CN111442475A

CN111442475A - Defrosting control method and device of air conditioning system and air conditioner

Info

Publication number: CN111442475A
Application number: CN202010281551.5A
Authority: CN
Inventors: 高思云; 王晓鸾; 赵站稳
Original assignee: Hisense Shandong Air Conditioning Co Ltd
Current assignee: Hisense Air Conditioning Co Ltd
Priority date: 2020-04-10
Filing date: 2020-04-10
Publication date: 2020-07-24
Anticipated expiration: 2040-04-10
Also published as: CN111442475B

Abstract

The invention discloses a defrosting control method and a defrosting control device of an air conditioning system and an air conditioner, relates to the technical field of air conditioners, and is used for reducing the influence of the air conditioning system on the indoor environment temperature in the defrosting process and simultaneously shortening the defrosting time of the air conditioning system. The defrosting control method of the air conditioning system comprises the following steps: when the air-conditioning system meets the defrosting condition, controlling the air-conditioning system to defrost the indoor unit; acquiring the exhaust temperature of a compressor; the first adjusting step is performed according to the exhaust temperature. The defrosting control device of the air conditioning system comprises a processor and a communication interface. The air conditioner comprises an air conditioning system, a defrosting control device of the air conditioning system and a temperature sensor.

Description

Defrosting control method and device of air conditioning system and air conditioner

Technical Field

The invention relates to the technical field of air conditioners, in particular to a defrosting control method and a defrosting control device of an air conditioner system and an air conditioner.

Background

In order to meet the requirement of users on the heating comfort of the air conditioning system, at least one set of capillary tubes is generally added in the air conditioning system, so that the existing air conditioning system comprises an outdoor unit, at least one indoor unit and at least one set of capillary tubes. At the moment, the outdoor unit and the indoor unit are matched to refrigerate the indoor environment where the indoor unit is located; the outdoor unit is matched with the capillary tube to heat the indoor environment where the capillary tube is located. However, when the outdoor unit is combined with the capillary tube for heating, the surface temperature of the heat exchanger of the outdoor unit is low, and frost is formed on the surface of the heat exchanger of the outdoor unit. And as the heating of the air conditioning system is continuously performed, the frost layer on the surface of the heat exchanger of the outdoor unit is continuously thickened, so that the heating effect of the air conditioning system is deteriorated.

In order to ensure a better heating effect of the air conditioning system, the heat exchanger of the outdoor unit generally needs to be defrosted. In the prior art, the heat exchanger of the outdoor unit is defrosted mainly in a reverse defrosting mode, but when the capillary tube is matched with the outdoor unit for reverse defrosting, the indoor environment temperature where the capillary tube is located can be quickly reduced, and the defrosting process consumes a long time.

Disclosure of Invention

The invention aims to provide a defrosting control method and a defrosting control device of an air conditioning system and an air conditioner, which are used for reducing the influence of the air conditioning system on the indoor environment temperature in the defrosting process and simultaneously shortening the defrosting time of the air conditioning system.

In order to achieve the above object, the present invention provides a defrost control method of an air conditioning system. The defrosting control method of the air conditioning system is applied to the air conditioning system. The air conditioning system comprises an outdoor unit, at least one indoor unit and at least one group of capillary tubes. The outdoor unit comprises a compressor, a four-way reversing valve and a condenser.

And the first end of the four-way reversing valve is connected with the outlet of the compressor.

And the second end of the four-way reversing valve is connected with the first end of the condenser.

And the third end of the four-way reversing valve is respectively connected with the inlet of the compressor and the second end of each indoor unit in the at least one indoor unit.

And the fourth end of the four-way reversing valve is respectively connected with the first end of each group of capillary tubes in the at least one group of capillary tubes.

And the second end of the condenser is respectively connected with the first end of each indoor unit in the at least one indoor unit and the second end of each group of capillary tubes in the at least one group of capillary tubes.

And a first expansion valve is arranged between the second end of the condenser and the second end of the capillary tube, and a second expansion valve is arranged between the second end of the condenser and the first end of each indoor unit in the at least one indoor unit.

The defrosting control method of the air conditioning system comprises the following steps:

and when the air conditioning system meets the defrosting condition, carrying out defrosting operation on the indoor unit.

The indoor unit defrosting operation is as follows: controlling a fan of each indoor unit in the at least one indoor unit to be closed, controlling a first end of the four-way reversing valve to be communicated with a second end of the four-way reversing valve, controlling a third end of the four-way reversing valve to be communicated with a fourth end of the four-way reversing valve, controlling the first expansion valve to be in a closed state, and controlling the second expansion valve to be in an open state.

And acquiring the exhaust temperature of the compressor.

A first adjusting step is performed according to the exhaust temperature.

The first adjusting step is as follows: and when the exhaust temperature is higher than a first preset temperature, the opening degree of the second expansion valve is made to be a first preset opening degree.

And when the exhaust temperature is higher than a second preset temperature and lower than the first preset temperature, the opening degree of the second expansion valve is set to be a second preset opening degree.

And when the exhaust temperature is lower than the second preset temperature, the opening degree of the second expansion valve is set to be a third preset opening degree.

The first preset temperature is higher than the second preset temperature, and the first preset opening degree is higher than the second preset opening degree; the second preset opening degree is larger than the third preset opening degree.

Compared with the prior art, in the defrosting control method of the air conditioning system, when the air conditioning system meets the defrosting condition, the air conditioning system is controlled to defrost the indoor unit. At the moment, the first end of the four-way reversing valve is communicated with the second end of the four-way reversing valve, the third end of the four-way reversing valve is communicated with the fourth end of the four-way reversing valve, the first expansion valve is in a closed state, and the second expansion valve is in an open state, so that liquid refrigerant only circulates between the outdoor unit and the indoor unit and cannot enter the capillary tube, and the capillary tube is guaranteed against refrigeration. And the fan of the indoor unit is turned off, so that the liquid refrigerant only reduces the ambient temperature near the indoor unit when evaporating and absorbing heat, the indoor ambient temperature where the indoor unit is located cannot be greatly reduced, and the influence on the indoor ambient temperature in the defrosting process of the air conditioning system is reduced.

Meanwhile, when the exhaust temperature is higher than the first preset opening degree, the exhaust temperature of the compressor is higher, and the temperature difference between the high-pressure gaseous condensing agent discharged by the compressor and the frost layer on the surface of the heat exchanger of the indoor unit is larger. At this time, the heat exchange rate between the high-pressure gaseous refrigerant and the frost layer on the surface of the heat exchanger of the outdoor unit is high, so that the high-pressure gaseous refrigerant can be rapidly condensed in the heat exchanger of the indoor unit to release heat. When the opening degree of the second expansion valve is the first preset opening degree, the opening degree of the second expansion valve is larger, the flow speed of the high-pressure gaseous condensing agent in the heat exchanger of the outdoor unit is higher, and more heat generated by condensation of the high-pressure gaseous condensing agent in unit time can be generated, so that the defrosting efficiency of the air conditioning system can be improved, and meanwhile, the influence on the indoor environment temperature in the defrosting process of the air conditioning system is reduced.

