CN112539518B

CN112539518B - Control method of air conditioner

Info

Publication number: CN112539518B
Application number: CN201910894771.2A
Authority: CN
Inventors: 罗荣邦; 许文明
Original assignee: Qingdao Haier Air Conditioner Gen Corp Ltd; Haier Smart Home Co Ltd
Current assignee: Qingdao Haier Air Conditioner Gen Corp Ltd; Haier Smart Home Co Ltd
Priority date: 2019-09-20
Filing date: 2019-09-20
Publication date: 2022-07-19
Anticipated expiration: 2039-09-20
Also published as: CN112539518A

Abstract

The invention relates to the technical field of air conditioning, in particular to a control method of an air conditioner. The invention aims to solve the problem of poor heating effect of the existing air conditioner. To this end, the control method of the present invention includes: acquiring the outdoor environment temperature during heating operation; comparing the outdoor environment temperature with the temperature threshold value; when the outdoor environment temperature is smaller than the temperature threshold value, acquiring the temperature of the heat exchange pipe section; selectively adjusting the opening and closing of a plurality of supercooling valves based on the temperature of the heat exchange pipe section so as to adjust the effective length of the supercooling pipe section; determining the operation opening of the first regulating valve; and adjusting the opening degree of the first regulating valve to the running opening degree. The control method can effectively improve the heating effect of the air conditioner, improve the heating energy efficiency of the air conditioner, inhibit frosting and effectively defrost.

Description

Control method of air conditioner

Technical Field

The invention relates to the technical field of air conditioning, in particular to a control method of an air conditioner.

Background

Compared with a fixed-frequency air conditioner, the variable-frequency air conditioner has the advantages that the frequency of the compressor can be automatically adjusted according to the indoor temperature condition, the indoor environment is guaranteed to be always in a stable temperature range, and therefore the variable-frequency air conditioner is more and more popular.

The traditional inverter air conditioner only examines refrigeration energy efficiency and power, takes the refrigeration energy efficiency as an energy efficiency grade evaluation standard, and has no requirement on heating power and capacity, so that research and development personnel generally take the optimal refrigeration energy efficiency as a design principle when developing the inverter air conditioner. However, with the development and implementation of the new national energy efficiency standard, the refrigeration power, the heating power and the energy efficiency of the inverter air conditioner are all in the examination range, and the heating energy efficiency has a great influence on the overall energy efficiency of the air conditioner, so that the heating power of the inverter air conditioner is reduced, and the heating energy efficiency of the inverter air conditioner is improved to become one of the most critical tasks in the industry at present.

In addition, in the process of low-temperature heating, especially when heating is performed in a low-temperature and high-humidity environment, the frosting speed of the outdoor unit is high, and the heating effect is seriously reduced along with the thickening of the frost layer, so that how to effectively defrost while improving the heating energy efficiency is also one of the difficulties in the field.

Accordingly, there is a need in the art for a new control method of an air conditioner to solve the above-mentioned problems.

Disclosure of Invention

In order to solve the above problems in the prior art, i.e. to solve the problem of poor heating effect of the prior air conditioner, the present invention provides a control method of an air conditioner, the air conditioner comprises a compressor, an outdoor unit condenser, a second regulating valve and an indoor unit evaporator, the outdoor condenser comprises a heat exchange pipe section, an supercooling pipe section, a first regulating valve, a supercooling connecting pipe and a plurality of supercooling valves, the first end of the supercooling pipe section is connected with the indoor unit evaporator through the second regulating valve, the first end and the second end of the supercooling pipe section are divided into n supercooling intervals by the plurality of supercooling valves, wherein a plurality of the supercooling intervals are respectively connected with the first end of the first regulating valve through a supercooling connecting pipe, the second end of the first regulating valve is connected with the heat exchange tube section, and the control method comprises the following steps:

acquiring the outdoor environment temperature during heating operation;

comparing the outdoor environment temperature with the temperature threshold value;

when the outdoor environment temperature is less than the temperature threshold, acquiring the temperature of the heat exchange tube section;

selectively adjusting the opening and closing of the plurality of subcooling valves based on the temperature of the heat exchange tube section to adjust the effective length of the subcooling tube section;

determining the operation opening degree of the first regulating valve;

and adjusting the opening degree of the first regulating valve to the operation opening degree.

In a preferred embodiment of the above method for controlling an air conditioner, the step of "selectively adjusting the opening and closing of the plurality of supercooling valves based on the temperature of the heat exchange pipe section" further includes:

acquiring and recording the temperature of the heat exchange pipe section in a set time period every other set time period;

calculating a rate of change of temperature of the heat exchange tube segment over the set time period based on the temperature and the set time period;

comparing the temperature change rate with a set threshold value;

and when the temperature change rate is greater than the set threshold value and lasts for a preset time, adjusting the opening and closing of the plurality of supercooling valves to increase the effective length of the supercooling pipe section until the effective length of the supercooling pipe section is increased to the longest length.

In a preferred embodiment of the control method of the air conditioner, before the step of "selectively adjusting the opening and closing of the plurality of supercooling valves", the control method further includes:

and adjusting the opening and closing of the plurality of supercooling valves so as to minimize the effective length of the supercooling pipe section.

In a preferred embodiment of the control method of the air conditioner, a second end of the supercooling pipe segment is connected to the heat exchange pipe segment, the outdoor condenser further includes a confluence connection pipe and a plurality of confluence valves, each of the plurality of supercooling sections is connected to a second end of the first regulating valve through one of the confluence connection pipes, and each of the confluence connection pipes is provided with one of the confluence valves, and the control method further includes:

and adjusting the opening and closing of the plurality of confluence valves simultaneously, before or after adjusting the opening and closing of the plurality of supercooling valves so as to communicate the part outside the effective length with the heat exchange pipe section.

In a preferred embodiment of the control method of the air conditioner, the outdoor unit condenser further includes a plurality of on-off valves, and each of the plurality of subcooling connecting pipes is provided with one of the on-off valves, and the control method further includes:

adjusting opening and closing of the plurality of on-off valves to cut off communication between a portion other than the effective length and the effective length, simultaneously with, before, or after adjusting opening and closing of the plurality of supercooling valves.

In a preferred embodiment of the control method of the air conditioner, the control method further includes:

and when the outdoor environment temperature is greater than or equal to the temperature threshold, adjusting the opening and closing of the plurality of supercooling valves so as to enable the effective length of the supercooling pipe section to be the shortest.

In a preferable embodiment of the control method of an air conditioner, the step of "determining the operation opening degree of the first adjusting valve" further includes:

acquiring the outdoor environment temperature and the working frequency of the compressor;

calculating a theoretical temperature of the supercooling pipe section based on the outdoor environment temperature;

and calculating the operation opening of the first regulating valve based on the outdoor environment temperature, the working frequency and the theoretical temperature.

In a preferred embodiment of the control method of an air conditioner, after the step of "adjusting the opening degree of the first regulating valve to the operation opening degree", the control method further includes:

acquiring the actual temperature of the supercooling pipe section;

and carrying out PID (proportion integration differentiation) adjustment on the opening degree of the first adjusting valve based on the difference value between the theoretical temperature and the actual temperature.

acquiring the outdoor environment temperature and the running frequency of the compressor;

calculating a heating target exhaust temperature of the air conditioner based on the outdoor environment temperature and the operating frequency;

and controlling the opening degree of the second regulating valve based on the heating target exhaust temperature.

In a preferred embodiment of the above method for controlling an air conditioner, the step of "obtaining an outdoor ambient temperature and an operating frequency of the compressor" further comprises:

and when the actual temperature of the supercooling pipe section reaches the theoretical temperature, acquiring the outdoor environment temperature and the running frequency of the compressor.

As can be understood by those skilled in the art, in a preferred embodiment of the present invention, an air conditioner includes a compressor, an outdoor unit condenser, a second regulating valve, and an indoor unit evaporator, the outdoor unit condenser includes a heat exchange pipe section, an supercooling pipe section, a first regulating valve, a supercooling connecting pipe, and a plurality of supercooling valves, a first end of the supercooling pipe section is connected to the indoor unit evaporator through the second regulating valve, a first end and a second end of the supercooling pipe section are partitioned into n supercooling sections by the plurality of supercooling valves, wherein the plurality of supercooling sections are respectively connected to a first end of the first regulating valve through the supercooling connecting pipe, and a second end of the first regulating valve is connected to the heat exchange pipe section, and the control method includes: acquiring the outdoor environment temperature during heating operation; comparing the outdoor environment temperature with the temperature threshold value; when the outdoor environment temperature is smaller than the temperature threshold value, acquiring the temperature of the heat exchange pipe section; selectively adjusting the opening and closing of a plurality of supercooling valves based on the temperature of the heat exchange pipe section so as to adjust the effective length of the supercooling pipe section; determining the operation opening of the first regulating valve; and adjusting the opening degree of the first regulating valve to the operation opening degree.

