Heat pump clothes dryer and control method thereof

Abstract

The application provides a heat pump clothes dryer and a control method thereof. The heat pump clothes dryer comprises a containing cavity, a circulating air duct, a heating circulation assembly and a controller, and the circulating air duct and the containing cavity are communicated. The heating circulation assembly comprises a first compressor, a second compressor, an evaporator, a condenser, a condensation evaporator, a first throttling device and a second throttling device. The condensation evaporator comprises a condensation pipeline and an evaporation pipeline, and the condensation pipeline and the evaporation pipeline are in heat exchange. The first compressor, the condensation pipeline, the first throttling device and the evaporator are communicated to form a first heating circulation pipeline, the second compressor, the condenser, the second throttling device and the evaporation pipeline are communicated to form a second heating circulation pipeline, and the use temperature range of the refrigerant in the first heating circulation pipeline is lower than that in the second heating circulation pipeline. In this way, heat can be transmitted from the second heating circulation pipeline to the first heating circulation pipeline, so that the drying efficiency under low temperature condition is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of household appliances, and particularly relates to a heat pump clothes dryer and a control method thereof. BACKGROUND

[0002] With the gradual development of heat pump clothes dryer technology, in addition to the traditional way of drying clothes by airing, more and more people choose to dry clothes by using heat pump clothes dryer.

[0003] In the related art, the heat pump clothes dryer as an air source heat pump product includes a compressor, a condenser, an evaporator, a throttling device, a circulating air duct, and a drying barrel. The compressor, the condenser, the evaporator, and the throttling device form a refrigerant circulation loop. Heat is generated by using the energy conversion accompanied by the change of the form of the refrigerant. The main energy source is the heat in the air.

[0004] When winter comes, the air temperature is low, and the heat carried is less. In this case, the heat pump clothes dryer in the related art has a more severe heat attenuation at low temperature, a lower heating efficiency, and a poor drying effect of clothes. SUMMARY

[0005] To solve the above problems in the prior art, that is, to solve the problem of low heating efficiency of the heat pump clothes dryer due to low air temperature in the related art, the present application provides a heat pump clothes dryer, which comprises a containing cavity, a circulating air duct, a heating circulation assembly, and a controller. The circulating air duct and the containing cavity are in communication. The heating circulation assembly is used to heat the air in the circulating air duct, so that the circulating air duct blows dry air flow into the containing cavity.

[0006] The heating circulation assembly comprises a first compressor, a second compressor, an evaporator, a condenser, a condensing evaporator, a first throttling device, and a second throttling device. The condensing evaporator comprises a condensing pipeline and an evaporating pipeline, and the condensing pipeline and the evaporating pipeline have heat exchange therebetween. The first compressor, the condensing pipeline, the first throttling device, and the evaporator are sequentially connected and form a first heating circulation pipeline. The first heating circulation pipeline flows with first refrigerant. The second compressor, the condenser, the second throttling device, and the evaporating pipeline are sequentially connected and form a second heating circulation pipeline. The second heating circulation pipeline flows with second refrigerant. The use temperature range of the second refrigerant is higher than that of the first refrigerant.

[0007] The controller is used to control the working state of the first compressor and the second compressor, so that the first heating circulation pipeline heats the second heating circulation pipeline.

[0008] In an alternative embodiment of the heat pump clothes dryer, at least part of the condenser is arranged in the circulating air duct, and the condenser is configured to heat air in the circulating air duct.

[0009] In an alternative embodiment of the heat pump clothes dryer, the condenser-evaporator further comprises a first temperature detecting device arranged in the evaporating pipe and electrically connected to the controller, and the first temperature detecting device is configured to detect the temperature of the refrigerant in the evaporating pipe of the condenser-evaporator.

[0010] In an alternative embodiment of the heat pump clothes dryer, the heat pump clothes dryer further comprises a second temperature detecting device electrically connected to the controller, and the second temperature detecting device is configured to detect the ambient temperature of the heat pump clothes dryer.

[0011] In an alternative embodiment of the heat pump clothes dryer, the first throttling device is an expansion valve or a capillary tube, and the second throttling device is an expansion valve or a capillary tube.