When the temperature of the compressor is lower than the second preset temperature, the exhaust temperature of the compressor is lower, and the temperature difference between the high-pressure gaseous refrigerant discharged by the compressor and the frost layer on the surface of the heat exchanger of the outdoor unit is smaller, so that the heat exchange rate between the high-pressure gaseous refrigerant and the frost layer on the surface of the heat exchanger of the outdoor unit is slower. When the second expansion opening degree is the third preset opening degree, the flow speed of the high-pressure gaseous condensing agent with lower temperature in the heat exchanger of the outdoor unit is smaller, so that the high-pressure gaseous condensing agent can fully exchange heat with a frost layer on the surface of the heat exchanger of the indoor unit, the high-pressure gaseous condensing agent can be fully condensed to release heat, and the condensation efficiency of the high-pressure gaseous condensing agent is improved.

When the exhaust temperature of the compressor is higher than the second preset temperature and lower than the first preset temperature, the temperature of the high-pressure gaseous condensing agent discharged by the compressor is moderate. At this time, the opening degree of the second expansion valve is set to the second preset opening degree, so that the defrosting speed of the air conditioning system can be ensured, and the condensation efficiency of the high-pressure gas condensation can be ensured.

The invention also provides a defrosting control device of the air conditioning system, which is applied to the air conditioning system. The air conditioning system comprises an outdoor unit, at least one indoor unit and at least one group of capillary tubes. The outdoor unit comprises a compressor, a four-way reversing valve and a condenser.

The defrosting control device of the air conditioning system comprises:

a processor for controlling the fan in each of the at least one indoor unit to turn off. And controlling the first end of the four-way reversing valve to be communicated with the second end of the four-way reversing valve. And controlling the third end of the four-way reversing valve to be communicated with the fourth end of the four-way reversing valve. And controlling the first expansion valve to be in a closed state. And controlling the second expansion valve to be in an open state.

A communication interface for obtaining a discharge temperature of the compressor.

And when the exhaust temperature is higher than a first preset temperature, the processor is further used for enabling the opening degree of the second expansion valve to be a first preset opening degree.

And when the exhaust temperature is higher than a second preset temperature and lower than the first preset temperature, the processor is also used for enabling the opening degree of the second expansion valve to be a second preset opening degree.

And when the exhaust temperature is lower than the second preset temperature, the processor is further used for enabling the opening degree of the second expansion valve to be a third preset opening degree.

Wherein the first preset temperature is greater than the second preset temperature. The first preset opening degree is larger than the second preset opening degree; the second preset opening degree is larger than the third preset opening degree.

Compared with the prior art, the beneficial effects of the control device of the air conditioning system provided by the embodiment of the invention are the same as those of the control device of the air conditioning system, and the detailed description is omitted here.

The invention also provides an air conditioner. The air conditioner comprises the air conditioning system, the defrosting control device of the air conditioning system and a temperature sensor, wherein the temperature sensor is arranged at an exhaust port of the compressor.

Compared with the prior art, the beneficial effects of the air conditioning system provided by the invention are the same as those of the air conditioning system control device, and are not repeated herein.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and 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 and not to limit the invention. In the drawings:

FIG. 1 is a schematic diagram of a prior art air conditioning system;

FIG. 2 is a flow diagram of a condensing agent in a prior art air conditioning system for cooling;

FIG. 3 is a flow diagram of a condensing agent in an air conditioning system for heating in the prior art;

fig. 4 is a flowchart illustrating a control method of an air conditioning system according to an embodiment of the present invention;

fig. 5 is a second flowchart of a control method of an air conditioning system according to an embodiment of the present invention;

fig. 6 is a third flowchart of a control method of an air conditioning system according to an embodiment of the present invention;

fig. 7 is a fourth flowchart of a control method of an air conditioning system according to an embodiment of the present invention;

fig. 8 is a fifth flowchart of a control method of an air conditioning system according to an embodiment of the present invention;

fig. 9 is a sixth flowchart of a control method of an air conditioning system according to an embodiment of the present invention;

fig. 10 is a seventh flowchart of a control method of an air conditioning system according to an embodiment of the present invention;

fig. 11 is an eighth flowchart of a control method of an air conditioning system according to an embodiment of the present invention;

fig. 12 is a ninth flowchart of a control method of an air conditioning system according to an embodiment of the present invention;

fig. 13 is a tenth flowchart of a control method of an air conditioning system according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. 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 application.

In the description of the present application, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be construed as limiting the present application.

The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

In the description of the present application, "a plurality" means two or more unless otherwise specified. In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

The air conditioner comprises an outdoor unit and at least one indoor unit, and the outdoor unit and the indoor unit can refrigerate or heat an indoor space where the indoor unit is located when being used in a matched mode.

A refrigeration cycle when an outdoor unit and an indoor unit of an air conditioner are combined includes a series of processes involving compression, condensation, expansion, and evaporation, and supplies refrigerant to air that has been conditioned and heat-exchanged. In the refrigeration cycle, the heat exchanger in the outdoor unit functions as a condenser, and the heat exchanger in the indoor unit functions as an evaporator. At this time, the compressor compresses the gaseous refrigerant gas and discharges the compressed high-temperature high-pressure gaseous refrigerant. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor flows into the condenser. The condenser condenses the high temperature, high pressure gaseous refrigerant into a high pressure liquid refrigerant and heat is released to the surrounding environment during the condensation process. The expansion valve expands the high-pressure liquid refrigerant to convert it into a low-pressure liquid refrigerant. The evaporator evaporates the liquid refrigerant to form a low pressure gaseous refrigerant and returns the low pressure gaseous refrigerant to the compressor. The evaporator can achieve a refrigerating effect by heat-exchanging with a material to be cooled using latent heat of evaporation of a liquid refrigerant. The air conditioner can adjust the temperature of the indoor space throughout the cycle. In addition, in the process of refrigeration cycle, the refrigerant in the indoor unit can be evaporated quickly, so that the ambient temperature of the indoor space can be reduced quickly, and the comfort of the indoor space where a user is located is ensured.

Similarly, a heating cycle when an outdoor unit and an indoor unit of an air conditioner are combined includes a series of processes involving compression, evaporation, condensation, and expansion, and supplies gaseous refrigerant to air that has been conditioned and heat-exchanged. In the heating cycle, the heat exchanger in the outdoor unit functions as an evaporator, and the heat exchanger in the indoor unit functions as a refrigerant. At this time, the compressor compresses a liquid refrigerant and discharges the compressed high-pressure liquid refrigerant. The high-pressure liquid refrigerant discharged by the compressor is evaporated by the evaporator to form high-pressure gaseous refrigerant, and the high-pressure gaseous refrigerant is expanded into low-pressure gaseous refrigerant under the action of the expansion valve. The condenser condenses the low-pressure gaseous refrigerant into a low-pressure liquid refrigerant, and the released heat is transferred to the surrounding environment to heat the surrounding environment. Meanwhile, the low-pressure liquid refrigerant is condensed again by the condenser and then returns to the compressor.

In the entire heating cycle, the condenser can radiate heat to the surrounding environment by condensing the low-pressure liquid refrigerant, and thus can heat the indoor space. However, in the heating cycle, the efficiency of heating the indoor space by the heat released by condensation is poor, and it is difficult to satisfy the user's requirement for comfort of indoor temperature, and it is also necessary to heat the indoor space by using another indoor heating method.