When the outdoor environment temperature is lower than the temperature threshold value, the opening and closing of the supercooling valve are selectively adjusted according to the temperature of the heat exchange pipe section, so that the effective length of the supercooling pipe section is adjusted. Specifically, when the outdoor environment temperature is less than the temperature threshold, especially in the low-temperature and high-humidity outdoor environment, the outdoor unit condenser is easily frosted during the heating operation of the air conditioner, and the frosted outdoor unit condenser seriously affects the heating efficiency of the air conditioner and reduces the heating energy efficiency. This application sets up throttling element between heat exchange tube section and subcooling pipe section to it is between being divided into n subcooling with the subcooling pipe section to use a plurality of subcooling valve, so, through throttling element's secondary throttle, make outdoor subcooling pipe section can carry out the condensation heat exchange as the replenishment of indoor evaporimeter at the heating in-process, thereby hot-air flow after the condensation heat exchange can carry out the heat exchange once more with the heat exchange tube section, can restrain the frosting of heat exchange tube section, can in time defrost when the heat exchange tube section frosts again. On the basis, the number of supercooling intervals playing a supercooling role in the supercooling pipe section can be controlled by controlling the opening and closing of different supercooling valves, so that the effective length of the supercooling pipe section can be adjusted, and the frosting degree and the defrosting effect can be further controlled. The operation opening of the first regulating valve is determined in the heating process, and the opening of the first regulating valve is adjusted to the operation opening, so that when the air conditioner heats, the opening of the first regulating valve is controlled to enable the supercooling pipe section to reach a better temperature, the supercooling degree of the air conditioning system is accurately controlled, the heating effect of the air conditioner is optimal, and the heating energy efficiency is improved.

Further, the effective length of the supercooling pipe section is adjusted based on the change rate of the temperature every set time period, the control method can correspondingly adjust the defrosting capacity based on the frosting condition of the current heat exchange pipe section, improves the defrosting effect, avoids the condition that the defrosting capacity is not matched with the frosting degree, and ensures the heating efficiency.

Furthermore, the opening and closing of the confluence valve are adjusted while, before or after the opening and closing of the supercooling valve are adjusted, so that the part outside the effective length is communicated with the heat exchange tube section.

Further, through when, before or after adjusting the subcooling valve and open and close, the switching of adjustment on-off valve to cut off the intercommunication between the part outside the effective length and the effective length, the control method of this application can also improve the utilization ratio of the refrigerant in the subcooling pipe section, guarantees heat exchange efficiency.

Furthermore, the theoretical temperature of the supercooling pipe section is calculated based on the outdoor environment temperature, and then the opening of the first regulating valve is calculated and controlled based on the outdoor environment temperature, the working frequency of the compressor and the theoretical temperature of the supercooling pipe section, so that when the air conditioner heats, the first regulating valve can be controlled to be opened to the opening capable of enabling the supercooling pipe section to reach the better temperature based on the outdoor environment condition, the supercooling degree of the air conditioning system is accurately controlled, the heat exchange effect of the air conditioner is enabled to be optimal, the heating energy efficiency is improved, the frosting is inhibited, and the defrosting is effectively carried out.

Furthermore, after the opening degree of the first regulating valve is adjusted to the operation opening degree, PID control is carried out on the opening degree of the first regulating valve based on the difference value between the theoretical temperature and the actual temperature of the supercooling pipe section, the control method can also dynamically, quickly and accurately adjust the opening degree of the first regulating valve, and the problem that the first regulating valve is over-adjusted or over-adjusted is prevented.

Further, when the actual temperature of the supercooling pipe section reaches the theoretical temperature, the heating target exhaust temperature of the air conditioner is calculated based on the outdoor environment temperature and the operation frequency of the compressor, and the opening of the second regulating valve is controlled based on the heating target exhaust temperature.

Drawings

A control method of an air conditioner of the present invention is described below with reference to the accompanying drawings. In the drawings:

fig. 1 is a system diagram of a variable frequency air conditioner according to a first embodiment of the present invention;

FIG. 2 is a system diagram of a variable frequency air conditioner according to a second embodiment of the present invention;

FIG. 3 is a partial schematic view of a variable frequency air conditioner according to a third embodiment of the present invention;

FIG. 4 is a partial schematic view of a variable frequency air conditioner according to a fourth embodiment of the present invention;

fig. 5 is a flowchart illustrating a control method of an air conditioner according to the present invention;

fig. 6 is a logic diagram of a control method of an air conditioner according to the present invention.

List of reference numerals

1. A variable frequency compressor; 2. a four-way valve; 3. an indoor unit evaporator; 4. an indoor fan; 5. an outdoor condenser; 51. a heat exchange tube section; 52. an overcooling pipe section; 53. a first regulating valve; 54. a super-cooled connecting pipe; 55a, 55b, 55c, supercooling valves; 56. a confluence connecting pipe; 57a, 57b, 57c, confluence valves; 58a, 58b, 58c, on-off valves; 6. an outdoor fan; 7. a second regulator valve.

Detailed Description

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only for explaining the technical principle of the present invention, and are not intended to limit the scope of the present invention. For example, although the following embodiments describe each step as a sequential order, those skilled in the art can understand that, in order to achieve the effect of the present embodiments, different steps need not be executed in such an order, and they may be executed simultaneously (in parallel) or in an inverse order, and these simple variations are within the scope of the present invention.

It should be noted that in the description of the present invention, the terms of direction or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, which are merely for convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Furthermore, it should be noted that, in the description of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; 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 meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Example 1

Referring first to fig. 1, an inverter air conditioner of the present invention will be described. Fig. 1 is a system schematic diagram of a variable frequency air conditioner according to a first embodiment of the present invention.

As shown in fig. 1, in order to solve the problem of low heating efficiency of the conventional inverter air conditioner, the present application provides an inverter air conditioner, which includes an indoor unit, an outdoor unit, and a pipeline connecting the indoor unit and the outdoor unit. The outdoor unit comprises a variable frequency compressor 1, a four-way valve 2, an outdoor unit condenser 5, an outdoor fan 6 and a second regulating valve 7, and the indoor unit comprises an indoor unit evaporator 3 and an indoor fan 4. The outdoor condenser 5 comprises a heat exchange pipe section 51, a supercooling pipe section 52, a first regulating valve 53, a supercooling connecting pipe 54 and a plurality of supercooling valves (55a and 55b), wherein the heat exchange pipe section 51 and the supercooling pipe section 52 are formed by connecting U-shaped pipes end to end, the first end (the lower end in the figure 1) of the supercooling pipe section 52 is connected with the indoor unit evaporator 3 through a second regulating valve 7, the supercooling valves (55a and 55b) are arranged on the supercooling pipe section 52 and divide the space between the first end and the second end (the upper end in the figure 1) of the supercooling pipe section 52 into n supercooling sections, the supercooling sections are respectively connected with the first end (the right end in the figure 1) of the first regulating valve 53 through the supercooling connecting pipe 54, and the second end (the left end in the figure 1) of the first regulating valve 53 is connected with the heat exchange pipe section 51. The supercooling valves (55a, 55b) are set to adjust the effective length of the supercooling pipe section 52 by controlling the opening and closing of each supercooling valve (55a, 55b), and the first regulating valve 53 is set to be fully opened when the heat exchange medium (such as refrigerant) flows from the outdoor condenser 5 to the indoor evaporator 3 and to be opened at a set opening when the heat exchange medium flows from the indoor evaporator 3 to the outdoor condenser 5.

It should be noted that, in the present application, the effective length refers to the length of the partial pipe section of the supercooling pipe section 52 for performing the supercooling function, which can be controlled by controlling the opening and closing of the supercooling valve, and the effective length is the longest, that is, the entire length of the supercooling pipe section 52. The set opening degree refers to any opening degree between the fully closed state and the fully open state, and the size of the specific opening degree can be controlled based on parameters, such as outdoor ambient temperature, temperature of the supercooling pipe section 52 and the like.