[0012] Another embodiment of the present application provides a control method of a heat pump clothes dryer, and the control method comprises:

[0013] obtaining the ambient temperature of the heat pump clothes dryer;

[0014] if the ambient temperature is lower than a preset temperature threshold of the second refrigerant in the second heating circulation pipeline, controlling the first heating circulation pipeline to heat the second heating circulation pipeline, wherein the condensing part in the first heating circulation pipeline and the evaporating part in the second heating circulation pipeline have heat conduction, and the use temperature range of the first refrigerant in the first heating circulation pipeline is lower than the use temperature range of the second refrigerant in the second heating circulation pipeline;

[0015] when the evaporating end temperature of the second heating circulation pipeline is higher than or equal to the preset temperature threshold of the second refrigerant, controlling the second heating circulation pipeline to heat.

[0016] In an alternative embodiment of the control method, after the second heating circulation pipeline is controlled to heat, the control method further comprises detecting the temperature of the evaporating part in the second heating circulation pipeline.

[0017] when the temperature of the evaporating part is higher than a first temperature threshold, the first heating circulation pipeline stops heating;

[0018] when the temperature of the evaporating part is lower than a second temperature threshold, the first heating circulation pipeline starts heating, wherein the first temperature threshold is higher than the second temperature threshold.

[0019] In an optional embodiment of the above control method, after obtaining the ambient temperature of the heat pump clothes dryer, if the ambient temperature is higher than or equal to a preset temperature threshold of the second refrigerant in the second heating cycle pipeline, the second heating cycle pipeline is directly controlled to heat.

[0020] In an optional embodiment of the above control method, the second heating cycle pipeline uses a variable frequency compressor, and the circulating air duct is provided with a fan, and the control method further comprises:

[0021] obtaining a working frequency of the compressor in the second heating cycle pipeline;

[0022] adjusting a rotating speed of the fan in the circulating air duct according to the working frequency of the compressor, wherein the second heating cycle pipeline is used to heat air in the circulating air duct, and the fan is used to drive the air flow in the circulating air duct.

[0023] In an optional embodiment of the above control method, the adjusting of the rotating speed of the fan in the circulating air duct according to the working frequency of the compressor, the control method comprises:

[0024] in a process in which the working frequency of the compressor rises from zero to a preset working frequency, the fan is not started to rotate;

[0025] when the working frequency of the compressor is the preset working frequency, the fan is adjusted to a preset rotating speed;

[0026] when the working frequency of the compressor falls below the preset working frequency, the rotating speed of the fan is greater than the preset rotating speed.

[0027] The skilled in the art can understand that the heat pump clothes dryer and the control method thereof provided by the present application, wherein the heat pump clothes dryer comprises a containing cavity, a circulating air duct, a heating circulation assembly and a controller, the circulating air duct and the containing cavity are communicated. The heating circulation assembly comprises a first compressor, a second compressor, an evaporator, a condenser, a condensing evaporator, a first throttling device and a second throttling device; the condensing evaporator comprises a condensing pipeline and an evaporating pipeline, and the condensing pipeline and the evaporating pipeline have heat exchange therebetween. The first compressor, the condensing pipeline, the first throttling device and the evaporator are sequentially communicated and form a first heating circulation pipeline, the second compressor, the condenser, the second throttling device and the evaporating pipeline are sequentially communicated and form a second heating circulation pipeline, the second heating circulation pipeline flows with a second refrigerant, and the use temperature range of the second refrigerant is higher than that of the first refrigerant. The controller is used for controlling the working states of the first compressor and the second compressor, so that the first heating circulation pipeline heats the second heating circulation pipeline. The technical scheme of the present application utilizes the first heating circulation to deliver heat to the second heating circulation, so that the second heating circulation operates in the optimal working condition, and the drying efficiency of the heat pump clothes dryer under low temperature condition is improved. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by the skilled in the art without any creative labor.

[0029] Figure 1 The structural schematic diagram of the heat pump clothes dryer provided by an embodiment of the present application;

[0030] Figure 2 The structural schematic diagram of the heating circulation assembly provided by an embodiment of the present application;

[0031] Figure 3 The flow schematic diagram of the control method provided by an embodiment of the present application;

[0032] Figure 4 The flow schematic diagram of the control method provided by an embodiment of the present application;

[0033] Figure 5 The flow schematic diagram of the control method provided by an embodiment of the present application;

[0034] Figure 6 The flow schematic diagram of the control method provided by an embodiment of the present application;

[0035] Figure 7The schematic diagram of the curve of the power consumed by the compressor of the heat pump clothes dryer provided by an embodiment of the present application varying with the running time of the heat pump clothes dryer is shown in the figure.

[0036] Figure 8 The schematic diagram of the curve of the power consumed by the fan of the heat pump clothes dryer provided by an embodiment of the present application varying with the running time of the heat pump clothes dryer is shown in the figure.

[0037] Explanation of reference signs:

[0038] 1-heat pump clothes dryer;

[0039] 10-housing cavity;

[0040] 20-circulating air duct;

[0041] 30-heating cycle assembly;

[0042] 40-fan;

[0043] 50-first heating cycle pipeline;

[0044] 60-second heating cycle pipeline;

[0045] 31-first compressor;

[0046] 32-second compressor;

[0047] 33-evaporator;

[0048] 34-condenser;

[0049] 35-condensing evaporator;

[0050] 351-condensing pipeline;

[0051] 352-evaporating pipeline;

[0052] 36-first throttling device;

[0053] 37-second throttling device. DETAILED DESCRIPTION

[0054] First of all, those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application, and are not intended to limit the protection scope of the present application. Those skilled in the art can adjust them as needed in order to adapt to specific application occasions.

[0055] Secondly, it should be noted that in the description of the present application, the terms indicating the direction or positional relationship such as "inner", "outer" and the like are based on the direction or positional relationship shown in the drawings, which is only for the convenience of description, and does not indicate or imply that the device or member must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0056] In addition, it should be noted that, in the description of the present application, unless otherwise specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two components. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0057] With the gradual development of heat pump clothes drying machine technology, in addition to the traditional way of drying clothes by airing, more and more people choose to dry clothes with heat pump clothes drying.

[0058] In the related art, the clothes are dried by the heat pump clothes drying machine, which includes a compressor, a condenser, an evaporator, a throttling device, a circulating air duct and a drying barrel. The compressor, the condenser, the evaporator and the throttling device form a refrigerant circulation loop. The refrigerant is pressurized and heated by the compressor. The high-temperature and high-pressure refrigerant enters the condenser, and the condenser releases the heat of the refrigerant. The refrigerant enters the evaporator after being depressurized by the throttling device. The low-temperature condensate liquid exchanges heat with the outside air through the evaporator to achieve the effect of refrigeration. Then the refrigerant returns to the compressor to form a refrigerant circulation.

[0059] The condenser changes the dry cold air into dry hot air, and the dry hot air enters the drying barrel to dry the clothes. The dry hot air becomes humid cold air, and then the cold air enters the evaporator. The evaporator condenses the moisture in the cold air into water droplets. The dry cold air enters the condenser, and the cycle of air circulation is formed.

[0060] The above-mentioned heat pump clothes drying machine utilizes the morphological change of the refrigerant to convert energy, and the main energy source is the heat in the air. When the air temperature is low, the heat carried by the air is less. In this case, the heat pump clothes drying machine of the related art has a more severe heat attenuation at low temperature, and the heating efficiency is low, and the drying effect of the clothes is poor.

[0061] The technical scheme of the present application utilizes the first heating cycle to transport heat to the second heating cycle, so that the refrigerant of the second heating cycle operates at the optimal working condition, thereby improving the overall energy efficiency ratio and improving the drying efficiency of the heat pump clothes drying machine at low temperature.

[0062] The following describes an optional technical scheme of the heat pump clothes drying machine and the control method thereof according to an embodiment of the present application.

[0063] Embodiment one

[0064] Figure 1 The structure diagram of the heat pump clothes drying machine provided by an embodiment of the present application is shown in the figure. Figure 2A structure diagram of a heating cycle assembly is provided for an embodiment of the present application. Please refer to Figure 1 、 Figure 2 .

[0065] As shown in Figure 1 、 Figure 2 , the present embodiment provides a heat pump clothes dryer 1, which comprises a containing cavity 10, a circulating air duct 20, a heating cycle assembly 30, and a controller (not shown). The circulating air duct 20 and the containing cavity 10 are in communication, and the heating cycle assembly 30 is used to heat the air in the circulating air duct 20, so that the circulating air duct 20 blows the drying air flow into the containing cavity 10. The containing cavity 10 is a container for containing clothes to be dried, and is generally in the shape of a barrel. The containing cavity 10 is connected with a driving motor. The circulating air duct 20 is provided with a fan 40. The controller is electrically connected with the driving motor to control the rotation of the driving motor, and is electrically connected with the fan 40 to control the rotation of the fan 40.

[0066] The heating cycle assembly 30 comprises a first compressor 31, a second compressor 32, an evaporator 33, a condenser 34, a condensing evaporator 35, a first throttling device 36, and a second throttling device 37. The condensing evaporator 35 comprises a condensing pipeline 351 and an evaporating pipeline 352, and the condensing pipeline 351 and the evaporating pipeline 352 have heat exchange therebetween. The first compressor 31, the condensing pipeline 351, the first throttling device 36, and the evaporator 33 are in communication in sequence and form a first heating cycle pipeline 50, and the first heating cycle pipeline 50 flows with a first refrigerant. The second compressor 32, the condenser 34, the second throttling device 37, and the evaporating pipeline 352 are in communication in sequence and form a second heating cycle pipeline 60. The second heating cycle pipeline 60 flows with a second refrigerant, and the use temperature range of the second refrigerant is higher than that of the first refrigerant. The types of the first compressor 31 and the second compressor 32 can both be fixed-frequency compressors or both be variable-frequency compressors. Or the first compressor 31 is a fixed-frequency compressor and the second compressor 32 is a variable-frequency compressor, or vice versa.

[0067] Specifically, in the embodiment, the heating cycle assembly 30 includes two refrigerant cycles, i.e., a first heating cycle pipeline 50 and a second heating cycle pipeline 60. The first heating cycle pipeline 50 and the second heating cycle pipeline 60 are coupled through the condensing evaporator 35. In the first heating cycle pipeline 50, the discharge port of the first compressor 31 is in communication with the inlet of the condensing pipeline 351 of the condensing evaporator 35, the outlet of the condensing pipeline 351 of the condensing evaporator 35 is in communication with the inlet of the first throttling device 36, the outlet of the first throttling device 36 is in communication with the inlet of the evaporator 33, and the outlet of the evaporator 33 is in communication with the suction port of the first compressor 31. The first refrigerant in the first heating cycle pipeline 50 is sequentially flowed through the first compressor 31, the condensing evaporator 35, the first throttling device 36, and the evaporator 33, and finally backflows to the first compressor 31. In the cycle, the first refrigerant in the condensing pipeline 351 of the condensing evaporator 35 changes from a gaseous state to a liquid state and releases heat, and the evaporator 33 causes the first refrigerant to boil and vaporize and absorbs heat. The first throttling device 36 and the second throttling device 37 can be an expansion valve or a capillary tube.

[0068] In the second heating cycle pipeline 60, the discharge port of the second compressor 32 is in communication with the inlet of the condenser 34, the outlet of the condenser 34 is in communication with the inlet of the second throttling device 37, the outlet of the second throttling device 37 is in communication with the inlet of the evaporating pipeline 352 of the condensing evaporator 35, the outlet of the evaporating pipeline 352 of the condensing evaporator 35 is in communication with the suction port of the second compressor 32, and the second refrigerant in the second heating cycle pipeline 60 is sequentially flowed through the condenser 34, the second throttling device 37, and the condensing evaporator 35, and finally backflows to the second compressor 32. In the cycle, the second refrigerant in the condensing evaporator 35 boils and vaporizes and absorbs heat, and the condenser 34 causes the second refrigerant to change from a gaseous state to a liquid state and releases heat.

[0069] The use temperature range of the second refrigerant is greater than that of the first refrigerant. Specifically, the first refrigerant is a low-temperature refrigerant, and the second refrigerant is a medium-temperature refrigerant. The first refrigerant can efficiently heat the first heating cycle pipeline 50 in a low-temperature environment, and the heat generated by the first heating cycle pipeline 50 is transmitted to the second heating cycle pipeline 60, so that the second refrigerant in the second heating cycle pipeline 60 can work in good working conditions, thereby improving the heating efficiency of the second heating cycle pipeline 60, improving the overall energy efficiency ratio, and improving the drying efficiency of the heat pump clothes dryer 1 in a low-temperature environment. The controller is configured to control the working states of the first compressor 31 and the second compressor 32 to heat the second heating cycle pipeline 60 by the first heating cycle pipeline 50.

[0070] In an alternative embodiment, at least part of the condenser 34 is arranged in the circulating air duct 20, and the condenser 34 is used to heat the air in the circulating air duct 20. The containing cavity 10 is used to contain clothes to be dried, the condenser 34 of the second heating cycle pipeline 60 is arranged in the circulating air duct 20, the condenser 34 of the second heating cycle pipeline 60 releases heat, the circulating air in the circulating air duct 20 is heated by the condenser 34 to become dry hot air, and the fan 40 sends the dry hot air into the containing cavity 10 to achieve drying of the clothes.

[0071] In an alternative embodiment, the condensing evaporator 35 further comprises a first temperature detection device (not shown), which is arranged in the evaporating pipeline 352 and is electrically connected to the controller, and is used to detect the temperature of the refrigerant in the evaporating pipeline 352 of the condensing evaporator 35. In this way, the temperature state of the second refrigerant about to enter the second compressor 32 in the second heating cycle pipeline 60 can be conveniently monitored.

[0072] In an alternative embodiment, the heat pump clothes dryer 1 further comprises a second temperature detection device (not shown), which is electrically connected to the controller and is used to detect the ambient temperature of the heat pump clothes dryer 1. The ambient temperature is the air temperature where the heat pump clothes dryer 1 is located, i.e. the temperature of the air in the circulating air duct 20 in the heat pump clothes dryer 1. At the same time, the second heating cycle pipeline 60 is further provided with a third temperature detection device (not shown), which is arranged in the condenser 34 and is used to detect the temperature of the second refrigerant in the condenser 34.

[0073] In an alternative embodiment, the first throttling device 36 and the second throttling device 37 are expansion valves. The function of the expansion valve is to make the medium-temperature high-pressure refrigerant throttled into low-temperature low-pressure wet steam.

[0074] Based on the same inventive concept, the embodiments of the present application also provide a control method corresponding to the heat pump clothes dryer in the above-mentioned embodiments.

[0075] Embodiment Two

[0076] Figure 3 A flowchart of a control method of a heat pump clothes dryer according to an embodiment of the present application is shown in Figures 1-3 .

[0077] As Figure 3 shown, in an alternative embodiment, the control method comprises:

[0078] S101, obtaining the ambient temperature of the heat pump clothes dryer.

[0079] That is, before the heat pump clothes dryer performs the drying operation, the controller acquires the ambient temperature in which the heat pump clothes dryer is located, that is, the temperature of the air in the circulating air duct.

[0080] S102, if the ambient temperature is lower than the preset temperature threshold of the second refrigerant in the second heating cycle pipeline, the first heating cycle pipeline is controlled to heat the second heating cycle pipeline, wherein the condensing part in the first heating cycle pipeline and the evaporating part in the second heating cycle pipeline have heat conduction, and the use temperature range of the first refrigerant in the first heating cycle pipeline is lower than the use temperature range of the second refrigerant in the second heating cycle pipeline.

[0081] When the ambient temperature is acquired, the ambient temperature is compared with the preset temperature threshold of the second refrigerant, which is a preset temperature value. The preset temperature threshold of the second refrigerant can be set according to the type of refrigerant used. Then there are three cases: the ambient temperature is higher than the preset temperature threshold of the second refrigerant, the ambient temperature is the same as the preset temperature threshold of the second refrigerant, and the ambient temperature is lower than the preset temperature threshold of the second refrigerant. The first heating cycle pipeline can conduct heat to the second heating cycle pipeline. The preset temperature threshold of the second refrigerant is used to determine whether the first heating cycle pipeline needs to be started. The preset temperature threshold of the second refrigerant can be set according to the actual working condition. At the same time, in order to avoid the energy consumption caused by the simultaneous start of the two heating cycle pipelines, the first heating cycle pipeline is started first in the initial stage, that is, when the temperature of the clothes load is relatively low and almost no dehumidification is required.

[0082] Specifically, in the case where the ambient temperature is lower than the preset temperature threshold of the second refrigerant in the second heating cycle pipeline, the controller controls the first heating cycle pipeline to heat the evaporating end of the second heating cycle pipeline. The evaporating end is the part of the second heating cycle pipeline used for evaporating the refrigerant, which can be the evaporating pipe part of the condenser evaporator. The condensing part in the first heating cycle pipeline can conduct heat to the evaporating part in the second heating cycle pipeline. The use temperature range of the first refrigerant in the first heating cycle pipeline is lower than the use temperature range of the second refrigerant in the second heating cycle pipeline. In the case of low temperature, the first heating cycle pipeline has higher heating efficiency.

[0083] S103, when the temperature of the evaporating end of the second heating cycle pipeline is higher than or equal to the preset temperature threshold of the second refrigerant, the second heating cycle pipeline is controlled to be heated.

[0084] That is, when the temperature of the evaporating end of the second heating cycle pipeline reaches the use temperature range of the second refrigerant, the conditions for efficient heating of the second heating cycle pipeline are met, and the second heating cycle pipeline is controlled to be heated to improve the heating efficiency.

[0085] Figure 4 The flowchart of another control method of the heat pump clothes dryer is provided for an embodiment of the present application. In an alternative embodiment, as shown in Figure 4 After the second heating cycle pipeline is controlled to heat, the control method further comprises:

[0086] S201, detecting the temperature of the evaporation part in the second heating cycle pipeline.

[0087] The temperature of the evaporation part in the second heating cycle pipeline refers to the temperature of the evaporation end in the second heating cycle pipeline, specifically, the temperature of the second refrigerant in the evaporation pipeline in the condenser.

[0088] S202, when the temperature of the evaporation part is higher than the first temperature threshold, the first heating cycle pipeline stops heating.

[0089] That is, in order to prevent the second compressor of the second heating cycle pipeline from working at too high a temperature and triggering overheat protection, the first temperature threshold is preset, which can be determined according to the model of the second compressor and the model of the second refrigerant. When the temperature of the refrigerant reaches the first temperature threshold, the first heating cycle pipeline is closed to stop delivering heat to the second heating cycle pipeline.

[0090] S203, when the temperature of the evaporation part is lower than the second temperature threshold, the first heating cycle pipeline starts heating, wherein the first temperature threshold is higher than the second temperature threshold.

[0091] That is, the first temperature threshold can be determined according to the model of the second compressor and the model of the second refrigerant. In order to keep the first heating cycle pipeline working efficiently, when the temperature of the evaporation part is lower than the second temperature threshold, in order to ensure that the second heating cycle pipeline can heat efficiently and obtain good drying effect, the first heating cycle pipeline needs to work to provide heat for the second heating cycle pipeline.

[0092] In an alternative embodiment, after the ambient temperature of the heat pump clothes dryer is obtained, the control method further comprises:

[0093] If the ambient temperature is higher than or equal to the preset temperature threshold of the second refrigerant in the second heating cycle pipeline, the second heating cycle pipeline is directly controlled to heat.

[0094] That is, the ambient temperature is higher than the preset working temperature of the second refrigerant, and the second refrigerant can work at a good temperature, and the second heating cycle pipeline can heat efficiently under this working condition. In order to save energy, the first heating cycle pipeline does not need to be started.

[0095] Figure 5A flowchart of a fan control method in a heat pump clothes dryer according to an embodiment of the present application is shown in FIG. 1. In an alternative embodiment, as shown in FIG. 2, a variable frequency compressor is used in the second heating cycle pipeline, and a fan is arranged in the circulating air duct. The control method further comprises the following steps: Figures 5-8

[0096] S301, obtaining the working frequency of the compressor in the second heating cycle pipeline.

[0097] Specifically, the working frequency of the compressor refers to the main parameter of the compressor operation. In this embodiment, the rotational speed of the compressor is selected as its working frequency.

[0098] S302, adjusting the rotational speed of the fan in the circulating air duct according to the working frequency of the compressor, wherein the second heating cycle pipeline is used to heat the air in the circulating air duct, and the fan is used to drive the air flow in the circulating air duct.

[0099] The controller obtains the working frequency of the compressor in the second heating cycle pipeline, and selects the appropriate timing to start the fan and adjust the working state of the fan according to the heating efficiency of the second heating cycle pipeline, thereby improving the overall energy efficiency.

[0100] Further, Figure 6 A flowchart of another fan control method in a heat pump clothes dryer according to an embodiment of the present application is shown in FIG. 3. Figure 7 A curve diagram showing the change of the power consumed by the compressor of a heat pump clothes dryer with the running time of the heat pump clothes dryer according to an embodiment of the present application is shown in FIG. 4. Figure 8 A curve diagram showing the change of the power consumed by the fan of a heat pump clothes dryer with the running time of the heat pump clothes dryer according to an embodiment of the present application is shown in FIG. 5. Figures 5-8

[0101] S401, during the process of increasing the working frequency of the compressor from zero to a preset working frequency, the fan is not started to rotate.

[0102] When the heat pump clothes dryer is just started, the working frequency of the compressor starts to increase from zero. When the running time of the working frequency of the compressor reaches N1, the compressor reaches the preset rotational speed, and the heating efficiency is relatively high. The rotational speed of the fan at the running time S1 is 0, i.e. the fan does not consume energy during this process. At this time, the compressor has just started to heat efficiently, and the heat generated by the second heating cycle pipeline is not enough to effectively dry the clothes, so the fan does not rotate.

[0103] S402, when the working frequency of the compressor is the preset working frequency, adjusting the fan to a preset rotational speed.

[0104] ​​When the working frequency of the compressor is in the interval of N1-N2, the power consumed by the compressor in this interval is constant, and the compressor operates at a preset working frequency. In this interval, the second heating circulation pipeline can efficiently and stably heat as the compressor operates, and at this time, the fan operates in the interval of S1-S2, the power consumed by the fan is constant, and the fan operates at a preset speed. When the working frequency of the compressor operates at a preset frequency, the fan adjusts its speed to efficiently transfer heat.

[0105] S403, when the working frequency of the compressor decreases to be lower than the preset working frequency, the speed of the fan is greater than the preset speed.

[0106] When the working frequency of the compressor is in the interval of N2-N3, after the compressor operates in the interval of N1-N2, the clothes in the containing cavity have become dry, the heat load of the system becomes small, and the power consumed by the compressor gradually decreases. Correspondingly, although the surface of the clothes is dry, the power consumed by the compressor also decreases, but at this time, there is still some moisture in the clothes, and when the fan operates in the interval of S2-S3, in order to quickly dry the moisture in the clothes, the speed of the fan is increased, that is, the power consumption of the fan is increased, the process of transferring the moisture in the clothes to the surface of the clothes is accelerated, and the drying efficiency is improved.

[0107] As can be known from the above description, the heat pump clothes dryer provided in the embodiment can efficiently heat the heat pump clothes dryer in a low-temperature environment, thereby improving the drying efficiency in a low-temperature condition.

[0108] Those skilled in the art should understand that the terms "first" and "second" are used for description purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0109] It should be noted that in the description of the present application, the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0110] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A heat pump clothes dryer characterized by comprising: The heat pump clothes dryer comprises a containing cavity, a circulating air duct, a heating circulation assembly and a controller, the circulating air duct and the containing cavity are communicated, and the heating circulation assembly is used for heating air in the circulating air duct to make the circulating air duct blow dry air into the containing cavity. The heating circulation assembly comprises a first compressor, a second compressor, an evaporator, a condenser, a condensation evaporator, a first throttling device and a second throttling device; the condensation evaporator comprises a condensation pipeline and an evaporation pipeline, and the condensation pipeline and the evaporation pipeline have heat exchange; the first compressor, the condensation pipeline, the first throttling device and the evaporator are sequentially communicated and form a first heating circulation pipeline, and a first refrigerant flows in the first heating circulation pipeline; the second compressor, the condenser, the second throttling device and the evaporation pipeline are sequentially communicated and form a second heating circulation pipeline, and a second refrigerant flows in the second heating circulation pipeline; the use temperature range of the second refrigerant is higher than that of the first refrigerant. The controller is used for controlling the working states of the first compressor and the second compressor to heat the first heating circulation pipeline for the second heating circulation pipeline. At least part of the structure of the condenser is arranged in the circulating air duct, and the condenser is used for heating air in the circulating air duct.

2. The heat pump clothes dryer of claim 1, wherein The condensation evaporator further comprises a first temperature detection device arranged in the evaporation pipeline and electrically connected with the controller, and the first temperature detection device is used for detecting the refrigerant temperature of the evaporation pipeline in the condensation evaporator.

3. The heat pump clothes dryer of claim 1, wherein The heat pump clothes dryer further comprises a second temperature detection device electrically connected with the controller, and the second temperature detection device is used for detecting the ambient temperature of the heat pump clothes dryer.

4. The heat pump clothes dryer of claim 1, wherein The first throttling device is an expansion valve or a capillary tube, and the second throttling device is an expansion valve or a capillary tube.

5. A control method suitable for a heat pump clothes drying machine as claimed in any one of the claims 1-4, characterized in that, The control method comprises: obtaining the ambient temperature of the heat pump clothes dryer; if the ambient temperature is lower than a preset temperature threshold of the second refrigerant in the second heating circulation pipeline, controlling the first heating circulation pipeline to heat the second heating circulation pipeline, wherein the condensation part in the first heating circulation pipeline and the evaporation part in the second heating circulation pipeline have heat conduction, and the use temperature range of the first refrigerant in the first heating circulation pipeline is lower than that of the second refrigerant in the second heating circulation pipeline; when the evaporation end temperature of the second heating circulation pipeline is higher than or equal to the preset temperature threshold of the second refrigerant, controlling the second heating circulation pipeline to be heated.

6. The control method according to claim 5, characterized by After the second heating circulation pipeline is controlled to be heated, the control method further comprises detecting the evaporation part temperature in the second heating circulation pipeline; when the evaporation part temperature is higher than a first temperature threshold, the first heating circulation pipeline stops heating; when the evaporation part temperature is lower than a second temperature threshold, the first heating circulation pipeline starts heating, wherein the first temperature threshold is higher than the second temperature threshold.

7. The control method according to claim 5, characterized by, After the environment temperature where the heat pump clothes dryer is located is acquired, if the environment temperature is higher than or equal to a preset temperature threshold of a second refrigerant in a second heating circulation pipeline, the second heating circulation pipeline is directly controlled to heat.

8. The control method according to any one of claims 5 to 7, characterized by, The second heating circulation pipeline adopts a variable frequency compressor, and a fan is arranged in the circulating air duct, and the control method further comprises: acquiring a working frequency of a compressor in the second heating circulation pipeline; adjusting a rotating speed of the fan in the circulating air duct according to the working frequency of the compressor, wherein the second heating circulation pipeline is used to heat air in the circulating air duct, and the fan is used to drive the air in the circulating air duct to flow.

9. The control method according to claim 8, characterized by, The control method comprises: in a process that the working frequency of the compressor rises from zero to a preset working frequency, the fan is not started to rotate; when the working frequency of the compressor is the preset working frequency, the fan is adjusted to a preset rotating speed; when the working frequency of the compressor falls below the preset working frequency, the rotating speed of the fan is greater than the preset rotating speed.

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