At present, indoor heating modes mainly comprise centralized heating and household heating. The central heating refers to introducing hot water with higher temperature into a water heating system, so that the hot water can exchange heat with the indoor space, the indoor space can be heated, and the heating requirement of a user is met. However, when central heating is adopted, components such as a central pipe, a water collecting and distributing device, a water pipe, a valve and the like need to be installed, and equipment cost is high. In addition, the central heating only heats the indoor space, and cannot cool the indoor environment.

The household heating comprises gas furnace heating, water/ground source heat pump heating, air source heat pump heating, waterless floor heating and the like. The gas furnace heating mainly utilizes a gas heating water system to heat, and the cost is higher. Meanwhile, the gas furnace can not refrigerate the indoor environment for heating.

Although the used energy is free, the free energy cannot be continuously supplied, so that the water/ground source heat pump heating cannot be continuously performed. And the water/ground source heat pump heating system needs a large-scale water pump and secondary heat exchange equipment, so that the investment is high and the maintenance cost is high.

The air source heat pump heating mainly utilizes secondary heat exchange of refrigerant and air and water to heat the indoor space, so that energy cost can be saved, but the air source heat pump has low heat exchange efficiency and also has the risk of water leakage.

The waterless floor heating refers to that a copper capillary pipe coil with the outer diameter of 3-4 mm and the length of 10-20 m is paved on the ground in a multi-way parallel mode, and the paving method is the same as that of the existing water pipe of a water system. The copper capillary tube is connected with an air conditioner outdoor unit, the floor is heated through the refrigerant, floor radiation heating is realized, secondary heat exchange with a water system is omitted, heat exchange efficiency is improved, and meanwhile, the refrigerant system does not need later maintenance, is low in leakage rate, long in service life and the like; the refrigerant absorbs the heat of the external environment through evaporation and condensation, the energy efficiency is high, the later use and maintenance cost is greatly reduced, and the system is a technical revolution of the heating field.

Based on this, in order to satisfy the requirement of the user for the comfort of cooling and heating of the air conditioner, the air conditioning system can be improved, and referring to fig. 1, the improved air conditioning system comprises: an outdoor unit 100, at least one indoor unit 200 (only one shown), and at least one capillary tube 300 (only one shown); the outdoor unit 100 includes a compressor 110, a four-way reversing valve 120, and a condenser 130.

A first end of the four-way reversing valve 120 is connected to an outlet of the compressor 110.

The second end of the four-way reversing valve 120 is connected to a first end of a condenser 130.

The third end of the four-way reversing valve 120 is connected to the inlet of the compressor 110 and the second end of the indoor unit 200, respectively.

The fourth end of the four-way reversing valve 120 is connected to the first end of the capillary tube 300.

The second end of the condenser 130 is connected to the first end of the indoor unit 200 and the second end of the capillary tube 300, respectively.

A first expansion valve 140 is disposed between the second end of the condenser 130 and the second end of the capillary tube 300, and a second expansion valve 150 is disposed between the second end of the condenser 130 and the first end of each indoor unit 200 of the at least one indoor unit 200.

At this time, referring to fig. 2, when it is required to cool the indoor space, the first end of the four-way selector valve 120 is controlled to communicate with the second end of the four-way selector valve 120, and the second expansion valve 150 is controlled to be in an open state. At this time, the air conditioning system controls the compressor 110 of the outdoor unit 100 to perform a cooling operation, such that the flow direction of the high-pressure gaseous refrigerant discharged from the first end of the compressor is as shown in fig. 2 (the solid arrow in fig. 2 indicates the flow direction of the refrigerant), the high-pressure gaseous refrigerant passes through the heat exchanger of the outdoor unit and is condensed into a high-pressure liquid refrigerant, and then the high-pressure liquid refrigerant passes through the condenser 130 and is sufficiently condensed, and then enters the indoor unit 200, and evaporation heat exchange is performed in the indoor unit 200, thereby cooling the indoor unit 200.

Specifically, the four-way selector valve 120 is controlled to be de-energized, such that the first end of the four-way selector valve 120 is communicated with the second end of the four-way selector valve 120. The air conditioning system controls the operation of the compressor 110 such that the first end of the compressor 110 discharges high-pressure gaseous refrigerant. The high-pressure gaseous refrigerant passes through the first end of the four-way reversing valve 120 and the second end of the four-way reversing valve 120, enters the condenser 130, and is liquefied to become a high-pressure liquid refrigerant. The high-pressure liquid refrigerant flows into the indoor unit 200 in the on state, absorbs heat through evaporation, and becomes a gaseous refrigerant, thereby reducing the indoor temperature. The gaseous refrigerant can also return to the inlet of the compressor 110 from the second end of the indoor unit 200 in the on state through the low pressure valve, forming a refrigeration cycle.

Referring to fig. 3, when it is required to heat the indoor space, the first end of the four-way reversing valve 120 is made to communicate with the fourth end of the four-way reversing valve 120. The air conditioning system controls the first expansion valve 140 to be in an open state and controls the second expansion valve 150 to be in a closed state. In this way, when the compressor 110 in the indoor unit 200 is operated, the flow path of the high-pressure liquid refrigerant discharged from the first end of the compressor is as shown in fig. 3 (the dotted arrow in fig. 3 indicates the flow direction of the refrigerant), and the high-pressure liquid refrigerant enters the capillary tube 300 from the first end of the capillary tube 300, and is condensed and heat-exchanged in the capillary tube 300, thereby achieving radiation heating of the indoor air.

Specifically, the four-way selector valve 120 is controlled to be powered on, such that the first end of the four-way selector valve 120 is communicated with the fourth end of the four-way selector valve 120. The high-pressure gaseous refrigerant discharged from the first end of the compressor 110 is condensed in the capillary tube 300 to release heat, thereby heating the room by heat radiation. The condensed liquid refrigerant flows out of the second end of the capillary tube 300, enters the condenser 130, and is evaporated to absorb heat, thereby becoming a gaseous refrigerant. The gaseous refrigerant is returned to the inlet of the compressor 110 through the second and third ends of the four-way reversing valve 120, thereby forming a heating cycle. As can be seen from the above, in the air conditioning system, when the outdoor unit 100 is engaged with the indoor unit 200, the requirement of the user for the cooling comfort of the air conditioner can be satisfied, and when the outdoor unit 100 is engaged with the capillary tube 300, the requirement of the user for the heating comfort of the air conditioner can be satisfied.

However, in the process of condensing and heating the indoor space in the air conditioning system, the temperature of the surface of the heat exchanger in the outdoor unit 100 is low, and thus a frost layer is formed on the surface of the heat exchanger. And as the heating is continuously performed, the frost layer on the surface of the heat exchanger is continuously thickened, so that the heating effect of the air conditioning system is deteriorated.

In order to ensure the heating effect of the air conditioning system, the heat exchanger generally needs to be defrosted. In the prior art, the heat exchanger is mainly defrosted in a reverse defrosting mode, but when an air conditioning system with the capillary tube 300 added performs reverse defrosting, the ambient temperature of the indoor space where the capillary tube 300 is located is rapidly reduced, and the defrosting process consumes a long time.

In order to reduce the influence of the defrosting process of the air conditioning system on the environment temperature of the indoor space and shorten the defrosting time of the air conditioning system, the embodiment of the invention provides a defrosting control method of the air conditioning system. Referring to fig. 4 and 5, the defrosting control method of the air conditioning system includes:

step S400: and carrying out defrosting operation of the indoor unit.

Wherein, indoor set defrosting operation includes: the method includes controlling a fan in each indoor unit 200 of the at least one indoor unit 200 to be turned off, controlling a first end of the four-way reversing valve 120 to be communicated with a second end of the four-way reversing valve 120, controlling a third end of the four-way reversing valve 120 to be communicated with a fourth end of the four-way reversing valve 120, controlling the first expansion valve 140 to be in a closed state, and controlling the second expansion valve 150 to be in an open state, so that a condensing agent discharged from the compressor 110 can circulate between the outdoor unit 100 and the indoor units 200.

Step S500: the discharge temperature of the compressor 110 is acquired. The source of the discharge temperature of the compressor 110 is various. For example: a temperature sensing assembly is employed to sense the discharge temperature of the compressor 110.

Step S600: performing a first adjustment step according to the exhaust temperature;

the first adjusting step is as follows: when the exhaust temperature is greater than the first preset temperature, the opening degree of the second expansion valve 150 is made the first preset opening degree. It should be understood that the above-mentioned making the opening degree of the second expansion valve 150 the first preset opening degree means that the opening degree of the second expansion valve 150 is controlled to be constant if the opening degree of the second expansion valve 150 is equal to the first preset opening degree at present; if the opening degree of the second expansion valve 150 is not equal to the first preset opening degree, the opening degree of the second expansion valve 150 is controlled to be adjusted to the first preset opening degree. It should be noted that the first preset temperature may be selected according to actual conditions, as long as the temperature difference between the first preset temperature and the temperature of the frost layer on the surface of the heat exchanger of the outdoor unit 100 can rapidly condense the high-pressure gaseous refrigerant discharged from the compressor 110. For example: the first preset temperature may be 70 to 85 ℃. The first preset opening degree can also be selected according to actual conditions, and the air conditioning system can have a higher defrosting speed as long as the flow speed of the high-pressure gaseous refrigerant can be increased.

When the exhaust temperature is higher than the second preset temperature and lower than the first preset temperature, the initial opening degree of the second expansion valve 150 is set to the second preset opening degree. It should be understood that the above-mentioned making the opening degree of the second expansion valve 150 the second preset opening degree means that the opening degree of the second expansion valve 150 is controlled to be constant if the opening degree of the second expansion valve 150 is equal to the second preset opening degree at present; if the current opening degree of the second expansion valve 150 is not equal to the second preset opening degree, controlling the opening degree of the second expansion valve 150 to be adjusted to the second preset opening degree. It should be noted that the second preset temperature may be selected according to actual conditions, as long as the difference between the second preset temperature and the frost layer on the surface of the heat exchanger of the outdoor unit 100 is small. For example, the second predetermined temperature may be 30 to 50 ℃. The second preset opening degree can also be selected according to actual conditions, as long as the high-pressure gaseous condensing agent with moderate temperature can be fully condensed, and the air-conditioning system has good defrosting speed.

When the discharge temperature of the compressor 110 is less than the second preset temperature, the opening degree of the second expansion valve 150 is made a third preset opening degree. It should be understood that the above-mentioned making the opening degree of the second expansion valve 150 the third preset opening degree means that the opening degree of the second expansion valve 150 is controlled to be unchanged if the opening degree of the second expansion valve 150 is currently equal to the third preset opening degree; if the opening degree of the second expansion valve 150 is not equal to the third preset opening degree, the opening degree of the second expansion valve 150 is controlled to be adjusted to the third preset opening degree. It should be noted that the preset opening degree needs to be selected according to actual conditions, as long as sufficient condensation of the high-pressure gaseous refrigerant with a low temperature can be ensured.

The first preset temperature is higher than the second preset temperature, and the first preset opening is larger than the second preset opening; the second predetermined opening degree is greater than the third predetermined opening degree, and at this time, when the discharge temperature of the compressor 110 is high, the opening degree of the second expansion valve 150 is high, and when the discharge temperature of the compressor 110 is low, the opening degree of the second expansion valve 150 is low.

In the defrosting control method of the air conditioning system provided by the embodiment of the invention, the air conditioning system is controlled to execute the defrosting action of the indoor unit, so that the first end of the four-way reversing valve 120 is communicated with the second end of the four-way reversing valve 120, the third end of the four-way reversing valve 120 is communicated with the fourth end of the four-way reversing valve 120, the first expansion valve 140 is in a closed state, and the second expansion valve 150 is in an open state, so that the liquid refrigerant only circulates between the outdoor unit 100 and the indoor unit 200 and cannot enter the capillary tube 300, and the refrigeration phenomenon of the capillary tube 300 cannot occur. And the fan in the indoor unit 200 is turned off, so that the liquid refrigerant only reduces the ambient temperature near the indoor unit 200 when evaporating and absorbing heat, the indoor ambient temperature is not greatly reduced, and the influence of defrosting of the air conditioning system on the indoor ambient temperature is reduced.

Meanwhile, when the discharge temperature is greater than the first preset opening degree, it means that the discharge temperature of the compressor 110 is high, and the temperature difference between the high-pressure gaseous refrigerant discharged from the compressor 110 and the frost layer on the heat exchanger surface of the indoor unit 200 is large. At this time, the heat exchange rate of the high-pressure gaseous refrigerant with the frost layer on the surface of the heat exchanger of the outdoor unit 100 is fast, so that the high-pressure gaseous refrigerant can be rapidly condensed in the heat exchanger of the indoor unit 200 to release heat. When the opening degree of the second expansion valve 150 is the first preset opening degree, the opening degree of the second expansion valve 150 is larger, so that the flow rate of the high-pressure gaseous refrigerant in the heat exchanger of the outdoor unit 100 is faster, and more heat generated by condensation of the high-pressure gaseous refrigerant in unit time can be generated, thereby improving the defrosting efficiency of the air conditioning system and reducing the influence on the indoor environment temperature when the air conditioning system is defrosted.

When the temperature of the compressor 110 is less than the second preset temperature, which indicates that the discharge temperature of the compressor 110 is low, the temperature difference between the high-pressure gaseous refrigerant discharged from the compressor 110 and the frost layer on the heat exchanger surface of the outdoor unit 100 is large, so that the heat exchange rate between the high-pressure gaseous refrigerant and the frost layer on the heat exchanger surface of the outdoor unit 100 is slow. When the second expansion opening is the third preset opening, the flow velocity of the high-pressure gaseous refrigerant in the heat exchanger of the outdoor unit 100 is low, so that the high-pressure gaseous refrigerant can exchange heat with the frost layer on the surface of the heat exchanger of the indoor unit 200 sufficiently, the high-pressure gaseous refrigerant can be condensed sufficiently to release heat, and the condensation efficiency of the high-pressure gaseous refrigerant is improved.

When the discharge temperature of the compressor 110 is greater than the second preset temperature and the discharge temperature of the compressor 110 is less than the first preset temperature, the temperature of the high-pressure gaseous refrigerant discharged from the compressor 110 is moderate. At this time, the opening degree of the second expansion valve 150 is set to a second preset opening degree that is moderate, so that the defrosting speed of the air conditioner can be ensured, and the condensing efficiency of the high-pressure gas condensation can be ensured.

As a possible implementation manner, the first preset opening degree, the second preset opening degree and the third preset opening degree are all according to the formula O ═ O' K₁Thus obtaining the product. Wherein O' represents an initial opening degree of the second expansion valve 150, K₁An opening degree coefficient indicating an opening degree of the second expansion valve 150, and an opening degree coefficient of the first preset opening degree being a first preset opening degree coefficient value; the opening coefficient of the second preset opening is a second preset opening coefficient value; the opening coefficient of the third preset opening is a third preset opening coefficient value; the first preset opening coefficient value is greater than the second preset opening coefficient value, the second preset opening coefficient value is greater than the third preset opening coefficient value, and the third preset opening coefficient value is greater than zero.

At this time, in the above-mentioned defrosting control method of the air conditioning system, the opening coefficient of the second expansion valve 150 is determined according to the temperature range in which the discharge temperature of the compressor 110 is located, and then the opening degree of the second expansion valve 150 is adjusted according to the initial opening degree of the compressor 110 and the opening coefficient of the second expansion valve 150, at this time, the preset opening degree of the second expansion valve 150 and the opening degree of the second expansion valve 150 have a linear relationship, and when the discharge temperature of the compressor 110 is higher, the opening coefficient of the second expansion valve 150 is also higher, so that the obtained first preset opening degree of the second expansion valve 150 is also higher, and when the discharge temperature of the compressor 110 is moderate, the opening coefficient of the second expansion valve 150 is also moderate, so that the obtained third preset opening degree of the second expansion valve 150 is also moderate.

Specifically, the first preset opening coefficient value is 1.3-1.5, and at this time, the obtained first preset opening is larger than the initial opening of the second expansion valve 150, so that the defrosting efficiency of the air conditioning system is ensured.

The second preset opening coefficient value is 1-1.2, and at the moment, the obtained second preset opening is basically the same as the initial opening of the second expansion valve 150, so that the defrosting efficiency of the air conditioning system can be ensured, and meanwhile, the utilization rate of the high-pressure gaseous refrigerant can be ensured.

The coefficient value of the third preset opening degree is 0.5-0.8, and at the moment, the obtained third preset opening degree is smaller than the initial opening degree of the second expansion valve 150, so that the refrigerant is fully condensed and releases heat, and the utilization rate of the high-pressure gaseous refrigerant is ensured.

Exemplarily, the defrosting control method of the air conditioning system further includes:

and (3) circulating step: and returning to the step of acquiring the exhaust temperature of the compressor 110 at intervals of a first preset time. It should be understood that, at this time, the discharge temperature of the compressor 110 is periodically received, and the receiving period is a first preset time period. The first preset time may be selected according to actual conditions, and for example, the first preset time is 60s to 120 s.

At this time, the exhaust temperature of the compressor 110 may be obtained in real time along with the progress of the defrosting operation, and then the opening degree of the second expansion valve 150 may be dynamically adjusted according to the exhaust temperature of the compressor 110, so that the opening degree of the second expansion valve 150 in the defrosting process may be ensured to be adapted to the exhaust temperature of the compressor, and the defrosting efficiency of the air conditioning system may be improved.

Specifically, referring to fig. 6, the adjusting the opening degree of the second expansion valve 150 further includes:

step S100: the cumulative length of time that the second expansion valve 150 is in the open state is recorded.

Step S200: and comparing the accumulated time length with a second preset time length. It should be understood that the second preset time period is a fixed time period preset in the air conditioning system. The second preset time period can be selected according to actual conditions. For example, the second preset time period may be 40s to 120 s.

If the accumulated time length is less than the second preset time length, executing step S600: the first adjusting step is performed according to the exhaust temperature.

If the accumulated time length is greater than or equal to the second preset time length, executing step S700: the second adjusting step is performed according to the exhaust temperature.

Wherein, referring to fig. 7, the second adjusting step includes:

step S710: comparing the current exhaust temperature with the last exhaust temperature;

if the current exhaust temperature is equal to the last exhaust temperature, go to step S720: the opening degree of the second expansion valve 150 is kept constant.

If the current exhaust temperature is not equal to the last exhaust temperature, step S730 is executed: the opening degree of the second expansion valve is adjusted according to the current exhaust temperature and the last opening degree coefficient.

When the discharge temperature is equal to the last discharge temperature, it means that the temperature difference between the high-pressure gaseous refrigerant introduced into the heat exchanger of the outdoor unit and the frost layer on the surface of the heat exchanger of the outdoor unit is not changed. At this time, as long as the opening degree of the second expansion valve is kept unchanged, the high-pressure gaseous refrigerant can be fully condensed, so that the air conditioning system has better defrosting efficiency.

When the exhaust temperature changes, the temperature difference between the high-pressure gaseous refrigerant entering the heat exchanger of the outdoor unit and the frost layer on the surface of the heat exchanger of the outdoor unit changes, so that the heat exchange rate between the high-pressure gaseous refrigerant and the frost layer is changed, the opening degree of the second expansion valve needs to be adjusted according to the current opening degree of the second expansion valve and the current exhaust temperature, the flow rate of the high-pressure gaseous refrigerant in the heat exchanger of the outdoor unit is matched with the condensation rate of the high-pressure gaseous refrigerant, and the air conditioning system has high defrosting efficiency while the high-pressure gaseous refrigerant is fully condensed.

Wherein, referring to fig. 8, adjusting the opening degree of the second expansion valve 150 includes:

step S731: obtaining the opening coefficient K of the last time₁；

If the opening coefficient K of the last time₁And when the current exhaust temperature is lower than the third preset temperature, the difference between the temperature of the high-pressure gaseous condensing agent in the heat exchanger of the outdoor unit and the temperature of the frost layer on the surface of the heat exchanger is reduced, and the condensing speed of the high-pressure gaseous condensing agent is reduced. At this time, in order to ensure that the high-pressure gaseous refrigerant can be sufficiently condensed, step S732A is performed: the opening degree of the second expansion valve 150 is reduced to a second preset opening degree value.

If the opening coefficient K of the last time₁And the difference value is a second preset opening coefficient value, and when the exhaust temperature is higher than the first preset temperature, the difference value between the temperature of the high-pressure gaseous condensing agent in the heat exchanger of the outdoor unit and the temperature of the frost layer on the surface of the heat exchanger is increased, and the condensation rate of the high-pressure gaseous condensing agent is increased. At this time, in order to increase the defrosting rate of the air conditioning system and shorten the defrosting time of the air conditioning system, step S732B is executed: the opening degree of the second expansion valve 150 is increased to a first preset opening degree.

If the opening coefficient K of the last time₁And the current exhaust temperature is smaller than the second preset temperature, which shows that the difference between the temperature of the high-pressure gaseous refrigerant in the heat exchanger of the outdoor unit and the temperature of the frost layer on the surface of the heat exchanger is reduced, and the condensing speed of the high-pressure gaseous refrigerant is reduced. At this time, in order to ensure that the high-pressure gaseous refrigerant can be sufficiently condensed, step S732C is performed: reducing the opening degree of the second expansion valve 150 to a third preset opening degree;

if the opening coefficient K of the last time₁And the current exhaust temperature is greater than the third preset temperature, which indicates that the difference between the temperature of the high-pressure gaseous condensing agent in the heat exchanger of the outdoor unit and the temperature of the frost layer on the surface of the heat exchanger is increased, and the condensation rate of the high-pressure gaseous condensing agent is increased. At this time, in order to increase the defrosting rate of the air conditioning system, the air conditioning system is condensedShort defrosting time of the air conditioning system, step S732D is executed: increasing the opening degree of the second expansion valve 150 to a second preset opening degree;

otherwise, it indicates that the change value of the discharge temperature is small and the condensation rate of the refrigerant in the heat exchanger of the outdoor unit does not change much, and then the step S732E is executed: the opening degree of the second expansion valve 150 is kept constant.

As a possible implementation manner, referring to fig. 9, the initial opening degree of the second expansion valve 150 is obtained according to the following steps:

according to the caliber D of the second expansion valve and the rated refrigerating capacity Mo of the heat exchanger of the indoor unit_{Inner part}Determining the opening C to be corrected of the second expansion valve:

wherein, the opening C to be corrected is counted by steps; rated refrigerating capacity Mo of heat exchanger of indoor unit_{Inner part}Calculated as 100W; the caliber D of the second expansion valve is measured in mm;

according to rated refrigerating capacity Mo of heat exchanger of outdoor unit_{Outer cover}And the opening C to be corrected obtains the initial opening O' of the second expansion valve:

wherein, the rated refrigerating capacity Mo of the heat exchanger of the indoor unit_{Outer cover}Calculated as 100 w.

In the control method of the air conditioning system, the opening degree to be corrected of the second expansion valve is obtained according to the rated refrigerating capacity of the heat exchanger of the indoor unit and the caliber of the second expansion valve, so that when the second expansion valve is opened to the opening degree to be corrected, the flow rate of the condensing agent is matched with the caliber of the second expansion valve and the heat exchange capacity of the heat exchanger of the indoor unit. And then correcting the opening degree to be corrected by using the rated refrigerating capacity of the heat exchanger of the outdoor unit to obtain the initial opening degree of the second expansion valve. At this time, when the second expansion valve is opened to the opening to be corrected, the flow rate of the refrigerant is adapted to the aperture of the second expansion valve, the heat exchange capacity of the heat exchanger of the indoor unit, and the heat exchange capacity of the heat exchanger of the outdoor unit.

As one possible implementation manner, referring to fig. 10, before controlling the air conditioning system to perform an indoor unit defrosting operation, the control method of the air conditioning system further includes:

step S800: and judging whether the air conditioning system meets the defrosting condition or not.

When the air conditioning system meets the defrosting condition, executing the step S400: and controlling the air conditioning system to perform defrosting operation of the indoor unit.

When the air conditioning system does not meet the defrosting condition, returning to the step S800: and judging whether the air conditioning system meets the defrosting condition.

At the moment, whether the air-conditioning system meets the defrosting condition can be continuously judged, so that the defrosting action can be quickly executed when the air-conditioning system meets the defrosting condition, and the timeliness of defrosting is ensured. Specifically, the defrosting condition may be determined according to an operating environment of the air conditioning system, for example:

the accumulated heating time of the compressor 110 is more than or equal to 30-10 min, and the continuous heating time of the compressor 110 is more than 5 min; meanwhile, the outdoor environment temperature is more than 1-6 ℃, the condensing temperature of the condenser 130 is less than-3 ℃, and the duration of the condensing temperature of the condenser 130 being less than-3 ℃ reaches 3-5 min, so that the condition that the air conditioning system meets the defrosting condition can be judged.

Or, the accumulated heating time of the compressor is more than or equal to 30 min-10 min, and the continuous heating time of the compressor 110 is more than 5 min; meanwhile, the outdoor environment temperature is more than 1-6 ℃, the temperature difference between the outdoor environment temperature and the condensing temperature of the condenser 130 is more than 5-12 ℃, and the time for the outdoor environment temperature to be more than 5-12 ℃ and the condensing temperature of the condenser 130 to last for 3-5 min; the air conditioning system can be judged to meet the defrosting condition.

Or, the accumulated heating time of the compressor 110 is greater than or equal to 30min to 10min, and the continuous heating time of the compressor 110 is greater than 5 min; the condensing temperature of the condenser 130 is less than minus 11 ℃ to minus 13 ℃, and the duration of the condensing temperature of the condenser 130 is less than minus 11 ℃ to minus 13 ℃ for 3h to 9h, so that the condition that the air conditioning system meets the defrosting condition can be judged.

As a possible implementation manner, referring to fig. 11, after the air conditioning system satisfies the defrosting condition, before controlling the air conditioning system to perform the defrosting operation of the indoor unit, the defrosting control method of the air conditioning system further includes:

step S900: judging whether the indoor unit 200 is connected to the outdoor unit 100;

if the indoor unit 200 is connected to the outdoor unit 100, the process proceeds to step S400: controlling an air conditioning system to perform indoor unit defrosting operation;

if the indoor unit 200 is not connected to the outdoor unit 100, step S300 is performed: and controlling the air conditioning system to perform capillary defrosting operation.

The capillary defrosting operation includes: the first end of the control four-way reversing valve 120 is connected with the second end of the four-way reversing valve 120, the third end of the control four-way reversing valve 120 is communicated with the fourth end of the four-way reversing valve 120, the first expansion valve 140 is controlled to be in an open state, and the second expansion valve 150 is controlled to be in a closed state.

At this time, when the indoor unit 200 is connected to the outdoor unit 100, the indoor unit 200 is used to perform a defrosting operation in cooperation with the outdoor unit 100, so that the amount of cold generated in the indoor space during the defrosting operation can be reduced. When the indoor unit 200 is not connected to the outdoor unit 100, the capillary tube 300 is used to cooperate with the outdoor unit 100 to perform a defrosting operation, thereby ensuring the normal operation of the defrosting operation.

Specifically, whether the outdoor unit 100 is connected to the indoor unit 200 may be determined by various methods. For example:

before the defrosting operation is performed, the outdoor unit 100 is turned on after cooling and has no malfunction.

Example two

The embodiment of the invention provides a defrosting control device of an air conditioning system. The defrosting control device of the air conditioning system is used for the air conditioning system. Referring to fig. 1, the air conditioning system includes: comprises an outdoor unit 100, at least one indoor unit 200 and at least one group of capillary tubes 300; the outdoor unit 100 includes a compressor 110, a four-way reversing valve 120, and a condenser 130;

the first end of the four-way reversing valve 120 is connected with the outlet of the compressor 110;

the second end of the four-way reversing valve 120 is connected with the first end of the condenser 130;

the third end of the four-way reversing valve 120 is respectively connected with the inlet of the compressor 110 and the second end of each indoor unit 200 in the at least one indoor unit 200;

the fourth end of the four-way reversing valve 120 is respectively connected with the first end of each group of capillary tubes 300 in at least one group of capillary tubes 300;

the second end of the condenser 130 is respectively connected with the first end of each indoor unit 200 of the at least one indoor unit 200 and the second end of each group of capillary tubes 300 of the at least one group of capillary tubes 300;

Referring to fig. 12, the defrosting control apparatus of the air conditioning system includes:

and a processor 400, wherein the processor 400 is configured to control a fan in each indoor unit 200 of the at least one indoor unit 200 to be turned off. The first end of the control four-way reversing valve 120 communicates with the second end of the four-way reversing valve 120. The third end of the control four-way reversing valve 120 communicates with the fourth end of the four-way reversing valve 120. The first expansion valve 140 is controlled to be in a closed state. The second expansion valve 150 is controlled to be in an open state.

A communication interface 500, the communication interface 500 being configured to obtain a discharge temperature of the compressor 110;

the processor 400 is further configured to make the opening degree of the second expansion valve 150 a first preset opening degree when the exhaust temperature is greater than the first preset temperature.

When the exhaust temperature is higher than the second preset temperature and lower than the first preset temperature, the processor 400 is further configured to set the initial opening degree of the second expansion valve 150 to the second preset opening degree.

The processor 400 is further configured to make the opening degree of the second expansion valve 150 a third preset opening degree when the exhaust temperature is less than the second preset temperature.

The first preset temperature is higher than the second preset temperature, and the first preset opening degree is larger than the second preset opening degree; the second preset opening degree is larger than the third preset opening degree.

Illustratively, the processor 400 is further configured to determine the formula O ═ O' K₁And obtaining a first preset opening degree, a second preset opening degree and a third preset opening degree.

Specifically, the processor 400 is further configured to record an accumulated time period during which the second expansion valve 150 is in the open state.

The processor 400 is further configured to compare the accumulated time duration with a second preset time duration;

the processor 400 is further configured to perform a first adjusting step according to the exhaust temperature when the accumulated time period is less than a second preset time period.

The processor 400 is further configured to perform a second adjustment step based on the exhaust temperature when the accumulated time period is greater than or equal to a second predetermined time period.

In the second adjustment step, the processor 400 is further configured to compare the current exhaust temperature with the last exhaust temperature;

if the current exhaust temperature is the same as the last exhaust temperature, the processor 400 is further configured to keep the opening degree of the second expansion valve 150 unchanged;

if the current exhaust temperature is different from the previous exhaust temperature, the processor 400 is further configured to obtain the opening coefficient K of the previous time₁；

If the opening coefficient K of the last time₁The first preset opening degree coefficient value, and when the current exhaust temperature is lower than the third preset temperature, the processor 400 is further configured to decrease the opening degree of the second expansion valve 150 to a second preset opening degree value.

If the opening coefficient K of the last time₁The processor 400 is further configured to increase the opening degree of the second expansion valve 150 to the first preset opening degree, where the second preset opening degree coefficient value is set, and the current exhaust temperature is greater than the first preset temperature.

If the opening coefficient K of the last time₁The processor 400 is further configured to decrease the opening degree of the second expansion valve 150 to a third preset opening degree, where the second preset opening degree coefficient value is set and the current exhaust temperature is lower than the second preset temperature.

If the opening coefficient K of the last time₁The processor 400 is further configured to increase the opening degree of the second expansion valve 150 to a second preset opening degree, where the third preset opening degree coefficient value is equal to or greater than the third preset temperature and the current exhaust temperature is greater than the third preset temperature.

The processor 400 is further configured to maintain the opening degree of the second expansion valve 150 unchanged.

Specifically, the processor 400 is further configured to determine the caliber D of the second expansion valve and the rated cooling capacity Mo of the heat exchanger of the indoor unit_{Inner part}Determining the opening C to be corrected of the second expansion valve:

wherein, the opening C to be corrected is counted by steps; rated refrigerating capacity Mo of heat exchanger of indoor unit_{Inner part}Calculated as 100W; the caliber D of the second expansion valve is measured in mm.

The processor 400 is also used for controlling the cooling capacity Mo of the heat exchanger of the outdoor unit according to the rated cooling capacity Mo_{Outer cover}And the opening C to be corrected obtains the initial opening O' of the second expansion valve:

As an embodiment, before controlling the air conditioning system to perform the indoor unit defrosting operation, the processor 400 is further configured to determine whether the air conditioning system meets a defrosting condition;

when the air conditioning system meets the defrosting condition, the processor 400 is further configured to control the air conditioning system to perform a defrosting operation;

when the air conditioning system does not satisfy the defrosting condition, the processor 400 is further configured to return to the step of determining whether the air conditioning system satisfies the defrosting condition.

EXAMPLE III

The embodiment of the invention provides an air conditioner. The air conditioner includes an air conditioning system, a defrost control device of the air conditioning system, and a temperature sensor, and the temperature sensor is provided at an exhaust port of the compressor 110.

Example four

Referring to fig. 13, an embodiment of the present invention further provides an air conditioner control terminal 600. The multi-connected air conditioner control terminal comprises a processor 620, a memory 630, a receiver 610, a transmitter 640 and a bus 650; the processor 620, the memory 630, and the receiver 610 and transmitter 640 communicate with each other through a bus 650. The memory 630 is used for storing computer instructions, and the processor 620 is used for executing the computer instructions to execute the multi-connected air conditioner control method.

The processor 620 in the embodiment of the present invention may be a single processor, or may be a general term for multiple processing elements. For example, the processor 620 may be a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), or one or more Integrated circuits configured to implement embodiments of the present invention. For example: one or more microprocessors (digital signal processors, DSP for short), or one or more Field Programmable gate arrays (FPGA for short).

The memory 630 may be a storage device or a combination of storage elements, and is used for storing executable program codes and the like. And the memory 630 may include a Random Access Memory (RAM) or a non-volatile memory (non-volatile memory), such as a magnetic disk memory, a Flash memory (Flash), and the like.

The bus 650 may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended ISA (EISA) bus, or the like. The bus 650 may be divided into an address bus, a data bus, a control bus, and the like. Fig. 13 is represented by a single thick line for ease of illustration, but does not represent only one bus 650 or one type of bus 650.