Referring to fig. 1, taking the heat exchange medium as an example, when the inverter air conditioner operates in a cooling mode, the first regulating valve 53 is fully opened, the second regulating valve 7 is opened to a set opening degree according to a conventional control mode, the refrigerant is discharged from an exhaust port of the inverter compressor 1 and then enters the outdoor condenser 5, sequentially flows through the heat exchange pipe section 51, the first regulating valve 53, the supercooling connecting pipe 54 and the supercooling pipe section 52 to perform condensation heat exchange with outdoor air, the refrigerant after heat exchange enters the indoor evaporator 3 to perform evaporation heat exchange with indoor air after being throttled by the second regulating valve 7, and the refrigerant after heat exchange returns to the inverter compressor 1 from an air suction port of the inverter compressor 1 to complete a cooling cycle. When the inverter air conditioner operates in a heating mode, the first regulating valve 53 and the second regulating valve 7 are respectively opened to set opening degrees, the supercooling valves (55a and 55b) are opened and closed according to a set control mode to regulate the effective length of the supercooling pipe section 52, the refrigerant firstly enters the indoor unit evaporator 3 to perform condensation heat exchange with indoor air after being discharged through the exhaust port of the inverter compressor 1, the refrigerant after heat exchange enters the supercooling pipe section 52 after being subjected to first throttling and cooling by the second regulating valve 7, the temperature of the refrigerant entering the supercooling pipe section 52 is still high, the refrigerant in the effective length part of the supercooling pipe section 52 performs further condensation heat exchange with outdoor air, then flows into the first regulating valve 53 through the supercooling connecting pipe 54, enters the heat exchange pipe section 51 to perform evaporation heat exchange with the outdoor air under the secondary throttling of the first regulating valve 53, and the heat exchanged refrigerant returns to the inverter compressor 1 from the air suction port of the inverter compressor 1, completing one heating cycle.

As can be seen from the above description, by providing the first regulating valve 53 between the heat exchange tube section 51 and the supercooling tube section 52 of the outdoor unit condenser 5, when the inverter air conditioner is refrigerating, the first regulating valve 53 can be prevented from affecting the refrigeration energy efficiency by fully opening the first regulating valve 53, and by adjusting the opening degree of the second regulating valve 7, the normal frequency regulation of the air conditioner can be realized; during heating, the opening change of the first regulating valve 53 is controlled, so that the supercooling degree can be accurately controlled, the supercooling pipe section 52 of the outdoor condenser 5 serves as extension and supplement of the indoor evaporator 3, the heat exchange area of the indoor evaporator 3 is increased in a phase-changing manner, the supercooling section on the high-pressure side is lengthened, the temperature of a heat exchange medium can be further reduced, the saturation pressure on the high-pressure side is reduced, the power of a compressor is reduced, and the heating energy consumption is greatly reduced. Through repeated experiments, observation, analysis and comparison of the inventor, under the condition of adopting the arrangement mode, the heating energy efficiency of the air conditioner applying the heat exchanger can be accurately controlled and basically reaches the refrigeration energy efficiency level.

Further, by dividing the supercooling pipe section 52 into n supercooling sections using the plurality of supercooling valves (55a, 55b), and connecting the plurality of supercooling sections to the first end of the first adjusting valve 53 through the supercooling connecting pipe 54, it is possible to adjust the effective length of the supercooling pipe section 52 by adjusting the opening and closing of the plurality of supercooling valves (55a, 55b) at the time of heating, thereby suppressing frost formation or performing a defrosting operation for the outdoor unit condenser 5 by a change in the effective length of the supercooling pipe section 52, and improving heating efficiency.

The first embodiment of the inverter air conditioner of the present application will be described in detail with further reference to fig. 1, in conjunction with two supercooling valves (55a, 55b) provided on the supercooling pipe section 52.

In a more preferred embodiment, as shown in fig. 1, two subcooling valves (55a, 55b) divide the subcooling tube section 52 into three subcooling sections, each of which is connected to a first end of a first regulating valve 53 by a subcooling connecting tube 54. Wherein, each supercooling connecting pipe 54 is further provided with an on-off valve (58a, 58b, 58 c). By controlling the opening and closing of the supercooling valves (55a, 55b) and the on-off valves (58a, 58b, 58c), the effective length of the supercooling pipe section 52 can be controlled. For example, when the subcooling valve 55a is closed and the on-off valves 58a are open and 58b and 58c are closed, the effective length of the subcooling tube section 52 is the length of the first subcooling section adjacent to the first end (lower end in fig. 1) of the subcooling tube section 52; when the subcooling valve 55a is opened, the subcooling valve 55b is closed, the on-off valve 58b is opened, the on-off

valves

58a and 58c are closed, the effective length of the subcooling pipe section 52 is the sum of the lengths of the first subcooling section and the second subcooling section from the first end of the subcooling pipe section 52, and so on. The supercooling valves (55a, 55b) and the on-off valves (58a, 58b, 58c) can be electrically controlled valves such as electromagnetic valves and electronic expansion valves.

Through the arrangement of the supercooling valves (55a and 55b) and the on-off valves (58a, 58b and 58c), the effective length of the supercooling pipe section 52 can be adjusted by adjusting the opening and closing of the supercooling valves (55a and 55b) and the on-off valves (58a, 58b and 58c) during heating, so that the frosting is inhibited or the defrosting operation is performed on the outdoor condenser 5 through the change of the effective length of the supercooling pipe section 52, and the heating efficiency is improved.

With continued reference to fig. 1, in a preferred embodiment, the outdoor condenser 5 is a double-row heat exchanger, and the subcooling pipe section 52 is disposed below the heat exchange pipe section 51 and on the windward side (i.e., the right side in fig. 1) of the outdoor condenser 5.

By arranging the supercooling pipe section 52 on the windward side and below the heat exchange pipe section 51, the heat exchange capacity of the heat exchange pipe section 51 on the leeward side can be increased, the compressor power can be further reduced, and the frost formation can be suppressed or the defrosting effect can be improved. This is because, the temperature of the heat exchange medium in the supercooling section tube after primary throttling is still higher than the ambient temperature, and before secondary throttling, heat exchange is performed with the air flow through the supercooling section 52, so that the heat released by the supercooling section 52 is blown to the heat exchange tube section 51 on the leeward side along with the air flow to perform heat exchange, and the heat exchange medium in the heat exchange tube section 51 on the leeward side is throttled for the second time to reach a low-temperature and low-pressure state, and the heat exchange tube of the primary section is full and is easier to frost.

Still referring to fig. 1, in a preferred embodiment, the outdoor condenser 5 further includes a defrosting temperature detecting element (not shown) disposed on the heat exchange tube section 51, preferably on the initial section of the heat exchange tube section 51, and the defrosting temperature detecting element can be connected to a controller of the inverter air conditioner, so that the controller can control the opening and closing of the supercooling valves (55a, 55b), i.e. adjust the effective length of the supercooling tube section 52, based on the temperature of the heat exchange tube section 51 collected by the defrosting temperature detecting element during heating operation. The defrosting temperature detecting element may be a temperature sensor, a thermal bulb, or the like, which is attached to the outer surface of the U-shaped tube at the initial section of the heat exchanging tube section 51 and connected to the controller through a lead. Wherein, the controller can be the controller of the air conditioner.

By arranging the defrosting temperature detection element at the initial section of the heat exchange pipe section 51, the controller can timely and reasonably adjust the opening and closing of the supercooling valves (55a and 55b) and the on-off valves (58a, 58b and 58c) based on the temperature of the heat exchange pipe section 51, so that the effective length of the supercooling pipe section 52 can be adjusted, the heat exchange effect of the supercooling pipe section is ensured, the frosting of a heat exchange pipeline is inhibited, and the heating effect is improved.

With continued reference to fig. 1, in a preferred embodiment, the outdoor condenser 5 further includes a supercooling temperature detecting element (not shown) disposed on the supercooling pipe section 52 and capable of being connected to a controller of the inverter air conditioner, so that the controller can control the opening degree of the first adjusting valve 53 based on the temperature of the supercooling pipe section 52 collected by the supercooling temperature detecting element during heating operation. The supercooling temperature detecting element may be a temperature sensor, a temperature sensing bulb, or the like, which is attached to the outer surface of the U-shaped pipe of the supercooling pipe section 52 and connected to the controller through a lead. The controller may be a controller of an air conditioner, a PID regulator, or the like.

By arranging the supercooling temperature detection element on the supercooling pipe section 52, the opening degree of the first regulating valve 53 can be regulated based on the temperature of the supercooling pipe section 52, so that the first regulating valve 53 can be accurately regulated during heating, the power of the compressor is reduced, and the heating energy efficiency is improved.

