CN111058220A

CN111058220A - Washing machine and control method thereof

Info

Publication number: CN111058220A
Application number: CN202010022518.0A
Authority: CN
Inventors: 李海杰; 赖毅俊; 司富美; 卢挺浩; 何祥根; 傅晓勇
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2019-11-02
Filing date: 2020-01-09
Publication date: 2020-04-24
Anticipated expiration: 2040-01-09
Also published as: CN212152785U; CN111088645A; CN111235818B; CN111088641B; CN111088640B; CN111058220B; CN111088646A; CN111118808A; CN111074477A; CN111074473A; CN211815025U; CN111088644A; CN111197225A; CN111394931A; CN212152790U; CN212152793U; CN111155267A; CN111139620A; CN111074474A; CN111394932A

Abstract

The invention relates to a washing machine, which comprises one or more washing barrels, wherein each washing barrel is provided with a circulating water inlet pipe and a circulating water outlet pipe, and an instant water heater, the circulating water inlet pipe and the circulating water outlet pipe of each washing barrel are connected to the instant water heater, the instant water heater is connected with a total water inlet pipe, and tap water enters the instant water heater through the total water inlet pipe to be heated and then flows into the washing barrel. The instant water heater is provided with an electromagnetic heating device which is used for heating washing water. The electromagnetic heating device is adopted to replace the prior PTC heating device, so that the normal temperature water is quickly heated to the washing water within 50 ℃, and the overall efficiency and performance of the washing machine are improved. When the washing temperature is required to be higher than 50 ℃, water circulation is started to pump the 50 ℃ water which originally flows into the barrel back to the instant heating type heater for secondary heating, so that the water in the washing barrel continuously flows through the electromagnetic instant heating type heating device, and the washing water circulation reaches the specified washing temperature.

Description

Washing machine and control method thereof

Technical Field

The invention relates to a washing machine and a control method thereof, in particular to an instant heating type washing machine and a control method thereof, and belongs to the technical field of washing equipment.

Background

With the continuous improvement of living standard, the washing machine has already gone into thousands of households, and becomes an important component in daily life of the family. In the development process of the whole washing machine, the washing temperature of the washing machine is from the beginning of normal-temperature washing of tap water to the high-temperature washing realized by heating the tap water in a washing barrel by the common PTC heating pipe, so that the washing quality is improved, and the washing machine has the washing effect of high-temperature sterilization.

Washing temperatures of washing machines are nowadays generally maintained at 40-50 ℃. The tap water is heated to 40-50 ℃ by the PTC heating device after entering the barrel, the heating process needs a certain time, when the washing temperature of a user is required to reach 60-80 ℃, even 95 ℃ in a barrel self-cleaning mode, the heating process of the tap water by the PTC heating device occupies most time of the whole washing process, and the high-temperature washing efficiency of the washing machine is greatly reduced. The PTC heating tube is slowly heated in the prior heating application of the washing machine. At present, most heating devices of washing machines are generally PTC heating tubes. When a user uses high-temperature washing, the PTC heating pipe can heat tap water for a long time, even if the temperature is 40-50 ℃ in general, the heating time is about 40 minutes. When the washing temperature is higher, the heating time is longer, and the washing efficiency is greatly reduced. The PTC heating tube is not highly safe. The PTC heating device is an electric heating wire heating device, which can not realize water and electricity separation in principle, and even though the development of the existing washing machine has multiple safety level limits on PTC, certain potential safety hazards still exist.

And PTC heating device is that heavy current passes through the metal heater, makes the metal generate heat and heats the running water and heat up, can not realize water and electricity separation, is the most intractable safety problem in the aspect of the washing machine safety level requirement now.

Disclosure of Invention

In view of this, the present invention provides a washing machine and a control method thereof. The washing machine provided by the invention is provided with the instant heating type water heater, the instant heating type water heater is arranged independently for each washing barrel of the fish washing machine, and the instant heating type heating can be carried out on water flowing into each washing barrel.

Specifically, the method comprises the following steps:

the invention relates to a washing machine, which comprises an instant water heater and one or more washing barrels, wherein each washing barrel is provided with a water inlet pipe and a water outlet pipe, the water inlet pipe and the water outlet pipe of each washing barrel are connected to the instant water heater, the instant water heater is connected with a total water inlet pipe and a total water outlet pipe, and tap water enters the instant water heater through the total water inlet pipe to be heated and then flows into the total water outlet pipe and is distributed to the corresponding washing barrel water inlet pipe.

Further optionally, the instantaneous water heater adopts an electromagnetic heating device, and the electromagnetic heating device is used for heating the washing water flowing through the instantaneous water heater.

Further alternatively, the electromagnetic heating device may be adapted to adjust the heating power in response to the heating requirements of a plurality of washing tubs.

Further optionally, a water flow adjusting device is arranged on the main water inlet pipe, and the water flow adjusting device is used for adjusting the amount of water entering the instant water heater; the main water inlet pipe is also provided with an electromagnetic main water inlet valve, and the water outlet end of the electromagnetic main water inlet valve is arranged on the water inlet side of the water flow regulating device.

Further optionally, a high-temperature circulating pump and a one-way check valve are arranged on the water outlet pipeline of each washing barrel, and a water inlet of the one-way check valve is arranged at a water outlet end of the high-temperature circulating pump and only allows water in the water outlet pipeline of the washing barrel to flow to the instant water heater.

Further optionally, the total water outlet pipe is connected with each washing barrel water inlet pipe; the water inlet valve is arranged on the water inlet pipe of each washing barrel and used for controlling the communication state of the main water outlet pipe and the washing barrel corresponding to the water inlet valve.

Further optionally, the washing machine includes three washing tubs, which are a first washing tub, a second washing tub and a third washing tub, respectively; the three washing barrels are provided with circulating water inlet pipes and circulating water outlet pipes, and the instant water heater is connected with a main water inlet pipe and a main water outlet pipe;

the main water inlet pipe is provided with a water flow adjusting device which is used for adjusting the water flow speed and/or water quantity entering the instant water heater; the main water inlet pipe is also provided with a main water inlet valve, and the water outlet end of the main water inlet valve B50 is arranged at the water inlet of the water flow adjusting device and is used for controlling the opening and closing of the main water inlet pipe;

the main water outlet pipe is connected with the circulating water inlet pipes of the three washing barrels, and the circulating water inlet pipe of each washing barrel is provided with a water inlet valve for controlling the communication state of the main water outlet pipe and the circulating water inlet pipe where the water inlet valve is located; the circulating water outlet pipe of each washing barrel is connected with the instant water heater, and a one-way check valve and a high-temperature circulating pump are arranged on the circulating water outlet pipe of each washing barrel.

The invention also relates to a control method of the washing machine, which comprises the following heating control steps:

s1: starting a heating program for a single washing barrel;

s2: judging whether the set temperature T2 of the washing barrel needing to be heated is more than or equal to the preset critical temperature A needing to be heated for the second time or not;

s31: if the judgment result of the S2 is yes, opening a main water inlet valve to feed water into the washing barrel, controlling the instant heating type heater to keep constant preset power P1 to heat the washing water flowing through the instant heating type water heater from the main water inlet pipe for the first time to an initial temperature T1, and stopping feeding water when the washing water of the washing barrel reaches a set water level; adjusting the power of the instant heater from P1 to P2, controlling the washing water of the washing barrel to circulate between the instant water heater and the washing barrel, continuously heating the washing water in the circulation process until the temperature of the washing water reaches a set temperature T2, stopping heating, and circulating all the washing water back to the washing barrel;

s32: if the judgment result of the S2 is ' NO ', opening the main water inlet valve to feed water into the washing barrel, and controlling the instant heating type heater to keep constant preset power P1' to heat the washing water flowing through the instant heating type water heater from the main water inlet pipe for the first time; and stopping water feeding and heating until the washing water in the washing barrel reaches a set water level.