In the foregoing description of embodiments, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A defrosting control method of an air conditioning system is applied to the air conditioning system and is characterized in that the air conditioning system comprises an outdoor unit, at least one indoor unit and at least one group of capillary tubes; the outdoor unit comprises a compressor, a four-way reversing valve and a condenser;

the first end of the four-way reversing valve is connected with the outlet of the compressor;

the second end of the four-way reversing valve is connected with the first end of the condenser;

the third end of the four-way reversing valve is respectively connected with the inlet of the compressor and the second end of each indoor unit in the at least one indoor unit;

the fourth end of the four-way reversing valve is respectively connected with the first end of each group of capillary tubes in the at least one group of capillary tubes;

the second end of the condenser is respectively connected with the first end of each indoor unit in the at least one indoor unit and the second end of each group of capillary tubes in the at least one group of capillary tubes;

a first expansion valve is arranged between the second end of the condenser and the second end of the capillary tube, and a second expansion valve is arranged between the second end of the condenser and the first end of each indoor unit in the at least one indoor unit;

the defrosting method of the air conditioning system comprises the following steps:

carrying out defrosting operation on the indoor unit;

the indoor unit defrosting operation is as follows: controlling a fan of each indoor unit in the at least one indoor unit to be closed, controlling a first end of the four-way reversing valve to be communicated with a second end of the four-way reversing valve, controlling a third end of the four-way reversing valve to be communicated with a fourth end of the four-way reversing valve, controlling the first expansion valve to be in a closed state, and controlling the second expansion valve to be in an open state;

acquiring the exhaust temperature of the compressor;

performing a first adjustment step according to the exhaust temperature;

the first adjusting step is as follows:

when the exhaust temperature is higher than a first preset temperature, the opening degree of the second expansion valve is made to be a first preset opening degree;

when the exhaust temperature is higher than a second preset temperature and lower than the first preset temperature, the opening degree of the second expansion valve is set to be a second preset opening degree;

when the exhaust temperature is lower than the second preset temperature, the opening degree of the second expansion valve is set to be a third preset opening degree;

2. The defrosting control method of an air conditioning system according to claim 1, wherein the first preset opening degree, the second preset opening degree, and the third preset opening degree are all according to the formula O ═ O' K₁Where O' represents an initial opening degree of the second expansion valve, K₁An opening degree coefficient representing an opening degree of the second expansion valve, and the opening degree coefficient of the first preset opening degree being a first preset opening degree coefficient value; the opening coefficient of the second preset opening is a second preset opening coefficient value, and the opening coefficient of the third preset opening is a third preset opening coefficient value; the first preset opening coefficient value is greater than the second preset opening coefficient value, the second preset opening coefficient value is greater than the third preset opening coefficient value, and the third preset opening coefficient value is greater than zero.

3. The defrost control method of an air conditioning system of claim 2, further comprising:

and (3) circulating step: and returning to the step of acquiring the exhaust temperature of the compressor at intervals of a first preset time.

4. The defrost control method of an air conditioning system of claim 3, further comprising:

recording the accumulated time length of the second expansion valve in an opening state;

comparing the accumulated time length with a second preset time length;

if the accumulated time length is less than the second preset time length, executing a first adjusting step according to the exhaust temperature;

if the accumulated time length is greater than or equal to the second preset time length, performing a second adjusting step according to the exhaust temperature;

the second adjusting step is as follows:

comparing the current exhaust temperature with the last exhaust temperature;

if the current exhaust temperature is the same as the last exhaust temperature, keeping the opening degree of the second expansion valve unchanged;

and if the current exhaust temperature is different from the last exhaust temperature, adjusting the opening degree of the second expansion valve according to the current exhaust temperature and the last opening degree coefficient.

5. The defrost control method of an air conditioning system of claim 4, wherein said adjusting the opening degree of the second expansion valve according to the current discharge temperature and the opening degree coefficient of the last time comprises:

obtaining the opening coefficient K of the last time₁；

The opening coefficient K of the last time₁When the exhaust temperature is lower than a third preset temperature, the opening degree of the second expansion valve is reduced to a second preset opening degree value;

the opening coefficient K of the last time₁Is a second predetermined opening coefficient value, and whenIf the exhaust temperature is higher than the first preset temperature, increasing the opening degree of the second expansion valve to a first preset opening degree;

the opening coefficient K of the last time₁If the value is a second preset opening coefficient value and the current exhaust temperature is lower than the second preset temperature, reducing the opening of the second expansion valve to a third preset opening;

the opening coefficient K of the last time₁If the value is a third preset opening coefficient value and the current exhaust temperature is higher than the third preset temperature, increasing the opening of the second expansion valve to a second preset opening;

otherwise, keeping the opening degree of the second expansion valve unchanged.

6. The defrosting control method of an air conditioning system according to any one of claims 2 to 5, wherein the initial opening degree of the second expansion valve is obtained by:

wherein the opening C to be corrected is counted by steps; rated refrigerating capacity Mo of heat exchanger of indoor unit_{Inner part}Calculated as 100W; the caliber D of the second expansion valve is measured in mm;

according to rated refrigerating capacity Mo of heat exchanger of outdoor unit_{Outer cover}And obtaining the initial opening degree O' of the second expansion valve according to the opening degree C to be corrected:

wherein, the heat exchanger Mo of the indoor unit_{Outer cover}Calculated as 100 w.

7. The defrosting control method of an air conditioning system according to any one of claims 1 to 5, wherein before the controlling the air conditioning system to perform an indoor unit defrosting operation, the defrosting control method of an air conditioning system further comprises:

judging whether the air conditioning system meets defrosting conditions or not;

if the air conditioning system meets the defrosting condition, executing the step of carrying out the defrosting operation of the indoor unit;

and if the air-conditioning system does not meet the defrosting condition, returning to the step of judging whether the air-conditioning system meets the defrosting condition.

8. The method of claim 7, wherein after the air conditioning system meets the defrosting condition, the method further comprises, before the controlling the air conditioning system to perform an indoor unit defrosting operation:

judging whether the indoor unit is connected with the outdoor unit;

if the indoor unit is connected with the outdoor unit, executing the step of performing the defrosting operation of the indoor unit;

if the indoor unit is not connected with the outdoor unit, executing capillary defrosting operation;

the capillary defrost operation comprising: and controlling the first end of the four-way reversing valve to be connected with the second end of the four-way reversing valve, controlling the third end of the four-way reversing valve to be communicated with the fourth end of the four-way reversing valve, controlling the first expansion valve to be in an open state, and controlling the second expansion valve to be in a closed state.

9. A defrosting control device of an air conditioning system is applied to the air conditioning control system, and the air conditioning system comprises an outdoor unit, at least one indoor unit and at least one group of capillary tubes; the outdoor unit comprises a compressor, a four-way reversing valve and a condenser;

the defrosting control device of the air conditioning system includes:

the processor is used for controlling a fan in each indoor unit of the at least one indoor unit to be closed, controlling the first end of the four-way reversing valve to be communicated with the second end of the four-way reversing valve, controlling the third end of the four-way reversing valve to be communicated with the fourth end of the four-way reversing valve, controlling the first expansion valve to be in a closed state and controlling the second expansion valve to be in an open state;

a communication interface for obtaining a discharge temperature of the compressor;

when the exhaust temperature is higher than a first preset temperature, the processor is further used for enabling the opening degree of the second expansion valve to be a first preset opening degree;

when the exhaust temperature is higher than a second preset temperature and lower than the first preset temperature, the processor is further configured to enable the opening degree of the second expansion valve to be a second preset opening degree;

when the exhaust temperature is lower than the second preset temperature, the processor is further configured to enable the opening degree of the second expansion valve to be a third preset opening degree;

10. An air conditioner comprising the air conditioning system of claim 9, a defrosting control means of the air conditioning system of claim 9, and a temperature sensor provided at an exhaust port of the compressor.