With continued reference to fig. 1, in a more preferred embodiment, the heat exchange tube section 51 is divided into a plurality of flow paths, the cross-sections of which are N-type and/or N-type. Specifically, the heat exchange tube section 51 in this embodiment has two flow paths, one of which is N-shaped and the other is N-shaped in cross section, and the flow directions of the two flow paths are from the windward side to the leeward side. In this way, by dividing the heat exchange pipe section 51 into a plurality of flow paths, the refrigerant exchanges heat in multiple paths simultaneously in the heat exchange process, and the heat exchange efficiency and the heat exchange effect are ensured. The flow direction of the two flow paths is set to flow from the windward side to the leeward side, so that the temperature of air flow subjected to heat exchange with the refrigerant on the windward side is increased in the flowing process of the refrigerant, and then the air flow is subjected to heat exchange with the refrigerant on the leeward side, the heat exchange effect of the heat exchange tube section 51 is improved, and frosting can be inhibited.

Of course, it will be understood by those skilled in the art that the above arrangement is not a constant one and that modifications may be made by those skilled in the art without departing from the principles of the present application, provided that the modifications are sufficient to divide the heat exchange tube section 51 into a plurality of flow paths, each flow path having an N-type and/or N-type cross-section. For example, the flow path may be divided into three or more, and each flow path may be N-type or N-type in cross section.

In a more preferred embodiment, the first regulating valve 53 and the second regulating valve 7 are both electronic expansion valves in the present embodiment, wherein the first regulating valve 53 is set to be fully opened when the inverter air conditioner operates in the cooling mode, and is opened at a set opening degree when the inverter air conditioner operates in the heating mode, and the second regulating valve 7 is set to be opened at a required throttle opening degree in both cooling and heating. The arrangement of the first regulating valve 53 and the second regulating valve 7 enables the inverter air conditioner to accurately regulate the supercooling degree of the system in the heating process by regulating the opening degree of the two regulating valves, so that the heating power is reduced, and the heating energy efficiency is improved.

Although the first regulating valve 53 and the second regulating valve 7 are both electronic expansion valves in the present embodiment, this is not limitative, and those skilled in the art can modify them based on the specific application, for example, the first regulating valve 53 and/or the second regulating valve 7 can also be electronic control valves such as solenoid valves.

Referring to fig. 2, a second embodiment of the inverter air conditioner of the present application will be described with reference to the supercooling pipe section 52 having three supercooling valves (55a, 55b, 55 c).

In a more preferred embodiment, as shown in fig. 2, three subcooling valves (55a, 55b, 55c) divide the subcooling tube section 52 into four subcooling sections, and each of the first to third subcooling sections from the bottom to the top of the four subcooling sections is connected to the first end of the first regulating valve 53 by a subcooling connecting pipe 54. Wherein, each supercooling connecting pipe 54 is also provided with an on-off valve (58a, 58b, 58c), and the effective length of the supercooling pipe section 52 can be controlled by controlling the opening and closing of the supercooling valve (55a, 55b, 55c) and the on-off valve (58a, 58b, 58 c). Specifically, the second end of the supercooling pipe segment 52 is further connected to the heat exchange pipe segment 51, the outdoor condenser 5 further includes three confluence connection pipes 56 and three confluence valves (57a, 57b, and 57c), each of the four supercooling sections from the second supercooling section from the bottom to the fourth supercooling section is connected to the second end of the first regulating valve 53 through one confluence connection pipe 56, and each confluence connection pipe 56 is further provided with one confluence valve (57a, 57b, and 57 c). In this way, during heating, the effective length of the supercooling pipe section 52 can be adjusted by jointly controlling the supercooling valves (55a, 55b, 55c), the confluence valves (57a, 57b, 57c) and the on-off valves (58a, 58b, 58c), and the remaining pipes other than the effective length of the supercooling pipe section 52 are connected to the heat exchange pipe section 51 through the confluence connection pipe 56 and the confluence valves to participate in the evaporation heat exchange.

For example, when the supercooling valve 55a is closed, the 55b and 55c are opened, the on-off valve 58a is opened, the 58b and 58c are closed, and the confluence valve 57a is opened, the 57b and 57c are closed, the effective length of the supercooling section 52 is the length of the first supercooling section near the first end (the lower end in fig. 1) of the supercooling section 52, the second supercooling section and the fourth supercooling section are connected to the heat exchange pipe section 51, and part of the refrigerant flowing out of the second end of the first regulating valve 53 flows through the confluence valve 57a to the fourth supercooling section in sequence and flows into the heat exchange pipe section 51; when the supercooling valve 55b is closed, the on-off

valves

58b and 58a are opened, the on-off

valves

58b and 58c are closed, the confluence valve 55b is opened, and the 55a and 55c are closed, the effective length of the supercooling pipe section 52 is the sum of the lengths of the first supercooling section and the second supercooling section from the first end of the supercooling pipe section 52, the third supercooling section and the fourth supercooling section are connected with the heat exchange pipe section 51, and so on. The supercooling valve, the confluence valve and the on-off valve can be electric control valves such as an electromagnetic valve and an electronic expansion valve.

Through the arrangement of the supercooling valves (55a, 55b and 55c), the confluence valves (57a, 57b and 57c) and the on-off valves (58a, 58b and 58c), when heating is performed, the effective length of the supercooling pipe section 52 and the effective length of part of the heat exchange pipe section 51 can be skillfully adjusted through combined adjustment of the opening and closing of the supercooling valves, the confluence valves and the on-off valves, so that the frost formation is inhibited or the defrosting operation is performed on the outdoor unit condenser 5 through the change of the effective length of the supercooling pipe section 52, the heating efficiency is improved, the residual pipes of the supercooling pipe section 52 are reasonably utilized to supplement the heat exchange pipe section 51, and the evaporation heat exchange effect of the heat exchange pipe section 51 is improved.

Of course, it will be understood by those skilled in the art that the number and arrangement of the subcooling valves (55a, 55b, 55c), the combining valves (57a, 57b, 57c) and the on-off valves (58a, 58b, 58c) in the first and second embodiments are not limiting and can be modified by those skilled in the art without departing from the principles of the present application so that the present application can be adapted to more specific application scenarios.

For example, although the first embodiment and the second embodiment are described in conjunction with the provision of two supercooling valves (55a, 55b) and three supercooling valves (55a, 55b, 55c), it is obvious that the number of supercooling valves is not limited thereto, and those skilled in the art can reasonably adjust the number, for example, one, four or more supercooling valves may be provided. Likewise, the number of the confluence valves and the make-and-break valves can be adjusted, so long as the adjustment is ensured to be in accordance with the principle of the present application, and the details are not repeated herein.

As another example, fig. 3 and 4 respectively show partial schematic views of a third embodiment and a fourth embodiment of the inverter air conditioner of the present application. As shown in fig. 3, on the basis of the first or second embodiment, a person skilled in the art may omit the setting of the on-off valve, and then effectively guide the refrigerant by reasonably setting the radian of the supercooling connecting pipe 54, so as to prevent the refrigerant from flowing backwards in the cooling or heating process. As shown in fig. 4, a person skilled in the art may replace the on-off valve with a one-way valve on the basis of the first or second embodiment, and only a part of the supercooling pipeline is provided to prevent the refrigerant from flowing backwards in the heating process.

Of course, the above alternative embodiments, and the alternative embodiment and the preferred embodiment may also be used in a cross-matching manner, so that a new embodiment is combined to be suitable for a more specific application scenario. For example, the third and fourth embodiments are combined, and a check valve is added to the partial supercooling connection pipe 54 in addition to setting the arc degree of the supercooling connection pipe 54 appropriately.

The operation of the inverter air conditioner of the present invention will be briefly described with reference to fig. 2.

As shown in fig. 2, when the inverter air conditioner operates in the cooling mode, the first regulating valve 53 is fully opened, the second regulating valve 7 is opened to a set opening, all supercooling valves (55a, 55b, 55c) are fully opened, all confluence valves (57a, 57b, 57c) and on-off valves (58a, 58b, 58c) are fully closed, the refrigerant is discharged through the exhaust port of the inverter compressor 1, enters the outdoor unit condenser 5, flows through the N-type flow path and the N-type flow path of the heat exchange tube section 51 simultaneously to perform condensation heat exchange with outdoor air, then is converged into one flow path after the first regulating valve 53, then enters the indoor unit evaporator 3 to perform evaporation heat exchange with indoor air after throttling of the second regulating valve 7, and the heat exchanged refrigerant returns to the inverter compressor 1 from the suction port of the inverter compressor 1 to complete one cooling cycle.