s1: starting a heating program for at least two washing barrels;

s2: the following judgment procedure is performed for all the washing tubs to be heated: judging whether the set temperature T2 of the washing barrel entering the heating program is more than or equal to the preset critical temperature A needing secondary heating or not;

s31: if the judgment result of S2 is that the washing barrel is 'yes', the total water inlet valve is opened to respectively or simultaneously feed water into the washing barrel, when each washing barrel with the judgment result of 'yes' enters water, the instantaneous water heater is controlled to keep constant preset power P1 to heat the washing water flowing through the instantaneous water heater from the total water inlet pipe for the first time to the initial temperature T1, the water feeding is stopped when the washing water of the washing barrel reaches the set water level, the washing water of each washing barrel with the judgment result of 'yes' is controlled to circulate between the instantaneous water heater and the corresponding washing barrel, the washing water is continuously heated by the instantaneous water heater during circulation, the circulation is only carried out between one washing barrel and the instantaneous water heater each time, the heating power of the instantaneous water heater is adjusted to be increased from P1 to P2 corresponding to the washing barrel with the judgment result of 'yes' during execution of each circulation until the temperature of the washing water reaches the set temperature T2 of the corresponding washing barrel, stopping heating and circulating all the washing water back to the corresponding washing barrel;

s32: if the judgment result of the S2 is the washing barrel with the 'no' judgment result, opening the main water inlet valve to feed water into the washing barrel with the 'no' judgment result; and when each washing barrel with the judgment result of ' no ' is used for water inlet, controlling the instant heating type heater to keep the preset power P1' corresponding to the washing barrel when water is fed, heating the washing water flowing through the instant heating type water heater from the main water inlet pipe for the first time until the washing water in the washing barrel reaches the set water level, and stopping the main water inlet pipe from feeding the water into the washing barrel and stopping the instant heating type water heater from heating.

Further optionally, the following heating control steps are included:

in step S32, when there are at least two washing tubs with the no result, corresponding to the same preset power P1', the washing tubs with the same preset power P1' are controlled to simultaneously enter water; when water is fed, the instantaneous water heater is controlled to heat water flowing through the instantaneous water heater with power P1', and when the washing water in any washing barrel reaches a set water level, the water feeding into the washing barrel is stopped;

and controlling the main water inlet pipe to stop water inlet until all the corresponding washing barrels with the same preset power P1' have water inlet to a set water level, and stopping heating the instant water heater.

Advantageous effects

The washing machine provided by the invention heats each washing barrel in the washing machine based on an electromagnetic instant heating mode, and when the washing temperature is required to be below 50 ℃, tap water entering the barrel can reach the washing designated temperature immediately through the electromagnetic instant heating type water heater. Compared with PTC heating, the washing machine provided by the invention is provided with the electromagnetic instant water heater to heat the washing water, so that the washing time is greatly shortened, and the heating efficiency is improved.

If the specified washing temperature is higher than 50 ℃, a high-temperature circulating pump between the washing barrel and the electromagnetic instant water heater can be connected in an operating mode, and hot water which originally passes through the electromagnetic instant water heater only once and reaches 50 ℃ in the washing barrel is circulated to the electromagnetic instant water heater through the high-temperature circulating pump to be heated secondarily. The water in the barrel is continuously heated and heated through the electromagnetic instant heating type water heater under the action of the high-temperature circulating pump until the washing water reaches the washing temperature set by the washing barrel, the high-temperature water suction pump stops working, the heating work of the electromagnetic instant heating type water heater is stopped, and then the washing task is executed.

The water circulation system using the high-temperature water pump is used in cooperation with an electromagnetic instant water heater, water entering a barrel has a high temperature of 50 ℃, when the water is heated to 60-80 ℃ or even higher temperature of 95 ℃, because the water entering the barrel has a high temperature of 50 ℃ and is matched with the operation of the water circulation system, the time required by high-temperature washing is shortened by about 50%, the heating efficiency of washing water in the washing barrel can be improved, the overall heating time of the washing machine is saved, and the performance of the washing machine is improved. The electromagnetic instant heating type water heater is independently arranged with each washing barrel, water and electricity separation in the washing process is realized, the safety of the washing machine is enhanced, the washing water of a plurality of washing barrels can be quickly heated, meanwhile, the operation power of the washing machine is not too high, and the service life of the washing machine and the electricity utilization safety in the practical process are prolonged. Note: the washing temperature, 50 c being generally required here, is used only as an example and is not intended to limit the present invention.

The electromagnetic instant water heating device has the advantages of safer water-electricity separation, higher heat conversion efficiency and more energy conservation.

Drawings

The above and other objects, features and advantages of the present disclosure will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings. The drawings described below are merely exemplary embodiments of the present disclosure, and other drawings may be derived by those skilled in the art without inventive effort.

FIG. 1 is a schematic view of a water circuit system of a washing machine having a plurality of washing tubs according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a water circuit system of a single wash tub washing machine in an embodiment of the present invention;

FIG. 3 is a control logic diagram in an embodiment of the present invention;

FIG. 4 is a control logic diagram of a first electromagnetic instant heating routine in an embodiment of the present invention;

FIG. 5 is a control logic diagram of a second electromagnetic instant heating routine in an embodiment of the present invention;

in the figure:

A10-Single tub washing machine; A11-Single bucket Total Water Inlet valve; a12-single bucket water flow regulating device; a13-single-barrel electromagnetic instant heating type water heater; A14-Single barrel circulating water inlet valve; a15-washing tub; A16-Single bucket temperature sensor; a17-single barrel high temperature circulating pump; a18-single bucket one-way check valve;

b10 — first washing tub; b11-first inlet valve; b12 — first high temperature circulating pump; b13-first one-way check valve; b14 — first temperature sensor; b15-first circulation inlet pipe; b16-first circulation outlet pipe;

b20 — second washing tub; b21-second inlet valve; b22-second high temperature circulating pump; b23-second one-way check valve; b24 — second temperature sensor; b25-second circulation water inlet pipe; b26-second circulation outlet pipe;

b30-third washing tub; b31 — third water inlet valve; b32-third high-temperature circulating pump; b33-third one-way check valve; b34 — third temperature sensor; b35-third circulation water inlet pipe; b36-third circulation outlet pipe;

b40-multi-barrel electromagnetic instant heating type water heater; B50-Total Inlet valve; b51-total outlet pipe; b60-water flow regulating device; b70-total outlet pipe; w-tap water;

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the examples of the present invention and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, and "a" and "an" generally include at least two, but do not exclude at least one, unless the context clearly dictates otherwise.

It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a good or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such good or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a commodity or system that includes the element.

[ example 1 ]

The present embodiment describes a schematic diagram of a water circuit system of a washing machine according to the present embodiment in detail with reference to fig. 1 to 2. The washing machine in the present embodiment may include a plurality of washing tubs or a single washing tub.

As shown in fig. 1, when three washtubs are included, the tankless type washing machine is provided with a first washtub B10, a second washtub B20, and a third washtub B30.

Each washing barrel is provided with a circulating water inlet pipe and a circulating water outlet pipe, a multi-barrel electromagnetic instant water heater B40 is arranged in the washing machine, the circulating water inlet pipe and the circulating water outlet pipe of each washing barrel are connected to a multi-barrel electromagnetic instant water heater B40, the instant water heater is connected with a total water inlet pipe, and tap water enters the multi-barrel electromagnetic instant water heater B40 through the total water inlet pipe to be heated and then flows into the washing barrel.

The multi-tub electromagnetic instantaneous water heater B40 is provided with an electromagnetic heating device for heating the washing water flowing through the multi-tub electromagnetic instantaneous water heater B40. The heating power of the electromagnetic heating device is adjustable and is arranged on the instant water heater.

A water flow adjusting device B60 is arranged on the main water inlet pipe, and a water flow adjusting device B60 is used for adjusting the speed and/or the quantity of water entering the instant water heater; a main water inlet valve B50 is also arranged on the main water inlet pipe, and the water outlet end of the main water inlet valve B50 is arranged at the water inlet of a water flow adjusting device B60.

The circulating water outlet pipeline of each washing barrel is provided with a high-temperature circulating pump and a one-way check valve, and the water inlet of the one-way check valve is arranged at the water outlet end of the high-temperature circulating pump. Each circulation water inlet pipe is provided with a water inlet valve which is used for controlling the communication state of the circulation water inlet pipe and the corresponding washing barrel.

Specifically, the method comprises the following steps:

the first washtub B10 is provided with a first temperature sensor B14 for measuring the temperature of the washing water in the tub. The first washtub B10 is connected with a first circulation outlet pipe B16 and a first circulation inlet pipe B15. A first high-temperature circulating pump B12 is arranged in the first circulating water outlet pipe B16 and is used for realizing circulation between the washing water in the first washing barrel and the multi-barrel electromagnetic instant heating type water heater B40. The first circulating water outlet pipe B16 is provided with a first one-way check valve B13 to prevent the washing water from flowing back to the first washing barrel B10 when flowing out of the first circulating water outlet pipe B16, so as to weaken the effect of circulating heating. The first circulation inlet pipe B15 is also provided with a first inlet valve B11 for controlling circulation inlet water to the first washing tub B10 and controlling the inlet water amount from the main inlet pipe B51 to the first washing tub.

Other second and third washtubs all have the setting of corresponding pipeline and valve body, and the effect is the same, and no longer redundance here.

Circulating water outlet pipes of the first washing barrel, the second washing barrel and the third washing barrel are all connected with a multi-barrel electromagnetic instant heating type water heater B40, and the multi-barrel electromagnetic instant heating type water heater B40 is used for heating washing water in all the washing barrels. The main water inlet pipe B51 is provided with a water flow adjusting device B60 which is used for adjusting the water inflow or the water flow speed of the main water inlet pipe. The main water inlet valve B50 is used for controlling the communication state of the main water inlet pipe B51.

Fig. 2 is a schematic view of a waterway system having a single-tub washing machine. A single-barrel total water inlet valve A11 and a single-barrel water flow adjusting device A12 are arranged on a total water inlet pipeline of the single-barrel washing machine A10, and a single-barrel electromagnetic instant water heater A13 is arranged on the single-barrel washing machine A10. The circulating water inlet pipeline of the washing tub A15 is also provided with a single-tub circulating water inlet valve A14, and the washing tub A15 is also provided with a single-tub temperature sensor A16. The circulating water outlet pipe of the washing tub A15 is also provided with a single-tub high-temperature circulating pump A17 and a single-tub one-way check valve A18 arranged at the water outlet side of the single-tub high-temperature circulating pump A17.

[ 1-a ] control method of single-tub washing machine

S1: starting a heating program for a single washing barrel;

Further explained by specific examples, in the critical temperature a preset to be heated secondarily in the embodiment, a is 50 ℃, when the set washing temperature in a single washing tub is less than or equal to 50 ℃, the single tub main water inlet valve a11 of the single tub washing machine a10 is opened to feed water, tap water firstly flows into the single tub electromagnetic instant heating type water heater a13, and at this time, the single tub electromagnetic instant heating type water heater a13 performs instant heating on water flowing through the single tub electromagnetic instant heating type water heater a 13. The single-barrel electromagnetic instant heating type water heater A13 can instantly heat tap water to 50 ℃, when the water level in the washing barrel A15 reaches a preset or set water level, the water temperature in the washing barrel A15 is also 50 ℃, a washing program can be immediately entered, an advanced water reheating method is not needed, the washing time is greatly shortened, the time is shortened by 50% compared with that of a PTC heating device, and the energy-saving and high-efficiency effects are achieved.

When the set washing temperature in a single washing barrel is higher than 50 ℃, a single-barrel main water inlet valve A11 of a single-barrel washing machine A10 is opened to feed water, tap water firstly flows into a single-barrel electromagnetic instant heating type water heater A13, and the single-barrel electromagnetic instant heating type water heater A13 carries out instant heating on the water flowing through the single-barrel electromagnetic instant heating type water heater. The single-barrel electromagnetic instant water heater A13 can instantly heat tap water to 50 ℃, and when the water level in the washing barrel A15 reaches a preset or set water level, the water temperature in the washing barrel A15 is also 50 ℃. At the moment, the power of the electromagnetic heating device on the single-barrel electromagnetic instant water heater A13 is adjusted to be increased from P0 to P1, the single-barrel high-temperature circulating pump A17 is started to circulate the washing water with a certain temperature in the barrel to the single-barrel electromagnetic instant water heater A13, the circulation is stopped after the water is continuously heated to the set washing temperature, the heating is stopped, all the washing water is circulated back to the washing barrel, and the washing task is executed.

[ 1-b ] control method of multi-tub instant heating type washing machine

S1: starting a heating program for at least two washing barrels;

Further optionally, the following heating control steps are included:

To further illustrate by specific examples, when the washing machine includes three washing tubs, in the critical temperature a preset to be heated for the second time in the embodiment, a is 50 ℃, and when two of the three washing tubs have a set washing temperature of 50 ℃ or less and a set washing temperature of one washing tub is greater than 50 ℃, for example, only the first washing tub needs water with a temperature of 50 ℃ or more, and the other two washing tubs only need water with a temperature of 40 ℃ to 50 ℃. The main water inlet valve B50 is opened, the water flow adjusting device B60 is opened, the multi-barrel electromagnetic instant water heater B40 heats the water flowing through the multi-barrel electromagnetic instant water heater B40 with preset power P1, and the output water with the temperature of 40-50 ℃ flows into 3 washing barrels through the first water inlet valve B11, the second water inlet valve B21 and the third water inlet valve B31 respectively. When the three washing tubs are filled with water, the second water inlet valve B21 and the third water inlet valve B31 are closed, and the second and third washing tubs start to wash. The first high-temperature circulating pump B12 pumps water in the first washing tub back to the multi-barrel electromagnetic instant heating type water heater B40 for reheating, at the moment, the power of the multi-barrel electromagnetic instant heating type water heater B40 is controlled to be increased from P1 to P2, the multi-barrel electromagnetic instant heating type water heater B40 reheats the water flowing through the first washing barrel until the water is heated to the set temperature T2 of the first washing barrel, the heating of the multi-barrel electromagnetic instant heating type water heater B40 on the water is stopped, the first high-temperature circulating pump B12 is controlled, the opening state of the first water inlet valve B11 is kept, the water is sent back to the first washing barrel B10, and the heating program is stopped. Note: here, the washing temperature of 50 ℃ is generally required and is used only as an example, and is not limited to the value of the critical temperature a preset to be heated again in this embodiment.

Exemplary embodiments of the present disclosure are specifically illustrated and described above. It is to be understood that the present disclosure is not limited to the precise arrangements, instrumentalities, or instrumentalities described herein; on the contrary, the disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. The washing machine is characterized by comprising an instant water heater and one or more washing barrels, wherein each washing barrel is provided with a water inlet pipe and a water outlet pipe, the water inlet pipe and the water outlet pipe of each washing barrel are connected to the instant water heater, the instant water heater is connected with a total water inlet pipe and a total water outlet pipe, and tap water enters the instant water heater through the total water inlet pipe to be heated and then flows into the total water outlet pipe and is distributed to the corresponding washing barrel water inlet pipe.

2. The washing machine as recited in claim 1, wherein the tankless water heater employs an electromagnetic heating device for heating wash water flowing through the tankless water heater.

3. A washing machine as claimed in claim 2 wherein the electromagnetic heating means is adjustable for respective heating power in response to heating demand of the plurality of washing tubs.

4. A washing machine as claimed in claim 3 wherein the mains water inlet is provided with a water flow regulating means for regulating the amount of water entering the tankless water heater; the main water inlet pipe is also provided with an electromagnetic main water inlet valve, and the water outlet end of the electromagnetic main water inlet valve is arranged on the water inlet side of the water flow regulating device.

5. The washing machine as claimed in claim 4, wherein a high temperature circulating pump and a one-way check valve are disposed on the water outlet pipeline of each washing tub, and a water inlet of the one-way check valve is disposed at a water outlet end of the high temperature circulating pump to only allow water in the water outlet pipeline of the washing tub to flow to the tankless water heater.

6. A washing machine as claimed in claim 5 wherein said main outlet pipe is connected to each of said washing tub inlet pipes; and a water inlet valve is arranged on the water inlet pipe of each washing barrel and is used for controlling the communication state of the main water outlet pipe and the washing barrel corresponding to the water inlet valve.

7. The washing machine as claimed in claim 6, wherein the washing machine comprises three washing tubs, a first washing tub, a second washing tub and a third washing tub; the three washing barrels are provided with circulating water inlet pipes and circulating water outlet pipes, and the instant water heater is connected with the main water inlet pipe and the main water outlet pipe;

the main water inlet pipe is provided with a water flow adjusting device for adjusting the water flow speed and/or water quantity entering the instant water heater; a main water inlet valve is also arranged on the main water inlet pipe, and the water outlet end of the main water inlet valve B50 is arranged at the water inlet of the water flow adjusting device and is used for controlling the opening and closing of the main water inlet pipe;

the total water outlet pipe is connected with the circulating water inlet pipes of the three washing barrels, and the circulating water inlet pipe of each washing barrel is provided with a water inlet valve for controlling the communication state of the total water outlet pipe and the circulating water inlet pipe where the water inlet valve is located; and the circulating water outlet pipe of each washing barrel is connected with the instant heating type water heater, and a one-way check valve and a high-temperature circulating pump are arranged on the circulating water outlet pipe of each washing barrel.

8. A control method of a washing machine according to any one of claims 1 to 7, comprising the heating control steps of:

s1: starting a heating program for a single washing barrel;

s31: if the judgment result of the S2 is 'yes', a main water inlet valve is opened to feed water into the washing barrel, the instant heating type heater is controlled to keep constant preset power P1 to heat the washing water flowing through the instant heating type water heater from the main water inlet pipe for the first time to an initial temperature T1, and the water feeding is stopped when the washing water of the washing barrel reaches a set water level; adjusting the power of the instantaneous heater to be increased from P1 to P2, controlling the washing water of the washing barrel to circulate between the instantaneous heater and the washing barrel, continuously heating the washing water during circulation until the temperature of the washing water reaches the set temperature T2, stopping heating, and circulating all the washing water back to the washing barrel;

s32: if the judgment result of the S2 is ' NO ', opening a main water inlet valve to feed water into the washing barrel, and controlling the instant heating type heater to keep constant preset power P1' to heat the washing water flowing through the instant heating type water heater from a main water inlet pipe for the first time; and stopping water feeding and heating until the washing water in the washing barrel reaches a set water level.

9. A control method of a washing machine according to any one of claims 1 to 7, comprising the heating control steps of:

s1: starting a heating program for at least two washing barrels;

s2: executing the following judgment procedures on all the washing barrels needing to be heated: judging whether the set temperature T2 of the washing barrel entering the heating program is more than or equal to a preset critical temperature A needing secondary heating or not;

s31: if the judgment result of S2 is that the washing barrel is 'yes', the general water inlet valve is opened to respectively or simultaneously feed water into the washing barrel, when each washing barrel with the judgment result of 'yes' is fed with water, the instantaneous water heater is controlled to keep constant preset power P1 to heat the washing water flowing through the instantaneous water heater from the general water inlet pipe for the first time to the initial temperature T1, the water feeding is stopped when the washing water of the washing barrel reaches the set water level, the washing water of each washing barrel with the judgment result of 'yes' is controlled to circulate between the instantaneous water heater and the corresponding washing barrel, the washing water is continuously heated during circulation, the circulation is only carried out between one washing barrel and the water heater at each time, the heating power of the instantaneous water heater is adjusted to be increased from P1 to P2 corresponding to each washing barrel with the judgment result of 'yes', stopping heating until the temperature of the washing water reaches the set temperature T2 of the corresponding washing tub, and circulating all the washing water back to the corresponding washing tub;

10. The control method of a washing machine as claimed in claim 9, comprising the heating control step of: