperature, a first dew point temperature of a running environment is obtained;

[0061] In response to the evaporator meeting the first defrosting condition, a second dew point temperature of the running environment is obtained;

[0062] It is determined whether the evaporator meets a second defrosting condition according to the first dew point temperature and the second dew point temperature.

[0063] Specifically, the control method comprises the following steps:

[0064] Step S21, obtaining the temperature of the evaporator to obtain a first temperature;

[0065] Step S22, judging whether the first temperature is less than the first preset temperature;

[0066] Step S23, if yes, obtaining the dew point temperature of the running environment to obtain a first dew point temperature, and obtaining the weight of the condensed water collecting device;

[0067] Step S24, judging whether the evaporator meets the first defrosting condition according to the weight;

[0068] Step S25, if yes, obtaining the dew point temperature of the running environment to obtain a second dew point temperature;

[0069] Step S26, judging whether the evaporator meets the second defrosting condition according to the first dew point temperature and the second dew point temperature.

[0070] Since the dehumidification capacity of the dehumidifier will decrease when the dew point temperature of the running environment of the dehumidifier decreases, at this time, it is not possible to judge whether the condensed water drainage speed is slow due to the frosting of the evaporator or due to the sudden decrease of the running environment temperature. That is to say, when the second dew point temperature is less than the first dew point temperature, the dehumidification capacity of the dehumidifier will decrease, thereby reducing the formation of condensed water, and further reducing the increasing speed of the weight of the condensed water collecting device. At this time, it is not possible to distinguish whether the increasing speed of the weight of the condensed water collecting device is reduced due to the frosting of the evaporator or due to the decrease of the dew point temperature of the running environment. Therefore, the present application judges whether the evaporator meets the second defrosting condition according to the dew point temperature of the running environment when the evaporator meets the first defrosting condition, and performs defrosting when the second defrosting condition is met.

[0071] In the present embodiment, the control method of the dehumidifier includes the first defrosting condition and the second defrosting condition, and the defrosting is started only when the first defrosting condition and the second defrosting condition are met at the same time. That is to say, in the present embodiment, it is firstly judged whether the evaporator meets the first defrosting condition, and then it is judged whether the evaporator meets the second defrosting condition after the evaporator meets the first defrosting condition. Therefore, the present embodiment can exclude the case that the increasing speed of the weight of the condensed water collecting device is reduced due to the decrease of the dew point temperature of the running environment, prevent the misjudgment of the frosting condition, thereby avoiding the case that the actual frost layer is not formed or the frost layer is too thin, and further improving the accuracy of the defrosting judgment, further avoiding the invalid defrosting, and further reasonably optimizing the proportion of the defrosting period, and increasing the dehumidification efficiency of the dehumidifier under the low temperature working condition.

[0072] In some optional embodiments of the present application, the judging whether the evaporator meets the first defrosting condition according to the weight comprises:

[0073] determining whether the evaporator meets a first defrosting condition according to the increasing speed of the weight;

[0074] determining that the evaporator meets the first defrosting condition if the increasing speed of the weight decreases.

[0075] Further, in some optional embodiments of the present application, the determining that the evaporator meets the first defrosting condition if the increasing speed of the weight decreases includes:

[0076] acquiring the weight every first preset time, calculating the difference between the two adjacent weights, and recording the first calculated difference as a first difference and the Nth calculated difference as an Nth difference, wherein N≥2;

[0077] determining that the evaporator meets the first defrosting condition when the ratio of the Nth difference to the first difference is less than or equal to a preset value.

[0078] Specifically, the ratio of the Nth difference to the first difference refers to the level of the current calculated weight difference deviating from the weight difference when the evaporator is just (un) frosted. The ratio of the Nth difference to the first difference can be a percentage. If the ratio of the Nth difference to the first difference is larger, it indicates that the dehumidification amount is less affected and the frosting condition is slight; if the ratio of the Nth difference to the first difference is smaller, it indicates that the dehumidification amount is seriously attenuated and the frosting condition is serious. Therefore, the preset value can be determined by the critical condition of acceptable frosting.

[0079] Preferably, the preset value is 8%-30% (for example: 8%, 10%, 12%, 14%, 18%, 20%, 25% or 30%). Further preferably, the preset value is 10%. Further, in some optional embodiments of the present application, the determining whether the evaporator meets the second defrosting condition according to the first dew point temperature and the second dew point temperature includes:

[0080] calculating the temperature difference between the second dew point temperature and the first dew point temperature;

[0081] determining that the evaporator meets the second defrosting condition when the temperature difference is less than or equal to a preset temperature difference value.

[0082] Specifically, the preset temperature difference value is -2℃-10℃ (for example: -2℃, -1℃, 0℃, 1℃, 2℃, 3℃, 4℃, 5℃, 6℃, 7℃, 8℃ or 10℃). Preferably, the preset temperature difference value is 0-8℃. Further preferably, the preset temperature difference value is 6℃.

[0083] Further, in some optional embodiments of the present application, the control method further includes: when the temperature difference is greater than the preset temperature difference value, re-acquiring the first temperature after a second preset time.

[0084] Specifically, the determining whether the evaporator meets the second defrosting condition according to the first dew point temperature and the second dew point temperature specifically comprises the following steps:

[0085] calculating a temperature difference between the second dew point temperature and the first dew point temperature;

[0086] determining whether the temperature difference is less than or equal to a preset temperature difference value;

[0087] if yes, determining that the evaporator meets the second defrosting condition; if no, determining that the evaporator does not meet the second defrosting condition, and reacquiring the first temperature after a second preset time.

[0088] In the embodiment, if the evaporator does not meet the second defrosting condition, it indicates that the dew point temperature of the running environment changes greatly, so that the machine can be excluded from the cooling effect of the running environment after the second preset time, and the frosting determination is re-performed. That is, if the determination of the dehumidifier defrosting is not effective, it indicates that the running temperature condition of the dehumidifier changes greatly in the determination time period, so that the dehumidifier can be excluded from the cooling effect of the running environment after the dehumidifier is stably operated, and the frosting determination is re-performed.

[0089] Further, the second preset time is 2-5 min (for example, 1 min, 2 min, 3 min, 4 min or 5 min). Preferably, the second preset time is 3 min.

[0090] In some optional embodiments of the present application, the first dew point temperature of the running environment is acquired, comprising:

[0091] acquiring a dry-bulb temperature of the running environment to obtain a first dry-bulb temperature, and acquiring a relative humidity of the running environment to obtain a first relative humidity;

[0092] calculating the first dew point temperature according to the first dry-bulb temperature and the first relative humidity.

[0093] The second dew point temperature of the running environment is acquired, comprising:

[0094] acquiring a dry-bulb temperature of the running environment to obtain a second dry-bulb temperature, and acquiring a relative humidity of the running environment to obtain a second relative humidity;

[0095] calculating the second dew point temperature according to the second dry-bulb temperature and the second relative humidity.

[0096] Specifically, the specific method for calculating the dew point temperature according to the dry-bulb temperature and the relative humidity is that the dew point temperature is obtained from the monitoring values of the dry-bulb temperature and the relative humidity of the corresponding environment, and the corresponding relationship between the parameters can be preset in the storage unit of the dehumidifier after referring to the wet air property parameter chart.

[0097] In some alternative embodiments of the present application, defrosting the evaporator includes: controlling the refrigerant to circulate in a first direction, wherein the first direction is opposite to the direction of circulation of the refrigerant when the dehumidifier is in dehumidifying operation.

[0098] The defrosting of the evaporator includes: controlling the refrigerant to circulate in a first direction, and controlling the fan to rotate in a second direction, wherein the first direction is opposite to the direction of circulation of the refrigerant when the dehumidifier is in dehumidifying operation, and the second direction is opposite to the direction of rotation of the fan when the dehumidifier is in dehumidifying operation.

[0099] Specifically, during the defrosting operation, the refrigerant discharged by the compressor passes through the evaporator, the throttling device and the condenser of the dehumidifier in turn and returns to the compressor. The air first flows through the condenser and then flows through the evaporator. The high-temperature refrigerant condenses and dissipates heat in the evaporator (which functions as a condenser at this time) while quickly melting the frost, and then evaporates and absorbs heat in the condenser (which functions as an evaporator at this time) while cooling and dehumidifying, thereby achieving complete defrosting and ensuring normal operation of the dehumidifying function.

[0100] Therefore, compared with the method of defrosting by controlling the compressor to stop and the fan to continue running, on the one hand, in the present embodiment, the refrigerant is controlled to circulate in a first direction during the defrosting of the evaporator, which utilizes the high-temperature and high-pressure refrigerant of the compressor to defrost the evaporator. The temperature of the refrigerant discharged by the compressor is significantly higher than the ambient temperature, which can significantly improve the defrosting efficiency and ensure the defrosting effect. On the other hand, in the present embodiment, the fan is controlled to rotate in a second direction during the defrosting of the evaporator, thereby realizing simultaneous defrosting and dehumidifying, and further increasing the dehumidifying efficiency under low-temperature operating conditions of the dehumidifier.

[0101] In some alternative embodiments of the present application, the defrosting of the evaporator includes: controlling the refrigerant to circulate in a first direction, wherein the first direction is opposite to the direction of circulation of the refrigerant when the dehumidifier is in dehumidifying operation.

[0102] In some alternative embodiments of the present application, the defrosting of the evaporator includes: controlling the fan to rotate in a second direction, wherein the second direction is opposite to the direction of rotation of the fan when the dehumidifier is in dehumidifying operation.

[0103] In some alternative embodiments of the present application, the defrosting of the evaporator includes: defrosting by controlling the compressor to stop and the fan to continue running. That is, after the compressor stops, the fan forced convection is used to melt the frost layer on the surface of the evaporator.

[0104] In some alternative embodiments of the present application, the defrosting of the evaporator further includes:

[0105] The first operating frequency of the compressor and the second temperature of the evaporator are obtained before the refrigerant is circulated in the first direction and / or the fan is rotated in the second direction.

[0106] The preset frequency of the compressor is controlled to operate when the refrigerant is circulated in the first direction and the fan is rotated in the second direction, and the preset frequency is inversely related to the second temperature of the evaporator.

[0107] Specifically, the second temperature of the evaporator is obtained by obtaining the temperature of the evaporator.

[0108] In the embodiment, the preset frequency of the compressor is determined by the second temperature of the evaporator before the defrosting operation is performed when the refrigerant is circulated in the first direction (i.e. reverse circulation). The lower the second temperature, the higher the preset frequency of the compressor during reverse circulation. Through the above setting, it is beneficial to obtain a higher compressor discharge temperature and accelerate the speed of refrigerant defrosting.

[0109] For example, the corresponding relationship between the preset frequency of the compressor and the second temperature of the evaporator can be shown in Table 1 below, wherein the second preset frequency > the first preset frequency > the first frequency of the compressor when the refrigerant is circulated in the forward direction.

[0110] Table 1

[0111] Second temperature of evaporator (-5，0℃) ≤-5℃ Compressor operating frequency First preset frequency Second preset frequency

[0112] Further, in some optional embodiments of the present application, the defrosting of the evaporator further comprises:

[0113] The third dry-bulb temperature of the operating environment is obtained before the refrigerant is circulated in the first direction and / or the fan is rotated in the second direction.

[0114] After the compressor is controlled to operate at the preset frequency, the following steps are further included:

[0115] The temperature of the evaporator is obtained to obtain a third temperature.

[0116] It is determined whether the third temperature is greater than or equal to a second preset temperature, and the second preset temperature is positively related to the third dry-bulb temperature.

[0117] If yes, the dehumidifier is controlled to operate after a third preset time, and the compressor is controlled to operate at the first operating frequency.

[0118] In this embodiment, the "positive correlation between the second preset temperature and the third dry-bulb temperature" specifically means that the second preset temperature increases as the ambient temperature monitoring value increases, and the correspondence between the two can be referred to in Table 2 below. This control strategy can avoid the negative impact of the residual heat in the evaporator after defrosting on the positive circulation cooling and dehumidification of the refrigerant under different operating temperature conditions.

[0119] Table 2

[0120] Third dry-bulb temperature ≤5℃ (5，10℃] ＞10℃ Second preset temperature 3℃ 5℃ 7℃

[0121] Because the temperature rise of the coil may be faster than the melting rate of the frost when defrosting by dissipating heat from the inside to the outside of the evaporator coil through the high-temperature refrigerant, in order to ensure complete frost melting, the refrigerant needs to continue to circulate in reverse when the third temperature (e.g., the pipe temperature monitoring value) reaches the second preset temperature. The defrosting operation will then stop after a third preset time. The third preset time is 30-90 seconds (e.g., 30 seconds, 40 seconds, 50 seconds, 60 seconds, 70 seconds, 80 seconds, or 90 seconds).

[0122] In some alternative embodiments, defrosting the evaporator further includes:

[0123] Determine whether the third temperature is greater than or equal to the second preset temperature;

[0124] If so, after a third preset time, the dehumidifier is controlled to dehumidify, and the compressor operates at the second operating frequency.

[0125] Specifically, the second operating frequency is equal to the first operating frequency; or the second operating frequency is greater than the first operating frequency; or the second operating frequency is less than the first operating frequency.

[0126] In some preferred embodiments of the present invention, the control method mainly includes the following steps:

[0127] Step S31, dehumidification operation under medium and low temperature conditions;

[0128] Step S32: Determine the conditions for frosting.

[0129] Step S33: If the conditions in S32 are met, perform the defrosting action and simultaneously perform normal dehumidification.

[0130] Step S34: Determine the defrost exit conditions;

[0131] Step S35: If the conditions in S34 are met, end the defrosting operation and restore the original dehumidification operation.

[0132] like Figure 3 As shown, specifically, the control methods for a dehumidifier include:

[0133] when the dehumidifier is running in the medium-low temperature working condition, judging whether the first temperature of the evaporator is less than a first preset temperature (in this embodiment, 0℃);

[0134] If yes, obtaining the first dry-bulb temperature and the first relative humidity of the running environment, and calculating a first dew-point temperature according to the first dry-bulb temperature and the first relative humidity, denoted as T 露1 ;

[0135] obtaining the weight of the condensate collecting device, and calculating the difference ΔG between the adjacent two weight monitoring values (specifically, such as ΔG1=G2-G1, ΔG2=G3-G2, … ΔG n =G n+1 -G n );

[0136] judging whether ΔGn / ΔG1 is less than or equal to a preset value;

[0137] If yes, obtaining the second dry-bulb temperature and the second relative humidity of the running environment, and calculating a second dew-point temperature according to the second dry-bulb temperature and the second relative humidity, denoted as T 露2 ;

[0138] judging the temperature difference between the calculated second dew-point temperature and the first dew-point temperature, the temperature difference = T 露2 -T 露1 , and judging whether the temperature difference is less than or equal to a preset temperature difference value;

[0139] If yes, obtaining the first running frequency of the compressor and the third dry-bulb temperature of the running environment;

[0140] controlling the refrigerant to circulate in the first direction (i.e., controlling the refrigerant to circulate in the reverse direction), controlling the fan to rotate in the second direction (i.e., controlling the fan to rotate in the reverse direction), and controlling the compressor to run at a preset frequency;

[0141] judging whether the third temperature of the evaporator is greater than or equal to a second preset temperature;

[0142] If yes, after a third preset time, controlling the refrigerant to circulate in the third direction (i.e., controlling the refrigerant to circulate in the forward direction), controlling the fan to rotate in the fourth direction (i.e., controlling the fan to rotate in the forward direction), and controlling the compressor to run at the first running frequency.

[0143] In this embodiment, the control method of the dehumidifier further comprises: when the dehumidifier is running in the medium-low temperature working condition, judging whether the first temperature of the evaporator is less than a first preset temperature (in this embodiment, 0℃); if no, the dehumidifier continues to run.

[0144] For example, Figures 4-7As shown, the present invention provides a dehumidifier, the dehumidifier including a control device, the control device including a memory and a processor, the memory storing a control program, the control program being executed by the processor to implement the control method of the dehumidifier described in any of the above embodiments.

[0145] In some optional embodiments of the present invention, the dehumidifier further includes a compressor 1, an evaporator 3, a condenser 2, a fan 5, and a refrigerant flow control device 6.

[0146] Specifically, the evaporator 3 and condenser 2 are arranged side by side, and the fan 5 is located on the side of the condenser 2 away from the evaporator 3. The refrigerant flow control device is configured to: control the refrigerant to circulate in the third direction (i.e., control the refrigerant to circulate in the forward direction) when the dehumidifier is dehumidifying; and control the refrigerant to circulate in the first direction (i.e., control the refrigerant to circulate in the reverse direction) when the dehumidifier is defrosting.

[0147] In some optional embodiments of the present invention, the fan 5 is a reversible axial flow fan. The fan is configured such that: when the dehumidifier is dehumidifying, the fan 5 is controlled to rotate in a fourth direction (i.e., the fan is controlled to rotate in the forward direction); when the dehumidifier is defrosting, the fan 5 is controlled to rotate in a second direction (i.e., the fan is controlled to rotate in the reverse direction).

[0148] like Figure 4 As shown, in some optional embodiments of the present invention, the refrigerant flow control device 6 includes two three-way solenoid valves. Specifically, the three-way solenoid valves are two-position three-way solenoid valves. In some alternative embodiments of the present invention, such as Figure 5 As shown, the refrigerant flow control device 6 includes four two-way solenoid valves; or, the refrigerant flow control device includes various types of valves.

[0149] Specifically, the two three-way solenoid valves are designated as the first three-way solenoid valve and the second three-way solenoid valve. The three openings of the first three-way solenoid valve are connected to the inlet of condenser 2, the outlet of evaporator 3, and the outlet of compressor 1, respectively. The three openings of the second three-way solenoid valve are connected to the inlet of condenser 2, the outlet of evaporator 3, and the inlet of compressor 1, respectively.

[0150] During dehumidification operation, the on / off state of the refrigerant flow control device is as follows: Figure 6 As shown, black indicates a valve open in the pipeline, and white indicates a valve closed in the pipeline. When the dehumidifier is running, the refrigerant is discharged from the compressor 1 and passes through the condenser 2, the throttling device 4, and the evaporator 3 of the dehumidifier in sequence before returning to the compressor 1. In this state, the reversible axial flow fan runs in the forward direction, and the air flows through the evaporator 3 first and then through the condenser 2. Frost forms on the low-temperature surface of the evaporator 3.

[0151] During defrosting operation, the on / off status of the refrigerant flow control device is as follows:Figure 7 As shown, black represents the opening of the pipeline, and white represents the closing of the pipeline. When the dehumidifier is in the defrosting operation, the refrigerant discharged by the compressor 1 passes through the evaporator 3, the throttling device 4 and the condenser 2 of the dehumidifier in turn and returns to the compressor 1. In this state, the reversible axial flow fan is reversely operated, and the air flow passes through the condenser 2 and then the evaporator 3. The high-temperature refrigerant is condensed and radiated in the evaporator 3 (which functions as a condenser at this time) to quickly defrost, and then evaporates and absorbs heat in the condenser 2 (which functions as an evaporator at this time) to reduce temperature and dehumidify, thereby achieving the purpose of complete defrosting and ensuring the normal operation of the dehumidification function.

[0152] After determining that the defrosting is completed, the refrigerant flow control device is switched back to the dehumidifying operation state, and the reversible axial flow fan is positively operated.

[0153] In the embodiment, firstly, the refrigerant discharged by the compressor is obviously higher than the ambient temperature, and is directly introduced into the evaporator to achieve high-efficiency and rapid defrosting; secondly, by switching the switching state of the refrigerant flow control device and the operation direction of the axial flow fan, the dehumidifier can still ensure the normal realization of the dehumidification function during the defrosting operation; finally, the defrosting determination condition of the present application is closely related to the thickness of the frost layer, which improves the determination accuracy of the defrosting control method, reasonably optimizes the proportion of the defrosting period, and increases the dehumidification efficiency of the dehumidifier under low-temperature working conditions.

[0154] In some optional embodiments of the present application, a temperature and humidity sensor is arranged on the shell of the dehumidifier, and the dry-bulb temperature and the relative humidity of the operating environment are obtained through the temperature and humidity sensor. In some alternative embodiments, a temperature sensor and a humidity sensor are arranged on the shell of the dehumidifier, the dry-bulb temperature of the operating environment is obtained through the temperature sensor, and the relative humidity of the operating environment is obtained through the humidity sensor.

[0155] In some optional embodiments of the present application, the condensate water collecting device comprises a water tank for containing the condensate water. A weight sensor is arranged at the bottom of the water tank to weigh the weight of the water tank.

[0156] At this point, those skilled in the art should recognize that although the present application has been shown and described in detail in the above embodiments, many other variations or modifications can be directly determined or deduced according to the disclosure of the present application without departing from the spirit and scope of the present application, which conform to the principles of the present application. Therefore, the scope of the present application should be understood and recognized as covering all these other variations or modifications.

Claims

1. A control method of a dehumidifier, characterized by, The control method comprises: acquiring a temperature of the evaporator to obtain a first temperature; in response to the first temperature of the evaporator being less than a first preset temperature, acquiring a weight of the condensate collecting device; judging whether the evaporator meets a first defrosting condition according to an increasing speed of the weight; if the increasing speed of the weight decreases, judging that the evaporator meets the first defrosting condition.

2. The control method of a dehumidifier according to claim 1, characterized by, The control method further comprises: in response to the first temperature of the evaporator being less than the first preset temperature, acquiring a first dew point temperature of the operating environment; in response to the evaporator meeting the first defrosting condition, acquiring a second dew point temperature of the operating environment; judging whether the evaporator meets a second defrosting condition according to the first dew point temperature and the second dew point temperature.

3. The control method of the dehumidifier according to claim 1, wherein if the increasing speed of the weight decreases, judging that the evaporator meets the first defrosting condition comprises: acquiring the weight every first preset time, calculating a difference between two adjacent weights, and recording the first calculated difference as a first difference and the Nth calculated difference as an Nth difference, wherein N≥2; when a ratio of the Nth difference to the first difference is less than or equal to a preset value, judging that the evaporator meets the first defrosting condition.

4. The control method of the dehumidifier according to claim 2, wherein judging whether the evaporator meets the second defrosting condition according to the first dew point temperature and the second dew point temperature comprises: calculating a temperature difference between the second dew point temperature and the first dew point temperature; when the temperature difference is less than or equal to a preset temperature difference value, judging that the evaporator meets the second defrosting condition.

5. The control method of a dehumidifier according to claim 4, wherein The control method further comprises: when the temperature difference is greater than the preset temperature difference value, reacquiring the first temperature after a second preset time.

6. The control method of a dehumidifier according to claim 1 or 2, characterized by, The control method further comprises: after the evaporator meets the first defrosting condition, or after the evaporator meets the second defrosting condition, defrosting the evaporator; defrosting the evaporator comprises: controlling the refrigerant to circulate in a first direction, and / or controlling the fan to rotate in a second direction, wherein the first direction is opposite to a direction in which the refrigerant circulates when the dehumidifier is in a dehumidifying operation, and the second direction is opposite to a direction in which the fan circulates when the dehumidifier is in the dehumidifying operation.

7. The control method of the dehumidifier according to claim 6, wherein defrosting the evaporator further comprises: before controlling the refrigerant to circulate in the first direction and / or controlling the fan to rotate in the second direction, acquiring a first operating frequency of the compressor and a second temperature of the evaporator; when controlling the refrigerant to circulate in the first direction and controlling the fan to rotate in the second direction, controlling the compressor to operate at a preset frequency, wherein the preset frequency is inversely related to the second temperature of the evaporator.

8. The control method of the dehumidifier according to claim 7, wherein before controlling the refrigerant to circulate in the first direction and / or controlling the fan to rotate in the second direction, acquiring a third dry-bulb temperature of the operating environment; after controlling the compressor to operate at the preset frequency, the control method further comprises: obtaining a temperature of the evaporator to obtain a third temperature; determining whether the third temperature is greater than or equal to a second preset temperature, the second preset temperature being positively correlated with the third dry-bulb temperature; if yes, after a third preset time, controlling the dehumidifier to run in a dehumidifying mode, and the compressor runs at a first running frequency.

9. A dehumidifier, characterized by The dehumidifier comprises a control device, the control device comprises a memory and a processor, and the memory stores a control program. When the control program is executed by the processor, the control method of the dehumidifier according to any one of claims 1 to 8 is realized.

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