When the inverter air conditioner operates in a heating mode, the first regulating valve 53 and the second regulating valve 7 are respectively opened to set opening degrees, the supercooling valves 55a are closed, 55b and 55c are opened, the on-off valves 58a and 58b and 58c are closed, the confluence valves 57a and 57b and 57c are closed, a refrigerant is discharged from an exhaust port of the inverter compressor 1 and firstly enters the indoor unit evaporator 3 to perform condensation heat exchange with indoor air, the refrigerant after heat exchange is subjected to primary throttling and cooling through the second regulating valve 7 and then enters a first supercooling section of a supercooling pipe section 52 of the outdoor unit condenser 5, the temperature of the refrigerant entering the first supercooling section is still high, at the moment, after the refrigerant is further subjected to condensation heat exchange with outdoor air, the refrigerant enters second to fourth supercooling sections of the supercooling pipe section 52 after the part of the secondary throttling of the first regulating valve 53 passes through the I-shaped heat exchange pipe section 51 and the confluence connecting pipe 56 behind the first regulating valve 53, then enters the N-shaped flow path of the heat exchange tube section 51 to perform evaporation heat exchange with outdoor air, and the other part of the refrigerant passes through the I-shaped heat exchange tube section 51 after passing through the first regulating valve 53 and enters the N-shaped flow path of the heat exchange tube section 51 to perform evaporation heat exchange with outdoor air. The refrigerants after heat exchange are converged into a flow path and then return to the inverter compressor 1 from the air suction port of the inverter compressor 1, and a heating cycle is completed. In the heat exchange process, the temperature of the air flow after heat exchange with the supercooling pipe section 52 and the windward heat exchange pipe section 51 is increased, and then heat exchange is performed with the leeward I-shaped heat exchange pipe section 51, so that frosting is inhibited. If it is judged that the I-type heat exchange pipe section 51 is frosted by temperature sensing of the frosting temperature sensing element during heating, the opening and closing of the supercooling valves (55a, 55b, 55c), the on-off valves (57a, 57b, 57c) and the confluence valves (58a, 58b, 58c) are properly controlled to change the effective length of the supercooling pipe section 52 and the effective length of a part of the heat exchange pipe section 51, and defrosting is rapidly performed by increasing the effective length of the supercooling pipe section 52.

Of course, the control process described above may be modified by those skilled in the art. For example, during cooling operation, the

supercooling valves

55a, 55b, and 55c are closed, the on-off

valves

58a, 58b, and 58c are closed, and the

confluence valve

57a, 57b, and 57c are opened, so that the refrigerants are merged into one path before the first regulating valve 53 and are further supercooled by passing through a part of the cooling pipe section.

It will be appreciated by those of skill in the art that although some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the claims of the present invention, any of the claimed embodiments may be used in any combination.

Example 2

A heating control method of the air conditioner according to the present invention will be described with reference to fig. 2 and 5. Fig. 5 is a flowchart illustrating a control method of an air conditioner according to the present invention.

As shown in fig. 5, the present application also provides a control method of an inverter air conditioner corresponding to the inverter air conditioner, and the specific structure of the inverter air conditioner is described in embodiment 1 and is not described herein again. The control method comprises the following steps:

s100, acquiring outdoor environment temperature during heating operation; for example, during heating operation of the air conditioner, the outdoor ambient temperature is acquired by a temperature sensor provided in the outdoor unit.

S200, comparing the outdoor environment temperature with the temperature threshold value; for example, the temperature threshold is a temperature that can reflect whether the outdoor unit is easily frosted, and for example, the temperature threshold is 5 ℃, and after the outdoor ambient temperature is obtained, the outdoor ambient temperature is compared with 5 ℃. Of course, the temperature threshold is only an example, and those skilled in the art may adjust the temperature threshold based on a specific application scenario, for example, adjust the temperature threshold based on a test or an empirical value, as long as the temperature value can be used as a critical value reflecting whether the outdoor unit is easily frosted.

S300, when the outdoor environment temperature is smaller than a temperature threshold value, acquiring the temperature of the heat exchange pipe section 51; for example, still taking the temperature threshold as 5 ℃ for example, when the outdoor ambient temperature is less than 5 ℃, it is proved that the outdoor unit is easy to frost, and at this time, the temperature of the heat exchange tube section 51 needs to be obtained for further analysis, and whether the heat exchange tube section 51 has frosted or not is judged.

S400, selectively adjusting the opening and closing of a plurality of supercooling valves (55a, 55b and 55c) based on the temperature of the heat exchange pipe section 51 so as to adjust the effective length of the supercooling pipe section 52; for example, when the temperature of the heat exchange tube section 51 is continuously lower than a certain temperature value, it is proved that the heat exchange tube section 51 is frosted, and at this time, the opening and closing of a plurality of supercooling valves (55a, 55b, 55c) need to be adjusted to adjust the effective length of the supercooling tube section 52, that is, the number of supercooling sections playing a supercooling role in the supercooling tube section 52, so as to improve the defrosting capacity of the outdoor unit condenser 5 and defrost the outdoor unit condenser 5 in time. The method for adjusting the effective length of the subcooling pipe section 52 is described in example 1 and will not be described herein.

S500, determining the operation opening of the first regulating valve 53; for example, the operation opening degree may be determined based on the correspondence relationship between the current temperature of the supercooling pipe section 52 and the opening degree of the first regulating valve 53, or may be determined based on a fitting equation between a parameter such as the outdoor ambient temperature and the first regulating valve 53.

S600, adjusting the opening degree of the first adjusting valve 53 to an operation opening degree; after the operation opening degree of the first adjusting valve 53 is determined, the first adjusting valve 53 is controlled to adjust to the operation opening degree, so as to ensure that the air conditioner operates in a better state.

When the outdoor environment temperature is smaller than the temperature threshold value, the opening and closing of the supercooling valves (55a, 55b and 55c) are selectively adjusted according to the temperature of the heat exchange pipe section 51, so that the effective length of the supercooling pipe section 52 is adjusted. Specifically, when the outdoor environment temperature is less than the temperature threshold, especially in the low-temperature and high-humidity outdoor environment, the outdoor unit condenser 5 is easily frosted during the heating operation of the air conditioner, and the frosted outdoor unit condenser seriously affects the heating efficiency of the air conditioner, thereby reducing the heating energy efficiency. This application sets up first governing valve 53 between heat exchange tube section 51 and subcooling tube section 52 to use a plurality of subcooling valve (55a, 55b, 55c) to divide subcooling tube section 52 into a plurality of subcooling intervals, so, secondary throttling through first governing valve 53, make outdoor subcooling tube section 52 can carry out the condensation heat exchange as the replenishment of indoor evaporimeter in the heating process, thereby the hot-air current after the condensation heat exchange can carry out the heat exchange again with heat exchange tube section 51, can restrain the frosting of heat exchange tube section 51, can in time defrost when heat exchange tube section 51 frosts again. On the basis, the number of supercooling sections playing a supercooling role in the supercooling pipe section 52 can be controlled by controlling the opening and closing of different supercooling valves (55a, 55b and 55c), so that the effective length of the supercooling pipe section 52 is adjusted, and the frosting degree and the defrosting effect are controlled. By determining the operation opening degree of the first adjusting valve 53 and adjusting the opening degree to the operation opening degree in the heating process, when the air conditioner is heating, the supercooling degree of the air conditioning system can be accurately controlled by controlling the opening degree of the first adjusting valve 53 to enable the supercooling pipe section 52 to reach a better temperature, so that the heating effect of the air conditioner is optimal, and the heating energy efficiency is improved.

It should be noted that, although the steps S500 and S600 are described after the opening and closing of the subcooling valve are adjusted, the execution timing is not fixed, and those skilled in the art can adjust the steps without departing from the scope of the present application. For example, the steps S500 and S600 may be performed before the opening and closing of the subcooling valve is adjusted, or may be performed before or after other steps.

It should be noted that although the above embodiment determines that the heat exchange pipe section 51 is frosted when the outdoor ambient temperature is less than the temperature threshold, this is not the only condition for determining whether frosting is present, and those skilled in the art will understand that other determination conditions may be added to determine whether the supercooling pipe section 52 is frosted. For example, a humidity determination is added on the basis of the temperature determination, and when both the temperature and the humidity are smaller than a certain threshold, it is determined that the supercooling pipe section 52 has frosted.

The control method of the present application is described in detail below.

In a preferred embodiment, before step S400, the method for controlling an air conditioner further includes: the opening and closing of a plurality of subcooling valves (55a, 55b, 55c) are adjusted so as to minimize the effective length of the subcooling pipe section 52. Specifically, the effective length of the supercooling pipe section 52 may be controlled to be the shortest when the heating mode is entered, or the effective length of the supercooling pipe section 52 may be controlled to be the shortest when the outdoor ambient temperature is determined to be less than the temperature threshold value or any other timing prior to collecting the temperature of the heat exchange pipe section 51. For example, referring to the embodiment shown in fig. 2, the effective length of the subcooling section 52 is controlled to be the shortest, that is, the number of subcooling sections capable of subcooling in the subcooling section 52 is controlled to be the smallest. In other words, by controlling the supercooling valve closest to the first end of the supercooling pipe section 52 to be closed, the remaining supercooling valves to be opened, the on-off valve closest to the first end of the supercooling pipe section 52 to be closed, and the remaining on-off valves to be closed, and controlling the confluence valve closest to the second end of the first regulation valve 53 to be opened and the remaining confluence valves to be closed, the supercooling valves 55a are controlled to be closed, the confluence valves 57a are controlled to be opened, the

confluence valves

57b and 57c are controlled to be closed, and the on-off valves 58a are controlled to be opened, and the

confluence valves

58b and 58c are controlled to be closed. The effective length of the subcooling tube section 52 at this time is the length of the first subcooling section from the first end (lower end in fig. 2) of the subcooling tube section 52.

In a preferred embodiment, step S400 may further include: acquiring and recording the temperature of the heat exchange pipe section 51 in a set time period every other set time period; calculating a rate of change of the temperature of the heat exchange tube section 51 within a set period of time based on the temperature and the set period of time; comparing the temperature change rate with a set threshold value; when the temperature change rate is larger than a set threshold value and lasts for a preset time, opening and closing of a plurality of supercooling valves (55a, 55b and 55c) are adjusted to increase the effective length of the supercooling pipe section 52 until the effective length of the supercooling pipe section 52 is increased to the longest; adjusting the opening and closing of a plurality of confluence valves (57a, 57b, 57c) simultaneously with, before or after adjusting the opening and closing of a plurality of supercooling valves (55a, 55b, 55c) so that the portions other than the effective length communicate with the heat exchange pipe section 51; and adjusting the opening and closing of the plurality of on-off valves (58a, 58b, 58c) to cut off the communication between the portion other than the effective length and the effective length, simultaneously with, before, or after adjusting the opening and closing of the plurality of supercooling valves (55a, 55b, 55 c).

Specifically, the set time period may be any value between 2min and 5min, or may be other values. After acquiring and recording the temperature of the heat exchange tube section 51 within the set period of time, the rate of change of the temperature of the heat exchange tube section 51 within the set period of time may be calculated based on the following equation (1):

in the formula (1), K represents that the heat exchange tube section 51 is in a set time periodThe rate of temperature change of; t is a unit of_nFor setting the temperature, T, of the nth sampling point in a time period_n-1And t is the interval time between the nth sampling point and the (n-1) th sampling point for setting the temperature of the (n-1) th sampling point in the time period.

When the temperature change rate is calculated to be less than or equal to a certain set threshold value and lasts for a preset time, if the set threshold value is-1, the preset time is 1min, and when K is less than or equal to-1 and lasts for 1min, the heat exchange tube section 51 is proved to be frosted rapidly at the moment so that the temperature of the coil pipe continuously drops. Also, the current effective length of the subcooling section 52 carries insufficient hot gas flow to defrost the heat exchange section 51, requiring increased defrosting capacity. At this time, by adjusting the opening and closing of the subcooling valves (55a, 55b, 55c), the merge valves (57a, 57b, 57c), and the on-off valves (58a, 58b, 58c), the effective length of the subcooling pipe section 52 can be increased, the heat exchange length of the subcooling pipe section 52 can be increased, the defrosting capacity can be improved, and the portions other than the effective length can be communicated with the heat exchange pipe section 51. For example, also taking the air conditioner shown in fig. 2 as an example, in the case where the effective length of the supercooling pipe section 52 is the shortest, by controlling the supercooling valves 55b to be closed, 55a and 55c to be opened, the confluence valves 57b to be opened, 57a and 57c to be closed, and the on-off valves 58b to be opened, 58a and 58c to be closed, the effective length of the supercooling pipe section 52 is increased to the sum of the lengths of the first supercooling section and the second supercooling section from the first end of the supercooling pipe section 52, the third to fourth supercooling sections are connected to the heat exchange pipe section 51, and the communication between the third to fourth supercooling sections and the first to second supercooling sections is cut off. And so on until the effective length of the subcooled tube section 52 increases to a maximum. On the contrary, when the calculated temperature change rate K is more than-1 or the time with K less than or equal to-1 does not last for 1min, the heat exchange pipe section 51 is proved not frosted or not frosted seriously at this time, and the heat exchange effect is good, so that the supercooling valve does not need to be adjusted, and only the supercooling valve needs to be controlled to keep the current state.

By adjusting the effective length of the supercooling pipe section 52 at set time intervals based on the change rate of the temperature, the control method can correspondingly adjust the defrosting capacity based on the frosting condition of the current heat exchange pipe section 51, improve the defrosting effect, avoid the condition that the defrosting capacity is not matched with the frosting degree, and ensure the heating efficiency. By adjusting the opening and closing of the confluence valves (57a, 57b, 57c) at the same time, before or after the opening and closing of the subcooling valves (55a, 55b, 55c) are adjusted so that the part except the effective length is communicated with the heat exchange tube section 51, the control method can reasonably utilize the part except the effective length as the supplement of the heat exchange tube section 51, and improve the evaporation heat exchange effect. The control method can also improve the utilization rate of the refrigerant in the supercooling pipe section 52 and ensure the heat exchange efficiency by adjusting the opening and closing of the on-off valves (58a, 58b, 58c) at the same time, before or after the opening and closing of the supercooling valves (55a, 55b, 55c) are adjusted to cut off the communication between the part except the effective length and the effective length.

Of course, the above embodiment is described in conjunction with the air conditioner shown in fig. 2, and it can be understood by those skilled in the art that, when the air conditioner is set in other forms, the above embodiment may be adjusted accordingly, and some steps may be added or deleted appropriately, so that the control method of the present application can have better applicability. For example, when the air conditioner is in the installation mode as shown in fig. 1, the step of adjusting the opening and closing of the confluence valve can be omitted; when the air conditioner is in the arrangement mode as shown in fig. 3 or 4, the step of adjusting the on-off valve to open and close can be omitted; when the air conditioner is only provided with the supercooling valve, the steps of adjusting the opening and closing of the confluence valve and the on-off valve and the like can be simultaneously omitted.

Besides, the method of comparing the temperature change rate with the set threshold value can be adopted, and the conclusion whether the superheat tube section is frosted can be obtained in other ways. For example, whether the heat exchange tube section 51 is frosted or not may be determined by rounding down the temperature change rate K and determining whether or not the result is smaller than the set threshold value, that is, whether or not int (K) is smaller than the set threshold value (for example, whether or not it is smaller than 0), or whether or not the heat exchange tube section 51 is frosted or not may be determined by integrating the temperature change amount in the set time period and calculating the magnitude of the integration result and the set value.

In a preferred embodiment, the first regulating valve 53 is a solenoid valve or an electronic expansion valve, and the step S500 further includes: acquiring the outdoor environment temperature and the working frequency of a compressor; calculating the theoretical temperature of the subcooling tube section 52 based on the outdoor ambient temperature; the operation opening degree of the first regulation valve 53 is calculated based on the outdoor ambient temperature, the operating frequency, and the theoretical temperature.

For example, the outdoor ambient temperature may be obtained by a temperature sensor provided on the outdoor unit, the operating frequency of the compressor may be obtained based on the operating parameters when the inverter air conditioner is in operation, and then the theoretical temperature of the supercooling pipe section 52 may be calculated by using the following formula (2):

T_c＝k×T_ao+p (2)

in the formula (2), T_cIs the theoretical temperature of the subcooling tube section 52; t is a unit of_aoIs the outdoor ambient temperature; k. p is a constant that can be fit based on experimental data, e.g., multiple experiments on the air conditioner for different outdoor ambient temperatures. In the experiment, based on different outdoor environment temperatures, the temperature of the supercooling pipe section 52 is adjusted, so that the heat exchange effect under the condition is optimal, and the temperature of the supercooling pipe section 52 with the optimal heat exchange effect is recorded as the theoretical temperature under the condition. After multiple tests, the values of the constants k and p are calculated by using a linear fitting method, so that a fitting formula between the outdoor environment temperature and the theoretical temperature of the supercooling pipe section 52 is obtained.

It can be understood by those skilled in the art that the theoretical temperature of the overcooling pipe section 52 determines the heat exchange effect and the defrosting effect of the overcooling pipe section 52, and indirectly determines the heating energy efficiency, and the heat exchange effect of the overcooling pipe section 52 has a direct relation with the outdoor environment temperature, when the temperature difference between the outdoor environment temperature and the overcooling pipe section 52 reaches a certain range, the overcooling degree of the air conditioning system also reaches a better state, and the theoretical temperature of the overcooling pipe section 52 is calculated based on the outdoor environment temperature, the control method of the application can correlate the theoretical temperature of the overcooling pipe section 52 with the outdoor environment temperature, and on the basis of ensuring the optimal overcooling degree and the overcooling effect of the outdoor heat exchanger, the power of the compressor is reduced, and the heating effect is improved.

Of course, the determination of the theoretical temperature is not limited to the method shown in equation (2) above, and equation (2) may be replaced by any method for determining the theoretical temperature of the subcooling section 52 from the outdoor ambient temperature without departing from the principles of the present application. The specific value of the theoretical temperature may also be determined by the correspondence between the outdoor ambient temperature and the theoretical temperature of the supercooled section 52, for example.

In a more preferred embodiment, the following fitting formula (3) may be used to calculate the operation opening degree of the first regulating valve 53:

B＝a₁×f+b₁×T_ao+c₁×Int(T_c-T_ao) (3)

in the formula (3), B is the operation opening degree of the first regulating valve 53; f is the working frequency of the compressor; t is_cIs the theoretical temperature of the subcooling tube section 52; t is_aoIs the outdoor ambient temperature; int (T)_c-T_ao) To perform a rounding operation on the difference between the theoretical temperature of the supercooling pipe section 52 and the outdoor ambient temperature; a is₁、b₁、c₁As constants, the constants can be fit based on experimental data. For example, the heating energy efficiency of the air conditioner is tested several times for different outdoor ambient temperatures, compressor frequencies, and theoretical temperatures of the supercooling duct section 52. In the experiment, the opening degree of the first regulating valve 53 is adjusted so that the heating energy efficiency of the air conditioner is minimized, and the opening degree parameter of the first regulating valve 53 corresponding to the current heating energy efficiency is recorded as the operation opening degree of the first regulating valve 53 under the condition. After a number of tests, the constant a is calculated₁、b₁、c₁To obtain a fit equation between the first regulating valve 53 and the outdoor ambient temperature, the compressor frequency and the theoretical temperature of the subcooling tube section 52.

By jointly determining the operation opening degree of the first regulating valve 53 based on the working frequency of the compressor, the theoretical temperature of the supercooling pipe section 52 and the outdoor environment temperature, the control method can jointly determine the operation opening degree of the first regulating valve 53 based on various variable quantities, improves the calculation accuracy of the operation opening degree, enables the first regulating valve 53 to constantly work at a proper opening degree, and reduces the heating energy consumption of the air conditioner.

Of course, the determination of the operating opening of the first regulating valve 53 may also be based on other relationships with the above-mentioned parameters, such as the fixed correspondence between the above-mentioned three parameters and the operating opening.

In a more preferred embodiment, after "adjusting the opening degree of the first regulating valve 53 to the operation opening degree", the heating control method further includes: acquiring the actual temperature of the supercooling pipe section 52; the opening degree of the first regulating valve 53 is PID-regulated based on the difference between the theoretical temperature and the actual temperature.

By performing PID control on the opening degree of the first regulating valve 53 based on the difference between the theoretical temperature and the actual temperature of the supercooling pipe section 52 after adjusting the opening degree of the first regulating valve 53 to the operating opening degree, the control method of the present application can also dynamically, quickly, and accurately regulate the opening degree of the first regulating valve 53, preventing the first regulating valve 53 from overshooting or overshooting.

In a more preferred embodiment, after step S600, the control method further includes: acquiring the outdoor environment temperature and the running frequency of a compressor; calculating a heating target exhaust temperature of the air conditioner based on the outdoor environment temperature and the operation frequency; the opening degree of the second regulating valve 7 is controlled based on the heating target exhaust gas temperature. Preferably, the above steps may be performed after the PID adjustment of the opening degree of the first adjusting valve 53, that is, in the PID adjustment of the opening degree of the first adjusting valve 53, when the actual temperature of the supercooling pipe section 52 reaches the theoretical temperature, the outdoor ambient temperature and the operation frequency of the compressor are acquired, and the heating target discharge temperature is calculated based on the outdoor ambient temperature and the operation frequency of the compressor, and the opening degree of the second adjusting valve 7 is controlled based thereon. Wherein, the heating target exhaust temperature of the air conditioner can be calculated by the following formula (4):

T_{target_heat}＝a₂×f+b₂×(T_ao-7)+c₂ (4)

in the formula (4), T_{target_heat}Is the heating target exhaust temperature of the air conditioner; f is the working frequency of the compressor; t is_aoIs the outdoor ambient temperature; a is₂、b₂、c₂The constants may be obtained by fitting based on experimental data, and the method for obtaining the constants is similar to that described above and will not be described herein again.

It will be understood by those skilled in the art that the opening of the second regulating valve 7 directly determines the effect of the first throttling and cooling during the heating process, and the control of the first regulating valve 53 determines the energy efficiency of the heating operation. According to the control method, the first regulating valve 53 and the second regulating valve 7 are subjected to linkage control during heating, particularly, the opening degree of the second regulating valve 7 is regulated on the basis of controlling the first regulating valve 53, so that the operation parameters of the air conditioner can be always kept in the optimal state, the operation effect of the air conditioner is ensured, and meanwhile, the energy efficiency of the air conditioner is improved.

Of course, the determination of the heating target discharge temperature is not limited to the method shown in the above equation (4), and the equation (4) may be replaced by any method for determining the heating target discharge temperature through the outdoor environment temperature and the operating frequency of the compressor without departing from the principles of the present application. Furthermore, there are various schemes in the prior art for controlling the second regulating valve 7 based on the heating target exhaust temperature, such as proportional regulation, PID regulation, etc., which can be applied to the control method of the present application and are not described herein again. Although the present embodiment has been described with reference to the procedure of performing the opening degree control of the second regulating valve 7 after performing the PID control of the first regulating valve 53, this control method is not absolute, and performing the PID control of the first regulating valve 53 is only a verification step for preventing the overshoot or overshoot of the first regulating valve 53, and is not essential, and therefore, it is theoretically possible to improve the heating energy efficiency by performing the opening degree control of the second regulating valve 7 simultaneously with or before performing the PID control of the first regulating valve 53.

In a preferred embodiment, the control method further includes:

when the air conditioner operates in a refrigerating mode, the first regulating valve 53 is controlled to be fully opened; acquiring the outdoor environment temperature and the working frequency of a compressor; calculating a target cooling exhaust temperature of the air conditioner based on the outdoor environment temperature and the working frequency; the opening degree of the second regulating valve 7 is controlled based on the cooling target exhaust gas temperature. Wherein the cooling target discharge temperature of the air conditioner may be calculated using the following formula (5):

T_{target_cool}＝a₃×f+b₃×(T_ao-35)+c₃ (5)

in the formula (5), T_{target_cool}Is the refrigeration target exhaust temperature of the air conditioner; f is the working frequency of the compressor; t is_aoIs the outdoor ambient temperature; a is₃、b₃、c₃The constants may be obtained by fitting based on experimental data, and the method for obtaining the constants is similar to that described above and will not be described herein again.

When the air conditioner is used for refrigeration, the first adjusting valve 53 can be prevented from influencing refrigeration energy efficiency by fully opening the first adjusting valve 53, normal adjustment of the air conditioner can be realized by adjusting the opening degree of the second adjusting valve 7 based on the refrigeration target exhaust temperature, and the refrigeration effect and the refrigeration energy efficiency are ensured.

Of course, similarly to the above, the determination of the cooling target discharge temperature is not limited to the method shown in the above equation (5), and equation (5) may be replaced by any method for determining the cooling target discharge temperature by the outdoor ambient temperature and the operating frequency of the compressor without departing from the principles of the present application. Furthermore, there are various schemes in the prior art for controlling the second regulating valve 7 based on the target cooling discharge temperature, such as adopting proportional regulation, PID regulation, etc., which all can be applied to the control method of the present application, and therefore, the details are not described.

Next, referring to fig. 2 and 6, a control process of the control method of the air conditioner of the present application will be briefly described. Fig. 6 is a logic diagram of a control method of an air conditioner according to the present invention.

In one possible implementation, as shown in fig. 2 and 6, the air conditioner is operated to heat → first obtains the outdoor ambient temperature T_aoJudgment of T_aoWhether < 5 ℃ is true:

if T is_aoIf < 5 ℃ fails, the effective length of the subcooled tube section 52 is adjusted to the shortest (if already shortest, then there is no need to do so)Adjustment) and keeping the state to continuously operate → obtaining the outdoor environment temperature T during operation_aoAnd the operating frequency f → of the compressor → the theoretical temperature T of the supercooling pipe section 52 is calculated based on the formula (2)_c→ based on the formula (3), calculating the operation opening B of the first adjusting valve 53 → controlling the first adjusting valve 53 to open to the opening B, so that the air conditioner operates with better heating efficiency and defrosting efficiency → the air conditioner operates for 2min, and then detects the actual temperature T of the supercooling pipe_c1→ calculation of the theoretical temperature T_cAnd the actual temperature T_c1The difference value delta T between the two, and PID accurate adjustment is carried out on the opening degree of the first adjusting valve 53 based on the difference value delta T, so that the heating energy efficiency of the air conditioner is ensured, the first adjusting valve 53 is prevented from overshooting or overshooting → during the PID adjustment process, whether the actual temperature of the supercooling pipe section 52 reaches the theoretical temperature is judged → when the actual temperature reaches the theoretical temperature, the outdoor environment temperature T is obtained_aoAnd an operating frequency f of the compressor, and calculates a heating target exhaust temperature T based on the formula (4)_{target_heat}→ based on the heating target exhaust temperature T_{target_heat}The opening degree of the second regulating valve 7 is controlled to optimize the operation state and the heating efficiency of the air conditioner.

If T_aoIf < 5 ℃ is established, the effective length of the supercooling pipe section 52 is first adjusted to the shortest, and the temperature of the heat exchange pipe section 51 is continuously detected for a set period of 2min and the rate of change of temperature K within the 2min is calculated based on the formula (1) < 1 > if K.ltoreq.1 and for 1min, the opening and closing of the supercooling valves (55a, 55b, 55c), the confluence valves (57a, 57b, 57c), and the on-off valves (58a, 58b, 58c) are controlled to increase the effective length of the supercooling pipe section 52 → after the effective length of the supercooling pipe section 52 is increased, the outdoor ambient temperature T is acquired_aoAnd the operating frequency f → of the compressor → the theoretical temperature T of the supercooling pipe section 52 is calculated based on the formula (2)_cCalculating an operation opening B of the first adjusting valve 53 based on the formula (3) → controlling the first adjusting valve 53 to be opened to the opening B so that the air conditioner operates with preferable heating efficiency and defrosting efficiency → operating the air conditioner for 2min, and then detecting an actual temperature T of the supercooling pipe_c1→ calculation of the theoretical temperature T_cAnd the actual temperature T_c1A difference value Delta T between the two and based on the difference value Delta T, the first regulating valveThe opening degree of the first adjusting valve 53 is accurately adjusted through PID (proportion integration differentiation), the heating energy efficiency of the air conditioner is guaranteed, the first adjusting valve 53 is prevented from being overmuch or overshot → in the PID adjusting process, whether the actual temperature of the supercooling pipe section 52 reaches the theoretical temperature is judged → when the actual temperature reaches the theoretical temperature, the outdoor environment temperature T is obtained_aoAnd an operating frequency f of the compressor, and calculates a heating target exhaust temperature T based on the formula (4)_{target_heat}→ based on the heating target exhaust temperature T_{target_heat}Controlling the opening degree of the second regulating valve 7 to make the running state and the heating efficiency of the air conditioner reach the best → after the regulation is finished, returning to the step of repeatedly collecting the temperature of the heat exchange pipe section 51, regulating the effective length of the supercooling pipe based on the temperature change rate K and regulating the opening degree B of the first regulating valve 53 until the effective length of the supercooling pipe section 52 is increased to the maximum.

Those skilled in the art will appreciate that the inverter air conditioner described above further includes some other known structures, such as a processor, a controller, a memory, etc., wherein the memory includes, but is not limited to, a random access memory, a flash memory, a read only memory, a programmable read only memory, a volatile memory, a non-volatile memory, a serial memory, a parallel memory or a register, etc., and the processor includes, but is not limited to, a CPLD/FPGA, a DSP, an ARM processor, a MIPS processor, etc. Such well-known structures are not shown in the drawings in order to not unnecessarily obscure embodiments of the present disclosure.

The various component embodiments of the invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art will appreciate that a microprocessor or Digital Signal Processor (DSP) may be used in practice to implement some or all of the functionality of some or all of the components in a server, client, or the like, according to embodiments of the present invention. The present invention may also be embodied as an apparatus or device program (e.g., PC program and PC program product) for carrying out a portion or all of the methods described herein. Such a program implementing the invention may be stored on a PC readable medium or may be in the form of one or more signals. Such a signal may be downloaded from an internet website or provided on a carrier signal or in any other form.

It should be noted that although the detailed steps of the method of the present invention are described in detail, those skilled in the art can combine, separate and change the order of the above steps without departing from the basic principle of the present invention, and the modified technical solution does not change the basic idea of the present invention and therefore falls into the protection scope of the present invention.

Finally, although the present embodiment is described in conjunction with an inverter air conditioner, this is not intended to limit the scope of the present application, and those skilled in the art can also apply the present application to other types of air conditioners as long as the air conditioner has an outdoor unit condenser. For example, the present application can also be applied to a constant frequency air conditioner or the like.

So far, the technical solutions of the present invention have been described in connection with the preferred embodiments shown in the drawings, but it is apparent to those skilled in the art that the scope of the present invention is not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the invention, and the technical scheme after the changes or substitutions can fall into the protection scope of the invention.

Claims

1. A control method of an air conditioner is characterized in that the air conditioner comprises a compressor, an outdoor unit condenser, a second regulating valve and an indoor unit evaporator, the outdoor unit condenser comprises a heat exchange pipe section, an supercooling pipe section, a first regulating valve, a supercooling connecting pipe and a plurality of supercooling valves, a first end of the supercooling pipe section is connected with the indoor unit evaporator through the second regulating valve, a first end and a second end of the supercooling pipe section are divided into n supercooling sections by the plurality of supercooling valves, the plurality of supercooling sections are respectively connected with the first end of the first regulating valve through the supercooling connecting pipe, and the second end of the first regulating valve is connected with the heat exchange pipe section,

the control method comprises the following steps:

when heating operation is performed, the outdoor environment temperature is obtained;

when the outdoor environment temperature is smaller than the temperature threshold value, acquiring the temperature of the heat exchange pipe section;

determining the operation opening degree of the first regulating valve;

adjusting the opening degree of the first regulating valve to the operation opening degree;

the step of selectively adjusting the opening and closing of the number of subcooling valves based on the temperature of the heat exchange tube segment further comprises:

comparing the temperature change rate with a set threshold value;

when the temperature change rate is greater than the set threshold value and lasts for a preset time, adjusting the opening and closing of the plurality of supercooling valves to increase the effective length of the supercooling pipe section until the effective length of the supercooling pipe section is increased to the longest length;

wherein the effective length refers to the length of a pipe section which plays a role of supercooling in the supercooling pipe section, and the effective length is the longest, namely the whole length of the supercooling pipe section.

2. The control method of an air conditioner according to claim 1, wherein before the step of selectively adjusting the opening and closing of the plurality of supercooling valves, the control method further comprises:

3. The method of claim 1, wherein a second end of the supercooling pipe section is connected to the heat exchange pipe section, the outdoor unit condenser further includes a confluence connection pipe and a plurality of confluence valves, each of the plurality of supercooling sections is connected to the second end of the first control valve through one of the confluence connection pipes, and each of the confluence connection pipes is provided with one of the confluence valves, the method further comprising:

4. The method of claim 1, wherein the outdoor unit condenser further includes a plurality of on-off valves, and one of the on-off valves is disposed on each of the plurality of subcooling connecting pipes, and the method further comprises:

adjusting the opening and closing of the plurality of on-off valves to intercept the communication between the portion other than the effective length and the effective length, simultaneously with, before, or after the adjustment of the opening and closing of the plurality of supercooling valves.

5. The control method of an air conditioner according to claim 1, further comprising:

6. The control method of an air conditioner according to claim 1, wherein the step of "determining the operation opening degree of the first regulating valve" further comprises:

and calculating the operation opening degree of the first regulating valve based on the outdoor environment temperature, the working frequency and the theoretical temperature.

7. The control method of an air conditioner according to claim 6, characterized in that after the step of "adjusting the first regulating valve opening degree to the operation opening degree", the control method further comprises:

acquiring the actual temperature of the supercooling pipe section;

8. The control method of an air conditioner according to claim 7, characterized in that after the step of "adjusting the first regulating valve opening degree to the operation opening degree", the control method further comprises:

calculating a heating target discharge temperature of the air conditioner based on the outdoor ambient temperature and the operating frequency;

9. The control method of an air conditioner according to claim 8, wherein the step of "acquiring the outdoor ambient temperature and the operating frequency of the compressor" further comprises: