CN114182474B

CN114182474B - Washing machine with heat pump drying function and drying control method

Info

Publication number: CN114182474B
Application number: CN202111444272.7A
Authority: CN
Inventors: 林帆; 覃显钧; 赖毅俊; 卢诗雅
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2022-08-26
Anticipated expiration: 2041-11-30
Also published as: CN114182474A

Abstract

The invention belongs to the technical field of drying, and particularly relates to a washing machine with a heat pump drying function and a drying control method, wherein the washing machine comprises an outer cylinder and an inner cylinder which is rotatably arranged in the outer cylinder, and a heating device is arranged at the bottom of the outer cylinder; the washing machine also comprises a drying system and a control system, wherein the drying system comprises a drying fan and a heat pump module, when the washing machine executes a drying program, the control system controls the drying fan to start, and when a set condition of entering a preheating stage is reached, the control system controls the water level of the outer barrel to be at a heating water level; when the water level of the outer barrel reaches the heating water level, the control system controls the heating device to start heating; when the set condition for finishing the preheating stage is reached, the control system controls the heating device to stop heating and controls the heat pump module to start to enter the drying stage. The washing machine and the drying control method can improve the heat pump drying efficiency in a low-temperature environment and reduce the drying cost.

Description

Washing machine with heat pump drying function and drying control method

Technical Field

The invention belongs to the technical field of drying, and particularly relates to a washing machine with a heat pump drying function and a drying control method.

Background

Compared with electric heating drying, the heat pump drying has the advantages of low working temperature and less damage to clothes. However, in a low temperature environment, the heat pump has low working efficiency, and the system is heated by increasing the electric auxiliary heat to improve the drying efficiency, however, the increase of the electric auxiliary heat element means the increase of the cost.

The present invention has been made in view of this situation.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defects of the prior art and provide a washing machine with a heat pump drying function and a drying control method.

In order to solve the technical problem, the invention provides a washing machine with a heat pump drying function, which comprises an outer cylinder and an inner cylinder which is rotatably arranged in the outer cylinder, wherein a heating device is arranged at the bottom of the outer cylinder;

the washing machine further comprises a drying system and a control system, wherein the drying system comprises a drying fan, a compressor, an evaporator and a condenser, when the washing machine executes a drying program, the control system controls to obtain the ambient temperature, and when the ambient temperature is lower than a first set temperature, the control system controls the washing machine to enter a preheating stage; in the preheating stage, the control system controls the water level of the outer barrel to be at a heating water level and controls the heating device to start heating; the control system also obtains the water temperature of the outer cylinder and the temperature of the air inlet of the evaporator, and when the water temperature of the outer cylinder and the temperature of the air inlet of the evaporator reach the set conditions for starting the heat pump system, the control system controls the heat pump system to start; when the set condition for finishing the preheating stage is reached, the control system controls the heating device to stop heating and controls the washing machine to enter a drying stage.

Further optionally, the washing machine further comprises a water inlet valve, the drying system comprises a condensed water channel, one end of the condensed water channel is communicated with the water inlet valve, and the other end of the condensed water channel extends along the wall of the outer barrel to be communicated with the bottom of the outer barrel;

in the preheating stage, when the water level of the outer barrel is lower than a safe water level, the control system also controls a water inlet valve to feed water, water flowing out of the water inlet valve enters the bottom of the outer barrel through the condensed water channel, and when the water level of the outer barrel reaches a heating water level, the control system controls the water inlet valve to stop feeding water.

The invention also provides a drying control method of the washing machine, the washing machine comprises a drying program, and the drying program comprises a preheating stage and a drying stage; the control method comprises the following steps:

the method comprises the steps that when the washing machine executes a drying program, the ambient temperature is obtained;

when the ambient temperature is lower than a first set temperature, controlling the washing machine to enter a preheating stage;

in the preheating stage, controlling the water level of the outer barrel to be at a heating water level, and controlling the heating device to start heating;

acquiring the water temperature of the outer cylinder and the temperature of an air inlet of an evaporator, and controlling the heat pump system to start when the water temperature of the outer cylinder and the temperature of the air inlet of the evaporator respectively reach set conditions for starting the heat pump system;

and when the set condition for finishing the preheating stage is reached, controlling the heating device to stop heating, and controlling the washing machine to enter a drying stage.

Further optionally, the acquiring the water temperature of the outer cylinder and the air inlet temperature of the evaporator, and controlling the heat pump system to start when the water temperature of the outer cylinder and the air inlet temperature of the evaporator respectively reach the set conditions for starting the heat pump system, includes

Respectively acquiring the water temperature of the outer barrel and the air inlet temperature of the evaporator;

when the water temperature of the outer barrel reaches a second set temperature, controlling the fan to start;

and when the temperature of the air inlet of the evaporator reaches a third set temperature, controlling the compressor to start.

Further optionally, the set condition for reaching the end of the preheating phase comprises

And acquiring the temperature of the air inlet of the evaporator, and reaching the set condition for ending the preheating stage when the temperature of the air inlet of the evaporator rises to a fourth set temperature.

Further optionally, the controlling the water level of the outer tub at a heating water level comprises

After washing is finished, the outer barrel is controlled to drain water to a heating water level, and then the water drainage is stopped;

or after the washing machine enters the drying program, controlling the water inlet valve to feed water to the heating water level and stopping feeding water.

Further optionally, the washing machine controls the water inlet valve to feed water to the heating water level after entering the drying program and stops feeding water, including

And controlling the water inlet valve to feed water according to a set water inlet time sequence, and stopping feeding water when the water is fed to a heating water level.

Further optionally, the inner barrel is controlled to rotate at the first rotation speed during the water inlet process by controlling the water inlet valve to feed water according to the set water inlet time sequence.

Further optionally, the control method further comprises

In the preheating stage, the inner barrel is also controlled to rotate forward and backward alternately at a second rotating speed under a certain rotation-stop ratio, and the first rotating speed is greater than the second rotating speed.

Further optionally, the control method further includes: during the preheating stage, the water temperature is maintained within the set temperature range by controlling the heating device to start and stop heating.

Further optionally, the control method further comprises

In the preheating stage, whether the water level at the bottom of the outer barrel is lower than a safe water level or not is monitored, and if the water level is lower than the safe water level, the heating device is controlled to stop heating; the safe water level is less than the heating water level and less than or equal to the highest water level;

judging whether the end condition of the preheating stage is reached, and if the end condition of the preheating stage is reached, ending the preheating stage; and if the condition does not reach the end condition of the preheating stage, controlling the water inlet valve to supplement water to a heating water level, and controlling the heating device to start heating again.

After adopting the technical scheme, compared with the prior art, the invention has the following beneficial effects:

the embodiment adds the heating device at the bottom of the outer drum to heat the water to improve the internal temperature of the washing machine on the basis of the washing machine with the existing basic structure, thereby improving the drying efficiency of the heat pump of the washing machine and reducing the cost of additional elements.

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention, are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without limiting the invention to the right. It is obvious that the drawings in the following description are only some embodiments, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:

fig. 1 is a structural view showing a washing machine according to a first embodiment of the present invention;

fig. 2 shows an exploded view of a two-component case according to a second embodiment of the invention;

FIG. 3 is a schematic view of the two-box body of the second embodiment of the present invention, showing the air inlet side of the two-box body;

FIG. 4 is a schematic top view of a second embodiment of the present invention;

FIG. 5 is a schematic view of the lower surface of the two covers of the second embodiment of the present invention;

FIG. 6 shows an exploded view of a two-piece enclosure cover and spray cover of example two of the present invention;

FIG. 7 is an exploded view showing the connection of two cartridges of a washing machine according to a second embodiment of the present invention with an outer tub of a heat pump washing machine;

FIG. 8 is a control flow chart of a third embodiment of the present invention;

fig. 9 shows a control flow diagram of an embodiment of the present invention.

It should be noted that the drawings and the description are not intended to limit the scope of the inventive concept in any way, but to illustrate it by a person skilled in the art with reference to specific embodiments.

Detailed Description

In the description of the present invention, it should be noted that the terms "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," "contacting," and "communicating" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example one

In order to solve the problem that the existing washing machine with a heat pump drying function has low drying efficiency in a lower external environment, the embodiment provides a washing machine with a heat pump drying function, the washing machine of the embodiment can be a pulsator washing machine or a drum washing machine, as shown in fig. 1, the washing machine of the embodiment comprises an outer drum 23 and an inner drum 3 rotatably arranged in the outer drum 23, and a heating device 11 is arranged at the bottom of the outer drum 23; the washing machine also comprises a drying system and a control system, wherein the drying system comprises a drying fan, a compressor and a heat pump module 4, the heat pump module 4 comprises an evaporator and a condenser, the control system controls and obtains the ambient temperature when the washing machine executes a drying program, and the control system controls the washing machine to enter a preheating stage when the ambient temperature is lower than a first set temperature; in the preheating stage, the control system controls the water level of the outer cylinder 23 to be at a heating water level, and controls the heating device 11 to start heating; the control system also obtains the water temperature of the outer cylinder 23 and the temperature of the air inlet of the evaporator, and when the water temperature of the outer cylinder 23 and the temperature of the air inlet of the evaporator reach the set conditions for starting the heat pump system, the control system controls the heat pump system to start; when the set condition for ending the preheating stage is reached, the control system controls the heating device 11 to stop heating, and controls the washing machine to enter the drying stage.

This embodiment improves a section of thick bamboo internal environment temperature through the water of heating inner tube 3 bottom under the lower stoving environment of temperature to improve heat pump drying efficiency. In the present embodiment, the heating device 11 is additionally arranged at the bottom of the outer tub 23, and the heating device 11 is located in the space between the inner tub 3 and the outer tub 23 for heating the washing water. The heating device 11 is provided with a water temperature sensing detecting element for detecting the temperature of the heating water. The heating device 11 can rapidly heat the water at the bottom of the outer cylinder 23 in a short time, and the ambient temperature in the cylinder is raised by the heat generated by heating the water.

The outer tub 23 of this embodiment is used for storing washing water, and has a drain mechanism at the bottom thereof for draining the washed water, and the drain mechanism is a drain valve or a drain pump for draining the waste water in the outer tub 23 to the outside. The inner cylinder 3 of this embodiment is installed inside the outer cylinder 23, and has a plurality of through holes on its wall, which are in spatial communication with the outer cylinder 23. In the washing or rinsing procedure, water enters the inner drum 3 through the through holes to wash or rinse the clothes; in the dehydration process, the inner cylinder 3 drives the clothes to rotate at a high speed to generate centrifugal force to squeeze out the moisture of the clothes, and the moisture flows into the outer cylinder 23 through the communication holes. The water heating device 11 is arranged at the bottom of the inner barrel 3 and is positioned in the space between the inner barrel 3 and the outer barrel 23 for heating the washing water, a water temperature sensing detection element is arranged in the heating device or a separate temperature detection device is arranged in the washing machine for detecting the water temperature of the outer barrel. The heating means 11 may alternatively be resistive heating.

As shown in fig. 1, in order to prevent the heating device 11 from being burned dry, it is necessary to ensure that the heating device 11 is located below the liquid level and a sufficient water level is left during heating. When the water level drops below the safe water level L, the water heating is stopped immediately and the water is supplemented in time to prevent dry burning. According to the electrical safety regulations, the heating device 11 is sufficiently distanced from the bottom of the inner drum 3. Therefore, the water heating is performed within a range in which the heating water level R is set between the bottom of the inner tub 3 and the safe water level, the maximum water level below the bottom of the inner tub 3 is set as the upper limit of the heating water level H, and the safe water level L above the water heating device 11 is set as the lower limit of the heating water level, so that the steam can be generated while preventing the laundry in the inner tub 3 from contacting the water in the bottom. The safety water level L and the maximum water level H in this embodiment have a fluctuation range of a certain margin, instead of a fixed water level value. Optionally, the tangential distance from the highest water level H to the bottom of the inner barrel 3 is 0-5 mm, preferably 5 mm; the distance from the safe water level L to the upper end face of the heating device 11 is 5-10 mm, preferably 10 mm.

The drying system of this embodiment includes drying fan, wind channel and heat pump module 4, drying fan carries the air in the inner tube 3 to heat pump module 4 through the stoving wind channel after the condensation heating forms the dry hot air, send back again to the inner tube 3 through the stoving wind channel and thereby form the circulation, heat pump module 4 of this embodiment includes the compressor, throttling arrangement, condenser and evaporimeter, make the refrigerant gasify the heat absorption in the evaporimeter and condense exothermic in the condenser through compressor and throttling arrangement, regard as the cold source with the evaporimeter, the condenser is as the heat source.

Further optionally, the washing machine further comprises a water inlet valve assembly 71, wherein the water inlet valve assembly comprises one or more water inlet valves 713, when there are multiple water inlet valves 713, different water inlet valves are communicated with different pipelines, for example, some water inlet valves are used for inlet water for washing clothes, some water inlet valves are used for inlet water for performing spray washing on a filter screen in the heat pump module 4, some water inlet valves are used for inlet water for cooling a condenser in the heat pump module 4, and some water inlet valves are used for inlet water for generating steam by a heating device. The inlet valve drying system comprises a condensed water channel 44, one end of the condensed water channel 44 is communicated with one of the inlet valves 713, and the other end of the condensed water channel 44 extends along the wall of the outer cylinder 23 to be communicated with the bottom of the outer cylinder 23; in the preheating stage, when the water level of the outer cylinder 23 is lower than the safe water level, the control system also controls the water inlet valve to feed water, the water flowing out of the water inlet valve enters the bottom of the outer cylinder 23 through the condensed water channel 44, and when the water level of the outer cylinder 23 reaches the heating water level, the control system controls the water inlet valve to stop feeding water.

The condensed water passage 44 in this embodiment is configured to receive and collect condensed water generated from the evaporator for guiding the condensed water generated during the drying process between the inner tub 3 and the outer tub 23. The hot air passing through the condenser under the action of the drying fan is sent to the inner barrel 3, the moisture of the clothes is evaporated when the hot air passes through the clothes, the air with the moisture is sent back to the evaporator, the moisture in the air is absorbed by the evaporator and condensed into water when meeting the condensation, the generated condensed water flows to the bottom of the barrel through a condensation channel, and the air dried outside the exhaust system is sent to the inner barrel 3 through a heat source to form circulation. In the embodiment, the condensed water channel 44 is connected with the water inlet valve, water in the flow path of the water inlet valve flows to the bottom of the outer cylinder 23 along the wall surface of the outer cylinder 23 through the condensed water channel 44, and when the environment in the cylinder is preheated, water entering the outer cylinder 23 from the water inlet valve directly enters the outer cylinder 23 from the condensed water channel 44 arranged in the outer cylinder 23 without passing through the inner cylinder 3, so that the drying time is prevented from being prolonged due to the fact that the humidity of clothes is increased after water enters the inner cylinder 3.

Example two

The present embodiment is an improvement of the heat pump module based on embodiment 1. The heat pump module of the present embodiment includes an evaporator and a condenser, which are integrally disposed in a two-tank, as shown in fig. 2 to 6, the two-tank includes: a two-box 443 having an accommodating space for accommodating the condenser 442 and the evaporator 441 of the heat pump washing machine, wherein an opening is formed above the two-box 443, two sides of the two-box 443 are provided with a two-box inlet a and a two-box outlet b, the two-box inlet a is used for allowing the hot and humid air discharged from the outer tub 23 of the heat pump washing machine during drying of the heat pump washing machine to enter one side of the evaporator 441 for condensation drying, and the two-box outlet b is used for discharging the hot air heated by the condenser 442 after drying of the evaporator 441 into the outer tub 23; the two-box cover 444 is covered with the opening of the two-box body 443, the two-box cover 444 is provided with a spraying device, and a spraying port c of the spraying device is positioned on the lower surface of the two-box cover 444 and faces one side of the two-box air outlet b.

In this embodiment, the two covers 444 may be fixedly connected to the two covers 444 by screws.

In the embodiment, the two box bodies are arranged, so that the condenser and the evaporator can be placed together, when the heat pump washing machine dries, the length of an air channel is reduced, the heat loss is reduced, the condenser and the evaporator work more efficiently, and the problem that the condenser and the evaporator adopt a dispersed arrangement low-efficiency work to occupy a larger space structure to cause a larger volume of the heat pump washing machine is solved. Meanwhile, the spraying device is arranged to spray water to the windward side of the evaporator, so that flocks and peculiar smell of clothes attached to the evaporator in the drying process can be removed, and condensation of the hot and humid air on the surface of the evaporator is accelerated.

In order to further improve the effect of removing the flocks and condensing, it is preferable that the spraying port c is configured such that water sprayed therefrom can be sprayed to the top of the windward side of the evaporator 441 or a position close to the top of the windward side of the evaporator 441, such that water flows into the bottom from the top of the evaporator 441 to discharge the flocks, and at the same time, the contact surface between the sprayed water and the hot and humid air is increased, the effect of condensing and dehumidifying the hot and humid air is improved, and the spraying device can spray more efficiently. Preferably, the spraying port c is close to the top of the evaporator 441 and is arranged opposite to the windward side of the evaporator 441. Optionally, the water spraying direction of the spraying port c is parallel to the air inlet direction of the air inlet a of the two tank boxes, so that the thickness (height direction) of the spraying device on the two tank box cover 444 can be reduced, and the overall height of the two tank boxes can be further reduced.

In this embodiment, the bottom of the two-device box 443 is provided with a water outlet for discharging water sprayed from the spraying device.

Optionally, an avoiding groove is formed on the lower surface of the two container covers 444, an avoiding protrusion is formed at the position of the avoiding groove on the upper surface of the two container covers 444, and the avoiding protrusion and the upper surface of the two container covers 444 are in smooth transition to form a smooth surface, which is beneficial to reducing the overall height of the two container covers.

In an embodiment of this embodiment, the spraying device includes a water inlet joint 445 and a spraying box communicated with the water inlet joint 445, the two box covers 444 are provided with accommodating openings, the spraying box is embedded in the accommodating openings and located on the windward side of the evaporator 441, the spraying box is connected with the two box covers 444 in a sealing manner, and the side wall of the spraying box facing the windward side of the evaporator 441 is provided with a plurality of spraying openings c. The spraying box is embedded into the accommodating port and is positioned on the windward side of the evaporator 441, so that the distance from the upper surface of the two box covers 444 to the lower surface of the spraying box can be reduced, the overall height of the two boxes is further reduced, the arrangement of the heat pump type washing machine can be more compact, and the size of the heat pump type washing machine can be smaller. Further optionally, the water inlet joint 445 is integrally formed with the two container lids 444. Further, a continuous annular convex rib 4441 extending along the thickness direction of the two-device cover 444 is formed at the edge of the accommodating port, an inner box 4442 is arranged on the inner side of the annular convex rib 4441, the water inlet joint 445 is communicated with the inner space of the inner box 4442, an annular gap is formed between the annular convex rib 4441 and the side wall of the inner box 4442, an annular blocking body 4444 is arranged in the annular gap, the annular blocking body 4444, the annular convex rib 4441 and the side wall of the inner box 4442 are in sealing connection, and a plurality of spraying ports c penetrating through the inner space of the annular convex rib 4441 and the inner box 4442 are formed on the side wall of the inner box 4442 facing the two-device air outlet b. Optionally, the annular blocking body 4444, the annular rib 4441 and the side wall of the inner box 4442 are fixed by ultrasonic welding to form a sealing connection. In order to facilitate the forming of the inner box body, the annular blocking body 4444 forms an annular groove or an annular step on one side of the lower surface of the two-piece box cover 444, the lower surface of the spray box is provided with a spray cover 447, the spray cover 447 is embedded into the annular rib 4441, one side of the spray cover 447, facing the spray box, is provided with an annular protrusion, and the annular protrusion is inserted into the bottom of the annular groove or the end part of the annular protrusion abuts against the annular step. The annular groove or the annular step plays a role in positioning the installation of the spraying cover 447, and optionally, the spraying cover 447 is fixed on the spraying box by means of ultrasonic welding. Preferably, the water inlet joint and the two box covers are integrally formed.

Further, the annular rib 4441, the inner box 4442 and the spraying cover 447 form the spraying box, or the inner box 4442 and the spraying cover 447 form the spraying box.

In another embodiment of this embodiment, the spraying box is a single piece, the side wall of the spraying box is provided with a rib plate which surrounds the spraying box for a circle and is perpendicular to the side wall of the spraying box, the two box cover 444 is provided with an accommodating opening, the spraying box is embedded into the accommodating opening, the rib plate is connected with the two box bodies 443 in a detachable sealing manner or in an ultrasonic welding sealing manner, and the rib plate blocks the accommodating opening. In this embodiment, the water inlet joint may be integrally formed with the shower box.

The upper surface of the two-unit cover 444 is a smooth surface, and/or the upper surface of the spray box is flush with the upper surface of the two-unit cover 444, and/or the lower surface of the two-unit cover 444 is provided with a continuous annular sealing protrusion 4443, the two-unit box body 443 is formed with a continuous annular sealing groove 4431 on the end surface of the opening, and the annular sealing protrusion 4443 is in sealing fit with the annular sealing groove 4431 to realize sealing and prevent the two-unit box from air leakage. The upper surfaces of the two box covers 444 are smooth surfaces, and the upper surfaces of the spraying boxes are flush with the upper surfaces of the two box covers 444, so that the distance between the two box covers 443 and the side wall of the shell of the heat pump washing machine can be smaller, and the size of the heat pump washing machine can be reduced.

As shown in fig. 7, in the washing machine of this embodiment, a first air duct 41 and a second air duct 42 communicated with the inside of the outer tub 23 are provided above the outer tub 23, the two boxes are provided above the outer tub 23, the first air duct 41 is communicated with the two-box air duct through the two-box air inlet a, the second air duct 42 is communicated with the two-box air duct through the two-box air outlet b, and a drying fan assembly 43 is provided in the first air duct 41 or the second air duct 42. The drying fan assembly 43 in this embodiment includes at least a fan.

Specifically, the front end of the outer cylinder 23 is provided with an air inlet of the two boxes of the outer cylinder, the rear end thereof is provided with an air outlet of the outer cylinder, a first air duct 41 is communicated with the air inlet of the two boxes of the outer cylinder, a second air duct 42 is communicated with the air outlet of the outer cylinder, when the heat pump washing machine dries clothes, the circulating air is adopted for drying, the damp and hot air in the outer barrel 23 is pumped out through the drying fan component 43 and is sequentially sent into the evaporator and the condenser, the evaporator is used for refrigerating and dehumidifying the damp and hot air, the spraying water of the spraying device is sprayed to the windward side of the evaporator, the flock attached to the evaporator in the drying process is removed, meanwhile, the condensation of the damp and hot air is accelerated, if the heat pump washing machine carries out the odor removal treatment on the clothes, the air with odor molecules meets condensation on the surface of the evaporator, meanwhile, the spray water accelerates the condensation speed and discharges the peculiar smell molecules condensed in the water through the water outlet.

EXAMPLE III

The present embodiment proposes a drying control method on the basis of the washing machines of the first and second embodiments, the washing machine of the present embodiment includes a drying program, the drying program includes a preheating phase and a drying phase; as shown in the control flowchart of fig. 8, the drying control method of the present embodiment includes steps S1 to S5, wherein:

s1, when the washing machine executes the drying program, the washing machine acquires the ambient temperature;

the washing machine of the present embodiment enters the drying process after completing the rinsing process or the dehydrating process upon receiving the washing/drying command. The time for entering the drying program is determined according to the material of the washing, and the drying program is directly entered after the rinsing program is finished aiming at the clothes material which is not suitable for being dried, such as wool and silk, and the drying program is entered after the dewatering program is finished for the clothes of other materials. And if the washing machine only receives the drying instruction, directly operating the drying program. In the initial stage of executing the drying program, the heat pump module is not started, the ambient temperature is obtained, whether the low-temperature environment is met or not is determined according to the ambient temperature, and if the low-temperature environment is met, the preheating stage is started. The embodiment has no limitation on the acquisition of the ambient temperature, and in some embodiments, the ambient temperature may be detected in real time by a separate ambient temperature sensor, and in other embodiments, the ambient temperature may also be determined by a temperature sensor carried by the washing machine itself.

S2, when the environment temperature is lower than the first set temperature, controlling the washing machine to enter a preheating stage;

in this embodiment, when the ambient temperature is lower than the first set temperature, it is determined that the current environment of the washing machine is lower than the environment, and if the heat pump system is directly started to dry, the drying efficiency is low, so that the heat pump system needs to be started after the ambient temperature of the washing machine is increased by a preheating stage, and the first set temperature is optionally 0 ℃ to 10 ℃, and preferably 5 ℃. When the ambient temperature is higher than the set temperature, the ambient temperature of the washing machine does not belong to the low-temperature environment, and the efficiency of heat pump drying is high, so that the heat pump system can be directly started.

S3, in the preheating stage, controlling the water level of the outer cylinder to be at a heating water level, and controlling the heating device to start heating;

this embodiment is through setting up electric heater unit in the urceolus bottom, pours into a small amount of water into to the urceolus again, and the water level of the urceolus normal water that pours into needs to reach the heating water level, and the heating water level satisfies to be higher than safe water level and is less than the highest water level, starts to come the water heating through control heating device to utilize the heat that produces behind the water heating to improve the inside ambient temperature of washing machine.

S4, acquiring the water temperature of the outer cylinder and the air inlet temperature of the evaporator, and controlling the heat pump system to start when the water temperature of the outer cylinder and the air inlet temperature of the evaporator respectively reach the set conditions for starting the heat pump system;

in the embodiment, when the water temperature in the outer barrel is low, steam cannot be generated to heat the environment in the barrel, the temperature of the environment in the barrel cannot be increased, and the heat pump system is started under the condition that the water temperature is insufficient, so that the drying efficiency is low. Meanwhile, the evaporator is used as a cold source, in the process of starting and warming up the heat pump system, the temperature of a copper pipe of the evaporator can be firstly reduced to be lower than the ambient temperature, and when the compressor is started to warm up under the condition of lower ambient temperature, the phenomenon that the temperature of the evaporator is too low to form frosting is easily caused, and the heat exchange effect is seriously influenced. Therefore, before the heat pump system is operated to heat up, the temperature of the evaporator needs to be detected, and when the temperature of the evaporator is high enough and frosting is not easy to occur after the drying system is started, the heat pump system can be started. Therefore, the heat pump system needs to be started after the water temperature of the outer cylinder and the temperature of the evaporator meet respective set conditions.

And S5, when the set condition for ending the preheating stage is reached, controlling the heating device to stop heating, and controlling the washing machine to enter the drying stage.

In this embodiment, when the set condition for ending the preheating stage is reached, it indicates that the internal environment temperature of the washing machine can already realize efficient heat pump drying, and at this time, the preheating stage can be ended, and the drying stage is entered, and the clothes are dried in the drying stage by adopting a heat pump drying method.

Further optionally, step S4 includes S41 to S43, where:

s41, respectively acquiring the water temperature of the outer cylinder and the air inlet temperature of the evaporator;

s42, when the water temperature of the outer barrel reaches a second set temperature, controlling the fan to start;

and S43, controlling the compressor to start when the air inlet temperature of the evaporator reaches a third set temperature.

In this embodiment, when the water temperature reaches the second set temperature, it is determined that steam is generated to heat the environment in the cylinder, and at this time, the fan is started to form circulating air, so that the environment in the cylinder is uniformly heated, the second set temperature is the temperature at which the water at the bottom of the cylinder is heated to generate the steam, and the second set temperature is not lower than 80 ℃; the third set temperature is a temperature limit value for preventing the evaporator temperature from being too low and frosting when the heat pump system operates, and is not lower than 20-30 ℃.

Further optionally, step S3 includes the following two schemes:

the first scheme comprises the following steps: after the washing machine finishes washing, the outer cylinder is controlled to drain water to a heating water level, and then the water drainage is stopped.

In this embodiment, after the washing machine receives the washing and drying instruction, the washing machine washes the laundry first, and sequentially executes the washing stage and the rinsing stage, or sequentially executes the washing stage, the rinsing stage, and the dewatering stage. If the clothes are washed in the last stage, such as the rinsing stage or the dewatering stage, the water in the outer barrel is not drained during rinsing drainage or dewatering drainage, but is drained to the heating water level, and the heating device is directly started to heat after the set condition of entering the preheating stage is detected, so that water does not need to be injected. If the environment temperature in the washing machine is detected to be higher, the water in the outer cylinder is emptied without executing a preheating stage.

Scheme II: after the washing machine enters a drying program, the water inlet valve is controlled to feed water to a heating water level, and then the water feeding is stopped.

In this embodiment, after the clothes enter the drying stage, when the internal environment temperature of the washing machine is detected to be low and the preheating stage needs to be executed, the water inlet of the washing machine is controlled to reach the heating water level. One way to implement the method is that the water flowing out of the water inlet valve enters the outer cylinder from the inner cylinder; the other practical mode is that the water inlet valve is communicated with the condensed water pipeline, the condensed water pipeline is communicated with the bottom of the outer barrel, water flowing out of the water inlet valve enters the bottom of the outer barrel through the condensed water pipeline, and the water stops entering after the water enters the heating water level, so that the phenomenon that the water enters the outer barrel from the inner barrel to further wet clothes is avoided, the water content of the clothes is increased, and the drying time is prolonged.

The specific scheme is as follows: and controlling the water inlet valve to feed water according to a set water inlet time sequence, and stopping feeding water when the water is fed to the heating water level.

The reason for water inflow in the set water inflow time sequence in the embodiment is that the water inflow valve is opened for a long time and is easy to generate a large water flow, and when the water flows into the space of the outer cylinder through the condensed water channel, the water impacts the wall surface of the outer cylinder so as to splash into the inner cylinder. Therefore, water needs to be fed in an intermittent switch mode, the opening and stopping time relation is determined by the relation between the flow q1 of the water inlet valve and the maximum water flow q2 of the condensed water channel entering the space of the outer barrel, and q1 × A is less than or equal to q2 × B, wherein A is the time for opening the water inlet valve, and B is the time for closing the water inlet valve, so that the condensed water channel is prevented from being submerged too fast and even spreading to other places.

Further optionally, the inner barrel is controlled to rotate at the first rotation speed in the process of controlling the water inlet valve to feed water according to the set water inlet time sequence.

In the embodiment, the inner drum rotates at the first rotating speed when water enters, so that the probability of splashing into the inner drum when water enters can be reduced, but the rotating speed is too high, the centrifugal force is large, and clothes are easy to wrinkle, so that the range of the first rotating speed is limited to 60-120 RPM, and preferably 90 RPM.

Further optionally, during the preheating stage, the water temperature is maintained within the set temperature range by controlling the heating device to start heating and stop heating, including steps P1 to P2, wherein:

p1, continuously acquiring the water temperature at the bottom of the outer cylinder;

p2, when the water temperature at the bottom of the outer cylinder reaches the first set water temperature, controlling the heating device to heat at a set heating time sequence, wherein the set heating time sequence comprises: stopping heating when the water temperature rises to a second set water temperature, and recovering heating when the water temperature drops to a third set water temperature; the first set water temperature is less than or equal to the third set water temperature and less than the second set water temperature.

In this embodiment, when the water temperature T is greater than or equal to the first set water temperature, the heating device is controlled to turn on the water heater in a timing sequence of turning on the third set water temperature and turning off the water heater in the timing sequence of turning off the second set water temperature, the heating device stops heating when turning on the water heater to heat the drum bottom water to the second set water temperature, and the heating is resumed when the water temperature drops to the third set water temperature, so that the water temperature can be maintained within a suitable range, and the continuous generation of steam is ensured while the energy consumption is reduced.

Further optionally, in the preheating stage, the control method in this embodiment further includes controlling the inner barrel to rotate forward and backward alternately at a second rotation speed under a certain rotation-stop ratio, where the first rotation speed is greater than or equal to the second rotation speed.

In the embodiment, the inner barrel is controlled to rotate forward and backward alternately at a lower rotating speed in the preheating stage, so that the clothes in the inner barrel can be uniformly preheated, wherein the inner barrel rotates at a first higher rotating speed to prevent water from splashing into the inner barrel when water enters, and the inner barrel rotates at a lower rotating speed to enable hot air to better enter the clothes to increase the temperature of the surfaces of the clothes when the water is heated.

Further optionally, in the control method in this embodiment, in the preheating stage, it is further monitored whether the water level at the bottom of the outer tub is lower than the safe water level L, and if the water level is lower than the safe water level L, the heating device is controlled to stop heating; judging whether the end condition of the preheating stage is reached, and if the end condition of the preheating stage is reached, ending the preheating stage; if the condition of ending the preheating stage is not met, controlling the water inlet valve to replenish water to a heating water level R, and controlling the heating device to start heating again, so that the heating device is always in a safe water level range, and the heating device is prevented from being burnt dry, wherein the safe water level L is more than the heating water level R and is less than or equal to a highest water level H;

further alternatively, as in the control flowchart shown in fig. 9, the determination of reaching the set condition for ending the warm-up phase in step S5 includes two ways to make the determination.

The method I comprises the following steps: comprising a step S51, wherein

And S51, judging that the set condition for ending the preheating stage is reached when the temperature of the air inlet of the evaporator rises to a fourth set temperature by acquiring the temperature of the air inlet of the evaporator. The fourth set temperature is the temperature at which the heat pump system can normally work, when the temperature is reached, the temperature rise stage of the compressor is judged to be finished, the heat pump system enters the formal drying stage, and the fourth set temperature is not lower than 30 ℃.

The second method includes steps S51-S52, wherein:

s51', acquiring the temperature of an air inlet and the temperature of an air outlet of the outer cylinder;

s52', when the air inlet temperature reaches a second set temperature, calculating the temperature difference delta T between the air inlet temperature and the air outlet temperature; and when the delta T is less than or equal to the set temperature difference, controlling the heating device to stop heating, controlling the outer cylinder to drain water to the water level of the empty cylinder, and ending the preheating stage.

In this embodiment, when the air inlet temperature of the outer tub reaches the second set temperature, it indicates that the heating device heats the heat generated by the water, and gives out air in the preheating stage, the air inlet and outlet temperature difference is large, and as the preheating proceeds, the air inlet and outlet temperature difference becomes small, and when the air inlet and outlet temperature difference of the outer tub is smaller than or equal to the set temperature difference, it indicates that the air inlet and outlet temperature is close, and the clothes in the inner tub are uniformly heated, and the internal environment of the washing machine reaches the temperature condition capable of performing efficient heat pump drying, and at this time, the preheating stage is finished.

In this embodiment, after the preheating stage is finished, the washing machine is controlled to enter a formal drying stage, the drying stage is finished when a dry judgment condition is met, the cooling stage is entered, and the cooling stage is finished when a set condition for finishing the cooling stage is met, so that the whole drying program is finished.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A washing machine with a heat pump drying function is characterized by comprising an outer barrel and an inner barrel which is rotatably arranged in the outer barrel, wherein a heating device is arranged at the bottom of the outer barrel;

the washing machine further comprises a drying system and a control system, wherein the drying system comprises a drying fan, a compressor, an evaporator and a condenser, when the washing machine executes a drying program, the control system controls to obtain the ambient temperature, and when the ambient temperature is lower than a first set temperature, the control system controls the washing machine to enter a preheating stage; in the preheating stage, the control system controls the water level of the outer barrel to be at a heating water level and controls the heating device to start heating; the control system also obtains the water temperature of the outer cylinder and the temperature of the air inlet of the evaporator, and when the water temperature of the outer cylinder and the temperature of the air inlet of the evaporator reach the set conditions for starting the heat pump system, the control system controls the heat pump system to start; when the set condition of finishing the preheating stage is reached, the control system controls the heating device to stop heating and controls the washing machine to enter a drying stage.

2. The washing machine as claimed in claim 1, further comprising a water inlet valve, wherein the drying system comprises a condensed water passage, one end of the condensed water passage is communicated with the water inlet valve, and the other end of the condensed water passage extends along the wall of the outer tub to be communicated with the bottom of the outer tub;

3. A drying control method of a washing machine according to claim 1 or 2, wherein the washing machine includes a drying course including a preheating phase and a drying phase; the control method comprises the following steps:

acquiring the water temperature of the outer cylinder and the air inlet temperature of the evaporator, and controlling the heat pump system to start when the water temperature of the outer cylinder and the air inlet temperature of the evaporator respectively reach set conditions for starting the heat pump system;

4. The drying control method of a washing machine according to claim 3, wherein said obtaining the tub water temperature and the evaporator intake temperature controls the heat pump system to be started when the tub water temperature and the evaporator intake temperature respectively reach the setting conditions for starting the heat pump system, including

5. The drying control method of a washing machine according to claim 4, wherein the set condition for reaching the end of the warm-up phase comprises

6. The drying control method of a washing machine according to claim 3, wherein the controlling of the water level of the tub at the heating water level comprises

After the washing machine finishes washing, controlling the outer cylinder to drain water to a heating water level and then stopping draining;

7. The drying control method of a washing machine as claimed in claim 6, wherein the controlling of the water supply valve to supply water to the heating water level and stopping the water supply after the washing machine enters the drying process comprises

And controlling the water inlet valve to feed water according to a set water inlet time sequence, and stopping feeding water when the water is fed to the heating water level.

8. The drying control method of a washing machine as claimed in claim 7, wherein the inner tub is further controlled to rotate at the first rotation speed during the water supply by controlling the water supply valve to supply the water at the set water supply timing.

9. The drying control method of a washing machine according to claim 8, wherein the control method further comprises

10. The drying control method of a washing machine according to claim 3, wherein the control method further comprises: in the process of the preheating stage, the water temperature is maintained within a set temperature range by controlling the heating device to start and stop heating.

11. The drying control method of a washing machine according to claim 10, wherein the control method further comprises